diff --git a/.changelog/lang_zh-Hans.json b/.changelog/lang_zh-Hans.json
index 7538177f..cd4cad9c 100644
--- a/.changelog/lang_zh-Hans.json
+++ b/.changelog/lang_zh-Hans.json
@@ -33,6 +33,7 @@
"文件管理器浮动按钮展开后点击其他区域可自动隐藏",
"打包单文件时自动读取并勾选已安装应用的声明权限 _[`issue #362`](http://issues.autojs6.com/362)_",
"意图相关操作 (编辑/查看/安装/发送/播放等) 增加操作异常提示",
+ "images.save 方法使用 quality 参数时支持 png 格式的文件体积压缩 _[`issue #367`](http://issues.autojs6.com/367)_",
"已忽略更新记录及客户端模式连接地址记录支持清空操作",
"版本更新信息支持多语言显示 (与当前显示语言同步)",
"使用异步加载方式一定程度提升文件管理器列表滑动流畅性",
@@ -41,6 +42,8 @@
"dependency": [
"本地化 Material Dialogs 版本 0.9.6.0",
"本地化 Material Date Time Picker 版本 4.2.3",
+ "本地化 libimagequant 版本 2.17.0",
+ "本地化 libpng 版本 1.6.49",
"附加 Jsoup 版本 1.19.1",
"附加 Material Progressbar 版本 1.4.2",
"附加 Flexmark Java HTML to Markdown 版本 0.64.8",
diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index b1611a59..42161dca 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -163,6 +163,9 @@ dependencies /* Unclassified */ {
// RapidOCR
implementation(project(":libs:rapidocr"))
+ // Image Quantization
+ implementation(project(":libs:imagequant"))
+
// Android Job
implementation(project(":libs:android-job-simplified-1.4.3"))
@@ -623,6 +626,7 @@ android {
"junit/**/*",
"LICENSE-junit.txt",
"spec.txt",
+ "EmojiReference.txt",
).let { resources.excludes.addAll(it) }
if (gradle.startParameter.taskNames.any { it.contains(flavorNameInrt, true) }) {
diff --git a/app/src/main/java/org/autojs/autojs/apkbuilder/ApkBuilder.kt b/app/src/main/java/org/autojs/autojs/apkbuilder/ApkBuilder.kt
index f2e6610f..97aeeb59 100644
--- a/app/src/main/java/org/autojs/autojs/apkbuilder/ApkBuilder.kt
+++ b/app/src/main/java/org/autojs/autojs/apkbuilder/ApkBuilder.kt
@@ -546,10 +546,33 @@ open class ApkBuilder(apkInputStream: InputStream?, private val outApkFile: File
MLKIT_BARCODE(
label = "MLKit Barcode",
aliases = listOf("barcode", "mlkit-barcode", "mlkit_barcode"),
+ libsToInclude = listOf(
+ "libbarhopper_v3.so",
+ ),
assetDirsToExclude = listOf(
"mlkit_barcode_models",
),
- );
+ ),
+
+ MEDIA_INFO(
+ label = "MediaInfo",
+ aliases = listOf("mediainfo", "media-info", "media_info"),
+ libsToInclude = listOf(
+ "libmediainfo.so",
+ ),
+ ),
+
+ IMAGE_QUANT(
+ label = "Image Quantization",
+ aliases = listOf("imagequant", "image-quant", "image-quantization", "image_quant", "image_quantization"),
+ libsToInclude = listOf(
+ "libpng.so",
+ "libpng16d.so",
+ "libpngquant_bridge.so",
+ ),
+ ),
+
+ ;
fun ensureLibFiles(moduleName: String = label) {
if (!isInrt) return
diff --git a/app/src/main/java/org/autojs/autojs/runtime/api/ImageFeatureMatching.java b/app/src/main/java/org/autojs/autojs/runtime/api/ImageFeatureMatching.java
index c0e2b693..a893bc43 100644
--- a/app/src/main/java/org/autojs/autojs/runtime/api/ImageFeatureMatching.java
+++ b/app/src/main/java/org/autojs/autojs/runtime/api/ImageFeatureMatching.java
@@ -61,7 +61,7 @@ public final class ImageFeatureMatching {
* reused later by {@link #featureMatching}
*
*
- * zh-CN
+ *
zh-CN:
*
* 创建 (预计算) 特征匹配描述符.
* 典型流程:
@@ -168,7 +168,7 @@ public final class ImageFeatureMatching {
* If caller sets {@code debugMatchesImagePath}, save visualization of match lines to that path
*
*
- * zh-CN
+ *
zh-CN:
*
* 在两张图的特征描述符之间执行匹配, 并 (可选) 估算单应矩阵以获得被 object 图在 scene 图中的投影区域.
*
内部流程:
diff --git a/app/src/main/java/org/autojs/autojs/runtime/api/Images.java b/app/src/main/java/org/autojs/autojs/runtime/api/Images.java
index 535d29ef..fb4a580c 100644
--- a/app/src/main/java/org/autojs/autojs/runtime/api/Images.java
+++ b/app/src/main/java/org/autojs/autojs/runtime/api/Images.java
@@ -35,6 +35,8 @@ import org.autojs.autojs.core.ui.inflater.util.Drawables;
import org.autojs.autojs.pio.UncheckedIOException;
import org.autojs.autojs.runtime.ScriptRuntime;
import org.autojs.autojs.runtime.api.ImageFeatureMatching.FeatureMatchingDescriptor;
+import org.autojs.autojs.runtime.exception.WrappedRuntimeException;
+import org.autojs.autojs.util.BitmapUtils;
import org.autojs.autojs6.R;
import org.jetbrains.annotations.Contract;
import org.jetbrains.annotations.NotNull;
@@ -254,13 +256,38 @@ public class Images {
return imageWrapper;
}
- public boolean save(@NonNull ImageWrapper image, String path, String format, int quality) throws IOException {
- Bitmap.CompressFormat compressFormat = parseImageFormat(format);
+ public boolean save(@NonNull ImageWrapper image,
+ @NonNull String path,
+ @NonNull String format,
+ int quality) throws IOException {
+
Bitmap bitmap = image.getBitmap();
- FileOutputStream outputStream = new FileOutputStream(path);
- boolean b = bitmap.compress(compressFormat, quality, outputStream);
- image.shoot();
- return b;
+ Bitmap.CompressFormat compressFormat = parseImageFormat(format);
+
+ if (compressFormat == Bitmap.CompressFormat.PNG && quality != 100) {
+ // ARGB_8888 -> RGBA[]
+ byte[] rgba = BitmapUtils.bitmapToRgba(bitmap);
+ byte[] compressed = PngQuantBridge.quantize(rgba, bitmap.getWidth(), bitmap.getHeight(), quality);
+ if (compressed != null) {
+ try (FileOutputStream fos = new FileOutputStream(path)) {
+ fos.write(compressed);
+ return true;
+ }
+ }
+ throw new WrappedRuntimeException("PNG quantization failed");
+ }
+
+ if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+ if (compressFormat == Bitmap.CompressFormat.WEBP_LOSSLESS && quality != 100) {
+ throw new IllegalArgumentException(mContext.getString(R.string.error_webp_lossless_quality_not_supported));
+ }
+ }
+
+ try (FileOutputStream fos = new FileOutputStream(path)) {
+ boolean b = bitmap.compress(compressFormat, quality, fos);
+ image.shoot();
+ return b;
+ }
}
// public EventEmitter select() {
@@ -357,13 +384,13 @@ public class Images {
case "png" -> Bitmap.CompressFormat.PNG;
case "jpeg", "jpg" -> Bitmap.CompressFormat.JPEG;
case "webp" -> Bitmap.CompressFormat.WEBP;
- case "webp_lossy" -> {
+ case "webp_lossy", "webp-lossy" -> {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
yield Bitmap.CompressFormat.WEBP_LOSSY;
}
throw new IllegalArgumentException("Image format \"WEBP_LOSSY\" only supports on Android API Level 30 (11) [R] and above");
}
- case "webp_lossless" -> {
+ case "webp_lossless", "webp-lossless" -> {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
yield Bitmap.CompressFormat.WEBP_LOSSLESS;
}
diff --git a/app/src/main/java/org/autojs/autojs/runtime/api/PngQuantBridge.java b/app/src/main/java/org/autojs/autojs/runtime/api/PngQuantBridge.java
new file mode 100644
index 00000000..8dbc2b9b
--- /dev/null
+++ b/app/src/main/java/org/autojs/autojs/runtime/api/PngQuantBridge.java
@@ -0,0 +1,46 @@
+package org.autojs.autojs.runtime.api;
+
+public class PngQuantBridge {
+
+ static {
+ System.loadLibrary("pngquant_bridge");
+ }
+
+ /**
+ * Quantizes a 32-bit RGBA image to an 8-bit indexed PNG and returns the encoded bytes.
+ *
+ * The routine converts the input buffer (RGBA8888) to a palette-based image through
+ * libimagequant and then writes it out as PNG8. The PNG/Deflate stage that follows
+ * is strictly lossless—the stream produced by this method can always be inflated
+ * back to the same 8-bit palette data byte-for-byte.
+ *
+ * The potentially visible degradation comes solely from the color quantization step:
+ * ~16.7 M true-color values are mapped to ≤256 palette entries. How noticeable this mapping is
+ * depends on both the source image and the {@code quality} you request.
+ *
+ * - {@code quality} represents the upper limit of Mean Square Error × 10 accepted
+ * by libimagequant (range 0–100). Lower numbers allow larger error, producing smaller files.
+ * - Because many graphics are well represented with 256 colors, even an extremely low
+ * {@code quality} such as {@code 1} may look almost identical to the original while shrinking
+ * to 5–20 % of its former size.
+ * - No further lossy step exists during PNG writing; the format itself does not permit it.
+ *
+ * zh-CN:
+ * 该方法把 32 位 RGBA 图像量化为 8 位索引色 PNG, 并返回编码后的字节数组.
+ * PNG 的 Deflate 压缩阶段完全无损; 图像失真来自量化过程: 32 位真彩被映射到
+ * ≤256 色调色板, 失真程度由 {@code quality} 决定.
+ *
+ * - {@code quality} 取值 0–100, 对应 libimagequant 允许的 （MSE×10）上限; 数值越小, 容许误差越大, 文件越小.
+ * - 许多图片用 256 色即可精准表示, 因此即便 {@code quality}=1 也可能与原图几乎无差别, 体积却可缩至原来的 5–20 %.
+ * - PNG 规范不支持在压缩阶段引入有损处理, 因此不会像 JPEG 那样再出现马赛克等失真.
+ *
+ *
+ * @param rgba contiguous RGBA8888 buffer; length must equal {@code width * height * 4}
+ * @param width image width in pixels
+ * @param height image height in pixels
+ * @param quality libimagequant quality (0–100, lower = smaller file & potentially higher error)
+ * @return palette-based PNG bytes (may contain transparency)
+ */
+ public static native byte[] quantize(byte[] rgba, int width, int height, int quality);
+
+}
\ No newline at end of file
diff --git a/app/src/main/java/org/autojs/autojs/runtime/api/augment/Augmentable.kt b/app/src/main/java/org/autojs/autojs/runtime/api/augment/Augmentable.kt
index 0dd5041f..14dec266 100644
--- a/app/src/main/java/org/autojs/autojs/runtime/api/augment/Augmentable.kt
+++ b/app/src/main/java/org/autojs/autojs/runtime/api/augment/Augmentable.kt
@@ -143,8 +143,19 @@ abstract class Augmentable(private val scriptRuntime: ScriptRuntime? = null) : F
try {
(this as Invokable).invoke(*args)
} catch (e: Exception) {
- val message = e.message?.let {
- globalContext.getString(R.string.error_failed_to_call_method_with_cause, key, it)
+ val message = e.message?.let { msg ->
+ when {
+ msg.contains("\n") -> {
+ msg.split("\n").let { split ->
+ globalContext.getString(R.string.error_failed_to_call_method_with_cause, key, split.first()).let { result ->
+ split.slice(1..split.lastIndex).joinToString("\n").takeUnless { it.isBlank() }?.let {
+ "$result\n$it"
+ } ?: result
+ }
+ }
+ }
+ else -> globalContext.getString(R.string.error_failed_to_call_method_with_cause, key, msg)
+ }
} ?: globalContext.getString(R.string.error_failed_to_call_method, key)
throw WrappedRuntimeException(message, e)
}
diff --git a/app/src/main/java/org/autojs/autojs/runtime/api/augment/images/Images.kt b/app/src/main/java/org/autojs/autojs/runtime/api/augment/images/Images.kt
index 35713f4c..6e79d03e 100644
--- a/app/src/main/java/org/autojs/autojs/runtime/api/augment/images/Images.kt
+++ b/app/src/main/java/org/autojs/autojs/runtime/api/augment/images/Images.kt
@@ -1334,8 +1334,11 @@ class Images(scriptRuntime: ScriptRuntime) : Augmentable(scriptRuntime), AsEmitt
private fun parseImageFormat(o: Any?): String = when {
o.isJsNullish() -> "png"
- else -> when (val format = coerceString(o).lowercase()) {
+ else -> when (val format = coerceString(o).lowercase().trim()) {
+ "" -> "png"
"png", "jpg", "jpeg", "webp" -> format
+ "webp_lossless", "webp-lossless" -> format
+ "webp_lossy", "webp-lossy" -> format
else -> throw WrappedIllegalArgumentException("Unknown image format: $format")
}
}
diff --git a/app/src/main/java/org/autojs/autojs/util/BitmapUtils.kt b/app/src/main/java/org/autojs/autojs/util/BitmapUtils.kt
index 90280e1e..aa852cbc 100644
--- a/app/src/main/java/org/autojs/autojs/util/BitmapUtils.kt
+++ b/app/src/main/java/org/autojs/autojs/util/BitmapUtils.kt
@@ -34,4 +34,28 @@ object BitmapUtils {
.also { drawable.draw(Canvas(it)) }
}
+ @JvmStatic
+ fun bitmapToRgba(bmp: Bitmap): ByteArray {
+ val w = bmp.getWidth()
+ val h = bmp.getHeight()
+
+ require(w > 0 && h > 0) { "bitmap size is 0" }
+
+ val pixelCount = w * h
+ val byteCount = pixelCount * 4
+
+ val rgba = ByteArray(byteCount)
+ val argb = IntArray(pixelCount)
+ bmp.getPixels(argb, 0, w, 0, 0, w, h)
+
+ var i4 = 0
+ for (p in argb) {
+ rgba[i4++] = ((p shr 16) and 0xFF).toByte() // R
+ rgba[i4++] = ((p shr 8) and 0xFF).toByte() // G
+ rgba[i4++] = (p and 0xFF).toByte() // B
+ rgba[i4++] = ((p shr 24) and 0xFF).toByte() // A
+ }
+ return rgba
+ }
+
}
\ No newline at end of file
diff --git a/app/src/main/res/values-ar/strings.xml b/app/src/main/res/values-ar/strings.xml
index f2ef0b7d..e62bda17 100644
--- a/app/src/main/res/values-ar/strings.xml
+++ b/app/src/main/res/values-ar/strings.xml
@@ -1048,5 +1048,6 @@
لا توجد تطبيقات متاحة لعرض هذا الملف
لا توجد تطبيقات متاحة لإرسال هذا الملف
لا توجد تطبيقات متاحة لتشغيل هذا الملف
+ لا يمكن ضغط تنسيق WebP-Lossless باستخدام معامل الجودة؛ استخدم JPEG/PNG/WebP-Lossy بدلاً من ذلك
diff --git a/app/src/main/res/values-en/strings.xml b/app/src/main/res/values-en/strings.xml
index 9302d16d..00f617ef 100644
--- a/app/src/main/res/values-en/strings.xml
+++ b/app/src/main/res/values-en/strings.xml
@@ -1043,5 +1043,6 @@
No applications available for viewing this file
No applications available for sending this file
No applications available for playing this file
+ Format WebP-Lossless cannot be compressed with a quality parameter, use JPEG/PNG/WebP-Lossy instead
diff --git a/app/src/main/res/values-es/strings.xml b/app/src/main/res/values-es/strings.xml
index 4044f704..5e6b3cbd 100644
--- a/app/src/main/res/values-es/strings.xml
+++ b/app/src/main/res/values-es/strings.xml
@@ -1046,5 +1046,6 @@
No hay aplicaciones disponibles para ver este archivo
No hay aplicaciones disponibles para enviar este archivo
No hay aplicaciones disponibles para reproducir este archivo
+ El formato WebP-Lossless no se puede comprimir con un parámetro de calidad; usa JPEG/PNG/WebP-Lossy en su lugar
diff --git a/app/src/main/res/values-fr/strings.xml b/app/src/main/res/values-fr/strings.xml
index 03d6b118..d5d22eeb 100644
--- a/app/src/main/res/values-fr/strings.xml
+++ b/app/src/main/res/values-fr/strings.xml
@@ -1046,5 +1046,6 @@
Aucune application disponible pour afficher ce fichier
Aucune application disponible pour envoyer ce fichier
Aucune application disponible pour lire ce fichier
+ Le format WebP-Lossless ne peut pas être compressé avec un paramètre de qualité ; utilisez plutôt JPEG/PNG/WebP-Lossy
diff --git a/app/src/main/res/values-ja/strings.xml b/app/src/main/res/values-ja/strings.xml
index ebc4c5a8..40ada7f8 100644
--- a/app/src/main/res/values-ja/strings.xml
+++ b/app/src/main/res/values-ja/strings.xml
@@ -1047,5 +1047,6 @@
このファイルを表示できるアプリがありません
このファイルを送信できるアプリがありません
このファイルを再生できるアプリがありません
+ WebP-Lossless 形式は品質パラメータで圧縮できません, 代わりに JPEG/PNG/WebP-Lossy を使用してください
diff --git a/app/src/main/res/values-ko/strings.xml b/app/src/main/res/values-ko/strings.xml
index 04dd3ee9..c0c36f7b 100644
--- a/app/src/main/res/values-ko/strings.xml
+++ b/app/src/main/res/values-ko/strings.xml
@@ -182,7 +182,7 @@
너비 초과: 템플릿 [%1$d] > 영역 [%2$d]
현재 색상 기록 적용에 실패했습니다
메서드 \"%s\"를 호출하지 못했습니다
-
+
%s 값을 Drawable 로 변환하지 못했습니다
Shizuku 권한을 부여하지 못했습니다
\"%s\" 인스턴스 생성에 실패했습니다
@@ -1048,5 +1048,6 @@
이 파일을 볼 수 있는 앱이 없습니다
이 파일을 전송할 수 있는 앱이 없습니다
이 파일을 재생할 수 있는 앱이 없습니다
+ WebP-Lossless 형식은 품질 파라미터로 압축할 수 없습니다, 대신 JPEG/PNG/WebP-Lossy를 사용하세요
diff --git a/app/src/main/res/values-ru/strings.xml b/app/src/main/res/values-ru/strings.xml
index 5672bc26..254330e4 100644
--- a/app/src/main/res/values-ru/strings.xml
+++ b/app/src/main/res/values-ru/strings.xml
@@ -1046,5 +1046,6 @@
Нет приложений для просмотра этого файла
Нет приложений для отправки этого файла
Нет приложений для воспроизведения этого файла
+ Формат WebP-Lossless нельзя сжать с параметром качества; используйте вместо этого JPEG/PNG/WebP-Lossy
diff --git a/app/src/main/res/values-zh-rHK/strings.xml b/app/src/main/res/values-zh-rHK/strings.xml
index a45726e3..39643f57 100644
--- a/app/src/main/res/values-zh-rHK/strings.xml
+++ b/app/src/main/res/values-zh-rHK/strings.xml
@@ -177,12 +177,12 @@
高度超限: 模板圖像 [%1$d] > 限定區域 [%2$d]
寬度超限: 模板圖像 [%1$d] > 限定區域 [%2$d]
應用當前歷史顏色失敗
- 調用方法 \"%s\" 失敗
-
+ 方法 \"%s\" 調用失敗
+
無法將值 %s 轉換為 Drawable 實例
Shizuku 權限授予失敗
- 創建實例 \"%s\" 失敗
-
+ 實例 \"%s\" 創建失敗
+
方法 %1$s 調用失敗
內容渲染失敗
獲取版本信息失敗
@@ -1044,5 +1044,6 @@
未找到用於查看該文件的應用
未找到用於發送該文件的應用
未找到用於播放該文件的應用
+ WebP-Lossless 格式無法使用 quality 質量參數進行壓縮, 可改用 JPEG/PNG/WebP-Lossy
diff --git a/app/src/main/res/values-zh-rTW/strings.xml b/app/src/main/res/values-zh-rTW/strings.xml
index d2929922..fc6d1499 100644
--- a/app/src/main/res/values-zh-rTW/strings.xml
+++ b/app/src/main/res/values-zh-rTW/strings.xml
@@ -177,12 +177,12 @@
高度超限: 模板影象 [%1$d] > 限定區域 [%2$d]
寬度超限: 模板影象 [%1$d] > 限定區域 [%2$d]
應用當前歷史顏色失敗
- 呼叫方法 \"%s\" 失敗
-
+ 方法 \"%s\" 呼叫失敗
+
無法將值 %s 轉換為 Drawable 例項
Shizuku 許可權授予失敗
- 建立例項 \"%s\" 失敗
-
+ 例項 \"%s\" 建立失敗
+
方法 %1$s 呼叫失敗
內容渲染失敗
獲取版本資訊失敗
@@ -1044,5 +1044,6 @@
未找到用於檢視該檔案的應用
未找到用於傳送該檔案的應用
未找到用於播放該檔案的應用
+ WebP-Lossless 格式無法使用 quality 質量引數進行壓縮, 可改用 JPEG/PNG/WebP-Lossy
diff --git a/app/src/main/res/values-zh/strings.xml b/app/src/main/res/values-zh/strings.xml
index 994f0d3a..49e916a5 100644
--- a/app/src/main/res/values-zh/strings.xml
+++ b/app/src/main/res/values-zh/strings.xml
@@ -177,12 +177,12 @@
高度超限: 模板图像 [%1$d] > 限定区域 [%2$d]
宽度超限: 模板图像 [%1$d] > 限定区域 [%2$d]
应用当前历史颜色失败
- 调用方法 \"%s\" 失败
-
+ 方法 \"%s\" 调用失败
+
无法将值 %s 转换为 Drawable 实例
Shizuku 权限授予失败
- 创建实例 \"%s\" 失败
-
+ 实例 \"%s\" 创建失败
+
方法 %1$s 调用失败
内容渲染失败
获取版本信息失败
@@ -1044,5 +1044,6 @@
未找到用于查看该文件的应用
未找到用于发送该文件的应用
未找到用于播放该文件的应用
+ WebP-Lossless 格式无法使用 quality 质量参数进行压缩, 可改用 JPEG/PNG/WebP-Lossy
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index ca5f1d15..2301a1ea 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -1274,5 +1274,6 @@
No applications available for viewing this file
No applications available for sending this file
No applications available for playing this file
+ Format WebP-Lossless cannot be compressed with a quality parameter, use JPEG/PNG/WebP-Lossy instead
diff --git a/libs/imagequant/.gitignore b/libs/imagequant/.gitignore
new file mode 100644
index 00000000..ea2abe7e
--- /dev/null
+++ b/libs/imagequant/.gitignore
@@ -0,0 +1,6 @@
+/build/
+/.cxx/
+/.idea/
+/cache/
+
+/src/sdk/native/
\ No newline at end of file
diff --git a/libs/imagequant/CMakeLists.txt b/libs/imagequant/CMakeLists.txt
new file mode 100644
index 00000000..4439fa60
--- /dev/null
+++ b/libs/imagequant/CMakeLists.txt
@@ -0,0 +1,32 @@
+cmake_minimum_required(VERSION 3.22)
+project(pngquant_bridge LANGUAGES C CXX)
+
+set(CMAKE_C_STANDARD 99)
+
+# --- 1. zlib（NDK 自带） ---
+find_library(ZLIB_LIB z) # libz.so
+
+# --- 2. libpng ---
+add_subdirectory(external/libpng) # 会生成 libpng_static.a
+# libpng 自己就会寻找 zlib
+
+# --- 3. libimagequant ---
+file(GLOB LIQ_SRC
+ "external/libimagequant/*.c")
+add_library(imagequant STATIC ${LIQ_SRC})
+target_include_directories(imagequant PUBLIC
+ external/libimagequant)
+
+# --- 4. 你的 JNI Bridge ---
+add_library(pngquant_bridge SHARED
+ PngQuantBridge.cpp)
+
+target_include_directories(pngquant_bridge PRIVATE
+ external/libimagequant
+ external/libpng)
+
+target_link_libraries(pngquant_bridge
+ imagequant # libimagequant 静态库
+ png_static # libpng 静态库
+ ${ZLIB_LIB} # zlib.so
+ log) # __android_log_print
\ No newline at end of file
diff --git a/libs/imagequant/PngQuantBridge.cpp b/libs/imagequant/PngQuantBridge.cpp
new file mode 100644
index 00000000..35a3501d
--- /dev/null
+++ b/libs/imagequant/PngQuantBridge.cpp
@@ -0,0 +1,159 @@
+#include
+#include
+#include "libimagequant.h"
+#include "png.h"
+#include
+
+#define ALOGE(fmt, ...) __android_log_print(ANDROID_LOG_ERROR, "PNGQ", fmt, ##__VA_ARGS__)
+
+extern "C"
+JNIEXPORT jbyteArray JNICALL
+Java_org_autojs_autojs_runtime_api_PngQuantBridge_quantize(
+ JNIEnv *env, jclass, jbyteArray srcRgba,
+ jint width, jint height, jint quality) {
+
+ /* 读取像素. */
+
+ jsize len = env->GetArrayLength(srcRgba);
+ std::vector rgba(len);
+ env->GetByteArrayRegion(srcRgba, 0, len, reinterpret_cast(rgba.data()));
+
+ if (len != width * height * 4) {
+ ALOGE("rgba length mismatch, len=%d, expect=%d", len, width * height * 4);
+ return nullptr;
+ }
+
+ /* libimagequant 量化. */
+
+ liq_attr *attr = liq_attr_create();
+ if (!attr) {
+ ALOGE("liq_attr_create failed");
+ return nullptr;
+ }
+
+ liq_set_speed(attr, 8);
+ liq_set_quality(attr, quality, quality);
+ liq_set_max_colors(attr, 256);
+
+ liq_image *image = liq_image_create_rgba(attr, rgba.data(), width, height, 0);
+ liq_result *res;
+
+ liq_error err = liq_image_quantize(image, attr, &res);
+ if (err != LIQ_OK) {
+ ALOGE("liq_image_quantize failed, code=%d", err);
+ liq_image_destroy(image);
+ liq_attr_destroy(attr);
+ return nullptr;
+ }
+
+ size_t outSize = width * height;
+ std::vector indexed(outSize);
+ liq_write_remapped_image(res, image, indexed.data(), outSize);
+ const liq_palette *pal = liq_get_palette(res);
+
+ /* 写索引色 PNG 到内存. */
+
+ std::vector compressed;
+ do {
+ /* palette 检查. */
+ if (!pal || pal->count == 0 || pal->count > 256) {
+ ALOGE("invalid palette count=%d", pal ? pal->count : -1);
+ goto png_fail;
+ }
+
+ /* libpng 结构体. */
+ png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
+ nullptr,
+ [](png_structp png_ptr, png_const_charp msg) {
+ ALOGE("libpng error: %s", msg);
+ longjmp(png_jmpbuf(png_ptr), 1);
+ },
+ nullptr);
+ if (!png_ptr) {
+ ALOGE("png_create_write_struct failed");
+ goto png_fail;
+ }
+
+ png_infop info_ptr = png_create_info_struct(png_ptr);
+ if (!info_ptr) {
+ png_destroy_write_struct(&png_ptr, nullptr);
+ goto png_fail;
+ }
+
+ /* longjmp error handler. */
+ if (setjmp(png_jmpbuf(png_ptr))) {
+ png_destroy_write_struct(&png_ptr, &info_ptr);
+ goto png_fail;
+ }
+
+ /* custom mem writer. */
+ struct Writer {
+ static void PNGAPI write(png_structp png_ptr, png_bytep data, png_size_t len) {
+ auto *vec = static_cast *>(png_get_io_ptr(png_ptr));
+ vec->insert(vec->end(), data, data + len);
+ }
+ static void PNGAPI flush(png_structp) {}
+ };
+ std::vector tmpBuf;
+ png_set_write_fn(png_ptr, &tmpBuf, Writer::write, Writer::flush);
+
+ /* IHDR. */
+ png_set_IHDR(png_ptr, info_ptr,
+ static_cast(width),
+ static_cast(height),
+ 8, // bit depth
+ PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE,
+ PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+
+ png_set_compression_level(png_ptr, 3);
+ png_set_filter(png_ptr, 0, PNG_FILTER_NONE);
+
+ /* PLTE & tRNS. */
+ png_color plte[256];
+ png_byte trns[256];
+ int num_trns = 0;
+ for (int i = 0; i < pal->count; ++i) {
+ plte[i].red = pal->entries[i].r;
+ plte[i].green = pal->entries[i].g;
+ plte[i].blue = pal->entries[i].b;
+ trns[i] = pal->entries[i].a;
+ if (trns[i] < 255) num_trns = i + 1;
+ }
+ png_set_PLTE(png_ptr, info_ptr, plte, pal->count);
+ if (num_trns) png_set_tRNS(png_ptr, info_ptr, trns, num_trns, nullptr);
+
+ png_write_info(png_ptr, info_ptr);
+
+ /* rows. */
+ std::vector rows(height);
+ for (int y = 0; y < height; ++y) {
+ rows[y] = indexed.data() + y * width;
+ }
+ png_write_image(png_ptr, rows.data());
+
+ png_write_end(png_ptr, info_ptr);
+ compressed.swap(tmpBuf);
+
+ /* 无论是否成功, 均销毁. */
+ png_destroy_write_struct(&png_ptr, &info_ptr);
+ } while (false);
+
+png_fail:
+ if (compressed.empty()) {
+ ALOGE("compress failed, return null to Java");
+ env->ThrowNew(env->FindClass("java/io/IOException"),
+ "pngquant native: compress failed");
+ return nullptr;
+ }
+
+ /* 清理. */
+ liq_result_destroy(res);
+ liq_image_destroy(image);
+ liq_attr_destroy(attr);
+
+ /* 回 JNI. */
+ jbyteArray out = env->NewByteArray(compressed.size());
+ env->SetByteArrayRegion(out, 0, compressed.size(),
+ reinterpret_cast(compressed.data()));
+ return out;
+}
\ No newline at end of file
diff --git a/libs/imagequant/build.gradle b/libs/imagequant/build.gradle
new file mode 100644
index 00000000..eb220102
--- /dev/null
+++ b/libs/imagequant/build.gradle
@@ -0,0 +1,89 @@
+apply plugin: 'com.android.library'
+apply plugin: 'org.jetbrains.kotlin.android'
+apply from: '../utils.build.gradle'
+
+ext {
+ projectName = "Image Quantization"
+}
+
+def versions = Utils.newVersions(project)
+
+def versionMap = [
+ "libimagequant": "2.17.0",
+ "libpng" : "1.6.49",
+
+ "MIN_SDK" : versions["MIN_SDK"] as Integer,
+ "COMPILE_SDK" : versions["COMPILE_SDK"] as Integer,
+ "TARGET_SDK" : versions["TARGET_SDK"] as Integer,
+
+ "NDK" : versions["IMAGE_QUANT/NDK"],
+ "CMAKE" : versions["IMAGE_QUANT/CMAKE"],
+]
+
+def nameMap = [
+ "PROJECT": ext["projectName"],
+ "NDK" : "NDK",
+ "CMAKE" : "Cmake",
+]
+
+android {
+
+ namespace = "org.pngquant"
+
+ ndkVersion versionMap.NDK
+ compileSdk versionMap.COMPILE_SDK
+
+ defaultConfig {
+ minSdk versionMap.MIN_SDK
+ targetSdk versionMap.TARGET_SDK
+
+ externalNativeBuild {
+ cmake {
+ cppFlags "-std=c++17"
+ }
+ }
+
+ ndk {
+ abiFilters "armeabi-v7a", "arm64-v8a", "x86", "x86_64"
+ }
+ }
+
+ buildTypes {
+ release {
+ minifyEnabled false
+ proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+ }
+ }
+
+ compileOptions {
+ sourceCompatibility = JavaVersion.toVersion(project.ext.javaVersion)
+ targetCompatibility = JavaVersion.toVersion(project.ext.javaVersion)
+ }
+
+ kotlinOptions {
+ jvmTarget = project.ext.javaVersion
+ }
+
+ externalNativeBuild {
+ cmake {
+ path "CMakeLists.txt"
+ version versionMap.CMAKE
+ }
+ }
+}
+
+clean.doFirst {
+ delete project.layout.buildDirectory
+ ['.cxx'].forEach { delete file(it) }
+}
+
+gradle.taskGraph.whenReady { taskGraph ->
+ if (taskGraph.allTasks.any { it.name == "clean" }) return
+
+ Utils.newFormatted("Version information for ${nameMap.PROJECT} Library", [
+ "libimagequant",
+ "libpng",
+ "NDK",
+ "CMAKE",
+ ].collect { "${nameMap[it] ?: it}: ${versionMap[it]}" }).print()
+}
\ No newline at end of file
diff --git a/libs/imagequant/external/libimagequant/.gitignore b/libs/imagequant/external/libimagequant/.gitignore
new file mode 100644
index 00000000..85511949
--- /dev/null
+++ b/libs/imagequant/external/libimagequant/.gitignore
@@ -0,0 +1,27 @@
+config.mk
+imagequant.pc
+*.lo
+*.o
+*.a
+*.so.0
+*.so
+*.bz2
+*.dylib
+*.dylib.0
+*.jnilib
+*.dSYM
+org/pngquant/*.class
+org/pngquant/*.h
+target/
+msvc-dist/org/
+msvc-dist/*.md
+msvc-dist/Makefile*
+msvc-dist/*.cs
+msvc-dist/*.xml
+msvc-dist/CHANGELOG
+msvc-dist/COPYRIGHT
+msvc-dist/configure
+msvc-dist/.gitignore
+quantized_example.png
+example
+lodepng.?
diff --git a/libs/imagequant/external/libimagequant/CMakeLists.txt b/libs/imagequant/external/libimagequant/CMakeLists.txt
new file mode 100644
index 00000000..d14f058d
--- /dev/null
+++ b/libs/imagequant/external/libimagequant/CMakeLists.txt
@@ -0,0 +1,56 @@
+cmake_minimum_required(VERSION 2.6)
+file(READ version.txt VERSION)
+
+project(imagequant C)
+
+if(${CMAKE_SYSTEM_PROCESSOR} STREQUAL ARM64)
+ option(BUILD_WITH_SSE "Use SSE" OFF)
+else()
+ option(BUILD_WITH_SSE "Use SSE" ON)
+endif()
+
+if(BUILD_WITH_SSE)
+ add_definitions(-DUSE_SSE=1)
+endif()
+
+find_package(OpenMP)
+if(OPENMP_FOUND)
+ set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${OpenMP_C_FLAGS}")
+ set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS}")
+endif()
+
+include_directories(${CMAKE_SOURCE_DIR})
+
+if(CMAKE_COMPILER_IS_GNUCC)
+ add_compile_options("-std=c99")
+endif()
+
+add_library(imagequant SHARED
+ libimagequant.c
+ blur.c
+ mediancut.c
+ mempool.c
+ nearest.c
+ pam.c
+ kmeans.c
+)
+
+add_library(imagequant_a STATIC
+ libimagequant.c
+ blur.c
+ mediancut.c
+ mempool.c
+ nearest.c
+ pam.c
+ kmeans.c
+)
+set_target_properties(imagequant PROPERTIES SOVERSION 0
+ VERSION 0.0)
+
+set(PREFIX ${CMAKE_INSTALL_PREFIX})
+configure_file(imagequant.pc.in imagequant.pc @ONLY)
+
+install(TARGETS imagequant LIBRARY DESTINATION ${LIB_INSTALL_DIR})
+install(FILES libimagequant.h DESTINATION include)
+install(FILES ${CMAKE_BINARY_DIR}/libimagequant_a.a DESTINATION ${LIB_INSTALL_DIR} RENAME libimagequant.a)
+install(FILES ${CMAKE_BINARY_DIR}/imagequant.pc DESTINATION ${LIB_INSTALL_DIR}/pkgconfig)
diff --git a/libs/imagequant/external/libimagequant/COPYRIGHT b/libs/imagequant/external/libimagequant/COPYRIGHT
new file mode 100644
index 00000000..4297b943
--- /dev/null
+++ b/libs/imagequant/external/libimagequant/COPYRIGHT
@@ -0,0 +1,641 @@
+
+libimagequant is derived from code by Jef Poskanzer and Greg Roelofs
+licensed under pngquant's original license (at the end of this file),
+and contains extensive changes and additions by Kornel Lesiński
+licensed under GPL v3 or later.
+
+- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+libimagequant © 2009-2018 by Kornel Lesiński.
+
+ GNU GENERAL PUBLIC LICENSE
+ Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc.
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+ Preamble
+
+ The GNU General Public License is a free, copyleft license for
+software and other kinds of works.
+
+ The licenses for most software and other practical works are designed
+to take away your freedom to share and change the works. By contrast,
+the GNU General Public License is intended to guarantee your freedom to
+share and change all versions of a program--to make sure it remains free
+software for all its users. We, the Free Software Foundation, use the
+GNU General Public License for most of our software; it applies also to
+any other work released this way by its authors. You can apply it to
+your programs, too.
+
+ When we speak of free software, we are referring to freedom, not
+price. Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+them if you wish), that you receive source code or can get it if you
+want it, that you can change the software or use pieces of it in new
+free programs, and that you know you can do these things.
+
+ To protect your rights, we need to prevent others from denying you
+these rights or asking you to surrender the rights. Therefore, you have
+certain responsibilities if you distribute copies of the software, or if
+you modify it: responsibilities to respect the freedom of others.
+
+ For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must pass on to the recipients the same
+freedoms that you received. You must make sure that they, too, receive
+or can get the source code. And you must show them these terms so they
+know their rights.
+
+ Developers that use the GNU GPL protect your rights with two steps:
+(1) assert copyright on the software, and (2) offer you this License
+giving you legal permission to copy, distribute and/or modify it.
+
+ For the developers' and authors' protection, the GPL clearly explains
+that there is no warranty for this free software. For both users' and
+authors' sake, the GPL requires that modified versions be marked as
+changed, so that their problems will not be attributed erroneously to
+authors of previous versions.
+
+ Some devices are designed to deny users access to install or run
+modified versions of the software inside them, although the manufacturer
+can do so. This is fundamentally incompatible with the aim of
+protecting users' freedom to change the software. The systematic
+pattern of such abuse occurs in the area of products for individuals to
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+have designed this version of the GPL to prohibit the practice for those
+products. If such problems arise substantially in other domains, we
+stand ready to extend this provision to those domains in future versions
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+
+ Finally, every program is threatened constantly by software patents.
+States should not allow patents to restrict development and use of
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+patents cannot be used to render the program non-free.
+
+ The precise terms and conditions for copying, distribution and
+modification follow.
+
+ TERMS AND CONDITIONS
+
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+ "This License" refers to version 3 of the GNU General Public License.
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+ A "covered work" means either the unmodified Program or a work based
+on the Program.
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+permission, would make you directly or secondarily liable for
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+works, which are not by their nature extensions of the covered work,
+and which are not combined with it such as to form a larger program,
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+used to limit the access or legal rights of the compilation's users
+beyond what the individual works permit. Inclusion of a covered work
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+ 6. Conveying Non-Source Forms.
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+of sections 4 and 5, provided that you also convey the
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+implied warranty.
diff --git a/libs/imagequant/external/libimagequant/blur.c b/libs/imagequant/external/libimagequant/blur.c
new file mode 100644
index 00000000..7f0a7167
--- /dev/null
+++ b/libs/imagequant/external/libimagequant/blur.c
@@ -0,0 +1,132 @@
+/*
+© 2011-2015 by Kornel Lesiński.
+
+This file is part of libimagequant.
+
+libimagequant is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+libimagequant is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with libimagequant. If not, see .
+*/
+
+#include "libimagequant.h"
+#include "pam.h"
+#include "blur.h"
+
+/*
+ Blurs image horizontally (width 2*size+1) and writes it transposed to dst (called twice gives 2d blur)
+ */
+static void transposing_1d_blur(unsigned char *restrict src, unsigned char *restrict dst, unsigned int width, unsigned int height, const unsigned int size)
+{
+ assert(size > 0);
+
+ for(unsigned int j=0; j < height; j++) {
+ unsigned char *restrict row = src + j*width;
+
+ // accumulate sum for pixels outside line
+ unsigned int sum;
+ sum = row[0]*size;
+ for(unsigned int i=0; i < size; i++) {
+ sum += row[i];
+ }
+
+ // blur with left side outside line
+ for(unsigned int i=0; i < size; i++) {
+ sum -= row[0];
+ sum += row[i+size];
+
+ dst[i*height + j] = sum / (size*2);
+ }
+
+ for(unsigned int i=size; i < width-size; i++) {
+ sum -= row[i-size];
+ sum += row[i+size];
+
+ dst[i*height + j] = sum / (size*2);
+ }
+
+ // blur with right side outside line
+ for(unsigned int i=width-size; i < width; i++) {
+ sum -= row[i-size];
+ sum += row[width-1];
+
+ dst[i*height + j] = sum / (size*2);
+ }
+ }
+}
+
+/**
+ * Picks maximum of neighboring pixels (blur + lighten)
+ */
+LIQ_PRIVATE void liq_max3(unsigned char *src, unsigned char *dst, unsigned int width, unsigned int height)
+{
+ for(unsigned int j=0; j < height; j++) {
+ const unsigned char *row = src + j*width,
+ *prevrow = src + (j > 1 ? j-1 : 0)*width,
+ *nextrow = src + MIN(height-1,j+1)*width;
+
+ unsigned char prev,curr=row[0],next=row[0];
+
+ for(unsigned int i=0; i < width-1; i++) {
+ prev=curr;
+ curr=next;
+ next=row[i+1];
+
+ unsigned char t1 = MAX(prev,next);
+ unsigned char t2 = MAX(nextrow[i],prevrow[i]);
+ *dst++ = MAX(curr,MAX(t1,t2));
+ }
+ unsigned char t1 = MAX(curr,next);
+ unsigned char t2 = MAX(nextrow[width-1],prevrow[width-1]);
+ *dst++ = MAX(t1,t2);
+ }
+}
+
+/**
+ * Picks minimum of neighboring pixels (blur + darken)
+ */
+LIQ_PRIVATE void liq_min3(unsigned char *src, unsigned char *dst, unsigned int width, unsigned int height)
+{
+ for(unsigned int j=0; j < height; j++) {
+ const unsigned char *row = src + j*width,
+ *prevrow = src + (j > 1 ? j-1 : 0)*width,
+ *nextrow = src + MIN(height-1,j+1)*width;
+
+ unsigned char prev,curr=row[0],next=row[0];
+
+ for(unsigned int i=0; i < width-1; i++) {
+ prev=curr;
+ curr=next;
+ next=row[i+1];
+
+ unsigned char t1 = MIN(prev,next);
+ unsigned char t2 = MIN(nextrow[i],prevrow[i]);
+ *dst++ = MIN(curr,MIN(t1,t2));
+ }
+ unsigned char t1 = MIN(curr,next);
+ unsigned char t2 = MIN(nextrow[width-1],prevrow[width-1]);
+ *dst++ = MIN(t1,t2);
+ }
+}
+
+/*
+ Filters src image and saves it to dst, overwriting tmp in the process.
+ Image must be width*height pixels high. Size controls radius of box blur.
+ */
+LIQ_PRIVATE void liq_blur(unsigned char *src, unsigned char *tmp, unsigned char *dst, unsigned int width, unsigned int height, unsigned int size)
+{
+ assert(size > 0);
+ if (width < 2*size+1 || height < 2*size+1) {
+ return;
+ }
+ transposing_1d_blur(src, tmp, width, height, size);
+ transposing_1d_blur(tmp, dst, height, width, size);
+}
diff --git a/libs/imagequant/external/libimagequant/blur.h b/libs/imagequant/external/libimagequant/blur.h
new file mode 100644
index 00000000..1e778192
--- /dev/null
+++ b/libs/imagequant/external/libimagequant/blur.h
@@ -0,0 +1,8 @@
+#ifndef BLUR_H
+#define BLUR_H
+
+LIQ_PRIVATE void liq_blur(unsigned char *src, unsigned char *tmp, unsigned char *dst, unsigned int width, unsigned int height, unsigned int size);
+LIQ_PRIVATE void liq_max3(unsigned char *src, unsigned char *dst, unsigned int width, unsigned int height);
+LIQ_PRIVATE void liq_min3(unsigned char *src, unsigned char *dst, unsigned int width, unsigned int height);
+
+#endif
diff --git a/libs/imagequant/external/libimagequant/example.c b/libs/imagequant/external/libimagequant/example.c
new file mode 100644
index 00000000..355a92b5
--- /dev/null
+++ b/libs/imagequant/external/libimagequant/example.c
@@ -0,0 +1,115 @@
+/**
+
+This is an example how to write your own simple pngquant using libimagequant.
+
+libimagequant works with any PNG library. This example uses lodepng, because it's easier to use than libpng.
+
+To run this example, run these commands in the library directory:
+
+ make example
+ ./example /path/to/some_file.png
+
+On "manually":
+
+1. Get lodepng.c (download lodepng.cpp and rename it) and lodepng.h
+ from http://lodev.org/lodepng/ and put them in this directry
+
+2. Compile libimagequant (see README.md)
+
+3. Compile and run the example:
+
+ gcc -O3 example.c libimagequant.a -o example
+ ./example truecolor_file.png
+
+
+This example code can be freely copied under CC0 (public domain) license.
+*/
+
+#include "lodepng.h" // Get it from https://raw.githubusercontent.com/lvandeve/lodepng/master/lodepng.h
+#include "lodepng.c" // Get it from https://raw.githubusercontent.com/lvandeve/lodepng/master/lodepng.cpp and rename
+#include
+#include
+#include "libimagequant.h"
+
+int main(int argc, char *argv[]) {
+ if (argc < 2) {
+ fprintf(stderr, "Please specify a path to a PNG file\n");
+ return EXIT_FAILURE;
+ }
+
+ const char *input_png_file_path = argv[1];
+
+ // Load PNG file and decode it as raw RGBA pixels
+ // This uses lodepng library for PNG reading (not part of libimagequant)
+
+ unsigned int width, height;
+ unsigned char *raw_rgba_pixels;
+ unsigned int status = lodepng_decode32_file(&raw_rgba_pixels, &width, &height, input_png_file_path);
+ if (status) {
+ fprintf(stderr, "Can't load %s: %s\n", input_png_file_path, lodepng_error_text(status));
+ return EXIT_FAILURE;
+ }
+
+ // Use libimagequant to make a palette for the RGBA pixels
+
+ liq_attr *handle = liq_attr_create();
+ liq_image *input_image = liq_image_create_rgba(handle, raw_rgba_pixels, width, height, 0);
+ // You could set more options here, like liq_set_quality
+ liq_result *quantization_result;
+ if (liq_image_quantize(input_image, handle, &quantization_result) != LIQ_OK) {
+ fprintf(stderr, "Quantization failed\n");
+ return EXIT_FAILURE;
+ }
+
+ // Use libimagequant to make new image pixels from the palette
+
+ size_t pixels_size = width * height;
+ unsigned char *raw_8bit_pixels = malloc(pixels_size);
+ liq_set_dithering_level(quantization_result, 1.0);
+
+ liq_write_remapped_image(quantization_result, input_image, raw_8bit_pixels, pixels_size);
+ const liq_palette *palette = liq_get_palette(quantization_result);
+
+ // Save converted pixels as a PNG file
+ // This uses lodepng library for PNG writing (not part of libimagequant)
+
+ LodePNGState state;
+ lodepng_state_init(&state);
+ state.info_raw.colortype = LCT_PALETTE;
+ state.info_raw.bitdepth = 8;
+ state.info_png.color.colortype = LCT_PALETTE;
+ state.info_png.color.bitdepth = 8;
+
+ for(int i=0; i < palette->count; i++) {
+ lodepng_palette_add(&state.info_png.color, palette->entries[i].r, palette->entries[i].g, palette->entries[i].b, palette->entries[i].a);
+ lodepng_palette_add(&state.info_raw, palette->entries[i].r, palette->entries[i].g, palette->entries[i].b, palette->entries[i].a);
+ }
+
+ unsigned char *output_file_data;
+ size_t output_file_size;
+ unsigned int out_status = lodepng_encode(&output_file_data, &output_file_size, raw_8bit_pixels, width, height, &state);
+ if (out_status) {
+ fprintf(stderr, "Can't encode image: %s\n", lodepng_error_text(out_status));
+ return EXIT_FAILURE;
+ }
+
+ const char *output_png_file_path = "quantized_example.png";
+ FILE *fp = fopen(output_png_file_path, "wb");
+ if (!fp) {
+ fprintf(stderr, "Unable to write to %s\n", output_png_file_path);
+ return EXIT_FAILURE;
+ }
+ fwrite(output_file_data, 1, output_file_size, fp);
+ fclose(fp);
+
+ printf("Written %s\n", output_png_file_path);
+
+ // Done. Free memory.
+
+ liq_result_destroy(quantization_result); // Must be freed only after you're done using the palette
+ liq_image_destroy(input_image);
+ liq_attr_destroy(handle);
+
+ free(raw_8bit_pixels);
+ lodepng_state_cleanup(&state);
+}
diff --git a/libs/imagequant/external/libimagequant/kmeans.c b/libs/imagequant/external/libimagequant/kmeans.c
new file mode 100644
index 00000000..3373f90b
--- /dev/null
+++ b/libs/imagequant/external/libimagequant/kmeans.c
@@ -0,0 +1,120 @@
+/*
+** © 2011-2016 by Kornel Lesiński.
+** See COPYRIGHT file for license.
+*/
+
+#include "libimagequant.h"
+#include "pam.h"
+#include "kmeans.h"
+#include "nearest.h"
+#include
+#include
+
+#ifdef _OPENMP
+#include
+#else
+#define omp_get_max_threads() 1
+#define omp_get_thread_num() 0
+#endif
+
+/*
+ * K-Means iteration: new palette color is computed from weighted average of colors that map to that palette entry.
+ */
+LIQ_PRIVATE void kmeans_init(const colormap *map, const unsigned int max_threads, kmeans_state average_color[])
+{
+ memset(average_color, 0, sizeof(average_color[0])*(KMEANS_CACHE_LINE_GAP+map->colors)*max_threads);
+}
+
+LIQ_PRIVATE void kmeans_update_color(const f_pixel acolor, const float value, const colormap *map, unsigned int match, const unsigned int thread, kmeans_state average_color[])
+{
+ match += thread * (KMEANS_CACHE_LINE_GAP+map->colors);
+ average_color[match].a += acolor.a * value;
+ average_color[match].r += acolor.r * value;
+ average_color[match].g += acolor.g * value;
+ average_color[match].b += acolor.b * value;
+ average_color[match].total += value;
+}
+
+LIQ_PRIVATE void kmeans_finalize(colormap *map, const unsigned int max_threads, const kmeans_state average_color[])
+{
+ for (unsigned int i=0; i < map->colors; i++) {
+ double a=0, r=0, g=0, b=0, total=0;
+
+ // Aggregate results from all threads
+ for(unsigned int t=0; t < max_threads; t++) {
+ const unsigned int offset = (KMEANS_CACHE_LINE_GAP+map->colors) * t + i;
+
+ a += average_color[offset].a;
+ r += average_color[offset].r;
+ g += average_color[offset].g;
+ b += average_color[offset].b;
+ total += average_color[offset].total;
+ }
+
+ if (!map->palette[i].fixed) {
+ map->palette[i].popularity = total;
+ if (total) {
+ map->palette[i].acolor = (f_pixel){
+ .a = a / total,
+ .r = r / total,
+ .g = g / total,
+ .b = b / total,
+ };
+ } else {
+ // if a color is useless, make a new one
+ // (it was supposed to be random, but Android NDK has problematic stdlib headers)
+ map->palette[i].acolor.a = map->palette[(i+1)%map->colors].acolor.a;
+ map->palette[i].acolor.r = map->palette[(i+2)%map->colors].acolor.r;
+ map->palette[i].acolor.g = map->palette[(i+3)%map->colors].acolor.g;
+ map->palette[i].acolor.b = map->palette[(i+4)%map->colors].acolor.b;
+ }
+ }
+ }
+}
+
+LIQ_PRIVATE double kmeans_do_iteration(histogram *hist, colormap *const map, kmeans_callback callback)
+{
+ const unsigned int max_threads = omp_get_max_threads();
+ LIQ_ARRAY(kmeans_state, average_color, (KMEANS_CACHE_LINE_GAP+map->colors) * max_threads);
+ kmeans_init(map, max_threads, average_color);
+ struct nearest_map *const n = nearest_init(map);
+ hist_item *const achv = hist->achv;
+ const int hist_size = hist->size;
+
+ double total_diff=0;
+#if __GNUC__ >= 9 || __clang__
+ #pragma omp parallel for if (hist_size > 2000) \
+ schedule(static) default(none) shared(achv,average_color,callback,hist_size,map,n) reduction(+:total_diff)
+#else
+ #pragma omp parallel for if (hist_size > 2000) \
+ schedule(static) default(none) shared(average_color,callback) reduction(+:total_diff)
+#endif
+ for(int j=0; j < hist_size; j++) {
+ float diff;
+ const f_pixel px = achv[j].acolor;
+ const unsigned int match = nearest_search(n, &px, achv[j].tmp.likely_colormap_index, &diff);
+ achv[j].tmp.likely_colormap_index = match;
+
+ if (callback) {
+ // Check how average diff would look like if there was dithering
+ const f_pixel remapped = map->palette[match].acolor;
+ nearest_search(n, &(f_pixel){
+ .a = px.a + px.a - remapped.a,
+ .r = px.r + px.r - remapped.r,
+ .g = px.g + px.g - remapped.g,
+ .b = px.b + px.b - remapped.b,
+ }, match, &diff);
+
+ callback(&achv[j], diff);
+ }
+
+ total_diff += diff * achv[j].perceptual_weight;
+
+ kmeans_update_color(px, achv[j].adjusted_weight, map, match, omp_get_thread_num(), average_color);
+ }
+
+ nearest_free(n);
+ kmeans_finalize(map, max_threads, average_color);
+
+ return total_diff / hist->total_perceptual_weight;
+}
diff --git a/libs/imagequant/external/libimagequant/kmeans.h b/libs/imagequant/external/libimagequant/kmeans.h
new file mode 100644
index 00000000..c51d7bbd
--- /dev/null
+++ b/libs/imagequant/external/libimagequant/kmeans.h
@@ -0,0 +1,19 @@
+
+#ifndef KMEANS_H
+#define KMEANS_H
+
+// Spread memory touched by different threads at least 64B apart which I assume is the cache line size. This should avoid memory write contention.
+#define KMEANS_CACHE_LINE_GAP ((64+sizeof(kmeans_state)-1)/sizeof(kmeans_state))
+
+typedef struct {
+ double a, r, g, b, total;
+} kmeans_state;
+
+typedef void (*kmeans_callback)(hist_item *item, float diff);
+
+LIQ_PRIVATE void kmeans_init(const colormap *map, const unsigned int max_threads, kmeans_state state[]);
+LIQ_PRIVATE void kmeans_update_color(const f_pixel acolor, const float value, const colormap *map, unsigned int match, const unsigned int thread, kmeans_state average_color[]);
+LIQ_PRIVATE void kmeans_finalize(colormap *map, const unsigned int max_threads, const kmeans_state state[]);
+LIQ_PRIVATE double kmeans_do_iteration(histogram *hist, colormap *const map, kmeans_callback callback);
+
+#endif
diff --git a/libs/imagequant/external/libimagequant/libimagequant.c b/libs/imagequant/external/libimagequant/libimagequant.c
new file mode 100644
index 00000000..a9b37300
--- /dev/null
+++ b/libs/imagequant/external/libimagequant/libimagequant.c
@@ -0,0 +1,2179 @@
+/*
+** © 2009-2018 by Kornel Lesiński.
+** © 1989, 1991 by Jef Poskanzer.
+** © 1997, 2000, 2002 by Greg Roelofs; based on an idea by Stefan Schneider.
+**
+** See COPYRIGHT file for license.
+*/
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#if !(defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199900L) && !(defined(_MSC_VER) && _MSC_VER >= 1800)
+#error "This program requires C99, e.g. -std=c99 switch in GCC or it requires MSVC 18.0 or higher."
+#error "Ignore torrent of syntax errors that may follow. It's only because compiler is set to use too old C version."
+#endif
+
+#ifdef _OPENMP
+#include
+#define LIQ_TEMP_ROW_WIDTH(img_width) (((img_width) | 15) + 1) /* keep alignment & leave space between rows to avoid cache line contention */
+#else
+#define LIQ_TEMP_ROW_WIDTH(img_width) (img_width)
+#define omp_get_max_threads() 1
+#define omp_get_thread_num() 0
+#endif
+
+#include "libimagequant.h"
+
+#include "pam.h"
+#include "mediancut.h"
+#include "nearest.h"
+#include "blur.h"
+#include "kmeans.h"
+
+#define LIQ_HIGH_MEMORY_LIMIT (1<<26) /* avoid allocating buffers larger than 64MB */
+
+// each structure has a pointer as a unique identifier that allows type checking at run time
+static const char liq_attr_magic[] = "liq_attr";
+static const char liq_image_magic[] = "liq_image";
+static const char liq_result_magic[] = "liq_result";
+static const char liq_histogram_magic[] = "liq_histogram";
+static const char liq_remapping_result_magic[] = "liq_remapping_result";
+static const char liq_freed_magic[] = "free";
+#define CHECK_STRUCT_TYPE(attr, kind) liq_crash_if_invalid_handle_pointer_given((const liq_attr*)attr, kind ## _magic)
+#define CHECK_USER_POINTER(ptr) liq_crash_if_invalid_pointer_given(ptr)
+
+struct liq_attr {
+ const char *magic_header;
+ void* (*malloc)(size_t);
+ void (*free)(void*);
+
+ double target_mse, max_mse, kmeans_iteration_limit;
+ unsigned int max_colors, max_histogram_entries;
+ unsigned int min_posterization_output /* user setting */, min_posterization_input /* speed setting */;
+ unsigned int kmeans_iterations, feedback_loop_trials;
+ bool last_index_transparent, use_contrast_maps;
+ unsigned char use_dither_map;
+ unsigned char speed;
+
+ unsigned char progress_stage1, progress_stage2, progress_stage3;
+ liq_progress_callback_function *progress_callback;
+ void *progress_callback_user_info;
+
+ liq_log_callback_function *log_callback;
+ void *log_callback_user_info;
+ liq_log_flush_callback_function *log_flush_callback;
+ void *log_flush_callback_user_info;
+};
+
+struct liq_image {
+ const char *magic_header;
+ void* (*malloc)(size_t);
+ void (*free)(void*);
+
+ f_pixel *f_pixels;
+ rgba_pixel **rows;
+ double gamma;
+ unsigned int width, height;
+ unsigned char *importance_map, *edges, *dither_map;
+ rgba_pixel *pixels, *temp_row;
+ f_pixel *temp_f_row;
+ liq_image_get_rgba_row_callback *row_callback;
+ void *row_callback_user_info;
+ liq_image *background;
+ f_pixel fixed_colors[256];
+ unsigned short fixed_colors_count;
+ bool free_pixels, free_rows, free_rows_internal;
+};
+
+typedef struct liq_remapping_result {
+ const char *magic_header;
+ void* (*malloc)(size_t);
+ void (*free)(void*);
+
+ unsigned char *pixels;
+ colormap *palette;
+ liq_progress_callback_function *progress_callback;
+ void *progress_callback_user_info;
+
+ liq_palette int_palette;
+ double gamma, palette_error;
+ float dither_level;
+ unsigned char use_dither_map;
+ unsigned char progress_stage1;
+} liq_remapping_result;
+
+struct liq_result {
+ const char *magic_header;
+ void* (*malloc)(size_t);
+ void (*free)(void*);
+
+ liq_remapping_result *remapping;
+ colormap *palette;
+ liq_progress_callback_function *progress_callback;
+ void *progress_callback_user_info;
+
+ liq_palette int_palette;
+ float dither_level;
+ double gamma, palette_error;
+ int min_posterization_output;
+ unsigned char use_dither_map;
+};
+
+struct liq_histogram {
+ const char *magic_header;
+ void* (*malloc)(size_t);
+ void (*free)(void*);
+
+ struct acolorhash_table *acht;
+ double gamma;
+ f_pixel fixed_colors[256];
+ unsigned short fixed_colors_count;
+ unsigned short ignorebits;
+ bool had_image_added;
+};
+
+static void contrast_maps(liq_image *image) LIQ_NONNULL;
+static liq_error finalize_histogram(liq_histogram *input_hist, liq_attr *options, histogram **hist_output) LIQ_NONNULL;
+static const rgba_pixel *liq_image_get_row_rgba(liq_image *input_image, unsigned int row) LIQ_NONNULL;
+static bool liq_image_get_row_f_init(liq_image *img) LIQ_NONNULL;
+static const f_pixel *liq_image_get_row_f(liq_image *input_image, unsigned int row) LIQ_NONNULL;
+static void liq_remapping_result_destroy(liq_remapping_result *result) LIQ_NONNULL;
+static liq_error pngquant_quantize(histogram *hist, const liq_attr *options, const int fixed_colors_count, const f_pixel fixed_colors[], const double gamma, bool fixed_result_colors, liq_result **) LIQ_NONNULL;
+static liq_error liq_histogram_quantize_internal(liq_histogram *input_hist, liq_attr *attr, bool fixed_result_colors, liq_result **result_output) LIQ_NONNULL;
+
+LIQ_NONNULL static void liq_verbose_printf(const liq_attr *context, const char *fmt, ...)
+{
+ if (context->log_callback) {
+ va_list va;
+ va_start(va, fmt);
+ int required_space = vsnprintf(NULL, 0, fmt, va)+1; // +\0
+ va_end(va);
+
+ LIQ_ARRAY(char, buf, required_space);
+ va_start(va, fmt);
+ vsnprintf(buf, required_space, fmt, va);
+ va_end(va);
+
+ context->log_callback(context, buf, context->log_callback_user_info);
+ }
+}
+
+LIQ_NONNULL inline static void verbose_print(const liq_attr *attr, const char *msg)
+{
+ if (attr->log_callback) {
+ attr->log_callback(attr, msg, attr->log_callback_user_info);
+ }
+}
+
+LIQ_NONNULL static void liq_verbose_printf_flush(liq_attr *attr)
+{
+ if (attr->log_flush_callback) {
+ attr->log_flush_callback(attr, attr->log_flush_callback_user_info);
+ }
+}
+
+LIQ_NONNULL static bool liq_progress(const liq_attr *attr, const float percent)
+{
+ return attr->progress_callback && !attr->progress_callback(percent, attr->progress_callback_user_info);
+}
+
+LIQ_NONNULL static bool liq_remap_progress(const liq_remapping_result *quant, const float percent)
+{
+ return quant->progress_callback && !quant->progress_callback(percent, quant->progress_callback_user_info);
+}
+
+#if USE_SSE
+inline static bool is_sse_available()
+{
+#if (defined(__x86_64__) || defined(__amd64) || defined(_WIN64))
+ return true;
+#elif _MSC_VER
+ int info[4];
+ __cpuid(info, 1);
+ /* bool is implemented as a built-in type of size 1 in MSVC */
+ return info[3] & (1<<26) ? true : false;
+#else
+ int a,b,c,d;
+ cpuid(1, a, b, c, d);
+ return d & (1<<25); // edx bit 25 is set when SSE is present
+#endif
+}
+#endif
+
+/* make it clear in backtrace when user-supplied handle points to invalid memory */
+NEVER_INLINE LIQ_EXPORT bool liq_crash_if_invalid_handle_pointer_given(const liq_attr *user_supplied_pointer, const char *const expected_magic_header);
+LIQ_EXPORT bool liq_crash_if_invalid_handle_pointer_given(const liq_attr *user_supplied_pointer, const char *const expected_magic_header)
+{
+ if (!user_supplied_pointer) {
+ return false;
+ }
+
+ if (user_supplied_pointer->magic_header == liq_freed_magic) {
+ fprintf(stderr, "%s used after being freed", expected_magic_header);
+ // this is not normal error handling, this is programmer error that should crash the program.
+ // program cannot safely continue if memory has been used after it's been freed.
+ // abort() is nasty, but security vulnerability may be worse.
+ abort();
+ }
+
+ return user_supplied_pointer->magic_header == expected_magic_header;
+}
+
+NEVER_INLINE LIQ_EXPORT bool liq_crash_if_invalid_pointer_given(const void *pointer);
+LIQ_EXPORT bool liq_crash_if_invalid_pointer_given(const void *pointer)
+{
+ if (!pointer) {
+ return false;
+ }
+ // Force a read from the given (potentially invalid) memory location in order to check early whether this crashes the program or not.
+ // It doesn't matter what value is read, the code here is just to shut the compiler up about unused read.
+ char test_access = *((volatile char *)pointer);
+ return test_access || true;
+}
+
+LIQ_NONNULL static void liq_log_error(const liq_attr *attr, const char *msg)
+{
+ if (!CHECK_STRUCT_TYPE(attr, liq_attr)) return;
+ liq_verbose_printf(attr, " error: %s", msg);
+}
+
+static double quality_to_mse(long quality)
+{
+ if (quality == 0) {
+ return MAX_DIFF;
+ }
+ if (quality == 100) {
+ return 0;
+ }
+
+ // curve fudged to be roughly similar to quality of libjpeg
+ // except lowest 10 for really low number of colors
+ const double extra_low_quality_fudge = MAX(0,0.016/(0.001+quality) - 0.001);
+ return extra_low_quality_fudge + 2.5/pow(210.0 + quality, 1.2) * (100.1-quality)/100.0;
+}
+
+static unsigned int mse_to_quality(double mse)
+{
+ for(int i=100; i > 0; i--) {
+ if (mse <= quality_to_mse(i) + 0.000001) { // + epsilon for floating point errors
+ return i;
+ }
+ }
+ return 0;
+}
+
+/** internally MSE is a sum of all channels with pixels 0..1 range,
+ but other software gives per-RGB-channel MSE for 0..255 range */
+static double mse_to_standard_mse(double mse) {
+ return mse * 65536.0/6.0;
+}
+
+LIQ_EXPORT LIQ_NONNULL liq_error liq_set_quality(liq_attr* attr, int minimum, int target)
+{
+ if (!CHECK_STRUCT_TYPE(attr, liq_attr)) return LIQ_INVALID_POINTER;
+ if (target < 0 || target > 100 || target < minimum || minimum < 0) return LIQ_VALUE_OUT_OF_RANGE;
+
+ attr->target_mse = quality_to_mse(target);
+ attr->max_mse = quality_to_mse(minimum);
+ return LIQ_OK;
+}
+
+LIQ_EXPORT LIQ_NONNULL int liq_get_min_quality(const liq_attr *attr)
+{
+ if (!CHECK_STRUCT_TYPE(attr, liq_attr)) return -1;
+ return mse_to_quality(attr->max_mse);
+}
+
+LIQ_EXPORT LIQ_NONNULL int liq_get_max_quality(const liq_attr *attr)
+{
+ if (!CHECK_STRUCT_TYPE(attr, liq_attr)) return -1;
+ return mse_to_quality(attr->target_mse);
+}
+
+
+LIQ_EXPORT LIQ_NONNULL liq_error liq_set_max_colors(liq_attr* attr, int colors)
+{
+ if (!CHECK_STRUCT_TYPE(attr, liq_attr)) return LIQ_INVALID_POINTER;
+ if (colors < 2 || colors > 256) return LIQ_VALUE_OUT_OF_RANGE;
+
+ attr->max_colors = colors;
+ return LIQ_OK;
+}
+
+LIQ_EXPORT LIQ_NONNULL int liq_get_max_colors(const liq_attr *attr)
+{
+ if (!CHECK_STRUCT_TYPE(attr, liq_attr)) return -1;
+
+ return attr->max_colors;
+}
+
+LIQ_EXPORT LIQ_NONNULL liq_error liq_set_min_posterization(liq_attr *attr, int bits)
+{
+ if (!CHECK_STRUCT_TYPE(attr, liq_attr)) return LIQ_INVALID_POINTER;
+ if (bits < 0 || bits > 4) return LIQ_VALUE_OUT_OF_RANGE;
+
+ attr->min_posterization_output = bits;
+ return LIQ_OK;
+}
+
+LIQ_EXPORT LIQ_NONNULL int liq_get_min_posterization(const liq_attr *attr)
+{
+ if (!CHECK_STRUCT_TYPE(attr, liq_attr)) return -1;
+
+ return attr->min_posterization_output;
+}
+
+LIQ_EXPORT LIQ_NONNULL liq_error liq_set_speed(liq_attr* attr, int speed)
+{
+ if (!CHECK_STRUCT_TYPE(attr, liq_attr)) return LIQ_INVALID_POINTER;
+ if (speed < 1 || speed > 10) return LIQ_VALUE_OUT_OF_RANGE;
+
+ unsigned int iterations = MAX(8-speed, 0);
+ iterations += iterations * iterations/2;
+ attr->kmeans_iterations = iterations;
+ attr->kmeans_iteration_limit = 1.0/(double)(1<<(23-speed));
+ attr->feedback_loop_trials = MAX(56-9*speed, 0);
+
+ attr->max_histogram_entries = (1<<17) + (1<<18)*(10-speed);
+ attr->min_posterization_input = (speed >= 8) ? 1 : 0;
+ attr->use_dither_map = (speed <= (omp_get_max_threads() > 1 ? 7 : 5)); // parallelized dither map might speed up floyd remapping
+ if (attr->use_dither_map && speed < 3) {
+ attr->use_dither_map = 2; // always
+ }
+ attr->use_contrast_maps = (speed <= 7) || attr->use_dither_map;
+ attr->speed = speed;
+
+ attr->progress_stage1 = attr->use_contrast_maps ? 20 : 8;
+ if (attr->feedback_loop_trials < 2) {
+ attr->progress_stage1 += 30;
+ }
+ attr->progress_stage3 = 50 / (1+speed);
+ attr->progress_stage2 = 100 - attr->progress_stage1 - attr->progress_stage3;
+ return LIQ_OK;
+}
+
+LIQ_EXPORT LIQ_NONNULL int liq_get_speed(const liq_attr *attr)
+{
+ if (!CHECK_STRUCT_TYPE(attr, liq_attr)) return -1;
+
+ return attr->speed;
+}
+
+LIQ_EXPORT LIQ_NONNULL liq_error liq_set_output_gamma(liq_result* res, double gamma)
+{
+ if (!CHECK_STRUCT_TYPE(res, liq_result)) return LIQ_INVALID_POINTER;
+ if (gamma <= 0 || gamma >= 1.0) return LIQ_VALUE_OUT_OF_RANGE;
+
+ if (res->remapping) {
+ liq_remapping_result_destroy(res->remapping);
+ res->remapping = NULL;
+ }
+
+ res->gamma = gamma;
+ return LIQ_OK;
+}
+
+LIQ_EXPORT LIQ_NONNULL liq_error liq_set_min_opacity(liq_attr* attr, int min)
+{
+ return LIQ_OK;
+}
+
+LIQ_EXPORT LIQ_NONNULL int liq_get_min_opacity(const liq_attr *attr)
+{
+ return 0;
+}
+
+LIQ_EXPORT LIQ_NONNULL void liq_set_last_index_transparent(liq_attr* attr, int is_last)
+{
+ if (!CHECK_STRUCT_TYPE(attr, liq_attr)) return;
+
+ attr->last_index_transparent = !!is_last;
+}
+
+LIQ_EXPORT void liq_attr_set_progress_callback(liq_attr *attr, liq_progress_callback_function *callback, void *user_info)
+{
+ if (!CHECK_STRUCT_TYPE(attr, liq_attr)) return;
+
+ attr->progress_callback = callback;
+ attr->progress_callback_user_info = user_info;
+}
+
+LIQ_EXPORT void liq_result_set_progress_callback(liq_result *result, liq_progress_callback_function *callback, void *user_info)
+{
+ if (!CHECK_STRUCT_TYPE(result, liq_result)) return;
+
+ result->progress_callback = callback;
+ result->progress_callback_user_info = user_info;
+}
+
+LIQ_EXPORT void liq_set_log_callback(liq_attr *attr, liq_log_callback_function *callback, void* user_info)
+{
+ if (!CHECK_STRUCT_TYPE(attr, liq_attr)) return;
+
+ liq_verbose_printf_flush(attr);
+ attr->log_callback = callback;
+ attr->log_callback_user_info = user_info;
+}
+
+LIQ_EXPORT void liq_set_log_flush_callback(liq_attr *attr, liq_log_flush_callback_function *callback, void* user_info)
+{
+ if (!CHECK_STRUCT_TYPE(attr, liq_attr)) return;
+
+ attr->log_flush_callback = callback;
+ attr->log_flush_callback_user_info = user_info;
+}
+
+LIQ_EXPORT liq_attr* liq_attr_create()
+{
+ return liq_attr_create_with_allocator(NULL, NULL);
+}
+
+LIQ_EXPORT LIQ_NONNULL void liq_attr_destroy(liq_attr *attr)
+{
+ if (!CHECK_STRUCT_TYPE(attr, liq_attr)) {
+ return;
+ }
+
+ liq_verbose_printf_flush(attr);
+
+ attr->magic_header = liq_freed_magic;
+ attr->free(attr);
+}
+
+LIQ_EXPORT LIQ_NONNULL liq_attr* liq_attr_copy(const liq_attr *orig)
+{
+ if (!CHECK_STRUCT_TYPE(orig, liq_attr)) {
+ return NULL;
+ }
+
+ liq_attr *attr = orig->malloc(sizeof(liq_attr));
+ if (!attr) return NULL;
+ *attr = *orig;
+ return attr;
+}
+
+static void *liq_aligned_malloc(size_t size)
+{
+ unsigned char *ptr = malloc(size + 16);
+ if (!ptr) {
+ return NULL;
+ }
+
+ uintptr_t offset = 16 - ((uintptr_t)ptr & 15); // also reserves 1 byte for ptr[-1]
+ ptr += offset;
+ assert(0 == (((uintptr_t)ptr) & 15));
+ ptr[-1] = offset ^ 0x59; // store how much pointer was shifted to get the original for free()
+ return ptr;
+}
+
+LIQ_NONNULL static void liq_aligned_free(void *inptr)
+{
+ unsigned char *ptr = inptr;
+ size_t offset = ptr[-1] ^ 0x59;
+ assert(offset > 0 && offset <= 16);
+ free(ptr - offset);
+}
+
+LIQ_EXPORT liq_attr* liq_attr_create_with_allocator(void* (*custom_malloc)(size_t), void (*custom_free)(void*))
+{
+#if USE_SSE
+ if (!is_sse_available()) {
+ return NULL;
+ }
+#endif
+ if (!custom_malloc && !custom_free) {
+ custom_malloc = liq_aligned_malloc;
+ custom_free = liq_aligned_free;
+ } else if (!custom_malloc != !custom_free) {
+ return NULL; // either specify both or none
+ }
+
+ liq_attr *attr = custom_malloc(sizeof(liq_attr));
+ if (!attr) return NULL;
+ *attr = (liq_attr) {
+ .magic_header = liq_attr_magic,
+ .malloc = custom_malloc,
+ .free = custom_free,
+ .max_colors = 256,
+ .last_index_transparent = false, // puts transparent color at last index. This is workaround for blu-ray subtitles.
+ .target_mse = 0,
+ .max_mse = MAX_DIFF,
+ };
+ liq_set_speed(attr, 4);
+ return attr;
+}
+
+LIQ_EXPORT LIQ_NONNULL liq_error liq_image_add_fixed_color(liq_image *img, liq_color color)
+{
+ if (!CHECK_STRUCT_TYPE(img, liq_image)) return LIQ_INVALID_POINTER;
+ if (img->fixed_colors_count > 255) return LIQ_UNSUPPORTED;
+
+ float gamma_lut[256];
+ to_f_set_gamma(gamma_lut, img->gamma);
+ img->fixed_colors[img->fixed_colors_count++] = rgba_to_f(gamma_lut, (rgba_pixel){
+ .r = color.r,
+ .g = color.g,
+ .b = color.b,
+ .a = color.a,
+ });
+ return LIQ_OK;
+}
+
+LIQ_NONNULL static liq_error liq_histogram_add_fixed_color_f(liq_histogram *hist, f_pixel color)
+{
+ if (hist->fixed_colors_count > 255) return LIQ_UNSUPPORTED;
+
+ hist->fixed_colors[hist->fixed_colors_count++] = color;
+ return LIQ_OK;
+}
+
+LIQ_EXPORT LIQ_NONNULL liq_error liq_histogram_add_fixed_color(liq_histogram *hist, liq_color color, double gamma)
+{
+ if (!CHECK_STRUCT_TYPE(hist, liq_histogram)) return LIQ_INVALID_POINTER;
+
+ float gamma_lut[256];
+ to_f_set_gamma(gamma_lut, gamma ? gamma : 0.45455);
+ const f_pixel px = rgba_to_f(gamma_lut, (rgba_pixel){
+ .r = color.r,
+ .g = color.g,
+ .b = color.b,
+ .a = color.a,
+ });
+ return liq_histogram_add_fixed_color_f(hist, px);
+}
+
+LIQ_NONNULL static bool liq_image_use_low_memory(liq_image *img)
+{
+ img->temp_f_row = img->malloc(sizeof(img->f_pixels[0]) * LIQ_TEMP_ROW_WIDTH(img->width) * omp_get_max_threads());
+ return img->temp_f_row != NULL;
+}
+
+LIQ_NONNULL static bool liq_image_should_use_low_memory(liq_image *img, const bool low_memory_hint)
+{
+ return (size_t)img->width * (size_t)img->height > (low_memory_hint ? LIQ_HIGH_MEMORY_LIMIT/8 : LIQ_HIGH_MEMORY_LIMIT) / sizeof(f_pixel); // Watch out for integer overflow
+}
+
+static liq_image *liq_image_create_internal(const liq_attr *attr, rgba_pixel* rows[], liq_image_get_rgba_row_callback *row_callback, void *row_callback_user_info, int width, int height, double gamma)
+{
+ if (gamma < 0 || gamma > 1.0) {
+ liq_log_error(attr, "gamma must be >= 0 and <= 1 (try 1/gamma instead)");
+ return NULL;
+ }
+
+ if (!rows && !row_callback) {
+ liq_log_error(attr, "missing row data");
+ return NULL;
+ }
+
+ liq_image *img = attr->malloc(sizeof(liq_image));
+ if (!img) return NULL;
+ *img = (liq_image){
+ .magic_header = liq_image_magic,
+ .malloc = attr->malloc,
+ .free = attr->free,
+ .width = width, .height = height,
+ .gamma = gamma ? gamma : 0.45455,
+ .rows = rows,
+ .row_callback = row_callback,
+ .row_callback_user_info = row_callback_user_info,
+ };
+
+ if (!rows) {
+ img->temp_row = attr->malloc(sizeof(img->temp_row[0]) * LIQ_TEMP_ROW_WIDTH(width) * omp_get_max_threads());
+ if (!img->temp_row) return NULL;
+ }
+
+ // if image is huge or converted pixels are not likely to be reused then don't cache converted pixels
+ if (liq_image_should_use_low_memory(img, !img->temp_row && !attr->use_contrast_maps && !attr->use_dither_map)) {
+ verbose_print(attr, " conserving memory");
+ if (!liq_image_use_low_memory(img)) return NULL;
+ }
+
+ return img;
+}
+
+LIQ_EXPORT LIQ_NONNULL liq_error liq_image_set_memory_ownership(liq_image *img, int ownership_flags)
+{
+ if (!CHECK_STRUCT_TYPE(img, liq_image)) return LIQ_INVALID_POINTER;
+ if (!img->rows || !ownership_flags || (ownership_flags & ~(LIQ_OWN_ROWS|LIQ_OWN_PIXELS))) {
+ return LIQ_VALUE_OUT_OF_RANGE;
+ }
+
+ if (ownership_flags & LIQ_OWN_ROWS) {
+ if (img->free_rows_internal) return LIQ_VALUE_OUT_OF_RANGE;
+ img->free_rows = true;
+ }
+
+ if (ownership_flags & LIQ_OWN_PIXELS) {
+ img->free_pixels = true;
+ if (!img->pixels) {
+ // for simplicity of this API there's no explicit bitmap argument,
+ // so the row with the lowest address is assumed to be at the start of the bitmap
+ img->pixels = img->rows[0];
+ for(unsigned int i=1; i < img->height; i++) {
+ img->pixels = MIN(img->pixels, img->rows[i]);
+ }
+ }
+ }
+
+ return LIQ_OK;
+}
+
+LIQ_NONNULL static void liq_image_free_maps(liq_image *input_image);
+LIQ_NONNULL static void liq_image_free_dither_map(liq_image *input_image);
+LIQ_NONNULL static void liq_image_free_importance_map(liq_image *input_image);
+
+LIQ_EXPORT LIQ_NONNULL liq_error liq_image_set_importance_map(liq_image *img, unsigned char importance_map[], size_t buffer_size, enum liq_ownership ownership) {
+ if (!CHECK_STRUCT_TYPE(img, liq_image)) return LIQ_INVALID_POINTER;
+ if (!CHECK_USER_POINTER(importance_map)) return LIQ_INVALID_POINTER;
+
+ const size_t required_size = (size_t)img->width * (size_t)img->height;
+ if (buffer_size < required_size) {
+ return LIQ_BUFFER_TOO_SMALL;
+ }
+
+ if (ownership == LIQ_COPY_PIXELS) {
+ unsigned char *tmp = img->malloc(required_size);
+ if (!tmp) {
+ return LIQ_OUT_OF_MEMORY;
+ }
+ memcpy(tmp, importance_map, required_size);
+ importance_map = tmp;
+ } else if (ownership != LIQ_OWN_PIXELS) {
+ return LIQ_UNSUPPORTED;
+ }
+
+ liq_image_free_importance_map(img);
+ img->importance_map = importance_map;
+
+ return LIQ_OK;
+}
+
+LIQ_EXPORT LIQ_NONNULL liq_error liq_image_set_background(liq_image *img, liq_image *background)
+{
+ if (!CHECK_STRUCT_TYPE(img, liq_image)) return LIQ_INVALID_POINTER;
+ if (!CHECK_STRUCT_TYPE(background, liq_image)) return LIQ_INVALID_POINTER;
+
+ if (background->background) {
+ return LIQ_UNSUPPORTED;
+ }
+ if (img->width != background->width || img->height != background->height) {
+ return LIQ_BUFFER_TOO_SMALL;
+ }
+
+ if (img->background) {
+ liq_image_destroy(img->background);
+ }
+
+ img->background = background;
+ liq_image_free_dither_map(img); // Force it to be re-analyzed with the background
+
+ return LIQ_OK;
+}
+
+LIQ_NONNULL static bool check_image_size(const liq_attr *attr, const int width, const int height)
+{
+ if (!CHECK_STRUCT_TYPE(attr, liq_attr)) {
+ return false;
+ }
+
+ if (width <= 0 || height <= 0) {
+ liq_log_error(attr, "width and height must be > 0");
+ return false;
+ }
+
+ if (width > INT_MAX/sizeof(rgba_pixel)/height || width > INT_MAX/16/sizeof(f_pixel) || height > INT_MAX/sizeof(size_t)) {
+ liq_log_error(attr, "image too large");
+ return false;
+ }
+ return true;
+}
+
+LIQ_EXPORT liq_image *liq_image_create_custom(const liq_attr *attr, liq_image_get_rgba_row_callback *row_callback, void* user_info, int width, int height, double gamma)
+{
+ if (!check_image_size(attr, width, height)) {
+ return NULL;
+ }
+ return liq_image_create_internal(attr, NULL, row_callback, user_info, width, height, gamma);
+}
+
+LIQ_EXPORT liq_image *liq_image_create_rgba_rows(const liq_attr *attr, void *const rows[], int width, int height, double gamma)
+{
+ if (!check_image_size(attr, width, height)) {
+ return NULL;
+ }
+
+ for(int i=0; i < height; i++) {
+ if (!CHECK_USER_POINTER(rows+i) || !CHECK_USER_POINTER(rows[i])) {
+ liq_log_error(attr, "invalid row pointers");
+ return NULL;
+ }
+ }
+ return liq_image_create_internal(attr, (rgba_pixel**)rows, NULL, NULL, width, height, gamma);
+}
+
+LIQ_EXPORT LIQ_NONNULL liq_image *liq_image_create_rgba(const liq_attr *attr, const void* bitmap, int width, int height, double gamma)
+{
+ if (!check_image_size(attr, width, height)) {
+ return NULL;
+ }
+ if (!CHECK_USER_POINTER(bitmap)) {
+ liq_log_error(attr, "invalid bitmap pointer");
+ return NULL;
+ }
+
+ rgba_pixel *const pixels = (rgba_pixel *const)bitmap;
+ rgba_pixel **rows = attr->malloc(sizeof(rows[0])*height);
+ if (!rows) return NULL;
+
+ for(int i=0; i < height; i++) {
+ rows[i] = pixels + width * i;
+ }
+
+ liq_image *image = liq_image_create_internal(attr, rows, NULL, NULL, width, height, gamma);
+ if (!image) {
+ attr->free(rows);
+ return NULL;
+ }
+ image->free_rows = true;
+ image->free_rows_internal = true;
+ return image;
+}
+
+NEVER_INLINE LIQ_EXPORT void liq_executing_user_callback(liq_image_get_rgba_row_callback *callback, liq_color *temp_row, int row, int width, void *user_info);
+LIQ_EXPORT void liq_executing_user_callback(liq_image_get_rgba_row_callback *callback, liq_color *temp_row, int row, int width, void *user_info)
+{
+ assert(callback);
+ assert(temp_row);
+ callback(temp_row, row, width, user_info);
+}
+
+LIQ_NONNULL inline static bool liq_image_has_rgba_pixels(const liq_image *img)
+{
+ if (!CHECK_STRUCT_TYPE(img, liq_image)) {
+ return false;
+ }
+ return img->rows || (img->temp_row && img->row_callback);
+}
+
+LIQ_NONNULL inline static bool liq_image_can_use_rgba_rows(const liq_image *img)
+{
+ assert(liq_image_has_rgba_pixels(img));
+ return img->rows;
+}
+
+LIQ_NONNULL static const rgba_pixel *liq_image_get_row_rgba(liq_image *img, unsigned int row)
+{
+ if (liq_image_can_use_rgba_rows(img)) {
+ return img->rows[row];
+ }
+
+ assert(img->temp_row);
+ rgba_pixel *temp_row = img->temp_row + LIQ_TEMP_ROW_WIDTH(img->width) * omp_get_thread_num();
+ if (img->rows) {
+ memcpy(temp_row, img->rows[row], img->width * sizeof(temp_row[0]));
+ } else {
+ liq_executing_user_callback(img->row_callback, (liq_color*)temp_row, row, img->width, img->row_callback_user_info);
+ }
+
+ return temp_row;
+}
+
+LIQ_NONNULL static void convert_row_to_f(liq_image *img, f_pixel *row_f_pixels, const unsigned int row, const float gamma_lut[])
+{
+ assert(row_f_pixels);
+ assert(!USE_SSE || 0 == ((uintptr_t)row_f_pixels & 15));
+
+ const rgba_pixel *const row_pixels = liq_image_get_row_rgba(img, row);
+
+ for(unsigned int col=0; col < img->width; col++) {
+ row_f_pixels[col] = rgba_to_f(gamma_lut, row_pixels[col]);
+ }
+}
+
+LIQ_NONNULL static bool liq_image_get_row_f_init(liq_image *img)
+{
+ assert(omp_get_thread_num() == 0);
+ if (img->f_pixels) {
+ return true;
+ }
+ if (!liq_image_should_use_low_memory(img, false)) {
+ img->f_pixels = img->malloc(sizeof(img->f_pixels[0]) * img->width * img->height);
+ }
+ if (!img->f_pixels) {
+ return liq_image_use_low_memory(img);
+ }
+
+ if (!liq_image_has_rgba_pixels(img)) {
+ return false;
+ }
+
+ float gamma_lut[256];
+ to_f_set_gamma(gamma_lut, img->gamma);
+ for(unsigned int i=0; i < img->height; i++) {
+ convert_row_to_f(img, &img->f_pixels[i*img->width], i, gamma_lut);
+ }
+ return true;
+}
+
+LIQ_NONNULL static const f_pixel *liq_image_get_row_f(liq_image *img, unsigned int row)
+{
+ if (!img->f_pixels) {
+ assert(img->temp_f_row); // init should have done that
+ float gamma_lut[256];
+ to_f_set_gamma(gamma_lut, img->gamma);
+ f_pixel *row_for_thread = img->temp_f_row + LIQ_TEMP_ROW_WIDTH(img->width) * omp_get_thread_num();
+ convert_row_to_f(img, row_for_thread, row, gamma_lut);
+ return row_for_thread;
+ }
+ return img->f_pixels + img->width * row;
+}
+
+LIQ_EXPORT LIQ_NONNULL int liq_image_get_width(const liq_image *input_image)
+{
+ if (!CHECK_STRUCT_TYPE(input_image, liq_image)) return -1;
+ return input_image->width;
+}
+
+LIQ_EXPORT LIQ_NONNULL int liq_image_get_height(const liq_image *input_image)
+{
+ if (!CHECK_STRUCT_TYPE(input_image, liq_image)) return -1;
+ return input_image->height;
+}
+
+typedef void free_func(void*);
+
+LIQ_NONNULL static free_func *get_default_image_free_func(liq_image *img)
+{
+ // When default allocator is used then user-supplied pointers must be freed with free()
+ if (img->free != liq_aligned_free) {
+ return img->free;
+ }
+ return free;
+}
+
+LIQ_NONNULL static free_func *get_default_rows_free_func(liq_image *img)
+{
+ // When default allocator is used then user-supplied pointers must be freed with free()
+ if (img->free_rows_internal || img->free != liq_aligned_free) {
+ return img->free;
+ }
+ return free;
+}
+
+LIQ_NONNULL static void liq_image_free_rgba_source(liq_image *input_image)
+{
+ if (input_image->free_pixels && input_image->pixels) {
+ get_default_image_free_func(input_image)(input_image->pixels);
+ input_image->pixels = NULL;
+ }
+
+ if (input_image->free_rows && input_image->rows) {
+ get_default_rows_free_func(input_image)(input_image->rows);
+ input_image->rows = NULL;
+ }
+}
+
+LIQ_NONNULL static void liq_image_free_importance_map(liq_image *input_image) {
+ if (input_image->importance_map) {
+ input_image->free(input_image->importance_map);
+ input_image->importance_map = NULL;
+ }
+}
+
+LIQ_NONNULL static void liq_image_free_maps(liq_image *input_image) {
+ liq_image_free_importance_map(input_image);
+
+ if (input_image->edges) {
+ input_image->free(input_image->edges);
+ input_image->edges = NULL;
+ }
+ liq_image_free_dither_map(input_image);
+}
+
+LIQ_NONNULL static void liq_image_free_dither_map(liq_image *input_image) {
+ if (input_image->dither_map) {
+ input_image->free(input_image->dither_map);
+ input_image->dither_map = NULL;
+ }
+}
+
+LIQ_EXPORT LIQ_NONNULL void liq_image_destroy(liq_image *input_image)
+{
+ if (!CHECK_STRUCT_TYPE(input_image, liq_image)) return;
+
+ liq_image_free_rgba_source(input_image);
+
+ liq_image_free_maps(input_image);
+
+ if (input_image->f_pixels) {
+ input_image->free(input_image->f_pixels);
+ }
+
+ if (input_image->temp_row) {
+ input_image->free(input_image->temp_row);
+ }
+
+ if (input_image->temp_f_row) {
+ input_image->free(input_image->temp_f_row);
+ }
+
+ if (input_image->background) {
+ liq_image_destroy(input_image->background);
+ }
+
+ input_image->magic_header = liq_freed_magic;
+ input_image->free(input_image);
+}
+
+LIQ_EXPORT liq_histogram* liq_histogram_create(const liq_attr* attr)
+{
+ if (!CHECK_STRUCT_TYPE(attr, liq_attr)) {
+ return NULL;
+ }
+
+ liq_histogram *hist = attr->malloc(sizeof(liq_histogram));
+ if (!hist) return NULL;
+ *hist = (liq_histogram) {
+ .magic_header = liq_histogram_magic,
+ .malloc = attr->malloc,
+ .free = attr->free,
+
+ .ignorebits = MAX(attr->min_posterization_output, attr->min_posterization_input),
+ };
+ return hist;
+}
+
+LIQ_EXPORT LIQ_NONNULL void liq_histogram_destroy(liq_histogram *hist)
+{
+ if (!CHECK_STRUCT_TYPE(hist, liq_histogram)) return;
+ hist->magic_header = liq_freed_magic;
+
+ pam_freeacolorhash(hist->acht);
+ hist->free(hist);
+}
+
+LIQ_EXPORT LIQ_NONNULL liq_result *liq_quantize_image(liq_attr *attr, liq_image *img)
+{
+ liq_result *res;
+ if (LIQ_OK != liq_image_quantize(img, attr, &res)) {
+ return NULL;
+ }
+ return res;
+}
+
+LIQ_EXPORT LIQ_NONNULL liq_error liq_image_quantize(liq_image *const img, liq_attr *const attr, liq_result **result_output)
+{
+ if (!CHECK_STRUCT_TYPE(attr, liq_attr)) return LIQ_INVALID_POINTER;
+ if (!liq_image_has_rgba_pixels(img)) {
+ return LIQ_UNSUPPORTED;
+ }
+
+ liq_histogram *hist = liq_histogram_create(attr);
+ if (!hist) {
+ return LIQ_OUT_OF_MEMORY;
+ }
+ liq_error err = liq_histogram_add_image(hist, attr, img);
+ if (LIQ_OK != err) {
+ liq_histogram_destroy(hist);
+ return err;
+ }
+
+ err = liq_histogram_quantize_internal(hist, attr, false, result_output);
+ liq_histogram_destroy(hist);
+
+ return err;
+}
+
+LIQ_EXPORT LIQ_NONNULL liq_error liq_histogram_quantize(liq_histogram *input_hist, liq_attr *attr, liq_result **result_output) {
+ return liq_histogram_quantize_internal(input_hist, attr, true, result_output);
+}
+
+LIQ_NONNULL static liq_error liq_histogram_quantize_internal(liq_histogram *input_hist, liq_attr *attr, bool fixed_result_colors, liq_result **result_output)
+{
+ if (!CHECK_USER_POINTER(result_output)) return LIQ_INVALID_POINTER;
+ *result_output = NULL;
+
+ if (!CHECK_STRUCT_TYPE(attr, liq_attr)) return LIQ_INVALID_POINTER;
+ if (!CHECK_STRUCT_TYPE(input_hist, liq_histogram)) return LIQ_INVALID_POINTER;
+
+ if (liq_progress(attr, 0)) return LIQ_ABORTED;
+
+ histogram *hist;
+ liq_error err = finalize_histogram(input_hist, attr, &hist);
+ if (err != LIQ_OK) {
+ return err;
+ }
+
+ err = pngquant_quantize(hist, attr, input_hist->fixed_colors_count, input_hist->fixed_colors, input_hist->gamma, fixed_result_colors, result_output);
+ pam_freeacolorhist(hist);
+
+ return err;
+}
+
+LIQ_EXPORT LIQ_NONNULL liq_error liq_set_dithering_level(liq_result *res, float dither_level)
+{
+ if (!CHECK_STRUCT_TYPE(res, liq_result)) return LIQ_INVALID_POINTER;
+
+ if (res->remapping) {
+ liq_remapping_result_destroy(res->remapping);
+ res->remapping = NULL;
+ }
+
+ if (dither_level < 0 || dither_level > 1.0f) return LIQ_VALUE_OUT_OF_RANGE;
+ res->dither_level = dither_level;
+ return LIQ_OK;
+}
+
+LIQ_NONNULL static liq_remapping_result *liq_remapping_result_create(liq_result *result)
+{
+ if (!CHECK_STRUCT_TYPE(result, liq_result)) {
+ return NULL;
+ }
+
+ liq_remapping_result *res = result->malloc(sizeof(liq_remapping_result));
+ if (!res) return NULL;
+ *res = (liq_remapping_result) {
+ .magic_header = liq_remapping_result_magic,
+ .malloc = result->malloc,
+ .free = result->free,
+ .dither_level = result->dither_level,
+ .use_dither_map = result->use_dither_map,
+ .palette_error = result->palette_error,
+ .gamma = result->gamma,
+ .palette = pam_duplicate_colormap(result->palette),
+ .progress_callback = result->progress_callback,
+ .progress_callback_user_info = result->progress_callback_user_info,
+ .progress_stage1 = result->use_dither_map ? 20 : 0,
+ };
+ return res;
+}
+
+LIQ_EXPORT LIQ_NONNULL double liq_get_output_gamma(const liq_result *result)
+{
+ if (!CHECK_STRUCT_TYPE(result, liq_result)) return -1;
+
+ return result->gamma;
+}
+
+LIQ_NONNULL static void liq_remapping_result_destroy(liq_remapping_result *result)
+{
+ if (!CHECK_STRUCT_TYPE(result, liq_remapping_result)) return;
+
+ if (result->palette) pam_freecolormap(result->palette);
+ if (result->pixels) result->free(result->pixels);
+
+ result->magic_header = liq_freed_magic;
+ result->free(result);
+}
+
+LIQ_EXPORT LIQ_NONNULL void liq_result_destroy(liq_result *res)
+{
+ if (!CHECK_STRUCT_TYPE(res, liq_result)) return;
+
+ memset(&res->int_palette, 0, sizeof(liq_palette));
+
+ if (res->remapping) {
+ memset(&res->remapping->int_palette, 0, sizeof(liq_palette));
+ liq_remapping_result_destroy(res->remapping);
+ }
+
+ pam_freecolormap(res->palette);
+
+ res->magic_header = liq_freed_magic;
+ res->free(res);
+}
+
+
+LIQ_EXPORT LIQ_NONNULL double liq_get_quantization_error(const liq_result *result) {
+ if (!CHECK_STRUCT_TYPE(result, liq_result)) return -1;
+
+ if (result->palette_error >= 0) {
+ return mse_to_standard_mse(result->palette_error);
+ }
+
+ return -1;
+}
+
+LIQ_EXPORT LIQ_NONNULL double liq_get_remapping_error(const liq_result *result) {
+ if (!CHECK_STRUCT_TYPE(result, liq_result)) return -1;
+
+ if (result->remapping && result->remapping->palette_error >= 0) {
+ return mse_to_standard_mse(result->remapping->palette_error);
+ }
+
+ return -1;
+}
+
+LIQ_EXPORT LIQ_NONNULL int liq_get_quantization_quality(const liq_result *result) {
+ if (!CHECK_STRUCT_TYPE(result, liq_result)) return -1;
+
+ if (result->palette_error >= 0) {
+ return mse_to_quality(result->palette_error);
+ }
+
+ return -1;
+}
+
+LIQ_EXPORT LIQ_NONNULL int liq_get_remapping_quality(const liq_result *result) {
+ if (!CHECK_STRUCT_TYPE(result, liq_result)) return -1;
+
+ if (result->remapping && result->remapping->palette_error >= 0) {
+ return mse_to_quality(result->remapping->palette_error);
+ }
+
+ return -1;
+}
+
+LIQ_NONNULL static int compare_popularity(const void *ch1, const void *ch2)
+{
+ const float v1 = ((const colormap_item*)ch1)->popularity;
+ const float v2 = ((const colormap_item*)ch2)->popularity;
+ return v1 > v2 ? -1 : 1;
+}
+
+LIQ_NONNULL static void sort_palette_qsort(colormap *map, int start, int nelem)
+{
+ if (!nelem) return;
+ qsort(map->palette + start, nelem, sizeof(map->palette[0]), compare_popularity);
+}
+
+#define SWAP_PALETTE(map, a,b) { \
+ const colormap_item tmp = (map)->palette[(a)]; \
+ (map)->palette[(a)] = (map)->palette[(b)]; \
+ (map)->palette[(b)] = tmp; }
+
+LIQ_NONNULL static void sort_palette(colormap *map, const liq_attr *options)
+{
+ /*
+ ** Step 3.5 [GRR]: remap the palette colors so that all entries with
+ ** the maximal alpha value (i.e., fully opaque) are at the end and can
+ ** therefore be omitted from the tRNS chunk.
+ */
+ if (options->last_index_transparent) {
+ for(unsigned int i=0; i < map->colors; i++) {
+ if (map->palette[i].acolor.a < 1.f/256.f) {
+ const unsigned int old = i, transparent_dest = map->colors-1;
+
+ SWAP_PALETTE(map, transparent_dest, old);
+
+ /* colors sorted by popularity make pngs slightly more compressible */
+ sort_palette_qsort(map, 0, map->colors-1);
+ return;
+ }
+ }
+ }
+
+ unsigned int non_fixed_colors = 0;
+ for(unsigned int i = 0; i < map->colors; i++) {
+ if (map->palette[i].fixed) {
+ break;
+ }
+ non_fixed_colors++;
+ }
+
+ /* move transparent colors to the beginning to shrink trns chunk */
+ unsigned int num_transparent = 0;
+ for(unsigned int i = 0; i < non_fixed_colors; i++) {
+ if (map->palette[i].acolor.a < 255.f/256.f) {
+ // current transparent color is swapped with earlier opaque one
+ if (i != num_transparent) {
+ SWAP_PALETTE(map, num_transparent, i);
+ i--;
+ }
+ num_transparent++;
+ }
+ }
+
+ liq_verbose_printf(options, " eliminated opaque tRNS-chunk entries...%d entr%s transparent", num_transparent, (num_transparent == 1)? "y" : "ies");
+
+ /* colors sorted by popularity make pngs slightly more compressible
+ * opaque and transparent are sorted separately
+ */
+ sort_palette_qsort(map, 0, num_transparent);
+ sort_palette_qsort(map, num_transparent, non_fixed_colors - num_transparent);
+
+ if (non_fixed_colors > 9 && map->colors > 16) {
+ SWAP_PALETTE(map, 7, 1); // slightly improves compression
+ SWAP_PALETTE(map, 8, 2);
+ SWAP_PALETTE(map, 9, 3);
+ }
+}
+
+inline static unsigned int posterize_channel(unsigned int color, unsigned int bits)
+{
+ return (color & ~((1<> (8-bits));
+}
+
+LIQ_NONNULL static void set_rounded_palette(liq_palette *const dest, colormap *const map, const double gamma, unsigned int posterize)
+{
+ float gamma_lut[256];
+ to_f_set_gamma(gamma_lut, gamma);
+
+ dest->count = map->colors;
+ for(unsigned int x = 0; x < map->colors; ++x) {
+ rgba_pixel px = f_to_rgb(gamma, map->palette[x].acolor);
+
+ px.r = posterize_channel(px.r, posterize);
+ px.g = posterize_channel(px.g, posterize);
+ px.b = posterize_channel(px.b, posterize);
+ px.a = posterize_channel(px.a, posterize);
+
+ map->palette[x].acolor = rgba_to_f(gamma_lut, px); /* saves rounding error introduced by to_rgb, which makes remapping & dithering more accurate */
+
+ if (!px.a && !map->palette[x].fixed) {
+ px.r = 71; px.g = 112; px.b = 76;
+ }
+
+ dest->entries[x] = (liq_color){.r=px.r,.g=px.g,.b=px.b,.a=px.a};
+ }
+}
+
+LIQ_EXPORT LIQ_NONNULL const liq_palette *liq_get_palette(liq_result *result)
+{
+ if (!CHECK_STRUCT_TYPE(result, liq_result)) return NULL;
+
+ if (result->remapping && result->remapping->int_palette.count) {
+ return &result->remapping->int_palette;
+ }
+
+ if (!result->int_palette.count) {
+ set_rounded_palette(&result->int_palette, result->palette, result->gamma, result->min_posterization_output);
+ }
+ return &result->int_palette;
+}
+
+LIQ_NONNULL static float remap_to_palette(liq_image *const input_image, unsigned char *const *const output_pixels, colormap *const map)
+{
+ const int rows = input_image->height;
+ const unsigned int cols = input_image->width;
+ double remapping_error=0;
+
+ if (!liq_image_get_row_f_init(input_image)) {
+ return -1;
+ }
+ if (input_image->background && !liq_image_get_row_f_init(input_image->background)) {
+ return -1;
+ }
+
+ const colormap_item *acolormap = map->palette;
+
+ struct nearest_map *const n = nearest_init(map);
+ liq_image *background = input_image->background;
+ const int transparent_index = background ? nearest_search(n, &(f_pixel){0,0,0,0}, 0, NULL) : -1;
+ if (background && acolormap[transparent_index].acolor.a > 1.f/256.f) {
+ // palette unsuitable for using the bg
+ background = NULL;
+ }
+
+
+ const unsigned int max_threads = omp_get_max_threads();
+ LIQ_ARRAY(kmeans_state, average_color, (KMEANS_CACHE_LINE_GAP+map->colors) * max_threads);
+ kmeans_init(map, max_threads, average_color);
+
+#if __GNUC__ >= 9 || __clang__
+ #pragma omp parallel for if (rows*cols > 3000) \
+ schedule(static) default(none) shared(background,acolormap,average_color,cols,input_image,map,n,output_pixels,rows,transparent_index) reduction(+:remapping_error)
+#endif
+ for(int row = 0; row < rows; ++row) {
+ const f_pixel *const row_pixels = liq_image_get_row_f(input_image, row);
+ const f_pixel *const bg_pixels = background && acolormap[transparent_index].acolor.a < 1.f/256.f ? liq_image_get_row_f(background, row) : NULL;
+
+ unsigned int last_match=0;
+ for(unsigned int col = 0; col < cols; ++col) {
+ float diff;
+ last_match = nearest_search(n, &row_pixels[col], last_match, &diff);
+ if (bg_pixels) {
+ float bg_diff = colordifference(bg_pixels[col], acolormap[last_match].acolor);
+ if (bg_diff <= diff) {
+ diff = bg_diff;
+ last_match = transparent_index;
+ }
+ }
+ output_pixels[row][col] = last_match;
+
+ remapping_error += diff;
+ if (last_match != transparent_index) {
+ kmeans_update_color(row_pixels[col], 1.0, map, last_match, omp_get_thread_num(), average_color);
+ }
+ }
+ }
+
+ kmeans_finalize(map, max_threads, average_color);
+
+ nearest_free(n);
+
+ return remapping_error / (input_image->width * input_image->height);
+}
+
+inline static f_pixel get_dithered_pixel(const float dither_level, const float max_dither_error, const f_pixel thiserr, const f_pixel px)
+{
+ /* Use Floyd-Steinberg errors to adjust actual color. */
+ const float sr = thiserr.r * dither_level,
+ sg = thiserr.g * dither_level,
+ sb = thiserr.b * dither_level,
+ sa = thiserr.a * dither_level;
+
+ float ratio = 1.0;
+ const float max_overflow = 1.1f;
+ const float max_underflow = -0.1f;
+
+ // allowing some overflow prevents undithered bands caused by clamping of all channels
+ if (px.r + sr > max_overflow) ratio = MIN(ratio, (max_overflow -px.r)/sr);
+ else { if (px.r + sr < max_underflow) ratio = MIN(ratio, (max_underflow-px.r)/sr); }
+ if (px.g + sg > max_overflow) ratio = MIN(ratio, (max_overflow -px.g)/sg);
+ else { if (px.g + sg < max_underflow) ratio = MIN(ratio, (max_underflow-px.g)/sg); }
+ if (px.b + sb > max_overflow) ratio = MIN(ratio, (max_overflow -px.b)/sb);
+ else { if (px.b + sb < max_underflow) ratio = MIN(ratio, (max_underflow-px.b)/sb); }
+
+ float a = px.a + sa;
+ if (a > 1.f) { a = 1.f; }
+ else if (a < 0) { a = 0; }
+
+ // If dithering error is crazy high, don't propagate it that much
+ // This prevents crazy geen pixels popping out of the blue (or red or black! ;)
+ const float dither_error = sr*sr + sg*sg + sb*sb + sa*sa;
+ if (dither_error > max_dither_error) {
+ ratio *= 0.8f;
+ } else if (dither_error < 2.f/256.f/256.f) {
+ // don't dither areas that don't have noticeable error — makes file smaller
+ return px;
+ }
+
+ return (f_pixel) {
+ .r=px.r + sr * ratio,
+ .g=px.g + sg * ratio,
+ .b=px.b + sb * ratio,
+ .a=a,
+ };
+}
+
+/**
+ Uses edge/noise map to apply dithering only to flat areas. Dithering on edges creates jagged lines, and noisy areas are "naturally" dithered.
+
+ If output_image_is_remapped is true, only pixels noticeably changed by error diffusion will be written to output image.
+ */
+LIQ_NONNULL static bool remap_to_palette_floyd(liq_image *input_image, unsigned char *const output_pixels[], liq_remapping_result *quant, const float max_dither_error, const bool output_image_is_remapped)
+{
+ const int rows = input_image->height, cols = input_image->width;
+ const unsigned char *dither_map = quant->use_dither_map ? (input_image->dither_map ? input_image->dither_map : input_image->edges) : NULL;
+
+ const colormap *map = quant->palette;
+ const colormap_item *acolormap = map->palette;
+
+ if (!liq_image_get_row_f_init(input_image)) {
+ return false;
+ }
+ if (input_image->background && !liq_image_get_row_f_init(input_image->background)) {
+ return false;
+ }
+
+ /* Initialize Floyd-Steinberg error vectors. */
+ const size_t errwidth = cols+2;
+ f_pixel *restrict thiserr = input_image->malloc(errwidth * sizeof(thiserr[0]) * 2); // +2 saves from checking out of bounds access
+ if (!thiserr) return false;
+ f_pixel *restrict nexterr = thiserr + errwidth;
+ memset(thiserr, 0, errwidth * sizeof(thiserr[0]));
+
+ bool ok = true;
+ struct nearest_map *const n = nearest_init(map);
+ liq_image *background = input_image->background;
+ const int transparent_index = background ? nearest_search(n, &(f_pixel){0,0,0,0}, 0, NULL) : -1;
+ if (background && acolormap[transparent_index].acolor.a > 1.f/256.f) {
+ // palette unsuitable for using the bg
+ background = NULL;
+ }
+
+ // response to this value is non-linear and without it any value < 0.8 would give almost no dithering
+ float base_dithering_level = quant->dither_level;
+ base_dithering_level = 1.f - (1.f-base_dithering_level)*(1.f-base_dithering_level);
+
+ if (dither_map) {
+ base_dithering_level *= 1.f/255.f; // convert byte to float
+ }
+ base_dithering_level *= 15.f/16.f; // prevent small errors from accumulating
+
+ int fs_direction = 1;
+ unsigned int last_match=0;
+ for (int row = 0; row < rows; ++row) {
+ if (liq_remap_progress(quant, quant->progress_stage1 + row * (100.f - quant->progress_stage1) / rows)) {
+ ok = false;
+ break;
+ }
+
+ memset(nexterr, 0, errwidth * sizeof(nexterr[0]));
+
+ int col = (fs_direction > 0) ? 0 : (cols - 1);
+ const f_pixel *const row_pixels = liq_image_get_row_f(input_image, row);
+ const f_pixel *const bg_pixels = background && acolormap[transparent_index].acolor.a < 1.f/256.f ? liq_image_get_row_f(background, row) : NULL;
+ int undithered_bg_used = 0;
+
+ do {
+ float dither_level = base_dithering_level;
+ if (dither_map) {
+ dither_level *= dither_map[row*cols + col];
+ }
+
+ const f_pixel spx = get_dithered_pixel(dither_level, max_dither_error, thiserr[col + 1], row_pixels[col]);
+
+ const unsigned int guessed_match = output_image_is_remapped ? output_pixels[row][col] : last_match;
+ float dither_diff;
+ last_match = nearest_search(n, &spx, guessed_match, &dither_diff);
+ f_pixel output_px = acolormap[last_match].acolor;
+ // this is for animgifs
+ if (bg_pixels) {
+ // if the background makes better match *with* dithering, it's a definitive win
+ float bg_for_dither_diff = colordifference(spx, bg_pixels[col]);
+ if (bg_for_dither_diff <= dither_diff) {
+ output_px = bg_pixels[col];
+ last_match = transparent_index;
+ } else if (undithered_bg_used > 1) {
+ // the undithered fallback can cause artifacts when too many undithered pixels accumulate a big dithering error
+ // so periodically ignore undithered fallback to prevent that
+ undithered_bg_used = 0;
+ } else {
+ // if dithering is not applied, there's a high risk of creating artifacts (flat areas, error accumulating badly),
+ // OTOH poor dithering disturbs static backgrounds and creates oscilalting frames that break backgrounds
+ // back and forth in two differently bad ways
+ float max_diff = colordifference(row_pixels[col], bg_pixels[col]);
+ float dithered_diff = colordifference(row_pixels[col], output_px);
+ // if dithering is worse than natural difference between frames
+ // (this rule dithers moving areas, but does not dither static areas)
+ if (dithered_diff > max_diff) {
+ // then see if an undithered color is closer to the ideal
+ float undithered_diff = colordifference(row_pixels[col], acolormap[guessed_match].acolor);
+ if (undithered_diff < max_diff) {
+ undithered_bg_used++;
+ output_px = acolormap[guessed_match].acolor;
+ last_match = guessed_match;
+ }
+ }
+ }
+ }
+
+ output_pixels[row][col] = last_match;
+
+ f_pixel err = {
+ .r = (spx.r - output_px.r),
+ .g = (spx.g - output_px.g),
+ .b = (spx.b - output_px.b),
+ .a = (spx.a - output_px.a),
+ };
+
+ // If dithering error is crazy high, don't propagate it that much
+ // This prevents crazy geen pixels popping out of the blue (or red or black! ;)
+ if (err.r*err.r + err.g*err.g + err.b*err.b + err.a*err.a > max_dither_error) {
+ err.r *= 0.75f;
+ err.g *= 0.75f;
+ err.b *= 0.75f;
+ err.a *= 0.75f;
+ }
+
+ /* Propagate Floyd-Steinberg error terms. */
+ if (fs_direction > 0) {
+ thiserr[col + 2].a += err.a * (7.f/16.f);
+ thiserr[col + 2].r += err.r * (7.f/16.f);
+ thiserr[col + 2].g += err.g * (7.f/16.f);
+ thiserr[col + 2].b += err.b * (7.f/16.f);
+
+ nexterr[col + 2].a = err.a * (1.f/16.f);
+ nexterr[col + 2].r = err.r * (1.f/16.f);
+ nexterr[col + 2].g = err.g * (1.f/16.f);
+ nexterr[col + 2].b = err.b * (1.f/16.f);
+
+ nexterr[col + 1].a += err.a * (5.f/16.f);
+ nexterr[col + 1].r += err.r * (5.f/16.f);
+ nexterr[col + 1].g += err.g * (5.f/16.f);
+ nexterr[col + 1].b += err.b * (5.f/16.f);
+
+ nexterr[col ].a += err.a * (3.f/16.f);
+ nexterr[col ].r += err.r * (3.f/16.f);
+ nexterr[col ].g += err.g * (3.f/16.f);
+ nexterr[col ].b += err.b * (3.f/16.f);
+
+ } else {
+ thiserr[col ].a += err.a * (7.f/16.f);
+ thiserr[col ].r += err.r * (7.f/16.f);
+ thiserr[col ].g += err.g * (7.f/16.f);
+ thiserr[col ].b += err.b * (7.f/16.f);
+
+ nexterr[col ].a = err.a * (1.f/16.f);
+ nexterr[col ].r = err.r * (1.f/16.f);
+ nexterr[col ].g = err.g * (1.f/16.f);
+ nexterr[col ].b = err.b * (1.f/16.f);
+
+ nexterr[col + 1].a += err.a * (5.f/16.f);
+ nexterr[col + 1].r += err.r * (5.f/16.f);
+ nexterr[col + 1].g += err.g * (5.f/16.f);
+ nexterr[col + 1].b += err.b * (5.f/16.f);
+
+ nexterr[col + 2].a += err.a * (3.f/16.f);
+ nexterr[col + 2].r += err.r * (3.f/16.f);
+ nexterr[col + 2].g += err.g * (3.f/16.f);
+ nexterr[col + 2].b += err.b * (3.f/16.f);
+ }
+
+ // remapping is done in zig-zag
+ col += fs_direction;
+ if (fs_direction > 0) {
+ if (col >= cols) break;
+ } else {
+ if (col < 0) break;
+ }
+ } while(1);
+
+ f_pixel *const temperr = thiserr;
+ thiserr = nexterr;
+ nexterr = temperr;
+ fs_direction = -fs_direction;
+ }
+
+ input_image->free(MIN(thiserr, nexterr)); // MIN because pointers were swapped
+ nearest_free(n);
+
+ return ok;
+}
+
+/* fixed colors are always included in the palette, so it would be wasteful to duplicate them in palette from histogram */
+LIQ_NONNULL static void remove_fixed_colors_from_histogram(histogram *hist, const int fixed_colors_count, const f_pixel fixed_colors[], const float target_mse)
+{
+ const float max_difference = MAX(target_mse/2.f, 2.f/256.f/256.f);
+ if (fixed_colors_count) {
+ for(int j=0; j < hist->size; j++) {
+ for(unsigned int i=0; i < fixed_colors_count; i++) {
+ if (colordifference(hist->achv[j].acolor, fixed_colors[i]) < max_difference) {
+ hist->achv[j] = hist->achv[--hist->size]; // remove color from histogram by overwriting with the last entry
+ j--; break; // continue searching histogram
+ }
+ }
+ }
+ }
+}
+
+LIQ_EXPORT LIQ_NONNULL liq_error liq_histogram_add_colors(liq_histogram *input_hist, const liq_attr *options, const liq_histogram_entry entries[], int num_entries, double gamma)
+{
+ if (!CHECK_STRUCT_TYPE(options, liq_attr)) return LIQ_INVALID_POINTER;
+ if (!CHECK_STRUCT_TYPE(input_hist, liq_histogram)) return LIQ_INVALID_POINTER;
+ if (!CHECK_USER_POINTER(entries)) return LIQ_INVALID_POINTER;
+ if (gamma < 0 || gamma >= 1.0) return LIQ_VALUE_OUT_OF_RANGE;
+ if (num_entries <= 0 || num_entries > 1<<30) return LIQ_VALUE_OUT_OF_RANGE;
+
+ if (input_hist->ignorebits > 0 && input_hist->had_image_added) {
+ return LIQ_UNSUPPORTED;
+ }
+ input_hist->ignorebits = 0;
+
+ input_hist->had_image_added = true;
+ input_hist->gamma = gamma ? gamma : 0.45455;
+
+ if (!input_hist->acht) {
+ input_hist->acht = pam_allocacolorhash(~0, num_entries*num_entries, 0, options->malloc, options->free);
+ if (!input_hist->acht) {
+ return LIQ_OUT_OF_MEMORY;
+ }
+ }
+ // Fake image size. It's only for hash size estimates.
+ if (!input_hist->acht->cols) {
+ input_hist->acht->cols = num_entries;
+ }
+ input_hist->acht->rows += num_entries;
+
+ const unsigned int hash_size = input_hist->acht->hash_size;
+ for(int i=0; i < num_entries; i++) {
+ const rgba_pixel rgba = {
+ .r = entries[i].color.r,
+ .g = entries[i].color.g,
+ .b = entries[i].color.b,
+ .a = entries[i].color.a,
+ };
+ union rgba_as_int px = {rgba};
+ unsigned int hash;
+ if (px.rgba.a) {
+ hash = px.l % hash_size;
+ } else {
+ hash=0; px.l=0;
+ }
+ if (!pam_add_to_hash(input_hist->acht, hash, entries[i].count, px, i, num_entries)) {
+ return LIQ_OUT_OF_MEMORY;
+ }
+ }
+
+ return LIQ_OK;
+}
+
+LIQ_EXPORT LIQ_NONNULL liq_error liq_histogram_add_image(liq_histogram *input_hist, const liq_attr *options, liq_image *input_image)
+{
+ if (!CHECK_STRUCT_TYPE(options, liq_attr)) return LIQ_INVALID_POINTER;
+ if (!CHECK_STRUCT_TYPE(input_hist, liq_histogram)) return LIQ_INVALID_POINTER;
+ if (!CHECK_STRUCT_TYPE(input_image, liq_image)) return LIQ_INVALID_POINTER;
+
+ const unsigned int cols = input_image->width, rows = input_image->height;
+
+ if (!input_image->importance_map && options->use_contrast_maps) {
+ contrast_maps(input_image);
+ }
+
+ input_hist->gamma = input_image->gamma;
+
+ for(int i = 0; i < input_image->fixed_colors_count; i++) {
+ liq_error res = liq_histogram_add_fixed_color_f(input_hist, input_image->fixed_colors[i]);
+ if (res != LIQ_OK) {
+ return res;
+ }
+ }
+
+ /*
+ ** Step 2: attempt to make a histogram of the colors, unclustered.
+ ** If at first we don't succeed, increase ignorebits to increase color
+ ** coherence and try again.
+ */
+
+ if (liq_progress(options, options->progress_stage1 * 0.4f)) {
+ return LIQ_ABORTED;
+ }
+
+ const bool all_rows_at_once = liq_image_can_use_rgba_rows(input_image);
+
+ // Usual solution is to start from scratch when limit is exceeded, but that's not possible if it's not
+ // the first image added
+ const unsigned int max_histogram_entries = input_hist->had_image_added ? ~0 : options->max_histogram_entries;
+ do {
+ if (!input_hist->acht) {
+ input_hist->acht = pam_allocacolorhash(max_histogram_entries, rows*cols, input_hist->ignorebits, options->malloc, options->free);
+ }
+ if (!input_hist->acht) return LIQ_OUT_OF_MEMORY;
+
+ // histogram uses noise contrast map for importance. Color accuracy in noisy areas is not very important.
+ // noise map does not include edges to avoid ruining anti-aliasing
+ for(unsigned int row=0; row < rows; row++) {
+ bool added_ok;
+ if (all_rows_at_once) {
+ added_ok = pam_computeacolorhash(input_hist->acht, (const rgba_pixel *const *)input_image->rows, cols, rows, input_image->importance_map);
+ if (added_ok) break;
+ } else {
+ const rgba_pixel* rows_p[1] = { liq_image_get_row_rgba(input_image, row) };
+ added_ok = pam_computeacolorhash(input_hist->acht, rows_p, cols, 1, input_image->importance_map ? &input_image->importance_map[row * cols] : NULL);
+ }
+ if (!added_ok) {
+ input_hist->ignorebits++;
+ liq_verbose_printf(options, " too many colors! Scaling colors to improve clustering... %d", input_hist->ignorebits);
+ pam_freeacolorhash(input_hist->acht);
+ input_hist->acht = NULL;
+ if (liq_progress(options, options->progress_stage1 * 0.6f)) return LIQ_ABORTED;
+ break;
+ }
+ }
+ } while(!input_hist->acht);
+
+ input_hist->had_image_added = true;
+
+ liq_image_free_importance_map(input_image);
+
+ if (input_image->free_pixels && input_image->f_pixels) {
+ liq_image_free_rgba_source(input_image); // bow can free the RGBA source if copy has been made in f_pixels
+ }
+
+ return LIQ_OK;
+}
+
+LIQ_NONNULL static liq_error finalize_histogram(liq_histogram *input_hist, liq_attr *options, histogram **hist_output)
+{
+ if (liq_progress(options, options->progress_stage1 * 0.9f)) {
+ return LIQ_ABORTED;
+ }
+
+ if (!input_hist->acht) {
+ return LIQ_BITMAP_NOT_AVAILABLE;
+ }
+
+ histogram *hist = pam_acolorhashtoacolorhist(input_hist->acht, input_hist->gamma, options->malloc, options->free);
+ pam_freeacolorhash(input_hist->acht);
+ input_hist->acht = NULL;
+
+ if (!hist) {
+ return LIQ_OUT_OF_MEMORY;
+ }
+ liq_verbose_printf(options, " made histogram...%d colors found", hist->size);
+ remove_fixed_colors_from_histogram(hist, input_hist->fixed_colors_count, input_hist->fixed_colors, options->target_mse);
+
+ *hist_output = hist;
+ return LIQ_OK;
+}
+
+/**
+ Builds two maps:
+ importance_map - approximation of areas with high-frequency noise, except straight edges. 1=flat, 0=noisy.
+ edges - noise map including all edges
+ */
+LIQ_NONNULL static void contrast_maps(liq_image *image)
+{
+ const unsigned int cols = image->width, rows = image->height;
+ if (cols < 4 || rows < 4 || (3*cols*rows) > LIQ_HIGH_MEMORY_LIMIT) {
+ return;
+ }
+
+ unsigned char *restrict noise = image->importance_map ? image->importance_map : image->malloc(cols*rows);
+ image->importance_map = NULL;
+ unsigned char *restrict edges = image->edges ? image->edges : image->malloc(cols*rows);
+ image->edges = NULL;
+
+ unsigned char *restrict tmp = image->malloc(cols*rows);
+
+ if (!noise || !edges || !tmp || !liq_image_get_row_f_init(image)) {
+ image->free(noise);
+ image->free(edges);
+ image->free(tmp);
+ return;
+ }
+
+ const f_pixel *curr_row, *prev_row, *next_row;
+ curr_row = prev_row = next_row = liq_image_get_row_f(image, 0);
+
+ for (unsigned int j=0; j < rows; j++) {
+ prev_row = curr_row;
+ curr_row = next_row;
+ next_row = liq_image_get_row_f(image, MIN(rows-1,j+1));
+
+ f_pixel prev, curr = curr_row[0], next=curr;
+ for (unsigned int i=0; i < cols; i++) {
+ prev=curr;
+ curr=next;
+ next = curr_row[MIN(cols-1,i+1)];
+
+ // contrast is difference between pixels neighbouring horizontally and vertically
+ const float a = fabsf(prev.a+next.a - curr.a*2.f),
+ r = fabsf(prev.r+next.r - curr.r*2.f),
+ g = fabsf(prev.g+next.g - curr.g*2.f),
+ b = fabsf(prev.b+next.b - curr.b*2.f);
+
+ const f_pixel prevl = prev_row[i];
+ const f_pixel nextl = next_row[i];
+
+ const float a1 = fabsf(prevl.a+nextl.a - curr.a*2.f),
+ r1 = fabsf(prevl.r+nextl.r - curr.r*2.f),
+ g1 = fabsf(prevl.g+nextl.g - curr.g*2.f),
+ b1 = fabsf(prevl.b+nextl.b - curr.b*2.f);
+
+ const float horiz = MAX(MAX(a,r),MAX(g,b));
+ const float vert = MAX(MAX(a1,r1),MAX(g1,b1));
+ const float edge = MAX(horiz,vert);
+ float z = edge - fabsf(horiz-vert)*.5f;
+ z = 1.f - MAX(z,MIN(horiz,vert));
+ z *= z; // noise is amplified
+ z *= z;
+ // 85 is about 1/3rd of weight (not 0, because noisy pixels still need to be included, just not as precisely).
+ const unsigned int z_int = 80 + (unsigned int)(z * 176.f);
+ noise[j*cols+i] = MIN(z_int, 255);
+ const int e_int = 255 - (int)(edge * 256.f);
+ edges[j*cols+i] = e_int > 0 ? MIN(e_int, 255) : 0;
+ }
+ }
+
+ // noise areas are shrunk and then expanded to remove thin edges from the map
+ liq_max3(noise, tmp, cols, rows);
+ liq_max3(tmp, noise, cols, rows);
+
+ liq_blur(noise, tmp, noise, cols, rows, 3);
+
+ liq_max3(noise, tmp, cols, rows);
+
+ liq_min3(tmp, noise, cols, rows);
+ liq_min3(noise, tmp, cols, rows);
+ liq_min3(tmp, noise, cols, rows);
+
+ liq_min3(edges, tmp, cols, rows);
+ liq_max3(tmp, edges, cols, rows);
+ for(unsigned int i=0; i < cols*rows; i++) edges[i] = MIN(noise[i], edges[i]);
+
+ image->free(tmp);
+
+ image->importance_map = noise;
+ image->edges = edges;
+}
+
+/**
+ * Builds map of neighbor pixels mapped to the same palette entry
+ *
+ * For efficiency/simplicity it mainly looks for same consecutive pixels horizontally
+ * and peeks 1 pixel above/below. Full 2d algorithm doesn't improve it significantly.
+ * Correct flood fill doesn't have visually good properties.
+ */
+LIQ_NONNULL static void update_dither_map(liq_image *input_image, unsigned char *const *const row_pointers, colormap *map)
+{
+ const unsigned int width = input_image->width;
+ const unsigned int height = input_image->height;
+ unsigned char *const edges = input_image->edges;
+
+ for(unsigned int row=0; row < height; row++) {
+ unsigned char lastpixel = row_pointers[row][0];
+ unsigned int lastcol=0;
+
+ for(unsigned int col=1; col < width; col++) {
+ const unsigned char px = row_pointers[row][col];
+ if (input_image->background && map->palette[px].acolor.a < 1.f/256.f) {
+ // Transparency may or may not create an edge. When there's an explicit background set, assume no edge.
+ continue;
+ }
+
+ if (px != lastpixel || col == width-1) {
+ int neighbor_count = 10 * (col-lastcol);
+
+ unsigned int i=lastcol;
+ while(i < col) {
+ if (row > 0) {
+ unsigned char pixelabove = row_pointers[row-1][i];
+ if (pixelabove == lastpixel) neighbor_count += 15;
+ }
+ if (row < height-1) {
+ unsigned char pixelbelow = row_pointers[row+1][i];
+ if (pixelbelow == lastpixel) neighbor_count += 15;
+ }
+ i++;
+ }
+
+ while(lastcol <= col) {
+ int e = edges[row*width + lastcol];
+ edges[row*width + lastcol++] = (e+128) * (255.f/(255+128)) * (1.f - 20.f / (20 + neighbor_count));
+ }
+ lastpixel = px;
+ }
+ }
+ }
+ input_image->dither_map = input_image->edges;
+ input_image->edges = NULL;
+}
+
+/**
+ * Palette can be NULL, in which case it creates a new palette from scratch.
+ */
+static colormap *add_fixed_colors_to_palette(colormap *palette, const int max_colors, const f_pixel fixed_colors[], const int fixed_colors_count, void* (*malloc)(size_t), void (*free)(void*))
+{
+ if (!fixed_colors_count) return palette;
+
+ colormap *newpal = pam_colormap(MIN(max_colors, (palette ? palette->colors : 0) + fixed_colors_count), malloc, free);
+ unsigned int i=0;
+ if (palette && fixed_colors_count < max_colors) {
+ unsigned int palette_max = MIN(palette->colors, max_colors - fixed_colors_count);
+ for(; i < palette_max; i++) {
+ newpal->palette[i] = palette->palette[i];
+ }
+ }
+ for(int j=0; j < MIN(max_colors, fixed_colors_count); j++) {
+ newpal->palette[i++] = (colormap_item){
+ .acolor = fixed_colors[j],
+ .fixed = true,
+ };
+ }
+ if (palette) pam_freecolormap(palette);
+ return newpal;
+}
+
+LIQ_NONNULL static void adjust_histogram_callback(hist_item *item, float diff)
+{
+ item->adjusted_weight = (item->perceptual_weight + 2.0 * item->adjusted_weight) * (0.5 + diff);
+}
+
+/**
+ Repeats mediancut with different histogram weights to find palette with minimum error.
+
+ feedback_loop_trials controls how long the search will take. < 0 skips the iteration.
+ */
+static colormap *find_best_palette(histogram *hist, const liq_attr *options, const double max_mse, const f_pixel fixed_colors[], const unsigned int fixed_colors_count, double *palette_error_p)
+{
+ unsigned int max_colors = options->max_colors;
+
+ // if output is posterized it doesn't make sense to aim for perfrect colors, so increase target_mse
+ // at this point actual gamma is not set, so very conservative posterization estimate is used
+ const double target_mse = MIN(max_mse, MAX(options->target_mse, pow((1<min_posterization_output)/1024.0, 2)));
+ int feedback_loop_trials = options->feedback_loop_trials;
+ if (hist->size > 5000) {feedback_loop_trials = (feedback_loop_trials*3 + 3)/4;}
+ if (hist->size > 25000) {feedback_loop_trials = (feedback_loop_trials*3 + 3)/4;}
+ if (hist->size > 50000) {feedback_loop_trials = (feedback_loop_trials*3 + 3)/4;}
+ if (hist->size > 100000) {feedback_loop_trials = (feedback_loop_trials*3 + 3)/4;}
+ colormap *acolormap = NULL;
+ double least_error = MAX_DIFF;
+ double target_mse_overshoot = feedback_loop_trials>0 ? 1.05 : 1.0;
+ const float total_trials = (float)(feedback_loop_trials>0?feedback_loop_trials:1);
+ int fails_in_a_row=0;
+
+ do {
+ colormap *newmap;
+ if (hist->size && fixed_colors_count < max_colors) {
+ newmap = mediancut(hist, max_colors-fixed_colors_count, target_mse * target_mse_overshoot, MAX(MAX(45.0/65536.0, target_mse), least_error)*1.2,
+ options->malloc, options->free);
+ } else {
+ feedback_loop_trials = 0;
+ newmap = NULL;
+ }
+ newmap = add_fixed_colors_to_palette(newmap, max_colors, fixed_colors, fixed_colors_count, options->malloc, options->free);
+ if (!newmap) {
+ return NULL;
+ }
+
+ if (feedback_loop_trials <= 0) {
+ return newmap;
+ }
+
+ // after palette has been created, total error (MSE) is calculated to keep the best palette
+ // at the same time K-Means iteration is done to improve the palette
+ // and histogram weights are adjusted based on remapping error to give more weight to poorly matched colors
+
+ const bool first_run_of_target_mse = !acolormap && target_mse > 0;
+ double total_error = kmeans_do_iteration(hist, newmap, first_run_of_target_mse ? NULL : adjust_histogram_callback);
+
+ // goal is to increase quality or to reduce number of colors used if quality is good enough
+ if (!acolormap || total_error < least_error || (total_error <= target_mse && newmap->colors < max_colors)) {
+ if (acolormap) pam_freecolormap(acolormap);
+ acolormap = newmap;
+
+ if (total_error < target_mse && total_error > 0) {
+ // K-Means iteration improves quality above what mediancut aims for
+ // this compensates for it, making mediancut aim for worse
+ target_mse_overshoot = MIN(target_mse_overshoot*1.25, target_mse/total_error);
+ }
+
+ least_error = total_error;
+
+ // if number of colors could be reduced, try to keep it that way
+ // but allow extra color as a bit of wiggle room in case quality can be improved too
+ max_colors = MIN(newmap->colors+1, max_colors);
+
+ feedback_loop_trials -= 1; // asymptotic improvement could make it go on forever
+ fails_in_a_row = 0;
+ } else {
+ fails_in_a_row++;
+ target_mse_overshoot = 1.0;
+
+ // if error is really bad, it's unlikely to improve, so end sooner
+ feedback_loop_trials -= 5 + fails_in_a_row;
+ pam_freecolormap(newmap);
+ }
+
+ float fraction_done = 1.f-MAX(0.f, feedback_loop_trials/total_trials);
+ if (liq_progress(options, options->progress_stage1 + fraction_done * options->progress_stage2)) break;
+ liq_verbose_printf(options, " selecting colors...%d%%", (int)(100.f * fraction_done));
+ }
+ while(feedback_loop_trials > 0);
+
+ *palette_error_p = least_error;
+ return acolormap;
+}
+
+static colormap *histogram_to_palette(const histogram *hist, const liq_attr *options) {
+ if (!hist->size) {
+ return NULL;
+ }
+ colormap *acolormap = pam_colormap(hist->size, options->malloc, options->free);
+ for(unsigned int i=0; i < hist->size; i++) {
+ acolormap->palette[i].acolor = hist->achv[i].acolor;
+ acolormap->palette[i].popularity = hist->achv[i].perceptual_weight;
+ }
+ return acolormap;
+}
+
+LIQ_NONNULL static liq_error pngquant_quantize(histogram *hist, const liq_attr *options, const int fixed_colors_count, const f_pixel fixed_colors[], const double gamma, bool fixed_result_colors, liq_result **result_output)
+{
+ colormap *acolormap;
+ double palette_error = -1;
+
+ assert((verbose_print(options, "SLOW debug checks enabled. Recompile with NDEBUG for normal operation."),1));
+
+ const bool few_input_colors = hist->size+fixed_colors_count <= options->max_colors;
+
+ if (liq_progress(options, options->progress_stage1)) return LIQ_ABORTED;
+
+ // If image has few colors to begin with (and no quality degradation is required)
+ // then it's possible to skip quantization entirely
+ if (few_input_colors && options->target_mse == 0) {
+ acolormap = add_fixed_colors_to_palette(histogram_to_palette(hist, options), options->max_colors, fixed_colors, fixed_colors_count, options->malloc, options->free);
+ palette_error = 0;
+ } else {
+ const double max_mse = options->max_mse * (few_input_colors ? 0.33 : 1.0); // when degrading image that's already paletted, require much higher improvement, since pal2pal often looks bad and there's little gain
+ acolormap = find_best_palette(hist, options, max_mse, fixed_colors, fixed_colors_count, &palette_error);
+ if (!acolormap) {
+ return LIQ_VALUE_OUT_OF_RANGE;
+ }
+
+ // K-Means iteration approaches local minimum for the palette
+ double iteration_limit = options->kmeans_iteration_limit;
+ unsigned int iterations = options->kmeans_iterations;
+
+ if (!iterations && palette_error < 0 && max_mse < MAX_DIFF) iterations = 1; // otherwise total error is never calculated and MSE limit won't work
+
+ if (iterations) {
+ // likely_colormap_index (used and set in kmeans_do_iteration) can't point to index outside colormap
+ if (acolormap->colors < 256) for(unsigned int j=0; j < hist->size; j++) {
+ if (hist->achv[j].tmp.likely_colormap_index >= acolormap->colors) {
+ hist->achv[j].tmp.likely_colormap_index = 0; // actual value doesn't matter, as the guess is out of date anyway
+ }
+ }
+
+ if (hist->size > 5000) {iterations = (iterations*3 + 3)/4;}
+ if (hist->size > 25000) {iterations = (iterations*3 + 3)/4;}
+ if (hist->size > 50000) {iterations = (iterations*3 + 3)/4;}
+ if (hist->size > 100000) {iterations = (iterations*3 + 3)/4; iteration_limit *= 2;}
+
+ verbose_print(options, " moving colormap towards local minimum");
+
+ double previous_palette_error = MAX_DIFF;
+
+ for(unsigned int i=0; i < iterations; i++) {
+ palette_error = kmeans_do_iteration(hist, acolormap, NULL);
+
+ if (liq_progress(options, options->progress_stage1 + options->progress_stage2 + (i * options->progress_stage3 * 0.9f) / iterations)) {
+ break;
+ }
+
+ if (fabs(previous_palette_error-palette_error) < iteration_limit) {
+ break;
+ }
+
+ if (palette_error > max_mse*1.5) { // probably hopeless
+ if (palette_error > max_mse*3.0) break; // definitely hopeless
+ i++;
+ }
+
+ previous_palette_error = palette_error;
+ }
+ }
+
+ if (palette_error > max_mse) {
+ liq_verbose_printf(options, " image degradation MSE=%.3f (Q=%d) exceeded limit of %.3f (%d)",
+ mse_to_standard_mse(palette_error), mse_to_quality(palette_error),
+ mse_to_standard_mse(max_mse), mse_to_quality(max_mse));
+ pam_freecolormap(acolormap);
+ return LIQ_QUALITY_TOO_LOW;
+ }
+ }
+
+ if (liq_progress(options, options->progress_stage1 + options->progress_stage2 + options->progress_stage3 * 0.95f)) {
+ pam_freecolormap(acolormap);
+ return LIQ_ABORTED;
+ }
+
+ sort_palette(acolormap, options);
+
+ // If palette was created from a multi-image histogram,
+ // then it shouldn't be optimized for one image during remapping
+ if (fixed_result_colors) {
+ for(unsigned int i=0; i < acolormap->colors; i++) {
+ acolormap->palette[i].fixed = true;
+ }
+ }
+
+ liq_result *result = options->malloc(sizeof(liq_result));
+ if (!result) return LIQ_OUT_OF_MEMORY;
+ *result = (liq_result){
+ .magic_header = liq_result_magic,
+ .malloc = options->malloc,
+ .free = options->free,
+ .palette = acolormap,
+ .palette_error = palette_error,
+ .use_dither_map = options->use_dither_map,
+ .gamma = gamma,
+ .min_posterization_output = options->min_posterization_output,
+ };
+ *result_output = result;
+ return LIQ_OK;
+}
+
+LIQ_EXPORT LIQ_NONNULL liq_error liq_write_remapped_image(liq_result *result, liq_image *input_image, void *buffer, size_t buffer_size)
+{
+ if (!CHECK_STRUCT_TYPE(result, liq_result)) {
+ return LIQ_INVALID_POINTER;
+ }
+ if (!CHECK_STRUCT_TYPE(input_image, liq_image)) {
+ return LIQ_INVALID_POINTER;
+ }
+ if (!CHECK_USER_POINTER(buffer)) {
+ return LIQ_INVALID_POINTER;
+ }
+
+ const size_t required_size = (size_t)input_image->width * (size_t)input_image->height;
+ if (buffer_size < required_size) {
+ return LIQ_BUFFER_TOO_SMALL;
+ }
+
+ unsigned char **rows = input_image->malloc(input_image->height * sizeof(unsigned char *));
+ unsigned char *buffer_bytes = buffer;
+ for(unsigned int i=0; i < input_image->height; i++) {
+ rows[i] = &buffer_bytes[input_image->width * i];
+ }
+
+ liq_error err = liq_write_remapped_image_rows(result, input_image, rows);
+ input_image->free(rows);
+ return err;
+}
+
+LIQ_EXPORT LIQ_NONNULL liq_error liq_write_remapped_image_rows(liq_result *quant, liq_image *input_image, unsigned char **row_pointers)
+{
+ if (!CHECK_STRUCT_TYPE(quant, liq_result)) return LIQ_INVALID_POINTER;
+ if (!CHECK_STRUCT_TYPE(input_image, liq_image)) return LIQ_INVALID_POINTER;
+ for(unsigned int i=0; i < input_image->height; i++) {
+ if (!CHECK_USER_POINTER(row_pointers+i) || !CHECK_USER_POINTER(row_pointers[i])) return LIQ_INVALID_POINTER;
+ }
+
+ if (quant->remapping) {
+ liq_remapping_result_destroy(quant->remapping);
+ }
+ liq_remapping_result *const result = quant->remapping = liq_remapping_result_create(quant);
+ if (!result) return LIQ_OUT_OF_MEMORY;
+
+ if (!input_image->edges && !input_image->dither_map && quant->use_dither_map) {
+ contrast_maps(input_image);
+ }
+
+ if (liq_remap_progress(result, result->progress_stage1 * 0.25f)) {
+ return LIQ_ABORTED;
+ }
+
+ /*
+ ** Step 4: map the colors in the image to their closest match in the
+ ** new colormap, and write 'em out.
+ */
+
+ float remapping_error = result->palette_error;
+ if (result->dither_level == 0) {
+ set_rounded_palette(&result->int_palette, result->palette, result->gamma, quant->min_posterization_output);
+ remapping_error = remap_to_palette(input_image, row_pointers, result->palette);
+ } else {
+ const bool is_image_huge = (input_image->width * input_image->height) > 2000 * 2000;
+ const bool allow_dither_map = result->use_dither_map == 2 || (!is_image_huge && result->use_dither_map);
+ const bool generate_dither_map = allow_dither_map && (input_image->edges && !input_image->dither_map);
+ if (generate_dither_map) {
+ // If dithering (with dither map) is required, this image is used to find areas that require dithering
+ remapping_error = remap_to_palette(input_image, row_pointers, result->palette);
+ update_dither_map(input_image, row_pointers, result->palette);
+ }
+
+ if (liq_remap_progress(result, result->progress_stage1 * 0.5f)) {
+ return LIQ_ABORTED;
+ }
+
+ // remapping above was the last chance to do K-Means iteration, hence the final palette is set after remapping
+ set_rounded_palette(&result->int_palette, result->palette, result->gamma, quant->min_posterization_output);
+
+ if (!remap_to_palette_floyd(input_image, row_pointers, result, MAX(remapping_error*2.4, 8.f/256.f), generate_dither_map)) {
+ return LIQ_ABORTED;
+ }
+ }
+
+ // remapping error from dithered image is absurd, so always non-dithered value is used
+ // palette_error includes some perceptual weighting from histogram which is closer correlated with dssim
+ // so that should be used when possible.
+ if (result->palette_error < 0) {
+ result->palette_error = remapping_error;
+ }
+
+ return LIQ_OK;
+}
+
+LIQ_EXPORT int liq_version() {
+ return LIQ_VERSION;
+}
diff --git a/libs/imagequant/external/libimagequant/libimagequant.cs b/libs/imagequant/external/libimagequant/libimagequant.cs
new file mode 100644
index 00000000..98ee53ed
--- /dev/null
+++ b/libs/imagequant/external/libimagequant/libimagequant.cs
@@ -0,0 +1,164 @@
+/*
+This is an example demonstrating use of libimagequant from C#.
+
+This example code can be freely copied under CC0 (public domain) license.
+*/
+
+using System;
+using System.Collections.Generic;
+using System.Runtime.InteropServices;
+
+[StructLayout(LayoutKind.Sequential)]
+struct liq_color
+{
+ public byte r, g, b, a;
+};
+
+[StructLayout(LayoutKind.Sequential)]
+struct liq_palette
+{
+ public int count;
+ [MarshalAs(UnmanagedType.ByValArray, SizeConst = 256)]
+ public liq_color[] entries;
+};
+
+enum liq_error
+{
+ LIQ_OK = 0,
+ LIQ_QUALITY_TOO_LOW = 99,
+ LIQ_VALUE_OUT_OF_RANGE = 100,
+ LIQ_OUT_OF_MEMORY,
+ LIQ_ABORTED,
+ LIQ_BITMAP_NOT_AVAILABLE,
+ LIQ_BUFFER_TOO_SMALL,
+ LIQ_INVALID_POINTER,
+};
+
+namespace liq
+{
+ using liq_attr_ptr = IntPtr;
+ using liq_image_ptr = IntPtr;
+ using liq_result_ptr = IntPtr;
+ using size_t = UIntPtr;
+
+ class Liq
+ {
+ [DllImport(@"imagequant.dll")]
+ public static extern liq_attr_ptr liq_attr_create();
+ [DllImport(@"imagequant.dll")]
+ public static extern liq_attr_ptr liq_attr_copy(liq_attr_ptr attr);
+ [DllImport(@"imagequant.dll")]
+ public static extern void liq_attr_destroy(liq_attr_ptr attr);
+
+ [DllImport(@"imagequant.dll")]
+ public static extern liq_error liq_set_max_colors(liq_attr_ptr attr, int colors);
+ [DllImport(@"imagequant.dll")]
+ public static extern int liq_get_max_colors(liq_attr_ptr attr);
+ [DllImport(@"imagequant.dll")]
+ public static extern liq_error liq_set_speed(liq_attr_ptr attr, int speed);
+ [DllImport(@"imagequant.dll")]
+ public static extern int liq_get_speed(liq_attr_ptr attr);
+ [DllImport(@"imagequant.dll")]
+ public static extern liq_error liq_set_min_opacity(liq_attr_ptr attr, int min);
+ [DllImport(@"imagequant.dll")]
+ public static extern int liq_get_min_opacity(liq_attr_ptr attr);
+ [DllImport(@"imagequant.dll")]
+ public static extern liq_error liq_set_min_posterization(liq_attr_ptr attr, int bits);
+ [DllImport(@"imagequant.dll")]
+ public static extern int liq_get_min_posterization(liq_attr_ptr attr);
+ [DllImport(@"imagequant.dll")]
+ public static extern liq_error liq_set_quality(liq_attr_ptr attr, int minimum, int maximum);
+ [DllImport(@"imagequant.dll")]
+ public static extern int liq_get_min_quality(liq_attr_ptr attr);
+ [DllImport(@"imagequant.dll")]
+ public static extern int liq_get_max_quality(liq_attr_ptr attr);
+ [DllImport(@"imagequant.dll")]
+ public static extern void liq_set_last_index_transparent(liq_attr_ptr attr, int is_last);
+
+ [DllImport(@"imagequant.dll")]
+ public static extern liq_image_ptr liq_image_create_rgba(liq_attr_ptr attr, [In, MarshalAs(UnmanagedType.LPArray)] byte[] bitmap, int width, int height, double gamma);
+
+ [DllImport(@"imagequant.dll")]
+ public static extern liq_error liq_image_set_memory_ownership(liq_image_ptr image, int ownership_flags);
+ [DllImport(@"imagequant.dll")]
+ public static extern liq_error liq_image_add_fixed_color(liq_image_ptr img, liq_color color);
+ [DllImport(@"imagequant.dll")]
+ public static extern int liq_image_get_width(liq_image_ptr img);
+ [DllImport(@"imagequant.dll")]
+ public static extern int liq_image_get_height(liq_image_ptr img);
+ [DllImport(@"imagequant.dll")]
+ public static extern void liq_image_destroy(liq_image_ptr img);
+
+ [DllImport(@"imagequant.dll")]
+ public static extern liq_result_ptr liq_quantize_image(liq_attr_ptr attr, liq_image_ptr input_image);
+
+ [DllImport(@"imagequant.dll")]
+ public static extern liq_error liq_set_dithering_level(liq_result_ptr res, float dither_level);
+ [DllImport(@"imagequant.dll")]
+ public static extern liq_error liq_set_output_gamma(liq_result_ptr res, double gamma);
+ [DllImport(@"imagequant.dll")]
+ public static extern double liq_get_output_gamma(liq_result_ptr res);
+
+ [DllImport(@"imagequant.dll")]
+ public static extern IntPtr liq_get_palette(liq_result_ptr res);
+
+ [DllImport(@"imagequant.dll")]
+ public static extern liq_error liq_write_remapped_image(liq_result_ptr res, liq_image_ptr input_image, [Out, MarshalAs(UnmanagedType.LPArray)] byte[] buffer, size_t buffer_size);
+
+ [DllImport(@"imagequant.dll")]
+ public static extern double liq_get_quantization_error(liq_result_ptr res);
+ [DllImport(@"imagequant.dll")]
+ public static extern int liq_get_quantization_quality(liq_result_ptr res);
+ [DllImport(@"imagequant.dll")]
+ public static extern double liq_get_remapping_error(liq_result_ptr res);
+ [DllImport(@"imagequant.dll")]
+ public static extern int liq_get_remapping_quality(liq_result_ptr res);
+
+ [DllImport(@"imagequant.dll")]
+ public static extern void liq_result_destroy(liq_result_ptr res);
+
+ [DllImport(@"imagequant.dll")]
+ public static extern int liq_version();
+
+ static void Main(string[] args)
+ {
+ Console.WriteLine("library version: {0}", liq_version());
+
+ int width = 3;
+ int height = 1;
+
+ var attr = liq_attr_create();
+ if (attr == IntPtr.Zero) throw new Exception("can't create attr");
+
+ byte[] bitmap = { // R, G, B, A, R, G, B, A, ...
+ 111, 222, 33, 255,
+ 255, 0, 255, 255,
+ 255, 0, 255, 255,
+ };
+ var img = liq_image_create_rgba(attr, bitmap, width, height, 0);
+ if (img == IntPtr.Zero) throw new Exception("can't create image");
+
+ var res = liq_quantize_image(attr, img);
+ if (res == IntPtr.Zero) throw new Exception("can't quantize image");
+
+ var buffer_size = width * height;
+ var remapped = new byte[buffer_size];
+
+ var err = liq_write_remapped_image(res, img, remapped, (UIntPtr)buffer_size);
+ if (err != liq_error.LIQ_OK)
+ {
+ throw new Exception("remapping error");
+ }
+
+ Console.WriteLine("first pixel is {0}th palette entry", remapped[0]);
+
+ liq_palette pal = (liq_palette)Marshal.PtrToStructure(liq_get_palette(res), typeof(liq_palette));
+
+ Console.WriteLine("palette entries: {0}; red of first entry: {1}", pal.count, pal.entries[0].r);
+
+ liq_image_destroy(img);
+ liq_result_destroy(res);
+ liq_attr_destroy(attr);
+ }
+ }
+}
diff --git a/libs/imagequant/external/libimagequant/libimagequant.h b/libs/imagequant/external/libimagequant/libimagequant.h
new file mode 100644
index 00000000..99967efd
--- /dev/null
+++ b/libs/imagequant/external/libimagequant/libimagequant.h
@@ -0,0 +1,151 @@
+/*
+ * https://pngquant.org
+ */
+
+#ifndef LIBIMAGEQUANT_H
+#define LIBIMAGEQUANT_H
+
+#ifdef IMAGEQUANT_EXPORTS
+#define LIQ_EXPORT __declspec(dllexport)
+#endif
+
+#ifndef LIQ_EXPORT
+#define LIQ_EXPORT extern
+#endif
+
+#define LIQ_VERSION 21600
+#define LIQ_VERSION_STRING "2.17.0"
+
+#ifndef LIQ_PRIVATE
+#if defined(__GNUC__) || defined (__llvm__)
+#define LIQ_PRIVATE __attribute__((visibility("hidden")))
+#define LIQ_NONNULL __attribute__((nonnull))
+#define LIQ_USERESULT __attribute__((warn_unused_result))
+#else
+#define LIQ_PRIVATE
+#define LIQ_NONNULL
+#define LIQ_USERESULT
+#endif
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include
+
+typedef struct liq_attr liq_attr;
+typedef struct liq_image liq_image;
+typedef struct liq_result liq_result;
+typedef struct liq_histogram liq_histogram;
+
+typedef struct liq_color {
+ unsigned char r, g, b, a;
+} liq_color;
+
+typedef struct liq_palette {
+ unsigned int count;
+ liq_color entries[256];
+} liq_palette;
+
+typedef enum liq_error {
+ LIQ_OK = 0,
+ LIQ_QUALITY_TOO_LOW = 99,
+ LIQ_VALUE_OUT_OF_RANGE = 100,
+ LIQ_OUT_OF_MEMORY,
+ LIQ_ABORTED,
+ LIQ_BITMAP_NOT_AVAILABLE,
+ LIQ_BUFFER_TOO_SMALL,
+ LIQ_INVALID_POINTER,
+ LIQ_UNSUPPORTED,
+} liq_error;
+
+enum liq_ownership {
+ LIQ_OWN_ROWS=4,
+ LIQ_OWN_PIXELS=8,
+ LIQ_COPY_PIXELS=16,
+};
+
+typedef struct liq_histogram_entry {
+ liq_color color;
+ unsigned int count;
+} liq_histogram_entry;
+
+LIQ_EXPORT LIQ_USERESULT liq_attr* liq_attr_create(void);
+LIQ_EXPORT LIQ_USERESULT liq_attr* liq_attr_create_with_allocator(void* (*malloc)(size_t), void (*free)(void*));
+LIQ_EXPORT LIQ_USERESULT liq_attr* liq_attr_copy(const liq_attr *orig) LIQ_NONNULL;
+LIQ_EXPORT void liq_attr_destroy(liq_attr *attr) LIQ_NONNULL;
+
+LIQ_EXPORT LIQ_USERESULT liq_histogram* liq_histogram_create(const liq_attr* attr);
+LIQ_EXPORT liq_error liq_histogram_add_image(liq_histogram *hist, const liq_attr *attr, liq_image* image) LIQ_NONNULL;
+LIQ_EXPORT liq_error liq_histogram_add_colors(liq_histogram *hist, const liq_attr *attr, const liq_histogram_entry entries[], int num_entries, double gamma) LIQ_NONNULL;
+LIQ_EXPORT liq_error liq_histogram_add_fixed_color(liq_histogram *hist, liq_color color, double gamma) LIQ_NONNULL;
+LIQ_EXPORT void liq_histogram_destroy(liq_histogram *hist) LIQ_NONNULL;
+
+LIQ_EXPORT liq_error liq_set_max_colors(liq_attr* attr, int colors) LIQ_NONNULL;
+LIQ_EXPORT LIQ_USERESULT int liq_get_max_colors(const liq_attr* attr) LIQ_NONNULL;
+LIQ_EXPORT liq_error liq_set_speed(liq_attr* attr, int speed) LIQ_NONNULL;
+LIQ_EXPORT LIQ_USERESULT int liq_get_speed(const liq_attr* attr) LIQ_NONNULL;
+LIQ_EXPORT liq_error liq_set_min_opacity(liq_attr* attr, int min) LIQ_NONNULL;
+LIQ_EXPORT LIQ_USERESULT int liq_get_min_opacity(const liq_attr* attr) LIQ_NONNULL;
+LIQ_EXPORT liq_error liq_set_min_posterization(liq_attr* attr, int bits) LIQ_NONNULL;
+LIQ_EXPORT LIQ_USERESULT int liq_get_min_posterization(const liq_attr* attr) LIQ_NONNULL;
+LIQ_EXPORT liq_error liq_set_quality(liq_attr* attr, int minimum, int maximum) LIQ_NONNULL;
+LIQ_EXPORT LIQ_USERESULT int liq_get_min_quality(const liq_attr* attr) LIQ_NONNULL;
+LIQ_EXPORT LIQ_USERESULT int liq_get_max_quality(const liq_attr* attr) LIQ_NONNULL;
+LIQ_EXPORT void liq_set_last_index_transparent(liq_attr* attr, int is_last) LIQ_NONNULL;
+
+typedef void liq_log_callback_function(const liq_attr*, const char *message, void* user_info);
+typedef void liq_log_flush_callback_function(const liq_attr*, void* user_info);
+LIQ_EXPORT void liq_set_log_callback(liq_attr*, liq_log_callback_function*, void* user_info);
+LIQ_EXPORT void liq_set_log_flush_callback(liq_attr*, liq_log_flush_callback_function*, void* user_info);
+
+typedef int liq_progress_callback_function(float progress_percent, void* user_info);
+LIQ_EXPORT void liq_attr_set_progress_callback(liq_attr*, liq_progress_callback_function*, void* user_info);
+LIQ_EXPORT void liq_result_set_progress_callback(liq_result*, liq_progress_callback_function*, void* user_info);
+
+// The rows and their data are not modified. The type of `rows` is non-const only due to a bug in C's typesystem design.
+LIQ_EXPORT LIQ_USERESULT liq_image *liq_image_create_rgba_rows(const liq_attr *attr, void *const rows[], int width, int height, double gamma) LIQ_NONNULL;
+LIQ_EXPORT LIQ_USERESULT liq_image *liq_image_create_rgba(const liq_attr *attr, const void *bitmap, int width, int height, double gamma) LIQ_NONNULL;
+
+typedef void liq_image_get_rgba_row_callback(liq_color row_out[], int row, int width, void* user_info);
+LIQ_EXPORT LIQ_USERESULT liq_image *liq_image_create_custom(const liq_attr *attr, liq_image_get_rgba_row_callback *row_callback, void* user_info, int width, int height, double gamma);
+
+LIQ_EXPORT liq_error liq_image_set_memory_ownership(liq_image *image, int ownership_flags) LIQ_NONNULL;
+LIQ_EXPORT liq_error liq_image_set_background(liq_image *img, liq_image *background_image) LIQ_NONNULL;
+LIQ_EXPORT liq_error liq_image_set_importance_map(liq_image *img, unsigned char buffer[], size_t buffer_size, enum liq_ownership memory_handling) LIQ_NONNULL;
+LIQ_EXPORT liq_error liq_image_add_fixed_color(liq_image *img, liq_color color) LIQ_NONNULL;
+LIQ_EXPORT LIQ_USERESULT int liq_image_get_width(const liq_image *img) LIQ_NONNULL;
+LIQ_EXPORT LIQ_USERESULT int liq_image_get_height(const liq_image *img) LIQ_NONNULL;
+LIQ_EXPORT void liq_image_destroy(liq_image *img) LIQ_NONNULL;
+
+LIQ_EXPORT LIQ_USERESULT liq_error liq_histogram_quantize(liq_histogram *const input_hist, liq_attr *const options, liq_result **result_output) LIQ_NONNULL;
+LIQ_EXPORT LIQ_USERESULT liq_error liq_image_quantize(liq_image *const input_image, liq_attr *const options, liq_result **result_output) LIQ_NONNULL;
+
+LIQ_EXPORT liq_error liq_set_dithering_level(liq_result *res, float dither_level) LIQ_NONNULL;
+LIQ_EXPORT liq_error liq_set_output_gamma(liq_result* res, double gamma) LIQ_NONNULL;
+LIQ_EXPORT LIQ_USERESULT double liq_get_output_gamma(const liq_result *result) LIQ_NONNULL;
+
+LIQ_EXPORT LIQ_USERESULT const liq_palette *liq_get_palette(liq_result *result) LIQ_NONNULL;
+
+LIQ_EXPORT liq_error liq_write_remapped_image(liq_result *result, liq_image *input_image, void *buffer, size_t buffer_size) LIQ_NONNULL;
+LIQ_EXPORT liq_error liq_write_remapped_image_rows(liq_result *result, liq_image *input_image, unsigned char **row_pointers) LIQ_NONNULL;
+
+LIQ_EXPORT double liq_get_quantization_error(const liq_result *result) LIQ_NONNULL;
+LIQ_EXPORT int liq_get_quantization_quality(const liq_result *result) LIQ_NONNULL;
+LIQ_EXPORT double liq_get_remapping_error(const liq_result *result) LIQ_NONNULL;
+LIQ_EXPORT int liq_get_remapping_quality(const liq_result *result) LIQ_NONNULL;
+
+LIQ_EXPORT void liq_result_destroy(liq_result *) LIQ_NONNULL;
+
+LIQ_EXPORT int liq_version(void);
+
+
+// Deprecated
+LIQ_EXPORT LIQ_USERESULT liq_result *liq_quantize_image(liq_attr *options, liq_image *input_image) LIQ_NONNULL;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/libs/imagequant/external/libimagequant/mediancut.c b/libs/imagequant/external/libimagequant/mediancut.c
new file mode 100644
index 00000000..2df79419
--- /dev/null
+++ b/libs/imagequant/external/libimagequant/mediancut.c
@@ -0,0 +1,465 @@
+/*
+** © 2009-2018 by Kornel Lesiński.
+** © 1989, 1991 by Jef Poskanzer.
+** © 1997, 2000, 2002 by Greg Roelofs; based on an idea by Stefan Schneider.
+**
+** See COPYRIGHT file for license.
+*/
+
+#include
+#include
+
+#include "libimagequant.h"
+#include "pam.h"
+#include "mediancut.h"
+
+#define index_of_channel(ch) (offsetof(f_pixel,ch)/sizeof(float))
+
+static f_pixel averagepixels(unsigned int clrs, const hist_item achv[]);
+
+struct box {
+ f_pixel color;
+ f_pixel variance;
+ double sum, total_error, max_error;
+ unsigned int ind;
+ unsigned int colors;
+};
+
+ALWAYS_INLINE static double variance_diff(double val, const double good_enough);
+inline static double variance_diff(double val, const double good_enough)
+{
+ val *= val;
+ if (val < good_enough*good_enough) return val*0.25;
+ return val;
+}
+
+/** Weighted per-channel variance of the box. It's used to decide which channel to split by */
+static f_pixel box_variance(const hist_item achv[], const struct box *box)
+{
+ f_pixel mean = box->color;
+ double variancea=0, variancer=0, varianceg=0, varianceb=0;
+
+ for(unsigned int i = 0; i < box->colors; ++i) {
+ const f_pixel px = achv[box->ind + i].acolor;
+ double weight = achv[box->ind + i].adjusted_weight;
+ variancea += variance_diff(mean.a - px.a, 2.0/256.0)*weight;
+ variancer += variance_diff(mean.r - px.r, 1.0/256.0)*weight;
+ varianceg += variance_diff(mean.g - px.g, 1.0/256.0)*weight;
+ varianceb += variance_diff(mean.b - px.b, 1.0/256.0)*weight;
+ }
+
+ return (f_pixel){
+ .a = variancea*(4.0/16.0),
+ .r = variancer*(7.0/16.0),
+ .g = varianceg*(9.0/16.0),
+ .b = varianceb*(5.0/16.0),
+ };
+}
+
+static double box_max_error(const hist_item achv[], const struct box *box)
+{
+ f_pixel mean = box->color;
+ double max_error = 0;
+
+ for(unsigned int i = 0; i < box->colors; ++i) {
+ const double diff = colordifference(mean, achv[box->ind + i].acolor);
+ if (diff > max_error) {
+ max_error = diff;
+ }
+ }
+ return max_error;
+}
+
+ALWAYS_INLINE static double color_weight(f_pixel median, hist_item h);
+
+static inline void hist_item_swap(hist_item *l, hist_item *r)
+{
+ if (l != r) {
+ hist_item t = *l;
+ *l = *r;
+ *r = t;
+ }
+}
+
+ALWAYS_INLINE static unsigned int qsort_pivot(const hist_item *const base, const unsigned int len);
+inline static unsigned int qsort_pivot(const hist_item *const base, const unsigned int len)
+{
+ if (len < 32) {
+ return len/2;
+ }
+
+ const unsigned int aidx=8, bidx=len/2, cidx=len-1;
+ const unsigned int a=base[aidx].tmp.sort_value, b=base[bidx].tmp.sort_value, c=base[cidx].tmp.sort_value;
+ return (a < b) ? ((b < c) ? bidx : ((a < c) ? cidx : aidx ))
+ : ((b > c) ? bidx : ((a < c) ? aidx : cidx ));
+}
+
+ALWAYS_INLINE static unsigned int qsort_partition(hist_item *const base, const unsigned int len);
+inline static unsigned int qsort_partition(hist_item *const base, const unsigned int len)
+{
+ unsigned int l = 1, r = len;
+ if (len >= 8) {
+ hist_item_swap(&base[0], &base[qsort_pivot(base,len)]);
+ }
+
+ const unsigned int pivot_value = base[0].tmp.sort_value;
+ while (l < r) {
+ if (base[l].tmp.sort_value >= pivot_value) {
+ l++;
+ } else {
+ while(l < --r && base[r].tmp.sort_value <= pivot_value) {}
+ hist_item_swap(&base[l], &base[r]);
+ }
+ }
+ l--;
+ hist_item_swap(&base[0], &base[l]);
+
+ return l;
+}
+
+/** quick select algorithm */
+static void hist_item_sort_range(hist_item base[], unsigned int len, unsigned int sort_start)
+{
+ for(;;) {
+ const unsigned int l = qsort_partition(base, len), r = l+1;
+
+ if (l > 0 && sort_start < l) {
+ len = l;
+ }
+ else if (r < len && sort_start > r) {
+ base += r; len -= r; sort_start -= r;
+ }
+ else break;
+ }
+}
+
+/** sorts array to make sum of weights lower than halfvar one side, returns index of the edge between halfvar parts of the set */
+static unsigned int hist_item_sort_halfvar(hist_item base[], unsigned int len, double halfvar)
+{
+ unsigned int base_idx = 0; // track base-index
+ do {
+ const unsigned int l = qsort_partition(base, len), r = l+1;
+
+ // check if sum of left side is smaller than half,
+ // if it is, then it doesn't need to be sorted
+ double tmpsum = 0.;
+ for(unsigned int t = 0; t <= l && tmpsum < halfvar; ++t) tmpsum += base[t].color_weight;
+
+ // the split is on the left part
+ if (tmpsum >= halfvar) {
+ if (l > 0) {
+ len = l;
+ continue;
+ } else {
+ // reached the end of left part
+ return base_idx;
+ }
+ }
+ // process the right part
+ halfvar -= tmpsum;
+ if (len > r) {
+ base += r;
+ base_idx += r;
+ len -= r; // tail-recursive "call"
+ } else {
+ // reached the end of the right part
+ return base_idx + len;
+ }
+ } while(1);
+}
+
+static f_pixel get_median(const struct box *b, hist_item achv[]);
+
+typedef struct {
+ unsigned int chan; float variance;
+} channelvariance;
+
+static int comparevariance(const void *ch1, const void *ch2)
+{
+ return ((const channelvariance*)ch1)->variance > ((const channelvariance*)ch2)->variance ? -1 :
+ (((const channelvariance*)ch1)->variance < ((const channelvariance*)ch2)->variance ? 1 : 0);
+}
+
+/** Finds which channels need to be sorted first and preproceses achv for fast sort */
+static double prepare_sort(struct box *b, hist_item achv[])
+{
+ /*
+ ** Sort dimensions by their variance, and then sort colors first by dimension with highest variance
+ */
+ channelvariance channels[4] = {
+ {index_of_channel(a), b->variance.a},
+ {index_of_channel(r), b->variance.r},
+ {index_of_channel(g), b->variance.g},
+ {index_of_channel(b), b->variance.b},
+ };
+
+ qsort(channels, 4, sizeof(channels[0]), comparevariance);
+
+ const unsigned int ind1 = b->ind;
+ const unsigned int colors = b->colors;
+#if __GNUC__ >= 9 || __clang__
+ #pragma omp parallel for if (colors > 25000) \
+ schedule(static) default(none) shared(achv, channels, colors, ind1)
+#else
+ #pragma omp parallel for if (colors > 25000) \
+ schedule(static) default(none) shared(achv, channels)
+#endif
+ for(unsigned int i=0; i < colors; i++) {
+ const float *chans = (const float *)&achv[ind1 + i].acolor;
+ // Only the first channel really matters. When trying median cut many times
+ // with different histogram weights, I don't want sort randomness to influence outcome.
+ achv[ind1 + i].tmp.sort_value = ((unsigned int)(chans[channels[0].chan]*65535.0)<<16) |
+ (unsigned int)((chans[channels[2].chan] + chans[channels[1].chan]/2.0 + chans[channels[3].chan]/4.0)*65535.0);
+ }
+
+ const f_pixel median = get_median(b, achv);
+
+ // box will be split to make color_weight of each side even
+ const unsigned int ind = b->ind, end = ind+b->colors;
+ double totalvar = 0;
+ #pragma omp parallel for if (end - ind > 15000) \
+ schedule(static) default(shared) reduction(+:totalvar)
+ for(unsigned int j=ind; j < end; j++) totalvar += (achv[j].color_weight = color_weight(median, achv[j]));
+ return totalvar / 2.0;
+}
+
+/** finds median in unsorted set by sorting only minimum required */
+static f_pixel get_median(const struct box *b, hist_item achv[])
+{
+ const unsigned int median_start = (b->colors-1)/2;
+
+ hist_item_sort_range(&(achv[b->ind]), b->colors,
+ median_start);
+
+ if (b->colors&1) return achv[b->ind + median_start].acolor;
+
+ // technically the second color is not guaranteed to be sorted correctly
+ // but most of the time it is good enough to be useful
+ return averagepixels(2, &achv[b->ind + median_start]);
+}
+
+/*
+ ** Find the best splittable box. -1 if no boxes are splittable.
+ */
+static int best_splittable_box(struct box bv[], unsigned int boxes, const double max_mse)
+{
+ int bi=-1; double maxsum=0;
+ for(unsigned int i=0; i < boxes; i++) {
+ if (bv[i].colors < 2) {
+ continue;
+ }
+
+ // looks only at max variance, because it's only going to split by it
+ const double cv = MAX(bv[i].variance.r, MAX(bv[i].variance.g,bv[i].variance.b));
+ double thissum = bv[i].sum * MAX(bv[i].variance.a, cv);
+
+ if (bv[i].max_error > max_mse) {
+ thissum = thissum* bv[i].max_error/max_mse;
+ }
+
+ if (thissum > maxsum) {
+ maxsum = thissum;
+ bi = i;
+ }
+ }
+ return bi;
+}
+
+inline static double color_weight(f_pixel median, hist_item h)
+{
+ float diff = colordifference(median, h.acolor);
+ return sqrt(diff) * (sqrt(1.0+h.adjusted_weight)-1.0);
+}
+
+static void set_colormap_from_boxes(colormap *map, struct box bv[], unsigned int boxes, hist_item *achv);
+static void adjust_histogram(hist_item *achv, const struct box bv[], unsigned int boxes);
+
+static double box_error(const struct box *box, const hist_item achv[])
+{
+ f_pixel avg = box->color;
+
+ double total_error=0;
+ for (unsigned int i = 0; i < box->colors; ++i) {
+ total_error += colordifference(avg, achv[box->ind + i].acolor) * achv[box->ind + i].perceptual_weight;
+ }
+
+ return total_error;
+}
+
+
+static bool total_box_error_below_target(double target_mse, struct box bv[], unsigned int boxes, const histogram *hist)
+{
+ target_mse *= hist->total_perceptual_weight;
+ double total_error=0;
+
+ for(unsigned int i=0; i < boxes; i++) {
+ // error is (re)calculated lazily
+ if (bv[i].total_error >= 0) {
+ total_error += bv[i].total_error;
+ }
+ if (total_error > target_mse) return false;
+ }
+
+ for(unsigned int i=0; i < boxes; i++) {
+ if (bv[i].total_error < 0) {
+ bv[i].total_error = box_error(&bv[i], hist->achv);
+ total_error += bv[i].total_error;
+ }
+ if (total_error > target_mse) return false;
+ }
+
+ return true;
+}
+
+static void box_init(struct box *box, const hist_item *achv, const unsigned int ind, const unsigned int colors, const double sum) {
+ box->ind = ind;
+ box->colors = colors;
+ box->sum = sum;
+ box->total_error = -1;
+
+ box->color = averagepixels(colors, &achv[ind]);
+ box->variance = box_variance(achv, box);
+ box->max_error = box_max_error(achv, box);
+}
+
+/*
+ ** Here is the fun part, the median-cut colormap generator. This is based
+ ** on Paul Heckbert's paper, "Color Image Quantization for Frame Buffer
+ ** Display," SIGGRAPH 1982 Proceedings, page 297.
+ */
+LIQ_PRIVATE colormap *mediancut(histogram *hist, unsigned int newcolors, const double target_mse, const double max_mse, void* (*malloc)(size_t), void (*free)(void*))
+{
+ hist_item *achv = hist->achv;
+ LIQ_ARRAY(struct box, bv, newcolors);
+ unsigned int boxes = 1;
+
+ /*
+ ** Set up the initial box.
+ */
+ {
+ double sum = 0;
+ for(unsigned int i=0; i < hist->size; i++) {
+ sum += achv[i].adjusted_weight;
+ }
+ box_init(&bv[0], achv, 0, hist->size, sum);
+
+
+ /*
+ ** Main loop: split boxes until we have enough.
+ */
+ while (boxes < newcolors) {
+
+ // first splits boxes that exceed quality limit (to have colors for things like odd green pixel),
+ // later raises the limit to allow large smooth areas/gradients get colors.
+ const double current_max_mse = max_mse + (boxes/(double)newcolors)*16.0*max_mse;
+ const int bi = best_splittable_box(bv, boxes, current_max_mse);
+ if (bi < 0) {
+ break; /* ran out of colors! */
+ }
+
+ unsigned int indx = bv[bi].ind;
+ unsigned int clrs = bv[bi].colors;
+
+ /*
+ Classic implementation tries to get even number of colors or pixels in each subdivision.
+
+ Here, instead of popularity I use (sqrt(popularity)*variance) metric.
+ Each subdivision balances number of pixels (popular colors) and low variance -
+ boxes can be large if they have similar colors. Later boxes with high variance
+ will be more likely to be split.
+
+ Median used as expected value gives much better results than mean.
+ */
+
+ const double halfvar = prepare_sort(&bv[bi], achv);
+
+ // hist_item_sort_halfvar sorts and sums lowervar at the same time
+ // returns item to break at …minus one, which does smell like an off-by-one error.
+ unsigned int break_at = hist_item_sort_halfvar(&achv[indx], clrs, halfvar);
+ break_at = MIN(clrs-1, break_at + 1);
+
+ /*
+ ** Split the box.
+ */
+ double sm = bv[bi].sum;
+ double lowersum = 0;
+ for(unsigned int i=0; i < break_at; i++) lowersum += achv[indx + i].adjusted_weight;
+
+ box_init(&bv[bi], achv, indx, break_at, lowersum);
+ box_init(&bv[boxes], achv, indx + break_at, clrs - break_at, sm - lowersum);
+
+ ++boxes;
+
+ if (total_box_error_below_target(target_mse, bv, boxes, hist)) {
+ break;
+ }
+ }
+ }
+
+ colormap *map = pam_colormap(boxes, malloc, free);
+ set_colormap_from_boxes(map, bv, boxes, achv);
+
+ adjust_histogram(achv, bv, boxes);
+
+ return map;
+}
+
+static void set_colormap_from_boxes(colormap *map, struct box* bv, unsigned int boxes, hist_item *achv)
+{
+ /*
+ ** Ok, we've got enough boxes. Now choose a representative color for
+ ** each box. There are a number of possible ways to make this choice.
+ ** One would be to choose the center of the box; this ignores any structure
+ ** within the boxes. Another method would be to average all the colors in
+ ** the box - this is the method specified in Heckbert's paper.
+ */
+
+ for(unsigned int bi = 0; bi < boxes; ++bi) {
+ map->palette[bi].acolor = bv[bi].color;
+
+ /* store total color popularity (perceptual_weight is approximation of it) */
+ map->palette[bi].popularity = 0;
+ for(unsigned int i=bv[bi].ind; i < bv[bi].ind+bv[bi].colors; i++) {
+ map->palette[bi].popularity += achv[i].perceptual_weight;
+ }
+ }
+}
+
+/* increase histogram popularity by difference from the final color (this is used as part of feedback loop) */
+static void adjust_histogram(hist_item *achv, const struct box* bv, unsigned int boxes)
+{
+ for(unsigned int bi = 0; bi < boxes; ++bi) {
+ for(unsigned int i=bv[bi].ind; i < bv[bi].ind+bv[bi].colors; i++) {
+ achv[i].tmp.likely_colormap_index = bi;
+ }
+ }
+}
+
+static f_pixel averagepixels(unsigned int clrs, const hist_item achv[])
+{
+ double r = 0, g = 0, b = 0, a = 0, sum = 0;
+
+ #pragma omp parallel for if (clrs > 25000) \
+ schedule(static) default(shared) reduction(+:a) reduction(+:r) reduction(+:g) reduction(+:b) reduction(+:sum)
+ for(unsigned int i = 0; i < clrs; i++) {
+ const f_pixel px = achv[i].acolor;
+ const double weight = achv[i].adjusted_weight;
+
+ sum += weight;
+ a += px.a * weight;
+ r += px.r * weight;
+ g += px.g * weight;
+ b += px.b * weight;
+ }
+
+ if (sum) {
+ a /= sum;
+ r /= sum;
+ g /= sum;
+ b /= sum;
+ }
+
+ assert(!isnan(r) && !isnan(g) && !isnan(b) && !isnan(a));
+
+ return (f_pixel){.r=r, .g=g, .b=b, .a=a};
+}
diff --git a/libs/imagequant/external/libimagequant/mediancut.h b/libs/imagequant/external/libimagequant/mediancut.h
new file mode 100644
index 00000000..9a4cb534
--- /dev/null
+++ b/libs/imagequant/external/libimagequant/mediancut.h
@@ -0,0 +1,6 @@
+#ifndef MEDIANCUT_H
+#define MEDIANCUT_H
+
+LIQ_PRIVATE colormap *mediancut(histogram *hist, unsigned int newcolors, const double target_mse, const double max_mse, void* (*malloc)(size_t), void (*free)(void*));
+
+#endif
diff --git a/libs/imagequant/external/libimagequant/mempool.c b/libs/imagequant/external/libimagequant/mempool.c
new file mode 100644
index 00000000..cd49f59a
--- /dev/null
+++ b/libs/imagequant/external/libimagequant/mempool.c
@@ -0,0 +1,70 @@
+/*
+** © 2009-2017 by Kornel Lesiński.
+** © 1989, 1991 by Jef Poskanzer.
+** © 1997, 2000, 2002 by Greg Roelofs; based on an idea by Stefan Schneider.
+**
+** See COPYRIGHT file for license.
+*/
+
+#include "libimagequant.h"
+#include "mempool.h"
+#include
+#include
+#include
+
+#define ALIGN_MASK 15UL
+#define MEMPOOL_RESERVED ((sizeof(struct mempool)+ALIGN_MASK) & ~ALIGN_MASK)
+
+struct mempool {
+ unsigned int used, size;
+ void* (*malloc)(size_t);
+ void (*free)(void*);
+ struct mempool *next;
+};
+LIQ_PRIVATE void* mempool_create(mempoolptr *mptr, const unsigned int size, unsigned int max_size, void* (*malloc)(size_t), void (*free)(void*))
+{
+ if (*mptr && ((*mptr)->used+size) <= (*mptr)->size) {
+ unsigned int prevused = (*mptr)->used;
+ (*mptr)->used += (size+15UL) & ~0xFUL;
+ return ((char*)(*mptr)) + prevused;
+ }
+
+ mempoolptr old = *mptr;
+ if (!max_size) max_size = (1<<17);
+ max_size = size+ALIGN_MASK > max_size ? size+ALIGN_MASK : max_size;
+
+ *mptr = malloc(MEMPOOL_RESERVED + max_size);
+ if (!*mptr) return NULL;
+ **mptr = (struct mempool){
+ .malloc = malloc,
+ .free = free,
+ .size = MEMPOOL_RESERVED + max_size,
+ .used = sizeof(struct mempool),
+ .next = old,
+ };
+ uintptr_t mptr_used_start = (uintptr_t)(*mptr) + (*mptr)->used;
+ (*mptr)->used += (ALIGN_MASK + 1 - (mptr_used_start & ALIGN_MASK)) & ALIGN_MASK; // reserve bytes required to make subsequent allocations aligned
+ assert(!(((uintptr_t)(*mptr) + (*mptr)->used) & ALIGN_MASK));
+
+ return mempool_alloc(mptr, size, size);
+}
+
+LIQ_PRIVATE void* mempool_alloc(mempoolptr *mptr, const unsigned int size, const unsigned int max_size)
+{
+ if (((*mptr)->used+size) <= (*mptr)->size) {
+ unsigned int prevused = (*mptr)->used;
+ (*mptr)->used += (size + ALIGN_MASK) & ~ALIGN_MASK;
+ return ((char*)(*mptr)) + prevused;
+ }
+
+ return mempool_create(mptr, size, max_size, (*mptr)->malloc, (*mptr)->free);
+}
+
+LIQ_PRIVATE void mempool_destroy(mempoolptr m)
+{
+ while (m) {
+ mempoolptr next = m->next;
+ m->free(m);
+ m = next;
+ }
+}
diff --git a/libs/imagequant/external/libimagequant/mempool.h b/libs/imagequant/external/libimagequant/mempool.h
new file mode 100644
index 00000000..9b7333b1
--- /dev/null
+++ b/libs/imagequant/external/libimagequant/mempool.h
@@ -0,0 +1,13 @@
+#ifndef MEMPOOL_H
+#define MEMPOOL_H
+
+#include
+
+struct mempool;
+typedef struct mempool *mempoolptr;
+
+LIQ_PRIVATE void* mempool_create(mempoolptr *mptr, const unsigned int size, unsigned int capacity, void* (*malloc)(size_t), void (*free)(void*));
+LIQ_PRIVATE void* mempool_alloc(mempoolptr *mptr, const unsigned int size, const unsigned int capacity);
+LIQ_PRIVATE void mempool_destroy(mempoolptr m);
+
+#endif
diff --git a/libs/imagequant/external/libimagequant/nearest.c b/libs/imagequant/external/libimagequant/nearest.c
new file mode 100644
index 00000000..cae477fa
--- /dev/null
+++ b/libs/imagequant/external/libimagequant/nearest.c
@@ -0,0 +1,230 @@
+/*
+** © 2009-2015 by Kornel Lesiński.
+** © 1989, 1991 by Jef Poskanzer.
+** © 1997, 2000, 2002 by Greg Roelofs; based on an idea by Stefan Schneider.
+**
+** See COPYRIGHT file for license.
+*/
+
+#include "libimagequant.h"
+#include "pam.h"
+#include "nearest.h"
+#include "mempool.h"
+#include
+
+typedef struct vp_sort_tmp {
+ float distance_squared;
+ unsigned int idx;
+} vp_sort_tmp;
+
+typedef struct vp_search_tmp {
+ float distance;
+ float distance_squared;
+ unsigned int idx;
+ int exclude;
+} vp_search_tmp;
+
+struct leaf {
+ f_pixel color;
+ unsigned int idx;
+};
+
+typedef struct vp_node {
+ struct vp_node *near, *far;
+ f_pixel vantage_point;
+ float radius, radius_squared;
+ struct leaf *rest;
+ unsigned short idx;
+ unsigned short restcount;
+} vp_node;
+
+struct nearest_map {
+ vp_node *root;
+ const colormap_item *palette;
+ float nearest_other_color_dist[256];
+ mempoolptr mempool;
+};
+
+static void vp_search_node(const vp_node *node, const f_pixel *const needle, vp_search_tmp *const best_candidate);
+
+static int vp_compare_distance(const void *ap, const void *bp) {
+ float a = ((const vp_sort_tmp*)ap)->distance_squared;
+ float b = ((const vp_sort_tmp*)bp)->distance_squared;
+ return a > b ? 1 : -1;
+}
+
+static void vp_sort_indexes_by_distance(const f_pixel vantage_point, vp_sort_tmp indexes[], int num_indexes, const colormap_item items[]) {
+ for(int i=0; i < num_indexes; i++) {
+ indexes[i].distance_squared = colordifference(vantage_point, items[indexes[i].idx].acolor);
+ }
+ qsort(indexes, num_indexes, sizeof(indexes[0]), vp_compare_distance);
+}
+
+/*
+ * Usually it should pick farthest point, but picking most popular point seems to make search quicker anyway
+ */
+static int vp_find_best_vantage_point_index(vp_sort_tmp indexes[], int num_indexes, const colormap_item items[]) {
+ int best = 0;
+ float best_popularity = items[indexes[0].idx].popularity;
+ for(int i = 1; i < num_indexes; i++) {
+ if (items[indexes[i].idx].popularity > best_popularity) {
+ best_popularity = items[indexes[i].idx].popularity;
+ best = i;
+ }
+ }
+ return best;
+}
+
+static vp_node *vp_create_node(mempoolptr *m, vp_sort_tmp indexes[], int num_indexes, const colormap_item items[]) {
+ if (num_indexes <= 0) {
+ return NULL;
+ }
+
+ vp_node *node = mempool_alloc(m, sizeof(node[0]), 0);
+
+ if (num_indexes == 1) {
+ *node = (vp_node){
+ .vantage_point = items[indexes[0].idx].acolor,
+ .idx = indexes[0].idx,
+ .radius = MAX_DIFF,
+ .radius_squared = MAX_DIFF,
+ };
+ return node;
+ }
+
+ const int ref = vp_find_best_vantage_point_index(indexes, num_indexes, items);
+ const int ref_idx = indexes[ref].idx;
+
+ // Removes the `ref_idx` item from remaining items, because it's included in the current node
+ num_indexes -= 1;
+ indexes[ref] = indexes[num_indexes];
+
+ vp_sort_indexes_by_distance(items[ref_idx].acolor, indexes, num_indexes, items);
+
+ // Remaining items are split by the median distance
+ const int half_idx = num_indexes/2;
+
+ *node = (vp_node){
+ .vantage_point = items[ref_idx].acolor,
+ .idx = ref_idx,
+ .radius = sqrtf(indexes[half_idx].distance_squared),
+ .radius_squared = indexes[half_idx].distance_squared,
+ };
+ if (num_indexes < 7) {
+ node->rest = mempool_alloc(m, sizeof(node->rest[0]) * num_indexes, 0);
+ node->restcount = num_indexes;
+ for(int i=0; i < num_indexes; i++) {
+ node->rest[i].idx = indexes[i].idx;
+ node->rest[i].color = items[indexes[i].idx].acolor;
+ }
+ } else {
+ node->near = vp_create_node(m, indexes, half_idx, items);
+ node->far = vp_create_node(m, &indexes[half_idx], num_indexes - half_idx, items);
+ }
+
+ return node;
+}
+
+LIQ_PRIVATE struct nearest_map *nearest_init(const colormap *map) {
+ mempoolptr m = NULL;
+ struct nearest_map *handle = mempool_create(&m, sizeof(handle[0]), sizeof(handle[0]) + sizeof(vp_node)*map->colors+16, map->malloc, map->free);
+
+ LIQ_ARRAY(vp_sort_tmp, indexes, map->colors);
+
+ for(unsigned int i=0; i < map->colors; i++) {
+ indexes[i].idx = i;
+ }
+
+ vp_node *root = vp_create_node(&m, indexes, map->colors, map->palette);
+ *handle = (struct nearest_map){
+ .root = root,
+ .palette = map->palette,
+ .mempool = m,
+ };
+
+ for(unsigned int i=0; i < map->colors; i++) {
+ vp_search_tmp best = {
+ .distance = MAX_DIFF,
+ .distance_squared = MAX_DIFF,
+ .exclude = i,
+ };
+ vp_search_node(root, &map->palette[i].acolor, &best);
+ handle->nearest_other_color_dist[i] = best.distance * best.distance / 4.0; // half of squared distance
+ }
+
+ return handle;
+}
+
+static void vp_search_node(const vp_node *node, const f_pixel *const needle, vp_search_tmp *const best_candidate) {
+ do {
+ const float distance_squared = colordifference(node->vantage_point, *needle);
+ const float distance = sqrtf(distance_squared);
+
+ if (distance_squared < best_candidate->distance_squared && best_candidate->exclude != node->idx) {
+ best_candidate->distance = distance;
+ best_candidate->distance_squared = distance_squared;
+ best_candidate->idx = node->idx;
+ }
+
+ if (node->restcount) {
+ for(int i=0; i < node->restcount; i++) {
+ const float distance_squared = colordifference(node->rest[i].color, *needle);
+ if (distance_squared < best_candidate->distance_squared && best_candidate->exclude != node->rest[i].idx) {
+ best_candidate->distance = sqrtf(distance_squared);
+ best_candidate->distance_squared = distance_squared;
+ best_candidate->idx = node->rest[i].idx;
+ }
+ }
+ return;
+ }
+
+ // Recurse towards most likely candidate first to narrow best candidate's distance as soon as possible
+ if (distance_squared < node->radius_squared) {
+ if (node->near) {
+ vp_search_node(node->near, needle, best_candidate);
+ }
+ // The best node (final answer) may be just ouside the radius, but not farther than
+ // the best distance we know so far. The vp_search_node above should have narrowed
+ // best_candidate->distance, so this path is rarely taken.
+ if (node->far && distance >= node->radius - best_candidate->distance) {
+ node = node->far; // Fast tail recursion
+ } else {
+ return;
+ }
+ } else {
+ if (node->far) {
+ vp_search_node(node->far, needle, best_candidate);
+ }
+ if (node->near && distance <= node->radius + best_candidate->distance) {
+ node = node->near; // Fast tail recursion
+ } else {
+ return;
+ }
+ }
+ } while(true);
+}
+
+LIQ_PRIVATE unsigned int nearest_search(const struct nearest_map *handle, const f_pixel *px, const int likely_colormap_index, float *diff) {
+ const float guess_diff = colordifference(handle->palette[likely_colormap_index].acolor, *px);
+ if (guess_diff < handle->nearest_other_color_dist[likely_colormap_index]) {
+ if (diff) *diff = guess_diff;
+ return likely_colormap_index;
+ }
+
+ vp_search_tmp best_candidate = {
+ .distance = sqrtf(guess_diff),
+ .distance_squared = guess_diff,
+ .idx = likely_colormap_index,
+ .exclude = -1,
+ };
+ vp_search_node(handle->root, px, &best_candidate);
+ if (diff) {
+ *diff = best_candidate.distance * best_candidate.distance;
+ }
+ return best_candidate.idx;
+}
+
+LIQ_PRIVATE void nearest_free(struct nearest_map *centroids)
+{
+ mempool_destroy(centroids->mempool);
+}
diff --git a/libs/imagequant/external/libimagequant/nearest.h b/libs/imagequant/external/libimagequant/nearest.h
new file mode 100644
index 00000000..10a0a2c1
--- /dev/null
+++ b/libs/imagequant/external/libimagequant/nearest.h
@@ -0,0 +1,14 @@
+//
+// nearest.h
+// pngquant
+//
+
+#ifndef NEAREST_H
+#define NEAREST_H
+
+struct nearest_map;
+LIQ_PRIVATE struct nearest_map *nearest_init(const colormap *palette);
+LIQ_PRIVATE unsigned int nearest_search(const struct nearest_map *map, const f_pixel *px, const int palette_index_guess, float *diff);
+LIQ_PRIVATE void nearest_free(struct nearest_map *map);
+
+#endif
diff --git a/libs/imagequant/external/libimagequant/org/pngquant/PngQuant.c b/libs/imagequant/external/libimagequant/org/pngquant/PngQuant.c
new file mode 100644
index 00000000..06fa5472
--- /dev/null
+++ b/libs/imagequant/external/libimagequant/org/pngquant/PngQuant.c
@@ -0,0 +1,156 @@
+#include "org/pngquant/PngQuant.h"
+#include "org/pngquant/Image.h"
+#include "org/pngquant/Result.h"
+#include "libimagequant.h"
+#include
+
+typedef struct {
+ liq_image *image;
+ jbyte *data;
+} liq_jni_image;
+
+static void *handle(JNIEnv *env, jobject obj) {
+ jlong h = (*env)->GetLongField(env, obj, (*env)->GetFieldID(env, (*env)->GetObjectClass(env, obj), "handle", "J"));
+ return (void*)h;
+}
+
+JNIEXPORT jlong JNICALL Java_org_pngquant_PngQuant_liq_1attr_1create(JNIEnv *env, jclass class) {
+ return (jlong)liq_attr_create();
+}
+
+JNIEXPORT jlong JNICALL Java_org_pngquant_PngQuant_liq_1attr_1copy(JNIEnv *env, jclass class, jlong attr) {
+ return (jlong)liq_attr_copy((liq_attr*)attr);
+}
+
+JNIEXPORT void JNICALL Java_org_pngquant_PngQuant_liq_1attr_1destroy(JNIEnv *env, jclass class, jlong attr) {
+ return liq_attr_destroy((liq_attr*)attr);
+}
+
+JNIEXPORT jboolean JNICALL Java_org_pngquant_PngQuant_setMaxColors(JNIEnv *env, jobject obj, jint colors) {
+ return LIQ_OK == liq_set_max_colors(handle(env, obj), colors);
+}
+
+JNIEXPORT jboolean JNICALL Java_org_pngquant_PngQuant_setSpeed(JNIEnv *env, jobject obj, jint speed) {
+ return LIQ_OK == liq_set_speed(handle(env, obj), speed);
+}
+
+JNIEXPORT jboolean JNICALL Java_org_pngquant_PngQuant_setMinPosterization(JNIEnv *env, jobject obj, jint p) {
+ return LIQ_OK == liq_set_min_posterization(handle(env, obj), p);
+}
+
+JNIEXPORT jboolean JNICALL Java_org_pngquant_PngQuant_setQuality__I(JNIEnv *env, jobject obj, jint q) {
+ return LIQ_OK == liq_set_quality(handle(env, obj), q/2, q);
+}
+
+JNIEXPORT jboolean JNICALL Java_org_pngquant_PngQuant_setQuality__II(JNIEnv *env, jobject obj, jint qmin, jint qmax) {
+ return LIQ_OK == liq_set_quality(handle(env, obj), qmin, qmax);
+}
+
+static void convert_abgr(liq_color row_out[], int row_index, int width, void* user_info) {
+ liq_jni_image *jniimg = user_info;
+ int column_index;
+ for(column_index=0; column_index < width; column_index++) {
+ row_out[column_index].r = jniimg->data[4*(width*row_index + column_index) + 3];
+ row_out[column_index].g = jniimg->data[4*(width*row_index + column_index) + 2];
+ row_out[column_index].b = jniimg->data[4*(width*row_index + column_index) + 1];
+ row_out[column_index].a = jniimg->data[4*(width*row_index + column_index) + 0];
+ }
+}
+
+static void convert_bgr(liq_color row_out[], int row_index, int width, void* user_info) {
+ liq_jni_image *jniimg = user_info;
+ int column_index;
+ for(column_index=0; column_index < width; column_index++) {
+ row_out[column_index].r = jniimg->data[3*(width*row_index + column_index) + 2];
+ row_out[column_index].g = jniimg->data[3*(width*row_index + column_index) + 1];
+ row_out[column_index].b = jniimg->data[3*(width*row_index + column_index) + 0];
+ row_out[column_index].a = 255;
+ }
+}
+
+JNIEXPORT jlong JNICALL Java_org_pngquant_Image_liq_1image_1create(JNIEnv *env, jclass class, jlong attr, jbyteArray bytearray, jint w, jint h, jint components) {
+ /* liq_image needs to be wrapped to keep track of allocated buffer */
+ liq_jni_image *jniimg = malloc(sizeof(liq_jni_image));
+
+ /* copying buffer, since ReleaseByteArrayElements was crashing when called from finalize() */
+ jsize size = (*env)->GetArrayLength(env, bytearray);
+ jniimg->data = malloc(size);
+ (*env)->GetByteArrayRegion(env, bytearray, 0, size, jniimg->data);
+
+ jniimg->image = liq_image_create_custom((liq_attr*)attr, components == 4 ? convert_abgr : convert_bgr, jniimg, w, h, 0);
+
+ if (!jniimg->image) {
+ free(jniimg->data);
+ free(jniimg);
+ return 0;
+ }
+ return (jlong)jniimg;
+}
+
+JNIEXPORT jboolean JNICALL Java_org_pngquant_Image_addFixedColor(JNIEnv *env, jobject obj, jint r, jint g, jint b, jint a) {
+ liq_color c = {r,g,b,a};
+ return LIQ_OK == liq_image_add_fixed_color(((liq_jni_image*)handle(env,obj))->image, c);
+}
+
+JNIEXPORT jint JNICALL Java_org_pngquant_Image_getWidth(JNIEnv *env, jobject obj) {
+ return liq_image_get_width(((liq_jni_image*)handle(env,obj))->image);
+}
+
+JNIEXPORT jint JNICALL Java_org_pngquant_Image_getHeight(JNIEnv *env, jobject obj) {
+ return liq_image_get_height(((liq_jni_image*)handle(env,obj))->image);
+}
+
+JNIEXPORT void JNICALL Java_org_pngquant_Image_liq_1image_1destroy(JNIEnv *env, jclass class, jlong handle) {
+ liq_jni_image *jniimg = (liq_jni_image*)handle;
+ liq_image_destroy(jniimg->image);
+ free(jniimg->data);
+ free(jniimg);
+}
+
+JNIEXPORT jlong JNICALL Java_org_pngquant_Result_liq_1quantize_1image(JNIEnv *env, jclass class, jlong attr, jlong handle) {
+ return (jlong)liq_quantize_image((liq_attr*)attr, ((liq_jni_image*)handle)->image);
+}
+
+JNIEXPORT jboolean JNICALL Java_org_pngquant_Result_setDitheringLevel(JNIEnv *env, jobject obj, jfloat l) {
+ return LIQ_OK == liq_set_dithering_level(handle(env, obj), l);
+}
+
+JNIEXPORT jboolean JNICALL Java_org_pngquant_Result_setGamma(JNIEnv *env, jobject obj, jdouble gamma) {
+ return LIQ_OK == liq_set_output_gamma(handle(env, obj), gamma);
+}
+
+JNIEXPORT jdouble JNICALL Java_org_pngquant_Result_getGamma(JNIEnv *env, jobject obj) {
+ return liq_get_output_gamma(handle(env, obj));
+}
+
+JNIEXPORT jboolean JNICALL Java_org_pngquant_Result_liq_1write_1remapped_1image(JNIEnv *env, jclass class, jlong result, jlong image_handle, jbyteArray bytearray) {
+ jsize size = (*env)->GetArrayLength(env, bytearray);
+
+ jbyte *bitmap = (*env)->GetByteArrayElements(env, bytearray, 0);
+ liq_error err = liq_write_remapped_image((liq_result*)result, ((liq_jni_image*)image_handle)->image, bitmap, size);
+ (*env)->ReleaseByteArrayElements(env, bytearray, bitmap, 0);
+
+ return LIQ_OK == err;
+}
+
+JNIEXPORT jdouble JNICALL Java_org_pngquant_Result_getMeanSquareError(JNIEnv *env, jobject obj) {
+ return liq_get_quantization_error(handle(env, obj));
+}
+
+JNIEXPORT jint JNICALL Java_org_pngquant_Result_getQuality(JNIEnv *env, jobject obj) {
+ return liq_get_quantization_quality(handle(env, obj));
+}
+
+JNIEXPORT void JNICALL Java_org_pngquant_Result_liq_1result_1destroy(JNIEnv *env, jclass class, jlong result) {
+ return liq_result_destroy((liq_result*)result);
+}
+
+JNIEXPORT jbyteArray JNICALL Java_org_pngquant_Result_liq_1get_1palette(JNIEnv *env, jclass class, jlong result) {
+ const liq_palette *pal = liq_get_palette((liq_result*)result);
+ jbyteArray arr = (*env)->NewByteArray(env, pal->count * 4);
+ int i;
+ for(i=0; i < pal->count; i++) {
+ (*env)->SetByteArrayRegion(env, arr, i*4, 4, ((jbyte*)&pal->entries[i]));
+ }
+ return arr;
+}
diff --git a/libs/imagequant/external/libimagequant/pam.c b/libs/imagequant/external/libimagequant/pam.c
new file mode 100644
index 00000000..139c78e9
--- /dev/null
+++ b/libs/imagequant/external/libimagequant/pam.c
@@ -0,0 +1,288 @@
+/* pam.c - pam (portable alpha map) utility library
+**
+** © 2009-2017 by Kornel Lesiński.
+** © 1989, 1991 by Jef Poskanzer.
+** © 1997, 2000, 2002 by Greg Roelofs; based on an idea by Stefan Schneider.
+**
+** See COPYRIGHT file for license.
+*/
+
+#include
+#include
+
+#include "libimagequant.h"
+#include "pam.h"
+#include "mempool.h"
+
+LIQ_PRIVATE bool pam_computeacolorhash(struct acolorhash_table *acht, const rgba_pixel *const pixels[], unsigned int cols, unsigned int rows, const unsigned char *importance_map)
+{
+ const unsigned int ignorebits = acht->ignorebits;
+ const unsigned int channel_mask = 255U>>ignorebits<>ignorebits) ^ 0xFFU;
+ const unsigned int posterize_mask = channel_mask << 24 | channel_mask << 16 | channel_mask << 8 | channel_mask;
+ const unsigned int posterize_high_mask = channel_hmask << 24 | channel_hmask << 16 | channel_hmask << 8 | channel_hmask;
+
+ const unsigned int hash_size = acht->hash_size;
+
+ /* Go through the entire image, building a hash table of colors. */
+ for(unsigned int row = 0; row < rows; ++row) {
+
+ for(unsigned int col = 0; col < cols; ++col) {
+ unsigned int boost;
+
+ // RGBA color is casted to long for easier hasing/comparisons
+ union rgba_as_int px = {pixels[row][col]};
+ unsigned int hash;
+ if (px.rgba.a) {
+ // mask posterizes all 4 channels in one go
+ px.l = (px.l & posterize_mask) | ((px.l & posterize_high_mask) >> (8-ignorebits));
+ // fancier hashing algorithms didn't improve much
+ hash = px.l % hash_size;
+
+ if (importance_map) {
+ boost = *importance_map++;
+ } else {
+ boost = 255;
+ }
+ } else {
+ // "dirty alpha" has different RGBA values that end up being the same fully transparent color
+ px.l=0; hash=0;
+
+ boost = 2000;
+ if (importance_map) {
+ importance_map++;
+ }
+ }
+
+ if (!pam_add_to_hash(acht, hash, boost, px, row, rows)) {
+ return false;
+ }
+ }
+ }
+ acht->cols = cols;
+ acht->rows += rows;
+ return true;
+}
+
+LIQ_PRIVATE bool pam_add_to_hash(struct acolorhash_table *acht, unsigned int hash, unsigned int boost, union rgba_as_int px, unsigned int row, unsigned int rows)
+{
+ /* head of the hash function stores first 2 colors inline (achl->used = 1..2),
+ to reduce number of allocations of achl->other_items.
+ */
+ struct acolorhist_arr_head *achl = &acht->buckets[hash];
+ if (achl->inline1.color.l == px.l && achl->used) {
+ achl->inline1.perceptual_weight += boost;
+ return true;
+ }
+ if (achl->used) {
+ if (achl->used > 1) {
+ if (achl->inline2.color.l == px.l) {
+ achl->inline2.perceptual_weight += boost;
+ return true;
+ }
+ // other items are stored as an array (which gets reallocated if needed)
+ struct acolorhist_arr_item *other_items = achl->other_items;
+ unsigned int i = 0;
+ for (; i < achl->used-2; i++) {
+ if (other_items[i].color.l == px.l) {
+ other_items[i].perceptual_weight += boost;
+ return true;
+ }
+ }
+
+ // the array was allocated with spare items
+ if (i < achl->capacity) {
+ other_items[i] = (struct acolorhist_arr_item){
+ .color = px,
+ .perceptual_weight = boost,
+ };
+ achl->used++;
+ ++acht->colors;
+ return true;
+ }
+
+ if (++acht->colors > acht->maxcolors) {
+ return false;
+ }
+
+ struct acolorhist_arr_item *new_items;
+ unsigned int capacity;
+ if (!other_items) { // there was no array previously, alloc "small" array
+ capacity = 8;
+ if (acht->freestackp <= 0) {
+ // estimate how many colors are going to be + headroom
+ const size_t mempool_size = ((acht->rows + rows-row) * 2 * acht->colors / (acht->rows + row + 1) + 1024) * sizeof(struct acolorhist_arr_item);
+ new_items = mempool_alloc(&acht->mempool, sizeof(struct acolorhist_arr_item)*capacity, mempool_size);
+ } else {
+ // freestack stores previously freed (reallocated) arrays that can be reused
+ // (all pesimistically assumed to be capacity = 8)
+ new_items = acht->freestack[--acht->freestackp];
+ }
+ } else {
+ const unsigned int stacksize = sizeof(acht->freestack)/sizeof(acht->freestack[0]);
+
+ // simply reallocs and copies array to larger capacity
+ capacity = achl->capacity*2 + 16;
+ if (acht->freestackp < stacksize-1) {
+ acht->freestack[acht->freestackp++] = other_items;
+ }
+ const size_t mempool_size = ((acht->rows + rows-row) * 2 * acht->colors / (acht->rows + row + 1) + 32*capacity) * sizeof(struct acolorhist_arr_item);
+ new_items = mempool_alloc(&acht->mempool, sizeof(struct acolorhist_arr_item)*capacity, mempool_size);
+ if (!new_items) return false;
+ memcpy(new_items, other_items, sizeof(other_items[0])*achl->capacity);
+ }
+
+ achl->other_items = new_items;
+ achl->capacity = capacity;
+ new_items[i] = (struct acolorhist_arr_item){
+ .color = px,
+ .perceptual_weight = boost,
+ };
+ achl->used++;
+ } else {
+ // these are elses for first checks whether first and second inline-stored colors are used
+ achl->inline2.color.l = px.l;
+ achl->inline2.perceptual_weight = boost;
+ achl->used = 2;
+ ++acht->colors;
+ }
+ } else {
+ achl->inline1.color.l = px.l;
+ achl->inline1.perceptual_weight = boost;
+ achl->used = 1;
+ ++acht->colors;
+ }
+ return true;
+}
+
+LIQ_PRIVATE struct acolorhash_table *pam_allocacolorhash(unsigned int maxcolors, unsigned int surface, unsigned int ignorebits, void* (*malloc)(size_t), void (*free)(void*))
+{
+ const size_t estimated_colors = MIN(maxcolors, surface/(ignorebits + (surface > 512*512 ? 6 : 5)));
+ const size_t hash_size = estimated_colors < 66000 ? 6673 : (estimated_colors < 200000 ? 12011 : 24019);
+
+ mempoolptr m = NULL;
+ const size_t buckets_size = hash_size * sizeof(struct acolorhist_arr_head);
+ const size_t mempool_size = sizeof(struct acolorhash_table) + buckets_size + estimated_colors * sizeof(struct acolorhist_arr_item);
+ struct acolorhash_table *t = mempool_create(&m, sizeof(*t) + buckets_size, mempool_size, malloc, free);
+ if (!t) return NULL;
+ *t = (struct acolorhash_table){
+ .mempool = m,
+ .hash_size = hash_size,
+ .maxcolors = maxcolors,
+ .ignorebits = ignorebits,
+ };
+ memset(t->buckets, 0, buckets_size);
+ return t;
+}
+
+ALWAYS_INLINE static float pam_add_to_hist(const float *gamma_lut, hist_item *achv, unsigned int *j, const struct acolorhist_arr_item *entry, const float max_perceptual_weight)
+{
+ if (entry->perceptual_weight == 0 && *j > 0) {
+ return 0;
+ }
+ const float w = MIN(entry->perceptual_weight/128.f, max_perceptual_weight);
+ achv[*j].adjusted_weight = achv[*j].perceptual_weight = w;
+ achv[*j].acolor = rgba_to_f(gamma_lut, entry->color.rgba);
+ *j += 1;
+ return w;
+}
+
+LIQ_PRIVATE histogram *pam_acolorhashtoacolorhist(const struct acolorhash_table *acht, const double gamma, void* (*malloc)(size_t), void (*free)(void*))
+{
+ histogram *hist = malloc(sizeof(hist[0]));
+ if (!hist || !acht) return NULL;
+ *hist = (histogram){
+ .achv = malloc(MAX(1,acht->colors) * sizeof(hist->achv[0])),
+ .size = acht->colors,
+ .free = free,
+ .ignorebits = acht->ignorebits,
+ };
+ if (!hist->achv) return NULL;
+
+ float gamma_lut[256];
+ to_f_set_gamma(gamma_lut, gamma);
+
+ /* Limit perceptual weight to 1/10th of the image surface area to prevent
+ a single color from dominating all others. */
+ float max_perceptual_weight = 0.1f * acht->cols * acht->rows;
+ double total_weight = 0;
+
+ unsigned int j=0;
+ for(unsigned int i=0; i < acht->hash_size; ++i) {
+ const struct acolorhist_arr_head *const achl = &acht->buckets[i];
+ if (achl->used) {
+ total_weight += pam_add_to_hist(gamma_lut, hist->achv, &j, &achl->inline1, max_perceptual_weight);
+
+ if (achl->used > 1) {
+ total_weight += pam_add_to_hist(gamma_lut, hist->achv, &j, &achl->inline2, max_perceptual_weight);
+
+ for(unsigned int k=0; k < achl->used-2; k++) {
+ total_weight += pam_add_to_hist(gamma_lut, hist->achv, &j, &achl->other_items[k], max_perceptual_weight);
+ }
+ }
+ }
+ }
+ hist->size = j;
+ hist->total_perceptual_weight = total_weight;
+ for(unsigned int k=0; k < hist->size; k++) {
+ hist->achv[k].tmp.likely_colormap_index = 0;
+ }
+ if (!j) {
+ pam_freeacolorhist(hist);
+ return NULL;
+ }
+ return hist;
+}
+
+
+LIQ_PRIVATE void pam_freeacolorhash(struct acolorhash_table *acht)
+{
+ if (acht) {
+ mempool_destroy(acht->mempool);
+ }
+}
+
+LIQ_PRIVATE void pam_freeacolorhist(histogram *hist)
+{
+ hist->free(hist->achv);
+ hist->free(hist);
+}
+
+LIQ_PRIVATE colormap *pam_colormap(unsigned int colors, void* (*malloc)(size_t), void (*free)(void*))
+{
+ assert(colors > 0 && colors < 65536);
+
+ colormap *map;
+ const size_t colors_size = colors * sizeof(map->palette[0]);
+ map = malloc(sizeof(colormap) + colors_size);
+ if (!map) return NULL;
+ *map = (colormap){
+ .malloc = malloc,
+ .free = free,
+ .colors = colors,
+ };
+ memset(map->palette, 0, colors_size);
+ return map;
+}
+
+LIQ_PRIVATE colormap *pam_duplicate_colormap(colormap *map)
+{
+ colormap *dupe = pam_colormap(map->colors, map->malloc, map->free);
+ for(unsigned int i=0; i < map->colors; i++) {
+ dupe->palette[i] = map->palette[i];
+ }
+ return dupe;
+}
+
+LIQ_PRIVATE void pam_freecolormap(colormap *c)
+{
+ c->free(c);
+}
+
+LIQ_PRIVATE void to_f_set_gamma(float gamma_lut[], const double gamma)
+{
+ for(int i=0; i < 256; i++) {
+ gamma_lut[i] = pow((double)i/255.0, internal_gamma/gamma);
+ }
+}
+
diff --git a/libs/imagequant/external/libimagequant/pam.h b/libs/imagequant/external/libimagequant/pam.h
new file mode 100644
index 00000000..0c72392a
--- /dev/null
+++ b/libs/imagequant/external/libimagequant/pam.h
@@ -0,0 +1,292 @@
+/* pam.h - pam (portable alpha map) utility library
+ **
+ ** Colormap routines.
+ **
+ ** Copyright (C) 1989, 1991 by Jef Poskanzer.
+ ** Copyright (C) 1997 by Greg Roelofs.
+ **
+ ** Permission to use, copy, modify, and distribute this software and its
+ ** documentation for any purpose and without fee is hereby granted, provided
+ ** that the above copyright notice appear in all copies and that both that
+ ** copyright notice and this permission notice appear in supporting
+ ** documentation. This software is provided "as is" without express or
+ ** implied warranty.
+ */
+
+#ifndef PAM_H
+#define PAM_H
+
+// accidental debug assertions make color search much slower,
+// so force assertions off if there's no explicit setting
+#if !defined(NDEBUG) && !defined(DEBUG)
+#define NDEBUG
+#endif
+
+#include
+#include
+#include
+#include
+
+#ifndef MAX
+# define MAX(a,b) ((a) > (b)? (a) : (b))
+# define MIN(a,b) ((a) < (b)? (a) : (b))
+#endif
+
+#define MAX_DIFF 1e20
+
+#ifndef USE_SSE
+# if defined(__SSE__) && (defined(__amd64__) || defined(__X86_64__) || defined(_WIN64) || defined(WIN32) || defined(__WIN32__))
+# define USE_SSE 1
+# else
+# define USE_SSE 0
+# endif
+#endif
+
+#if USE_SSE
+# include
+# ifdef _MSC_VER
+# include
+# define SSE_ALIGN
+# else
+# define SSE_ALIGN __attribute__ ((aligned (16)))
+# if defined(__i386__) && defined(__PIC__)
+# define cpuid(func,ax,bx,cx,dx)\
+ __asm__ __volatile__ ( \
+ "push %%ebx\n" \
+ "cpuid\n" \
+ "mov %%ebx, %1\n" \
+ "pop %%ebx\n" \
+ : "=a" (ax), "=r" (bx), "=c" (cx), "=d" (dx) \
+ : "a" (func));
+# else
+# define cpuid(func,ax,bx,cx,dx)\
+ __asm__ __volatile__ ("cpuid":\
+ "=a" (ax), "=b" (bx), "=c" (cx), "=d" (dx) : "a" (func));
+# endif
+#endif
+#else
+# define SSE_ALIGN
+#endif
+
+#ifndef _MSC_VER
+#define LIQ_ARRAY(type, var, count) type var[count]
+#else
+#define LIQ_ARRAY(type, var, count) type* var = (type*)_alloca(sizeof(type)*(count))
+#endif
+
+#if defined(__GNUC__) || defined (__llvm__)
+#define ALWAYS_INLINE __attribute__((always_inline)) inline
+#define NEVER_INLINE __attribute__ ((noinline))
+#elif defined(_MSC_VER)
+#define inline __inline
+#define restrict __restrict
+#define ALWAYS_INLINE __forceinline
+#define NEVER_INLINE __declspec(noinline)
+#else
+#define ALWAYS_INLINE inline
+#define NEVER_INLINE
+#endif
+
+/* from pam.h */
+
+typedef struct {
+ unsigned char r, g, b, a;
+} rgba_pixel;
+
+typedef struct {
+ float a, r, g, b;
+} SSE_ALIGN f_pixel;
+
+static const float internal_gamma = 0.5499f;
+
+LIQ_PRIVATE void to_f_set_gamma(float gamma_lut[], const double gamma);
+
+/**
+ Converts 8-bit color to internal gamma and premultiplied alpha.
+ (premultiplied color space is much better for blending of semitransparent colors)
+ */
+ALWAYS_INLINE static f_pixel rgba_to_f(const float gamma_lut[], const rgba_pixel px);
+inline static f_pixel rgba_to_f(const float gamma_lut[], const rgba_pixel px)
+{
+ float a = px.a/255.f;
+
+ return (f_pixel) {
+ .a = a,
+ .r = gamma_lut[px.r]*a,
+ .g = gamma_lut[px.g]*a,
+ .b = gamma_lut[px.b]*a,
+ };
+}
+
+inline static rgba_pixel f_to_rgb(const float gamma, const f_pixel px)
+{
+ if (px.a < 1.f/256.f) {
+ return (rgba_pixel){0,0,0,0};
+ }
+
+ float r = px.r / px.a,
+ g = px.g / px.a,
+ b = px.b / px.a,
+ a = px.a;
+
+ r = powf(r, gamma/internal_gamma);
+ g = powf(g, gamma/internal_gamma);
+ b = powf(b, gamma/internal_gamma);
+
+ // 256, because numbers are in range 1..255.9999… rounded down
+ r *= 256.f;
+ g *= 256.f;
+ b *= 256.f;
+ a *= 256.f;
+
+ return (rgba_pixel){
+ .r = r>=255.f ? 255 : r,
+ .g = g>=255.f ? 255 : g,
+ .b = b>=255.f ? 255 : b,
+ .a = a>=255.f ? 255 : a,
+ };
+}
+
+ALWAYS_INLINE static float colordifference_ch(const float x, const float y, const float alphas);
+inline static float colordifference_ch(const float x, const float y, const float alphas)
+{
+ // maximum of channel blended on white, and blended on black
+ // premultiplied alpha and backgrounds 0/1 shorten the formula
+ const float black = x-y, white = black+alphas;
+ return MAX(black*black, white*white);
+}
+
+ALWAYS_INLINE static float colordifference_stdc(const f_pixel px, const f_pixel py);
+inline static float colordifference_stdc(const f_pixel px, const f_pixel py)
+{
+ // px_b.rgb = px.rgb + 0*(1-px.a) // blend px on black
+ // px_b.a = px.a + 1*(1-px.a)
+ // px_w.rgb = px.rgb + 1*(1-px.a) // blend px on white
+ // px_w.a = px.a + 1*(1-px.a)
+
+ // px_b.rgb = px.rgb // difference same as in opaque RGB
+ // px_b.a = 1
+ // px_w.rgb = px.rgb - px.a // difference simplifies to formula below
+ // px_w.a = 1
+
+ // (px.rgb - px.a) - (py.rgb - py.a)
+ // (px.rgb - py.rgb) + (py.a - px.a)
+
+ const float alphas = py.a-px.a;
+ return colordifference_ch(px.r, py.r, alphas) +
+ colordifference_ch(px.g, py.g, alphas) +
+ colordifference_ch(px.b, py.b, alphas);
+}
+
+ALWAYS_INLINE static float colordifference(f_pixel px, f_pixel py);
+inline static float colordifference(f_pixel px, f_pixel py)
+{
+#if USE_SSE
+#ifdef _MSC_VER
+ /* In MSVC we cannot use the align attribute in parameters.
+ * This is used a lot, so we just use an unaligned load.
+ * Also the compiler incorrectly inlines vpx and vpy without
+ * the volatile when optimization is applied for x86_64. */
+ const volatile __m128 vpx = _mm_loadu_ps((const float*)&px);
+ const volatile __m128 vpy = _mm_loadu_ps((const float*)&py);
+#else
+ const __m128 vpx = _mm_load_ps((const float*)&px);
+ const __m128 vpy = _mm_load_ps((const float*)&py);
+#endif
+
+ // y.a - x.a
+ __m128 alphas = _mm_sub_ss(vpy, vpx);
+ alphas = _mm_shuffle_ps(alphas,alphas,0); // copy first to all four
+
+ __m128 onblack = _mm_sub_ps(vpx, vpy); // x - y
+ __m128 onwhite = _mm_add_ps(onblack, alphas); // x - y + (y.a - x.a)
+
+ onblack = _mm_mul_ps(onblack, onblack);
+ onwhite = _mm_mul_ps(onwhite, onwhite);
+ const __m128 max = _mm_max_ps(onwhite, onblack);
+
+ // add rgb, not a
+ const __m128 maxhl = _mm_movehl_ps(max, max);
+ const __m128 tmp = _mm_add_ps(max, maxhl);
+ const __m128 sum = _mm_add_ss(maxhl, _mm_shuffle_ps(tmp, tmp, 1));
+
+ const float res = _mm_cvtss_f32(sum);
+ assert(fabs(res - colordifference_stdc(px,py)) < 0.001);
+ return res;
+#else
+ return colordifference_stdc(px,py);
+#endif
+}
+
+/* from pamcmap.h */
+union rgba_as_int {
+ rgba_pixel rgba;
+ unsigned int l;
+};
+
+typedef struct {
+ f_pixel acolor;
+ float adjusted_weight, // perceptual weight changed to tweak how mediancut selects colors
+ perceptual_weight; // number of pixels weighted by importance of different areas of the picture
+
+ float color_weight; // these two change every time histogram subset is sorted
+ union {
+ unsigned int sort_value;
+ unsigned char likely_colormap_index;
+ } tmp;
+} hist_item;
+
+typedef struct {
+ hist_item *achv;
+ void (*free)(void*);
+ double total_perceptual_weight;
+ unsigned int size;
+ unsigned int ignorebits;
+} histogram;
+
+typedef struct {
+ f_pixel acolor;
+ float popularity;
+ bool fixed; // if true it's user-supplied and must not be changed (e.g in K-Means iteration)
+} colormap_item;
+
+typedef struct colormap {
+ unsigned int colors;
+ void* (*malloc)(size_t);
+ void (*free)(void*);
+ colormap_item palette[];
+} colormap;
+
+struct acolorhist_arr_item {
+ union rgba_as_int color;
+ unsigned int perceptual_weight;
+};
+
+struct acolorhist_arr_head {
+ struct acolorhist_arr_item inline1, inline2;
+ unsigned int used, capacity;
+ struct acolorhist_arr_item *other_items;
+};
+
+struct acolorhash_table {
+ struct mempool *mempool;
+ unsigned int ignorebits, maxcolors, colors, cols, rows;
+ unsigned int hash_size;
+ unsigned int freestackp;
+ struct acolorhist_arr_item *freestack[512];
+ struct acolorhist_arr_head buckets[];
+};
+
+LIQ_PRIVATE void pam_freeacolorhash(struct acolorhash_table *acht);
+LIQ_PRIVATE struct acolorhash_table *pam_allocacolorhash(unsigned int maxcolors, unsigned int surface, unsigned int ignorebits, void* (*malloc)(size_t), void (*free)(void*));
+LIQ_PRIVATE histogram *pam_acolorhashtoacolorhist(const struct acolorhash_table *acht, const double gamma, void* (*malloc)(size_t), void (*free)(void*));
+LIQ_PRIVATE bool pam_computeacolorhash(struct acolorhash_table *acht, const rgba_pixel *const pixels[], unsigned int cols, unsigned int rows, const unsigned char *importance_map);
+LIQ_PRIVATE bool pam_add_to_hash(struct acolorhash_table *acht, unsigned int hash, unsigned int boost, union rgba_as_int px, unsigned int row, unsigned int rows);
+
+LIQ_PRIVATE void pam_freeacolorhist(histogram *h);
+
+LIQ_PRIVATE colormap *pam_colormap(unsigned int colors, void* (*malloc)(size_t), void (*free)(void*));
+LIQ_PRIVATE colormap *pam_duplicate_colormap(colormap *map);
+LIQ_PRIVATE void pam_freecolormap(colormap *c);
+
+#endif
diff --git a/libs/imagequant/external/libimagequant/version.txt b/libs/imagequant/external/libimagequant/version.txt
new file mode 100644
index 00000000..d76bd2ba
--- /dev/null
+++ b/libs/imagequant/external/libimagequant/version.txt
@@ -0,0 +1 @@
+2.17.0
diff --git a/libs/imagequant/external/libpng/CMakeLists.txt b/libs/imagequant/external/libpng/CMakeLists.txt
new file mode 100644
index 00000000..127c7e49
--- /dev/null
+++ b/libs/imagequant/external/libpng/CMakeLists.txt
@@ -0,0 +1,998 @@
+# CMakeLists.txt - CMake lists for libpng
+#
+# Copyright (c) 2018-2025 Cosmin Truta
+# Copyright (c) 2007-2018 Glenn Randers-Pehrson
+# Originally written by Christian Ehrlicher, 2007
+#
+# Use, modification and distribution are subject to
+# the same licensing terms and conditions as libpng.
+# Please see the copyright notice in png.h or visit
+# http://libpng.org/pub/png/src/libpng-LICENSE.txt
+#
+# For copyright and licensing purposes, please see
+# the accompanying file scripts/cmake/AUTHORS.md
+#
+# SPDX-License-Identifier: libpng-2.0
+
+cmake_minimum_required(VERSION 3.14...4.0)
+
+set(PNGLIB_MAJOR 1)
+set(PNGLIB_MINOR 6)
+set(PNGLIB_REVISION 49)
+#set(PNGLIB_SUBREVISION 0)
+set(PNGLIB_SUBREVISION "git")
+set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_REVISION})
+set(PNGLIB_ABI_VERSION ${PNGLIB_MAJOR}${PNGLIB_MINOR})
+set(PNGLIB_SHARED_VERSION ${PNGLIB_ABI_VERSION}.${PNGLIB_REVISION}.${PNGLIB_SUBREVISION})
+
+project(libpng
+ VERSION ${PNGLIB_VERSION}
+ LANGUAGES C ASM)
+
+include(CheckCSourceCompiles)
+include(GNUInstallDirs)
+
+# Allow the users to specify an application-specific API prefix for libpng
+# vendoring purposes. A standard libpng build should have no such prefix.
+set(PNG_PREFIX
+ ""
+ CACHE STRING "Prefix to prepend to the API function names")
+
+# Allow the users to override the postfix appended to debug library file names.
+# Previously, we used to set CMAKE_DEBUG_POSTFIX globally. That variable should
+# not be cached, however, because doing so would affect all projects processed
+# after libpng, in unexpected and undesirable ways.
+set(PNG_DEBUG_POSTFIX
+ "d"
+ CACHE STRING "Postfix to append to library file names under the Debug configuration")
+
+# Allow the users to import their own extra configuration settings.
+# Those settings can be either passed via DFA_XTRA if they are in DFA form
+# (such as "pngusr.dfa"), or via PNG_LIBCONF_HEADER if they are in prebuilt
+# header file form (such as "scripts/pnglibconf.h.prebuilt"), but not both.
+# For platforms such as Android or iOS, or in certain cross-platform build
+# scenarios, having a valid PNG_LIBCONF_HEADER is mandatory.
+set(DFA_XTRA
+ ""
+ CACHE FILEPATH "DFA file containing customized build configuration settings for libpng")
+set(PNG_LIBCONF_HEADER
+ ""
+ CACHE FILEPATH "C header file containing customized build configuration settings for libpng")
+
+# set(PNG_LIBCONF_HEADER_PREBUILT "${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.h.prebuilt")
+# if(ANDROID OR IOS)
+# set(PNG_LIBCONF_HEADER "${PNG_LIBCONF_HEADER_PREBUILT}")
+# endif()
+set(PNG_LIBCONF_HEADER "${CMAKE_CURRENT_SOURCE_DIR}/pnglibconf.h")
+
+if((NOT DFA_XTRA STREQUAL "") AND (NOT PNG_LIBCONF_HEADER STREQUAL ""))
+ message(SEND_ERROR "The options DFA_XTRA=\"${DFA_XTRA}\" "
+ "and PNG_LIBCONF_HEADER=\"${PNG_LIBCONF_HEADER}\" "
+ "are mutually exclusive")
+endif()
+
+# Allow the users to switch on/off various library build types.
+option(PNG_SHARED "Build libpng as a shared library" ON)
+option(PNG_STATIC "Build libpng as a static library" ON)
+if(APPLE)
+ option(PNG_FRAMEWORK "Build libpng as a framework bundle" ON)
+else()
+ option(PNG_FRAMEWORK "Build libpng as a framework bundle (not available on this platform)" OFF)
+endif()
+if(NOT APPLE AND PNG_FRAMEWORK)
+ message(SEND_ERROR "The option PNG_FRAMEWORK should not be set on this platform")
+endif()
+
+# Allow the users to switch on/off the auxiliary build and test artifacts.
+# These artifacts are NOT part of libpng proper, and are subject to change
+# at any time.
+option(PNG_TESTS "Build the libpng tests" ON)
+
+# Same as above, but for the third-party tools.
+# Although these tools are targetted at development environments only,
+# the users are allowed to override the option to build by default.
+if(ANDROID OR IOS)
+ option(PNG_TOOLS "Build the libpng tools" OFF)
+else()
+ option(PNG_TOOLS "Build the libpng tools" ON)
+endif()
+
+# Maintain backwards compatibility with the deprecated option PNG_EXECUTABLES.
+option(PNG_EXECUTABLES "[Deprecated; please use PNG_TOOLS]" ON)
+if(NOT PNG_EXECUTABLES)
+ message(DEPRECATION "The option PNG_EXECUTABLES has been deprecated in favour of PNG_TOOLS")
+ if(PNG_TOOLS)
+ message(AUTHOR_WARNING "Setting PNG_TOOLS to ${PNG_EXECUTABLES}, "
+ "to stay compatible with PNG_EXECUTABLES")
+ set(PNG_TOOLS "${PNG_EXECUTABLES}")
+ endif()
+endif()
+
+# Allow the users to configure various compilation options.
+option(PNG_DEBUG "Enable debug output" OFF)
+option(PNG_HARDWARE_OPTIMIZATIONS "Enable hardware optimizations" ON)
+
+# Initialize and show the target architecture variable PNG_TARGET_ARCHITECTURE.
+#
+# NOTE:
+# On macOS, CMake sets CMAKE_SYSTEM_PROCESSOR to either "x86_64" or "arm64",
+# based upon the OS architecture, not the target architecture. As such, we need
+# to check CMAKE_OSX_ARCHITECTURES to identify which hardware-specific flags to
+# enable. Note that this will fail if you attempt to build a universal binary
+# in a single CMake invocation.
+if(APPLE AND CMAKE_OSX_ARCHITECTURES)
+ string(TOLOWER "${CMAKE_OSX_ARCHITECTURES}" PNG_TARGET_ARCHITECTURE)
+else()
+ string(TOLOWER "${CMAKE_SYSTEM_PROCESSOR}" PNG_TARGET_ARCHITECTURE)
+endif()
+message(STATUS "Building for target architecture: ${PNG_TARGET_ARCHITECTURE}")
+
+# Allow the users to specify a custom location of zlib.
+# With CMake 3.12 and newer, this option is no longer necessary.
+option(PNG_BUILD_ZLIB "[Deprecated; please use ZLIB_ROOT]" OFF)
+if(PNG_BUILD_ZLIB)
+ if("x${ZLIB_ROOT}" STREQUAL "x")
+ message(SEND_ERROR "The option PNG_BUILD_ZLIB=${PNG_BUILD_ZLIB} is no longer supported; "
+ "please use ZLIB_ROOT instead")
+ else()
+ message(SEND_ERROR "The option PNG_BUILD_ZLIB=${PNG_BUILD_ZLIB} is no longer supported; "
+ "using ZLIB_ROOT=\"${ZLIB_ROOT}\"")
+ endif()
+endif()
+
+# Find the prerequisite libraries.
+find_package(ZLIB REQUIRED)
+
+if(UNIX
+ AND NOT (APPLE OR BEOS OR HAIKU)
+ AND NOT EMSCRIPTEN)
+ find_library(M_LIBRARY m)
+ if(M_LIBRARY)
+ set(M_LIBRARY m)
+ else()
+ set(M_LIBRARY "")
+ endif()
+else()
+ # libm is not available or not needed.
+endif()
+
+if(PNG_HARDWARE_OPTIMIZATIONS)
+
+ # Set definitions and sources for ARM.
+ if(PNG_TARGET_ARCHITECTURE MATCHES "^(arm|aarch)")
+ if(PNG_TARGET_ARCHITECTURE MATCHES "^(arm64|aarch64)")
+ set(PNG_ARM_NEON_POSSIBLE_VALUES on off)
+ set(PNG_ARM_NEON
+ "on"
+ CACHE STRING "Enable ARM NEON optimizations: on|off; on is default")
+ else()
+ set(PNG_ARM_NEON_POSSIBLE_VALUES check on off)
+ set(PNG_ARM_NEON
+ "off"
+ CACHE STRING "Enable ARM NEON optimizations: check|on|off; off is default")
+ endif()
+ set_property(CACHE PNG_ARM_NEON
+ PROPERTY STRINGS ${PNG_ARM_NEON_POSSIBLE_VALUES})
+ list(FIND PNG_ARM_NEON_POSSIBLE_VALUES ${PNG_ARM_NEON} index)
+ if(index EQUAL -1)
+ message(FATAL_ERROR "PNG_ARM_NEON must be one of [${PNG_ARM_NEON_POSSIBLE_VALUES}]")
+ elseif(NOT PNG_ARM_NEON STREQUAL "off")
+ set(libpng_arm_sources
+ arm/arm_init.c
+ arm/filter_neon_intrinsics.c
+ arm/palette_neon_intrinsics.c)
+ if(PNG_ARM_NEON STREQUAL "on")
+ add_definitions(-DPNG_ARM_NEON_OPT=2)
+ elseif(PNG_ARM_NEON STREQUAL "check")
+ add_definitions(-DPNG_ARM_NEON_CHECK_SUPPORTED)
+ endif()
+ else()
+ add_definitions(-DPNG_ARM_NEON_OPT=0)
+ endif()
+ endif()
+
+ # Set definitions and sources for PowerPC.
+ if(PNG_TARGET_ARCHITECTURE MATCHES "^(powerpc|ppc64)")
+ set(PNG_POWERPC_VSX_POSSIBLE_VALUES on off)
+ set(PNG_POWERPC_VSX
+ "on"
+ CACHE STRING "Enable POWERPC VSX optimizations: on|off; on is default")
+ set_property(CACHE PNG_POWERPC_VSX
+ PROPERTY STRINGS ${PNG_POWERPC_VSX_POSSIBLE_VALUES})
+ list(FIND PNG_POWERPC_VSX_POSSIBLE_VALUES ${PNG_POWERPC_VSX} index)
+ if(index EQUAL -1)
+ message(FATAL_ERROR "PNG_POWERPC_VSX must be one of [${PNG_POWERPC_VSX_POSSIBLE_VALUES}]")
+ elseif(NOT PNG_POWERPC_VSX STREQUAL "off")
+ set(libpng_powerpc_sources
+ powerpc/powerpc_init.c
+ powerpc/filter_vsx_intrinsics.c)
+ if(PNG_POWERPC_VSX STREQUAL "on")
+ add_definitions(-DPNG_POWERPC_VSX_OPT=2)
+ endif()
+ else()
+ add_definitions(-DPNG_POWERPC_VSX_OPT=0)
+ endif()
+ endif()
+
+ # Set definitions and sources for Intel.
+ if(PNG_TARGET_ARCHITECTURE MATCHES "^(i[3-6]86|x86|amd64)")
+ set(PNG_INTEL_SSE_POSSIBLE_VALUES on off)
+ set(PNG_INTEL_SSE
+ "on"
+ CACHE STRING "Enable INTEL_SSE optimizations: on|off; on is default")
+ set_property(CACHE PNG_INTEL_SSE
+ PROPERTY STRINGS ${PNG_INTEL_SSE_POSSIBLE_VALUES})
+ list(FIND PNG_INTEL_SSE_POSSIBLE_VALUES ${PNG_INTEL_SSE} index)
+ if(index EQUAL -1)
+ message(FATAL_ERROR "PNG_INTEL_SSE must be one of [${PNG_INTEL_SSE_POSSIBLE_VALUES}]")
+ elseif(NOT PNG_INTEL_SSE STREQUAL "off")
+ set(libpng_intel_sources
+ intel/intel_init.c
+ intel/filter_sse2_intrinsics.c)
+ if(PNG_INTEL_SSE STREQUAL "on")
+ add_definitions(-DPNG_INTEL_SSE_OPT=1)
+ endif()
+ else()
+ add_definitions(-DPNG_INTEL_SSE_OPT=0)
+ endif()
+ endif()
+
+ # Set definitions and sources for MIPS.
+ if(PNG_TARGET_ARCHITECTURE MATCHES "^(mipsel|mips64el)")
+ set(PNG_MIPS_MSA_POSSIBLE_VALUES on off)
+ set(PNG_MIPS_MSA
+ "on"
+ CACHE STRING "Enable MIPS_MSA optimizations: on|off; on is default")
+ set_property(CACHE PNG_MIPS_MSA
+ PROPERTY STRINGS ${PNG_MIPS_MSA_POSSIBLE_VALUES})
+ list(FIND PNG_MIPS_MSA_POSSIBLE_VALUES ${PNG_MIPS_MSA} index_msa)
+ if(index_msa EQUAL -1)
+ message(FATAL_ERROR "PNG_MIPS_MSA must be one of [${PNG_MIPS_MSA_POSSIBLE_VALUES}]")
+ endif()
+
+ set(PNG_MIPS_MMI_POSSIBLE_VALUES on off)
+ set(PNG_MIPS_MMI
+ "on"
+ CACHE STRING "Enable MIPS_MMI optimizations: on|off; on is default")
+ set_property(CACHE PNG_MIPS_MMI
+ PROPERTY STRINGS ${PNG_MIPS_MMI_POSSIBLE_VALUES})
+ list(FIND PNG_MIPS_MMI_POSSIBLE_VALUES ${PNG_MIPS_MMI} index_mmi)
+ if(index_mmi EQUAL -1)
+ message(FATAL_ERROR "PNG_MIPS_MMI must be one of [${PNG_MIPS_MMI_POSSIBLE_VALUES}]")
+ endif()
+
+ if(PNG_MIPS_MSA STREQUAL "on" AND PNG_MIPS_MMI STREQUAL "on")
+ set(libpng_mips_sources
+ mips/mips_init.c
+ mips/filter_msa_intrinsics.c
+ mips/filter_mmi_inline_assembly.c)
+ add_definitions(-DPNG_MIPS_MSA_OPT=2)
+ add_definitions(-DPNG_MIPS_MMI_OPT=1)
+ elseif(PNG_MIPS_MSA STREQUAL "on")
+ set(libpng_mips_sources
+ mips/mips_init.c
+ mips/filter_msa_intrinsics.c)
+ add_definitions(-DPNG_MIPS_MSA_OPT=2)
+ add_definitions(-DPNG_MIPS_MMI_OPT=0)
+ elseif(PNG_MIPS_MMI STREQUAL "on")
+ set(libpng_mips_sources
+ mips/mips_init.c
+ mips/filter_mmi_inline_assembly.c)
+ add_definitions(-DPNG_MIPS_MSA_OPT=0)
+ add_definitions(-DPNG_MIPS_MMI_OPT=1)
+ else()
+ add_definitions(-DPNG_MIPS_MSA_OPT=0)
+ add_definitions(-DPNG_MIPS_MMI_OPT=0)
+ endif()
+ endif()
+
+ # Set definitions and sources for LoongArch.
+ if(PNG_TARGET_ARCHITECTURE MATCHES "^(loongarch)")
+ include(CheckCCompilerFlag)
+ set(PNG_LOONGARCH_LSX_POSSIBLE_VALUES on off)
+ set(PNG_LOONGARCH_LSX
+ "on"
+ CACHE STRING "Enable LOONGARCH_LSX optimizations: on|off; on is default")
+ set_property(CACHE PNG_LOONGARCH_LSX
+ PROPERTY STRINGS ${PNG_LOONGARCH_LSX_POSSIBLE_VALUES})
+ list(FIND PNG_LOONGARCH_LSX_POSSIBLE_VALUES ${PNG_LOONGARCH_LSX} index)
+ if(index EQUAL -1)
+ message(FATAL_ERROR "PNG_LOONGARCH_LSX must be one of [${PNG_LOONGARCH_LSX_POSSIBLE_VALUES}]")
+ elseif(NOT PNG_LOONGARCH_LSX STREQUAL "off")
+ check_c_compiler_flag("-mlsx" COMPILER_SUPPORTS_LSX)
+ if(COMPILER_SUPPORTS_LSX)
+ set(libpng_loongarch_sources
+ loongarch/loongarch_lsx_init.c
+ loongarch/filter_lsx_intrinsics.c)
+ set_source_files_properties(${libpng_loongarch_sources}
+ PROPERTIES COMPILE_FLAGS "-mlsx")
+ add_definitions(-DPNG_LOONGARCH_LSX_OPT=1)
+ else()
+ message(FATAL_ERROR "This compiler does not support the -mlsx option")
+ endif()
+ else()
+ add_definitions(-DPNG_LOONGARCH_LSX_OPT=0)
+ endif()
+ endif()
+
+ # Set definitions and sources for RISC-V.
+ if(PNG_TARGET_ARCHITECTURE MATCHES "^(riscv)")
+ include(CheckCCompilerFlag)
+ set(PNG_RISCV_RVV_POSSIBLE_VALUES check on off)
+ set(PNG_RISCV_RVV "off"
+ CACHE STRING "Enable RISC-V Vector optimizations: check|on|off; off is default")
+ set_property(CACHE PNG_RISCV_RVV
+ PROPERTY STRINGS ${PNG_RISCV_RVV_POSSIBLE_VALUES})
+ list(FIND PNG_RISCV_RVV_POSSIBLE_VALUES ${PNG_RISCV_RVV} index)
+ if(index EQUAL -1)
+ message(FATAL_ERROR "PNG_RISCV_RVV must be one of [${PNG_RISCV_RVV_POSSIBLE_VALUES}]")
+ elseif(NOT PNG_RISCV_RVV STREQUAL "off")
+ check_c_compiler_flag("-march=rv64gv1p0" COMPILER_SUPPORTS_RVV)
+ if(NOT COMPILER_SUPPORTS_RVV)
+ message(FATAL_ERROR "Compiler does not support -march=rv64gv1p0 option")
+ endif()
+ set(libpng_riscv_sources
+ riscv/filter_rvv_intrinsics.c
+ riscv/riscv_init.c)
+ if(PNG_RISCV_RVV STREQUAL "on")
+ add_definitions(-DPNG_RISCV_RVV_OPT=2)
+ elseif(PNG_RISCV_RVV STREQUAL "check")
+ add_definitions(-DPNG_RISCV_RVV_CHECK_SUPPORTED)
+ endif()
+ else()
+ add_definitions(-DPNG_RISCV_RVV_OPT=0)
+ endif()
+ endif()
+
+else(PNG_HARDWARE_OPTIMIZATIONS)
+
+ # Set definitions and sources for ARM.
+ if(PNG_TARGET_ARCHITECTURE MATCHES "^(arm|aarch)")
+ add_definitions(-DPNG_ARM_NEON_OPT=0)
+ endif()
+
+ # Set definitions and sources for PowerPC.
+ if(PNG_TARGET_ARCHITECTURE MATCHES "^(powerpc|ppc64)")
+ add_definitions(-DPNG_POWERPC_VSX_OPT=0)
+ endif()
+
+ # Set definitions and sources for Intel.
+ if(PNG_TARGET_ARCHITECTURE MATCHES "^(i[3-6]86|x86|amd64)")
+ add_definitions(-DPNG_INTEL_SSE_OPT=0)
+ endif()
+
+ # Set definitions and sources for MIPS.
+ if(PNG_TARGET_ARCHITECTURE MATCHES "^(mipsel|mips64el)")
+ add_definitions(-DPNG_MIPS_MSA_OPT=0)
+ endif()
+
+ # Set definitions and sources for LoongArch.
+ if(PNG_TARGET_ARCHITECTURE MATCHES "^(loongarch)")
+ add_definitions(-DPNG_LOONGARCH_LSX_OPT=0)
+ endif()
+
+ # Set definitions and sources for RISC-V.
+ if(PNG_TARGET_ARCHITECTURE MATCHES "^(riscv)")
+ add_definitions(-DPNG_RISCV_RVV_OPT=0)
+ endif()
+
+endif(PNG_HARDWARE_OPTIMIZATIONS)
+
+option(ld-version-script "Enable linker version script" ON)
+if(ld-version-script AND NOT (ANDROID OR APPLE))
+ # Check if LD supports linker scripts.
+ file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/conftest.map" "
+VERS_1 { global: sym1; local: *; };
+VERS_2 { global: sym2; main; } VERS_1;
+")
+ set(_SAVED_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
+ if(NOT CMAKE_HOST_SOLARIS)
+ # Avoid using CMAKE_SHARED_LIBRARY_C_FLAGS in version script checks on
+ # Solaris, because of an incompatibility with the Solaris link editor.
+ list(APPEND CMAKE_REQUIRED_FLAGS ${CMAKE_SHARED_LIBRARY_C_FLAGS})
+ endif()
+ list(APPEND CMAKE_REQUIRED_FLAGS
+ "-Wl,--version-script='${CMAKE_CURRENT_BINARY_DIR}/conftest.map'")
+ check_c_source_compiles("
+void sym1(void) {}
+void sym2(void) {}
+int main(void) { return 0; }
+" HAVE_LD_VERSION_SCRIPT)
+ if(NOT HAVE_LD_VERSION_SCRIPT)
+ set(CMAKE_REQUIRED_FLAGS ${_SAVED_CMAKE_REQUIRED_FLAGS})
+ if(NOT CMAKE_HOST_SOLARIS)
+ # Again, avoid using CMAKE_SHARED_LIBRARY_C_FLAGS in version script
+ # checks on Solaris.
+ list(APPEND CMAKE_REQUIRED_FLAGS ${CMAKE_SHARED_LIBRARY_C_FLAGS})
+ endif()
+ list(APPEND CMAKE_REQUIRED_FLAGS "-Wl,-M -Wl,${CMAKE_CURRENT_BINARY_DIR}/conftest.map")
+ check_c_source_compiles("
+void sym1(void) {}
+void sym2(void) {}
+int main(void) { return 0; }
+" HAVE_SOLARIS_LD_VERSION_SCRIPT)
+ endif()
+ set(CMAKE_REQUIRED_FLAGS ${_SAVED_CMAKE_REQUIRED_FLAGS})
+ file(REMOVE "${CMAKE_CURRENT_BINARY_DIR}/conftest.map")
+endif()
+
+if(PNG_LIBCONF_HEADER STREQUAL "")
+ # No custom configuration header file has been specified, so we build it
+ # from our DFA files and (optionally) out of the user-supplied DFA file.
+ # Find an AWK language processor.
+ # Start with specific AWK implementations like gawk and nawk, which are
+ # known to work with our scripts, then fall back to the system awk.
+ find_program(AWK NAMES gawk nawk awk)
+ if(AWK)
+ message(STATUS "Found AWK program: ${AWK}")
+ else()
+ message(STATUS "Could not find an AWK-compatible program")
+ endif()
+endif()
+
+# Include the internal module PNGCheckLibconf.cmake
+# include(${CMAKE_CURRENT_SOURCE_DIR}/scripts/cmake/PNGCheckLibconf.cmake)
+
+if(NOT PNG_LIBCONF_HEADER STREQUAL "")
+ # Configure libpng with the user-defined pnglibconf.h file.
+ configure_file("${PNG_LIBCONF_HEADER}"
+ ${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h
+ @ONLY)
+ add_custom_target(png_genfiles)
+elseif(NOT AWK)
+ # No AWK program available to generate pnglibconf.h.
+ # Configure libpng with pnglibconf.h.prebuilt.
+ configure_file("${PNG_LIBCONF_HEADER_PREBUILT}"
+ ${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h
+ @ONLY)
+ add_custom_target(png_genfiles)
+else()
+
+ # Include the internal module PNGGenConfig.cmake
+ include(${CMAKE_CURRENT_SOURCE_DIR}/scripts/cmake/PNGGenConfig.cmake)
+
+ # Work around a limitation of various Windows AWK programs that are
+ # unable to process CRLF-terminated AWK scripts.
+ # Copy these AWK scripts to a temporary location, converting their
+ # line endings from Windows (CRLF) to Unix (LF) at the destination.
+ configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/checksym.awk
+ ${CMAKE_CURRENT_BINARY_DIR}/scripts/checksym.awk
+ @ONLY
+ NEWLINE_STYLE LF)
+ configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/options.awk
+ ${CMAKE_CURRENT_BINARY_DIR}/scripts/options.awk
+ @ONLY
+ NEWLINE_STYLE LF)
+ configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/dfn.awk
+ ${CMAKE_CURRENT_BINARY_DIR}/scripts/dfn.awk
+ @ONLY
+ NEWLINE_STYLE LF)
+
+ # Generate scripts/pnglibconf.h
+ generate_source(OUTPUT "scripts/pnglibconf.c"
+ DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.dfa"
+ "${CMAKE_CURRENT_BINARY_DIR}/scripts/options.awk"
+ "${CMAKE_CURRENT_SOURCE_DIR}/pngconf.h")
+ add_custom_target(png_scripts_pnglibconf_c
+ DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/scripts/pnglibconf.c")
+
+ # Generate pnglibconf.c
+ generate_source(OUTPUT "pnglibconf.c"
+ DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.dfa"
+ "${CMAKE_CURRENT_BINARY_DIR}/scripts/options.awk"
+ "${CMAKE_CURRENT_SOURCE_DIR}/pngconf.h")
+ add_custom_target(pnglibconf_c
+ DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.c")
+
+ if(PNG_PREFIX)
+ set(PNGLIBCONF_H_EXTRA_DEPENDS
+ "${CMAKE_CURRENT_BINARY_DIR}/scripts/prefix.out"
+ "${CMAKE_CURRENT_SOURCE_DIR}/scripts/macro.lst")
+ set(PNGPREFIX_H_EXTRA_DEPENDS
+ "${CMAKE_CURRENT_BINARY_DIR}/scripts/intprefix.out")
+ endif()
+
+ generate_out(INPUT "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.c"
+ OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.out"
+ DEPENDS pnglibconf_c)
+ add_custom_target(pnglibconf_out
+ DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.out")
+
+ # Generate pnglibconf.h
+ generate_source(OUTPUT "pnglibconf.h"
+ DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.out"
+ pnglibconf_out
+ ${PNGLIBCONF_H_EXTRA_DEPENDS})
+ add_custom_target(pnglibconf_h
+ DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h")
+
+ generate_out(INPUT "${CMAKE_CURRENT_SOURCE_DIR}/scripts/intprefix.c"
+ OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/intprefix.out"
+ DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h"
+ pnglibconf_h)
+ add_custom_target(png_scripts_intprefix_out
+ DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/scripts/intprefix.out")
+
+ generate_out(INPUT "${CMAKE_CURRENT_SOURCE_DIR}/scripts/prefix.c"
+ OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/prefix.out"
+ DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/png.h"
+ "${CMAKE_CURRENT_SOURCE_DIR}/pngconf.h"
+ "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.out"
+ pnglibconf_out)
+ add_custom_target(png_scripts_prefix_out
+ DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/scripts/prefix.out")
+
+ # Generate pngprefix.h
+ generate_source(OUTPUT "pngprefix.h"
+ DEPENDS ${PNGPREFIX_H_EXTRA_DEPENDS})
+ add_custom_target(pngprefix_h
+ DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/pngprefix.h")
+
+ generate_out(INPUT "${CMAKE_CURRENT_SOURCE_DIR}/scripts/sym.c"
+ OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/sym.out"
+ DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h"
+ pnglibconf_h)
+ add_custom_target(png_scripts_sym_out
+ DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/scripts/sym.out")
+
+ generate_out(INPUT "${CMAKE_CURRENT_SOURCE_DIR}/scripts/symbols.c"
+ OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.out"
+ DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/png.h"
+ "${CMAKE_CURRENT_SOURCE_DIR}/pngconf.h"
+ "${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.h.prebuilt")
+ add_custom_target(png_scripts_symbols_out
+ DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.out")
+
+ generate_out(INPUT "${CMAKE_CURRENT_SOURCE_DIR}/scripts/vers.c"
+ OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/vers.out"
+ DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/png.h"
+ "${CMAKE_CURRENT_SOURCE_DIR}/pngconf.h"
+ "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h"
+ pnglibconf_h)
+ add_custom_target(png_scripts_vers_out
+ DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/scripts/vers.out")
+
+ generate_chk(INPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.out"
+ OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.chk"
+ DEPENDS png_scripts_symbols_out
+ "${CMAKE_CURRENT_BINARY_DIR}/scripts/checksym.awk"
+ "${CMAKE_CURRENT_SOURCE_DIR}/scripts/symbols.def")
+
+ add_custom_target(png_scripts_symbols_chk
+ DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.chk")
+
+ generate_copy(INPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/sym.out"
+ OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/libpng.sym"
+ DEPENDS png_scripts_sym_out)
+ generate_copy(INPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/vers.out"
+ OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/libpng.vers"
+ DEPENDS png_scripts_vers_out)
+
+ add_custom_target(png_genvers
+ DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/libpng.vers")
+ add_custom_target(png_gensym
+ DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/libpng.sym")
+
+ add_custom_target(png_genprebuilt
+ COMMAND "${CMAKE_COMMAND}"
+ "-DOUTPUT=scripts/pnglibconf.h.prebuilt"
+ -P "${CMAKE_CURRENT_BINARY_DIR}/scripts/cmake/gensrc.cmake"
+ WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}")
+
+ # A single target handles generation of all generated files.
+ add_custom_target(png_genfiles
+ DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/libpng.sym"
+ png_gensym
+ "${CMAKE_CURRENT_BINARY_DIR}/libpng.vers"
+ png_genvers
+ "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.c"
+ pnglibconf_c
+ "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h"
+ pnglibconf_h
+ "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.out"
+ pnglibconf_out
+ "${CMAKE_CURRENT_BINARY_DIR}/pngprefix.h"
+ pngprefix_h
+ "${CMAKE_CURRENT_BINARY_DIR}/scripts/intprefix.out"
+ png_scripts_intprefix_out
+ "${CMAKE_CURRENT_BINARY_DIR}/scripts/pnglibconf.c"
+ png_scripts_pnglibconf_c
+ "${CMAKE_CURRENT_BINARY_DIR}/scripts/prefix.out"
+ png_scripts_prefix_out
+ "${CMAKE_CURRENT_BINARY_DIR}/scripts/sym.out"
+ png_scripts_sym_out
+ "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.chk"
+ png_scripts_symbols_chk
+ "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.out"
+ png_scripts_symbols_out
+ "${CMAKE_CURRENT_BINARY_DIR}/scripts/vers.out"
+ png_scripts_vers_out)
+endif()
+
+# List the source code files.
+set(libpng_public_hdrs
+ png.h
+ pngconf.h
+ "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h"
+)
+set(libpng_private_hdrs
+ pngpriv.h
+ pngdebug.h
+ pnginfo.h
+ pngstruct.h
+)
+if(AWK)
+ list(APPEND libpng_private_hdrs "${CMAKE_CURRENT_BINARY_DIR}/pngprefix.h")
+endif()
+set(libpng_sources
+ ${libpng_public_hdrs}
+ ${libpng_private_hdrs}
+ png.c
+ pngerror.c
+ pngget.c
+ pngmem.c
+ pngpread.c
+ pngread.c
+ pngrio.c
+ pngrtran.c
+ pngrutil.c
+ pngset.c
+ pngtrans.c
+ pngwio.c
+ pngwrite.c
+ pngwtran.c
+ pngwutil.c
+ ${libpng_arm_sources}
+ ${libpng_intel_sources}
+ ${libpng_mips_sources}
+ ${libpng_powerpc_sources}
+ ${libpng_loongarch_sources}
+ ${libpng_riscv_sources}
+)
+
+set(pngtest_sources
+ pngtest.c
+)
+set(pngfix_sources
+ contrib/tools/pngfix.c
+)
+set(png_fix_itxt_sources
+ contrib/tools/png-fix-itxt.c
+)
+
+if(MSVC OR (WIN32 AND (CMAKE_C_COMPILER_ID MATCHES "Clang")))
+ add_definitions(-D_CRT_NONSTDC_NO_DEPRECATE)
+ add_definitions(-D_CRT_SECURE_NO_DEPRECATE)
+endif()
+
+if(PNG_DEBUG)
+ add_definitions(-DPNG_DEBUG)
+endif()
+
+# Now build our targets.
+
+# Initialize the list of libpng library targets.
+set(PNG_LIBRARY_TARGETS "")
+
+# Initialize the libpng library file names.
+if(UNIX
+ OR (WIN32 AND NOT CMAKE_SHARED_LIBRARY_PREFIX STREQUAL "")
+ OR (WIN32 AND NOT CMAKE_STATIC_LIBRARY_PREFIX STREQUAL ""))
+ # We are on a Unix or Unix-like toolchain like the GNU toolchain on Windows.
+ # Library file names are expected to have an implicit prefix such as "lib".
+ # Let CMake prepend and append its usual prefixes and suffixes by default.
+ set(PNG_SHARED_OUTPUT_NAME "png${PNGLIB_ABI_VERSION}")
+ set(PNG_STATIC_OUTPUT_NAME "png${PNGLIB_ABI_VERSION}")
+else()
+ # We are, most likely, on a Windows toolchain like MSVC, Clang on Windows,
+ # Borland/Embarcadero, etc. We need to specify the "libpng" name explicitly.
+ # We also need to use a custom suffix, in order to distinguish between the
+ # shared import library name and the static library name.
+ set(PNG_SHARED_OUTPUT_NAME "libpng${PNGLIB_ABI_VERSION}")
+ set(PNG_STATIC_OUTPUT_NAME "libpng${PNGLIB_ABI_VERSION}_static")
+endif()
+
+configure_file(
+ ${PNG_LIBCONF_HEADER}
+ ${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h
+ COPYONLY
+)
+
+if(PNG_SHARED)
+ add_library(png_shared SHARED ${libpng_sources})
+ add_dependencies(png_shared png_genfiles)
+ list(APPEND PNG_LIBRARY_TARGETS png_shared)
+ set_target_properties(png_shared
+ PROPERTIES OUTPUT_NAME "${PNG_SHARED_OUTPUT_NAME}"
+ DEBUG_POSTFIX "${PNG_DEBUG_POSTFIX}"
+ VERSION "${PNGLIB_SHARED_VERSION}"
+ SOVERSION "${PNGLIB_ABI_VERSION}")
+ if(UNIX AND AWK)
+ if(HAVE_LD_VERSION_SCRIPT)
+ set_target_properties(png_shared
+ PROPERTIES LINK_FLAGS "-Wl,--version-script='${CMAKE_CURRENT_BINARY_DIR}/libpng.vers'")
+ elseif(HAVE_SOLARIS_LD_VERSION_SCRIPT)
+ set_target_properties(png_shared
+ PROPERTIES LINK_FLAGS "-Wl,-M -Wl,'${CMAKE_CURRENT_BINARY_DIR}/libpng.vers'")
+ endif()
+ endif()
+ if(APPLE)
+ # Avoid CMake's implicit compile definition "png_shared_EXPORTS".
+ set_target_properties(png_shared
+ PROPERTIES DEFINE_SYMBOL "")
+ elseif(WIN32)
+ # Use the explicit compile definition "PNG_BUILD_DLL" for Windows DLLs.
+ set_target_properties(png_shared
+ PROPERTIES DEFINE_SYMBOL PNG_BUILD_DLL)
+ endif()
+ target_include_directories(png_shared
+ PUBLIC $)
+ target_include_directories(png_shared
+ PUBLIC $)
+ target_include_directories(png_shared
+ SYSTEM
+ INTERFACE $)
+ target_link_libraries(png_shared
+ PUBLIC ZLIB::ZLIB ${M_LIBRARY})
+endif()
+
+if(PNG_STATIC)
+ add_library(png_static STATIC ${libpng_sources})
+ add_dependencies(png_static png_genfiles)
+ list(APPEND PNG_LIBRARY_TARGETS png_static)
+ set_target_properties(png_static
+ PROPERTIES OUTPUT_NAME "${PNG_STATIC_OUTPUT_NAME}"
+ DEBUG_POSTFIX "${PNG_DEBUG_POSTFIX}")
+ target_include_directories(png_static
+ PUBLIC $)
+ target_include_directories(png_static
+ PUBLIC $)
+ target_include_directories(png_static
+ SYSTEM
+ INTERFACE $)
+ target_link_libraries(png_static
+ PUBLIC ZLIB::ZLIB ${M_LIBRARY})
+endif()
+
+if(PNG_FRAMEWORK AND NOT APPLE)
+ message(AUTHOR_WARNING "Setting PNG_FRAMEWORK to OFF, as it only applies to Apple systems")
+ set(PNG_FRAMEWORK OFF)
+endif()
+
+if(PNG_FRAMEWORK)
+ add_library(png_framework SHARED ${libpng_sources})
+ add_dependencies(png_framework png_genfiles)
+ list(APPEND PNG_LIBRARY_TARGETS png_framework)
+ set_target_properties(png_framework
+ PROPERTIES FRAMEWORK TRUE
+ FRAMEWORK_VERSION "${PNGLIB_VERSION}"
+ MACOSX_FRAMEWORK_SHORT_VERSION_STRING "${PNGLIB_MAJOR}.${PNGLIB_MINOR}"
+ MACOSX_FRAMEWORK_BUNDLE_VERSION "${PNGLIB_VERSION}"
+ MACOSX_FRAMEWORK_IDENTIFIER "org.libpng.libpng"
+ XCODE_ATTRIBUTE_INSTALL_PATH "@rpath"
+ PUBLIC_HEADER "${libpng_public_hdrs}"
+ OUTPUT_NAME "png"
+ DEBUG_POSTFIX "${PNG_DEBUG_POSTFIX}")
+ # Avoid CMake's implicit compile definition "-Dpng_framework_EXPORTS".
+ set_target_properties(png_framework
+ PROPERTIES DEFINE_SYMBOL "")
+ target_include_directories(png_framework
+ PUBLIC $)
+ target_include_directories(png_framework
+ PUBLIC $)
+ target_include_directories(png_framework
+ SYSTEM
+ INTERFACE $)
+ target_link_libraries(png_framework
+ PUBLIC ZLIB::ZLIB ${M_LIBRARY})
+endif()
+
+if(NOT PNG_LIBRARY_TARGETS)
+ message(SEND_ERROR "No library variant selected to build. "
+ "Please enable at least one of the following options: "
+ "PNG_SHARED, PNG_STATIC, PNG_FRAMEWORK")
+endif()
+
+if(PNG_SHARED AND PNG_TOOLS)
+ add_executable(pngfix ${pngfix_sources})
+ target_link_libraries(pngfix
+ PRIVATE png_shared)
+ set(PNG_BIN_TARGETS pngfix)
+
+ add_executable(png-fix-itxt ${png_fix_itxt_sources})
+ target_link_libraries(png-fix-itxt
+ PRIVATE ZLIB::ZLIB ${M_LIBRARY})
+ list(APPEND PNG_BIN_TARGETS png-fix-itxt)
+endif()
+
+# Create a symlink that points to a target file (if symlinking is possible),
+# or make a copy of the target file (if symlinking is not possible):
+# create_symlink( [FILE | TARGET ])
+function(create_symlink DEST_FILE)
+ # TODO:
+ # Replace this implementation with CMake's built-in create_symlink function,
+ # which has been fully functional on all platforms, including Windows, since
+ # CMake version 3.13.
+ cmake_parse_arguments(_SYM "" "FILE;TARGET" "" ${ARGN})
+ if(NOT _SYM_FILE AND NOT _SYM_TARGET)
+ message(FATAL_ERROR "create_symlink: Missing arguments: FILE or TARGET")
+ endif()
+ if(_SYM_FILE AND _SYM_TARGET)
+ message(FATAL_ERROR "create_symlink: Mutually-exlusive arguments:"
+ "FILE (${_SYM_FILE}) and TARGET (${_SYM_TARGET})")
+ endif()
+
+ if(_SYM_FILE)
+ # If we don't need to symlink something that's coming from a build target,
+ # we can go ahead and symlink/copy at configure time.
+ if(CMAKE_HOST_WIN32 AND NOT CYGWIN)
+ execute_process(COMMAND "${CMAKE_COMMAND}"
+ -E copy_if_different
+ ${_SYM_FILE} ${DEST_FILE}
+ WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}")
+ else()
+ execute_process(COMMAND "${CMAKE_COMMAND}"
+ -E create_symlink
+ ${_SYM_FILE} ${DEST_FILE}
+ WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}")
+ endif()
+ endif()
+
+ if(_SYM_TARGET)
+ # We need to use generator expressions, which can be a bit tricky.
+ # For simplicity, make the symlink a POST_BUILD step, and use the TARGET
+ # signature of add_custom_command.
+ if(CMAKE_HOST_WIN32 AND NOT CYGWIN)
+ add_custom_command(TARGET ${_SYM_TARGET}
+ POST_BUILD
+ COMMAND "${CMAKE_COMMAND}"
+ -E copy_if_different
+ $/$
+ $/${DEST_FILE})
+ else()
+ add_custom_command(TARGET ${_SYM_TARGET}
+ POST_BUILD
+ COMMAND "${CMAKE_COMMAND}"
+ -E create_symlink
+ $
+ $/${DEST_FILE})
+ endif()
+ endif()
+endfunction()
+
+# Create source generation scripts.
+# configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/cmake/genchk.cmake.in
+# ${CMAKE_CURRENT_BINARY_DIR}/scripts/cmake/genchk.cmake
+# @ONLY)
+# configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/cmake/genout.cmake.in
+# ${CMAKE_CURRENT_BINARY_DIR}/scripts/cmake/genout.cmake
+# @ONLY)
+# configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/cmake/gensrc.cmake.in
+# ${CMAKE_CURRENT_BINARY_DIR}/scripts/cmake/gensrc.cmake
+# @ONLY)
+
+# libpng is a library so default to 'lib'
+if(NOT DEFINED CMAKE_INSTALL_LIBDIR)
+ set(CMAKE_INSTALL_LIBDIR lib)
+endif()
+
+# Create pkgconfig files.
+# We use the same files like ./configure, so we have to set its vars.
+# Only do this on Windows for Cygwin - the files don't make much sense
+# outside of a UNIX look-alike.
+if(NOT WIN32 OR CYGWIN OR MINGW)
+ set(prefix ${CMAKE_INSTALL_PREFIX})
+ set(exec_prefix ${CMAKE_INSTALL_PREFIX})
+ set(libdir ${CMAKE_INSTALL_FULL_LIBDIR})
+ set(includedir ${CMAKE_INSTALL_FULL_INCLUDEDIR})
+ set(LIBS "-lz -lm")
+ configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng.pc.in
+ ${CMAKE_CURRENT_BINARY_DIR}/libpng${PNGLIB_ABI_VERSION}.pc
+ @ONLY)
+ create_symlink(libpng.pc FILE libpng${PNGLIB_ABI_VERSION}.pc)
+ configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng-config.in
+ ${CMAKE_CURRENT_BINARY_DIR}/libpng${PNGLIB_ABI_VERSION}-config
+ @ONLY)
+ create_symlink(libpng-config FILE libpng${PNGLIB_ABI_VERSION}-config)
+endif()
+
+# Install.
+if(NOT SKIP_INSTALL_LIBRARIES AND NOT SKIP_INSTALL_ALL)
+ install(TARGETS ${PNG_LIBRARY_TARGETS}
+ EXPORT libpng
+ RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+ LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+ ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+ FRAMEWORK DESTINATION ${CMAKE_INSTALL_LIBDIR})
+
+ if(PNG_SHARED)
+ # Create a symlink for libpng.dll.a => libpng16.dll.a on Cygwin
+ if(NOT WIN32 OR CYGWIN OR MINGW)
+ create_symlink(libpng${CMAKE_SHARED_LIBRARY_SUFFIX} TARGET png_shared)
+ install(FILES $/libpng${CMAKE_SHARED_LIBRARY_SUFFIX}
+ DESTINATION ${CMAKE_INSTALL_LIBDIR})
+ endif()
+ endif()
+
+ if(PNG_STATIC)
+ if(NOT WIN32 OR CYGWIN OR MINGW)
+ create_symlink(libpng${CMAKE_STATIC_LIBRARY_SUFFIX} TARGET png_static)
+ install(FILES $/libpng${CMAKE_STATIC_LIBRARY_SUFFIX}
+ DESTINATION ${CMAKE_INSTALL_LIBDIR})
+ endif()
+ endif()
+endif()
+
+if(NOT SKIP_INSTALL_HEADERS AND NOT SKIP_INSTALL_ALL)
+ install(FILES ${libpng_public_hdrs}
+ DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+ install(FILES ${libpng_public_hdrs}
+ DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/libpng${PNGLIB_ABI_VERSION})
+endif()
+if(NOT SKIP_INSTALL_EXECUTABLES AND NOT SKIP_INSTALL_ALL)
+ if(NOT WIN32 OR CYGWIN OR MINGW)
+ install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng-config
+ DESTINATION ${CMAKE_INSTALL_BINDIR})
+ install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng${PNGLIB_ABI_VERSION}-config
+ DESTINATION ${CMAKE_INSTALL_BINDIR})
+ endif()
+endif()
+
+if(NOT SKIP_INSTALL_PROGRAMS AND NOT SKIP_INSTALL_ALL)
+ install(TARGETS ${PNG_BIN_TARGETS}
+ RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+endif()
+
+if(NOT SKIP_INSTALL_FILES AND NOT SKIP_INSTALL_ALL)
+ # Install the man pages.
+ install(FILES libpng.3 libpngpf.3
+ DESTINATION ${CMAKE_INSTALL_MANDIR}/man3)
+ install(FILES png.5
+ DESTINATION ${CMAKE_INSTALL_MANDIR}/man5)
+ # Install the pkg-config files.
+ if(NOT CMAKE_HOST_WIN32 OR CYGWIN OR MINGW)
+ install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng.pc
+ DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
+ install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng-config
+ DESTINATION ${CMAKE_INSTALL_BINDIR})
+ install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${PNGLIB_ABI_VERSION}.pc
+ DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
+ install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng${PNGLIB_ABI_VERSION}-config
+ DESTINATION ${CMAKE_INSTALL_BINDIR})
+ endif()
+endif()
+
+# Create an export file that CMake users can include() to import our targets.
+if(NOT SKIP_INSTALL_EXPORT AND NOT SKIP_INSTALL_ALL)
+ install(EXPORT libpng
+ DESTINATION ${CMAKE_INSTALL_LIBDIR}/libpng
+ FILE libpng${PNGLIB_ABI_VERSION}.cmake)
+endif()
+
+# Create a CMake Config File that can be used via find_package(PNG CONFIG)
+if(NOT SKIP_INSTALL_CONFIG_FILE AND NOT SKIP_INSTALL_ALL)
+ install(TARGETS ${PNG_LIBRARY_TARGETS}
+ EXPORT PNGTargets
+ RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+ LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+ ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+ FRAMEWORK DESTINATION ${CMAKE_INSTALL_LIBDIR})
+
+ include(CMakePackageConfigHelpers)
+ write_basic_package_version_file(PNGConfigVersion.cmake
+ VERSION ${PNGLIB_VERSION}
+ COMPATIBILITY SameMinorVersion)
+
+ install(EXPORT PNGTargets
+ FILE PNGTargets.cmake
+ NAMESPACE PNG::
+ DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/PNG)
+
+ install(FILES ${CMAKE_CURRENT_SOURCE_DIR}/scripts/cmake/PNGConfig.cmake
+ ${CMAKE_CURRENT_BINARY_DIR}/PNGConfigVersion.cmake
+ DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/PNG)
+endif()
+
+# TODO: Create MSVC import lib for MinGW-compiled shared lib.
+# pexports libpng.dll > libpng.def
+# lib /def:libpng.def /machine:x86
diff --git a/libs/imagequant/external/libpng/LICENSE b/libs/imagequant/external/libpng/LICENSE
new file mode 100644
index 00000000..ea6df986
--- /dev/null
+++ b/libs/imagequant/external/libpng/LICENSE
@@ -0,0 +1,134 @@
+COPYRIGHT NOTICE, DISCLAIMER, and LICENSE
+=========================================
+
+PNG Reference Library License version 2
+---------------------------------------
+
+ * Copyright (c) 1995-2025 The PNG Reference Library Authors.
+ * Copyright (c) 2018-2025 Cosmin Truta.
+ * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson.
+ * Copyright (c) 1996-1997 Andreas Dilger.
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+
+The software is supplied "as is", without warranty of any kind,
+express or implied, including, without limitation, the warranties
+of merchantability, fitness for a particular purpose, title, and
+non-infringement. In no event shall the Copyright owners, or
+anyone distributing the software, be liable for any damages or
+other liability, whether in contract, tort or otherwise, arising
+from, out of, or in connection with the software, or the use or
+other dealings in the software, even if advised of the possibility
+of such damage.
+
+Permission is hereby granted to use, copy, modify, and distribute
+this software, or portions hereof, for any purpose, without fee,
+subject to the following restrictions:
+
+ 1. The origin of this software must not be misrepresented; you
+ must not claim that you wrote the original software. If you
+ use this software in a product, an acknowledgment in the product
+ documentation would be appreciated, but is not required.
+
+ 2. Altered source versions must be plainly marked as such, and must
+ not be misrepresented as being the original software.
+
+ 3. This Copyright notice may not be removed or altered from any
+ source or altered source distribution.
+
+
+PNG Reference Library License version 1 (for libpng 0.5 through 1.6.35)
+-----------------------------------------------------------------------
+
+libpng versions 1.0.7, July 1, 2000, through 1.6.35, July 15, 2018 are
+Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson, are
+derived from libpng-1.0.6, and are distributed according to the same
+disclaimer and license as libpng-1.0.6 with the following individuals
+added to the list of Contributing Authors:
+
+ Simon-Pierre Cadieux
+ Eric S. Raymond
+ Mans Rullgard
+ Cosmin Truta
+ Gilles Vollant
+ James Yu
+ Mandar Sahastrabuddhe
+ Google Inc.
+ Vadim Barkov
+
+and with the following additions to the disclaimer:
+
+ There is no warranty against interference with your enjoyment of
+ the library or against infringement. There is no warranty that our
+ efforts or the library will fulfill any of your particular purposes
+ or needs. This library is provided with all faults, and the entire
+ risk of satisfactory quality, performance, accuracy, and effort is
+ with the user.
+
+Some files in the "contrib" directory and some configure-generated
+files that are distributed with libpng have other copyright owners, and
+are released under other open source licenses.
+
+libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
+Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
+libpng-0.96, and are distributed according to the same disclaimer and
+license as libpng-0.96, with the following individuals added to the
+list of Contributing Authors:
+
+ Tom Lane
+ Glenn Randers-Pehrson
+ Willem van Schaik
+
+libpng versions 0.89, June 1996, through 0.96, May 1997, are
+Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
+and are distributed according to the same disclaimer and license as
+libpng-0.88, with the following individuals added to the list of
+Contributing Authors:
+
+ John Bowler
+ Kevin Bracey
+ Sam Bushell
+ Magnus Holmgren
+ Greg Roelofs
+ Tom Tanner
+
+Some files in the "scripts" directory have other copyright owners,
+but are released under this license.
+
+libpng versions 0.5, May 1995, through 0.88, January 1996, are
+Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+
+For the purposes of this copyright and license, "Contributing Authors"
+is defined as the following set of individuals:
+
+ Andreas Dilger
+ Dave Martindale
+ Guy Eric Schalnat
+ Paul Schmidt
+ Tim Wegner
+
+The PNG Reference Library is supplied "AS IS". The Contributing
+Authors and Group 42, Inc. disclaim all warranties, expressed or
+implied, including, without limitation, the warranties of
+merchantability and of fitness for any purpose. The Contributing
+Authors and Group 42, Inc. assume no liability for direct, indirect,
+incidental, special, exemplary, or consequential damages, which may
+result from the use of the PNG Reference Library, even if advised of
+the possibility of such damage.
+
+Permission is hereby granted to use, copy, modify, and distribute this
+source code, or portions hereof, for any purpose, without fee, subject
+to the following restrictions:
+
+ 1. The origin of this source code must not be misrepresented.
+
+ 2. Altered versions must be plainly marked as such and must not
+ be misrepresented as being the original source.
+
+ 3. This Copyright notice may not be removed or altered from any
+ source or altered source distribution.
+
+The Contributing Authors and Group 42, Inc. specifically permit,
+without fee, and encourage the use of this source code as a component
+to supporting the PNG file format in commercial products. If you use
+this source code in a product, acknowledgment is not required but would
+be appreciated.
diff --git a/libs/imagequant/external/libpng/Makefile.am b/libs/imagequant/external/libpng/Makefile.am
new file mode 100644
index 00000000..44ab0ea0
--- /dev/null
+++ b/libs/imagequant/external/libpng/Makefile.am
@@ -0,0 +1,431 @@
+# Makefile.am, the source file for Makefile.in (and hence Makefile), is
+#
+# Copyright (c) 2018-2025 Cosmin Truta
+# Copyright (c) 2004-2016 Glenn Randers-Pehrson
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+PNGLIB_BASENAME= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@
+
+ACLOCAL_AMFLAGS = -I scripts/autoconf
+
+# test programs - run on make check, make distcheck
+if ENABLE_TESTS
+check_PROGRAMS= pngtest pngunknown pngstest pngvalid pngimage pngcp
+if HAVE_CLOCK_GETTIME
+check_PROGRAMS += timepng
+endif
+else
+check_PROGRAMS=
+endif
+
+# Utilities - installed
+if ENABLE_TOOLS
+bin_PROGRAMS= pngfix png-fix-itxt
+else
+bin_PROGRAMS=
+endif
+
+# This ensures that pnglibconf.h gets built at the start of 'make all' or
+# 'make check', but it does not add dependencies to the individual programs,
+# this is done below.
+#
+# IMPORTANT: always add the object modules of new programs to the list below
+# because otherwise the sequence 'configure; make new-program' will *sometimes*
+# result in the installed (system) pnglibconf.h being used and the result is
+# always wrong and always very confusing.
+BUILT_SOURCES = pnglibconf.h
+
+if ENABLE_TESTS
+pngtest_SOURCES = pngtest.c
+pngtest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+pngvalid_SOURCES = contrib/libtests/pngvalid.c
+pngvalid_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+pngstest_SOURCES = contrib/libtests/pngstest.c
+pngstest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+pngunknown_SOURCES = contrib/libtests/pngunknown.c
+pngunknown_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+pngimage_SOURCES = contrib/libtests/pngimage.c
+pngimage_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+timepng_SOURCES = contrib/libtests/timepng.c
+timepng_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+pngcp_SOURCES = contrib/tools/pngcp.c
+pngcp_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+endif
+
+if ENABLE_TOOLS
+pngfix_SOURCES = contrib/tools/pngfix.c
+pngfix_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+png_fix_itxt_SOURCES = contrib/tools/png-fix-itxt.c
+endif
+
+# Generally these are single line shell scripts to run a test with a particular
+# set of parameters:
+if ENABLE_TESTS
+TESTS =\
+ tests/pngtest-all\
+ tests/pngvalid-gamma-16-to-8 tests/pngvalid-gamma-alpha-mode\
+ tests/pngvalid-gamma-background tests/pngvalid-gamma-expand16-alpha-mode\
+ tests/pngvalid-gamma-expand16-background\
+ tests/pngvalid-gamma-expand16-transform tests/pngvalid-gamma-sbit\
+ tests/pngvalid-gamma-threshold tests/pngvalid-gamma-transform\
+ tests/pngvalid-progressive-size\
+ tests/pngvalid-progressive-interlace-standard\
+ tests/pngvalid-transform\
+ tests/pngvalid-progressive-standard tests/pngvalid-standard\
+ tests/pngstest-1.8 tests/pngstest-1.8-alpha tests/pngstest-linear\
+ tests/pngstest-linear-alpha tests/pngstest-none tests/pngstest-none-alpha\
+ tests/pngstest-sRGB tests/pngstest-sRGB-alpha tests/pngunknown-IDAT\
+ tests/pngunknown-discard tests/pngunknown-if-safe tests/pngunknown-sAPI\
+ tests/pngunknown-sTER tests/pngunknown-save tests/pngunknown-vpAg\
+ tests/pngimage-quick tests/pngimage-full
+endif
+
+# man pages
+dist_man_MANS= libpng.3 libpngpf.3 png.5
+
+# generate the -config scripts if required
+binconfigs= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@-config
+EXTRA_SCRIPTS= libpng-config libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@-config
+bin_SCRIPTS= @binconfigs@
+
+# rules to build libpng, only build the old library on request
+lib_LTLIBRARIES=libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+# EXTRA_LTLIBRARIES= libpng.la
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = png.c pngerror.c\
+ pngget.c pngmem.c pngpread.c pngread.c pngrio.c pngrtran.c pngrutil.c\
+ pngset.c pngtrans.c pngwio.c pngwrite.c pngwtran.c pngwutil.c\
+ png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h pngusr.dfa
+
+if PNG_ARM_NEON
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += arm/arm_init.c\
+ arm/filter_neon_intrinsics.c \
+ arm/palette_neon_intrinsics.c
+endif
+
+if PNG_MIPS_MSA
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += mips/mips_init.c\
+ mips/filter_msa_intrinsics.c
+endif
+
+if PNG_MIPS_MMI
+if !PNG_MIPS_MSA
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += mips/mips_init.c
+endif
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += mips/filter_mmi_inline_assembly.c
+endif
+
+if PNG_INTEL_SSE
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += intel/intel_init.c\
+ intel/filter_sse2_intrinsics.c
+endif
+
+if PNG_POWERPC_VSX
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += powerpc/powerpc_init.c\
+ powerpc/filter_vsx_intrinsics.c
+endif
+
+if PNG_RISCV_RVV
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += riscv/riscv_init.c\
+ riscv/filter_rvv_intrinsics.c
+endif
+
+if PNG_LOONGARCH_LSX
+noinst_LTLIBRARIES= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx.la
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_SOURCES = loongarch/loongarch_lsx_init.c\
+ loongarch/filter_lsx_intrinsics.c
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_CFLAGS = -mlsx
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LIBADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx.la
+# libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx.la
+endif
+
+nodist_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = pnglibconf.h
+
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LDFLAGS = -no-undefined -export-dynamic \
+ -version-number @PNGLIB_MAJOR@@PNGLIB_MINOR@:@PNGLIB_RELEASE@:0
+
+if HAVE_LD_VERSION_SCRIPT
+# Versioned symbols and restricted exports
+if HAVE_SOLARIS_LD
+ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LDFLAGS += -Wl,-M -Wl,libpng.vers
+else
+ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LDFLAGS += -Wl,--version-script=libpng.vers
+endif
+
+ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES = libpng.vers
+else
+# Only restricted exports when possible
+ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LDFLAGS += -export-symbols libpng.sym
+ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES = libpng.sym
+endif
+
+if PNG_LOONGARCH_LSX
+ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES += libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx.la
+endif
+
+#distribute headers in /usr/include/libpng/*
+pkgincludedir= $(includedir)/$(PNGLIB_BASENAME)
+pkginclude_HEADERS= png.h pngconf.h
+nodist_pkginclude_HEADERS= pnglibconf.h
+
+# pkg-config stuff, note that libpng.pc is always required in order
+# to get the correct library
+pkgconfigdir = @pkgconfigdir@
+pkgconfig_DATA = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.pc
+
+# Extra source distribution files, '${srcdir}' is used below to stop build files
+# from those directories being included. This only works if the configure is
+# not done in the source directory!
+EXTRA_DIST= \
+ ANNOUNCE AUTHORS CHANGES INSTALL LICENSE README TODO TRADEMARK \
+ pngtest.png pngbar.png pngnow.png pngbar.jpg autogen.sh \
+ ${srcdir}/ci ${srcdir}/contrib ${srcdir}/projects ${srcdir}/scripts \
+ $(TESTS) $(XFAIL_TESTS) tests/pngstest \
+ CMakeLists.txt example.c libpng-manual.txt
+
+SCRIPT_CLEANFILES=scripts/*.out scripts/*.chk
+
+CLEANFILES= *.tf? pngout.png libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.pc \
+ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@-config libpng.vers libpng.sym \
+ check.new pnglibconf.h pngprefix.h symbols.new pngtest-log.txt \
+ pnglibconf.out pnglibconf.c pnglibconf.pre pnglibconf.dfn \
+ $(SCRIPT_CLEANFILES)
+
+MAINTAINERCLEANFILES = Makefile.in aclocal.m4 config.guess config.h.in \
+config.sub configure depcomp install-sh ltmain.sh missing
+
+# PNG_COPTS give extra options for the C compiler to be used on all compilation
+# steps (unless target_CFLAGS is specified; that will take precedence over
+# AM_CFLAGS)
+PNG_COPTS = @PNG_COPTS@
+AM_CFLAGS = ${PNG_COPTS}
+
+# DFNCPP is normally just CPP - the C preprocessor - but on Solaris and maybe
+# other operating systems (NeXT?) the C preprocessor selected by configure
+# checks input tokens for validity - effectively it performs part of the ANSI-C
+# parsing - and therefore fails with the .df files. configure.ac has special
+# checks for this and sets DFNCPP appropriately.
+DFNCPP = @DFNCPP@
+
+SUFFIXES = .chk .out
+
+$(PNGLIB_BASENAME).pc: libpng.pc
+ cp libpng.pc $@
+
+$(PNGLIB_BASENAME)-config: libpng-config
+ cp libpng-config $@
+
+scripts/sym.out scripts/vers.out: png.h pngconf.h pnglibconf.h
+scripts/prefix.out: png.h pngconf.h pnglibconf.out
+scripts/symbols.out: png.h pngconf.h $(srcdir)/scripts/pnglibconf.h.prebuilt
+scripts/intprefix.out: pnglibconf.h
+
+libpng.sym: scripts/sym.out
+ rm -f $@
+ cp $? $@
+libpng.vers: scripts/vers.out
+ rm -f $@
+ cp $? $@
+
+if DO_PNG_PREFIX
+# Rename functions in scripts/prefix.out with a PNG_PREFIX prefix.
+# Rename macros in scripts/macro.lst from PNG_PREFIXpng_ to PNG_ (the actual
+# implementation of the macro).
+pnglibconf.h: pnglibconf.out scripts/prefix.out scripts/macro.lst
+ rm -f $@
+ $(AWK) 's==0 && NR>1{print prev}\
+ s==0{prev=$$0}\
+ s==1{print "#define", $$1, "@PNG_PREFIX@" $$1}\
+ s==2{print "#define @PNG_PREFIX@png_" $$1, "PNG_" $$1}\
+ END{print prev}' s=0 pnglibconf.out s=1 scripts/prefix.out\
+ s=2 ${srcdir}/scripts/macro.lst >pnglibconf.tf8
+ mv pnglibconf.tf8 $@
+
+pngprefix.h: scripts/intprefix.out
+ rm -f pngprefix.tf1
+ $(AWK) '{print "#define", $$1, "@PNG_PREFIX@" $$1}' $? >pngprefix.tf1
+ mv pngprefix.tf1 $@
+else
+pnglibconf.h: pnglibconf.out
+ rm -f $@
+ cp $? $@
+
+pngprefix.h: # is empty
+ :>$@
+endif
+
+$(srcdir)/scripts/pnglibconf.h.prebuilt:
+ @echo "Attempting to build $@" >&2
+ @echo "This is a machine generated file, but if you want to make" >&2
+ @echo "a new one simply make 'scripts/pnglibconf.out', copy that" >&2
+ @echo "AND set PNG_ZLIB_VERNUM to 0 (you MUST do this)" >&2
+ @exit 1
+
+# The following is necessary to ensure that the local pnglibconf.h is used, not
+# an installed one (this can happen immediately after on a clean system if
+# 'make test' is the first thing the user does.) Only files which include
+# one of the png source files (typically png.h or pngpriv.h) need to be listed
+# here:
+pngtest.o: pnglibconf.h
+
+contrib/libtests/makepng.o: pnglibconf.h
+contrib/libtests/pngstest.o: pnglibconf.h
+contrib/libtests/pngunknown.o: pnglibconf.h
+contrib/libtests/pngimage.o: pnglibconf.h
+contrib/libtests/pngvalid.o: pnglibconf.h
+contrib/libtests/readpng.o: pnglibconf.h
+contrib/libtests/tarith.o: pnglibconf.h
+contrib/libtests/timepng.o: pnglibconf.h
+
+contrib/tools/makesRGB.o: pnglibconf.h
+contrib/tools/pngfix.o: pnglibconf.h
+contrib/tools/pngcp.o: pnglibconf.h
+
+# We must use -DPNG_NO_USE_READ_MACROS here even when the library may actually
+# be built with PNG_USE_READ_MACROS; this prevents the read macros from
+# interfering with the symbol file format.
+SYMBOL_CFLAGS = -DPNGLIB_LIBNAME='PNG@PNGLIB_MAJOR@@PNGLIB_MINOR@_0'\
+ -DPNGLIB_VERSION='@PNGLIB_VERSION@'\
+ -DSYMBOL_PREFIX='$(SYMBOL_PREFIX)'\
+ -DPNG_NO_USE_READ_MACROS -DPNG_BUILDING_SYMBOL_TABLE
+
+if DO_PNG_PREFIX
+SYMBOL_CFLAGS += -DPNG_PREFIX='@PNG_PREFIX@'
+endif
+
+.c.out:
+ rm -f $@ $*.tf[12]
+ test -d scripts || mkdir scripts || test -d scripts
+ $(DFNCPP) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES)\
+ $(CPPFLAGS) $(SYMBOL_CFLAGS) $< > $*.tf1
+ $(AWK) -f "${srcdir}/scripts/dfn.awk" out="$*.tf2" $*.tf1 1>&2
+ rm -f $*.tf1
+ mv $*.tf2 $@
+
+# The .c file for pnglibconf.h is machine generated
+pnglibconf.c: scripts/pnglibconf.dfa scripts/options.awk pngconf.h pngusr.dfa $(DFA_XTRA)
+ rm -f $@ $*.tf[45]
+ $(AWK) -f ${srcdir}/scripts/options.awk out=$*.tf4 version=search\
+ ${srcdir}/pngconf.h ${srcdir}/scripts/pnglibconf.dfa\
+ ${srcdir}/pngusr.dfa $(DFA_XTRA) 1>&2
+ $(AWK) -f ${srcdir}/scripts/options.awk out=$*.tf5 $*.tf4 1>&2
+ rm $*.tf4
+ mv $*.tf5 $@
+
+# Symbol checks (.def and .out files should match)
+scripts/symbols.chk: scripts/checksym.awk scripts/symbols.def scripts/symbols.out
+
+.out.chk:
+ rm -f $@ $*.new
+ $(AWK) -f ${srcdir}/scripts/checksym.awk ${srcdir}/scripts/${*F}.def\
+ of="$*.new" $< >&2
+ mv $*.new $@
+
+# used on demand to regenerate the standard header, CPPFLAGS should
+# be empty - no non-standard defines
+scripts/pnglibconf.c: scripts/pnglibconf.dfa scripts/options.awk pngconf.h
+ rm -f $@ pnglibconf.tf[67]
+ test -z "$(CPPFLAGS)"
+ echo "com @PNGLIB_VERSION@ STANDARD API DEFINITION" |\
+ $(AWK) -f ${srcdir}/scripts/options.awk out=pnglibconf.tf6\
+ logunsupported=1 version=search ${srcdir}/pngconf.h -\
+ ${srcdir}/scripts/pnglibconf.dfa 1>&2
+ $(AWK) -f ${srcdir}/scripts/options.awk out=pnglibconf.tf7\
+ pnglibconf.tf6 1>&2
+ rm pnglibconf.tf6
+ mv pnglibconf.tf7 $@
+
+$(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_OBJECTS): png.h pngconf.h \
+ pnglibconf.h pngpriv.h pngdebug.h pnginfo.h pngstruct.h pngprefix.h
+
+test: check-am
+
+# Extra checks
+check: scripts/symbols.chk
+
+# Don't distribute the generated script files
+dist-hook:
+ cd '$(top_distdir)'; rm -f $(SCRIPT_CLEANFILES)
+
+# Make links between installed files with release-specific names and the generic
+# file names. If this install rule is run the generic names will be deleted and
+# recreated - this has obvious issues for systems with multiple installations.
+
+install-header-links:
+ @set -ex; cd '$(DESTDIR)$(includedir)'; for f in $(HEADERS); do \
+ rm -f "$$f"; $(LN_S) "$(PNGLIB_BASENAME)/$$f" "$$f"; done
+
+uninstall-header-links:
+ cd '$(DESTDIR)$(includedir)'; rm -f $(HEADERS)
+
+install-libpng-pc:
+ @set -ex; cd '$(DESTDIR)$(pkgconfigdir)'; rm -f libpng.pc; \
+ $(LN_S) '$(PNGLIB_BASENAME).pc' libpng.pc
+
+uninstall-libpng-pc:
+ rm -f '$(DESTDIR)$(pkgconfigdir)/libpng.pc'
+
+# EXT_LIST is a list of the possibly library directory extensions, this exists
+# because we can't find a good way of discovering the file extensions that are
+# actually installed on a given system, so instead we check for every extension
+# we have seen.
+
+EXT_LIST = a dll.a so so.@PNGLIB_MAJOR@@PNGLIB_MINOR@.@PNGLIB_RELEASE@ la sl dylib
+
+install-library-links:
+ @set -x; cd '$(DESTDIR)$(libdir)';\
+ for ext in $(EXT_LIST); do\
+ rm -f "libpng.$$ext";\
+ if test -f "$(PNGLIB_BASENAME).$$ext"; then\
+ $(LN_S) "$(PNGLIB_BASENAME).$$ext" "libpng.$$ext" || exit 1;\
+ fi;\
+ done
+
+uninstall-library-links:
+ @set -x; cd '$(DESTDIR)$(libdir)'; for ext in $(EXT_LIST); do\
+ rm -f "libpng.$$ext"; done
+
+install-libpng-config:
+ @set -ex; cd '$(DESTDIR)$(bindir)'; rm -f libpng-config; \
+ $(LN_S) '$(PNGLIB_BASENAME)-config' libpng-config
+
+uninstall-libpng-config:
+ rm -f '$(DESTDIR)$(bindir)/libpng-config'
+
+if DO_INSTALL_LINKS
+# If --enable-unversioned-links is specified the header and lib file links
+# will be automatically made on a 'make install':
+
+install-data-hook: install-header-links
+uninstall-hook: uninstall-header-links
+install-exec-hook: install-library-links
+uninstall-hook: uninstall-library-links
+endif
+
+if DO_INSTALL_LIBPNG_PC
+# Likewise, --install-pc causes libpng.pc to be constructed:
+
+install-data-hook: install-libpng-pc
+uninstall-hook: uninstall-libpng-pc
+endif
+
+if DO_INSTALL_LIBPNG_CONFIG
+# And --install-config:
+
+install-exec-hook: install-libpng-config
+uninstall-hook: uninstall-libpng-config
+endif
+
+# The following addition ensures that 'make all' always builds the test programs
+# too. It used to, but some change either in libpng or configure stopped this
+# working.
+all-am: $(check_PROGRAMS)
diff --git a/libs/imagequant/external/libpng/TRADEMARK b/libs/imagequant/external/libpng/TRADEMARK
new file mode 100644
index 00000000..ac667187
--- /dev/null
+++ b/libs/imagequant/external/libpng/TRADEMARK
@@ -0,0 +1,8 @@
+TRADEMARK
+=========
+
+The name "libpng" has not been registered by the Copyright owners
+as a trademark in any jurisdiction. However, because libpng has
+been distributed and maintained world-wide, continually since 1995,
+the Copyright owners claim "common-law trademark protection" in any
+jurisdiction where common-law trademark is recognized.
diff --git a/libs/imagequant/external/libpng/arm/arm_init.c b/libs/imagequant/external/libpng/arm/arm_init.c
new file mode 100644
index 00000000..0ea9c836
--- /dev/null
+++ b/libs/imagequant/external/libpng/arm/arm_init.c
@@ -0,0 +1,138 @@
+/* arm_init.c - NEON optimised filter functions
+ *
+ * Copyright (c) 2018-2022 Cosmin Truta
+ * Copyright (c) 2014,2016 Glenn Randers-Pehrson
+ * Written by Mans Rullgard, 2011.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+/* This module requires POSIX 1003.1 functions. */
+#define _POSIX_SOURCE 1
+
+#include "../pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+#if PNG_ARM_NEON_OPT > 0
+#ifdef PNG_ARM_NEON_CHECK_SUPPORTED /* Do run-time checks */
+/* WARNING: it is strongly recommended that you do not build libpng with
+ * run-time checks for CPU features if at all possible. In the case of the ARM
+ * NEON instructions there is no processor-specific way of detecting the
+ * presence of the required support, therefore run-time detection is extremely
+ * OS specific.
+ *
+ * You may set the macro PNG_ARM_NEON_FILE to the file name of file containing
+ * a fragment of C source code which defines the png_have_neon function. There
+ * are a number of implementations in contrib/arm-neon, but the only one that
+ * has partial support is contrib/arm-neon/linux.c - a generic Linux
+ * implementation which reads /proc/cpufino.
+ */
+#include /* for sig_atomic_t */
+
+#ifndef PNG_ARM_NEON_FILE
+# if defined(__aarch64__) || defined(_M_ARM64)
+ /* ARM Neon is expected to be unconditionally available on ARM64. */
+# error PNG_ARM_NEON_CHECK_SUPPORTED must not be defined on ARM64
+# elif defined(__ARM_NEON__) || defined(__ARM_NEON)
+ /* ARM Neon is expected to be available on the target CPU architecture. */
+# error PNG_ARM_NEON_CHECK_SUPPORTED must not be defined on this CPU arch
+# elif defined(__linux__)
+# define PNG_ARM_NEON_FILE "contrib/arm-neon/linux.c"
+# else
+# error No support for run-time ARM Neon checking; use compile-time options
+# endif
+#endif
+
+static int png_have_neon(png_structp png_ptr);
+#ifdef PNG_ARM_NEON_FILE
+# include PNG_ARM_NEON_FILE
+#endif
+#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */
+
+#ifndef PNG_ALIGNED_MEMORY_SUPPORTED
+# error ALIGNED_MEMORY is required; please define PNG_ALIGNED_MEMORY_SUPPORTED
+#endif
+
+void
+png_init_filter_functions_neon(png_structp pp, unsigned int bpp)
+{
+ /* The switch statement is compiled in for ARM_NEON_API, the call to
+ * png_have_neon is compiled in for ARM_NEON_CHECK. If both are defined
+ * the check is only performed if the API has not set the NEON option on
+ * or off explicitly. In this case the check controls what happens.
+ *
+ * If the CHECK is not compiled in and the option is UNSET the behavior prior
+ * to 1.6.7 was to use the NEON code - this was a bug caused by having the
+ * wrong order of the 'ON' and 'default' cases. UNSET now defaults to OFF,
+ * as documented in png.h
+ */
+ png_debug(1, "in png_init_filter_functions_neon");
+#ifdef PNG_ARM_NEON_API_SUPPORTED
+ switch ((pp->options >> PNG_ARM_NEON) & 3)
+ {
+ case PNG_OPTION_UNSET:
+ /* Allow the run-time check to execute if it has been enabled -
+ * thus both API and CHECK can be turned on. If it isn't supported
+ * this case will fall through to the 'default' below, which just
+ * returns.
+ */
+#endif /* PNG_ARM_NEON_API_SUPPORTED */
+#ifdef PNG_ARM_NEON_CHECK_SUPPORTED
+ {
+ static volatile sig_atomic_t no_neon = -1; /* not checked */
+
+ if (no_neon < 0)
+ no_neon = !png_have_neon(pp);
+
+ if (no_neon)
+ return;
+ }
+#ifdef PNG_ARM_NEON_API_SUPPORTED
+ break;
+#endif
+#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */
+
+#ifdef PNG_ARM_NEON_API_SUPPORTED
+ default: /* OFF or INVALID */
+ return;
+
+ case PNG_OPTION_ON:
+ /* Option turned on */
+ break;
+ }
+#endif
+
+ /* IMPORTANT: any new external functions used here must be declared using
+ * PNG_INTERNAL_FUNCTION in ../pngpriv.h. This is required so that the
+ * 'prefix' option to configure works:
+ *
+ * ./configure --with-libpng-prefix=foobar_
+ *
+ * Verify you have got this right by running the above command, doing a build
+ * and examining pngprefix.h; it must contain a #define for every external
+ * function you add. (Notice that this happens automatically for the
+ * initialization function.)
+ */
+ pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon;
+
+ if (bpp == 3)
+ {
+ pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon;
+ pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon;
+ pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+ png_read_filter_row_paeth3_neon;
+ }
+
+ else if (bpp == 4)
+ {
+ pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon;
+ pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon;
+ pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+ png_read_filter_row_paeth4_neon;
+ }
+}
+#endif /* PNG_ARM_NEON_OPT > 0 */
+#endif /* READ */
diff --git a/libs/imagequant/external/libpng/arm/filter_neon.S b/libs/imagequant/external/libpng/arm/filter_neon.S
new file mode 100644
index 00000000..0cbd372c
--- /dev/null
+++ b/libs/imagequant/external/libpng/arm/filter_neon.S
@@ -0,0 +1,60 @@
+/* filter_neon.S - placeholder file
+ *
+ * Copyright (c) 2024 Cosmin Truta
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+/* IMPORTANT NOTE:
+ *
+ * Historically, the hand-coded assembler implementation of Neon optimizations
+ * in this module had not been in sync with the intrinsics-based implementation
+ * in filter_neon_intrinsics.c and palette_neon_intrinsics.c, at least since
+ * the introduction of riffled palette optimizations. Moreover, the assembler
+ * code used to work on 32-bit ARM only, and it caused problems, even if empty,
+ * on 64-bit ARM.
+ *
+ * All references to this module from our internal build scripts and projects
+ * have been removed.
+ *
+ * For the external projects that might still expect this module to be present,
+ * we leave this stub in place, for the remaining lifetime of libpng-1.6.x.
+ * Everything should continue to function normally, as long as there are no
+ * deliberate attempts to use the old hand-made assembler code. A build error
+ * will be raised otherwise.
+ */
+
+/* This is required to get the symbol renames, which are #defines, and the
+ * definitions (or not) of PNG_ARM_NEON_OPT and PNG_ARM_NEON_IMPLEMENTATION.
+ */
+#define PNG_VERSION_INFO_ONLY
+#include "../pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+#if PNG_ARM_NEON_IMPLEMENTATION == 2 /* hand-coded assembler */
+#if PNG_ARM_NEON_OPT > 0
+
+#if defined(__clang__)
+#define GNUC_VERSION 0 /* not gcc, although it might pretend to be */
+#elif defined(__GNUC__)
+#define GNUC_MAJOR (__GNUC__ + 0)
+#define GNUC_MINOR (__GNUC_MINOR__ + 0)
+#define GNUC_PATCHLEVEL (__GNUC_PATCHLEVEL__ + 0)
+#define GNUC_VERSION (GNUC_MAJOR * 10000 + GNUC_MINOR * 100 + GNUC_PATCHLEVEL)
+#else
+#define GNUC_VERSION 0 /* not gcc */
+#endif
+
+#if (GNUC_VERSION > 0) && (GNUC_VERSION < 40300)
+#error "PNG_ARM_NEON is not supported with gcc versions earlier than 4.3.0"
+#elif GNUC_VERSION == 40504
+#error "PNG_ARM_NEON is not supported with gcc version 4.5.4"
+#else
+#error "Please use 'arm/*_neon_intrinsics.c' for PNG_ARM_NEON support"
+#endif
+
+#endif /* PNG_ARM_NEON_OPT > 0 */
+#endif /* PNG_ARM_NEON_IMPLEMENTATION == 2 */
+#endif /* READ */
diff --git a/libs/imagequant/external/libpng/arm/filter_neon_intrinsics.c b/libs/imagequant/external/libpng/arm/filter_neon_intrinsics.c
new file mode 100644
index 00000000..7c3e0da4
--- /dev/null
+++ b/libs/imagequant/external/libpng/arm/filter_neon_intrinsics.c
@@ -0,0 +1,401 @@
+/* filter_neon_intrinsics.c - NEON optimised filter functions
+ *
+ * Copyright (c) 2018 Cosmin Truta
+ * Copyright (c) 2014,2016 Glenn Randers-Pehrson
+ * Written by James Yu , October 2013.
+ * Based on filter_neon.S, written by Mans Rullgard, 2011.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "../pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+/* This code requires -mfpu=neon on the command line: */
+#if PNG_ARM_NEON_IMPLEMENTATION == 1 /* intrinsics code from pngpriv.h */
+
+#if defined(_MSC_VER) && !defined(__clang__) && defined(_M_ARM64)
+# include
+#else
+# include
+#endif
+
+/* libpng row pointers are not necessarily aligned to any particular boundary,
+ * however this code will only work with appropriate alignment. arm/arm_init.c
+ * checks for this (and will not compile unless it is done). This code uses
+ * variants of png_aligncast to avoid compiler warnings.
+ */
+#define png_ptr(type,pointer) png_aligncast(type *,pointer)
+#define png_ptrc(type,pointer) png_aligncastconst(const type *,pointer)
+
+/* The following relies on a variable 'temp_pointer' being declared with type
+ * 'type'. This is written this way just to hide the GCC strict aliasing
+ * warning; note that the code is safe because there never is an alias between
+ * the input and output pointers.
+ *
+ * When compiling with MSVC ARM64, the png_ldr macro can't be passed directly
+ * to vst4_lane_u32, because of an internal compiler error inside MSVC.
+ * To avoid this compiler bug, we use a temporary variable (vdest_val) to store
+ * the result of png_ldr.
+ */
+#define png_ldr(type,pointer)\
+ (temp_pointer = png_ptr(type,pointer), *temp_pointer)
+
+#if PNG_ARM_NEON_OPT > 0
+
+void
+png_read_filter_row_up_neon(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ png_bytep rp = row;
+ png_bytep rp_stop = row + row_info->rowbytes;
+ png_const_bytep pp = prev_row;
+
+ png_debug(1, "in png_read_filter_row_up_neon");
+
+ for (; rp < rp_stop; rp += 16, pp += 16)
+ {
+ uint8x16_t qrp, qpp;
+
+ qrp = vld1q_u8(rp);
+ qpp = vld1q_u8(pp);
+ qrp = vaddq_u8(qrp, qpp);
+ vst1q_u8(rp, qrp);
+ }
+}
+
+void
+png_read_filter_row_sub3_neon(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ png_bytep rp = row;
+ png_bytep rp_stop = row + row_info->rowbytes;
+
+ uint8x16_t vtmp = vld1q_u8(rp);
+ uint8x8x2_t *vrpt = png_ptr(uint8x8x2_t, &vtmp);
+ uint8x8x2_t vrp = *vrpt;
+
+ uint8x8x4_t vdest;
+ vdest.val[3] = vdup_n_u8(0);
+
+ png_debug(1, "in png_read_filter_row_sub3_neon");
+
+ for (; rp < rp_stop;)
+ {
+ uint8x8_t vtmp1, vtmp2;
+ uint32x2_t *temp_pointer;
+
+ vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3);
+ vdest.val[0] = vadd_u8(vdest.val[3], vrp.val[0]);
+ vtmp2 = vext_u8(vrp.val[0], vrp.val[1], 6);
+ vdest.val[1] = vadd_u8(vdest.val[0], vtmp1);
+
+ vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1);
+ vdest.val[2] = vadd_u8(vdest.val[1], vtmp2);
+ vdest.val[3] = vadd_u8(vdest.val[2], vtmp1);
+
+ vtmp = vld1q_u8(rp + 12);
+ vrpt = png_ptr(uint8x8x2_t, &vtmp);
+ vrp = *vrpt;
+
+ vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0);
+ rp += 3;
+ vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0);
+ rp += 3;
+ vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0);
+ rp += 3;
+ vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0);
+ rp += 3;
+ }
+
+ PNG_UNUSED(prev_row)
+}
+
+void
+png_read_filter_row_sub4_neon(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ png_bytep rp = row;
+ png_bytep rp_stop = row + row_info->rowbytes;
+
+ uint8x8x4_t vdest;
+ vdest.val[3] = vdup_n_u8(0);
+
+ png_debug(1, "in png_read_filter_row_sub4_neon");
+
+ for (; rp < rp_stop; rp += 16)
+ {
+ uint32x2x4_t vtmp = vld4_u32(png_ptr(uint32_t,rp));
+ uint8x8x4_t *vrpt = png_ptr(uint8x8x4_t,&vtmp);
+ uint8x8x4_t vrp = *vrpt;
+ uint32x2x4_t *temp_pointer;
+ uint32x2x4_t vdest_val;
+
+ vdest.val[0] = vadd_u8(vdest.val[3], vrp.val[0]);
+ vdest.val[1] = vadd_u8(vdest.val[0], vrp.val[1]);
+ vdest.val[2] = vadd_u8(vdest.val[1], vrp.val[2]);
+ vdest.val[3] = vadd_u8(vdest.val[2], vrp.val[3]);
+
+ vdest_val = png_ldr(uint32x2x4_t, &vdest);
+ vst4_lane_u32(png_ptr(uint32_t,rp), vdest_val, 0);
+ }
+
+ PNG_UNUSED(prev_row)
+}
+
+void
+png_read_filter_row_avg3_neon(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ png_bytep rp = row;
+ png_const_bytep pp = prev_row;
+ png_bytep rp_stop = row + row_info->rowbytes;
+
+ uint8x16_t vtmp;
+ uint8x8x2_t *vrpt;
+ uint8x8x2_t vrp;
+ uint8x8x4_t vdest;
+ vdest.val[3] = vdup_n_u8(0);
+
+ vtmp = vld1q_u8(rp);
+ vrpt = png_ptr(uint8x8x2_t,&vtmp);
+ vrp = *vrpt;
+
+ png_debug(1, "in png_read_filter_row_avg3_neon");
+
+ for (; rp < rp_stop; pp += 12)
+ {
+ uint8x8_t vtmp1, vtmp2, vtmp3;
+
+ uint8x8x2_t *vppt;
+ uint8x8x2_t vpp;
+
+ uint32x2_t *temp_pointer;
+
+ vtmp = vld1q_u8(pp);
+ vppt = png_ptr(uint8x8x2_t,&vtmp);
+ vpp = *vppt;
+
+ vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3);
+ vdest.val[0] = vhadd_u8(vdest.val[3], vpp.val[0]);
+ vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+
+ vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 3);
+ vtmp3 = vext_u8(vrp.val[0], vrp.val[1], 6);
+ vdest.val[1] = vhadd_u8(vdest.val[0], vtmp2);
+ vdest.val[1] = vadd_u8(vdest.val[1], vtmp1);
+
+ vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 6);
+ vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1);
+
+ vtmp = vld1q_u8(rp + 12);
+ vrpt = png_ptr(uint8x8x2_t,&vtmp);
+ vrp = *vrpt;
+
+ vdest.val[2] = vhadd_u8(vdest.val[1], vtmp2);
+ vdest.val[2] = vadd_u8(vdest.val[2], vtmp3);
+
+ vtmp2 = vext_u8(vpp.val[1], vpp.val[1], 1);
+
+ vdest.val[3] = vhadd_u8(vdest.val[2], vtmp2);
+ vdest.val[3] = vadd_u8(vdest.val[3], vtmp1);
+
+ vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0);
+ rp += 3;
+ vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0);
+ rp += 3;
+ vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0);
+ rp += 3;
+ vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0);
+ rp += 3;
+ }
+}
+
+void
+png_read_filter_row_avg4_neon(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ png_bytep rp = row;
+ png_bytep rp_stop = row + row_info->rowbytes;
+ png_const_bytep pp = prev_row;
+
+ uint8x8x4_t vdest;
+ vdest.val[3] = vdup_n_u8(0);
+
+ png_debug(1, "in png_read_filter_row_avg4_neon");
+
+ for (; rp < rp_stop; rp += 16, pp += 16)
+ {
+ uint32x2x4_t vtmp;
+ uint8x8x4_t *vrpt, *vppt;
+ uint8x8x4_t vrp, vpp;
+ uint32x2x4_t *temp_pointer;
+ uint32x2x4_t vdest_val;
+
+ vtmp = vld4_u32(png_ptr(uint32_t,rp));
+ vrpt = png_ptr(uint8x8x4_t,&vtmp);
+ vrp = *vrpt;
+ vtmp = vld4_u32(png_ptrc(uint32_t,pp));
+ vppt = png_ptr(uint8x8x4_t,&vtmp);
+ vpp = *vppt;
+
+ vdest.val[0] = vhadd_u8(vdest.val[3], vpp.val[0]);
+ vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+ vdest.val[1] = vhadd_u8(vdest.val[0], vpp.val[1]);
+ vdest.val[1] = vadd_u8(vdest.val[1], vrp.val[1]);
+ vdest.val[2] = vhadd_u8(vdest.val[1], vpp.val[2]);
+ vdest.val[2] = vadd_u8(vdest.val[2], vrp.val[2]);
+ vdest.val[3] = vhadd_u8(vdest.val[2], vpp.val[3]);
+ vdest.val[3] = vadd_u8(vdest.val[3], vrp.val[3]);
+
+ vdest_val = png_ldr(uint32x2x4_t, &vdest);
+ vst4_lane_u32(png_ptr(uint32_t,rp), vdest_val, 0);
+ }
+}
+
+static uint8x8_t
+paeth(uint8x8_t a, uint8x8_t b, uint8x8_t c)
+{
+ uint8x8_t d, e;
+ uint16x8_t p1, pa, pb, pc;
+
+ p1 = vaddl_u8(a, b); /* a + b */
+ pc = vaddl_u8(c, c); /* c * 2 */
+ pa = vabdl_u8(b, c); /* pa */
+ pb = vabdl_u8(a, c); /* pb */
+ pc = vabdq_u16(p1, pc); /* pc */
+
+ p1 = vcleq_u16(pa, pb); /* pa <= pb */
+ pa = vcleq_u16(pa, pc); /* pa <= pc */
+ pb = vcleq_u16(pb, pc); /* pb <= pc */
+
+ p1 = vandq_u16(p1, pa); /* pa <= pb && pa <= pc */
+
+ d = vmovn_u16(pb);
+ e = vmovn_u16(p1);
+
+ d = vbsl_u8(d, b, c);
+ e = vbsl_u8(e, a, d);
+
+ return e;
+}
+
+void
+png_read_filter_row_paeth3_neon(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ png_bytep rp = row;
+ png_const_bytep pp = prev_row;
+ png_bytep rp_stop = row + row_info->rowbytes;
+
+ uint8x16_t vtmp;
+ uint8x8x2_t *vrpt;
+ uint8x8x2_t vrp;
+ uint8x8_t vlast = vdup_n_u8(0);
+ uint8x8x4_t vdest;
+ vdest.val[3] = vdup_n_u8(0);
+
+ vtmp = vld1q_u8(rp);
+ vrpt = png_ptr(uint8x8x2_t,&vtmp);
+ vrp = *vrpt;
+
+ png_debug(1, "in png_read_filter_row_paeth3_neon");
+
+ for (; rp < rp_stop; pp += 12)
+ {
+ uint8x8x2_t *vppt;
+ uint8x8x2_t vpp;
+ uint8x8_t vtmp1, vtmp2, vtmp3;
+ uint32x2_t *temp_pointer;
+
+ vtmp = vld1q_u8(pp);
+ vppt = png_ptr(uint8x8x2_t,&vtmp);
+ vpp = *vppt;
+
+ vdest.val[0] = paeth(vdest.val[3], vpp.val[0], vlast);
+ vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+
+ vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3);
+ vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 3);
+ vdest.val[1] = paeth(vdest.val[0], vtmp2, vpp.val[0]);
+ vdest.val[1] = vadd_u8(vdest.val[1], vtmp1);
+
+ vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 6);
+ vtmp3 = vext_u8(vpp.val[0], vpp.val[1], 6);
+ vdest.val[2] = paeth(vdest.val[1], vtmp3, vtmp2);
+ vdest.val[2] = vadd_u8(vdest.val[2], vtmp1);
+
+ vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1);
+ vtmp2 = vext_u8(vpp.val[1], vpp.val[1], 1);
+
+ vtmp = vld1q_u8(rp + 12);
+ vrpt = png_ptr(uint8x8x2_t,&vtmp);
+ vrp = *vrpt;
+
+ vdest.val[3] = paeth(vdest.val[2], vtmp2, vtmp3);
+ vdest.val[3] = vadd_u8(vdest.val[3], vtmp1);
+
+ vlast = vtmp2;
+
+ vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0);
+ rp += 3;
+ vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0);
+ rp += 3;
+ vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0);
+ rp += 3;
+ vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0);
+ rp += 3;
+ }
+}
+
+void
+png_read_filter_row_paeth4_neon(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ png_bytep rp = row;
+ png_bytep rp_stop = row + row_info->rowbytes;
+ png_const_bytep pp = prev_row;
+
+ uint8x8_t vlast = vdup_n_u8(0);
+ uint8x8x4_t vdest;
+ vdest.val[3] = vdup_n_u8(0);
+
+ png_debug(1, "in png_read_filter_row_paeth4_neon");
+
+ for (; rp < rp_stop; rp += 16, pp += 16)
+ {
+ uint32x2x4_t vtmp;
+ uint8x8x4_t *vrpt, *vppt;
+ uint8x8x4_t vrp, vpp;
+ uint32x2x4_t *temp_pointer;
+ uint32x2x4_t vdest_val;
+
+ vtmp = vld4_u32(png_ptr(uint32_t,rp));
+ vrpt = png_ptr(uint8x8x4_t,&vtmp);
+ vrp = *vrpt;
+ vtmp = vld4_u32(png_ptrc(uint32_t,pp));
+ vppt = png_ptr(uint8x8x4_t,&vtmp);
+ vpp = *vppt;
+
+ vdest.val[0] = paeth(vdest.val[3], vpp.val[0], vlast);
+ vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+ vdest.val[1] = paeth(vdest.val[0], vpp.val[1], vpp.val[0]);
+ vdest.val[1] = vadd_u8(vdest.val[1], vrp.val[1]);
+ vdest.val[2] = paeth(vdest.val[1], vpp.val[2], vpp.val[1]);
+ vdest.val[2] = vadd_u8(vdest.val[2], vrp.val[2]);
+ vdest.val[3] = paeth(vdest.val[2], vpp.val[3], vpp.val[2]);
+ vdest.val[3] = vadd_u8(vdest.val[3], vrp.val[3]);
+
+ vlast = vpp.val[3];
+
+ vdest_val = png_ldr(uint32x2x4_t, &vdest);
+ vst4_lane_u32(png_ptr(uint32_t,rp), vdest_val, 0);
+ }
+}
+
+#endif /* PNG_ARM_NEON_OPT > 0 */
+#endif /* PNG_ARM_NEON_IMPLEMENTATION == 1 (intrinsics) */
+#endif /* READ */
diff --git a/libs/imagequant/external/libpng/arm/palette_neon_intrinsics.c b/libs/imagequant/external/libpng/arm/palette_neon_intrinsics.c
new file mode 100644
index 00000000..3068e9b6
--- /dev/null
+++ b/libs/imagequant/external/libpng/arm/palette_neon_intrinsics.c
@@ -0,0 +1,150 @@
+/* palette_neon_intrinsics.c - NEON optimised palette expansion functions
+ *
+ * Copyright (c) 2018-2019 Cosmin Truta
+ * Copyright (c) 2017-2018 Arm Holdings. All rights reserved.
+ * Written by Richard Townsend , February 2017.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "../pngpriv.h"
+
+#if PNG_ARM_NEON_IMPLEMENTATION == 1
+
+#if defined(_MSC_VER) && !defined(__clang__) && defined(_M_ARM64)
+# include
+#else
+# include
+#endif
+
+/* Build an RGBA8 palette from the separate RGB and alpha palettes. */
+void
+png_riffle_palette_neon(png_structrp png_ptr)
+{
+ png_const_colorp palette = png_ptr->palette;
+ png_bytep riffled_palette = png_ptr->riffled_palette;
+ png_const_bytep trans_alpha = png_ptr->trans_alpha;
+ int num_trans = png_ptr->num_trans;
+ int i;
+
+ /* Initially black, opaque. */
+ uint8x16x4_t w = {{
+ vdupq_n_u8(0x00),
+ vdupq_n_u8(0x00),
+ vdupq_n_u8(0x00),
+ vdupq_n_u8(0xff),
+ }};
+
+ png_debug(1, "in png_riffle_palette_neon");
+
+ /* First, riffle the RGB colours into an RGBA8 palette.
+ * The alpha component is set to opaque for now.
+ */
+ for (i = 0; i < 256; i += 16)
+ {
+ uint8x16x3_t v = vld3q_u8((png_const_bytep)(palette + i));
+ w.val[0] = v.val[0];
+ w.val[1] = v.val[1];
+ w.val[2] = v.val[2];
+ vst4q_u8(riffled_palette + (i << 2), w);
+ }
+
+ /* Fix up the missing transparency values. */
+ for (i = 0; i < num_trans; i++)
+ riffled_palette[(i << 2) + 3] = trans_alpha[i];
+}
+
+/* Expands a palettized row into RGBA8. */
+int
+png_do_expand_palette_rgba8_neon(png_structrp png_ptr, png_row_infop row_info,
+ png_const_bytep row, png_bytepp ssp, png_bytepp ddp)
+{
+ png_uint_32 row_width = row_info->width;
+ const png_uint_32 *riffled_palette =
+ png_aligncastconst(png_const_uint_32p, png_ptr->riffled_palette);
+ const png_uint_32 pixels_per_chunk = 4;
+ png_uint_32 i;
+
+ png_debug(1, "in png_do_expand_palette_rgba8_neon");
+
+ PNG_UNUSED(row)
+ if (row_width < pixels_per_chunk)
+ return 0;
+
+ /* This function originally gets the last byte of the output row.
+ * The NEON part writes forward from a given position, so we have
+ * to seek this back by 4 pixels x 4 bytes.
+ */
+ *ddp = *ddp - ((pixels_per_chunk * sizeof(png_uint_32)) - 1);
+
+ for (i = 0; i < row_width; i += pixels_per_chunk)
+ {
+ uint32x4_t cur;
+ png_bytep sp = *ssp - i, dp = *ddp - (i << 2);
+ cur = vld1q_dup_u32 (riffled_palette + *(sp - 3));
+ cur = vld1q_lane_u32(riffled_palette + *(sp - 2), cur, 1);
+ cur = vld1q_lane_u32(riffled_palette + *(sp - 1), cur, 2);
+ cur = vld1q_lane_u32(riffled_palette + *(sp - 0), cur, 3);
+ vst1q_u32((void *)dp, cur);
+ }
+ if (i != row_width)
+ {
+ /* Remove the amount that wasn't processed. */
+ i -= pixels_per_chunk;
+ }
+
+ /* Decrement output pointers. */
+ *ssp = *ssp - i;
+ *ddp = *ddp - (i << 2);
+ return i;
+}
+
+/* Expands a palettized row into RGB8. */
+int
+png_do_expand_palette_rgb8_neon(png_structrp png_ptr, png_row_infop row_info,
+ png_const_bytep row, png_bytepp ssp, png_bytepp ddp)
+{
+ png_uint_32 row_width = row_info->width;
+ png_const_bytep palette = (png_const_bytep)png_ptr->palette;
+ const png_uint_32 pixels_per_chunk = 8;
+ png_uint_32 i;
+
+ png_debug(1, "in png_do_expand_palette_rgb8_neon");
+
+ PNG_UNUSED(row)
+ if (row_width <= pixels_per_chunk)
+ return 0;
+
+ /* Seeking this back by 8 pixels x 3 bytes. */
+ *ddp = *ddp - ((pixels_per_chunk * sizeof(png_color)) - 1);
+
+ for (i = 0; i < row_width; i += pixels_per_chunk)
+ {
+ uint8x8x3_t cur;
+ png_bytep sp = *ssp - i, dp = *ddp - ((i << 1) + i);
+ cur = vld3_dup_u8(palette + sizeof(png_color) * (*(sp - 7)));
+ cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 6)), cur, 1);
+ cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 5)), cur, 2);
+ cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 4)), cur, 3);
+ cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 3)), cur, 4);
+ cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 2)), cur, 5);
+ cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 1)), cur, 6);
+ cur = vld3_lane_u8(palette + sizeof(png_color) * (*(sp - 0)), cur, 7);
+ vst3_u8((void *)dp, cur);
+ }
+
+ if (i != row_width)
+ {
+ /* Remove the amount that wasn't processed. */
+ i -= pixels_per_chunk;
+ }
+
+ /* Decrement output pointers. */
+ *ssp = *ssp - i;
+ *ddp = *ddp - ((i << 1) + i);
+ return i;
+}
+
+#endif /* PNG_ARM_NEON_IMPLEMENTATION */
diff --git a/libs/imagequant/external/libpng/configure.ac b/libs/imagequant/external/libpng/configure.ac
new file mode 100644
index 00000000..348a2904
--- /dev/null
+++ b/libs/imagequant/external/libpng/configure.ac
@@ -0,0 +1,725 @@
+# configure.ac
+
+# Copyright (c) 2018-2024 Cosmin Truta
+# Copyright (c) 2004-2016 Glenn Randers-Pehrson
+
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+dnl Process this file with autoconf to produce a configure script.
+dnl
+dnl Minor upgrades (compatible ABI): increment the package version
+dnl (third field in two places below) and set the PNGLIB_RELEASE
+dnl variable.
+dnl
+dnl Major upgrades (incompatible ABI): increment the package major
+dnl version (second field, or first if desired), set the minor
+dnl to 0, set PNGLIB_MAJOR below *and* follow the instructions in
+dnl Makefile.am to upgrade the package name.
+
+dnl This is here to prevent earlier autoconf from being used, it
+dnl should not be necessary to regenerate configure if the time
+dnl stamps are correct
+AC_PREREQ([2.68])
+
+dnl Version number stuff here:
+
+AC_INIT([libpng],[1.6.49.git],[png-mng-implement@lists.sourceforge.net])
+AC_CONFIG_MACRO_DIR([scripts/autoconf])
+
+# libpng does not follow GNU file name conventions (hence 'foreign')
+# color-tests requires automake 1.11 or later
+# silent-rules requires automake 1.11 or later
+# dist-xz requires automake 1.11 or later
+# 1.12.2 fixes a security issue in 1.11.2 and 1.12.1
+# 1.13 is required for parallel tests
+AM_INIT_AUTOMAKE([1.13 foreign dist-xz color-tests silent-rules subdir-objects])
+# The following line causes --disable-maintainer-mode to be the default to
+# configure. This is necessary because libpng distributions cannot rely on the
+# time stamps of the autotools generated files being correct
+AM_MAINTAINER_MODE
+
+dnl configure.ac and Makefile.am expect automake 1.11.2 or a compatible later
+dnl version; aclocal.m4 will generate a failure if you use a prior version of
+dnl automake, so the following is not necessary (and is not defined anyway):
+dnl AM_PREREQ([1.11.2])
+dnl stop configure from automagically running automake
+
+PNGLIB_VERSION=1.6.49.git
+PNGLIB_MAJOR=1
+PNGLIB_MINOR=6
+PNGLIB_RELEASE=49
+
+dnl End of version number stuff
+
+AC_CONFIG_SRCDIR([pngget.c])
+AC_CONFIG_HEADERS([config.h])
+
+# Check the basic programs.
+AC_LANG([C])
+AC_PROG_CC
+AM_PROG_AS
+LT_PATH_LD
+AC_PROG_CPP
+AC_PROG_AWK
+AC_PROG_INSTALL
+AC_PROG_LN_S
+AC_PROG_MAKE_SET
+
+dnl libtool/libtoolize; version 2.4.2 is the tested version. This or any
+dnl compatible later version may be used
+LT_INIT([win32-dll])
+LT_PREREQ([2.4.2])
+
+dnl Declare the AWK variable.
+AC_ARG_VAR(AWK, [AWK language processor])
+
+# Some awk implementations crash when confronted with pnglibconf.dfa.
+# Run a test now, to make sure this doesn't happen.
+AC_MSG_CHECKING([if awk ($AWK) works])
+if ${AWK} -f ${srcdir}/scripts/options.awk out="/dev/null" version=search\
+ ${srcdir}/pngconf.h ${srcdir}/scripts/pnglibconf.dfa\
+ ${srcdir}/pngusr.dfa 1>&2
+then
+ AC_MSG_RESULT([yes])
+else
+ AC_MSG_FAILURE([no], 1)
+fi
+
+# This is a remnant of the old cc -E validation, where it may have been
+# necessary to use a different preprocessor for .dfn files
+DFNCPP="$CPP"
+AC_SUBST(DFNCPP)
+
+AC_ARG_ENABLE([tests],
+ AS_HELP_STRING([--disable-tests],
+ [do not build the test programs (default is to build)]),
+ [enable_tests="$enableval"],
+ [enable_tests=yes])
+
+AM_CONDITIONAL([ENABLE_TESTS],
+ [test "$enable_tests" != "no"])
+
+AC_ARG_ENABLE([tools],
+ AS_HELP_STRING([--disable-tools],
+ [do not build the auxiliary tools (default is to build)]),
+ [enable_tools="$enableval"],
+ [enable_tools=yes])
+
+AM_CONDITIONAL([ENABLE_TOOLS],
+ [test "$enable_tools" != "no"])
+
+# -Werror cannot be passed to GCC in CFLAGS because configure will fail
+# (it checks the compiler with a program that generates a warning).
+# Add the following option to deal with this:
+AC_ARG_VAR(PNG_COPTS,
+ [additional flags for the C compiler, to be used for options that would]
+ [cause configure itself to fail])
+AC_ARG_ENABLE(werror,
+ AS_HELP_STRING([[[--enable-werror[=OPT]]]],
+ [Pass -Werror or the given argument to the compiler if it is supported]),
+ [test "$enable_werror" = "yes" && enable_werror="-Werror"
+ if test "$enable_werror" != "no"; then
+ sav_CFLAGS="$CFLAGS"
+ CFLAGS="$enable_werror $CFLAGS"
+ AC_MSG_CHECKING([if the compiler allows $enable_werror])
+ AC_COMPILE_IFELSE(
+ [AC_LANG_SOURCE([
+ [int main(int argc, char **argv){]
+ [return argv[argc-1][0];]
+ [}]])],
+ AC_MSG_RESULT(yes)
+ PNG_COPTS="$PNG_COPTS $enable_werror",
+ AC_MSG_RESULT(no))
+ CFLAGS="$sav_CFLAGS"
+ fi],)
+
+# For GCC 5 the default mode for C is -std=gnu11 instead of -std=gnu89.
+# In pngpriv.h we request just the POSIX 1003.1 and C89 APIs by defining
+# _POSIX_SOURCE to 1. This is incompatible with the new default mode, so
+# we test for that and force the "-std=c89" compiler option:
+AC_MSG_CHECKING([if we need to force back C standard to C89])
+AC_COMPILE_IFELSE(
+ [AC_LANG_PROGRAM([
+ [#define _POSIX_SOURCE 1]
+ [#include ]
+ ])],
+ AC_MSG_RESULT(no),[
+ if test "x$GCC" != "xyes"; then
+ AC_MSG_ERROR(
+ [Forcing back to C89 is required but the flags are only known for GCC])
+ fi
+ AC_MSG_RESULT(yes)
+ CFLAGS="$CFLAGS -std=c89"
+])
+
+# Checks for structures and compiler characteristics.
+AC_STRUCT_TM
+AC_C_RESTRICT
+
+# Checks for library functions.
+AC_CHECK_FUNCS([pow], ,
+ [AC_CHECK_LIB([m], [pow], , [AC_MSG_ERROR([cannot find pow])])])
+
+# Some later POSIX 1003.1 functions are required for test programs, failure
+# here is soft (the corresponding test program is not built).
+AC_CHECK_FUNC([clock_gettime], , [AC_MSG_WARN([not building timepng])])
+AM_CONDITIONAL([HAVE_CLOCK_GETTIME], [test "$ac_cv_func_clock_gettime" = "yes"])
+
+AC_ARG_WITH(zlib-prefix,
+ AS_HELP_STRING([[[--with-zlib-prefix]]],
+ [prefix that may have been used in installed zlib]),
+ [ZPREFIX=${withval}],
+ [ZPREFIX='z_'])
+AC_CHECK_LIB([z], [zlibVersion], ,
+ [AC_CHECK_LIB([z], [${ZPREFIX}zlibVersion], ,
+ [AC_MSG_ERROR([zlib not installed])])])
+
+# The following is for pngvalid, to ensure it catches FP errors even on
+# platforms that don't enable FP exceptions, the function appears in the math
+# library (typically), it's not an error if it is not found.
+AC_CHECK_LIB([m], [feenableexcept])
+AC_CHECK_FUNCS([feenableexcept])
+
+AC_MSG_CHECKING([if using Solaris linker])
+SLD=`$LD --version 2>&1 | grep Solaris`
+if test "$SLD"; then
+ have_solaris_ld=yes
+ AC_MSG_RESULT(yes)
+else
+ have_solaris_ld=no
+ AC_MSG_RESULT(no)
+fi
+AM_CONDITIONAL(HAVE_SOLARIS_LD, test "$have_solaris_ld" = "yes")
+
+AC_MSG_CHECKING([if libraries can be versioned])
+# Special case for PE/COFF platforms: ld reports
+# support for version-script, but doesn't actually
+# DO anything with it.
+case $host in
+*cygwin* | *mingw32* | *interix* )
+ have_ld_version_script=no
+ AC_MSG_RESULT(no)
+;;
+* )
+
+if test "$have_solaris_ld" = "yes"; then
+ GLD=`$LD --help < /dev/null 2>&1 | grep 'M mapfile'`
+else
+ GLD=`$LD --help < /dev/null 2>/dev/null | grep version-script`
+fi
+
+if test "$GLD"; then
+ have_ld_version_script=yes
+ AC_MSG_RESULT(yes)
+else
+ have_ld_version_script=no
+ AC_MSG_RESULT(no)
+ AC_MSG_WARN(*** You have not enabled versioned symbols.)
+fi
+;;
+esac
+
+AM_CONDITIONAL(HAVE_LD_VERSION_SCRIPT, test "$have_ld_version_script" = "yes")
+
+if test "$have_ld_version_script" = "yes"; then
+ AC_MSG_CHECKING([for symbol prefix])
+ SYMBOL_PREFIX=`echo "PREFIX=__USER_LABEL_PREFIX__" \
+ | ${CPP:-${CC:-gcc} -E} - 2>&1 \
+ | ${EGREP:-grep} "^PREFIX=" \
+ | ${SED:-sed} -e "s:^PREFIX=::" -e "s:__USER_LABEL_PREFIX__::"`
+ AC_SUBST(SYMBOL_PREFIX)
+ AC_MSG_RESULT($SYMBOL_PREFIX)
+fi
+
+# Substitutions for .in files
+AC_SUBST(PNGLIB_VERSION)
+AC_SUBST(PNGLIB_MAJOR)
+AC_SUBST(PNGLIB_MINOR)
+AC_SUBST(PNGLIB_RELEASE)
+
+# Additional arguments (and substitutions)
+# Allow the pkg-config directory to be set
+AC_ARG_WITH(pkgconfigdir,
+ AS_HELP_STRING([[[--with-pkgconfigdir]]],
+ [Use the specified pkgconfig dir (default is libdir/pkgconfig)]),
+ [pkgconfigdir=${withval}],
+ [pkgconfigdir='${libdir}/pkgconfig'])
+
+AC_SUBST([pkgconfigdir])
+AC_MSG_NOTICE([[pkgconfig directory is ${pkgconfigdir}]])
+
+# Make the *-config binary config scripts optional
+AC_ARG_WITH(binconfigs,
+ AS_HELP_STRING([[[--with-binconfigs]]],
+ [Generate shell libpng-config scripts as well as pkg-config data]
+ [@<:@default=yes@:>@]),
+ [if test "${withval}" = no; then
+ binconfigs=
+ AC_MSG_NOTICE([[libpng-config scripts will not be built]])
+ else
+ binconfigs='${binconfigs}'
+ fi],
+ [binconfigs='${binconfigs}'])
+AC_SUBST([binconfigs])
+
+# Support for prefixes to the API function names; this will generate defines
+# at the start of the build to rename exported library functions
+AC_ARG_WITH(libpng-prefix,
+ AS_HELP_STRING([[[--with-libpng-prefix]]],
+ [prefix libpng exported function (API) names with the given value]),
+ [if test "${withval:-no}" != "no"; then
+ AC_SUBST([PNG_PREFIX], [${withval}])
+ fi])
+AM_CONDITIONAL([DO_PNG_PREFIX], [test "${with_libpng_prefix:-no}" != "no"])
+
+# Control over what links are made for installed files. Versioned files are
+# always installed, when the following options are turned on corresponding
+# unversioned links are also created (normally as symbolic links):
+AC_ARG_ENABLE([unversioned-links],
+ AS_HELP_STRING([[[--enable-unversioned-links]]],
+ [Installed libpng header files are placed in a versioned subdirectory]
+ [and installed libpng library (including DLL) files are versioned.]
+ [If this option is enabled unversioned links will be created pointing to]
+ [the corresponding installed files. If you use libpng.pc or]
+ [libpng-config for all builds you do not need these links, but if you]
+ [compile programs directly they will typically #include and]
+ [link with -lpng; in that case you need the links.]
+ [The links can be installed manually using 'make install-header-links']
+ [and 'make install-library-links' and can be removed using the]
+ [corresponding uninstall- targets. If you do enable this option every]
+ [libpng 'make install' will recreate the links to point to the just]
+ [installed version of libpng. The default is to create the links;]
+ [use --disable-unversioned-links to change this]))
+
+# The AM_CONDITIONAL test is written so that the default is enabled;
+# --disable-unversioned-links must be given to turn the option off.
+AM_CONDITIONAL([DO_INSTALL_LINKS],[test "$enable_unversioned_links" != "no"])
+
+AC_ARG_ENABLE([unversioned-libpng-pc],
+ AS_HELP_STRING([[[--enable-unversioned-libpng-pc]]],
+ [Install the configuration file 'libpng.pc' as a link to the versioned]
+ [version. This is done by default - use --disable-unversioned-libpng-pc]
+ [to change this.]))
+AM_CONDITIONAL([DO_INSTALL_LIBPNG_PC],
+ [test "$enable_unversioned_libpng_pc" != "no"])
+
+AC_ARG_ENABLE([unversioned-libpng-config],
+ AS_HELP_STRING([[[--enable-unversioned-libpng-config]]],
+ [Install the configuration file 'libpng-config' as a link to the]
+ [versioned version. This is done by default - use]
+ [--disable-unversioned-libpng-config to change this.]))
+AM_CONDITIONAL([DO_INSTALL_LIBPNG_CONFIG],
+ [test "$enable_unversioned_libpng_config" != "no"])
+
+# HOST-SPECIFIC OPTIONS
+# =====================
+#
+# DEFAULT
+# =======
+#
+AC_ARG_ENABLE([hardware-optimizations],
+ AS_HELP_STRING([[[--enable-hardware-optimizations]]],
+ [Enable hardware optimizations: =no/off, yes/on.]),
+ [case "$enableval" in
+ no|off)
+ # disable hardware optimization on all systems:
+ enable_arm_neon=no
+ AC_DEFINE([PNG_ARM_NEON_OPT], [0],
+ [Disable ARM_NEON optimizations])
+ enable_mips_msa=no
+ AC_DEFINE([PNG_MIPS_MSA_OPT], [0],
+ [Disable MIPS_MSA optimizations])
+ enable_mips_mmi=no
+ AC_DEFINE([PNG_MIPS_MMI_OPT], [0],
+ [Disable MIPS_MMI optimizations])
+ enable_powerpc_vsx=no
+ AC_DEFINE([PNG_POWERPC_VSX_OPT], [0],
+ [Disable POWERPC VSX optimizations])
+ enable_intel_sse=no
+ AC_DEFINE([PNG_INTEL_SSE_OPT], [0],
+ [Disable INTEL_SSE optimizations])
+ enable_loongarch_lsx=no
+ AC_DEFINE([PNG_LOONGARCH_LSX_OPT], [0],
+ [Disable LOONGARCH_LSX optimizations])
+ enable_riscv_rvv=no
+ AC_DEFINE([PNG_RISCV_RVV_OPT], [0],
+ [Disable RISC-V Vector optimizations])
+ ;;
+ *)
+ # allow enabling hardware optimization on any system:
+ case "$host_cpu" in
+ arm*|aarch64*)
+ enable_arm_neon=yes
+ AC_DEFINE([PNG_ARM_NEON_OPT], [2],
+ [Enable ARM_NEON optimizations])
+ ;;
+ mipsel*|mips64el*)
+ enable_mips_mmi=yes
+ enable_mips_msa=yes
+ AC_DEFINE([PNG_MIPS_MMI_OPT], [1],
+ [Enable MIPS_MMI optimizations])
+ AC_DEFINE([PNG_MIPS_MSA_OPT], [2],
+ [Enable MIPS_MSA optimizations])
+ ;;
+ i?86|x86_64)
+ enable_intel_sse=yes
+ AC_DEFINE([PNG_INTEL_SSE_OPT], [1],
+ [Enable Intel SSE optimizations])
+ ;;
+ powerpc*|ppc64*)
+ enable_powerpc_vsx=yes
+ AC_DEFINE([PNG_POWERPC_VSX_OPT], [2],
+ [Enable POWERPC VSX optimizations])
+ ;;
+ loongarch*)
+ enable_loongarch_lsx=yes
+ AC_DEFINE([PNG_LOONGARCH_LSX_OPT], [1],
+ [Enable LOONGARCH_LSX optimizations])
+ riscv*)
+ enable_riscv_rvv=yes
+ AC_DEFINE([PNG_RISCV_RVV_OPT], [2],
+ [Enable RISC-V Vector optimizations])
+ ;;
+ esac
+ ;;
+ esac])
+
+# ARM NEON
+# ========
+
+AC_ARG_ENABLE([arm-neon],
+ AS_HELP_STRING([[[--enable-arm-neon]]],
+ [Enable ARM NEON optimizations: =no/off, check, api, yes/on.]
+ [no/off: disable the optimizations;]
+ [check: use internal checking code (deprecated and poorly supported);]
+ [api: disable by default, enable by a call to png_set_option;]
+ [yes/on: turn on unconditionally.]
+ [If not specified: determined by the compiler.]),
+ [case "$enableval" in
+ no|off)
+ # disable the default enabling on __ARM_NEON__ systems:
+ AC_DEFINE([PNG_ARM_NEON_OPT], [0],
+ [Disable ARM Neon optimizations])
+ # Prevent inclusion of the assembler files below:
+ enable_arm_neon=no ;;
+ check)
+ AC_DEFINE([PNG_ARM_NEON_CHECK_SUPPORTED], [],
+ [Check for ARM Neon support at run-time]);;
+ api)
+ AC_DEFINE([PNG_ARM_NEON_API_SUPPORTED], [],
+ [Turn on ARM Neon optimizations at run-time]);;
+ yes|on)
+ AC_DEFINE([PNG_ARM_NEON_OPT], [2],
+ [Enable ARM Neon optimizations])
+ AC_MSG_WARN([--enable-arm-neon: please specify 'check' or 'api';]
+ [if you want the optimizations unconditionally,]
+ [pass '-mfpu=neon' to the compiler.]);;
+ *)
+ AC_MSG_ERROR([--enable-arm-neon=${enable_arm_neon}:]
+ [invalid argument])
+ esac])
+
+# Add ARM-specific files to all builds where $host_cpu is arm ('arm*') or
+# where ARM optimizations were explicitly requested. (This allows a fallback
+# if a future host CPU does not match 'arm*'.)
+
+AM_CONDITIONAL([PNG_ARM_NEON],
+ [test "$enable_arm_neon" != 'no' &&
+ case "$host_cpu" in
+ arm*|aarch64*) : ;;
+ *) test "$enable_arm_neon" != '' ;;
+ esac])
+
+# MIPS MSA
+# ========
+
+AC_ARG_ENABLE([mips-msa],
+ AS_HELP_STRING([[[--enable-mips-msa]]],
+ [Enable MIPS MSA optimizations: =no/off, check, api, yes/on.]
+ [no/off: disable the optimizations;]
+ [check: use internal checking code (deprecated and poorly supported);]
+ [api: disable by default, enable by a call to png_set_option;]
+ [yes/on: turn on unconditionally.]
+ [If not specified: determined by the compiler.]),
+ [case "$enableval" in
+ no|off)
+ # disable the default enabling on __mips_msa systems:
+ AC_DEFINE([PNG_MIPS_MSA_OPT], [0],
+ [Disable MIPS MSA optimizations])
+ # Prevent inclusion of the assembler files below:
+ enable_mips_msa=no ;;
+ check)
+ AC_DEFINE([PNG_MIPS_MSA_CHECK_SUPPORTED], [],
+ [Check for MIPS MSA support at run-time]);;
+ api)
+ AC_DEFINE([PNG_MIPS_MSA_API_SUPPORTED], [],
+ [Turn on MIPS MSA optimizations at run-time]);;
+ yes|on)
+ AC_DEFINE([PNG_MIPS_MSA_OPT], [2],
+ [Enable MIPS MSA optimizations])
+ AC_MSG_WARN([--enable-mips-msa: please specify 'check' or 'api';]
+ [if you want the optimizations unconditionally,]
+ [pass '-mmsa -mfp64' to the compiler.]);;
+ *)
+ AC_MSG_ERROR([--enable-mips-msa=${enable_mips_msa}:]
+ [invalid argument])
+ esac])
+
+# Add MIPS-specific files to all builds where $host_cpu is mips ('mips*') or
+# where MIPS optimizations were explicitly requested. (This allows a fallback
+# if a future host CPU does not match 'mips*'.)
+
+AM_CONDITIONAL([PNG_MIPS_MSA],
+ [test "$enable_mips_msa" != 'no' &&
+ case "$host_cpu" in
+ mipsel*|mips64el*) : ;;
+ esac])
+
+# MIPS MMI
+# ========
+
+AC_ARG_ENABLE([mips-mmi],
+ AS_HELP_STRING([[[--enable-mips-mmi]]],
+ [Enable MIPS MMI optimizations: =no/off, check, api, yes/on.]
+ [no/off: disable the optimizations;]
+ [check: use internal checking code (deprecated and poorly supported);]
+ [api: disable by default, enable by a call to png_set_option;]
+ [yes/on: turn on unconditionally.]
+ [If not specified: determined by the compiler.]),
+ [case "$enableval" in
+ no|off)
+ # disable the default enabling on __mips_mmi systems:
+ AC_DEFINE([PNG_MIPS_MMI_OPT], [0],
+ [Disable MIPS MMI optimizations])
+ # Prevent inclusion of the assembler files below:
+ enable_mips_mmi=no;;
+ check)
+ AC_DEFINE([PNG_MIPS_MMI_CHECK_SUPPORTED], [],
+ [Check for MIPS MMI support at run-time]);;
+ api)
+ AC_DEFINE([PNG_MIPS_MMI_API_SUPPORTED], [],
+ [Turn on MIPS MMI optimizations at run-time]);;
+ yes|on)
+ AC_DEFINE([PNG_MIPS_MMI_OPT], [1],
+ [Enable MIPS MMI optimizations])
+ AC_MSG_WARN([--enable-mips-mmi: please specify 'check' or 'api';]
+ [if you want the optimizations unconditionally]
+ [pass '-mloongson-mmi -march=loongson3a' to the compiler.]);;
+ *)
+ AC_MSG_ERROR([--enable-mips-mmi=${enable_mips_mmi}:]
+ [invalid argument])
+ esac])
+
+# Add MIPS specific files to all builds where the host_cpu is mips ('mips*') or
+# where MIPS optimizations were explicitly requested. (This allows a fallback
+# if a future host CPU does not match 'mips*'.)
+
+AM_CONDITIONAL([PNG_MIPS_MMI],
+ [test "$enable_mips_mmi" != 'no' &&
+ case "$host_cpu" in
+ mipsel*|mips64el*) : ;;
+ esac])
+
+# INTEL SSE
+# =========
+
+AC_ARG_ENABLE([intel-sse],
+ AS_HELP_STRING([[[--enable-intel-sse]]],
+ [Enable Intel SSE optimizations: =no/off, yes/on.]
+ [no/off: disable the optimizations;]
+ [yes/on: enable the optimizations.]
+ [If not specified: determined by the compiler.]),
+ [case "$enableval" in
+ no|off)
+ # disable the default enabling:
+ AC_DEFINE([PNG_INTEL_SSE_OPT], [0],
+ [Disable Intel SSE optimizations])
+ # Prevent inclusion of the assembler files below:
+ enable_intel_sse=no ;;
+ yes|on)
+ AC_DEFINE([PNG_INTEL_SSE_OPT], [1],
+ [Enable Intel SSE optimizations]);;
+ *)
+ AC_MSG_ERROR([--enable-intel-sse=${enable_intel_sse}:]
+ [invalid argument])
+ esac])
+
+# Add Intel-specific files to all builds where $host_cpu is Intel ('x86*') or
+# where Intel optimizations were explicitly requested. (This allows a fallback
+# if a future host CPU does not match 'x86*'.)
+AM_CONDITIONAL([PNG_INTEL_SSE],
+ [test "$enable_intel_sse" != 'no' &&
+ case "$host_cpu" in
+ i?86|x86_64) : ;;
+ *) test "$enable_intel_sse" != '' ;;
+ esac])
+
+# POWERPC VSX
+# ===========
+
+AC_ARG_ENABLE([powerpc-vsx],
+AS_HELP_STRING([[[--enable-powerpc-vsx]]],
+ [Enable POWERPC VSX optimizations: =no/off, check, api, yes/on.]
+ [no/off: disable the optimizations;]
+ [check: use internal checking code;]
+ [api: disable by default, enable by a call to png_set_option;]
+ [yes/on: turn on unconditionally.]
+ [If not specified: determined by the compiler.]),
+ [case "$enableval" in
+ no|off)
+ # disable the default enabling on __ppc64__ systems:
+ AC_DEFINE([PNG_POWERPC_VSX_OPT], [0],
+ [Disable POWERPC VSX optimizations])
+ # Prevent inclusion of the platform-specific files below:
+ enable_powerpc_vsx=no ;;
+ check)
+ AC_DEFINE([PNG_POWERPC_VSX_CHECK_SUPPORTED], [],
+ [Check for POWERPC VSX support at run-time])
+ AC_MSG_WARN([--enable-powerpc-vsx: please see contrib/powerpc/README]
+ [for the list of supported systems.]);;
+ api)
+ AC_DEFINE([PNG_POWERPC_VSX_API_SUPPORTED], [],
+ [Turn on POWERPC VSX optimizations at run-time]);;
+ yes|on)
+ AC_DEFINE([PNG_POWERPC_VSX_OPT], [2],
+ [Enable POWERPC VSX optimizations])
+ AC_MSG_WARN([--enable-powerpc-vsx: please specify 'check' or 'api';]
+ [if you want the optimizations unconditionally,]
+ [pass '-maltivec -mvsx' or '-mcpu=power8' to the compiler.]);;
+ *)
+ AC_MSG_ERROR([--enable-powerpc-vsx=${enable_powerpc_vsx}:]
+ [invalid argument])
+ esac])
+
+# Add PowerPC-specific files to all builds where $host_cpu is powerpc
+# ('powerpc*') or where PowerPC optimizations were explicitly requested.
+# (This allows a fallback if a future host CPU does not match 'powerpc*'.)
+
+AM_CONDITIONAL([PNG_POWERPC_VSX],
+ [test "$enable_powerpc_vsx" != 'no' &&
+ case "$host_cpu" in
+ powerpc*|ppc64*) : ;;
+ esac])
+
+# LOONGARCH LSX
+# =============
+
+AC_ARG_ENABLE([loongarch-lsx],
+ AS_HELP_STRING([[[--enable-loongarch-lsx]]],
+ [Enable LOONGARCH LSX optimizations: =no/off, yes/on:]
+ [no/off: disable the optimizations;]
+ [yes/on: turn on unconditionally.]
+ [If not specified: determined by the compiler.]),
+ [case "$enableval" in
+ no|off)
+ # disable the default enabling on __loongarch_simd systems:
+ AC_DEFINE([PNG_LOONGARCH_LSX_OPT], [0],
+ [Disable LOONGARCH LSX optimizations])
+ # Prevent inclusion of the assembler files below:
+ enable_loongarch_lsx=no;;
+ yes|on)
+ AC_DEFINE([PNG_LOONGARCH_LSX_OPT], [1],
+ [Enable LOONGARCH LSX optimizations])
+ ;;
+ *)
+ AC_MSG_ERROR([--enable-loongarch-lsx=${enable_loongarch_lsx}:]
+ [invalid argument])
+ esac])
+
+if test "$enable_loongarch_lsx" != "no" &&
+ case "$host_cpu" in
+ loongarch*) : ;;
+ *) test "$enable_loongarch_lsx" != '' ;;
+ esac
+then
+ compiler_support_loongarch_lsx=no
+ AC_MSG_CHECKING(whether to use LoongArch LSX intrinsics)
+ save_CFLAGS="$CFLAGS"
+ LSX_CFLAGS="${LSX_CFLAGS:-"-mlsx"}"
+ CFLAGS="$CFLAGS $LSX_CFLAGS"
+ AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
+#include
+int main(){
+ __m128i a, b, c;
+ a = __lsx_vadd_w(b, c);
+ return 0;
+}]])],compiler_support_loongarch_lsx=yes)
+ CFLAGS="$save_CFLAGS"
+ AC_MSG_RESULT($compiler_support_loongarch_lsx)
+ if test "$compiler_support_loongarch_lsx" = "yes"; then
+ AC_DEFINE([PNG_LOONGARCH_LSX_OPT], [1],
+ [Enable LOONGARCH LSX optimizations])
+ else
+ AC_MSG_WARN([Compiler does not support loongarch LSX.])
+ fi
+fi
+
+# Add LoongArch specific files to all builds where the host_cpu is loongarch
+# ('loongarch*') or where LoongArch optimizations were explicitly requested.
+# (This allows a fallback if a future host CPU does not match 'loongarch*'.)
+
+AM_CONDITIONAL([PNG_LOONGARCH_LSX],
+ [test "$enable_loongarch_lsx" != "no" &&
+ test "$compiler_support_loongarch_lsx" = "yes" &&
+ case "$host_cpu" in
+ loongarch*) : ;;
+ *) test "$enable_loongarch_lsx" != '' ;;
+ esac])
+
+# RISC-V
+# ======
+#
+# RISC-V Vector support.
+
+AC_ARG_ENABLE([riscv-vector],
+AS_HELP_STRING([[[--enable-riscv-rvv]]],
+ [Enable RISC-V Vector optimizations: =no/off, check, api, yes/on:]
+ [no/off: disable the optimizations; check: use internal checking code]
+ [api: disable by default, enable by a call to png_set_option]
+ [yes/on: turn on unconditionally.]
+ [If not specified: determined by the compiler.]),
+ [case "$enableval" in
+ no|off)
+ # disable the default enabling on __riscv systems:
+ AC_DEFINE([PNG_RISCV_RVV_OPT], [0],
+ [Disable RISC-V Vector optimizations])
+ # Prevent inclusion of the platform-specific files below:
+ enable_riscv_rvv=no ;;
+ check)
+ AC_DEFINE([PNG_RISCV_RVV_CHECK_SUPPORTED], [],
+ [Check for RISC-V Vector support at run-time])
+ AC_MSG_WARN([--enable-riscv-rvv Please check contrib/riscv-vector/README file]
+ [for the list of supported OSes.]);;
+ api)
+ AC_DEFINE([PNG_RISCV_RVV_API_SUPPORTED], [],
+ [Turn on RISC-V Vector optimizations at run-time]);;
+ yes|on)
+ AC_DEFINE([PNG_RISCV_RVV_OPT], [2],
+ [Enable RISC-V Vector optimizations])
+ AC_MSG_WARN([--enable-riscv-rvv: please specify 'check' or 'api', if]
+ [you want the optimizations unconditionally pass e.g. '-march=rv64gcv']
+ [to the compiler.]);;
+ *)
+ AC_MSG_ERROR([--enable-riscv-rvv=${enable_riscv_rvv}: invalid value])
+ esac])
+
+# Add RISC-V-specific files to all builds where $host_cpu is riscv ('riscv*')
+# or where RISC-V optimizations were explicitly requested (this allows a fallback
+# if a future host CPU does not match 'riscv*')
+
+AM_CONDITIONAL([PNG_RISCV_RVV],
+ [test "$enable_riscv_rvv" != 'no' &&
+ case "$host_cpu" in
+ riscv*) : ;;
+ esac])
+
+AC_MSG_NOTICE([[Extra options for compiler: $PNG_COPTS]])
+
+# Config files, substituting as above
+AC_CONFIG_FILES([Makefile libpng.pc:libpng.pc.in])
+AC_CONFIG_FILES([libpng-config:libpng-config.in],
+ [chmod +x libpng-config])
+
+AC_OUTPUT
diff --git a/libs/imagequant/external/libpng/intel/filter_sse2_intrinsics.c b/libs/imagequant/external/libpng/intel/filter_sse2_intrinsics.c
new file mode 100644
index 00000000..2993f650
--- /dev/null
+++ b/libs/imagequant/external/libpng/intel/filter_sse2_intrinsics.c
@@ -0,0 +1,390 @@
+/* filter_sse2_intrinsics.c - SSE2 optimized filter functions
+ *
+ * Copyright (c) 2018 Cosmin Truta
+ * Copyright (c) 2016-2017 Glenn Randers-Pehrson
+ * Written by Mike Klein and Matt Sarett
+ * Derived from arm/filter_neon_intrinsics.c
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "../pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+#if PNG_INTEL_SSE_IMPLEMENTATION > 0
+
+#include
+
+/* Functions in this file look at most 3 pixels (a,b,c) to predict the 4th (d).
+ * They're positioned like this:
+ * prev: c b
+ * row: a d
+ * The Sub filter predicts d=a, Avg d=(a+b)/2, and Paeth predicts d to be
+ * whichever of a, b, or c is closest to p=a+b-c.
+ */
+
+static __m128i load4(const void* p) {
+ int tmp;
+ memcpy(&tmp, p, sizeof(tmp));
+ return _mm_cvtsi32_si128(tmp);
+}
+
+static void store4(void* p, __m128i v) {
+ int tmp = _mm_cvtsi128_si32(v);
+ memcpy(p, &tmp, sizeof(int));
+}
+
+static __m128i load3(const void* p) {
+ png_uint_32 tmp = 0;
+ memcpy(&tmp, p, 3);
+ return _mm_cvtsi32_si128(tmp);
+}
+
+static void store3(void* p, __m128i v) {
+ int tmp = _mm_cvtsi128_si32(v);
+ memcpy(p, &tmp, 3);
+}
+
+void png_read_filter_row_sub3_sse2(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev)
+{
+ /* The Sub filter predicts each pixel as the previous pixel, a.
+ * There is no pixel to the left of the first pixel. It's encoded directly.
+ * That works with our main loop if we just say that left pixel was zero.
+ */
+ size_t rb;
+
+ __m128i a, d = _mm_setzero_si128();
+
+ png_debug(1, "in png_read_filter_row_sub3_sse2");
+
+ rb = row_info->rowbytes;
+ while (rb >= 4) {
+ a = d; d = load4(row);
+ d = _mm_add_epi8(d, a);
+ store3(row, d);
+
+ row += 3;
+ rb -= 3;
+ }
+ if (rb > 0) {
+ a = d; d = load3(row);
+ d = _mm_add_epi8(d, a);
+ store3(row, d);
+
+ row += 3;
+ rb -= 3;
+ }
+ PNG_UNUSED(prev)
+}
+
+void png_read_filter_row_sub4_sse2(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev)
+{
+ /* The Sub filter predicts each pixel as the previous pixel, a.
+ * There is no pixel to the left of the first pixel. It's encoded directly.
+ * That works with our main loop if we just say that left pixel was zero.
+ */
+ size_t rb;
+
+ __m128i a, d = _mm_setzero_si128();
+
+ png_debug(1, "in png_read_filter_row_sub4_sse2");
+
+ rb = row_info->rowbytes+4;
+ while (rb > 4) {
+ a = d; d = load4(row);
+ d = _mm_add_epi8(d, a);
+ store4(row, d);
+
+ row += 4;
+ rb -= 4;
+ }
+ PNG_UNUSED(prev)
+}
+
+void png_read_filter_row_avg3_sse2(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev)
+{
+ /* The Avg filter predicts each pixel as the (truncated) average of a and b.
+ * There's no pixel to the left of the first pixel. Luckily, it's
+ * predicted to be half of the pixel above it. So again, this works
+ * perfectly with our loop if we make sure a starts at zero.
+ */
+
+ size_t rb;
+
+ const __m128i zero = _mm_setzero_si128();
+
+ __m128i b;
+ __m128i a, d = zero;
+
+ png_debug(1, "in png_read_filter_row_avg3_sse2");
+ rb = row_info->rowbytes;
+ while (rb >= 4) {
+ __m128i avg;
+ b = load4(prev);
+ a = d; d = load4(row );
+
+ /* PNG requires a truncating average, so we can't just use _mm_avg_epu8 */
+ avg = _mm_avg_epu8(a,b);
+ /* ...but we can fix it up by subtracting off 1 if it rounded up. */
+ avg = _mm_sub_epi8(avg, _mm_and_si128(_mm_xor_si128(a,b),
+ _mm_set1_epi8(1)));
+ d = _mm_add_epi8(d, avg);
+ store3(row, d);
+
+ prev += 3;
+ row += 3;
+ rb -= 3;
+ }
+ if (rb > 0) {
+ __m128i avg;
+ b = load3(prev);
+ a = d; d = load3(row );
+
+ /* PNG requires a truncating average, so we can't just use _mm_avg_epu8 */
+ avg = _mm_avg_epu8(a,b);
+ /* ...but we can fix it up by subtracting off 1 if it rounded up. */
+ avg = _mm_sub_epi8(avg, _mm_and_si128(_mm_xor_si128(a,b),
+ _mm_set1_epi8(1)));
+
+ d = _mm_add_epi8(d, avg);
+ store3(row, d);
+
+ prev += 3;
+ row += 3;
+ rb -= 3;
+ }
+}
+
+void png_read_filter_row_avg4_sse2(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev)
+{
+ /* The Avg filter predicts each pixel as the (truncated) average of a and b.
+ * There's no pixel to the left of the first pixel. Luckily, it's
+ * predicted to be half of the pixel above it. So again, this works
+ * perfectly with our loop if we make sure a starts at zero.
+ */
+ size_t rb;
+ const __m128i zero = _mm_setzero_si128();
+ __m128i b;
+ __m128i a, d = zero;
+
+ png_debug(1, "in png_read_filter_row_avg4_sse2");
+
+ rb = row_info->rowbytes+4;
+ while (rb > 4) {
+ __m128i avg;
+ b = load4(prev);
+ a = d; d = load4(row );
+
+ /* PNG requires a truncating average, so we can't just use _mm_avg_epu8 */
+ avg = _mm_avg_epu8(a,b);
+ /* ...but we can fix it up by subtracting off 1 if it rounded up. */
+ avg = _mm_sub_epi8(avg, _mm_and_si128(_mm_xor_si128(a,b),
+ _mm_set1_epi8(1)));
+
+ d = _mm_add_epi8(d, avg);
+ store4(row, d);
+
+ prev += 4;
+ row += 4;
+ rb -= 4;
+ }
+}
+
+/* Returns |x| for 16-bit lanes. */
+static __m128i abs_i16(__m128i x) {
+#if PNG_INTEL_SSE_IMPLEMENTATION >= 2
+ return _mm_abs_epi16(x);
+#else
+ /* Read this all as, return x<0 ? -x : x.
+ * To negate two's complement, you flip all the bits then add 1.
+ */
+ __m128i is_negative = _mm_cmplt_epi16(x, _mm_setzero_si128());
+
+ /* Flip negative lanes. */
+ x = _mm_xor_si128(x, is_negative);
+
+ /* +1 to negative lanes, else +0. */
+ x = _mm_sub_epi16(x, is_negative);
+ return x;
+#endif
+}
+
+/* Bytewise c ? t : e. */
+static __m128i if_then_else(__m128i c, __m128i t, __m128i e) {
+#if PNG_INTEL_SSE_IMPLEMENTATION >= 3
+ return _mm_blendv_epi8(e,t,c);
+#else
+ return _mm_or_si128(_mm_and_si128(c, t), _mm_andnot_si128(c, e));
+#endif
+}
+
+void png_read_filter_row_paeth3_sse2(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev)
+{
+ /* Paeth tries to predict pixel d using the pixel to the left of it, a,
+ * and two pixels from the previous row, b and c:
+ * prev: c b
+ * row: a d
+ * The Paeth function predicts d to be whichever of a, b, or c is nearest to
+ * p=a+b-c.
+ *
+ * The first pixel has no left context, and so uses an Up filter, p = b.
+ * This works naturally with our main loop's p = a+b-c if we force a and c
+ * to zero.
+ * Here we zero b and d, which become c and a respectively at the start of
+ * the loop.
+ */
+ size_t rb;
+ const __m128i zero = _mm_setzero_si128();
+ __m128i c, b = zero,
+ a, d = zero;
+
+ png_debug(1, "in png_read_filter_row_paeth3_sse2");
+
+ rb = row_info->rowbytes;
+ while (rb >= 4) {
+ /* It's easiest to do this math (particularly, deal with pc) with 16-bit
+ * intermediates.
+ */
+ __m128i pa,pb,pc,smallest,nearest;
+ c = b; b = _mm_unpacklo_epi8(load4(prev), zero);
+ a = d; d = _mm_unpacklo_epi8(load4(row ), zero);
+
+ /* (p-a) == (a+b-c - a) == (b-c) */
+
+ pa = _mm_sub_epi16(b,c);
+
+ /* (p-b) == (a+b-c - b) == (a-c) */
+ pb = _mm_sub_epi16(a,c);
+
+ /* (p-c) == (a+b-c - c) == (a+b-c-c) == (b-c)+(a-c) */
+ pc = _mm_add_epi16(pa,pb);
+
+ pa = abs_i16(pa); /* |p-a| */
+ pb = abs_i16(pb); /* |p-b| */
+ pc = abs_i16(pc); /* |p-c| */
+
+ smallest = _mm_min_epi16(pc, _mm_min_epi16(pa, pb));
+
+ /* Paeth breaks ties favoring a over b over c. */
+ nearest = if_then_else(_mm_cmpeq_epi16(smallest, pa), a,
+ if_then_else(_mm_cmpeq_epi16(smallest, pb), b,
+ c));
+
+ /* Note `_epi8`: we need addition to wrap modulo 255. */
+ d = _mm_add_epi8(d, nearest);
+ store3(row, _mm_packus_epi16(d,d));
+
+ prev += 3;
+ row += 3;
+ rb -= 3;
+ }
+ if (rb > 0) {
+ /* It's easiest to do this math (particularly, deal with pc) with 16-bit
+ * intermediates.
+ */
+ __m128i pa,pb,pc,smallest,nearest;
+ c = b; b = _mm_unpacklo_epi8(load3(prev), zero);
+ a = d; d = _mm_unpacklo_epi8(load3(row ), zero);
+
+ /* (p-a) == (a+b-c - a) == (b-c) */
+ pa = _mm_sub_epi16(b,c);
+
+ /* (p-b) == (a+b-c - b) == (a-c) */
+ pb = _mm_sub_epi16(a,c);
+
+ /* (p-c) == (a+b-c - c) == (a+b-c-c) == (b-c)+(a-c) */
+ pc = _mm_add_epi16(pa,pb);
+
+ pa = abs_i16(pa); /* |p-a| */
+ pb = abs_i16(pb); /* |p-b| */
+ pc = abs_i16(pc); /* |p-c| */
+
+ smallest = _mm_min_epi16(pc, _mm_min_epi16(pa, pb));
+
+ /* Paeth breaks ties favoring a over b over c. */
+ nearest = if_then_else(_mm_cmpeq_epi16(smallest, pa), a,
+ if_then_else(_mm_cmpeq_epi16(smallest, pb), b,
+ c));
+
+ /* Note `_epi8`: we need addition to wrap modulo 255. */
+ d = _mm_add_epi8(d, nearest);
+ store3(row, _mm_packus_epi16(d,d));
+
+ prev += 3;
+ row += 3;
+ rb -= 3;
+ }
+}
+
+void png_read_filter_row_paeth4_sse2(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev)
+{
+ /* Paeth tries to predict pixel d using the pixel to the left of it, a,
+ * and two pixels from the previous row, b and c:
+ * prev: c b
+ * row: a d
+ * The Paeth function predicts d to be whichever of a, b, or c is nearest to
+ * p=a+b-c.
+ *
+ * The first pixel has no left context, and so uses an Up filter, p = b.
+ * This works naturally with our main loop's p = a+b-c if we force a and c
+ * to zero.
+ * Here we zero b and d, which become c and a respectively at the start of
+ * the loop.
+ */
+ size_t rb;
+ const __m128i zero = _mm_setzero_si128();
+ __m128i pa,pb,pc,smallest,nearest;
+ __m128i c, b = zero,
+ a, d = zero;
+
+ png_debug(1, "in png_read_filter_row_paeth4_sse2");
+
+ rb = row_info->rowbytes+4;
+ while (rb > 4) {
+ /* It's easiest to do this math (particularly, deal with pc) with 16-bit
+ * intermediates.
+ */
+ c = b; b = _mm_unpacklo_epi8(load4(prev), zero);
+ a = d; d = _mm_unpacklo_epi8(load4(row ), zero);
+
+ /* (p-a) == (a+b-c - a) == (b-c) */
+ pa = _mm_sub_epi16(b,c);
+
+ /* (p-b) == (a+b-c - b) == (a-c) */
+ pb = _mm_sub_epi16(a,c);
+
+ /* (p-c) == (a+b-c - c) == (a+b-c-c) == (b-c)+(a-c) */
+ pc = _mm_add_epi16(pa,pb);
+
+ pa = abs_i16(pa); /* |p-a| */
+ pb = abs_i16(pb); /* |p-b| */
+ pc = abs_i16(pc); /* |p-c| */
+
+ smallest = _mm_min_epi16(pc, _mm_min_epi16(pa, pb));
+
+ /* Paeth breaks ties favoring a over b over c. */
+ nearest = if_then_else(_mm_cmpeq_epi16(smallest, pa), a,
+ if_then_else(_mm_cmpeq_epi16(smallest, pb), b,
+ c));
+
+ /* Note `_epi8`: we need addition to wrap modulo 255. */
+ d = _mm_add_epi8(d, nearest);
+ store4(row, _mm_packus_epi16(d,d));
+
+ prev += 4;
+ row += 4;
+ rb -= 4;
+ }
+}
+
+#endif /* PNG_INTEL_SSE_IMPLEMENTATION > 0 */
+#endif /* READ */
diff --git a/libs/imagequant/external/libpng/intel/intel_init.c b/libs/imagequant/external/libpng/intel/intel_init.c
new file mode 100644
index 00000000..9e4610d2
--- /dev/null
+++ b/libs/imagequant/external/libpng/intel/intel_init.c
@@ -0,0 +1,51 @@
+/* intel_init.c - SSE2 optimized filter functions
+ *
+ * Copyright (c) 2018 Cosmin Truta
+ * Copyright (c) 2016-2017 Glenn Randers-Pehrson
+ * Written by Mike Klein and Matt Sarett, Google, Inc.
+ * Derived from arm/arm_init.c
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "../pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+#if PNG_INTEL_SSE_IMPLEMENTATION > 0
+
+void
+png_init_filter_functions_sse2(png_structp pp, unsigned int bpp)
+{
+ /* The techniques used to implement each of these filters in SSE operate on
+ * one pixel at a time.
+ * So they generally speed up 3bpp images about 3x, 4bpp images about 4x.
+ * They can scale up to 6 and 8 bpp images and down to 2 bpp images,
+ * but they'd not likely have any benefit for 1bpp images.
+ * Most of these can be implemented using only MMX and 64-bit registers,
+ * but they end up a bit slower than using the equally-ubiquitous SSE2.
+ */
+ png_debug(1, "in png_init_filter_functions_sse2");
+ if (bpp == 3)
+ {
+ pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_sse2;
+ pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_sse2;
+ pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+ png_read_filter_row_paeth3_sse2;
+ }
+ else if (bpp == 4)
+ {
+ pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_sse2;
+ pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_sse2;
+ pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+ png_read_filter_row_paeth4_sse2;
+ }
+
+ /* No need optimize PNG_FILTER_VALUE_UP. The compiler should
+ * autovectorize.
+ */
+}
+
+#endif /* PNG_INTEL_SSE_IMPLEMENTATION > 0 */
+#endif /* PNG_READ_SUPPORTED */
diff --git a/libs/imagequant/external/libpng/libpng-config.in b/libs/imagequant/external/libpng/libpng-config.in
new file mode 100644
index 00000000..69bf8e33
--- /dev/null
+++ b/libs/imagequant/external/libpng/libpng-config.in
@@ -0,0 +1,127 @@
+#! /bin/sh
+
+# libpng-config
+# provides configuration info for libpng.
+
+# Copyright (C) 2002, 2004, 2006, 2007 Glenn Randers-Pehrson
+
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+# Modeled after libxml-config.
+
+version="@PNGLIB_VERSION@"
+prefix="@prefix@"
+exec_prefix="@exec_prefix@"
+libdir="@libdir@"
+includedir="@includedir@/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@"
+libs="-lpng@PNGLIB_MAJOR@@PNGLIB_MINOR@"
+all_libs="-lpng@PNGLIB_MAJOR@@PNGLIB_MINOR@ @LIBS@"
+I_opts="-I${includedir}"
+L_opts="-L${libdir}"
+R_opts=""
+cppflags=""
+ccopts=""
+ldopts=""
+
+usage()
+{
+ cat < 8)
+ png_error(png_ptr, "Too many bytes for PNG signature");
+
+ png_ptr->sig_bytes = (png_byte)nb;
+}
+
+/* Checks whether the supplied bytes match the PNG signature. We allow
+ * checking less than the full 8-byte signature so that those apps that
+ * already read the first few bytes of a file to determine the file type
+ * can simply check the remaining bytes for extra assurance. Returns
+ * an integer less than, equal to, or greater than zero if sig is found,
+ * respectively, to be less than, to match, or be greater than the correct
+ * PNG signature (this is the same behavior as strcmp, memcmp, etc).
+ */
+int PNGAPI
+png_sig_cmp(png_const_bytep sig, size_t start, size_t num_to_check)
+{
+ static const png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+
+ if (num_to_check > 8)
+ num_to_check = 8;
+
+ else if (num_to_check < 1)
+ return -1;
+
+ if (start > 7)
+ return -1;
+
+ if (start + num_to_check > 8)
+ num_to_check = 8 - start;
+
+ return memcmp(&sig[start], &png_signature[start], num_to_check);
+}
+
+#endif /* READ */
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+/* Function to allocate memory for zlib */
+PNG_FUNCTION(voidpf /* PRIVATE */,
+png_zalloc,(voidpf png_ptr, uInt items, uInt size),PNG_ALLOCATED)
+{
+ png_alloc_size_t num_bytes = size;
+
+ if (png_ptr == NULL)
+ return NULL;
+
+ if (items >= (~(png_alloc_size_t)0)/size)
+ {
+ png_warning (png_voidcast(png_structrp, png_ptr),
+ "Potential overflow in png_zalloc()");
+ return NULL;
+ }
+
+ num_bytes *= items;
+ return png_malloc_warn(png_voidcast(png_structrp, png_ptr), num_bytes);
+}
+
+/* Function to free memory for zlib */
+void /* PRIVATE */
+png_zfree(voidpf png_ptr, voidpf ptr)
+{
+ png_free(png_voidcast(png_const_structrp,png_ptr), ptr);
+}
+
+/* Reset the CRC variable to 32 bits of 1's. Care must be taken
+ * in case CRC is > 32 bits to leave the top bits 0.
+ */
+void /* PRIVATE */
+png_reset_crc(png_structrp png_ptr)
+{
+ /* The cast is safe because the crc is a 32-bit value. */
+ png_ptr->crc = (png_uint_32)crc32(0, Z_NULL, 0);
+}
+
+/* Calculate the CRC over a section of data. We can only pass as
+ * much data to this routine as the largest single buffer size. We
+ * also check that this data will actually be used before going to the
+ * trouble of calculating it.
+ */
+void /* PRIVATE */
+png_calculate_crc(png_structrp png_ptr, png_const_bytep ptr, size_t length)
+{
+ int need_crc = 1;
+
+ if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0)
+ {
+ if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
+ (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
+ need_crc = 0;
+ }
+
+ else /* critical */
+ {
+ if ((png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) != 0)
+ need_crc = 0;
+ }
+
+ /* 'uLong' is defined in zlib.h as unsigned long; this means that on some
+ * systems it is a 64-bit value. crc32, however, returns 32 bits so the
+ * following cast is safe. 'uInt' may be no more than 16 bits, so it is
+ * necessary to perform a loop here.
+ */
+ if (need_crc != 0 && length > 0)
+ {
+ uLong crc = png_ptr->crc; /* Should never issue a warning */
+
+ do
+ {
+ uInt safe_length = (uInt)length;
+#ifndef __COVERITY__
+ if (safe_length == 0)
+ safe_length = (uInt)-1; /* evil, but safe */
+#endif
+
+ crc = crc32(crc, ptr, safe_length);
+
+ /* The following should never issue compiler warnings; if they do the
+ * target system has characteristics that will probably violate other
+ * assumptions within the libpng code.
+ */
+ ptr += safe_length;
+ length -= safe_length;
+ }
+ while (length > 0);
+
+ /* And the following is always safe because the crc is only 32 bits. */
+ png_ptr->crc = (png_uint_32)crc;
+ }
+}
+
+/* Check a user supplied version number, called from both read and write
+ * functions that create a png_struct.
+ */
+int
+png_user_version_check(png_structrp png_ptr, png_const_charp user_png_ver)
+{
+ /* Libpng versions 1.0.0 and later are binary compatible if the version
+ * string matches through the second '.'; we must recompile any
+ * applications that use any older library version.
+ */
+
+ if (user_png_ver != NULL)
+ {
+ int i = -1;
+ int found_dots = 0;
+
+ do
+ {
+ i++;
+ if (user_png_ver[i] != PNG_LIBPNG_VER_STRING[i])
+ png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
+ if (user_png_ver[i] == '.')
+ found_dots++;
+ } while (found_dots < 2 && user_png_ver[i] != 0 &&
+ PNG_LIBPNG_VER_STRING[i] != 0);
+ }
+
+ else
+ png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
+
+ if ((png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH) != 0)
+ {
+#ifdef PNG_WARNINGS_SUPPORTED
+ size_t pos = 0;
+ char m[128];
+
+ pos = png_safecat(m, (sizeof m), pos,
+ "Application built with libpng-");
+ pos = png_safecat(m, (sizeof m), pos, user_png_ver);
+ pos = png_safecat(m, (sizeof m), pos, " but running with ");
+ pos = png_safecat(m, (sizeof m), pos, PNG_LIBPNG_VER_STRING);
+ PNG_UNUSED(pos)
+
+ png_warning(png_ptr, m);
+#endif
+
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ png_ptr->flags = 0;
+#endif
+
+ return 0;
+ }
+
+ /* Success return. */
+ return 1;
+}
+
+/* Generic function to create a png_struct for either read or write - this
+ * contains the common initialization.
+ */
+PNG_FUNCTION(png_structp /* PRIVATE */,
+png_create_png_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+ png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
+{
+ png_struct create_struct;
+# ifdef PNG_SETJMP_SUPPORTED
+ jmp_buf create_jmp_buf;
+# endif
+
+ /* This temporary stack-allocated structure is used to provide a place to
+ * build enough context to allow the user provided memory allocator (if any)
+ * to be called.
+ */
+ memset(&create_struct, 0, (sizeof create_struct));
+
+# ifdef PNG_USER_LIMITS_SUPPORTED
+ create_struct.user_width_max = PNG_USER_WIDTH_MAX;
+ create_struct.user_height_max = PNG_USER_HEIGHT_MAX;
+
+# ifdef PNG_USER_CHUNK_CACHE_MAX
+ create_struct.user_chunk_cache_max = PNG_USER_CHUNK_CACHE_MAX;
+# endif
+
+# if PNG_USER_CHUNK_MALLOC_MAX > 0 /* default to compile-time limit */
+ create_struct.user_chunk_malloc_max = PNG_USER_CHUNK_MALLOC_MAX;
+
+ /* No compile-time limit, so initialize to the system limit: */
+# elif defined PNG_MAX_MALLOC_64K /* legacy system limit */
+ create_struct.user_chunk_malloc_max = 65536U;
+
+# else /* modern system limit SIZE_MAX (C99) */
+ create_struct.user_chunk_malloc_max = PNG_SIZE_MAX;
+# endif
+# endif
+
+ /* The following two API calls simply set fields in png_struct, so it is safe
+ * to do them now even though error handling is not yet set up.
+ */
+# ifdef PNG_USER_MEM_SUPPORTED
+ png_set_mem_fn(&create_struct, mem_ptr, malloc_fn, free_fn);
+# else
+ PNG_UNUSED(mem_ptr)
+ PNG_UNUSED(malloc_fn)
+ PNG_UNUSED(free_fn)
+# endif
+
+ /* (*error_fn) can return control to the caller after the error_ptr is set,
+ * this will result in a memory leak unless the error_fn does something
+ * extremely sophisticated. The design lacks merit but is implicit in the
+ * API.
+ */
+ png_set_error_fn(&create_struct, error_ptr, error_fn, warn_fn);
+
+# ifdef PNG_SETJMP_SUPPORTED
+ if (!setjmp(create_jmp_buf))
+# endif
+ {
+# ifdef PNG_SETJMP_SUPPORTED
+ /* Temporarily fake out the longjmp information until we have
+ * successfully completed this function. This only works if we have
+ * setjmp() support compiled in, but it is safe - this stuff should
+ * never happen.
+ */
+ create_struct.jmp_buf_ptr = &create_jmp_buf;
+ create_struct.jmp_buf_size = 0; /*stack allocation*/
+ create_struct.longjmp_fn = longjmp;
+# endif
+ /* Call the general version checker (shared with read and write code):
+ */
+ if (png_user_version_check(&create_struct, user_png_ver) != 0)
+ {
+ png_structrp png_ptr = png_voidcast(png_structrp,
+ png_malloc_warn(&create_struct, (sizeof *png_ptr)));
+
+ if (png_ptr != NULL)
+ {
+ /* png_ptr->zstream holds a back-pointer to the png_struct, so
+ * this can only be done now:
+ */
+ create_struct.zstream.zalloc = png_zalloc;
+ create_struct.zstream.zfree = png_zfree;
+ create_struct.zstream.opaque = png_ptr;
+
+# ifdef PNG_SETJMP_SUPPORTED
+ /* Eliminate the local error handling: */
+ create_struct.jmp_buf_ptr = NULL;
+ create_struct.jmp_buf_size = 0;
+ create_struct.longjmp_fn = 0;
+# endif
+
+ *png_ptr = create_struct;
+
+ /* This is the successful return point */
+ return png_ptr;
+ }
+ }
+ }
+
+ /* A longjmp because of a bug in the application storage allocator or a
+ * simple failure to allocate the png_struct.
+ */
+ return NULL;
+}
+
+/* Allocate the memory for an info_struct for the application. */
+PNG_FUNCTION(png_infop,PNGAPI
+png_create_info_struct,(png_const_structrp png_ptr),PNG_ALLOCATED)
+{
+ png_inforp info_ptr;
+
+ png_debug(1, "in png_create_info_struct");
+
+ if (png_ptr == NULL)
+ return NULL;
+
+ /* Use the internal API that does not (or at least should not) error out, so
+ * that this call always returns ok. The application typically sets up the
+ * error handling *after* creating the info_struct because this is the way it
+ * has always been done in 'example.c'.
+ */
+ info_ptr = png_voidcast(png_inforp, png_malloc_base(png_ptr,
+ (sizeof *info_ptr)));
+
+ if (info_ptr != NULL)
+ memset(info_ptr, 0, (sizeof *info_ptr));
+
+ return info_ptr;
+}
+
+/* This function frees the memory associated with a single info struct.
+ * Normally, one would use either png_destroy_read_struct() or
+ * png_destroy_write_struct() to free an info struct, but this may be
+ * useful for some applications. From libpng 1.6.0 this function is also used
+ * internally to implement the png_info release part of the 'struct' destroy
+ * APIs. This ensures that all possible approaches free the same data (all of
+ * it).
+ */
+void PNGAPI
+png_destroy_info_struct(png_const_structrp png_ptr, png_infopp info_ptr_ptr)
+{
+ png_inforp info_ptr = NULL;
+
+ png_debug(1, "in png_destroy_info_struct");
+
+ if (png_ptr == NULL)
+ return;
+
+ if (info_ptr_ptr != NULL)
+ info_ptr = *info_ptr_ptr;
+
+ if (info_ptr != NULL)
+ {
+ /* Do this first in case of an error below; if the app implements its own
+ * memory management this can lead to png_free calling png_error, which
+ * will abort this routine and return control to the app error handler.
+ * An infinite loop may result if it then tries to free the same info
+ * ptr.
+ */
+ *info_ptr_ptr = NULL;
+
+ png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
+ memset(info_ptr, 0, (sizeof *info_ptr));
+ png_free(png_ptr, info_ptr);
+ }
+}
+
+/* Initialize the info structure. This is now an internal function (0.89)
+ * and applications using it are urged to use png_create_info_struct()
+ * instead. Use deprecated in 1.6.0, internal use removed (used internally it
+ * is just a memset).
+ *
+ * NOTE: it is almost inconceivable that this API is used because it bypasses
+ * the user-memory mechanism and the user error handling/warning mechanisms in
+ * those cases where it does anything other than a memset.
+ */
+PNG_FUNCTION(void,PNGAPI
+png_info_init_3,(png_infopp ptr_ptr, size_t png_info_struct_size),
+ PNG_DEPRECATED)
+{
+ png_inforp info_ptr = *ptr_ptr;
+
+ png_debug(1, "in png_info_init_3");
+
+ if (info_ptr == NULL)
+ return;
+
+ if ((sizeof (png_info)) > png_info_struct_size)
+ {
+ *ptr_ptr = NULL;
+ /* The following line is why this API should not be used: */
+ free(info_ptr);
+ info_ptr = png_voidcast(png_inforp, png_malloc_base(NULL,
+ (sizeof *info_ptr)));
+ if (info_ptr == NULL)
+ return;
+ *ptr_ptr = info_ptr;
+ }
+
+ /* Set everything to 0 */
+ memset(info_ptr, 0, (sizeof *info_ptr));
+}
+
+void PNGAPI
+png_data_freer(png_const_structrp png_ptr, png_inforp info_ptr,
+ int freer, png_uint_32 mask)
+{
+ png_debug(1, "in png_data_freer");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ if (freer == PNG_DESTROY_WILL_FREE_DATA)
+ info_ptr->free_me |= mask;
+
+ else if (freer == PNG_USER_WILL_FREE_DATA)
+ info_ptr->free_me &= ~mask;
+
+ else
+ png_error(png_ptr, "Unknown freer parameter in png_data_freer");
+}
+
+void PNGAPI
+png_free_data(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 mask,
+ int num)
+{
+ png_debug(1, "in png_free_data");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+#ifdef PNG_TEXT_SUPPORTED
+ /* Free text item num or (if num == -1) all text items */
+ if (info_ptr->text != NULL &&
+ ((mask & PNG_FREE_TEXT) & info_ptr->free_me) != 0)
+ {
+ if (num != -1)
+ {
+ png_free(png_ptr, info_ptr->text[num].key);
+ info_ptr->text[num].key = NULL;
+ }
+
+ else
+ {
+ int i;
+
+ for (i = 0; i < info_ptr->num_text; i++)
+ png_free(png_ptr, info_ptr->text[i].key);
+
+ png_free(png_ptr, info_ptr->text);
+ info_ptr->text = NULL;
+ info_ptr->num_text = 0;
+ info_ptr->max_text = 0;
+ }
+ }
+#endif
+
+#ifdef PNG_tRNS_SUPPORTED
+ /* Free any tRNS entry */
+ if (((mask & PNG_FREE_TRNS) & info_ptr->free_me) != 0)
+ {
+ info_ptr->valid &= ~PNG_INFO_tRNS;
+ png_free(png_ptr, info_ptr->trans_alpha);
+ info_ptr->trans_alpha = NULL;
+ info_ptr->num_trans = 0;
+ }
+#endif
+
+#ifdef PNG_sCAL_SUPPORTED
+ /* Free any sCAL entry */
+ if (((mask & PNG_FREE_SCAL) & info_ptr->free_me) != 0)
+ {
+ png_free(png_ptr, info_ptr->scal_s_width);
+ png_free(png_ptr, info_ptr->scal_s_height);
+ info_ptr->scal_s_width = NULL;
+ info_ptr->scal_s_height = NULL;
+ info_ptr->valid &= ~PNG_INFO_sCAL;
+ }
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+ /* Free any pCAL entry */
+ if (((mask & PNG_FREE_PCAL) & info_ptr->free_me) != 0)
+ {
+ png_free(png_ptr, info_ptr->pcal_purpose);
+ png_free(png_ptr, info_ptr->pcal_units);
+ info_ptr->pcal_purpose = NULL;
+ info_ptr->pcal_units = NULL;
+
+ if (info_ptr->pcal_params != NULL)
+ {
+ int i;
+
+ for (i = 0; i < info_ptr->pcal_nparams; i++)
+ png_free(png_ptr, info_ptr->pcal_params[i]);
+
+ png_free(png_ptr, info_ptr->pcal_params);
+ info_ptr->pcal_params = NULL;
+ }
+ info_ptr->valid &= ~PNG_INFO_pCAL;
+ }
+#endif
+
+#ifdef PNG_iCCP_SUPPORTED
+ /* Free any profile entry */
+ if (((mask & PNG_FREE_ICCP) & info_ptr->free_me) != 0)
+ {
+ png_free(png_ptr, info_ptr->iccp_name);
+ png_free(png_ptr, info_ptr->iccp_profile);
+ info_ptr->iccp_name = NULL;
+ info_ptr->iccp_profile = NULL;
+ info_ptr->valid &= ~PNG_INFO_iCCP;
+ }
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+ /* Free a given sPLT entry, or (if num == -1) all sPLT entries */
+ if (info_ptr->splt_palettes != NULL &&
+ ((mask & PNG_FREE_SPLT) & info_ptr->free_me) != 0)
+ {
+ if (num != -1)
+ {
+ png_free(png_ptr, info_ptr->splt_palettes[num].name);
+ png_free(png_ptr, info_ptr->splt_palettes[num].entries);
+ info_ptr->splt_palettes[num].name = NULL;
+ info_ptr->splt_palettes[num].entries = NULL;
+ }
+
+ else
+ {
+ int i;
+
+ for (i = 0; i < info_ptr->splt_palettes_num; i++)
+ {
+ png_free(png_ptr, info_ptr->splt_palettes[i].name);
+ png_free(png_ptr, info_ptr->splt_palettes[i].entries);
+ }
+
+ png_free(png_ptr, info_ptr->splt_palettes);
+ info_ptr->splt_palettes = NULL;
+ info_ptr->splt_palettes_num = 0;
+ info_ptr->valid &= ~PNG_INFO_sPLT;
+ }
+ }
+#endif
+
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+ if (info_ptr->unknown_chunks != NULL &&
+ ((mask & PNG_FREE_UNKN) & info_ptr->free_me) != 0)
+ {
+ if (num != -1)
+ {
+ png_free(png_ptr, info_ptr->unknown_chunks[num].data);
+ info_ptr->unknown_chunks[num].data = NULL;
+ }
+
+ else
+ {
+ int i;
+
+ for (i = 0; i < info_ptr->unknown_chunks_num; i++)
+ png_free(png_ptr, info_ptr->unknown_chunks[i].data);
+
+ png_free(png_ptr, info_ptr->unknown_chunks);
+ info_ptr->unknown_chunks = NULL;
+ info_ptr->unknown_chunks_num = 0;
+ }
+ }
+#endif
+
+#ifdef PNG_eXIf_SUPPORTED
+ /* Free any eXIf entry */
+ if (((mask & PNG_FREE_EXIF) & info_ptr->free_me) != 0)
+ {
+ if (info_ptr->exif)
+ {
+ png_free(png_ptr, info_ptr->exif);
+ info_ptr->exif = NULL;
+ }
+ info_ptr->valid &= ~PNG_INFO_eXIf;
+ }
+#endif
+
+#ifdef PNG_hIST_SUPPORTED
+ /* Free any hIST entry */
+ if (((mask & PNG_FREE_HIST) & info_ptr->free_me) != 0)
+ {
+ png_free(png_ptr, info_ptr->hist);
+ info_ptr->hist = NULL;
+ info_ptr->valid &= ~PNG_INFO_hIST;
+ }
+#endif
+
+ /* Free any PLTE entry that was internally allocated */
+ if (((mask & PNG_FREE_PLTE) & info_ptr->free_me) != 0)
+ {
+ png_free(png_ptr, info_ptr->palette);
+ info_ptr->palette = NULL;
+ info_ptr->valid &= ~PNG_INFO_PLTE;
+ info_ptr->num_palette = 0;
+ }
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+ /* Free any image bits attached to the info structure */
+ if (((mask & PNG_FREE_ROWS) & info_ptr->free_me) != 0)
+ {
+ if (info_ptr->row_pointers != NULL)
+ {
+ png_uint_32 row;
+ for (row = 0; row < info_ptr->height; row++)
+ png_free(png_ptr, info_ptr->row_pointers[row]);
+
+ png_free(png_ptr, info_ptr->row_pointers);
+ info_ptr->row_pointers = NULL;
+ }
+ info_ptr->valid &= ~PNG_INFO_IDAT;
+ }
+#endif
+
+ if (num != -1)
+ mask &= ~PNG_FREE_MUL;
+
+ info_ptr->free_me &= ~mask;
+}
+#endif /* READ || WRITE */
+
+/* This function returns a pointer to the io_ptr associated with the user
+ * functions. The application should free any memory associated with this
+ * pointer before png_write_destroy() or png_read_destroy() are called.
+ */
+png_voidp PNGAPI
+png_get_io_ptr(png_const_structrp png_ptr)
+{
+ if (png_ptr == NULL)
+ return NULL;
+
+ return png_ptr->io_ptr;
+}
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+# ifdef PNG_STDIO_SUPPORTED
+/* Initialize the default input/output functions for the PNG file. If you
+ * use your own read or write routines, you can call either png_set_read_fn()
+ * or png_set_write_fn() instead of png_init_io(). If you have defined
+ * PNG_NO_STDIO or otherwise disabled PNG_STDIO_SUPPORTED, you must use a
+ * function of your own because "FILE *" isn't necessarily available.
+ */
+void PNGAPI
+png_init_io(png_structrp png_ptr, FILE *fp)
+{
+ png_debug(1, "in png_init_io");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->io_ptr = (png_voidp)fp;
+}
+# endif
+
+# ifdef PNG_SAVE_INT_32_SUPPORTED
+/* PNG signed integers are saved in 32-bit 2's complement format. ANSI C-90
+ * defines a cast of a signed integer to an unsigned integer either to preserve
+ * the value, if it is positive, or to calculate:
+ *
+ * (UNSIGNED_MAX+1) + integer
+ *
+ * Where UNSIGNED_MAX is the appropriate maximum unsigned value, so when the
+ * negative integral value is added the result will be an unsigned value
+ * corresponding to the 2's complement representation.
+ */
+void PNGAPI
+png_save_int_32(png_bytep buf, png_int_32 i)
+{
+ png_save_uint_32(buf, (png_uint_32)i);
+}
+# endif
+
+# ifdef PNG_TIME_RFC1123_SUPPORTED
+/* Convert the supplied time into an RFC 1123 string suitable for use in
+ * a "Creation Time" or other text-based time string.
+ */
+int PNGAPI
+png_convert_to_rfc1123_buffer(char out[29], png_const_timep ptime)
+{
+ static const char short_months[12][4] =
+ {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
+ "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
+
+ if (out == NULL)
+ return 0;
+
+ if (ptime->year > 9999 /* RFC1123 limitation */ ||
+ ptime->month == 0 || ptime->month > 12 ||
+ ptime->day == 0 || ptime->day > 31 ||
+ ptime->hour > 23 || ptime->minute > 59 ||
+ ptime->second > 60)
+ return 0;
+
+ {
+ size_t pos = 0;
+ char number_buf[5] = {0, 0, 0, 0, 0}; /* enough for a four-digit year */
+
+# define APPEND_STRING(string) pos = png_safecat(out, 29, pos, (string))
+# define APPEND_NUMBER(format, value)\
+ APPEND_STRING(PNG_FORMAT_NUMBER(number_buf, format, (value)))
+# define APPEND(ch) if (pos < 28) out[pos++] = (ch)
+
+ APPEND_NUMBER(PNG_NUMBER_FORMAT_u, (unsigned)ptime->day);
+ APPEND(' ');
+ APPEND_STRING(short_months[(ptime->month - 1)]);
+ APPEND(' ');
+ APPEND_NUMBER(PNG_NUMBER_FORMAT_u, ptime->year);
+ APPEND(' ');
+ APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->hour);
+ APPEND(':');
+ APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->minute);
+ APPEND(':');
+ APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->second);
+ APPEND_STRING(" +0000"); /* This reliably terminates the buffer */
+ PNG_UNUSED (pos)
+
+# undef APPEND
+# undef APPEND_NUMBER
+# undef APPEND_STRING
+ }
+
+ return 1;
+}
+
+# if PNG_LIBPNG_VER < 10700
+/* To do: remove the following from libpng-1.7 */
+/* Original API that uses a private buffer in png_struct.
+ * Deprecated because it causes png_struct to carry a spurious temporary
+ * buffer (png_struct::time_buffer), better to have the caller pass this in.
+ */
+png_const_charp PNGAPI
+png_convert_to_rfc1123(png_structrp png_ptr, png_const_timep ptime)
+{
+ if (png_ptr != NULL)
+ {
+ /* The only failure above if png_ptr != NULL is from an invalid ptime */
+ if (png_convert_to_rfc1123_buffer(png_ptr->time_buffer, ptime) == 0)
+ png_warning(png_ptr, "Ignoring invalid time value");
+
+ else
+ return png_ptr->time_buffer;
+ }
+
+ return NULL;
+}
+# endif /* LIBPNG_VER < 10700 */
+# endif /* TIME_RFC1123 */
+
+#endif /* READ || WRITE */
+
+png_const_charp PNGAPI
+png_get_copyright(png_const_structrp png_ptr)
+{
+ PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */
+#ifdef PNG_STRING_COPYRIGHT
+ return PNG_STRING_COPYRIGHT
+#else
+ return PNG_STRING_NEWLINE \
+ "libpng version 1.6.49.git" PNG_STRING_NEWLINE \
+ "Copyright (c) 2018-2025 Cosmin Truta" PNG_STRING_NEWLINE \
+ "Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson" \
+ PNG_STRING_NEWLINE \
+ "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
+ "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
+ PNG_STRING_NEWLINE;
+#endif
+}
+
+/* The following return the library version as a short string in the
+ * format 1.0.0 through 99.99.99zz. To get the version of *.h files
+ * used with your application, print out PNG_LIBPNG_VER_STRING, which
+ * is defined in png.h.
+ * Note: now there is no difference between png_get_libpng_ver() and
+ * png_get_header_ver(). Due to the version_nn_nn_nn typedef guard,
+ * it is guaranteed that png.c uses the correct version of png.h.
+ */
+png_const_charp PNGAPI
+png_get_libpng_ver(png_const_structrp png_ptr)
+{
+ /* Version of *.c files used when building libpng */
+ return png_get_header_ver(png_ptr);
+}
+
+png_const_charp PNGAPI
+png_get_header_ver(png_const_structrp png_ptr)
+{
+ /* Version of *.h files used when building libpng */
+ PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */
+ return PNG_LIBPNG_VER_STRING;
+}
+
+png_const_charp PNGAPI
+png_get_header_version(png_const_structrp png_ptr)
+{
+ /* Returns longer string containing both version and date */
+ PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */
+#ifdef __STDC__
+ return PNG_HEADER_VERSION_STRING
+# ifndef PNG_READ_SUPPORTED
+ " (NO READ SUPPORT)"
+# endif
+ PNG_STRING_NEWLINE;
+#else
+ return PNG_HEADER_VERSION_STRING;
+#endif
+}
+
+#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
+/* NOTE: this routine is not used internally! */
+/* Build a grayscale palette. Palette is assumed to be 1 << bit_depth
+ * large of png_color. This lets grayscale images be treated as
+ * paletted. Most useful for gamma correction and simplification
+ * of code. This API is not used internally.
+ */
+void PNGAPI
+png_build_grayscale_palette(int bit_depth, png_colorp palette)
+{
+ int num_palette;
+ int color_inc;
+ int i;
+ int v;
+
+ png_debug(1, "in png_do_build_grayscale_palette");
+
+ if (palette == NULL)
+ return;
+
+ switch (bit_depth)
+ {
+ case 1:
+ num_palette = 2;
+ color_inc = 0xff;
+ break;
+
+ case 2:
+ num_palette = 4;
+ color_inc = 0x55;
+ break;
+
+ case 4:
+ num_palette = 16;
+ color_inc = 0x11;
+ break;
+
+ case 8:
+ num_palette = 256;
+ color_inc = 1;
+ break;
+
+ default:
+ num_palette = 0;
+ color_inc = 0;
+ break;
+ }
+
+ for (i = 0, v = 0; i < num_palette; i++, v += color_inc)
+ {
+ palette[i].red = (png_byte)(v & 0xff);
+ palette[i].green = (png_byte)(v & 0xff);
+ palette[i].blue = (png_byte)(v & 0xff);
+ }
+}
+#endif
+
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+int PNGAPI
+png_handle_as_unknown(png_const_structrp png_ptr, png_const_bytep chunk_name)
+{
+ /* Check chunk_name and return "keep" value if it's on the list, else 0 */
+ png_const_bytep p, p_end;
+
+ if (png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list == 0)
+ return PNG_HANDLE_CHUNK_AS_DEFAULT;
+
+ p_end = png_ptr->chunk_list;
+ p = p_end + png_ptr->num_chunk_list*5; /* beyond end */
+
+ /* The code is the fifth byte after each four byte string. Historically this
+ * code was always searched from the end of the list, this is no longer
+ * necessary because the 'set' routine handles duplicate entries correctly.
+ */
+ do /* num_chunk_list > 0, so at least one */
+ {
+ p -= 5;
+
+ if (memcmp(chunk_name, p, 4) == 0)
+ return p[4];
+ }
+ while (p > p_end);
+
+ /* This means that known chunks should be processed and unknown chunks should
+ * be handled according to the value of png_ptr->unknown_default; this can be
+ * confusing because, as a result, there are two levels of defaulting for
+ * unknown chunks.
+ */
+ return PNG_HANDLE_CHUNK_AS_DEFAULT;
+}
+
+#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\
+ defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
+int /* PRIVATE */
+png_chunk_unknown_handling(png_const_structrp png_ptr, png_uint_32 chunk_name)
+{
+ png_byte chunk_string[5];
+
+ PNG_CSTRING_FROM_CHUNK(chunk_string, chunk_name);
+ return png_handle_as_unknown(png_ptr, chunk_string);
+}
+#endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */
+#endif /* SET_UNKNOWN_CHUNKS */
+
+#ifdef PNG_READ_SUPPORTED
+/* This function, added to libpng-1.0.6g, is untested. */
+int PNGAPI
+png_reset_zstream(png_structrp png_ptr)
+{
+ if (png_ptr == NULL)
+ return Z_STREAM_ERROR;
+
+ /* WARNING: this resets the window bits to the maximum! */
+ return inflateReset(&png_ptr->zstream);
+}
+#endif /* READ */
+
+/* This function was added to libpng-1.0.7 */
+png_uint_32 PNGAPI
+png_access_version_number(void)
+{
+ /* Version of *.c files used when building libpng */
+ return (png_uint_32)PNG_LIBPNG_VER;
+}
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+/* Ensure that png_ptr->zstream.msg holds some appropriate error message string.
+ * If it doesn't 'ret' is used to set it to something appropriate, even in cases
+ * like Z_OK or Z_STREAM_END where the error code is apparently a success code.
+ */
+void /* PRIVATE */
+png_zstream_error(png_structrp png_ptr, int ret)
+{
+ /* Translate 'ret' into an appropriate error string, priority is given to the
+ * one in zstream if set. This always returns a string, even in cases like
+ * Z_OK or Z_STREAM_END where the error code is a success code.
+ */
+ if (png_ptr->zstream.msg == NULL) switch (ret)
+ {
+ default:
+ case Z_OK:
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("unexpected zlib return code");
+ break;
+
+ case Z_STREAM_END:
+ /* Normal exit */
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("unexpected end of LZ stream");
+ break;
+
+ case Z_NEED_DICT:
+ /* This means the deflate stream did not have a dictionary; this
+ * indicates a bogus PNG.
+ */
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("missing LZ dictionary");
+ break;
+
+ case Z_ERRNO:
+ /* gz APIs only: should not happen */
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("zlib IO error");
+ break;
+
+ case Z_STREAM_ERROR:
+ /* internal libpng error */
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("bad parameters to zlib");
+ break;
+
+ case Z_DATA_ERROR:
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("damaged LZ stream");
+ break;
+
+ case Z_MEM_ERROR:
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("insufficient memory");
+ break;
+
+ case Z_BUF_ERROR:
+ /* End of input or output; not a problem if the caller is doing
+ * incremental read or write.
+ */
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("truncated");
+ break;
+
+ case Z_VERSION_ERROR:
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("unsupported zlib version");
+ break;
+
+ case PNG_UNEXPECTED_ZLIB_RETURN:
+ /* Compile errors here mean that zlib now uses the value co-opted in
+ * pngpriv.h for PNG_UNEXPECTED_ZLIB_RETURN; update the switch above
+ * and change pngpriv.h. Note that this message is "... return",
+ * whereas the default/Z_OK one is "... return code".
+ */
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("unexpected zlib return");
+ break;
+ }
+}
+
+#ifdef PNG_COLORSPACE_SUPPORTED
+static png_int_32
+png_fp_add(png_int_32 addend0, png_int_32 addend1, int *error)
+{
+ /* Safely add two fixed point values setting an error flag and returning 0.5
+ * on overflow.
+ * IMPLEMENTATION NOTE: ANSI requires signed overflow not to occur, therefore
+ * relying on addition of two positive values producing a negative one is not
+ * safe.
+ */
+ if (addend0 > 0)
+ {
+ if (0x7fffffff - addend0 >= addend1)
+ return addend0+addend1;
+ }
+ else if (addend0 < 0)
+ {
+ if (-0x7fffffff - addend0 <= addend1)
+ return addend0+addend1;
+ }
+ else
+ return addend1;
+
+ *error = 1;
+ return PNG_FP_1/2;
+}
+
+static png_int_32
+png_fp_sub(png_int_32 addend0, png_int_32 addend1, int *error)
+{
+ /* As above but calculate addend0-addend1. */
+ if (addend1 > 0)
+ {
+ if (-0x7fffffff + addend1 <= addend0)
+ return addend0-addend1;
+ }
+ else if (addend1 < 0)
+ {
+ if (0x7fffffff + addend1 >= addend0)
+ return addend0-addend1;
+ }
+ else
+ return addend0;
+
+ *error = 1;
+ return PNG_FP_1/2;
+}
+
+static int
+png_safe_add(png_int_32 *addend0_and_result, png_int_32 addend1,
+ png_int_32 addend2)
+{
+ /* Safely add three integers. Returns 0 on success, 1 on overflow. Does not
+ * set the result on overflow.
+ */
+ int error = 0;
+ int result = png_fp_add(*addend0_and_result,
+ png_fp_add(addend1, addend2, &error),
+ &error);
+ if (!error) *addend0_and_result = result;
+ return error;
+}
+
+/* Added at libpng-1.5.5 to support read and write of true CIEXYZ values for
+ * cHRM, as opposed to using chromaticities. These internal APIs return
+ * non-zero on a parameter error. The X, Y and Z values are required to be
+ * positive and less than 1.0.
+ */
+int /* PRIVATE */
+png_xy_from_XYZ(png_xy *xy, const png_XYZ *XYZ)
+{
+ /* NOTE: returns 0 on success, 1 means error. */
+ png_int_32 d, dred, dgreen, dblue, dwhite, whiteX, whiteY;
+
+ /* 'd' in each of the blocks below is just X+Y+Z for each component,
+ * x, y and z are X,Y,Z/(X+Y+Z).
+ */
+ d = XYZ->red_X;
+ if (png_safe_add(&d, XYZ->red_Y, XYZ->red_Z))
+ return 1;
+ dred = d;
+ if (png_muldiv(&xy->redx, XYZ->red_X, PNG_FP_1, dred) == 0)
+ return 1;
+ if (png_muldiv(&xy->redy, XYZ->red_Y, PNG_FP_1, dred) == 0)
+ return 1;
+
+ d = XYZ->green_X;
+ if (png_safe_add(&d, XYZ->green_Y, XYZ->green_Z))
+ return 1;
+ dgreen = d;
+ if (png_muldiv(&xy->greenx, XYZ->green_X, PNG_FP_1, dgreen) == 0)
+ return 1;
+ if (png_muldiv(&xy->greeny, XYZ->green_Y, PNG_FP_1, dgreen) == 0)
+ return 1;
+
+ d = XYZ->blue_X;
+ if (png_safe_add(&d, XYZ->blue_Y, XYZ->blue_Z))
+ return 1;
+ dblue = d;
+ if (png_muldiv(&xy->bluex, XYZ->blue_X, PNG_FP_1, dblue) == 0)
+ return 1;
+ if (png_muldiv(&xy->bluey, XYZ->blue_Y, PNG_FP_1, dblue) == 0)
+ return 1;
+
+ /* The reference white is simply the sum of the end-point (X,Y,Z) vectors so
+ * the fillowing calculates (X+Y+Z) of the reference white (media white,
+ * encoding white) itself:
+ */
+ d = dblue;
+ if (png_safe_add(&d, dred, dgreen))
+ return 1;
+ dwhite = d;
+
+ /* Find the white X,Y values from the sum of the red, green and blue X,Y
+ * values.
+ */
+ d = XYZ->red_X;
+ if (png_safe_add(&d, XYZ->green_X, XYZ->blue_X))
+ return 1;
+ whiteX = d;
+
+ d = XYZ->red_Y;
+ if (png_safe_add(&d, XYZ->green_Y, XYZ->blue_Y))
+ return 1;
+ whiteY = d;
+
+ if (png_muldiv(&xy->whitex, whiteX, PNG_FP_1, dwhite) == 0)
+ return 1;
+ if (png_muldiv(&xy->whitey, whiteY, PNG_FP_1, dwhite) == 0)
+ return 1;
+
+ return 0;
+}
+
+int /* PRIVATE */
+png_XYZ_from_xy(png_XYZ *XYZ, const png_xy *xy)
+{
+ /* NOTE: returns 0 on success, 1 means error. */
+ png_fixed_point red_inverse, green_inverse, blue_scale;
+ png_fixed_point left, right, denominator;
+
+ /* Check xy and, implicitly, z. Note that wide gamut color spaces typically
+ * have end points with 0 tristimulus values (these are impossible end
+ * points, but they are used to cover the possible colors). We check
+ * xy->whitey against 5, not 0, to avoid a possible integer overflow.
+ *
+ * The limits here will *not* accept ACES AP0, where bluey is -7700
+ * (-0.0770) because the PNG spec itself requires the xy values to be
+ * unsigned. whitey is also required to be 5 or more to avoid overflow.
+ *
+ * Instead the upper limits have been relaxed to accomodate ACES AP1 where
+ * redz ends up as -600 (-0.006). ProPhotoRGB was already "in range."
+ * The new limit accomodates the AP0 and AP1 ranges for z but not AP0 redy.
+ */
+ const png_fixed_point fpLimit = PNG_FP_1+(PNG_FP_1/10);
+ if (xy->redx < 0 || xy->redx > fpLimit) return 1;
+ if (xy->redy < 0 || xy->redy > fpLimit-xy->redx) return 1;
+ if (xy->greenx < 0 || xy->greenx > fpLimit) return 1;
+ if (xy->greeny < 0 || xy->greeny > fpLimit-xy->greenx) return 1;
+ if (xy->bluex < 0 || xy->bluex > fpLimit) return 1;
+ if (xy->bluey < 0 || xy->bluey > fpLimit-xy->bluex) return 1;
+ if (xy->whitex < 0 || xy->whitex > fpLimit) return 1;
+ if (xy->whitey < 5 || xy->whitey > fpLimit-xy->whitex) return 1;
+
+ /* The reverse calculation is more difficult because the original tristimulus
+ * value had 9 independent values (red,green,blue)x(X,Y,Z) however only 8
+ * derived values were recorded in the cHRM chunk;
+ * (red,green,blue,white)x(x,y). This loses one degree of freedom and
+ * therefore an arbitrary ninth value has to be introduced to undo the
+ * original transformations.
+ *
+ * Think of the original end-points as points in (X,Y,Z) space. The
+ * chromaticity values (c) have the property:
+ *
+ * C
+ * c = ---------
+ * X + Y + Z
+ *
+ * For each c (x,y,z) from the corresponding original C (X,Y,Z). Thus the
+ * three chromaticity values (x,y,z) for each end-point obey the
+ * relationship:
+ *
+ * x + y + z = 1
+ *
+ * This describes the plane in (X,Y,Z) space that intersects each axis at the
+ * value 1.0; call this the chromaticity plane. Thus the chromaticity
+ * calculation has scaled each end-point so that it is on the x+y+z=1 plane
+ * and chromaticity is the intersection of the vector from the origin to the
+ * (X,Y,Z) value with the chromaticity plane.
+ *
+ * To fully invert the chromaticity calculation we would need the three
+ * end-point scale factors, (red-scale, green-scale, blue-scale), but these
+ * were not recorded. Instead we calculated the reference white (X,Y,Z) and
+ * recorded the chromaticity of this. The reference white (X,Y,Z) would have
+ * given all three of the scale factors since:
+ *
+ * color-C = color-c * color-scale
+ * white-C = red-C + green-C + blue-C
+ * = red-c*red-scale + green-c*green-scale + blue-c*blue-scale
+ *
+ * But cHRM records only white-x and white-y, so we have lost the white scale
+ * factor:
+ *
+ * white-C = white-c*white-scale
+ *
+ * To handle this the inverse transformation makes an arbitrary assumption
+ * about white-scale:
+ *
+ * Assume: white-Y = 1.0
+ * Hence: white-scale = 1/white-y
+ * Or: red-Y + green-Y + blue-Y = 1.0
+ *
+ * Notice the last statement of the assumption gives an equation in three of
+ * the nine values we want to calculate. 8 more equations come from the
+ * above routine as summarised at the top above (the chromaticity
+ * calculation):
+ *
+ * Given: color-x = color-X / (color-X + color-Y + color-Z)
+ * Hence: (color-x - 1)*color-X + color.x*color-Y + color.x*color-Z = 0
+ *
+ * This is 9 simultaneous equations in the 9 variables "color-C" and can be
+ * solved by Cramer's rule. Cramer's rule requires calculating 10 9x9 matrix
+ * determinants, however this is not as bad as it seems because only 28 of
+ * the total of 90 terms in the various matrices are non-zero. Nevertheless
+ * Cramer's rule is notoriously numerically unstable because the determinant
+ * calculation involves the difference of large, but similar, numbers. It is
+ * difficult to be sure that the calculation is stable for real world values
+ * and it is certain that it becomes unstable where the end points are close
+ * together.
+ *
+ * So this code uses the perhaps slightly less optimal but more
+ * understandable and totally obvious approach of calculating color-scale.
+ *
+ * This algorithm depends on the precision in white-scale and that is
+ * (1/white-y), so we can immediately see that as white-y approaches 0 the
+ * accuracy inherent in the cHRM chunk drops off substantially.
+ *
+ * libpng arithmetic: a simple inversion of the above equations
+ * ------------------------------------------------------------
+ *
+ * white_scale = 1/white-y
+ * white-X = white-x * white-scale
+ * white-Y = 1.0
+ * white-Z = (1 - white-x - white-y) * white_scale
+ *
+ * white-C = red-C + green-C + blue-C
+ * = red-c*red-scale + green-c*green-scale + blue-c*blue-scale
+ *
+ * This gives us three equations in (red-scale,green-scale,blue-scale) where
+ * all the coefficients are now known:
+ *
+ * red-x*red-scale + green-x*green-scale + blue-x*blue-scale
+ * = white-x/white-y
+ * red-y*red-scale + green-y*green-scale + blue-y*blue-scale = 1
+ * red-z*red-scale + green-z*green-scale + blue-z*blue-scale
+ * = (1 - white-x - white-y)/white-y
+ *
+ * In the last equation color-z is (1 - color-x - color-y) so we can add all
+ * three equations together to get an alternative third:
+ *
+ * red-scale + green-scale + blue-scale = 1/white-y = white-scale
+ *
+ * So now we have a Cramer's rule solution where the determinants are just
+ * 3x3 - far more tractible. Unfortunately 3x3 determinants still involve
+ * multiplication of three coefficients so we can't guarantee to avoid
+ * overflow in the libpng fixed point representation. Using Cramer's rule in
+ * floating point is probably a good choice here, but it's not an option for
+ * fixed point. Instead proceed to simplify the first two equations by
+ * eliminating what is likely to be the largest value, blue-scale:
+ *
+ * blue-scale = white-scale - red-scale - green-scale
+ *
+ * Hence:
+ *
+ * (red-x - blue-x)*red-scale + (green-x - blue-x)*green-scale =
+ * (white-x - blue-x)*white-scale
+ *
+ * (red-y - blue-y)*red-scale + (green-y - blue-y)*green-scale =
+ * 1 - blue-y*white-scale
+ *
+ * And now we can trivially solve for (red-scale,green-scale):
+ *
+ * green-scale =
+ * (white-x - blue-x)*white-scale - (red-x - blue-x)*red-scale
+ * -----------------------------------------------------------
+ * green-x - blue-x
+ *
+ * red-scale =
+ * 1 - blue-y*white-scale - (green-y - blue-y) * green-scale
+ * ---------------------------------------------------------
+ * red-y - blue-y
+ *
+ * Hence:
+ *
+ * red-scale =
+ * ( (green-x - blue-x) * (white-y - blue-y) -
+ * (green-y - blue-y) * (white-x - blue-x) ) / white-y
+ * -------------------------------------------------------------------------
+ * (green-x - blue-x)*(red-y - blue-y)-(green-y - blue-y)*(red-x - blue-x)
+ *
+ * green-scale =
+ * ( (red-y - blue-y) * (white-x - blue-x) -
+ * (red-x - blue-x) * (white-y - blue-y) ) / white-y
+ * -------------------------------------------------------------------------
+ * (green-x - blue-x)*(red-y - blue-y)-(green-y - blue-y)*(red-x - blue-x)
+ *
+ * Accuracy:
+ * The input values have 5 decimal digits of accuracy.
+ *
+ * In the previous implementation the values were all in the range 0 < value
+ * < 1, so simple products are in the same range but may need up to 10
+ * decimal digits to preserve the original precision and avoid underflow.
+ * Because we are using a 32-bit signed representation we cannot match this;
+ * the best is a little over 9 decimal digits, less than 10.
+ *
+ * This range has now been extended to allow values up to 1.1, or 110,000 in
+ * fixed point.
+ *
+ * The approach used here is to preserve the maximum precision within the
+ * signed representation. Because the red-scale calculation above uses the
+ * difference between two products of values that must be in the range
+ * -1.1..+1.1 it is sufficient to divide the product by 8;
+ * ceil(121,000/32767*2). The factor is irrelevant in the calculation
+ * because it is applied to both numerator and denominator.
+ *
+ * Note that the values of the differences of the products of the
+ * chromaticities in the above equations tend to be small, for example for
+ * the sRGB chromaticities they are:
+ *
+ * red numerator: -0.04751
+ * green numerator: -0.08788
+ * denominator: -0.2241 (without white-y multiplication)
+ *
+ * The resultant Y coefficients from the chromaticities of some widely used
+ * color space definitions are (to 15 decimal places):
+ *
+ * sRGB
+ * 0.212639005871510 0.715168678767756 0.072192315360734
+ * Kodak ProPhoto
+ * 0.288071128229293 0.711843217810102 0.000085653960605
+ * Adobe RGB
+ * 0.297344975250536 0.627363566255466 0.075291458493998
+ * Adobe Wide Gamut RGB
+ * 0.258728243040113 0.724682314948566 0.016589442011321
+ */
+ {
+ int error = 0;
+
+ /* By the argument above overflow should be impossible here, however the
+ * code now simply returns a failure code. The xy subtracts in the
+ * arguments to png_muldiv are *not* checked for overflow because the
+ * checks at the start guarantee they are in the range 0..110000 and
+ * png_fixed_point is a 32-bit signed number.
+ */
+ if (png_muldiv(&left, xy->greenx-xy->bluex, xy->redy - xy->bluey, 8) == 0)
+ return 1;
+ if (png_muldiv(&right, xy->greeny-xy->bluey, xy->redx - xy->bluex, 8) ==
+ 0)
+ return 1;
+ denominator = png_fp_sub(left, right, &error);
+ if (error) return 1;
+
+ /* Now find the red numerator. */
+ if (png_muldiv(&left, xy->greenx-xy->bluex, xy->whitey-xy->bluey, 8) == 0)
+ return 1;
+ if (png_muldiv(&right, xy->greeny-xy->bluey, xy->whitex-xy->bluex, 8) ==
+ 0)
+ return 1;
+
+ /* Overflow is possible here and it indicates an extreme set of PNG cHRM
+ * chunk values. This calculation actually returns the reciprocal of the
+ * scale value because this allows us to delay the multiplication of
+ * white-y into the denominator, which tends to produce a small number.
+ */
+ if (png_muldiv(&red_inverse, xy->whitey, denominator,
+ png_fp_sub(left, right, &error)) == 0 || error ||
+ red_inverse <= xy->whitey /* r+g+b scales = white scale */)
+ return 1;
+
+ /* Similarly for green_inverse: */
+ if (png_muldiv(&left, xy->redy-xy->bluey, xy->whitex-xy->bluex, 8) == 0)
+ return 1;
+ if (png_muldiv(&right, xy->redx-xy->bluex, xy->whitey-xy->bluey, 8) == 0)
+ return 1;
+ if (png_muldiv(&green_inverse, xy->whitey, denominator,
+ png_fp_sub(left, right, &error)) == 0 || error ||
+ green_inverse <= xy->whitey)
+ return 1;
+
+ /* And the blue scale, the checks above guarantee this can't overflow but
+ * it can still produce 0 for extreme cHRM values.
+ */
+ blue_scale = png_fp_sub(png_fp_sub(png_reciprocal(xy->whitey),
+ png_reciprocal(red_inverse), &error),
+ png_reciprocal(green_inverse), &error);
+ if (error || blue_scale <= 0)
+ return 1;
+ }
+
+ /* And fill in the png_XYZ. Again the subtracts are safe because of the
+ * checks on the xy values at the start (the subtracts just calculate the
+ * corresponding z values.)
+ */
+ if (png_muldiv(&XYZ->red_X, xy->redx, PNG_FP_1, red_inverse) == 0)
+ return 1;
+ if (png_muldiv(&XYZ->red_Y, xy->redy, PNG_FP_1, red_inverse) == 0)
+ return 1;
+ if (png_muldiv(&XYZ->red_Z, PNG_FP_1 - xy->redx - xy->redy, PNG_FP_1,
+ red_inverse) == 0)
+ return 1;
+
+ if (png_muldiv(&XYZ->green_X, xy->greenx, PNG_FP_1, green_inverse) == 0)
+ return 1;
+ if (png_muldiv(&XYZ->green_Y, xy->greeny, PNG_FP_1, green_inverse) == 0)
+ return 1;
+ if (png_muldiv(&XYZ->green_Z, PNG_FP_1 - xy->greenx - xy->greeny, PNG_FP_1,
+ green_inverse) == 0)
+ return 1;
+
+ if (png_muldiv(&XYZ->blue_X, xy->bluex, blue_scale, PNG_FP_1) == 0)
+ return 1;
+ if (png_muldiv(&XYZ->blue_Y, xy->bluey, blue_scale, PNG_FP_1) == 0)
+ return 1;
+ if (png_muldiv(&XYZ->blue_Z, PNG_FP_1 - xy->bluex - xy->bluey, blue_scale,
+ PNG_FP_1) == 0)
+ return 1;
+
+ return 0; /*success*/
+}
+#endif /* COLORSPACE */
+
+#ifdef PNG_READ_iCCP_SUPPORTED
+/* Error message generation */
+static char
+png_icc_tag_char(png_uint_32 byte)
+{
+ byte &= 0xff;
+ if (byte >= 32 && byte <= 126)
+ return (char)byte;
+ else
+ return '?';
+}
+
+static void
+png_icc_tag_name(char *name, png_uint_32 tag)
+{
+ name[0] = '\'';
+ name[1] = png_icc_tag_char(tag >> 24);
+ name[2] = png_icc_tag_char(tag >> 16);
+ name[3] = png_icc_tag_char(tag >> 8);
+ name[4] = png_icc_tag_char(tag );
+ name[5] = '\'';
+}
+
+static int
+is_ICC_signature_char(png_alloc_size_t it)
+{
+ return it == 32 || (it >= 48 && it <= 57) || (it >= 65 && it <= 90) ||
+ (it >= 97 && it <= 122);
+}
+
+static int
+is_ICC_signature(png_alloc_size_t it)
+{
+ return is_ICC_signature_char(it >> 24) /* checks all the top bits */ &&
+ is_ICC_signature_char((it >> 16) & 0xff) &&
+ is_ICC_signature_char((it >> 8) & 0xff) &&
+ is_ICC_signature_char(it & 0xff);
+}
+
+static int
+png_icc_profile_error(png_const_structrp png_ptr, png_const_charp name,
+ png_alloc_size_t value, png_const_charp reason)
+{
+ size_t pos;
+ char message[196]; /* see below for calculation */
+
+ pos = png_safecat(message, (sizeof message), 0, "profile '"); /* 9 chars */
+ pos = png_safecat(message, pos+79, pos, name); /* Truncate to 79 chars */
+ pos = png_safecat(message, (sizeof message), pos, "': "); /* +2 = 90 */
+ if (is_ICC_signature(value) != 0)
+ {
+ /* So 'value' is at most 4 bytes and the following cast is safe */
+ png_icc_tag_name(message+pos, (png_uint_32)value);
+ pos += 6; /* total +8; less than the else clause */
+ message[pos++] = ':';
+ message[pos++] = ' ';
+ }
+# ifdef PNG_WARNINGS_SUPPORTED
+ else
+ {
+ char number[PNG_NUMBER_BUFFER_SIZE]; /* +24 = 114 */
+
+ pos = png_safecat(message, (sizeof message), pos,
+ png_format_number(number, number+(sizeof number),
+ PNG_NUMBER_FORMAT_x, value));
+ pos = png_safecat(message, (sizeof message), pos, "h: "); /* +2 = 116 */
+ }
+# endif
+ /* The 'reason' is an arbitrary message, allow +79 maximum 195 */
+ pos = png_safecat(message, (sizeof message), pos, reason);
+ PNG_UNUSED(pos)
+
+ png_chunk_benign_error(png_ptr, message);
+
+ return 0;
+}
+
+/* Encoded value of D50 as an ICC XYZNumber. From the ICC 2010 spec the value
+ * is XYZ(0.9642,1.0,0.8249), which scales to:
+ *
+ * (63189.8112, 65536, 54060.6464)
+ */
+static const png_byte D50_nCIEXYZ[12] =
+ { 0x00, 0x00, 0xf6, 0xd6, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0xd3, 0x2d };
+
+static int /* bool */
+icc_check_length(png_const_structrp png_ptr, png_const_charp name,
+ png_uint_32 profile_length)
+{
+ if (profile_length < 132)
+ return png_icc_profile_error(png_ptr, name, profile_length, "too short");
+ return 1;
+}
+
+int /* PRIVATE */
+png_icc_check_length(png_const_structrp png_ptr, png_const_charp name,
+ png_uint_32 profile_length)
+{
+ if (!icc_check_length(png_ptr, name, profile_length))
+ return 0;
+
+ /* This needs to be here because the 'normal' check is in
+ * png_decompress_chunk, yet this happens after the attempt to
+ * png_malloc_base the required data. We only need this on read; on write
+ * the caller supplies the profile buffer so libpng doesn't allocate it. See
+ * the call to icc_check_length below (the write case).
+ */
+ if (profile_length > png_chunk_max(png_ptr))
+ return png_icc_profile_error(png_ptr, name, profile_length,
+ "profile too long");
+
+ return 1;
+}
+
+int /* PRIVATE */
+png_icc_check_header(png_const_structrp png_ptr, png_const_charp name,
+ png_uint_32 profile_length,
+ png_const_bytep profile/* first 132 bytes only */, int color_type)
+{
+ png_uint_32 temp;
+
+ /* Length check; this cannot be ignored in this code because profile_length
+ * is used later to check the tag table, so even if the profile seems over
+ * long profile_length from the caller must be correct. The caller can fix
+ * this up on read or write by just passing in the profile header length.
+ */
+ temp = png_get_uint_32(profile);
+ if (temp != profile_length)
+ return png_icc_profile_error(png_ptr, name, temp,
+ "length does not match profile");
+
+ temp = (png_uint_32) (*(profile+8));
+ if (temp > 3 && (profile_length & 3))
+ return png_icc_profile_error(png_ptr, name, profile_length,
+ "invalid length");
+
+ temp = png_get_uint_32(profile+128); /* tag count: 12 bytes/tag */
+ if (temp > 357913930 || /* (2^32-4-132)/12: maximum possible tag count */
+ profile_length < 132+12*temp) /* truncated tag table */
+ return png_icc_profile_error(png_ptr, name, temp,
+ "tag count too large");
+
+ /* The 'intent' must be valid or we can't store it, ICC limits the intent to
+ * 16 bits.
+ */
+ temp = png_get_uint_32(profile+64);
+ if (temp >= 0xffff) /* The ICC limit */
+ return png_icc_profile_error(png_ptr, name, temp,
+ "invalid rendering intent");
+
+ /* This is just a warning because the profile may be valid in future
+ * versions.
+ */
+ if (temp >= PNG_sRGB_INTENT_LAST)
+ (void)png_icc_profile_error(png_ptr, name, temp,
+ "intent outside defined range");
+
+ /* At this point the tag table can't be checked because it hasn't necessarily
+ * been loaded; however, various header fields can be checked. These checks
+ * are for values permitted by the PNG spec in an ICC profile; the PNG spec
+ * restricts the profiles that can be passed in an iCCP chunk (they must be
+ * appropriate to processing PNG data!)
+ */
+
+ /* Data checks (could be skipped). These checks must be independent of the
+ * version number; however, the version number doesn't accommodate changes in
+ * the header fields (just the known tags and the interpretation of the
+ * data.)
+ */
+ temp = png_get_uint_32(profile+36); /* signature 'ascp' */
+ if (temp != 0x61637370)
+ return png_icc_profile_error(png_ptr, name, temp,
+ "invalid signature");
+
+ /* Currently the PCS illuminant/adopted white point (the computational
+ * white point) are required to be D50,
+ * however the profile contains a record of the illuminant so perhaps ICC
+ * expects to be able to change this in the future (despite the rationale in
+ * the introduction for using a fixed PCS adopted white.) Consequently the
+ * following is just a warning.
+ */
+ if (memcmp(profile+68, D50_nCIEXYZ, 12) != 0)
+ (void)png_icc_profile_error(png_ptr, name, 0/*no tag value*/,
+ "PCS illuminant is not D50");
+
+ /* The PNG spec requires this:
+ * "If the iCCP chunk is present, the image samples conform to the colour
+ * space represented by the embedded ICC profile as defined by the
+ * International Color Consortium [ICC]. The colour space of the ICC profile
+ * shall be an RGB colour space for colour images (PNG colour types 2, 3, and
+ * 6), or a greyscale colour space for greyscale images (PNG colour types 0
+ * and 4)."
+ *
+ * This checking code ensures the embedded profile (on either read or write)
+ * conforms to the specification requirements. Notice that an ICC 'gray'
+ * color-space profile contains the information to transform the monochrome
+ * data to XYZ or L*a*b (according to which PCS the profile uses) and this
+ * should be used in preference to the standard libpng K channel replication
+ * into R, G and B channels.
+ *
+ * Previously it was suggested that an RGB profile on grayscale data could be
+ * handled. However it it is clear that using an RGB profile in this context
+ * must be an error - there is no specification of what it means. Thus it is
+ * almost certainly more correct to ignore the profile.
+ */
+ temp = png_get_uint_32(profile+16); /* data colour space field */
+ switch (temp)
+ {
+ case 0x52474220: /* 'RGB ' */
+ if ((color_type & PNG_COLOR_MASK_COLOR) == 0)
+ return png_icc_profile_error(png_ptr, name, temp,
+ "RGB color space not permitted on grayscale PNG");
+ break;
+
+ case 0x47524159: /* 'GRAY' */
+ if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
+ return png_icc_profile_error(png_ptr, name, temp,
+ "Gray color space not permitted on RGB PNG");
+ break;
+
+ default:
+ return png_icc_profile_error(png_ptr, name, temp,
+ "invalid ICC profile color space");
+ }
+
+ /* It is up to the application to check that the profile class matches the
+ * application requirements; the spec provides no guidance, but it's pretty
+ * weird if the profile is not scanner ('scnr'), monitor ('mntr'), printer
+ * ('prtr') or 'spac' (for generic color spaces). Issue a warning in these
+ * cases. Issue an error for device link or abstract profiles - these don't
+ * contain the records necessary to transform the color-space to anything
+ * other than the target device (and not even that for an abstract profile).
+ * Profiles of these classes may not be embedded in images.
+ */
+ temp = png_get_uint_32(profile+12); /* profile/device class */
+ switch (temp)
+ {
+ case 0x73636e72: /* 'scnr' */
+ case 0x6d6e7472: /* 'mntr' */
+ case 0x70727472: /* 'prtr' */
+ case 0x73706163: /* 'spac' */
+ /* All supported */
+ break;
+
+ case 0x61627374: /* 'abst' */
+ /* May not be embedded in an image */
+ return png_icc_profile_error(png_ptr, name, temp,
+ "invalid embedded Abstract ICC profile");
+
+ case 0x6c696e6b: /* 'link' */
+ /* DeviceLink profiles cannot be interpreted in a non-device specific
+ * fashion, if an app uses the AToB0Tag in the profile the results are
+ * undefined unless the result is sent to the intended device,
+ * therefore a DeviceLink profile should not be found embedded in a
+ * PNG.
+ */
+ return png_icc_profile_error(png_ptr, name, temp,
+ "unexpected DeviceLink ICC profile class");
+
+ case 0x6e6d636c: /* 'nmcl' */
+ /* A NamedColor profile is also device specific, however it doesn't
+ * contain an AToB0 tag that is open to misinterpretation. Almost
+ * certainly it will fail the tests below.
+ */
+ (void)png_icc_profile_error(png_ptr, name, temp,
+ "unexpected NamedColor ICC profile class");
+ break;
+
+ default:
+ /* To allow for future enhancements to the profile accept unrecognized
+ * profile classes with a warning, these then hit the test below on the
+ * tag content to ensure they are backward compatible with one of the
+ * understood profiles.
+ */
+ (void)png_icc_profile_error(png_ptr, name, temp,
+ "unrecognized ICC profile class");
+ break;
+ }
+
+ /* For any profile other than a device link one the PCS must be encoded
+ * either in XYZ or Lab.
+ */
+ temp = png_get_uint_32(profile+20);
+ switch (temp)
+ {
+ case 0x58595a20: /* 'XYZ ' */
+ case 0x4c616220: /* 'Lab ' */
+ break;
+
+ default:
+ return png_icc_profile_error(png_ptr, name, temp,
+ "unexpected ICC PCS encoding");
+ }
+
+ return 1;
+}
+
+int /* PRIVATE */
+png_icc_check_tag_table(png_const_structrp png_ptr, png_const_charp name,
+ png_uint_32 profile_length,
+ png_const_bytep profile /* header plus whole tag table */)
+{
+ png_uint_32 tag_count = png_get_uint_32(profile+128);
+ png_uint_32 itag;
+ png_const_bytep tag = profile+132; /* The first tag */
+
+ /* First scan all the tags in the table and add bits to the icc_info value
+ * (temporarily in 'tags').
+ */
+ for (itag=0; itag < tag_count; ++itag, tag += 12)
+ {
+ png_uint_32 tag_id = png_get_uint_32(tag+0);
+ png_uint_32 tag_start = png_get_uint_32(tag+4); /* must be aligned */
+ png_uint_32 tag_length = png_get_uint_32(tag+8);/* not padded */
+
+ /* The ICC specification does not exclude zero length tags, therefore the
+ * start might actually be anywhere if there is no data, but this would be
+ * a clear abuse of the intent of the standard so the start is checked for
+ * being in range. All defined tag types have an 8 byte header - a 4 byte
+ * type signature then 0.
+ */
+
+ /* This is a hard error; potentially it can cause read outside the
+ * profile.
+ */
+ if (tag_start > profile_length || tag_length > profile_length - tag_start)
+ return png_icc_profile_error(png_ptr, name, tag_id,
+ "ICC profile tag outside profile");
+
+ if ((tag_start & 3) != 0)
+ {
+ /* CNHP730S.icc shipped with Microsoft Windows 64 violates this; it is
+ * only a warning here because libpng does not care about the
+ * alignment.
+ */
+ (void)png_icc_profile_error(png_ptr, name, tag_id,
+ "ICC profile tag start not a multiple of 4");
+ }
+ }
+
+ return 1; /* success, maybe with warnings */
+}
+#endif /* READ_iCCP */
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+#if (defined PNG_READ_mDCV_SUPPORTED) || (defined PNG_READ_cHRM_SUPPORTED)
+static int
+have_chromaticities(png_const_structrp png_ptr)
+{
+ /* Handle new PNGv3 chunks and the precedence rules to determine whether
+ * png_struct::chromaticities must be processed. Only required for RGB to
+ * gray.
+ *
+ * mDCV: this is the mastering colour space and it is independent of the
+ * encoding so it needs to be used regardless of the encoded space.
+ *
+ * cICP: first in priority but not yet implemented - the chromaticities come
+ * from the 'primaries'.
+ *
+ * iCCP: not supported by libpng (so ignored)
+ *
+ * sRGB: the defaults match sRGB
+ *
+ * cHRM: calculate the coefficients
+ */
+# ifdef PNG_READ_mDCV_SUPPORTED
+ if (png_has_chunk(png_ptr, mDCV))
+ return 1;
+# define check_chromaticities 1
+# endif /*mDCV*/
+
+# ifdef PNG_READ_sRGB_SUPPORTED
+ if (png_has_chunk(png_ptr, sRGB))
+ return 0;
+# endif /*sRGB*/
+
+# ifdef PNG_READ_cHRM_SUPPORTED
+ if (png_has_chunk(png_ptr, cHRM))
+ return 1;
+# define check_chromaticities 1
+# endif /*cHRM*/
+
+ return 0; /* sRGB defaults */
+}
+#endif /* READ_mDCV || READ_cHRM */
+
+void /* PRIVATE */
+png_set_rgb_coefficients(png_structrp png_ptr)
+{
+ /* Set the rgb_to_gray coefficients from the colorspace if available. Note
+ * that '_set' means that png_rgb_to_gray was called **and** it successfully
+ * set up the coefficients.
+ */
+ if (png_ptr->rgb_to_gray_coefficients_set == 0)
+ {
+# if check_chromaticities
+ png_XYZ xyz;
+
+ if (have_chromaticities(png_ptr) &&
+ png_XYZ_from_xy(&xyz, &png_ptr->chromaticities) == 0)
+ {
+ /* png_set_rgb_to_gray has not set the coefficients, get them from the
+ * Y * values of the colorspace colorants.
+ */
+ png_fixed_point r = xyz.red_Y;
+ png_fixed_point g = xyz.green_Y;
+ png_fixed_point b = xyz.blue_Y;
+ png_fixed_point total = r+g+b;
+
+ if (total > 0 &&
+ r >= 0 && png_muldiv(&r, r, 32768, total) && r >= 0 && r <= 32768 &&
+ g >= 0 && png_muldiv(&g, g, 32768, total) && g >= 0 && g <= 32768 &&
+ b >= 0 && png_muldiv(&b, b, 32768, total) && b >= 0 && b <= 32768 &&
+ r+g+b <= 32769)
+ {
+ /* We allow 0 coefficients here. r+g+b may be 32769 if two or
+ * all of the coefficients were rounded up. Handle this by
+ * reducing the *largest* coefficient by 1; this matches the
+ * approach used for the default coefficients in pngrtran.c
+ */
+ int add = 0;
+
+ if (r+g+b > 32768)
+ add = -1;
+ else if (r+g+b < 32768)
+ add = 1;
+
+ if (add != 0)
+ {
+ if (g >= r && g >= b)
+ g += add;
+ else if (r >= g && r >= b)
+ r += add;
+ else
+ b += add;
+ }
+
+ /* Check for an internal error. */
+ if (r+g+b != 32768)
+ png_error(png_ptr,
+ "internal error handling cHRM coefficients");
+
+ else
+ {
+ png_ptr->rgb_to_gray_red_coeff = (png_uint_16)r;
+ png_ptr->rgb_to_gray_green_coeff = (png_uint_16)g;
+ }
+ }
+ }
+ else
+# endif /* check_chromaticities */
+ {
+ /* Use the historical REC 709 (etc) values: */
+ png_ptr->rgb_to_gray_red_coeff = 6968;
+ png_ptr->rgb_to_gray_green_coeff = 23434;
+ /* png_ptr->rgb_to_gray_blue_coeff = 2366; */
+ }
+ }
+}
+#endif /* READ_RGB_TO_GRAY */
+
+void /* PRIVATE */
+png_check_IHDR(png_const_structrp png_ptr,
+ png_uint_32 width, png_uint_32 height, int bit_depth,
+ int color_type, int interlace_type, int compression_type,
+ int filter_type)
+{
+ int error = 0;
+
+ /* Check for width and height valid values */
+ if (width == 0)
+ {
+ png_warning(png_ptr, "Image width is zero in IHDR");
+ error = 1;
+ }
+
+ if (width > PNG_UINT_31_MAX)
+ {
+ png_warning(png_ptr, "Invalid image width in IHDR");
+ error = 1;
+ }
+
+ /* The bit mask on the first line below must be at least as big as a
+ * png_uint_32. "~7U" is not adequate on 16-bit systems because it will
+ * be an unsigned 16-bit value. Casting to (png_alloc_size_t) makes the
+ * type of the result at least as bit (in bits) as the RHS of the > operator
+ * which also avoids a common warning on 64-bit systems that the comparison
+ * of (png_uint_32) against the constant value on the RHS will always be
+ * false.
+ */
+ if (((width + 7) & ~(png_alloc_size_t)7) >
+ (((PNG_SIZE_MAX
+ - 48 /* big_row_buf hack */
+ - 1) /* filter byte */
+ / 8) /* 8-byte RGBA pixels */
+ - 1)) /* extra max_pixel_depth pad */
+ {
+ /* The size of the row must be within the limits of this architecture.
+ * Because the read code can perform arbitrary transformations the
+ * maximum size is checked here. Because the code in png_read_start_row
+ * adds extra space "for safety's sake" in several places a conservative
+ * limit is used here.
+ *
+ * NOTE: it would be far better to check the size that is actually used,
+ * but the effect in the real world is minor and the changes are more
+ * extensive, therefore much more dangerous and much more difficult to
+ * write in a way that avoids compiler warnings.
+ */
+ png_warning(png_ptr, "Image width is too large for this architecture");
+ error = 1;
+ }
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+ if (width > png_ptr->user_width_max)
+#else
+ if (width > PNG_USER_WIDTH_MAX)
+#endif
+ {
+ png_warning(png_ptr, "Image width exceeds user limit in IHDR");
+ error = 1;
+ }
+
+ if (height == 0)
+ {
+ png_warning(png_ptr, "Image height is zero in IHDR");
+ error = 1;
+ }
+
+ if (height > PNG_UINT_31_MAX)
+ {
+ png_warning(png_ptr, "Invalid image height in IHDR");
+ error = 1;
+ }
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+ if (height > png_ptr->user_height_max)
+#else
+ if (height > PNG_USER_HEIGHT_MAX)
+#endif
+ {
+ png_warning(png_ptr, "Image height exceeds user limit in IHDR");
+ error = 1;
+ }
+
+ /* Check other values */
+ if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 &&
+ bit_depth != 8 && bit_depth != 16)
+ {
+ png_warning(png_ptr, "Invalid bit depth in IHDR");
+ error = 1;
+ }
+
+ if (color_type < 0 || color_type == 1 ||
+ color_type == 5 || color_type > 6)
+ {
+ png_warning(png_ptr, "Invalid color type in IHDR");
+ error = 1;
+ }
+
+ if (((color_type == PNG_COLOR_TYPE_PALETTE) && bit_depth > 8) ||
+ ((color_type == PNG_COLOR_TYPE_RGB ||
+ color_type == PNG_COLOR_TYPE_GRAY_ALPHA ||
+ color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8))
+ {
+ png_warning(png_ptr, "Invalid color type/bit depth combination in IHDR");
+ error = 1;
+ }
+
+ if (interlace_type >= PNG_INTERLACE_LAST)
+ {
+ png_warning(png_ptr, "Unknown interlace method in IHDR");
+ error = 1;
+ }
+
+ if (compression_type != PNG_COMPRESSION_TYPE_BASE)
+ {
+ png_warning(png_ptr, "Unknown compression method in IHDR");
+ error = 1;
+ }
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ /* Accept filter_method 64 (intrapixel differencing) only if
+ * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
+ * 2. Libpng did not read a PNG signature (this filter_method is only
+ * used in PNG datastreams that are embedded in MNG datastreams) and
+ * 3. The application called png_permit_mng_features with a mask that
+ * included PNG_FLAG_MNG_FILTER_64 and
+ * 4. The filter_method is 64 and
+ * 5. The color_type is RGB or RGBA
+ */
+ if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0 &&
+ png_ptr->mng_features_permitted != 0)
+ png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
+
+ if (filter_type != PNG_FILTER_TYPE_BASE)
+ {
+ if (!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
+ (filter_type == PNG_INTRAPIXEL_DIFFERENCING) &&
+ ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) == 0) &&
+ (color_type == PNG_COLOR_TYPE_RGB ||
+ color_type == PNG_COLOR_TYPE_RGB_ALPHA)))
+ {
+ png_warning(png_ptr, "Unknown filter method in IHDR");
+ error = 1;
+ }
+
+ if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0)
+ {
+ png_warning(png_ptr, "Invalid filter method in IHDR");
+ error = 1;
+ }
+ }
+
+#else
+ if (filter_type != PNG_FILTER_TYPE_BASE)
+ {
+ png_warning(png_ptr, "Unknown filter method in IHDR");
+ error = 1;
+ }
+#endif
+
+ if (error == 1)
+ png_error(png_ptr, "Invalid IHDR data");
+}
+
+#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
+/* ASCII to fp functions */
+/* Check an ASCII formatted floating point value, see the more detailed
+ * comments in pngpriv.h
+ */
+/* The following is used internally to preserve the sticky flags */
+#define png_fp_add(state, flags) ((state) |= (flags))
+#define png_fp_set(state, value) ((state) = (value) | ((state) & PNG_FP_STICKY))
+
+int /* PRIVATE */
+png_check_fp_number(png_const_charp string, size_t size, int *statep,
+ size_t *whereami)
+{
+ int state = *statep;
+ size_t i = *whereami;
+
+ while (i < size)
+ {
+ int type;
+ /* First find the type of the next character */
+ switch (string[i])
+ {
+ case 43: type = PNG_FP_SAW_SIGN; break;
+ case 45: type = PNG_FP_SAW_SIGN + PNG_FP_NEGATIVE; break;
+ case 46: type = PNG_FP_SAW_DOT; break;
+ case 48: type = PNG_FP_SAW_DIGIT; break;
+ case 49: case 50: case 51: case 52:
+ case 53: case 54: case 55: case 56:
+ case 57: type = PNG_FP_SAW_DIGIT + PNG_FP_NONZERO; break;
+ case 69:
+ case 101: type = PNG_FP_SAW_E; break;
+ default: goto PNG_FP_End;
+ }
+
+ /* Now deal with this type according to the current
+ * state, the type is arranged to not overlap the
+ * bits of the PNG_FP_STATE.
+ */
+ switch ((state & PNG_FP_STATE) + (type & PNG_FP_SAW_ANY))
+ {
+ case PNG_FP_INTEGER + PNG_FP_SAW_SIGN:
+ if ((state & PNG_FP_SAW_ANY) != 0)
+ goto PNG_FP_End; /* not a part of the number */
+
+ png_fp_add(state, type);
+ break;
+
+ case PNG_FP_INTEGER + PNG_FP_SAW_DOT:
+ /* Ok as trailer, ok as lead of fraction. */
+ if ((state & PNG_FP_SAW_DOT) != 0) /* two dots */
+ goto PNG_FP_End;
+
+ else if ((state & PNG_FP_SAW_DIGIT) != 0) /* trailing dot? */
+ png_fp_add(state, type);
+
+ else
+ png_fp_set(state, PNG_FP_FRACTION | type);
+
+ break;
+
+ case PNG_FP_INTEGER + PNG_FP_SAW_DIGIT:
+ if ((state & PNG_FP_SAW_DOT) != 0) /* delayed fraction */
+ png_fp_set(state, PNG_FP_FRACTION | PNG_FP_SAW_DOT);
+
+ png_fp_add(state, type | PNG_FP_WAS_VALID);
+
+ break;
+
+ case PNG_FP_INTEGER + PNG_FP_SAW_E:
+ if ((state & PNG_FP_SAW_DIGIT) == 0)
+ goto PNG_FP_End;
+
+ png_fp_set(state, PNG_FP_EXPONENT);
+
+ break;
+
+ /* case PNG_FP_FRACTION + PNG_FP_SAW_SIGN:
+ goto PNG_FP_End; ** no sign in fraction */
+
+ /* case PNG_FP_FRACTION + PNG_FP_SAW_DOT:
+ goto PNG_FP_End; ** Because SAW_DOT is always set */
+
+ case PNG_FP_FRACTION + PNG_FP_SAW_DIGIT:
+ png_fp_add(state, type | PNG_FP_WAS_VALID);
+ break;
+
+ case PNG_FP_FRACTION + PNG_FP_SAW_E:
+ /* This is correct because the trailing '.' on an
+ * integer is handled above - so we can only get here
+ * with the sequence ".E" (with no preceding digits).
+ */
+ if ((state & PNG_FP_SAW_DIGIT) == 0)
+ goto PNG_FP_End;
+
+ png_fp_set(state, PNG_FP_EXPONENT);
+
+ break;
+
+ case PNG_FP_EXPONENT + PNG_FP_SAW_SIGN:
+ if ((state & PNG_FP_SAW_ANY) != 0)
+ goto PNG_FP_End; /* not a part of the number */
+
+ png_fp_add(state, PNG_FP_SAW_SIGN);
+
+ break;
+
+ /* case PNG_FP_EXPONENT + PNG_FP_SAW_DOT:
+ goto PNG_FP_End; */
+
+ case PNG_FP_EXPONENT + PNG_FP_SAW_DIGIT:
+ png_fp_add(state, PNG_FP_SAW_DIGIT | PNG_FP_WAS_VALID);
+
+ break;
+
+ /* case PNG_FP_EXPONEXT + PNG_FP_SAW_E:
+ goto PNG_FP_End; */
+
+ default: goto PNG_FP_End; /* I.e. break 2 */
+ }
+
+ /* The character seems ok, continue. */
+ ++i;
+ }
+
+PNG_FP_End:
+ /* Here at the end, update the state and return the correct
+ * return code.
+ */
+ *statep = state;
+ *whereami = i;
+
+ return (state & PNG_FP_SAW_DIGIT) != 0;
+}
+
+
+/* The same but for a complete string. */
+int
+png_check_fp_string(png_const_charp string, size_t size)
+{
+ int state=0;
+ size_t char_index=0;
+
+ if (png_check_fp_number(string, size, &state, &char_index) != 0 &&
+ (char_index == size || string[char_index] == 0))
+ return state /* must be non-zero - see above */;
+
+ return 0; /* i.e. fail */
+}
+#endif /* pCAL || sCAL */
+
+#ifdef PNG_sCAL_SUPPORTED
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+/* Utility used below - a simple accurate power of ten from an integral
+ * exponent.
+ */
+static double
+png_pow10(int power)
+{
+ int recip = 0;
+ double d = 1;
+
+ /* Handle negative exponent with a reciprocal at the end because
+ * 10 is exact whereas .1 is inexact in base 2
+ */
+ if (power < 0)
+ {
+ if (power < DBL_MIN_10_EXP) return 0;
+ recip = 1; power = -power;
+ }
+
+ if (power > 0)
+ {
+ /* Decompose power bitwise. */
+ double mult = 10;
+ do
+ {
+ if (power & 1) d *= mult;
+ mult *= mult;
+ power >>= 1;
+ }
+ while (power > 0);
+
+ if (recip != 0) d = 1/d;
+ }
+ /* else power is 0 and d is 1 */
+
+ return d;
+}
+
+/* Function to format a floating point value in ASCII with a given
+ * precision.
+ */
+void /* PRIVATE */
+png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, size_t size,
+ double fp, unsigned int precision)
+{
+ /* We use standard functions from math.h, but not printf because
+ * that would require stdio. The caller must supply a buffer of
+ * sufficient size or we will png_error. The tests on size and
+ * the space in ascii[] consumed are indicated below.
+ */
+ if (precision < 1)
+ precision = DBL_DIG;
+
+ /* Enforce the limit of the implementation precision too. */
+ if (precision > DBL_DIG+1)
+ precision = DBL_DIG+1;
+
+ /* Basic sanity checks */
+ if (size >= precision+5) /* See the requirements below. */
+ {
+ if (fp < 0)
+ {
+ fp = -fp;
+ *ascii++ = 45; /* '-' PLUS 1 TOTAL 1 */
+ --size;
+ }
+
+ if (fp >= DBL_MIN && fp <= DBL_MAX)
+ {
+ int exp_b10; /* A base 10 exponent */
+ double base; /* 10^exp_b10 */
+
+ /* First extract a base 10 exponent of the number,
+ * the calculation below rounds down when converting
+ * from base 2 to base 10 (multiply by log10(2) -
+ * 0.3010, but 77/256 is 0.3008, so exp_b10 needs to
+ * be increased. Note that the arithmetic shift
+ * performs a floor() unlike C arithmetic - using a
+ * C multiply would break the following for negative
+ * exponents.
+ */
+ (void)frexp(fp, &exp_b10); /* exponent to base 2 */
+
+ exp_b10 = (exp_b10 * 77) >> 8; /* <= exponent to base 10 */
+
+ /* Avoid underflow here. */
+ base = png_pow10(exp_b10); /* May underflow */
+
+ while (base < DBL_MIN || base < fp)
+ {
+ /* And this may overflow. */
+ double test = png_pow10(exp_b10+1);
+
+ if (test <= DBL_MAX)
+ {
+ ++exp_b10; base = test;
+ }
+
+ else
+ break;
+ }
+
+ /* Normalize fp and correct exp_b10, after this fp is in the
+ * range [.1,1) and exp_b10 is both the exponent and the digit
+ * *before* which the decimal point should be inserted
+ * (starting with 0 for the first digit). Note that this
+ * works even if 10^exp_b10 is out of range because of the
+ * test on DBL_MAX above.
+ */
+ fp /= base;
+ while (fp >= 1)
+ {
+ fp /= 10; ++exp_b10;
+ }
+
+ /* Because of the code above fp may, at this point, be
+ * less than .1, this is ok because the code below can
+ * handle the leading zeros this generates, so no attempt
+ * is made to correct that here.
+ */
+
+ {
+ unsigned int czero, clead, cdigits;
+ char exponent[10];
+
+ /* Allow up to two leading zeros - this will not lengthen
+ * the number compared to using E-n.
+ */
+ if (exp_b10 < 0 && exp_b10 > -3) /* PLUS 3 TOTAL 4 */
+ {
+ czero = 0U-exp_b10; /* PLUS 2 digits: TOTAL 3 */
+ exp_b10 = 0; /* Dot added below before first output. */
+ }
+ else
+ czero = 0; /* No zeros to add */
+
+ /* Generate the digit list, stripping trailing zeros and
+ * inserting a '.' before a digit if the exponent is 0.
+ */
+ clead = czero; /* Count of leading zeros */
+ cdigits = 0; /* Count of digits in list. */
+
+ do
+ {
+ double d;
+
+ fp *= 10;
+ /* Use modf here, not floor and subtract, so that
+ * the separation is done in one step. At the end
+ * of the loop don't break the number into parts so
+ * that the final digit is rounded.
+ */
+ if (cdigits+czero+1 < precision+clead)
+ fp = modf(fp, &d);
+
+ else
+ {
+ d = floor(fp + .5);
+
+ if (d > 9)
+ {
+ /* Rounding up to 10, handle that here. */
+ if (czero > 0)
+ {
+ --czero; d = 1;
+ if (cdigits == 0) --clead;
+ }
+ else
+ {
+ while (cdigits > 0 && d > 9)
+ {
+ int ch = *--ascii;
+
+ if (exp_b10 != (-1))
+ ++exp_b10;
+
+ else if (ch == 46)
+ {
+ ch = *--ascii; ++size;
+ /* Advance exp_b10 to '1', so that the
+ * decimal point happens after the
+ * previous digit.
+ */
+ exp_b10 = 1;
+ }
+
+ --cdigits;
+ d = ch - 47; /* I.e. 1+(ch-48) */
+ }
+
+ /* Did we reach the beginning? If so adjust the
+ * exponent but take into account the leading
+ * decimal point.
+ */
+ if (d > 9) /* cdigits == 0 */
+ {
+ if (exp_b10 == (-1))
+ {
+ /* Leading decimal point (plus zeros?), if
+ * we lose the decimal point here it must
+ * be reentered below.
+ */
+ int ch = *--ascii;
+
+ if (ch == 46)
+ {
+ ++size; exp_b10 = 1;
+ }
+
+ /* Else lost a leading zero, so 'exp_b10' is
+ * still ok at (-1)
+ */
+ }
+ else
+ ++exp_b10;
+
+ /* In all cases we output a '1' */
+ d = 1;
+ }
+ }
+ }
+ fp = 0; /* Guarantees termination below. */
+ }
+
+ if (d == 0)
+ {
+ ++czero;
+ if (cdigits == 0) ++clead;
+ }
+ else
+ {
+ /* Included embedded zeros in the digit count. */
+ cdigits += czero - clead;
+ clead = 0;
+
+ while (czero > 0)
+ {
+ /* exp_b10 == (-1) means we just output the decimal
+ * place - after the DP don't adjust 'exp_b10' any
+ * more!
+ */
+ if (exp_b10 != (-1))
+ {
+ if (exp_b10 == 0)
+ {
+ *ascii++ = 46; --size;
+ }
+ /* PLUS 1: TOTAL 4 */
+ --exp_b10;
+ }
+ *ascii++ = 48; --czero;
+ }
+
+ if (exp_b10 != (-1))
+ {
+ if (exp_b10 == 0)
+ {
+ *ascii++ = 46; --size; /* counted above */
+ }
+
+ --exp_b10;
+ }
+ *ascii++ = (char)(48 + (int)d); ++cdigits;
+ }
+ }
+ while (cdigits+czero < precision+clead && fp > DBL_MIN);
+
+ /* The total output count (max) is now 4+precision */
+
+ /* Check for an exponent, if we don't need one we are
+ * done and just need to terminate the string. At this
+ * point, exp_b10==(-1) is effectively a flag: it got
+ * to '-1' because of the decrement, after outputting
+ * the decimal point above. (The exponent required is
+ * *not* -1.)
+ */
+ if (exp_b10 >= (-1) && exp_b10 <= 2)
+ {
+ /* The following only happens if we didn't output the
+ * leading zeros above for negative exponent, so this
+ * doesn't add to the digit requirement. Note that the
+ * two zeros here can only be output if the two leading
+ * zeros were *not* output, so this doesn't increase
+ * the output count.
+ */
+ while (exp_b10-- > 0) *ascii++ = 48;
+
+ *ascii = 0;
+
+ /* Total buffer requirement (including the '\0') is
+ * 5+precision - see check at the start.
+ */
+ return;
+ }
+
+ /* Here if an exponent is required, adjust size for
+ * the digits we output but did not count. The total
+ * digit output here so far is at most 1+precision - no
+ * decimal point and no leading or trailing zeros have
+ * been output.
+ */
+ size -= cdigits;
+
+ *ascii++ = 69; --size; /* 'E': PLUS 1 TOTAL 2+precision */
+
+ /* The following use of an unsigned temporary avoids ambiguities in
+ * the signed arithmetic on exp_b10 and permits GCC at least to do
+ * better optimization.
+ */
+ {
+ unsigned int uexp_b10;
+
+ if (exp_b10 < 0)
+ {
+ *ascii++ = 45; --size; /* '-': PLUS 1 TOTAL 3+precision */
+ uexp_b10 = 0U-exp_b10;
+ }
+
+ else
+ uexp_b10 = 0U+exp_b10;
+
+ cdigits = 0;
+
+ while (uexp_b10 > 0)
+ {
+ exponent[cdigits++] = (char)(48 + uexp_b10 % 10);
+ uexp_b10 /= 10;
+ }
+ }
+
+ /* Need another size check here for the exponent digits, so
+ * this need not be considered above.
+ */
+ if (size > cdigits)
+ {
+ while (cdigits > 0) *ascii++ = exponent[--cdigits];
+
+ *ascii = 0;
+
+ return;
+ }
+ }
+ }
+ else if (!(fp >= DBL_MIN))
+ {
+ *ascii++ = 48; /* '0' */
+ *ascii = 0;
+ return;
+ }
+ else
+ {
+ *ascii++ = 105; /* 'i' */
+ *ascii++ = 110; /* 'n' */
+ *ascii++ = 102; /* 'f' */
+ *ascii = 0;
+ return;
+ }
+ }
+
+ /* Here on buffer too small. */
+ png_error(png_ptr, "ASCII conversion buffer too small");
+}
+# endif /* FLOATING_POINT */
+
+# ifdef PNG_FIXED_POINT_SUPPORTED
+/* Function to format a fixed point value in ASCII.
+ */
+void /* PRIVATE */
+png_ascii_from_fixed(png_const_structrp png_ptr, png_charp ascii,
+ size_t size, png_fixed_point fp)
+{
+ /* Require space for 10 decimal digits, a decimal point, a minus sign and a
+ * trailing \0, 13 characters:
+ */
+ if (size > 12)
+ {
+ png_uint_32 num;
+
+ /* Avoid overflow here on the minimum integer. */
+ if (fp < 0)
+ {
+ *ascii++ = 45; num = (png_uint_32)(-fp);
+ }
+ else
+ num = (png_uint_32)fp;
+
+ if (num <= 0x80000000) /* else overflowed */
+ {
+ unsigned int ndigits = 0, first = 16 /* flag value */;
+ char digits[10] = {0};
+
+ while (num)
+ {
+ /* Split the low digit off num: */
+ unsigned int tmp = num/10;
+ num -= tmp*10;
+ digits[ndigits++] = (char)(48 + num);
+ /* Record the first non-zero digit, note that this is a number
+ * starting at 1, it's not actually the array index.
+ */
+ if (first == 16 && num > 0)
+ first = ndigits;
+ num = tmp;
+ }
+
+ if (ndigits > 0)
+ {
+ while (ndigits > 5) *ascii++ = digits[--ndigits];
+ /* The remaining digits are fractional digits, ndigits is '5' or
+ * smaller at this point. It is certainly not zero. Check for a
+ * non-zero fractional digit:
+ */
+ if (first <= 5)
+ {
+ unsigned int i;
+ *ascii++ = 46; /* decimal point */
+ /* ndigits may be <5 for small numbers, output leading zeros
+ * then ndigits digits to first:
+ */
+ i = 5;
+ while (ndigits < i)
+ {
+ *ascii++ = 48; --i;
+ }
+ while (ndigits >= first) *ascii++ = digits[--ndigits];
+ /* Don't output the trailing zeros! */
+ }
+ }
+ else
+ *ascii++ = 48;
+
+ /* And null terminate the string: */
+ *ascii = 0;
+ return;
+ }
+ }
+
+ /* Here on buffer too small. */
+ png_error(png_ptr, "ASCII conversion buffer too small");
+}
+# endif /* FIXED_POINT */
+#endif /* SCAL */
+
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
+ !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
+ (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \
+ defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \
+ (defined(PNG_sCAL_SUPPORTED) && \
+ defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
+png_fixed_point
+png_fixed(png_const_structrp png_ptr, double fp, png_const_charp text)
+{
+ double r = floor(100000 * fp + .5);
+
+ if (r > 2147483647. || r < -2147483648.)
+ png_fixed_error(png_ptr, text);
+
+# ifndef PNG_ERROR_TEXT_SUPPORTED
+ PNG_UNUSED(text)
+# endif
+
+ return (png_fixed_point)r;
+}
+#endif
+
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
+ !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
+ (defined(PNG_cLLI_SUPPORTED) || defined(PNG_mDCV_SUPPORTED))
+png_uint_32
+png_fixed_ITU(png_const_structrp png_ptr, double fp, png_const_charp text)
+{
+ double r = floor(10000 * fp + .5);
+
+ if (r > 2147483647. || r < 0)
+ png_fixed_error(png_ptr, text);
+
+# ifndef PNG_ERROR_TEXT_SUPPORTED
+ PNG_UNUSED(text)
+# endif
+
+ return (png_uint_32)r;
+}
+#endif
+
+
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_COLORSPACE_SUPPORTED) ||\
+ defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
+/* muldiv functions */
+/* This API takes signed arguments and rounds the result to the nearest
+ * integer (or, for a fixed point number - the standard argument - to
+ * the nearest .00001). Overflow and divide by zero are signalled in
+ * the result, a boolean - true on success, false on overflow.
+ */
+int /* PRIVATE */
+png_muldiv(png_fixed_point_p res, png_fixed_point a, png_int_32 times,
+ png_int_32 divisor)
+{
+ /* Return a * times / divisor, rounded. */
+ if (divisor != 0)
+ {
+ if (a == 0 || times == 0)
+ {
+ *res = 0;
+ return 1;
+ }
+ else
+ {
+#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+ double r = a;
+ r *= times;
+ r /= divisor;
+ r = floor(r+.5);
+
+ /* A png_fixed_point is a 32-bit integer. */
+ if (r <= 2147483647. && r >= -2147483648.)
+ {
+ *res = (png_fixed_point)r;
+ return 1;
+ }
+#else
+ int negative = 0;
+ png_uint_32 A, T, D;
+ png_uint_32 s16, s32, s00;
+
+ if (a < 0)
+ negative = 1, A = -a;
+ else
+ A = a;
+
+ if (times < 0)
+ negative = !negative, T = -times;
+ else
+ T = times;
+
+ if (divisor < 0)
+ negative = !negative, D = -divisor;
+ else
+ D = divisor;
+
+ /* Following can't overflow because the arguments only
+ * have 31 bits each, however the result may be 32 bits.
+ */
+ s16 = (A >> 16) * (T & 0xffff) +
+ (A & 0xffff) * (T >> 16);
+ /* Can't overflow because the a*times bit is only 30
+ * bits at most.
+ */
+ s32 = (A >> 16) * (T >> 16) + (s16 >> 16);
+ s00 = (A & 0xffff) * (T & 0xffff);
+
+ s16 = (s16 & 0xffff) << 16;
+ s00 += s16;
+
+ if (s00 < s16)
+ ++s32; /* carry */
+
+ if (s32 < D) /* else overflow */
+ {
+ /* s32.s00 is now the 64-bit product, do a standard
+ * division, we know that s32 < D, so the maximum
+ * required shift is 31.
+ */
+ int bitshift = 32;
+ png_fixed_point result = 0; /* NOTE: signed */
+
+ while (--bitshift >= 0)
+ {
+ png_uint_32 d32, d00;
+
+ if (bitshift > 0)
+ d32 = D >> (32-bitshift), d00 = D << bitshift;
+
+ else
+ d32 = 0, d00 = D;
+
+ if (s32 > d32)
+ {
+ if (s00 < d00) --s32; /* carry */
+ s32 -= d32, s00 -= d00, result += 1<= d00)
+ s32 = 0, s00 -= d00, result += 1<= (D >> 1))
+ ++result;
+
+ if (negative != 0)
+ result = -result;
+
+ /* Check for overflow. */
+ if ((negative != 0 && result <= 0) ||
+ (negative == 0 && result >= 0))
+ {
+ *res = result;
+ return 1;
+ }
+ }
+#endif
+ }
+ }
+
+ return 0;
+}
+
+/* Calculate a reciprocal, return 0 on div-by-zero or overflow. */
+png_fixed_point
+png_reciprocal(png_fixed_point a)
+{
+#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+ double r = floor(1E10/a+.5);
+
+ if (r <= 2147483647. && r >= -2147483648.)
+ return (png_fixed_point)r;
+#else
+ png_fixed_point res;
+
+ if (png_muldiv(&res, 100000, 100000, a) != 0)
+ return res;
+#endif
+
+ return 0; /* error/overflow */
+}
+#endif /* READ_GAMMA || COLORSPACE || INCH_CONVERSIONS || READ_pHYS */
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* This is the shared test on whether a gamma value is 'significant' - whether
+ * it is worth doing gamma correction.
+ */
+int /* PRIVATE */
+png_gamma_significant(png_fixed_point gamma_val)
+{
+ /* sRGB: 1/2.2 == 0.4545(45)
+ * AdobeRGB: 1/(2+51/256) ~= 0.45471 5dp
+ *
+ * So the correction from AdobeRGB to sRGB (output) is:
+ *
+ * 2.2/(2+51/256) == 1.00035524
+ *
+ * I.e. vanishly small (<4E-4) but still detectable in 16-bit linear (+/-
+ * 23). Note that the Adobe choice seems to be something intended to give an
+ * exact number with 8 binary fractional digits - it is the closest to 2.2
+ * that is possible a base 2 .8p representation.
+ */
+ return gamma_val < PNG_FP_1 - PNG_GAMMA_THRESHOLD_FIXED ||
+ gamma_val > PNG_FP_1 + PNG_GAMMA_THRESHOLD_FIXED;
+}
+
+#ifndef PNG_FLOATING_ARITHMETIC_SUPPORTED
+/* A local convenience routine. */
+static png_fixed_point
+png_product2(png_fixed_point a, png_fixed_point b)
+{
+ /* The required result is a * b; the following preserves accuracy. */
+#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED /* Should now be unused */
+ double r = a * 1E-5;
+ r *= b;
+ r = floor(r+.5);
+
+ if (r <= 2147483647. && r >= -2147483648.)
+ return (png_fixed_point)r;
+#else
+ png_fixed_point res;
+
+ if (png_muldiv(&res, a, b, 100000) != 0)
+ return res;
+#endif
+
+ return 0; /* overflow */
+}
+#endif /* FLOATING_ARITHMETIC */
+
+png_fixed_point
+png_reciprocal2(png_fixed_point a, png_fixed_point b)
+{
+ /* The required result is 1/a * 1/b; the following preserves accuracy. */
+#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+ if (a != 0 && b != 0)
+ {
+ double r = 1E15/a;
+ r /= b;
+ r = floor(r+.5);
+
+ if (r <= 2147483647. && r >= -2147483648.)
+ return (png_fixed_point)r;
+ }
+#else
+ /* This may overflow because the range of png_fixed_point isn't symmetric,
+ * but this API is only used for the product of file and screen gamma so it
+ * doesn't matter that the smallest number it can produce is 1/21474, not
+ * 1/100000
+ */
+ png_fixed_point res = png_product2(a, b);
+
+ if (res != 0)
+ return png_reciprocal(res);
+#endif
+
+ return 0; /* overflow */
+}
+#endif /* READ_GAMMA */
+
+#ifdef PNG_READ_GAMMA_SUPPORTED /* gamma table code */
+#ifndef PNG_FLOATING_ARITHMETIC_SUPPORTED
+/* Fixed point gamma.
+ *
+ * The code to calculate the tables used below can be found in the shell script
+ * contrib/tools/intgamma.sh
+ *
+ * To calculate gamma this code implements fast log() and exp() calls using only
+ * fixed point arithmetic. This code has sufficient precision for either 8-bit
+ * or 16-bit sample values.
+ *
+ * The tables used here were calculated using simple 'bc' programs, but C double
+ * precision floating point arithmetic would work fine.
+ *
+ * 8-bit log table
+ * This is a table of -log(value/255)/log(2) for 'value' in the range 128 to
+ * 255, so it's the base 2 logarithm of a normalized 8-bit floating point
+ * mantissa. The numbers are 32-bit fractions.
+ */
+static const png_uint_32
+png_8bit_l2[128] =
+{
+ 4270715492U, 4222494797U, 4174646467U, 4127164793U, 4080044201U, 4033279239U,
+ 3986864580U, 3940795015U, 3895065449U, 3849670902U, 3804606499U, 3759867474U,
+ 3715449162U, 3671346997U, 3627556511U, 3584073329U, 3540893168U, 3498011834U,
+ 3455425220U, 3413129301U, 3371120137U, 3329393864U, 3287946700U, 3246774933U,
+ 3205874930U, 3165243125U, 3124876025U, 3084770202U, 3044922296U, 3005329011U,
+ 2965987113U, 2926893432U, 2888044853U, 2849438323U, 2811070844U, 2772939474U,
+ 2735041326U, 2697373562U, 2659933400U, 2622718104U, 2585724991U, 2548951424U,
+ 2512394810U, 2476052606U, 2439922311U, 2404001468U, 2368287663U, 2332778523U,
+ 2297471715U, 2262364947U, 2227455964U, 2192742551U, 2158222529U, 2123893754U,
+ 2089754119U, 2055801552U, 2022034013U, 1988449497U, 1955046031U, 1921821672U,
+ 1888774511U, 1855902668U, 1823204291U, 1790677560U, 1758320682U, 1726131893U,
+ 1694109454U, 1662251657U, 1630556815U, 1599023271U, 1567649391U, 1536433567U,
+ 1505374214U, 1474469770U, 1443718700U, 1413119487U, 1382670639U, 1352370686U,
+ 1322218179U, 1292211689U, 1262349810U, 1232631153U, 1203054352U, 1173618059U,
+ 1144320946U, 1115161701U, 1086139034U, 1057251672U, 1028498358U, 999877854U,
+ 971388940U, 943030410U, 914801076U, 886699767U, 858725327U, 830876614U,
+ 803152505U, 775551890U, 748073672U, 720716771U, 693480120U, 666362667U,
+ 639363374U, 612481215U, 585715177U, 559064263U, 532527486U, 506103872U,
+ 479792461U, 453592303U, 427502463U, 401522014U, 375650043U, 349885648U,
+ 324227938U, 298676034U, 273229066U, 247886176U, 222646516U, 197509248U,
+ 172473545U, 147538590U, 122703574U, 97967701U, 73330182U, 48790236U,
+ 24347096U, 0U
+
+#if 0
+ /* The following are the values for 16-bit tables - these work fine for the
+ * 8-bit conversions but produce very slightly larger errors in the 16-bit
+ * log (about 1.2 as opposed to 0.7 absolute error in the final value). To
+ * use these all the shifts below must be adjusted appropriately.
+ */
+ 65166, 64430, 63700, 62976, 62257, 61543, 60835, 60132, 59434, 58741, 58054,
+ 57371, 56693, 56020, 55352, 54689, 54030, 53375, 52726, 52080, 51439, 50803,
+ 50170, 49542, 48918, 48298, 47682, 47070, 46462, 45858, 45257, 44661, 44068,
+ 43479, 42894, 42312, 41733, 41159, 40587, 40020, 39455, 38894, 38336, 37782,
+ 37230, 36682, 36137, 35595, 35057, 34521, 33988, 33459, 32932, 32408, 31887,
+ 31369, 30854, 30341, 29832, 29325, 28820, 28319, 27820, 27324, 26830, 26339,
+ 25850, 25364, 24880, 24399, 23920, 23444, 22970, 22499, 22029, 21562, 21098,
+ 20636, 20175, 19718, 19262, 18808, 18357, 17908, 17461, 17016, 16573, 16132,
+ 15694, 15257, 14822, 14390, 13959, 13530, 13103, 12678, 12255, 11834, 11415,
+ 10997, 10582, 10168, 9756, 9346, 8937, 8531, 8126, 7723, 7321, 6921, 6523,
+ 6127, 5732, 5339, 4947, 4557, 4169, 3782, 3397, 3014, 2632, 2251, 1872, 1495,
+ 1119, 744, 372
+#endif
+};
+
+static png_int_32
+png_log8bit(unsigned int x)
+{
+ unsigned int lg2 = 0;
+ /* Each time 'x' is multiplied by 2, 1 must be subtracted off the final log,
+ * because the log is actually negate that means adding 1. The final
+ * returned value thus has the range 0 (for 255 input) to 7.994 (for 1
+ * input), return -1 for the overflow (log 0) case, - so the result is
+ * always at most 19 bits.
+ */
+ if ((x &= 0xff) == 0)
+ return -1;
+
+ if ((x & 0xf0) == 0)
+ lg2 = 4, x <<= 4;
+
+ if ((x & 0xc0) == 0)
+ lg2 += 2, x <<= 2;
+
+ if ((x & 0x80) == 0)
+ lg2 += 1, x <<= 1;
+
+ /* result is at most 19 bits, so this cast is safe: */
+ return (png_int_32)((lg2 << 16) + ((png_8bit_l2[x-128]+32768)>>16));
+}
+
+/* The above gives exact (to 16 binary places) log2 values for 8-bit images,
+ * for 16-bit images we use the most significant 8 bits of the 16-bit value to
+ * get an approximation then multiply the approximation by a correction factor
+ * determined by the remaining up to 8 bits. This requires an additional step
+ * in the 16-bit case.
+ *
+ * We want log2(value/65535), we have log2(v'/255), where:
+ *
+ * value = v' * 256 + v''
+ * = v' * f
+ *
+ * So f is value/v', which is equal to (256+v''/v') since v' is in the range 128
+ * to 255 and v'' is in the range 0 to 255 f will be in the range 256 to less
+ * than 258. The final factor also needs to correct for the fact that our 8-bit
+ * value is scaled by 255, whereas the 16-bit values must be scaled by 65535.
+ *
+ * This gives a final formula using a calculated value 'x' which is value/v' and
+ * scaling by 65536 to match the above table:
+ *
+ * log2(x/257) * 65536
+ *
+ * Since these numbers are so close to '1' we can use simple linear
+ * interpolation between the two end values 256/257 (result -368.61) and 258/257
+ * (result 367.179). The values used below are scaled by a further 64 to give
+ * 16-bit precision in the interpolation:
+ *
+ * Start (256): -23591
+ * Zero (257): 0
+ * End (258): 23499
+ */
+#ifdef PNG_16BIT_SUPPORTED
+static png_int_32
+png_log16bit(png_uint_32 x)
+{
+ unsigned int lg2 = 0;
+
+ /* As above, but now the input has 16 bits. */
+ if ((x &= 0xffff) == 0)
+ return -1;
+
+ if ((x & 0xff00) == 0)
+ lg2 = 8, x <<= 8;
+
+ if ((x & 0xf000) == 0)
+ lg2 += 4, x <<= 4;
+
+ if ((x & 0xc000) == 0)
+ lg2 += 2, x <<= 2;
+
+ if ((x & 0x8000) == 0)
+ lg2 += 1, x <<= 1;
+
+ /* Calculate the base logarithm from the top 8 bits as a 28-bit fractional
+ * value.
+ */
+ lg2 <<= 28;
+ lg2 += (png_8bit_l2[(x>>8)-128]+8) >> 4;
+
+ /* Now we need to interpolate the factor, this requires a division by the top
+ * 8 bits. Do this with maximum precision.
+ */
+ x = ((x << 16) + (x >> 9)) / (x >> 8);
+
+ /* Since we divided by the top 8 bits of 'x' there will be a '1' at 1<<24,
+ * the value at 1<<16 (ignoring this) will be 0 or 1; this gives us exactly
+ * 16 bits to interpolate to get the low bits of the result. Round the
+ * answer. Note that the end point values are scaled by 64 to retain overall
+ * precision and that 'lg2' is current scaled by an extra 12 bits, so adjust
+ * the overall scaling by 6-12. Round at every step.
+ */
+ x -= 1U << 24;
+
+ if (x <= 65536U) /* <= '257' */
+ lg2 += ((23591U * (65536U-x)) + (1U << (16+6-12-1))) >> (16+6-12);
+
+ else
+ lg2 -= ((23499U * (x-65536U)) + (1U << (16+6-12-1))) >> (16+6-12);
+
+ /* Safe, because the result can't have more than 20 bits: */
+ return (png_int_32)((lg2 + 2048) >> 12);
+}
+#endif /* 16BIT */
+
+/* The 'exp()' case must invert the above, taking a 20-bit fixed point
+ * logarithmic value and returning a 16 or 8-bit number as appropriate. In
+ * each case only the low 16 bits are relevant - the fraction - since the
+ * integer bits (the top 4) simply determine a shift.
+ *
+ * The worst case is the 16-bit distinction between 65535 and 65534. This
+ * requires perhaps spurious accuracy in the decoding of the logarithm to
+ * distinguish log2(65535/65534.5) - 10^-5 or 17 bits. There is little chance
+ * of getting this accuracy in practice.
+ *
+ * To deal with this the following exp() function works out the exponent of the
+ * fractional part of the logarithm by using an accurate 32-bit value from the
+ * top four fractional bits then multiplying in the remaining bits.
+ */
+static const png_uint_32
+png_32bit_exp[16] =
+{
+ /* NOTE: the first entry is deliberately set to the maximum 32-bit value. */
+ 4294967295U, 4112874773U, 3938502376U, 3771522796U, 3611622603U, 3458501653U,
+ 3311872529U, 3171459999U, 3037000500U, 2908241642U, 2784941738U, 2666869345U,
+ 2553802834U, 2445529972U, 2341847524U, 2242560872U
+};
+
+/* Adjustment table; provided to explain the numbers in the code below. */
+#if 0
+for (i=11;i>=0;--i){ print i, " ", (1 - e(-(2^i)/65536*l(2))) * 2^(32-i), "\n"}
+ 11 44937.64284865548751208448
+ 10 45180.98734845585101160448
+ 9 45303.31936980687359311872
+ 8 45364.65110595323018870784
+ 7 45395.35850361789624614912
+ 6 45410.72259715102037508096
+ 5 45418.40724413220722311168
+ 4 45422.25021786898173001728
+ 3 45424.17186732298419044352
+ 2 45425.13273269940811464704
+ 1 45425.61317555035558641664
+ 0 45425.85339951654943850496
+#endif
+
+static png_uint_32
+png_exp(png_fixed_point x)
+{
+ if (x > 0 && x <= 0xfffff) /* Else overflow or zero (underflow) */
+ {
+ /* Obtain a 4-bit approximation */
+ png_uint_32 e = png_32bit_exp[(x >> 12) & 0x0f];
+
+ /* Incorporate the low 12 bits - these decrease the returned value by
+ * multiplying by a number less than 1 if the bit is set. The multiplier
+ * is determined by the above table and the shift. Notice that the values
+ * converge on 45426 and this is used to allow linear interpolation of the
+ * low bits.
+ */
+ if (x & 0x800)
+ e -= (((e >> 16) * 44938U) + 16U) >> 5;
+
+ if (x & 0x400)
+ e -= (((e >> 16) * 45181U) + 32U) >> 6;
+
+ if (x & 0x200)
+ e -= (((e >> 16) * 45303U) + 64U) >> 7;
+
+ if (x & 0x100)
+ e -= (((e >> 16) * 45365U) + 128U) >> 8;
+
+ if (x & 0x080)
+ e -= (((e >> 16) * 45395U) + 256U) >> 9;
+
+ if (x & 0x040)
+ e -= (((e >> 16) * 45410U) + 512U) >> 10;
+
+ /* And handle the low 6 bits in a single block. */
+ e -= (((e >> 16) * 355U * (x & 0x3fU)) + 256U) >> 9;
+
+ /* Handle the upper bits of x. */
+ e >>= x >> 16;
+ return e;
+ }
+
+ /* Check for overflow */
+ if (x <= 0)
+ return png_32bit_exp[0];
+
+ /* Else underflow */
+ return 0;
+}
+
+static png_byte
+png_exp8bit(png_fixed_point lg2)
+{
+ /* Get a 32-bit value: */
+ png_uint_32 x = png_exp(lg2);
+
+ /* Convert the 32-bit value to 0..255 by multiplying by 256-1. Note that the
+ * second, rounding, step can't overflow because of the first, subtraction,
+ * step.
+ */
+ x -= x >> 8;
+ return (png_byte)(((x + 0x7fffffU) >> 24) & 0xff);
+}
+
+#ifdef PNG_16BIT_SUPPORTED
+static png_uint_16
+png_exp16bit(png_fixed_point lg2)
+{
+ /* Get a 32-bit value: */
+ png_uint_32 x = png_exp(lg2);
+
+ /* Convert the 32-bit value to 0..65535 by multiplying by 65536-1: */
+ x -= x >> 16;
+ return (png_uint_16)((x + 32767U) >> 16);
+}
+#endif /* 16BIT */
+#endif /* FLOATING_ARITHMETIC */
+
+png_byte
+png_gamma_8bit_correct(unsigned int value, png_fixed_point gamma_val)
+{
+ if (value > 0 && value < 255)
+ {
+# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+ /* 'value' is unsigned, ANSI-C90 requires the compiler to correctly
+ * convert this to a floating point value. This includes values that
+ * would overflow if 'value' were to be converted to 'int'.
+ *
+ * Apparently GCC, however, does an intermediate conversion to (int)
+ * on some (ARM) but not all (x86) platforms, possibly because of
+ * hardware FP limitations. (E.g. if the hardware conversion always
+ * assumes the integer register contains a signed value.) This results
+ * in ANSI-C undefined behavior for large values.
+ *
+ * Other implementations on the same machine might actually be ANSI-C90
+ * conformant and therefore compile spurious extra code for the large
+ * values.
+ *
+ * We can be reasonably sure that an unsigned to float conversion
+ * won't be faster than an int to float one. Therefore this code
+ * assumes responsibility for the undefined behavior, which it knows
+ * can't happen because of the check above.
+ *
+ * Note the argument to this routine is an (unsigned int) because, on
+ * 16-bit platforms, it is assigned a value which might be out of
+ * range for an (int); that would result in undefined behavior in the
+ * caller if the *argument* ('value') were to be declared (int).
+ */
+ double r = floor(255*pow((int)/*SAFE*/value/255.,gamma_val*.00001)+.5);
+ return (png_byte)r;
+# else
+ png_int_32 lg2 = png_log8bit(value);
+ png_fixed_point res;
+
+ if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1) != 0)
+ return png_exp8bit(res);
+
+ /* Overflow. */
+ value = 0;
+# endif
+ }
+
+ return (png_byte)(value & 0xff);
+}
+
+#ifdef PNG_16BIT_SUPPORTED
+png_uint_16
+png_gamma_16bit_correct(unsigned int value, png_fixed_point gamma_val)
+{
+ if (value > 0 && value < 65535)
+ {
+# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+ /* The same (unsigned int)->(double) constraints apply here as above,
+ * however in this case the (unsigned int) to (int) conversion can
+ * overflow on an ANSI-C90 compliant system so the cast needs to ensure
+ * that this is not possible.
+ */
+ double r = floor(65535*pow((png_int_32)value/65535.,
+ gamma_val*.00001)+.5);
+ return (png_uint_16)r;
+# else
+ png_int_32 lg2 = png_log16bit(value);
+ png_fixed_point res;
+
+ if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1) != 0)
+ return png_exp16bit(res);
+
+ /* Overflow. */
+ value = 0;
+# endif
+ }
+
+ return (png_uint_16)value;
+}
+#endif /* 16BIT */
+
+/* This does the right thing based on the bit_depth field of the
+ * png_struct, interpreting values as 8-bit or 16-bit. While the result
+ * is nominally a 16-bit value if bit depth is 8 then the result is
+ * 8-bit (as are the arguments.)
+ */
+png_uint_16 /* PRIVATE */
+png_gamma_correct(png_structrp png_ptr, unsigned int value,
+ png_fixed_point gamma_val)
+{
+ if (png_ptr->bit_depth == 8)
+ return png_gamma_8bit_correct(value, gamma_val);
+
+#ifdef PNG_16BIT_SUPPORTED
+ else
+ return png_gamma_16bit_correct(value, gamma_val);
+#else
+ /* should not reach this */
+ return 0;
+#endif /* 16BIT */
+}
+
+#ifdef PNG_16BIT_SUPPORTED
+/* Internal function to build a single 16-bit table - the table consists of
+ * 'num' 256 entry subtables, where 'num' is determined by 'shift' - the amount
+ * to shift the input values right (or 16-number_of_signifiant_bits).
+ *
+ * The caller is responsible for ensuring that the table gets cleaned up on
+ * png_error (i.e. if one of the mallocs below fails) - i.e. the *table argument
+ * should be somewhere that will be cleaned.
+ */
+static void
+png_build_16bit_table(png_structrp png_ptr, png_uint_16pp *ptable,
+ unsigned int shift, png_fixed_point gamma_val)
+{
+ /* Various values derived from 'shift': */
+ unsigned int num = 1U << (8U - shift);
+#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+ /* CSE the division and work round wacky GCC warnings (see the comments
+ * in png_gamma_8bit_correct for where these come from.)
+ */
+ double fmax = 1.0 / (((png_int_32)1 << (16U - shift)) - 1);
+#endif
+ unsigned int max = (1U << (16U - shift)) - 1U;
+ unsigned int max_by_2 = 1U << (15U - shift);
+ unsigned int i;
+
+ png_uint_16pp table = *ptable =
+ (png_uint_16pp)png_calloc(png_ptr, num * (sizeof (png_uint_16p)));
+
+ for (i = 0; i < num; i++)
+ {
+ png_uint_16p sub_table = table[i] =
+ (png_uint_16p)png_malloc(png_ptr, 256 * (sizeof (png_uint_16)));
+
+ /* The 'threshold' test is repeated here because it can arise for one of
+ * the 16-bit tables even if the others don't hit it.
+ */
+ if (png_gamma_significant(gamma_val) != 0)
+ {
+ /* The old code would overflow at the end and this would cause the
+ * 'pow' function to return a result >1, resulting in an
+ * arithmetic error. This code follows the spec exactly; ig is
+ * the recovered input sample, it always has 8-16 bits.
+ *
+ * We want input * 65535/max, rounded, the arithmetic fits in 32
+ * bits (unsigned) so long as max <= 32767.
+ */
+ unsigned int j;
+ for (j = 0; j < 256; j++)
+ {
+ png_uint_32 ig = (j << (8-shift)) + i;
+# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+ /* Inline the 'max' scaling operation: */
+ /* See png_gamma_8bit_correct for why the cast to (int) is
+ * required here.
+ */
+ double d = floor(65535.*pow(ig*fmax, gamma_val*.00001)+.5);
+ sub_table[j] = (png_uint_16)d;
+# else
+ if (shift != 0)
+ ig = (ig * 65535U + max_by_2)/max;
+
+ sub_table[j] = png_gamma_16bit_correct(ig, gamma_val);
+# endif
+ }
+ }
+ else
+ {
+ /* We must still build a table, but do it the fast way. */
+ unsigned int j;
+
+ for (j = 0; j < 256; j++)
+ {
+ png_uint_32 ig = (j << (8-shift)) + i;
+
+ if (shift != 0)
+ ig = (ig * 65535U + max_by_2)/max;
+
+ sub_table[j] = (png_uint_16)ig;
+ }
+ }
+ }
+}
+
+/* NOTE: this function expects the *inverse* of the overall gamma transformation
+ * required.
+ */
+static void
+png_build_16to8_table(png_structrp png_ptr, png_uint_16pp *ptable,
+ unsigned int shift, png_fixed_point gamma_val)
+{
+ unsigned int num = 1U << (8U - shift);
+ unsigned int max = (1U << (16U - shift))-1U;
+ unsigned int i;
+ png_uint_32 last;
+
+ png_uint_16pp table = *ptable =
+ (png_uint_16pp)png_calloc(png_ptr, num * (sizeof (png_uint_16p)));
+
+ /* 'num' is the number of tables and also the number of low bits of low
+ * bits of the input 16-bit value used to select a table. Each table is
+ * itself indexed by the high 8 bits of the value.
+ */
+ for (i = 0; i < num; i++)
+ table[i] = (png_uint_16p)png_malloc(png_ptr,
+ 256 * (sizeof (png_uint_16)));
+
+ /* 'gamma_val' is set to the reciprocal of the value calculated above, so
+ * pow(out,g) is an *input* value. 'last' is the last input value set.
+ *
+ * In the loop 'i' is used to find output values. Since the output is
+ * 8-bit there are only 256 possible values. The tables are set up to
+ * select the closest possible output value for each input by finding
+ * the input value at the boundary between each pair of output values
+ * and filling the table up to that boundary with the lower output
+ * value.
+ *
+ * The boundary values are 0.5,1.5..253.5,254.5. Since these are 9-bit
+ * values the code below uses a 16-bit value in i; the values start at
+ * 128.5 (for 0.5) and step by 257, for a total of 254 values (the last
+ * entries are filled with 255). Start i at 128 and fill all 'last'
+ * table entries <= 'max'
+ */
+ last = 0;
+ for (i = 0; i < 255; ++i) /* 8-bit output value */
+ {
+ /* Find the corresponding maximum input value */
+ png_uint_16 out = (png_uint_16)(i * 257U); /* 16-bit output value */
+
+ /* Find the boundary value in 16 bits: */
+ png_uint_32 bound = png_gamma_16bit_correct(out+128U, gamma_val);
+
+ /* Adjust (round) to (16-shift) bits: */
+ bound = (bound * max + 32768U)/65535U + 1U;
+
+ while (last < bound)
+ {
+ table[last & (0xffU >> shift)][last >> (8U - shift)] = out;
+ last++;
+ }
+ }
+
+ /* And fill in the final entries. */
+ while (last < (num << 8))
+ {
+ table[last & (0xff >> shift)][last >> (8U - shift)] = 65535U;
+ last++;
+ }
+}
+#endif /* 16BIT */
+
+/* Build a single 8-bit table: same as the 16-bit case but much simpler (and
+ * typically much faster). Note that libpng currently does no sBIT processing
+ * (apparently contrary to the spec) so a 256-entry table is always generated.
+ */
+static void
+png_build_8bit_table(png_structrp png_ptr, png_bytepp ptable,
+ png_fixed_point gamma_val)
+{
+ unsigned int i;
+ png_bytep table = *ptable = (png_bytep)png_malloc(png_ptr, 256);
+
+ if (png_gamma_significant(gamma_val) != 0)
+ for (i=0; i<256; i++)
+ table[i] = png_gamma_8bit_correct(i, gamma_val);
+
+ else
+ for (i=0; i<256; ++i)
+ table[i] = (png_byte)(i & 0xff);
+}
+
+/* Used from png_read_destroy and below to release the memory used by the gamma
+ * tables.
+ */
+void /* PRIVATE */
+png_destroy_gamma_table(png_structrp png_ptr)
+{
+ png_free(png_ptr, png_ptr->gamma_table);
+ png_ptr->gamma_table = NULL;
+
+#ifdef PNG_16BIT_SUPPORTED
+ if (png_ptr->gamma_16_table != NULL)
+ {
+ int i;
+ int istop = (1 << (8 - png_ptr->gamma_shift));
+ for (i = 0; i < istop; i++)
+ {
+ png_free(png_ptr, png_ptr->gamma_16_table[i]);
+ }
+ png_free(png_ptr, png_ptr->gamma_16_table);
+ png_ptr->gamma_16_table = NULL;
+ }
+#endif /* 16BIT */
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+ defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
+ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+ png_free(png_ptr, png_ptr->gamma_from_1);
+ png_ptr->gamma_from_1 = NULL;
+ png_free(png_ptr, png_ptr->gamma_to_1);
+ png_ptr->gamma_to_1 = NULL;
+
+#ifdef PNG_16BIT_SUPPORTED
+ if (png_ptr->gamma_16_from_1 != NULL)
+ {
+ int i;
+ int istop = (1 << (8 - png_ptr->gamma_shift));
+ for (i = 0; i < istop; i++)
+ {
+ png_free(png_ptr, png_ptr->gamma_16_from_1[i]);
+ }
+ png_free(png_ptr, png_ptr->gamma_16_from_1);
+ png_ptr->gamma_16_from_1 = NULL;
+ }
+ if (png_ptr->gamma_16_to_1 != NULL)
+ {
+ int i;
+ int istop = (1 << (8 - png_ptr->gamma_shift));
+ for (i = 0; i < istop; i++)
+ {
+ png_free(png_ptr, png_ptr->gamma_16_to_1[i]);
+ }
+ png_free(png_ptr, png_ptr->gamma_16_to_1);
+ png_ptr->gamma_16_to_1 = NULL;
+ }
+#endif /* 16BIT */
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
+}
+
+/* We build the 8- or 16-bit gamma tables here. Note that for 16-bit
+ * tables, we don't make a full table if we are reducing to 8-bit in
+ * the future. Note also how the gamma_16 tables are segmented so that
+ * we don't need to allocate > 64K chunks for a full 16-bit table.
+ *
+ * TODO: move this to pngrtran.c and make it static. Better yet create
+ * pngcolor.c and put all the PNG_COLORSPACE stuff in there.
+ */
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+ defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
+ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+# define GAMMA_TRANSFORMS 1 /* #ifdef CSE */
+#else
+# define GAMMA_TRANSFORMS 0
+#endif
+
+void /* PRIVATE */
+png_build_gamma_table(png_structrp png_ptr, int bit_depth)
+{
+ png_fixed_point file_gamma, screen_gamma;
+ png_fixed_point correction;
+# if GAMMA_TRANSFORMS
+ png_fixed_point file_to_linear, linear_to_screen;
+# endif
+
+ png_debug(1, "in png_build_gamma_table");
+
+ /* Remove any existing table; this copes with multiple calls to
+ * png_read_update_info. The warning is because building the gamma tables
+ * multiple times is a performance hit - it's harmless but the ability to
+ * call png_read_update_info() multiple times is new in 1.5.6 so it seems
+ * sensible to warn if the app introduces such a hit.
+ */
+ if (png_ptr->gamma_table != NULL || png_ptr->gamma_16_table != NULL)
+ {
+ png_warning(png_ptr, "gamma table being rebuilt");
+ png_destroy_gamma_table(png_ptr);
+ }
+
+ /* The following fields are set, finally, in png_init_read_transformations.
+ * If file_gamma is 0 (unset) nothing can be done otherwise if screen_gamma
+ * is 0 (unset) there is no gamma correction but to/from linear is possible.
+ */
+ file_gamma = png_ptr->file_gamma;
+ screen_gamma = png_ptr->screen_gamma;
+# if GAMMA_TRANSFORMS
+ file_to_linear = png_reciprocal(file_gamma);
+# endif
+
+ if (screen_gamma > 0)
+ {
+# if GAMMA_TRANSFORMS
+ linear_to_screen = png_reciprocal(screen_gamma);
+# endif
+ correction = png_reciprocal2(screen_gamma, file_gamma);
+ }
+ else /* screen gamma unknown */
+ {
+# if GAMMA_TRANSFORMS
+ linear_to_screen = file_gamma;
+# endif
+ correction = PNG_FP_1;
+ }
+
+ if (bit_depth <= 8)
+ {
+ png_build_8bit_table(png_ptr, &png_ptr->gamma_table, correction);
+
+#if GAMMA_TRANSFORMS
+ if ((png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) != 0)
+ {
+ png_build_8bit_table(png_ptr, &png_ptr->gamma_to_1, file_to_linear);
+
+ png_build_8bit_table(png_ptr, &png_ptr->gamma_from_1,
+ linear_to_screen);
+ }
+#endif /* GAMMA_TRANSFORMS */
+ }
+#ifdef PNG_16BIT_SUPPORTED
+ else
+ {
+ png_byte shift, sig_bit;
+
+ if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ {
+ sig_bit = png_ptr->sig_bit.red;
+
+ if (png_ptr->sig_bit.green > sig_bit)
+ sig_bit = png_ptr->sig_bit.green;
+
+ if (png_ptr->sig_bit.blue > sig_bit)
+ sig_bit = png_ptr->sig_bit.blue;
+ }
+ else
+ sig_bit = png_ptr->sig_bit.gray;
+
+ /* 16-bit gamma code uses this equation:
+ *
+ * ov = table[(iv & 0xff) >> gamma_shift][iv >> 8]
+ *
+ * Where 'iv' is the input color value and 'ov' is the output value -
+ * pow(iv, gamma).
+ *
+ * Thus the gamma table consists of up to 256 256-entry tables. The table
+ * is selected by the (8-gamma_shift) most significant of the low 8 bits
+ * of the color value then indexed by the upper 8 bits:
+ *
+ * table[low bits][high 8 bits]
+ *
+ * So the table 'n' corresponds to all those 'iv' of:
+ *
+ * ..<(n+1 << gamma_shift)-1>
+ *
+ */
+ if (sig_bit > 0 && sig_bit < 16U)
+ /* shift == insignificant bits */
+ shift = (png_byte)((16U - sig_bit) & 0xff);
+
+ else
+ shift = 0; /* keep all 16 bits */
+
+ if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) != 0)
+ {
+ /* PNG_MAX_GAMMA_8 is the number of bits to keep - effectively
+ * the significant bits in the *input* when the output will
+ * eventually be 8 bits. By default it is 11.
+ */
+ if (shift < (16U - PNG_MAX_GAMMA_8))
+ shift = (16U - PNG_MAX_GAMMA_8);
+ }
+
+ if (shift > 8U)
+ shift = 8U; /* Guarantees at least one table! */
+
+ png_ptr->gamma_shift = shift;
+
+ /* NOTE: prior to 1.5.4 this test used to include PNG_BACKGROUND (now
+ * PNG_COMPOSE). This effectively smashed the background calculation for
+ * 16-bit output because the 8-bit table assumes the result will be
+ * reduced to 8 bits.
+ */
+ if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) != 0)
+ png_build_16to8_table(png_ptr, &png_ptr->gamma_16_table, shift,
+ png_reciprocal(correction));
+ else
+ png_build_16bit_table(png_ptr, &png_ptr->gamma_16_table, shift,
+ correction);
+
+# if GAMMA_TRANSFORMS
+ if ((png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) != 0)
+ {
+ png_build_16bit_table(png_ptr, &png_ptr->gamma_16_to_1, shift,
+ file_to_linear);
+
+ /* Notice that the '16 from 1' table should be full precision, however
+ * the lookup on this table still uses gamma_shift, so it can't be.
+ * TODO: fix this.
+ */
+ png_build_16bit_table(png_ptr, &png_ptr->gamma_16_from_1, shift,
+ linear_to_screen);
+ }
+#endif /* GAMMA_TRANSFORMS */
+ }
+#endif /* 16BIT */
+}
+#endif /* READ_GAMMA */
+
+/* HARDWARE OR SOFTWARE OPTION SUPPORT */
+#ifdef PNG_SET_OPTION_SUPPORTED
+int PNGAPI
+png_set_option(png_structrp png_ptr, int option, int onoff)
+{
+ if (png_ptr != NULL && option >= 0 && option < PNG_OPTION_NEXT &&
+ (option & 1) == 0)
+ {
+ png_uint_32 mask = 3U << option;
+ png_uint_32 setting = (2U + (onoff != 0)) << option;
+ png_uint_32 current = png_ptr->options;
+
+ png_ptr->options = (png_uint_32)((current & ~mask) | setting);
+
+ return (int)(current & mask) >> option;
+ }
+
+ return PNG_OPTION_INVALID;
+}
+#endif
+
+/* sRGB support */
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
+ defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+/* sRGB conversion tables; these are machine generated with the code in
+ * contrib/tools/makesRGB.c. The actual sRGB transfer curve defined in the
+ * specification (see the article at https://en.wikipedia.org/wiki/SRGB)
+ * is used, not the gamma=1/2.2 approximation use elsewhere in libpng.
+ * The sRGB to linear table is exact (to the nearest 16-bit linear fraction).
+ * The inverse (linear to sRGB) table has accuracies as follows:
+ *
+ * For all possible (255*65535+1) input values:
+ *
+ * error: -0.515566 - 0.625971, 79441 (0.475369%) of readings inexact
+ *
+ * For the input values corresponding to the 65536 16-bit values:
+ *
+ * error: -0.513727 - 0.607759, 308 (0.469978%) of readings inexact
+ *
+ * In all cases the inexact readings are only off by one.
+ */
+
+#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
+/* The convert-to-sRGB table is only currently required for read. */
+const png_uint_16 png_sRGB_table[256] =
+{
+ 0,20,40,60,80,99,119,139,
+ 159,179,199,219,241,264,288,313,
+ 340,367,396,427,458,491,526,562,
+ 599,637,677,718,761,805,851,898,
+ 947,997,1048,1101,1156,1212,1270,1330,
+ 1391,1453,1517,1583,1651,1720,1790,1863,
+ 1937,2013,2090,2170,2250,2333,2418,2504,
+ 2592,2681,2773,2866,2961,3058,3157,3258,
+ 3360,3464,3570,3678,3788,3900,4014,4129,
+ 4247,4366,4488,4611,4736,4864,4993,5124,
+ 5257,5392,5530,5669,5810,5953,6099,6246,
+ 6395,6547,6700,6856,7014,7174,7335,7500,
+ 7666,7834,8004,8177,8352,8528,8708,8889,
+ 9072,9258,9445,9635,9828,10022,10219,10417,
+ 10619,10822,11028,11235,11446,11658,11873,12090,
+ 12309,12530,12754,12980,13209,13440,13673,13909,
+ 14146,14387,14629,14874,15122,15371,15623,15878,
+ 16135,16394,16656,16920,17187,17456,17727,18001,
+ 18277,18556,18837,19121,19407,19696,19987,20281,
+ 20577,20876,21177,21481,21787,22096,22407,22721,
+ 23038,23357,23678,24002,24329,24658,24990,25325,
+ 25662,26001,26344,26688,27036,27386,27739,28094,
+ 28452,28813,29176,29542,29911,30282,30656,31033,
+ 31412,31794,32179,32567,32957,33350,33745,34143,
+ 34544,34948,35355,35764,36176,36591,37008,37429,
+ 37852,38278,38706,39138,39572,40009,40449,40891,
+ 41337,41785,42236,42690,43147,43606,44069,44534,
+ 45002,45473,45947,46423,46903,47385,47871,48359,
+ 48850,49344,49841,50341,50844,51349,51858,52369,
+ 52884,53401,53921,54445,54971,55500,56032,56567,
+ 57105,57646,58190,58737,59287,59840,60396,60955,
+ 61517,62082,62650,63221,63795,64372,64952,65535
+};
+#endif /* SIMPLIFIED_READ */
+
+/* The base/delta tables are required for both read and write (but currently
+ * only the simplified versions.)
+ */
+const png_uint_16 png_sRGB_base[512] =
+{
+ 128,1782,3383,4644,5675,6564,7357,8074,
+ 8732,9346,9921,10463,10977,11466,11935,12384,
+ 12816,13233,13634,14024,14402,14769,15125,15473,
+ 15812,16142,16466,16781,17090,17393,17690,17981,
+ 18266,18546,18822,19093,19359,19621,19879,20133,
+ 20383,20630,20873,21113,21349,21583,21813,22041,
+ 22265,22487,22707,22923,23138,23350,23559,23767,
+ 23972,24175,24376,24575,24772,24967,25160,25352,
+ 25542,25730,25916,26101,26284,26465,26645,26823,
+ 27000,27176,27350,27523,27695,27865,28034,28201,
+ 28368,28533,28697,28860,29021,29182,29341,29500,
+ 29657,29813,29969,30123,30276,30429,30580,30730,
+ 30880,31028,31176,31323,31469,31614,31758,31902,
+ 32045,32186,32327,32468,32607,32746,32884,33021,
+ 33158,33294,33429,33564,33697,33831,33963,34095,
+ 34226,34357,34486,34616,34744,34873,35000,35127,
+ 35253,35379,35504,35629,35753,35876,35999,36122,
+ 36244,36365,36486,36606,36726,36845,36964,37083,
+ 37201,37318,37435,37551,37668,37783,37898,38013,
+ 38127,38241,38354,38467,38580,38692,38803,38915,
+ 39026,39136,39246,39356,39465,39574,39682,39790,
+ 39898,40005,40112,40219,40325,40431,40537,40642,
+ 40747,40851,40955,41059,41163,41266,41369,41471,
+ 41573,41675,41777,41878,41979,42079,42179,42279,
+ 42379,42478,42577,42676,42775,42873,42971,43068,
+ 43165,43262,43359,43456,43552,43648,43743,43839,
+ 43934,44028,44123,44217,44311,44405,44499,44592,
+ 44685,44778,44870,44962,45054,45146,45238,45329,
+ 45420,45511,45601,45692,45782,45872,45961,46051,
+ 46140,46229,46318,46406,46494,46583,46670,46758,
+ 46846,46933,47020,47107,47193,47280,47366,47452,
+ 47538,47623,47709,47794,47879,47964,48048,48133,
+ 48217,48301,48385,48468,48552,48635,48718,48801,
+ 48884,48966,49048,49131,49213,49294,49376,49458,
+ 49539,49620,49701,49782,49862,49943,50023,50103,
+ 50183,50263,50342,50422,50501,50580,50659,50738,
+ 50816,50895,50973,51051,51129,51207,51285,51362,
+ 51439,51517,51594,51671,51747,51824,51900,51977,
+ 52053,52129,52205,52280,52356,52432,52507,52582,
+ 52657,52732,52807,52881,52956,53030,53104,53178,
+ 53252,53326,53400,53473,53546,53620,53693,53766,
+ 53839,53911,53984,54056,54129,54201,54273,54345,
+ 54417,54489,54560,54632,54703,54774,54845,54916,
+ 54987,55058,55129,55199,55269,55340,55410,55480,
+ 55550,55620,55689,55759,55828,55898,55967,56036,
+ 56105,56174,56243,56311,56380,56448,56517,56585,
+ 56653,56721,56789,56857,56924,56992,57059,57127,
+ 57194,57261,57328,57395,57462,57529,57595,57662,
+ 57728,57795,57861,57927,57993,58059,58125,58191,
+ 58256,58322,58387,58453,58518,58583,58648,58713,
+ 58778,58843,58908,58972,59037,59101,59165,59230,
+ 59294,59358,59422,59486,59549,59613,59677,59740,
+ 59804,59867,59930,59993,60056,60119,60182,60245,
+ 60308,60370,60433,60495,60558,60620,60682,60744,
+ 60806,60868,60930,60992,61054,61115,61177,61238,
+ 61300,61361,61422,61483,61544,61605,61666,61727,
+ 61788,61848,61909,61969,62030,62090,62150,62211,
+ 62271,62331,62391,62450,62510,62570,62630,62689,
+ 62749,62808,62867,62927,62986,63045,63104,63163,
+ 63222,63281,63340,63398,63457,63515,63574,63632,
+ 63691,63749,63807,63865,63923,63981,64039,64097,
+ 64155,64212,64270,64328,64385,64443,64500,64557,
+ 64614,64672,64729,64786,64843,64900,64956,65013,
+ 65070,65126,65183,65239,65296,65352,65409,65465
+};
+
+const png_byte png_sRGB_delta[512] =
+{
+ 207,201,158,129,113,100,90,82,77,72,68,64,61,59,56,54,
+ 52,50,49,47,46,45,43,42,41,40,39,39,38,37,36,36,
+ 35,34,34,33,33,32,32,31,31,30,30,30,29,29,28,28,
+ 28,27,27,27,27,26,26,26,25,25,25,25,24,24,24,24,
+ 23,23,23,23,23,22,22,22,22,22,22,21,21,21,21,21,
+ 21,20,20,20,20,20,20,20,20,19,19,19,19,19,19,19,
+ 19,18,18,18,18,18,18,18,18,18,18,17,17,17,17,17,
+ 17,17,17,17,17,17,16,16,16,16,16,16,16,16,16,16,
+ 16,16,16,16,15,15,15,15,15,15,15,15,15,15,15,15,
+ 15,15,15,15,14,14,14,14,14,14,14,14,14,14,14,14,
+ 14,14,14,14,14,14,14,13,13,13,13,13,13,13,13,13,
+ 13,13,13,13,13,13,13,13,13,13,13,13,13,13,12,12,
+ 12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,
+ 12,12,12,12,12,12,12,12,12,12,12,12,11,11,11,11,
+ 11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,
+ 11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,
+ 11,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,
+ 10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,
+ 10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,
+ 10,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
+ 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
+ 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
+ 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
+ 9,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+ 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+ 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+ 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+ 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+ 8,8,8,8,8,8,8,8,8,7,7,7,7,7,7,7,
+ 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+ 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+ 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
+};
+#endif /* SIMPLIFIED READ/WRITE sRGB support */
+
+/* SIMPLIFIED READ/WRITE SUPPORT */
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
+ defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+static int
+png_image_free_function(png_voidp argument)
+{
+ png_imagep image = png_voidcast(png_imagep, argument);
+ png_controlp cp = image->opaque;
+ png_control c;
+
+ /* Double check that we have a png_ptr - it should be impossible to get here
+ * without one.
+ */
+ if (cp->png_ptr == NULL)
+ return 0;
+
+ /* First free any data held in the control structure. */
+# ifdef PNG_STDIO_SUPPORTED
+ if (cp->owned_file != 0)
+ {
+ FILE *fp = png_voidcast(FILE *, cp->png_ptr->io_ptr);
+ cp->owned_file = 0;
+
+ /* Ignore errors here. */
+ if (fp != NULL)
+ {
+ cp->png_ptr->io_ptr = NULL;
+ (void)fclose(fp);
+ }
+ }
+# endif
+
+ /* Copy the control structure so that the original, allocated, version can be
+ * safely freed. Notice that a png_error here stops the remainder of the
+ * cleanup, but this is probably fine because that would indicate bad memory
+ * problems anyway.
+ */
+ c = *cp;
+ image->opaque = &c;
+ png_free(c.png_ptr, cp);
+
+ /* Then the structures, calling the correct API. */
+ if (c.for_write != 0)
+ {
+# ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
+ png_destroy_write_struct(&c.png_ptr, &c.info_ptr);
+# else
+ png_error(c.png_ptr, "simplified write not supported");
+# endif
+ }
+ else
+ {
+# ifdef PNG_SIMPLIFIED_READ_SUPPORTED
+ png_destroy_read_struct(&c.png_ptr, &c.info_ptr, NULL);
+# else
+ png_error(c.png_ptr, "simplified read not supported");
+# endif
+ }
+
+ /* Success. */
+ return 1;
+}
+
+void PNGAPI
+png_image_free(png_imagep image)
+{
+ /* Safely call the real function, but only if doing so is safe at this point
+ * (if not inside an error handling context). Otherwise assume
+ * png_safe_execute will call this API after the return.
+ */
+ if (image != NULL && image->opaque != NULL &&
+ image->opaque->error_buf == NULL)
+ {
+ png_image_free_function(image);
+ image->opaque = NULL;
+ }
+}
+
+int /* PRIVATE */
+png_image_error(png_imagep image, png_const_charp error_message)
+{
+ /* Utility to log an error. */
+ png_safecat(image->message, (sizeof image->message), 0, error_message);
+ image->warning_or_error |= PNG_IMAGE_ERROR;
+ png_image_free(image);
+ return 0;
+}
+
+#endif /* SIMPLIFIED READ/WRITE */
+#endif /* READ || WRITE */
diff --git a/libs/imagequant/external/libpng/png.h b/libs/imagequant/external/libpng/png.h
new file mode 100644
index 00000000..7f9c0dcd
--- /dev/null
+++ b/libs/imagequant/external/libpng/png.h
@@ -0,0 +1,3362 @@
+/* png.h - header file for PNG reference library
+ *
+ * libpng version 1.6.49.git
+ *
+ * Copyright (c) 2018-2025 Cosmin Truta
+ * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * This code is released under the libpng license. (See LICENSE, below.)
+ *
+ * Authors and maintainers:
+ * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
+ * libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
+ * libpng versions 0.97, January 1998, through 1.6.35, July 2018:
+ * Glenn Randers-Pehrson
+ * libpng versions 1.6.36, December 2018, through 1.6.48, April 2025:
+ * Cosmin Truta
+ * See also "Contributing Authors", below.
+ */
+
+/*
+ * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE
+ * =========================================
+ *
+ * PNG Reference Library License version 2
+ * ---------------------------------------
+ *
+ * * Copyright (c) 1995-2025 The PNG Reference Library Authors.
+ * * Copyright (c) 2018-2025 Cosmin Truta.
+ * * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson.
+ * * Copyright (c) 1996-1997 Andreas Dilger.
+ * * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * The software is supplied "as is", without warranty of any kind,
+ * express or implied, including, without limitation, the warranties
+ * of merchantability, fitness for a particular purpose, title, and
+ * non-infringement. In no event shall the Copyright owners, or
+ * anyone distributing the software, be liable for any damages or
+ * other liability, whether in contract, tort or otherwise, arising
+ * from, out of, or in connection with the software, or the use or
+ * other dealings in the software, even if advised of the possibility
+ * of such damage.
+ *
+ * Permission is hereby granted to use, copy, modify, and distribute
+ * this software, or portions hereof, for any purpose, without fee,
+ * subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you
+ * must not claim that you wrote the original software. If you
+ * use this software in a product, an acknowledgment in the product
+ * documentation would be appreciated, but is not required.
+ *
+ * 2. Altered source versions must be plainly marked as such, and must
+ * not be misrepresented as being the original software.
+ *
+ * 3. This Copyright notice may not be removed or altered from any
+ * source or altered source distribution.
+ *
+ *
+ * PNG Reference Library License version 1 (for libpng 0.5 through 1.6.35)
+ * -----------------------------------------------------------------------
+ *
+ * libpng versions 1.0.7, July 1, 2000, through 1.6.35, July 15, 2018 are
+ * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson, are
+ * derived from libpng-1.0.6, and are distributed according to the same
+ * disclaimer and license as libpng-1.0.6 with the following individuals
+ * added to the list of Contributing Authors:
+ *
+ * Simon-Pierre Cadieux
+ * Eric S. Raymond
+ * Mans Rullgard
+ * Cosmin Truta
+ * Gilles Vollant
+ * James Yu
+ * Mandar Sahastrabuddhe
+ * Google Inc.
+ * Vadim Barkov
+ *
+ * and with the following additions to the disclaimer:
+ *
+ * There is no warranty against interference with your enjoyment of
+ * the library or against infringement. There is no warranty that our
+ * efforts or the library will fulfill any of your particular purposes
+ * or needs. This library is provided with all faults, and the entire
+ * risk of satisfactory quality, performance, accuracy, and effort is
+ * with the user.
+ *
+ * Some files in the "contrib" directory and some configure-generated
+ * files that are distributed with libpng have other copyright owners, and
+ * are released under other open source licenses.
+ *
+ * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
+ * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
+ * libpng-0.96, and are distributed according to the same disclaimer and
+ * license as libpng-0.96, with the following individuals added to the
+ * list of Contributing Authors:
+ *
+ * Tom Lane
+ * Glenn Randers-Pehrson
+ * Willem van Schaik
+ *
+ * libpng versions 0.89, June 1996, through 0.96, May 1997, are
+ * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
+ * and are distributed according to the same disclaimer and license as
+ * libpng-0.88, with the following individuals added to the list of
+ * Contributing Authors:
+ *
+ * John Bowler
+ * Kevin Bracey
+ * Sam Bushell
+ * Magnus Holmgren
+ * Greg Roelofs
+ * Tom Tanner
+ *
+ * Some files in the "scripts" directory have other copyright owners,
+ * but are released under this license.
+ *
+ * libpng versions 0.5, May 1995, through 0.88, January 1996, are
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * For the purposes of this copyright and license, "Contributing Authors"
+ * is defined as the following set of individuals:
+ *
+ * Andreas Dilger
+ * Dave Martindale
+ * Guy Eric Schalnat
+ * Paul Schmidt
+ * Tim Wegner
+ *
+ * The PNG Reference Library is supplied "AS IS". The Contributing
+ * Authors and Group 42, Inc. disclaim all warranties, expressed or
+ * implied, including, without limitation, the warranties of
+ * merchantability and of fitness for any purpose. The Contributing
+ * Authors and Group 42, Inc. assume no liability for direct, indirect,
+ * incidental, special, exemplary, or consequential damages, which may
+ * result from the use of the PNG Reference Library, even if advised of
+ * the possibility of such damage.
+ *
+ * Permission is hereby granted to use, copy, modify, and distribute this
+ * source code, or portions hereof, for any purpose, without fee, subject
+ * to the following restrictions:
+ *
+ * 1. The origin of this source code must not be misrepresented.
+ *
+ * 2. Altered versions must be plainly marked as such and must not
+ * be misrepresented as being the original source.
+ *
+ * 3. This Copyright notice may not be removed or altered from any
+ * source or altered source distribution.
+ *
+ * The Contributing Authors and Group 42, Inc. specifically permit,
+ * without fee, and encourage the use of this source code as a component
+ * to supporting the PNG file format in commercial products. If you use
+ * this source code in a product, acknowledgment is not required but would
+ * be appreciated.
+ *
+ * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
+ *
+ * TRADEMARK
+ * =========
+ *
+ * The name "libpng" has not been registered by the Copyright owners
+ * as a trademark in any jurisdiction. However, because libpng has
+ * been distributed and maintained world-wide, continually since 1995,
+ * the Copyright owners claim "common-law trademark protection" in any
+ * jurisdiction where common-law trademark is recognized.
+ */
+
+/*
+ * A "png_get_copyright" function is available, for convenient use in "about"
+ * boxes and the like:
+ *
+ * printf("%s", png_get_copyright(NULL));
+ *
+ * Also, the PNG logo (in PNG format, of course) is supplied in the
+ * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
+ */
+
+/*
+ * The contributing authors would like to thank all those who helped
+ * with testing, bug fixes, and patience. This wouldn't have been
+ * possible without all of you.
+ *
+ * Thanks to Frank J. T. Wojcik for helping with the documentation.
+ */
+
+/* Note about libpng version numbers:
+ *
+ * Due to various miscommunications, unforeseen code incompatibilities
+ * and occasional factors outside the authors' control, version numbering
+ * on the library has not always been consistent and straightforward.
+ * The following table summarizes matters since version 0.89c, which was
+ * the first widely used release:
+ *
+ * source png.h png.h shared-lib
+ * version string int version
+ * ------- ------ ----- ----------
+ * 0.89c "1.0 beta 3" 0.89 89 1.0.89
+ * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
+ * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
+ * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
+ * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
+ * 0.97c 0.97 97 2.0.97
+ * 0.98 0.98 98 2.0.98
+ * 0.99 0.99 98 2.0.99
+ * 0.99a-m 0.99 99 2.0.99
+ * 1.00 1.00 100 2.1.0 [100 should be 10000]
+ * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
+ * 1.0.1 png.h string is 10001 2.1.0
+ * 1.0.1a-e identical to the 10002 from here on, the shared library
+ * 1.0.2 source version) 10002 is 2.V where V is the source code
+ * 1.0.2a-b 10003 version, except as noted.
+ * 1.0.3 10003
+ * 1.0.3a-d 10004
+ * 1.0.4 10004
+ * 1.0.4a-f 10005
+ * 1.0.5 (+ 2 patches) 10005
+ * 1.0.5a-d 10006
+ * 1.0.5e-r 10100 (not source compatible)
+ * 1.0.5s-v 10006 (not binary compatible)
+ * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
+ * 1.0.6d-f 10007 (still binary incompatible)
+ * 1.0.6g 10007
+ * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
+ * 1.0.6i 10007 10.6i
+ * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
+ * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
+ * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
+ * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
+ * 1.0.7 1 10007 (still compatible)
+ * ...
+ * 1.0.69 10 10069 10.so.0.69[.0]
+ * ...
+ * 1.2.59 13 10259 12.so.0.59[.0]
+ * ...
+ * 1.4.20 14 10420 14.so.0.20[.0]
+ * ...
+ * 1.5.30 15 10530 15.so.15.30[.0]
+ * ...
+ * 1.6.48 16 10648 16.so.16.48[.0]
+ *
+ * Henceforth the source version will match the shared-library major and
+ * minor numbers; the shared-library major version number will be used for
+ * changes in backward compatibility, as it is intended.
+ * The PNG_LIBPNG_VER macro, which is not used within libpng but is
+ * available for applications, is an unsigned integer of the form XYYZZ
+ * corresponding to the source version X.Y.Z (leading zeros in Y and Z).
+ * Beta versions were given the previous public release number plus a
+ * letter, until version 1.0.6j; from then on they were given the upcoming
+ * public release number plus "betaNN" or "rcNN".
+ *
+ * Binary incompatibility exists only when applications make direct access
+ * to the info_ptr or png_ptr members through png.h, and the compiled
+ * application is loaded with a different version of the library.
+ *
+ * See libpng.txt or libpng.3 for more information. The PNG specification
+ * is available as a W3C Recommendation and as an ISO/IEC Standard; see
+ *
+ */
+
+#ifndef PNG_H
+#define PNG_H
+
+/* This is not the place to learn how to use libpng. The file libpng-manual.txt
+ * describes how to use libpng, and the file example.c summarizes it
+ * with some code on which to build. This file is useful for looking
+ * at the actual function definitions and structure components. If that
+ * file has been stripped from your copy of libpng, you can find it at
+ *
+ *
+ * If you just need to read a PNG file and don't want to read the documentation
+ * skip to the end of this file and read the section entitled 'simplified API'.
+ */
+
+/* Version information for png.h - this should match the version in png.c */
+#define PNG_LIBPNG_VER_STRING "1.6.49.git"
+#define PNG_HEADER_VERSION_STRING " libpng version " PNG_LIBPNG_VER_STRING "\n"
+
+/* The versions of shared library builds should stay in sync, going forward */
+#define PNG_LIBPNG_VER_SHAREDLIB 16
+#define PNG_LIBPNG_VER_SONUM PNG_LIBPNG_VER_SHAREDLIB /* [Deprecated] */
+#define PNG_LIBPNG_VER_DLLNUM PNG_LIBPNG_VER_SHAREDLIB /* [Deprecated] */
+
+/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
+#define PNG_LIBPNG_VER_MAJOR 1
+#define PNG_LIBPNG_VER_MINOR 6
+#define PNG_LIBPNG_VER_RELEASE 49
+
+/* This should be zero for a public release, or non-zero for a
+ * development version.
+ */
+#define PNG_LIBPNG_VER_BUILD 1
+
+/* Release Status */
+#define PNG_LIBPNG_BUILD_ALPHA 1
+#define PNG_LIBPNG_BUILD_BETA 2
+#define PNG_LIBPNG_BUILD_RC 3
+#define PNG_LIBPNG_BUILD_STABLE 4
+#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
+
+/* Release-Specific Flags */
+#define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
+ PNG_LIBPNG_BUILD_STABLE only */
+#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
+ PNG_LIBPNG_BUILD_SPECIAL */
+#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
+ PNG_LIBPNG_BUILD_PRIVATE */
+
+#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_BETA
+
+/* Careful here. At one time, Guy wanted to use 082, but that
+ * would be octal. We must not include leading zeros.
+ * Versions 0.7 through 1.0.0 were in the range 0 to 100 here
+ * (only version 1.0.0 was mis-numbered 100 instead of 10000).
+ * From version 1.0.1 it is:
+ * XXYYZZ, where XX=major, YY=minor, ZZ=release
+ */
+#define PNG_LIBPNG_VER 10649 /* 1.6.49.git */
+
+/* Library configuration: these options cannot be changed after
+ * the library has been built.
+ */
+#ifndef PNGLCONF_H
+/* If pnglibconf.h is missing, you can
+ * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
+ */
+# include "pnglibconf.h"
+#endif
+
+#ifndef PNG_VERSION_INFO_ONLY
+/* Machine specific configuration. */
+# include "pngconf.h"
+#endif
+
+/*
+ * Added at libpng-1.2.8
+ *
+ * Ref MSDN: Private as priority over Special
+ * VS_FF_PRIVATEBUILD File *was not* built using standard release
+ * procedures. If this value is given, the StringFileInfo block must
+ * contain a PrivateBuild string.
+ *
+ * VS_FF_SPECIALBUILD File *was* built by the original company using
+ * standard release procedures but is a variation of the standard
+ * file of the same version number. If this value is given, the
+ * StringFileInfo block must contain a SpecialBuild string.
+ */
+
+#ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */
+# define PNG_LIBPNG_BUILD_TYPE \
+ (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
+#else
+# ifdef PNG_LIBPNG_SPECIALBUILD
+# define PNG_LIBPNG_BUILD_TYPE \
+ (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
+# else
+# define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
+# endif
+#endif
+
+#ifndef PNG_VERSION_INFO_ONLY
+
+/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+/* Version information for C files, stored in png.c. This had better match
+ * the version above.
+ */
+#define png_libpng_ver png_get_header_ver(NULL)
+
+/* This file is arranged in several sections:
+ *
+ * 1. [omitted]
+ * 2. Any configuration options that can be specified by for the application
+ * code when it is built. (Build time configuration is in pnglibconf.h)
+ * 3. Type definitions (base types are defined in pngconf.h), structure
+ * definitions.
+ * 4. Exported library functions.
+ * 5. Simplified API.
+ * 6. Implementation options.
+ *
+ * The library source code has additional files (principally pngpriv.h) that
+ * allow configuration of the library.
+ */
+
+/* Section 1: [omitted] */
+
+/* Section 2: run time configuration
+ * See pnglibconf.h for build time configuration
+ *
+ * Run time configuration allows the application to choose between
+ * implementations of certain arithmetic APIs. The default is set
+ * at build time and recorded in pnglibconf.h, but it is safe to
+ * override these (and only these) settings. Note that this won't
+ * change what the library does, only application code, and the
+ * settings can (and probably should) be made on a per-file basis
+ * by setting the #defines before including png.h
+ *
+ * Use macros to read integers from PNG data or use the exported
+ * functions?
+ * PNG_USE_READ_MACROS: use the macros (see below) Note that
+ * the macros evaluate their argument multiple times.
+ * PNG_NO_USE_READ_MACROS: call the relevant library function.
+ *
+ * Use the alternative algorithm for compositing alpha samples that
+ * does not use division?
+ * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
+ * algorithm.
+ * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
+ *
+ * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
+ * false?
+ * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
+ * APIs to png_warning.
+ * Otherwise the calls are mapped to png_error.
+ */
+
+/* Section 3: type definitions, including structures and compile time
+ * constants.
+ * See pngconf.h for base types that vary by machine/system
+ */
+
+/* This triggers a compiler error in png.c, if png.c and png.h
+ * do not agree upon the version number.
+ */
+typedef char* png_libpng_version_1_6_49_git;
+
+/* Basic control structions. Read libpng-manual.txt or libpng.3 for more info.
+ *
+ * png_struct is the cache of information used while reading or writing a single
+ * PNG file. One of these is always required, although the simplified API
+ * (below) hides the creation and destruction of it.
+ */
+typedef struct png_struct_def png_struct;
+typedef const png_struct * png_const_structp;
+typedef png_struct * png_structp;
+typedef png_struct * * png_structpp;
+
+/* png_info contains information read from or to be written to a PNG file. One
+ * or more of these must exist while reading or creating a PNG file. The
+ * information is not used by libpng during read but is used to control what
+ * gets written when a PNG file is created. "png_get_" function calls read
+ * information during read and "png_set_" functions calls write information
+ * when creating a PNG.
+ * been moved into a separate header file that is not accessible to
+ * applications. Read libpng-manual.txt or libpng.3 for more info.
+ */
+typedef struct png_info_def png_info;
+typedef png_info * png_infop;
+typedef const png_info * png_const_infop;
+typedef png_info * * png_infopp;
+
+/* Types with names ending 'p' are pointer types. The corresponding types with
+ * names ending 'rp' are identical pointer types except that the pointer is
+ * marked 'restrict', which means that it is the only pointer to the object
+ * passed to the function. Applications should not use the 'restrict' types;
+ * it is always valid to pass 'p' to a pointer with a function argument of the
+ * corresponding 'rp' type. Different compilers have different rules with
+ * regard to type matching in the presence of 'restrict'. For backward
+ * compatibility libpng callbacks never have 'restrict' in their parameters and,
+ * consequentially, writing portable application code is extremely difficult if
+ * an attempt is made to use 'restrict'.
+ */
+typedef png_struct * PNG_RESTRICT png_structrp;
+typedef const png_struct * PNG_RESTRICT png_const_structrp;
+typedef png_info * PNG_RESTRICT png_inforp;
+typedef const png_info * PNG_RESTRICT png_const_inforp;
+
+/* Three color definitions. The order of the red, green, and blue, (and the
+ * exact size) is not important, although the size of the fields need to
+ * be png_byte or png_uint_16 (as defined below).
+ */
+typedef struct png_color_struct
+{
+ png_byte red;
+ png_byte green;
+ png_byte blue;
+} png_color;
+typedef png_color * png_colorp;
+typedef const png_color * png_const_colorp;
+typedef png_color * * png_colorpp;
+
+typedef struct png_color_16_struct
+{
+ png_byte index; /* used for palette files */
+ png_uint_16 red; /* for use in red green blue files */
+ png_uint_16 green;
+ png_uint_16 blue;
+ png_uint_16 gray; /* for use in grayscale files */
+} png_color_16;
+typedef png_color_16 * png_color_16p;
+typedef const png_color_16 * png_const_color_16p;
+typedef png_color_16 * * png_color_16pp;
+
+typedef struct png_color_8_struct
+{
+ png_byte red; /* for use in red green blue files */
+ png_byte green;
+ png_byte blue;
+ png_byte gray; /* for use in grayscale files */
+ png_byte alpha; /* for alpha channel files */
+} png_color_8;
+typedef png_color_8 * png_color_8p;
+typedef const png_color_8 * png_const_color_8p;
+typedef png_color_8 * * png_color_8pp;
+
+/*
+ * The following two structures are used for the in-core representation
+ * of sPLT chunks.
+ */
+typedef struct png_sPLT_entry_struct
+{
+ png_uint_16 red;
+ png_uint_16 green;
+ png_uint_16 blue;
+ png_uint_16 alpha;
+ png_uint_16 frequency;
+} png_sPLT_entry;
+typedef png_sPLT_entry * png_sPLT_entryp;
+typedef const png_sPLT_entry * png_const_sPLT_entryp;
+typedef png_sPLT_entry * * png_sPLT_entrypp;
+
+/* When the depth of the sPLT palette is 8 bits, the color and alpha samples
+ * occupy the LSB of their respective members, and the MSB of each member
+ * is zero-filled. The frequency member always occupies the full 16 bits.
+ */
+
+typedef struct png_sPLT_struct
+{
+ png_charp name; /* palette name */
+ png_byte depth; /* depth of palette samples */
+ png_sPLT_entryp entries; /* palette entries */
+ png_int_32 nentries; /* number of palette entries */
+} png_sPLT_t;
+typedef png_sPLT_t * png_sPLT_tp;
+typedef const png_sPLT_t * png_const_sPLT_tp;
+typedef png_sPLT_t * * png_sPLT_tpp;
+
+#ifdef PNG_TEXT_SUPPORTED
+/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
+ * and whether that contents is compressed or not. The "key" field
+ * points to a regular zero-terminated C string. The "text" fields can be a
+ * regular C string, an empty string, or a NULL pointer.
+ * However, the structure returned by png_get_text() will always contain
+ * the "text" field as a regular zero-terminated C string (possibly
+ * empty), never a NULL pointer, so it can be safely used in printf() and
+ * other string-handling functions. Note that the "itxt_length", "lang", and
+ * "lang_key" members of the structure only exist when the library is built
+ * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by
+ * default without iTXt support. Also note that when iTXt *is* supported,
+ * the "lang" and "lang_key" fields contain NULL pointers when the
+ * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or
+ * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the
+ * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"
+ * which is always 0 or 1, or its "compression method" which is always 0.
+ */
+typedef struct png_text_struct
+{
+ int compression; /* compression value:
+ -1: tEXt, none
+ 0: zTXt, deflate
+ 1: iTXt, none
+ 2: iTXt, deflate */
+ png_charp key; /* keyword, 1-79 character description of "text" */
+ png_charp text; /* comment, may be an empty string (ie "")
+ or a NULL pointer */
+ size_t text_length; /* length of the text string */
+ size_t itxt_length; /* length of the itxt string */
+ png_charp lang; /* language code, 0-79 characters
+ or a NULL pointer */
+ png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
+ chars or a NULL pointer */
+} png_text;
+typedef png_text * png_textp;
+typedef const png_text * png_const_textp;
+typedef png_text * * png_textpp;
+#endif
+
+/* Supported compression types for text in PNG files (tEXt, and zTXt).
+ * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
+#define PNG_TEXT_COMPRESSION_NONE_WR -3
+#define PNG_TEXT_COMPRESSION_zTXt_WR -2
+#define PNG_TEXT_COMPRESSION_NONE -1
+#define PNG_TEXT_COMPRESSION_zTXt 0
+#define PNG_ITXT_COMPRESSION_NONE 1
+#define PNG_ITXT_COMPRESSION_zTXt 2
+#define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
+
+/* png_time is a way to hold the time in an machine independent way.
+ * Two conversions are provided, both from time_t and struct tm. There
+ * is no portable way to convert to either of these structures, as far
+ * as I know. If you know of a portable way, send it to me. As a side
+ * note - PNG has always been Year 2000 compliant!
+ */
+typedef struct png_time_struct
+{
+ png_uint_16 year; /* full year, as in, 1995 */
+ png_byte month; /* month of year, 1 - 12 */
+ png_byte day; /* day of month, 1 - 31 */
+ png_byte hour; /* hour of day, 0 - 23 */
+ png_byte minute; /* minute of hour, 0 - 59 */
+ png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
+} png_time;
+typedef png_time * png_timep;
+typedef const png_time * png_const_timep;
+typedef png_time * * png_timepp;
+
+#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\
+ defined(PNG_USER_CHUNKS_SUPPORTED)
+/* png_unknown_chunk is a structure to hold queued chunks for which there is
+ * no specific support. The idea is that we can use this to queue
+ * up private chunks for output even though the library doesn't actually
+ * know about their semantics.
+ *
+ * The data in the structure is set by libpng on read and used on write.
+ */
+typedef struct png_unknown_chunk_t
+{
+ png_byte name[5]; /* Textual chunk name with '\0' terminator */
+ png_byte *data; /* Data, should not be modified on read! */
+ size_t size;
+
+ /* On write 'location' must be set using the flag values listed below.
+ * Notice that on read it is set by libpng however the values stored have
+ * more bits set than are listed below. Always treat the value as a
+ * bitmask. On write set only one bit - setting multiple bits may cause the
+ * chunk to be written in multiple places.
+ */
+ png_byte location; /* mode of operation at read time */
+}
+png_unknown_chunk;
+
+typedef png_unknown_chunk * png_unknown_chunkp;
+typedef const png_unknown_chunk * png_const_unknown_chunkp;
+typedef png_unknown_chunk * * png_unknown_chunkpp;
+#endif
+
+/* Flag values for the unknown chunk location byte. */
+#define PNG_HAVE_IHDR 0x01
+#define PNG_HAVE_PLTE 0x02
+#define PNG_AFTER_IDAT 0x08
+
+/* Maximum positive integer used in PNG is (2^31)-1 */
+#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
+#define PNG_UINT_32_MAX ((png_uint_32)(-1))
+#define PNG_SIZE_MAX ((size_t)(-1))
+
+/* These are constants for fixed point values encoded in the
+ * PNG specification manner (x100000)
+ */
+#define PNG_FP_1 100000
+#define PNG_FP_HALF 50000
+#define PNG_FP_MAX ((png_fixed_point)0x7fffffffL)
+#define PNG_FP_MIN (-PNG_FP_MAX)
+
+/* These describe the color_type field in png_info. */
+/* color type masks */
+#define PNG_COLOR_MASK_PALETTE 1
+#define PNG_COLOR_MASK_COLOR 2
+#define PNG_COLOR_MASK_ALPHA 4
+
+/* color types. Note that not all combinations are legal */
+#define PNG_COLOR_TYPE_GRAY 0
+#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
+#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
+#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
+#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
+/* aliases */
+#define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
+#define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
+
+/* This is for compression type. PNG 1.0-1.2 only define the single type. */
+#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
+#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
+
+/* This is for filter type. PNG 1.0-1.2 only define the single type. */
+#define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
+#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
+#define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
+
+/* These are for the interlacing type. These values should NOT be changed. */
+#define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
+#define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
+#define PNG_INTERLACE_LAST 2 /* Not a valid value */
+
+/* These are for the oFFs chunk. These values should NOT be changed. */
+#define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
+#define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
+#define PNG_OFFSET_LAST 2 /* Not a valid value */
+
+/* These are for the pCAL chunk. These values should NOT be changed. */
+#define PNG_EQUATION_LINEAR 0 /* Linear transformation */
+#define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
+#define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
+#define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
+#define PNG_EQUATION_LAST 4 /* Not a valid value */
+
+/* These are for the sCAL chunk. These values should NOT be changed. */
+#define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
+#define PNG_SCALE_METER 1 /* meters per pixel */
+#define PNG_SCALE_RADIAN 2 /* radians per pixel */
+#define PNG_SCALE_LAST 3 /* Not a valid value */
+
+/* These are for the pHYs chunk. These values should NOT be changed. */
+#define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
+#define PNG_RESOLUTION_METER 1 /* pixels/meter */
+#define PNG_RESOLUTION_LAST 2 /* Not a valid value */
+
+/* These are for the sRGB chunk. These values should NOT be changed. */
+#define PNG_sRGB_INTENT_PERCEPTUAL 0
+#define PNG_sRGB_INTENT_RELATIVE 1
+#define PNG_sRGB_INTENT_SATURATION 2
+#define PNG_sRGB_INTENT_ABSOLUTE 3
+#define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
+
+/* This is for text chunks */
+#define PNG_KEYWORD_MAX_LENGTH 79
+
+/* Maximum number of entries in PLTE/sPLT/tRNS arrays */
+#define PNG_MAX_PALETTE_LENGTH 256
+
+/* These determine if an ancillary chunk's data has been successfully read
+ * from the PNG header, or if the application has filled in the corresponding
+ * data in the info_struct to be written into the output file. The values
+ * of the PNG_INFO_ defines should NOT be changed.
+ */
+#define PNG_INFO_gAMA 0x0001U
+#define PNG_INFO_sBIT 0x0002U
+#define PNG_INFO_cHRM 0x0004U
+#define PNG_INFO_PLTE 0x0008U
+#define PNG_INFO_tRNS 0x0010U
+#define PNG_INFO_bKGD 0x0020U
+#define PNG_INFO_hIST 0x0040U
+#define PNG_INFO_pHYs 0x0080U
+#define PNG_INFO_oFFs 0x0100U
+#define PNG_INFO_tIME 0x0200U
+#define PNG_INFO_pCAL 0x0400U
+#define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */
+#define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */
+#define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */
+#define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */
+#define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */
+#define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */
+#define PNG_INFO_cICP 0x20000U /* PNGv3: 1.6.45 */
+#define PNG_INFO_cLLI 0x40000U /* PNGv3: 1.6.45 */
+#define PNG_INFO_mDCV 0x80000U /* PNGv3: 1.6.45 */
+/* APNG: these chunks are stored as unknown, these flags are never set
+ * however they are provided as a convenience for implementors of APNG and
+ * avoids any merge conflicts.
+ *
+ * Private chunks: these chunk names violate the chunk name recommendations
+ * because the chunk definitions have no signature and because the private
+ * chunks with these names have been reserved. Private definitions should
+ * avoid them.
+ */
+#define PNG_INFO_acTL 0x100000U /* PNGv3: 1.6.45: unknown */
+#define PNG_INFO_fcTL 0x200000U /* PNGv3: 1.6.45: unknown */
+#define PNG_INFO_fdAT 0x400000U /* PNGv3: 1.6.45: unknown */
+
+/* This is used for the transformation routines, as some of them
+ * change these values for the row. It also should enable using
+ * the routines for other purposes.
+ */
+typedef struct png_row_info_struct
+{
+ png_uint_32 width; /* width of row */
+ size_t rowbytes; /* number of bytes in row */
+ png_byte color_type; /* color type of row */
+ png_byte bit_depth; /* bit depth of row */
+ png_byte channels; /* number of channels (1, 2, 3, or 4) */
+ png_byte pixel_depth; /* bits per pixel (depth * channels) */
+} png_row_info;
+
+typedef png_row_info * png_row_infop;
+typedef png_row_info * * png_row_infopp;
+
+/* These are the function types for the I/O functions and for the functions
+ * that allow the user to override the default I/O functions with his or her
+ * own. The png_error_ptr type should match that of user-supplied warning
+ * and error functions, while the png_rw_ptr type should match that of the
+ * user read/write data functions. Note that the 'write' function must not
+ * modify the buffer it is passed. The 'read' function, on the other hand, is
+ * expected to return the read data in the buffer.
+ */
+typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));
+typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, size_t));
+typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));
+typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,
+ int));
+typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
+ int));
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
+typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
+
+/* The following callback receives png_uint_32 row_number, int pass for the
+ * png_bytep data of the row. When transforming an interlaced image the
+ * row number is the row number within the sub-image of the interlace pass, so
+ * the value will increase to the height of the sub-image (not the full image)
+ * then reset to 0 for the next pass.
+ *
+ * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
+ * find the output pixel (x,y) given an interlaced sub-image pixel
+ * (row,col,pass). (See below for these macros.)
+ */
+typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep,
+ png_uint_32, int));
+#endif
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop,
+ png_bytep));
+#endif
+
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,
+ png_unknown_chunkp));
+#endif
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+/* not used anywhere */
+/* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+/* This must match the function definition in , and the application
+ * must include this before png.h to obtain the definition of jmp_buf. The
+ * function is required to be PNG_NORETURN, but this is not checked. If the
+ * function does return the application will crash via an abort() or similar
+ * system level call.
+ *
+ * If you get a warning here while building the library you may need to make
+ * changes to ensure that pnglibconf.h records the calling convention used by
+ * your compiler. This may be very difficult - try using a different compiler
+ * to build the library!
+ */
+PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), (jmp_buf, int), typedef);
+#endif
+
+/* Transform masks for the high-level interface */
+#define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
+#define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
+#define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
+#define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
+#define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
+#define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
+#define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
+#define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
+#define PNG_TRANSFORM_BGR 0x0080 /* read and write */
+#define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
+#define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
+#define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
+#define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
+/* Added to libpng-1.2.34 */
+#define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
+#define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
+/* Added to libpng-1.4.0 */
+#define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
+/* Added to libpng-1.5.4 */
+#define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */
+#if ~0U > 0xffffU /* or else this might break on a 16-bit machine */
+#define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */
+#endif
+
+/* Flags for MNG supported features */
+#define PNG_FLAG_MNG_EMPTY_PLTE 0x01
+#define PNG_FLAG_MNG_FILTER_64 0x04
+#define PNG_ALL_MNG_FEATURES 0x05
+
+/* NOTE: prior to 1.5 these functions had no 'API' style declaration,
+ * this allowed the zlib default functions to be used on Windows
+ * platforms. In 1.5 the zlib default malloc (which just calls malloc and
+ * ignores the first argument) should be completely compatible with the
+ * following.
+ */
+typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp,
+ png_alloc_size_t));
+typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp));
+
+/* Section 4: exported functions
+ * Here are the function definitions most commonly used. This is not
+ * the place to find out how to use libpng. See libpng-manual.txt for the
+ * full explanation, see example.c for the summary. This just provides
+ * a simple one line description of the use of each function.
+ *
+ * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
+ * pngconf.h and in the *.dfn files in the scripts directory.
+ *
+ * PNG_EXPORT(ordinal, type, name, (args));
+ *
+ * ordinal: ordinal that is used while building
+ * *.def files. The ordinal value is only
+ * relevant when preprocessing png.h with
+ * the *.dfn files for building symbol table
+ * entries, and are removed by pngconf.h.
+ * type: return type of the function
+ * name: function name
+ * args: function arguments, with types
+ *
+ * When we wish to append attributes to a function prototype we use
+ * the PNG_EXPORTA() macro instead.
+ *
+ * PNG_EXPORTA(ordinal, type, name, (args), attributes);
+ *
+ * ordinal, type, name, and args: same as in PNG_EXPORT().
+ * attributes: function attributes
+ */
+
+/* Returns the version number of the library */
+PNG_EXPORT(1, png_uint_32, png_access_version_number, (void));
+
+/* Tell lib we have already handled the first magic bytes.
+ * Handling more than 8 bytes from the beginning of the file is an error.
+ */
+PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes));
+
+/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
+ * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
+ * signature, and non-zero otherwise. Having num_to_check == 0 or
+ * start > 7 will always fail (i.e. return non-zero).
+ */
+PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, size_t start,
+ size_t num_to_check));
+
+/* Simple signature checking function. This is the same as calling
+ * png_check_sig(sig, n) := (png_sig_cmp(sig, 0, n) == 0).
+ */
+#define png_check_sig(sig, n) (png_sig_cmp((sig), 0, (n)) == 0) /* DEPRECATED */
+
+/* Allocate and initialize png_ptr struct for reading, and any other memory. */
+PNG_EXPORTA(4, png_structp, png_create_read_struct,
+ (png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn),
+ PNG_ALLOCATED);
+
+/* Allocate and initialize png_ptr struct for writing, and any other memory */
+PNG_EXPORTA(5, png_structp, png_create_write_struct,
+ (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
+ png_error_ptr warn_fn),
+ PNG_ALLOCATED);
+
+PNG_EXPORT(6, size_t, png_get_compression_buffer_size,
+ (png_const_structrp png_ptr));
+
+PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr,
+ size_t size));
+
+/* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
+ * match up.
+ */
+#ifdef PNG_SETJMP_SUPPORTED
+/* This function returns the jmp_buf built in to *png_ptr. It must be
+ * supplied with an appropriate 'longjmp' function to use on that jmp_buf
+ * unless the default error function is overridden in which case NULL is
+ * acceptable. The size of the jmp_buf is checked against the actual size
+ * allocated by the library - the call will return NULL on a mismatch
+ * indicating an ABI mismatch.
+ */
+PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr,
+ png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
+# define png_jmpbuf(png_ptr) \
+ (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf))))
+#else
+# define png_jmpbuf(png_ptr) \
+ (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
+#endif
+/* This function should be used by libpng applications in place of
+ * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it
+ * will use it; otherwise it will call PNG_ABORT(). This function was
+ * added in libpng-1.5.0.
+ */
+PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val),
+ PNG_NORETURN);
+
+#ifdef PNG_READ_SUPPORTED
+/* Reset the compression stream */
+PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED);
+#endif
+
+/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
+#ifdef PNG_USER_MEM_SUPPORTED
+PNG_EXPORTA(11, png_structp, png_create_read_struct_2,
+ (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
+ png_error_ptr warn_fn,
+ png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
+ PNG_ALLOCATED);
+PNG_EXPORTA(12, png_structp, png_create_write_struct_2,
+ (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
+ png_error_ptr warn_fn,
+ png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
+ PNG_ALLOCATED);
+#endif
+
+/* Write the PNG file signature. */
+PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr));
+
+/* Write a PNG chunk - size, type, (optional) data, CRC. */
+PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep
+ chunk_name, png_const_bytep data, size_t length));
+
+/* Write the start of a PNG chunk - length and chunk name. */
+PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr,
+ png_const_bytep chunk_name, png_uint_32 length));
+
+/* Write the data of a PNG chunk started with png_write_chunk_start(). */
+PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr,
+ png_const_bytep data, size_t length));
+
+/* Finish a chunk started with png_write_chunk_start() (includes CRC). */
+PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr));
+
+/* Allocate and initialize the info structure */
+PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr),
+ PNG_ALLOCATED);
+
+/* DEPRECATED: this function allowed init structures to be created using the
+ * default allocation method (typically malloc). Use is deprecated in 1.6.0 and
+ * the API will be removed in the future.
+ */
+PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr,
+ size_t png_info_struct_size), PNG_DEPRECATED);
+
+/* Writes all the PNG information before the image. */
+PNG_EXPORT(20, void, png_write_info_before_PLTE,
+ (png_structrp png_ptr, png_const_inforp info_ptr));
+PNG_EXPORT(21, void, png_write_info,
+ (png_structrp png_ptr, png_const_inforp info_ptr));
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the information before the actual image data. */
+PNG_EXPORT(22, void, png_read_info,
+ (png_structrp png_ptr, png_inforp info_ptr));
+#endif
+
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+ /* Convert to a US string format: there is no localization support in this
+ * routine. The original implementation used a 29 character buffer in
+ * png_struct, this will be removed in future versions.
+ */
+#if PNG_LIBPNG_VER < 10700
+/* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */
+PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr,
+ png_const_timep ptime),PNG_DEPRECATED);
+#endif
+PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29],
+ png_const_timep ptime));
+#endif
+
+#ifdef PNG_CONVERT_tIME_SUPPORTED
+/* Convert from a struct tm to png_time */
+PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
+ const struct tm * ttime));
+
+/* Convert from time_t to png_time. Uses gmtime() */
+PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime));
+#endif /* CONVERT_tIME */
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
+PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr));
+PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr));
+PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr));
+PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr));
+#endif
+
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+/* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
+ * of a tRNS chunk if present.
+ */
+PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr));
+#endif
+
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+/* Use blue, green, red order for pixels. */
+PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr));
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+/* Expand the grayscale to 24-bit RGB if necessary. */
+PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr));
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+/* Reduce RGB to grayscale. */
+#define PNG_ERROR_ACTION_NONE 1
+#define PNG_ERROR_ACTION_WARN 2
+#define PNG_ERROR_ACTION_ERROR 3
+#define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/
+
+PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr,
+ int error_action, double red, double green))
+PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr,
+ int error_action, png_fixed_point red, png_fixed_point green))
+
+PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp
+ png_ptr));
+#endif
+
+#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
+PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
+ png_colorp palette));
+#endif
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+/* How the alpha channel is interpreted - this affects how the color channels
+ * of a PNG file are returned to the calling application when an alpha channel,
+ * or a tRNS chunk in a palette file, is present.
+ *
+ * This has no effect on the way pixels are written into a PNG output
+ * datastream. The color samples in a PNG datastream are never premultiplied
+ * with the alpha samples.
+ *
+ * The default is to return data according to the PNG specification: the alpha
+ * channel is a linear measure of the contribution of the pixel to the
+ * corresponding composited pixel, and the color channels are unassociated
+ * (not premultiplied). The gamma encoded color channels must be scaled
+ * according to the contribution and to do this it is necessary to undo
+ * the encoding, scale the color values, perform the composition and re-encode
+ * the values. This is the 'PNG' mode.
+ *
+ * The alternative is to 'associate' the alpha with the color information by
+ * storing color channel values that have been scaled by the alpha.
+ * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
+ * (the latter being the two common names for associated alpha color channels).
+ *
+ * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha
+ * value is equal to the maximum value.
+ *
+ * The final choice is to gamma encode the alpha channel as well. This is
+ * broken because, in practice, no implementation that uses this choice
+ * correctly undoes the encoding before handling alpha composition. Use this
+ * choice only if other serious errors in the software or hardware you use
+ * mandate it; the typical serious error is for dark halos to appear around
+ * opaque areas of the composited PNG image because of arithmetic overflow.
+ *
+ * The API function png_set_alpha_mode specifies which of these choices to use
+ * with an enumerated 'mode' value and the gamma of the required output:
+ */
+#define PNG_ALPHA_PNG 0 /* according to the PNG standard */
+#define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */
+#define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */
+#define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
+#define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */
+#define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */
+
+PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode,
+ double output_gamma))
+PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr,
+ int mode, png_fixed_point output_gamma))
+#endif
+
+#if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+/* The output_gamma value is a screen gamma in libpng terminology: it expresses
+ * how to decode the output values, not how they are encoded.
+ */
+#define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */
+#define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */
+#define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */
+#define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
+#endif
+
+/* The following are examples of calls to png_set_alpha_mode to achieve the
+ * required overall gamma correction and, where necessary, alpha
+ * premultiplication.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
+ * This is the default libpng handling of the alpha channel - it is not
+ * pre-multiplied into the color components. In addition the call states
+ * that the output is for a sRGB system and causes all PNG files without gAMA
+ * chunks to be assumed to be encoded using sRGB.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
+ * In this case the output is assumed to be something like an sRGB conformant
+ * display preceded by a power-law lookup table of power 1.45. This is how
+ * early Mac systems behaved.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
+ * This is the classic Jim Blinn approach and will work in academic
+ * environments where everything is done by the book. It has the shortcoming
+ * of assuming that input PNG data with no gamma information is linear - this
+ * is unlikely to be correct unless the PNG files where generated locally.
+ * Most of the time the output precision will be so low as to show
+ * significant banding in dark areas of the image.
+ *
+ * png_set_expand_16(pp);
+ * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
+ * This is a somewhat more realistic Jim Blinn inspired approach. PNG files
+ * are assumed to have the sRGB encoding if not marked with a gamma value and
+ * the output is always 16 bits per component. This permits accurate scaling
+ * and processing of the data. If you know that your input PNG files were
+ * generated locally you might need to replace PNG_DEFAULT_sRGB with the
+ * correct value for your system.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
+ * If you just need to composite the PNG image onto an existing background
+ * and if you control the code that does this you can use the optimization
+ * setting. In this case you just copy completely opaque pixels to the
+ * output. For pixels that are not completely transparent (you just skip
+ * those) you do the composition math using png_composite or png_composite_16
+ * below then encode the resultant 8-bit or 16-bit values to match the output
+ * encoding.
+ *
+ * Other cases
+ * If neither the PNG nor the standard linear encoding work for you because
+ * of the software or hardware you use then you have a big problem. The PNG
+ * case will probably result in halos around the image. The linear encoding
+ * will probably result in a washed out, too bright, image (it's actually too
+ * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably
+ * substantially reduce the halos. Alternatively try:
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
+ * This option will also reduce the halos, but there will be slight dark
+ * halos round the opaque parts of the image where the background is light.
+ * In the OPTIMIZED mode the halos will be light halos where the background
+ * is dark. Take your pick - the halos are unavoidable unless you can get
+ * your hardware/software fixed! (The OPTIMIZED approach is slightly
+ * faster.)
+ *
+ * When the default gamma of PNG files doesn't match the output gamma.
+ * If you have PNG files with no gamma information png_set_alpha_mode allows
+ * you to provide a default gamma, but it also sets the output gamma to the
+ * matching value. If you know your PNG files have a gamma that doesn't
+ * match the output you can take advantage of the fact that
+ * png_set_alpha_mode always sets the output gamma but only sets the PNG
+ * default if it is not already set:
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
+ * The first call sets both the default and the output gamma values, the
+ * second call overrides the output gamma without changing the default. This
+ * is easier than achieving the same effect with png_set_gamma. You must use
+ * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
+ * fire if more than one call to png_set_alpha_mode and png_set_background is
+ * made in the same read operation, however multiple calls with PNG_ALPHA_PNG
+ * are ignored.
+ */
+
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr));
+#endif
+
+#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
+ defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
+PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr));
+#endif
+
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
+ defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
+PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr));
+#endif
+
+#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
+/* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
+PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler,
+ int flags));
+/* The values of the PNG_FILLER_ defines should NOT be changed */
+# define PNG_FILLER_BEFORE 0
+# define PNG_FILLER_AFTER 1
+/* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
+PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr,
+ png_uint_32 filler, int flags));
+#endif /* READ_FILLER || WRITE_FILLER */
+
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+/* Swap bytes in 16-bit depth files. */
+PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr));
+#endif
+
+#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
+PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr));
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
+ defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+/* Swap packing order of pixels in bytes. */
+PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr));
+#endif
+
+#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
+/* Converts files to legal bit depths. */
+PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p
+ true_bits));
+#endif
+
+#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
+ defined(PNG_WRITE_INTERLACING_SUPPORTED)
+/* Have the code handle the interlacing. Returns the number of passes.
+ * MUST be called before png_read_update_info or png_start_read_image,
+ * otherwise it will not have the desired effect. Note that it is still
+ * necessary to call png_read_row or png_read_rows png_get_image_height
+ * times for each pass.
+*/
+PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr));
+#endif
+
+#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
+/* Invert monochrome files */
+PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr));
+#endif
+
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+/* Handle alpha and tRNS by replacing with a background color. Prior to
+ * libpng-1.5.4 this API must not be called before the PNG file header has been
+ * read. Doing so will result in unexpected behavior and possible warnings or
+ * errors if the PNG file contains a bKGD chunk.
+ */
+PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr,
+ png_const_color_16p background_color, int background_gamma_code,
+ int need_expand, double background_gamma))
+PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr,
+ png_const_color_16p background_color, int background_gamma_code,
+ int need_expand, png_fixed_point background_gamma))
+#endif
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+# define PNG_BACKGROUND_GAMMA_UNKNOWN 0
+# define PNG_BACKGROUND_GAMMA_SCREEN 1
+# define PNG_BACKGROUND_GAMMA_FILE 2
+# define PNG_BACKGROUND_GAMMA_UNIQUE 3
+#endif
+
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+/* Scale a 16-bit depth file down to 8-bit, accurately. */
+PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr));
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+#define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */
+/* Strip the second byte of information from a 16-bit depth file. */
+PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr));
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+/* Turn on quantizing, and reduce the palette to the number of colors
+ * available.
+ */
+PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr,
+ png_colorp palette, int num_palette, int maximum_colors,
+ png_const_uint_16p histogram, int full_quantize));
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* The threshold on gamma processing is configurable but hard-wired into the
+ * library. The following is the floating point variant.
+ */
+#define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
+
+/* Handle gamma correction. Screen_gamma=(display_exponent).
+ * NOTE: this API simply sets the screen and file gamma values. It will
+ * therefore override the value for gamma in a PNG file if it is called after
+ * the file header has been read - use with care - call before reading the PNG
+ * file for best results!
+ *
+ * These routines accept the same gamma values as png_set_alpha_mode (described
+ * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
+ * API (floating point or fixed.) Notice, however, that the 'file_gamma' value
+ * is the inverse of a 'screen gamma' value.
+ */
+PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr,
+ double screen_gamma, double override_file_gamma))
+PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr,
+ png_fixed_point screen_gamma, png_fixed_point override_file_gamma))
+#endif
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+/* Set how many lines between output flushes - 0 for no flushing */
+PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows));
+/* Flush the current PNG output buffer */
+PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr));
+#endif
+
+/* Optional update palette with requested transformations */
+PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr));
+
+/* Optional call to update the users info structure */
+PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr,
+ png_inforp info_ptr));
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read one or more rows of image data. */
+PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row,
+ png_bytepp display_row, png_uint_32 num_rows));
+#endif
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read a row of data. */
+PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row,
+ png_bytep display_row));
+#endif
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the whole image into memory at once. */
+PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image));
+#endif
+
+/* Write a row of image data */
+PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr,
+ png_const_bytep row));
+
+/* Write a few rows of image data: (*row) is not written; however, the type
+ * is declared as writeable to maintain compatibility with previous versions
+ * of libpng and to allow the 'display_row' array from read_rows to be passed
+ * unchanged to write_rows.
+ */
+PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row,
+ png_uint_32 num_rows));
+
+/* Write the image data */
+PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image));
+
+/* Write the end of the PNG file. */
+PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr,
+ png_inforp info_ptr));
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the end of the PNG file. */
+PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr));
+#endif
+
+/* Free any memory associated with the png_info_struct */
+PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr,
+ png_infopp info_ptr_ptr));
+
+/* Free any memory associated with the png_struct and the png_info_structs */
+PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr,
+ png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
+
+/* Free any memory associated with the png_struct and the png_info_structs */
+PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr,
+ png_infopp info_ptr_ptr));
+
+/* Set the libpng method of handling chunk CRC errors */
+PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action,
+ int ancil_action));
+
+/* Values for png_set_crc_action() say how to handle CRC errors in
+ * ancillary and critical chunks, and whether to use the data contained
+ * therein. Note that it is impossible to "discard" data in a critical
+ * chunk. For versions prior to 0.90, the action was always error/quit,
+ * whereas in version 0.90 and later, the action for CRC errors in ancillary
+ * chunks is warn/discard. These values should NOT be changed.
+ *
+ * value action:critical action:ancillary
+ */
+#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
+#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
+#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
+#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
+#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
+#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
+
+#ifdef PNG_WRITE_SUPPORTED
+/* These functions give the user control over the scan-line filtering in
+ * libpng and the compression methods used by zlib. These functions are
+ * mainly useful for testing, as the defaults should work with most users.
+ * Those users who are tight on memory or want faster performance at the
+ * expense of compression can modify them. See the compression library
+ * header file (zlib.h) for an explanation of the compression functions.
+ */
+
+/* Set the filtering method(s) used by libpng. Currently, the only valid
+ * value for "method" is 0.
+ */
+PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
+ int filters));
+#endif /* WRITE */
+
+/* Flags for png_set_filter() to say which filters to use. The flags
+ * are chosen so that they don't conflict with real filter types
+ * below, in case they are supplied instead of the #defined constants.
+ * These values should NOT be changed.
+ */
+#define PNG_NO_FILTERS 0x00
+#define PNG_FILTER_NONE 0x08
+#define PNG_FILTER_SUB 0x10
+#define PNG_FILTER_UP 0x20
+#define PNG_FILTER_AVG 0x40
+#define PNG_FILTER_PAETH 0x80
+#define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP)
+#define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH)
+
+/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
+ * These defines should NOT be changed.
+ */
+#define PNG_FILTER_VALUE_NONE 0
+#define PNG_FILTER_VALUE_SUB 1
+#define PNG_FILTER_VALUE_UP 2
+#define PNG_FILTER_VALUE_AVG 3
+#define PNG_FILTER_VALUE_PAETH 4
+#define PNG_FILTER_VALUE_LAST 5
+
+#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
+PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr,
+ int heuristic_method, int num_weights, png_const_doublep filter_weights,
+ png_const_doublep filter_costs))
+PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
+ (png_structrp png_ptr, int heuristic_method, int num_weights,
+ png_const_fixed_point_p filter_weights,
+ png_const_fixed_point_p filter_costs))
+#endif /* WRITE_WEIGHTED_FILTER */
+
+/* The following are no longer used and will be removed from libpng-1.7: */
+#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
+#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
+#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
+#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
+
+/* Set the library compression level. Currently, valid values range from
+ * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
+ * (0 - no compression, 9 - "maximal" compression). Note that tests have
+ * shown that zlib compression levels 3-6 usually perform as well as level 9
+ * for PNG images, and do considerably fewer calculations. In the future,
+ * these values may not correspond directly to the zlib compression levels.
+ */
+#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
+PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr,
+ int level));
+
+PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr,
+ int mem_level));
+
+PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr,
+ int strategy));
+
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
+PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr,
+ int window_bits));
+
+PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr,
+ int method));
+#endif /* WRITE_CUSTOMIZE_COMPRESSION */
+
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+/* Also set zlib parameters for compressing non-IDAT chunks */
+PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr,
+ int level));
+
+PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr,
+ int mem_level));
+
+PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr,
+ int strategy));
+
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
+PNG_EXPORT(225, void, png_set_text_compression_window_bits,
+ (png_structrp png_ptr, int window_bits));
+
+PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,
+ int method));
+#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
+#endif /* WRITE */
+
+/* These next functions are called for input/output, memory, and error
+ * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
+ * and call standard C I/O routines such as fread(), fwrite(), and
+ * fprintf(). These functions can be made to use other I/O routines
+ * at run time for those applications that need to handle I/O in a
+ * different manner by calling png_set_???_fn(). See libpng-manual.txt for
+ * more information.
+ */
+
+#ifdef PNG_STDIO_SUPPORTED
+/* Initialize the input/output for the PNG file to the default functions. */
+PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, FILE *fp));
+#endif
+
+/* Replace the (error and abort), and warning functions with user
+ * supplied functions. If no messages are to be printed you must still
+ * write and use replacement functions. The replacement error_fn should
+ * still do a longjmp to the last setjmp location if you are using this
+ * method of error handling. If error_fn or warning_fn is NULL, the
+ * default function will be used.
+ */
+
+PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr,
+ png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
+
+/* Return the user pointer associated with the error functions */
+PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr));
+
+/* Replace the default data output functions with a user supplied one(s).
+ * If buffered output is not used, then output_flush_fn can be set to NULL.
+ * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
+ * output_flush_fn will be ignored (and thus can be NULL).
+ * It is probably a mistake to use NULL for output_flush_fn if
+ * write_data_fn is not also NULL unless you have built libpng with
+ * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
+ * default flush function, which uses the standard *FILE structure, will
+ * be used.
+ */
+PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr,
+ png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
+
+/* Replace the default data input function with a user supplied one. */
+PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr,
+ png_rw_ptr read_data_fn));
+
+/* Return the user pointer associated with the I/O functions */
+PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr));
+
+PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr,
+ png_read_status_ptr read_row_fn));
+
+PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr,
+ png_write_status_ptr write_row_fn));
+
+#ifdef PNG_USER_MEM_SUPPORTED
+/* Replace the default memory allocation functions with user supplied one(s). */
+PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr,
+ png_malloc_ptr malloc_fn, png_free_ptr free_fn));
+/* Return the user pointer associated with the memory functions */
+PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr));
+#endif
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr,
+ png_user_transform_ptr read_user_transform_fn));
+#endif
+
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr,
+ png_user_transform_ptr write_user_transform_fn));
+#endif
+
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr,
+ png_voidp user_transform_ptr, int user_transform_depth,
+ int user_transform_channels));
+/* Return the user pointer associated with the user transform functions */
+PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,
+ (png_const_structrp png_ptr));
+#endif
+
+#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
+/* Return information about the row currently being processed. Note that these
+ * APIs do not fail but will return unexpected results if called outside a user
+ * transform callback. Also note that when transforming an interlaced image the
+ * row number is the row number within the sub-image of the interlace pass, so
+ * the value will increase to the height of the sub-image (not the full image)
+ * then reset to 0 for the next pass.
+ *
+ * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
+ * find the output pixel (x,y) given an interlaced sub-image pixel
+ * (row,col,pass). (See below for these macros.)
+ */
+PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp));
+PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp));
+#endif
+
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+/* This callback is called only for *unknown* chunks. If
+ * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known
+ * chunks to be treated as unknown, however in this case the callback must do
+ * any processing required by the chunk (e.g. by calling the appropriate
+ * png_set_ APIs.)
+ *
+ * There is no write support - on write, by default, all the chunks in the
+ * 'unknown' list are written in the specified position.
+ *
+ * The integer return from the callback function is interpreted thus:
+ *
+ * negative: An error occurred; png_chunk_error will be called.
+ * zero: The chunk was not handled, the chunk will be saved. A critical
+ * chunk will cause an error at this point unless it is to be saved.
+ * positive: The chunk was handled, libpng will ignore/discard it.
+ *
+ * See "INTERACTION WITH USER CHUNK CALLBACKS" below for important notes about
+ * how this behavior will change in libpng 1.7
+ */
+PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr,
+ png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
+#endif
+
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr));
+#endif
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+/* Sets the function callbacks for the push reader, and a pointer to a
+ * user-defined structure available to the callback functions.
+ */
+PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr,
+ png_voidp progressive_ptr, png_progressive_info_ptr info_fn,
+ png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
+
+/* Returns the user pointer associated with the push read functions */
+PNG_EXPORT(91, png_voidp, png_get_progressive_ptr,
+ (png_const_structrp png_ptr));
+
+/* Function to be called when data becomes available */
+PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr,
+ png_inforp info_ptr, png_bytep buffer, size_t buffer_size));
+
+/* A function which may be called *only* within png_process_data to stop the
+ * processing of any more data. The function returns the number of bytes
+ * remaining, excluding any that libpng has cached internally. A subsequent
+ * call to png_process_data must supply these bytes again. If the argument
+ * 'save' is set to true the routine will first save all the pending data and
+ * will always return 0.
+ */
+PNG_EXPORT(219, size_t, png_process_data_pause, (png_structrp, int save));
+
+/* A function which may be called *only* outside (after) a call to
+ * png_process_data. It returns the number of bytes of data to skip in the
+ * input. Normally it will return 0, but if it returns a non-zero value the
+ * application must skip than number of bytes of input data and pass the
+ * following data to the next call to png_process_data.
+ */
+PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp));
+
+/* Function that combines rows. 'new_row' is a flag that should come from
+ * the callback and be non-NULL if anything needs to be done; the library
+ * stores its own version of the new data internally and ignores the passed
+ * in value.
+ */
+PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr,
+ png_bytep old_row, png_const_bytep new_row));
+#endif /* PROGRESSIVE_READ */
+
+PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr,
+ png_alloc_size_t size), PNG_ALLOCATED);
+/* Added at libpng version 1.4.0 */
+PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr,
+ png_alloc_size_t size), PNG_ALLOCATED);
+
+/* Added at libpng version 1.2.4 */
+PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr,
+ png_alloc_size_t size), PNG_ALLOCATED);
+
+/* Frees a pointer allocated by png_malloc() */
+PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr));
+
+/* Free data that was allocated internally */
+PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 free_me, int num));
+
+/* Reassign the responsibility for freeing existing data, whether allocated
+ * by libpng or by the application; this works on the png_info structure passed
+ * in, without changing the state for other png_info structures.
+ */
+PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr,
+ png_inforp info_ptr, int freer, png_uint_32 mask));
+
+/* Assignments for png_data_freer */
+#define PNG_DESTROY_WILL_FREE_DATA 1
+#define PNG_SET_WILL_FREE_DATA 1
+#define PNG_USER_WILL_FREE_DATA 2
+/* Flags for png_ptr->free_me and info_ptr->free_me */
+#define PNG_FREE_HIST 0x0008U
+#define PNG_FREE_ICCP 0x0010U
+#define PNG_FREE_SPLT 0x0020U
+#define PNG_FREE_ROWS 0x0040U
+#define PNG_FREE_PCAL 0x0080U
+#define PNG_FREE_SCAL 0x0100U
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+# define PNG_FREE_UNKN 0x0200U
+#endif
+/* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */
+#define PNG_FREE_PLTE 0x1000U
+#define PNG_FREE_TRNS 0x2000U
+#define PNG_FREE_TEXT 0x4000U
+#define PNG_FREE_EXIF 0x8000U /* Added at libpng-1.6.31 */
+#define PNG_FREE_ALL 0xffffU
+#define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
+
+#ifdef PNG_USER_MEM_SUPPORTED
+PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr,
+ png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED);
+PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr,
+ png_voidp ptr), PNG_DEPRECATED);
+#endif
+
+#ifdef PNG_ERROR_TEXT_SUPPORTED
+/* Fatal error in PNG image of libpng - can't continue */
+PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr,
+ png_const_charp error_message), PNG_NORETURN);
+
+/* The same, but the chunk name is prepended to the error string. */
+PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr,
+ png_const_charp error_message), PNG_NORETURN);
+
+#else
+/* Fatal error in PNG image of libpng - can't continue */
+PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN);
+# define png_error(s1,s2) png_err(s1)
+# define png_chunk_error(s1,s2) png_err(s1)
+#endif
+
+#ifdef PNG_WARNINGS_SUPPORTED
+/* Non-fatal error in libpng. Can continue, but may have a problem. */
+PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr,
+ png_const_charp warning_message));
+
+/* Non-fatal error in libpng, chunk name is prepended to message. */
+PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr,
+ png_const_charp warning_message));
+#else
+# define png_warning(s1,s2) ((void)(s1))
+# define png_chunk_warning(s1,s2) ((void)(s1))
+#endif
+
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+/* Benign error in libpng. Can continue, but may have a problem.
+ * User can choose whether to handle as a fatal error or as a warning. */
+PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr,
+ png_const_charp warning_message));
+
+#ifdef PNG_READ_SUPPORTED
+/* Same, chunk name is prepended to message (only during read) */
+PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr,
+ png_const_charp warning_message));
+#endif
+
+PNG_EXPORT(109, void, png_set_benign_errors,
+ (png_structrp png_ptr, int allowed));
+#else
+# ifdef PNG_ALLOW_BENIGN_ERRORS
+# define png_benign_error png_warning
+# define png_chunk_benign_error png_chunk_warning
+# else
+# define png_benign_error png_error
+# define png_chunk_benign_error png_chunk_error
+# endif
+#endif
+
+/* The png_set_ functions are for storing values in the png_info_struct.
+ * Similarly, the png_get_ calls are used to read values from the
+ * png_info_struct, either storing the parameters in the passed variables, or
+ * setting pointers into the png_info_struct where the data is stored. The
+ * png_get_ functions return a non-zero value if the data was available
+ * in info_ptr, or return zero and do not change any of the parameters if the
+ * data was not available.
+ *
+ * These functions should be used instead of directly accessing png_info
+ * to avoid problems with future changes in the size and internal layout of
+ * png_info_struct.
+ */
+/* Returns "flag" if chunk data is valid in info_ptr. */
+PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr, png_uint_32 flag));
+
+/* Returns number of bytes needed to hold a transformed row. */
+PNG_EXPORT(111, size_t, png_get_rowbytes, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr));
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+/* Returns row_pointers, which is an array of pointers to scanlines that was
+ * returned from png_read_png().
+ */
+PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr));
+
+/* Set row_pointers, which is an array of pointers to scanlines for use
+ * by png_write_png().
+ */
+PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_bytepp row_pointers));
+#endif
+
+/* Returns number of color channels in image. */
+PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr));
+
+#ifdef PNG_EASY_ACCESS_SUPPORTED
+/* Returns image width in pixels. */
+PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr));
+
+/* Returns image height in pixels. */
+PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr));
+
+/* Returns image bit_depth. */
+PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr));
+
+/* Returns image color_type. */
+PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr));
+
+/* Returns image filter_type. */
+PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr));
+
+/* Returns image interlace_type. */
+PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr));
+
+/* Returns image compression_type. */
+PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr));
+
+/* Returns image resolution in pixels per meter, from pHYs chunk data. */
+PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr));
+PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr));
+PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr));
+
+/* Returns pixel aspect ratio, computed from pHYs chunk data. */
+PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr))
+PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr))
+
+/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
+PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr));
+PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr));
+PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr));
+PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr));
+
+#endif /* EASY_ACCESS */
+
+#ifdef PNG_READ_SUPPORTED
+/* Returns pointer to signature string read from PNG header */
+PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr));
+#endif
+
+#ifdef PNG_bKGD_SUPPORTED
+PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_color_16p *background));
+#endif
+
+#ifdef PNG_bKGD_SUPPORTED
+PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_const_color_16p background));
+#endif
+
+#ifdef PNG_cHRM_SUPPORTED
+PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x,
+ double *red_y, double *green_x, double *green_y, double *blue_x,
+ double *blue_y))
+PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z,
+ double *green_X, double *green_Y, double *green_Z, double *blue_X,
+ double *blue_Y, double *blue_Z))
+PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_fixed_point *int_white_x, png_fixed_point *int_white_y,
+ png_fixed_point *int_red_x, png_fixed_point *int_red_y,
+ png_fixed_point *int_green_x, png_fixed_point *int_green_y,
+ png_fixed_point *int_blue_x, png_fixed_point *int_blue_y))
+PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
+ png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
+ png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
+ png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
+ png_fixed_point *int_blue_Z))
+#endif
+
+#ifdef PNG_cHRM_SUPPORTED
+PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr,
+ png_inforp info_ptr,
+ double white_x, double white_y, double red_x, double red_y, double green_x,
+ double green_y, double blue_x, double blue_y))
+PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr,
+ png_inforp info_ptr, double red_X, double red_Y, double red_Z,
+ double green_X, double green_Y, double green_Z, double blue_X,
+ double blue_Y, double blue_Z))
+PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_fixed_point int_white_x,
+ png_fixed_point int_white_y, png_fixed_point int_red_x,
+ png_fixed_point int_red_y, png_fixed_point int_green_x,
+ png_fixed_point int_green_y, png_fixed_point int_blue_x,
+ png_fixed_point int_blue_y))
+PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,
+ png_fixed_point int_red_Z, png_fixed_point int_green_X,
+ png_fixed_point int_green_Y, png_fixed_point int_green_Z,
+ png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
+ png_fixed_point int_blue_Z))
+#endif
+
+#ifdef PNG_cICP_SUPPORTED
+PNG_EXPORT(250, png_uint_32, png_get_cICP, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr, png_bytep colour_primaries,
+ png_bytep transfer_function, png_bytep matrix_coefficients,
+ png_bytep video_full_range_flag));
+#endif
+
+#ifdef PNG_cICP_SUPPORTED
+PNG_EXPORT(251, void, png_set_cICP, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_byte colour_primaries,
+ png_byte transfer_function, png_byte matrix_coefficients,
+ png_byte video_full_range_flag));
+#endif
+
+#ifdef PNG_cLLI_SUPPORTED
+PNG_FP_EXPORT(252, png_uint_32, png_get_cLLI, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr, double *maximum_content_light_level,
+ double *maximum_frame_average_light_level))
+PNG_FIXED_EXPORT(253, png_uint_32, png_get_cLLI_fixed,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr,
+ /* The values below are in cd/m2 (nits) and are scaled by 10,000; not
+ * 100,000 as in the case of png_fixed_point.
+ */
+ png_uint_32p maximum_content_light_level_scaled_by_10000,
+ png_uint_32p maximum_frame_average_light_level_scaled_by_10000))
+#endif
+
+#ifdef PNG_cLLI_SUPPORTED
+PNG_FP_EXPORT(254, void, png_set_cLLI, (png_const_structrp png_ptr,
+ png_inforp info_ptr, double maximum_content_light_level,
+ double maximum_frame_average_light_level))
+PNG_FIXED_EXPORT(255, void, png_set_cLLI_fixed, (png_const_structrp png_ptr,
+ png_inforp info_ptr,
+ /* The values below are in cd/m2 (nits) and are scaled by 10,000; not
+ * 100,000 as in the case of png_fixed_point.
+ */
+ png_uint_32 maximum_content_light_level_scaled_by_10000,
+ png_uint_32 maximum_frame_average_light_level_scaled_by_10000))
+#endif
+
+#ifdef PNG_eXIf_SUPPORTED
+PNG_EXPORT(246, png_uint_32, png_get_eXIf, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_bytep *exif));
+PNG_EXPORT(247, void, png_set_eXIf, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_bytep exif));
+
+PNG_EXPORT(248, png_uint_32, png_get_eXIf_1, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr, png_uint_32 *num_exif, png_bytep *exif));
+PNG_EXPORT(249, void, png_set_eXIf_1, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 num_exif, png_bytep exif));
+#endif
+
+#ifdef PNG_gAMA_SUPPORTED
+PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr, double *file_gamma))
+PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_fixed_point *int_file_gamma))
+#endif
+
+#ifdef PNG_gAMA_SUPPORTED
+PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr,
+ png_inforp info_ptr, double file_gamma))
+PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_fixed_point int_file_gamma))
+#endif
+
+#ifdef PNG_hIST_SUPPORTED
+PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_uint_16p *hist));
+PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_const_uint_16p hist));
+#endif
+
+PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height,
+ int *bit_depth, int *color_type, int *interlace_method,
+ int *compression_method, int *filter_method));
+
+PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
+ int color_type, int interlace_method, int compression_method,
+ int filter_method));
+
+#ifdef PNG_mDCV_SUPPORTED
+PNG_FP_EXPORT(256, png_uint_32, png_get_mDCV, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr,
+ /* The chromaticities of the mastering display. As cHRM, but independent of
+ * the encoding endpoints in cHRM, or cICP, or iCCP. These values will
+ * always be in the range 0 to 1.3107.
+ */
+ double *white_x, double *white_y, double *red_x, double *red_y,
+ double *green_x, double *green_y, double *blue_x, double *blue_y,
+ /* Mastering display luminance in cd/m2 (nits). */
+ double *mastering_display_maximum_luminance,
+ double *mastering_display_minimum_luminance))
+
+PNG_FIXED_EXPORT(257, png_uint_32, png_get_mDCV_fixed,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_fixed_point *int_white_x, png_fixed_point *int_white_y,
+ png_fixed_point *int_red_x, png_fixed_point *int_red_y,
+ png_fixed_point *int_green_x, png_fixed_point *int_green_y,
+ png_fixed_point *int_blue_x, png_fixed_point *int_blue_y,
+ /* Mastering display luminance in cd/m2 (nits) multiplied (scaled) by
+ * 10,000.
+ */
+ png_uint_32p mastering_display_maximum_luminance_scaled_by_10000,
+ png_uint_32p mastering_display_minimum_luminance_scaled_by_10000))
+#endif
+
+#ifdef PNG_mDCV_SUPPORTED
+PNG_FP_EXPORT(258, void, png_set_mDCV, (png_const_structrp png_ptr,
+ png_inforp info_ptr,
+ /* The chromaticities of the mastering display. As cHRM, but independent of
+ * the encoding endpoints in cHRM, or cICP, or iCCP.
+ */
+ double white_x, double white_y, double red_x, double red_y, double green_x,
+ double green_y, double blue_x, double blue_y,
+ /* Mastering display luminance in cd/m2 (nits). */
+ double mastering_display_maximum_luminance,
+ double mastering_display_minimum_luminance))
+
+PNG_FIXED_EXPORT(259, void, png_set_mDCV_fixed, (png_const_structrp png_ptr,
+ png_inforp info_ptr,
+ /* The admissible range of these values is not the full range of a PNG
+ * fixed point value. Negative values cannot be encoded and the maximum
+ * value is about 1.3 */
+ png_fixed_point int_white_x, png_fixed_point int_white_y,
+ png_fixed_point int_red_x, png_fixed_point int_red_y,
+ png_fixed_point int_green_x, png_fixed_point int_green_y,
+ png_fixed_point int_blue_x, png_fixed_point int_blue_y,
+ /* These are PNG unsigned 4 byte values: 31-bit unsigned values. The MSB
+ * must be zero.
+ */
+ png_uint_32 mastering_display_maximum_luminance_scaled_by_10000,
+ png_uint_32 mastering_display_minimum_luminance_scaled_by_10000))
+#endif
+
+#ifdef PNG_oFFs_SUPPORTED
+PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
+ int *unit_type));
+#endif
+
+#ifdef PNG_oFFs_SUPPORTED
+PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y,
+ int unit_type));
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_charp *purpose, png_int_32 *X0,
+ png_int_32 *X1, int *type, int *nparams, png_charp *units,
+ png_charpp *params));
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1,
+ int type, int nparams, png_const_charp units, png_charpp params));
+#endif
+
+#ifdef PNG_pHYs_SUPPORTED
+PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
+ int *unit_type));
+#endif
+
+#ifdef PNG_pHYs_SUPPORTED
+PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
+#endif
+
+PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_colorp *palette, int *num_palette));
+
+PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr,
+ png_inforp info_ptr, png_const_colorp palette, int num_palette));
+
+#ifdef PNG_sBIT_SUPPORTED
+PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_color_8p *sig_bit));
+#endif
+
+#ifdef PNG_sBIT_SUPPORTED
+PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_const_color_8p sig_bit));
+#endif
+
+#ifdef PNG_sRGB_SUPPORTED
+PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr, int *file_srgb_intent));
+#endif
+
+#ifdef PNG_sRGB_SUPPORTED
+PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr,
+ png_inforp info_ptr, int srgb_intent));
+PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr,
+ png_inforp info_ptr, int srgb_intent));
+#endif
+
+#ifdef PNG_iCCP_SUPPORTED
+PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_charpp name, int *compression_type,
+ png_bytepp profile, png_uint_32 *proflen));
+#endif
+
+#ifdef PNG_iCCP_SUPPORTED
+PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_const_charp name, int compression_type,
+ png_const_bytep profile, png_uint_32 proflen));
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_sPLT_tpp entries));
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_const_sPLT_tp entries, int nentries));
+#endif
+
+#ifdef PNG_TEXT_SUPPORTED
+/* png_get_text also returns the number of text chunks in *num_text */
+PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_textp *text_ptr, int *num_text));
+#endif
+
+/* Note while png_set_text() will accept a structure whose text,
+ * language, and translated keywords are NULL pointers, the structure
+ * returned by png_get_text will always contain regular
+ * zero-terminated C strings. They might be empty strings but
+ * they will never be NULL pointers.
+ */
+
+#ifdef PNG_TEXT_SUPPORTED
+PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_const_textp text_ptr, int num_text));
+#endif
+
+#ifdef PNG_tIME_SUPPORTED
+PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_timep *mod_time));
+#endif
+
+#ifdef PNG_tIME_SUPPORTED
+PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_const_timep mod_time));
+#endif
+
+#ifdef PNG_tRNS_SUPPORTED
+PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans,
+ png_color_16p *trans_color));
+#endif
+
+#ifdef PNG_tRNS_SUPPORTED
+PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr,
+ png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans,
+ png_const_color_16p trans_color));
+#endif
+
+#ifdef PNG_sCAL_SUPPORTED
+PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr, int *unit, double *width, double *height))
+#if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
+ defined(PNG_FLOATING_POINT_SUPPORTED)
+/* NOTE: this API is currently implemented using floating point arithmetic,
+ * consequently it can only be used on systems with floating point support.
+ * In any case the range of values supported by png_fixed_point is small and it
+ * is highly recommended that png_get_sCAL_s be used instead.
+ */
+PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
+ png_fixed_point *width, png_fixed_point *height))
+#endif
+PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
+ png_charpp swidth, png_charpp sheight));
+
+PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr,
+ png_inforp info_ptr, int unit, double width, double height))
+PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr,
+ png_inforp info_ptr, int unit, png_fixed_point width,
+ png_fixed_point height))
+PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,
+ png_inforp info_ptr, int unit,
+ png_const_charp swidth, png_const_charp sheight));
+#endif /* sCAL */
+
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+/* Provide the default handling for all unknown chunks or, optionally, for
+ * specific unknown chunks.
+ *
+ * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was
+ * ignored and the default was used, the per-chunk setting only had an effect on
+ * write. If you wish to have chunk-specific handling on read in code that must
+ * work on earlier versions you must use a user chunk callback to specify the
+ * desired handling (keep or discard.)
+ *
+ * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The
+ * parameter is interpreted as follows:
+ *
+ * READ:
+ * PNG_HANDLE_CHUNK_AS_DEFAULT:
+ * Known chunks: do normal libpng processing, do not keep the chunk (but
+ * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
+ * Unknown chunks: for a specific chunk use the global default, when used
+ * as the default discard the chunk data.
+ * PNG_HANDLE_CHUNK_NEVER:
+ * Discard the chunk data.
+ * PNG_HANDLE_CHUNK_IF_SAFE:
+ * Keep the chunk data if the chunk is not critical else raise a chunk
+ * error.
+ * PNG_HANDLE_CHUNK_ALWAYS:
+ * Keep the chunk data.
+ *
+ * If the chunk data is saved it can be retrieved using png_get_unknown_chunks,
+ * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent
+ * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks
+ * it simply resets the behavior to the libpng default.
+ *
+ * INTERACTION WITH USER CHUNK CALLBACKS:
+ * The per-chunk handling is always used when there is a png_user_chunk_ptr
+ * callback and the callback returns 0; the chunk is then always stored *unless*
+ * it is critical and the per-chunk setting is other than ALWAYS. Notice that
+ * the global default is *not* used in this case. (In effect the per-chunk
+ * value is incremented to at least IF_SAFE.)
+ *
+ * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and
+ * per-chunk defaults will be honored. If you want to preserve the current
+ * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE
+ * as the default - if you don't do this libpng 1.6 will issue a warning.
+ *
+ * If you want unhandled unknown chunks to be discarded in libpng 1.6 and
+ * earlier simply return '1' (handled).
+ *
+ * PNG_HANDLE_AS_UNKNOWN_SUPPORTED:
+ * If this is *not* set known chunks will always be handled by libpng and
+ * will never be stored in the unknown chunk list. Known chunks listed to
+ * png_set_keep_unknown_chunks will have no effect. If it is set then known
+ * chunks listed with a keep other than AS_DEFAULT will *never* be processed
+ * by libpng, in addition critical chunks must either be processed by the
+ * callback or saved.
+ *
+ * The IHDR and IEND chunks must not be listed. Because this turns off the
+ * default handling for chunks that would otherwise be recognized the
+ * behavior of libpng transformations may well become incorrect!
+ *
+ * WRITE:
+ * When writing chunks the options only apply to the chunks specified by
+ * png_set_unknown_chunks (below), libpng will *always* write known chunks
+ * required by png_set_ calls and will always write the core critical chunks
+ * (as required for PLTE).
+ *
+ * Each chunk in the png_set_unknown_chunks list is looked up in the
+ * png_set_keep_unknown_chunks list to find the keep setting, this is then
+ * interpreted as follows:
+ *
+ * PNG_HANDLE_CHUNK_AS_DEFAULT:
+ * Write safe-to-copy chunks and write other chunks if the global
+ * default is set to _ALWAYS, otherwise don't write this chunk.
+ * PNG_HANDLE_CHUNK_NEVER:
+ * Do not write the chunk.
+ * PNG_HANDLE_CHUNK_IF_SAFE:
+ * Write the chunk if it is safe-to-copy, otherwise do not write it.
+ * PNG_HANDLE_CHUNK_ALWAYS:
+ * Write the chunk.
+ *
+ * Note that the default behavior is effectively the opposite of the read case -
+ * in read unknown chunks are not stored by default, in write they are written
+ * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different
+ * - on write the safe-to-copy bit is checked, on read the critical bit is
+ * checked and on read if the chunk is critical an error will be raised.
+ *
+ * num_chunks:
+ * ===========
+ * If num_chunks is positive, then the "keep" parameter specifies the manner
+ * for handling only those chunks appearing in the chunk_list array,
+ * otherwise the chunk list array is ignored.
+ *
+ * If num_chunks is 0 the "keep" parameter specifies the default behavior for
+ * unknown chunks, as described above.
+ *
+ * If num_chunks is negative, then the "keep" parameter specifies the manner
+ * for handling all unknown chunks plus all chunks recognized by libpng
+ * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to
+ * be processed by libpng.
+ */
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr,
+ int keep, png_const_bytep chunk_list, int num_chunks));
+#endif /* HANDLE_AS_UNKNOWN */
+
+/* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned;
+ * the result is therefore true (non-zero) if special handling is required,
+ * false for the default handling.
+ */
+PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr,
+ png_const_bytep chunk_name));
+#endif /* SET_UNKNOWN_CHUNKS */
+
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_const_unknown_chunkp unknowns,
+ int num_unknowns));
+ /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added
+ * unknowns to the location currently stored in the png_struct. This is
+ * invariably the wrong value on write. To fix this call the following API
+ * for each chunk in the list with the correct location. If you know your
+ * code won't be compiled on earlier versions you can rely on
+ * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing
+ * the correct thing.
+ */
+
+PNG_EXPORT(175, void, png_set_unknown_chunk_location,
+ (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location));
+
+PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr,
+ png_inforp info_ptr, png_unknown_chunkpp entries));
+#endif
+
+/* Png_free_data() will turn off the "valid" flag for anything it frees.
+ * If you need to turn it off for a chunk that your application has freed,
+ * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
+ */
+PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr,
+ png_inforp info_ptr, int mask));
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+/* The "params" pointer is currently not used and is for future expansion. */
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr,
+ int transforms, png_voidp params));
+#endif
+#ifdef PNG_WRITE_SUPPORTED
+PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr,
+ int transforms, png_voidp params));
+#endif
+#endif
+
+PNG_EXPORT(180, png_const_charp, png_get_copyright,
+ (png_const_structrp png_ptr));
+PNG_EXPORT(181, png_const_charp, png_get_header_ver,
+ (png_const_structrp png_ptr));
+PNG_EXPORT(182, png_const_charp, png_get_header_version,
+ (png_const_structrp png_ptr));
+PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,
+ (png_const_structrp png_ptr));
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr,
+ png_uint_32 mng_features_permitted));
+#endif
+
+/* For use in png_set_keep_unknown, added to version 1.2.6 */
+#define PNG_HANDLE_CHUNK_AS_DEFAULT 0
+#define PNG_HANDLE_CHUNK_NEVER 1
+#define PNG_HANDLE_CHUNK_IF_SAFE 2
+#define PNG_HANDLE_CHUNK_ALWAYS 3
+#define PNG_HANDLE_CHUNK_LAST 4
+
+/* Strip the prepended error numbers ("#nnn ") from error and warning
+ * messages before passing them to the error or warning handler.
+ */
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr,
+ png_uint_32 strip_mode));
+#endif
+
+/* Added in libpng-1.2.6 */
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr,
+ png_uint_32 user_width_max, png_uint_32 user_height_max));
+PNG_EXPORT(187, png_uint_32, png_get_user_width_max,
+ (png_const_structrp png_ptr));
+PNG_EXPORT(188, png_uint_32, png_get_user_height_max,
+ (png_const_structrp png_ptr));
+/* Added in libpng-1.4.0 */
+PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr,
+ png_uint_32 user_chunk_cache_max));
+PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,
+ (png_const_structrp png_ptr));
+/* Added in libpng-1.4.1 */
+PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr,
+ png_alloc_size_t user_chunk_cache_max));
+PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max,
+ (png_const_structrp png_ptr));
+#endif
+
+#if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
+PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr));
+
+PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr));
+
+PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr));
+
+PNG_FP_EXPORT(196, float, png_get_x_offset_inches,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr))
+#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
+PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr))
+#endif
+
+PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr))
+#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
+PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
+ (png_const_structrp png_ptr, png_const_inforp info_ptr))
+#endif
+
+# ifdef PNG_pHYs_SUPPORTED
+PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr,
+ png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
+ int *unit_type));
+# endif /* pHYs */
+#endif /* INCH_CONVERSIONS */
+
+/* Added in libpng-1.4.0 */
+#ifdef PNG_IO_STATE_SUPPORTED
+PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr));
+
+/* Removed from libpng 1.6; use png_get_io_chunk_type. */
+PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr),
+ PNG_DEPRECATED)
+
+PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
+ (png_const_structrp png_ptr));
+
+/* The flags returned by png_get_io_state() are the following: */
+# define PNG_IO_NONE 0x0000 /* no I/O at this moment */
+# define PNG_IO_READING 0x0001 /* currently reading */
+# define PNG_IO_WRITING 0x0002 /* currently writing */
+# define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
+# define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
+# define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
+# define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
+# define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
+# define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
+#endif /* IO_STATE */
+
+/* Interlace support. The following macros are always defined so that if
+ * libpng interlace handling is turned off the macros may be used to handle
+ * interlaced images within the application.
+ */
+#define PNG_INTERLACE_ADAM7_PASSES 7
+
+/* Two macros to return the first row and first column of the original,
+ * full, image which appears in a given pass. 'pass' is in the range 0
+ * to 6 and the result is in the range 0 to 7.
+ */
+#define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)
+#define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)
+
+/* A macro to return the offset between pixels in the output row for a pair of
+ * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that
+ * follows. Note that ROW_OFFSET is the offset from one row to the next whereas
+ * COL_OFFSET is from one column to the next, within a row.
+ */
+#define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)
+#define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))
+
+/* Two macros to help evaluate the number of rows or columns in each
+ * pass. This is expressed as a shift - effectively log2 of the number or
+ * rows or columns in each 8x8 tile of the original image.
+ */
+#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
+#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
+
+/* Hence two macros to determine the number of rows or columns in a given
+ * pass of an image given its height or width. In fact these macros may
+ * return non-zero even though the sub-image is empty, because the other
+ * dimension may be empty for a small image.
+ */
+#define PNG_PASS_ROWS(height, pass) (((height)+(((1<>PNG_PASS_ROW_SHIFT(pass))
+#define PNG_PASS_COLS(width, pass) (((width)+(((1<>PNG_PASS_COL_SHIFT(pass))
+
+/* For the reader row callbacks (both progressive and sequential) it is
+ * necessary to find the row in the output image given a row in an interlaced
+ * image, so two more macros:
+ */
+#define PNG_ROW_FROM_PASS_ROW(y_in, pass) \
+ (((y_in)<>(((7-(off))-(pass))<<2)) & 0xF) | \
+ ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))
+
+#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
+ ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
+#define PNG_COL_IN_INTERLACE_PASS(x, pass) \
+ ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
+
+#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
+/* With these routines we avoid an integer divide, which will be slower on
+ * most machines. However, it does take more operations than the corresponding
+ * divide method, so it may be slower on a few RISC systems. There are two
+ * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
+ *
+ * Note that the rounding factors are NOT supposed to be the same! 128 and
+ * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
+ * standard method.
+ *
+ * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
+ */
+
+ /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
+
+# define png_composite(composite, fg, alpha, bg) \
+ { \
+ png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
+ * (png_uint_16)(alpha) \
+ + (png_uint_16)(bg)*(png_uint_16)(255 \
+ - (png_uint_16)(alpha)) + 128); \
+ (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \
+ }
+
+# define png_composite_16(composite, fg, alpha, bg) \
+ { \
+ png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
+ * (png_uint_32)(alpha) \
+ + (png_uint_32)(bg)*(65535 \
+ - (png_uint_32)(alpha)) + 32768); \
+ (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \
+ }
+
+#else /* Standard method using integer division */
+
+# define png_composite(composite, fg, alpha, bg) \
+ (composite) = \
+ (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \
+ (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
+ 127) / 255))
+
+# define png_composite_16(composite, fg, alpha, bg) \
+ (composite) = \
+ (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \
+ (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \
+ 32767) / 65535))
+#endif /* READ_COMPOSITE_NODIV */
+
+#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
+PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
+PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));
+PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));
+#endif
+
+PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr,
+ png_const_bytep buf));
+/* No png_get_int_16 -- may be added if there's a real need for it. */
+
+/* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
+#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
+PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));
+#endif
+#ifdef PNG_SAVE_INT_32_SUPPORTED
+PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i));
+#endif
+
+/* Place a 16-bit number into a buffer in PNG byte order.
+ * The parameter is declared unsigned int, not png_uint_16,
+ * just to avoid potential problems on pre-ANSI C compilers.
+ */
+#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
+PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
+/* No png_save_int_16 -- may be added if there's a real need for it. */
+#endif
+
+#ifdef PNG_USE_READ_MACROS
+/* Inline macros to do direct reads of bytes from the input buffer.
+ * The png_get_int_32() routine assumes we are using two's complement
+ * format for negative values, which is almost certainly true.
+ */
+# define PNG_get_uint_32(buf) \
+ (((png_uint_32)(*(buf)) << 24) + \
+ ((png_uint_32)(*((buf) + 1)) << 16) + \
+ ((png_uint_32)(*((buf) + 2)) << 8) + \
+ ((png_uint_32)(*((buf) + 3))))
+
+ /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
+ * function) incorrectly returned a value of type png_uint_32.
+ */
+# define PNG_get_uint_16(buf) \
+ ((png_uint_16) \
+ (((unsigned int)(*(buf)) << 8) + \
+ ((unsigned int)(*((buf) + 1)))))
+
+# define PNG_get_int_32(buf) \
+ ((png_int_32)((*(buf) & 0x80) \
+ ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \
+ : (png_int_32)png_get_uint_32(buf)))
+
+/* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,
+ * but defining a macro name prefixed with PNG_PREFIX.
+ */
+# ifndef PNG_PREFIX
+# define png_get_uint_32(buf) PNG_get_uint_32(buf)
+# define png_get_uint_16(buf) PNG_get_uint_16(buf)
+# define png_get_int_32(buf) PNG_get_int_32(buf)
+# endif
+#else
+# ifdef PNG_PREFIX
+ /* No macros; revert to the (redefined) function */
+# define PNG_get_uint_32 (png_get_uint_32)
+# define PNG_get_uint_16 (png_get_uint_16)
+# define PNG_get_int_32 (png_get_int_32)
+# endif
+#endif
+
+#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+PNG_EXPORT(242, void, png_set_check_for_invalid_index,
+ (png_structrp png_ptr, int allowed));
+# ifdef PNG_GET_PALETTE_MAX_SUPPORTED
+PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr,
+ png_const_infop info_ptr));
+# endif
+#endif /* CHECK_FOR_INVALID_INDEX */
+
+/*******************************************************************************
+ * Section 5: SIMPLIFIED API
+ *******************************************************************************
+ *
+ * Please read the documentation in libpng-manual.txt (TODO: write said
+ * documentation) if you don't understand what follows.
+ *
+ * The simplified API hides the details of both libpng and the PNG file format
+ * itself. It allows PNG files to be read into a very limited number of
+ * in-memory bitmap formats or to be written from the same formats. If these
+ * formats do not accommodate your needs then you can, and should, use the more
+ * sophisticated APIs above - these support a wide variety of in-memory formats
+ * and a wide variety of sophisticated transformations to those formats as well
+ * as a wide variety of APIs to manipulate ancillary information.
+ *
+ * To read a PNG file using the simplified API:
+ *
+ * 1) Declare a 'png_image' structure (see below) on the stack, set the
+ * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
+ * (this is REQUIRED, your program may crash if you don't do it.)
+ * 2) Call the appropriate png_image_begin_read... function.
+ * 3) Set the png_image 'format' member to the required sample format.
+ * 4) Allocate a buffer for the image and, if required, the color-map.
+ * 5) Call png_image_finish_read to read the image and, if required, the
+ * color-map into your buffers.
+ *
+ * There are no restrictions on the format of the PNG input itself; all valid
+ * color types, bit depths, and interlace methods are acceptable, and the
+ * input image is transformed as necessary to the requested in-memory format
+ * during the png_image_finish_read() step. The only caveat is that if you
+ * request a color-mapped image from a PNG that is full-color or makes
+ * complex use of an alpha channel the transformation is extremely lossy and the
+ * result may look terrible.
+ *
+ * To write a PNG file using the simplified API:
+ *
+ * 1) Declare a 'png_image' structure on the stack and memset() it to all zero.
+ * 2) Initialize the members of the structure that describe the image, setting
+ * the 'format' member to the format of the image samples.
+ * 3) Call the appropriate png_image_write... function with a pointer to the
+ * image and, if necessary, the color-map to write the PNG data.
+ *
+ * png_image is a structure that describes the in-memory format of an image
+ * when it is being read or defines the in-memory format of an image that you
+ * need to write:
+ */
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \
+ defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+
+#define PNG_IMAGE_VERSION 1
+
+typedef struct png_control *png_controlp;
+typedef struct
+{
+ png_controlp opaque; /* Initialize to NULL, free with png_image_free */
+ png_uint_32 version; /* Set to PNG_IMAGE_VERSION */
+ png_uint_32 width; /* Image width in pixels (columns) */
+ png_uint_32 height; /* Image height in pixels (rows) */
+ png_uint_32 format; /* Image format as defined below */
+ png_uint_32 flags; /* A bit mask containing informational flags */
+ png_uint_32 colormap_entries;
+ /* Number of entries in the color-map */
+
+ /* In the event of an error or warning the following field will be set to a
+ * non-zero value and the 'message' field will contain a '\0' terminated
+ * string with the libpng error or warning message. If both warnings and
+ * an error were encountered, only the error is recorded. If there
+ * are multiple warnings, only the first one is recorded.
+ *
+ * The upper 30 bits of this value are reserved, the low two bits contain
+ * a value as follows:
+ */
+# define PNG_IMAGE_WARNING 1
+# define PNG_IMAGE_ERROR 2
+ /*
+ * The result is a two-bit code such that a value more than 1 indicates
+ * a failure in the API just called:
+ *
+ * 0 - no warning or error
+ * 1 - warning
+ * 2 - error
+ * 3 - error preceded by warning
+ */
+# define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1)
+
+ png_uint_32 warning_or_error;
+
+ char message[64];
+} png_image, *png_imagep;
+
+/* The samples of the image have one to four channels whose components have
+ * original values in the range 0 to 1.0:
+ *
+ * 1: A single gray or luminance channel (G).
+ * 2: A gray/luminance channel and an alpha channel (GA).
+ * 3: Three red, green, blue color channels (RGB).
+ * 4: Three color channels and an alpha channel (RGBA).
+ *
+ * The components are encoded in one of two ways:
+ *
+ * a) As a small integer, value 0..255, contained in a single byte. For the
+ * alpha channel the original value is simply value/255. For the color or
+ * luminance channels the value is encoded according to the sRGB specification
+ * and matches the 8-bit format expected by typical display devices.
+ *
+ * The color/gray channels are not scaled (pre-multiplied) by the alpha
+ * channel and are suitable for passing to color management software.
+ *
+ * b) As a value in the range 0..65535, contained in a 2-byte integer. All
+ * channels can be converted to the original value by dividing by 65535; all
+ * channels are linear. Color channels use the RGB encoding (RGB end-points) of
+ * the sRGB specification. This encoding is identified by the
+ * PNG_FORMAT_FLAG_LINEAR flag below.
+ *
+ * When the simplified API needs to convert between sRGB and linear colorspaces,
+ * the actual sRGB transfer curve defined in the sRGB specification (see the
+ * article at ) is used, not the gamma=1/2.2
+ * approximation used elsewhere in libpng.
+ *
+ * When an alpha channel is present it is expected to denote pixel coverage
+ * of the color or luminance channels and is returned as an associated alpha
+ * channel: the color/gray channels are scaled (pre-multiplied) by the alpha
+ * value.
+ *
+ * The samples are either contained directly in the image data, between 1 and 8
+ * bytes per pixel according to the encoding, or are held in a color-map indexed
+ * by bytes in the image data. In the case of a color-map the color-map entries
+ * are individual samples, encoded as above, and the image data has one byte per
+ * pixel to select the relevant sample from the color-map.
+ */
+
+/* PNG_FORMAT_*
+ *
+ * #defines to be used in png_image::format. Each #define identifies a
+ * particular layout of sample data and, if present, alpha values. There are
+ * separate defines for each of the two component encodings.
+ *
+ * A format is built up using single bit flag values. All combinations are
+ * valid. Formats can be built up from the flag values or you can use one of
+ * the predefined values below. When testing formats always use the FORMAT_FLAG
+ * macros to test for individual features - future versions of the library may
+ * add new flags.
+ *
+ * When reading or writing color-mapped images the format should be set to the
+ * format of the entries in the color-map then png_image_{read,write}_colormap
+ * called to read or write the color-map and set the format correctly for the
+ * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!
+ *
+ * NOTE: libpng can be built with particular features disabled. If you see
+ * compiler errors because the definition of one of the following flags has been
+ * compiled out it is because libpng does not have the required support. It is
+ * possible, however, for the libpng configuration to enable the format on just
+ * read or just write; in that case you may see an error at run time. You can
+ * guard against this by checking for the definition of the appropriate
+ * "_SUPPORTED" macro, one of:
+ *
+ * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
+ */
+#define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */
+#define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */
+#define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */
+#define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */
+
+#ifdef PNG_FORMAT_BGR_SUPPORTED
+# define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */
+#endif
+
+#ifdef PNG_FORMAT_AFIRST_SUPPORTED
+# define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */
+#endif
+
+#define PNG_FORMAT_FLAG_ASSOCIATED_ALPHA 0x40U /* alpha channel is associated */
+
+/* Commonly used formats have predefined macros.
+ *
+ * First the single byte (sRGB) formats:
+ */
+#define PNG_FORMAT_GRAY 0
+#define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA
+#define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST)
+#define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR
+#define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR)
+#define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA)
+#define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST)
+#define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA)
+#define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST)
+
+/* Then the linear 2-byte formats. When naming these "Y" is used to
+ * indicate a luminance (gray) channel.
+ */
+#define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
+#define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
+#define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
+#define PNG_FORMAT_LINEAR_RGB_ALPHA \
+ (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA)
+
+/* With color-mapped formats the image data is one byte for each pixel, the byte
+ * is an index into the color-map which is formatted as above. To obtain a
+ * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
+ * to one of the above definitions, or you can use one of the definitions below.
+ */
+#define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP)
+#define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP)
+#define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP)
+#define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP)
+#define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP)
+#define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP)
+
+/* PNG_IMAGE macros
+ *
+ * These are convenience macros to derive information from a png_image
+ * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the
+ * actual image sample values - either the entries in the color-map or the
+ * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values
+ * for the pixels and will always return 1 for color-mapped formats. The
+ * remaining macros return information about the rows in the image and the
+ * complete image.
+ *
+ * NOTE: All the macros that take a png_image::format parameter are compile time
+ * constants if the format parameter is, itself, a constant. Therefore these
+ * macros can be used in array declarations and case labels where required.
+ * Similarly the macros are also pre-processor constants (sizeof is not used) so
+ * they can be used in #if tests.
+ *
+ * First the information about the samples.
+ */
+#define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\
+ (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1)
+ /* Return the total number of channels in a given format: 1..4 */
+
+#define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\
+ ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1)
+ /* Return the size in bytes of a single component of a pixel or color-map
+ * entry (as appropriate) in the image: 1 or 2.
+ */
+
+#define PNG_IMAGE_SAMPLE_SIZE(fmt)\
+ (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt))
+ /* This is the size of the sample data for one sample. If the image is
+ * color-mapped it is the size of one color-map entry (and image pixels are
+ * one byte in size), otherwise it is the size of one image pixel.
+ */
+
+#define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\
+ (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)
+ /* The maximum size of the color-map required by the format expressed in a
+ * count of components. This can be used to compile-time allocate a
+ * color-map:
+ *
+ * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
+ *
+ * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
+ *
+ * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
+ * information from one of the png_image_begin_read_ APIs and dynamically
+ * allocate the required memory.
+ */
+
+/* Corresponding information about the pixels */
+#define PNG_IMAGE_PIXEL_(test,fmt)\
+ (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt))
+
+#define PNG_IMAGE_PIXEL_CHANNELS(fmt)\
+ PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt)
+ /* The number of separate channels (components) in a pixel; 1 for a
+ * color-mapped image.
+ */
+
+#define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\
+ PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt)
+ /* The size, in bytes, of each component in a pixel; 1 for a color-mapped
+ * image.
+ */
+
+#define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt)
+ /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */
+
+/* Information about the whole row, or whole image */
+#define PNG_IMAGE_ROW_STRIDE(image)\
+ (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width)
+ /* Return the total number of components in a single row of the image; this
+ * is the minimum 'row stride', the minimum count of components between each
+ * row. For a color-mapped image this is the minimum number of bytes in a
+ * row.
+ *
+ * WARNING: this macro overflows for some images with more than one component
+ * and very large image widths. libpng will refuse to process an image where
+ * this macro would overflow.
+ */
+
+#define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\
+ (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride))
+ /* Return the size, in bytes, of an image buffer given a png_image and a row
+ * stride - the number of components to leave space for in each row.
+ *
+ * WARNING: this macro overflows a 32-bit integer for some large PNG images,
+ * libpng will refuse to process an image where such an overflow would occur.
+ */
+
+#define PNG_IMAGE_SIZE(image)\
+ PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image))
+ /* Return the size, in bytes, of the image in memory given just a png_image;
+ * the row stride is the minimum stride required for the image.
+ */
+
+#define PNG_IMAGE_COLORMAP_SIZE(image)\
+ (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries)
+ /* Return the size, in bytes, of the color-map of this image. If the image
+ * format is not a color-map format this will return a size sufficient for
+ * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if
+ * you don't want to allocate a color-map in this case.
+ */
+
+/* PNG_IMAGE_FLAG_*
+ *
+ * Flags containing additional information about the image are held in the
+ * 'flags' field of png_image.
+ */
+#define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01
+ /* This indicates that the RGB values of the in-memory bitmap do not
+ * correspond to the red, green and blue end-points defined by sRGB.
+ */
+
+#define PNG_IMAGE_FLAG_FAST 0x02
+ /* On write emphasise speed over compression; the resultant PNG file will be
+ * larger but will be produced significantly faster, particular for large
+ * images. Do not use this option for images which will be distributed, only
+ * used it when producing intermediate files that will be read back in
+ * repeatedly. For a typical 24-bit image the option will double the read
+ * speed at the cost of increasing the image size by 25%, however for many
+ * more compressible images the PNG file can be 10 times larger with only a
+ * slight speed gain.
+ */
+
+#define PNG_IMAGE_FLAG_16BIT_sRGB 0x04
+ /* On read if the image is a 16-bit per component image and there is no gAMA
+ * or sRGB chunk assume that the components are sRGB encoded. Notice that
+ * images output by the simplified API always have gamma information; setting
+ * this flag only affects the interpretation of 16-bit images from an
+ * external source. It is recommended that the application expose this flag
+ * to the user; the user can normally easily recognize the difference between
+ * linear and sRGB encoding. This flag has no effect on write - the data
+ * passed to the write APIs must have the correct encoding (as defined
+ * above.)
+ *
+ * If the flag is not set (the default) input 16-bit per component data is
+ * assumed to be linear.
+ *
+ * NOTE: the flag can only be set after the png_image_begin_read_ call,
+ * because that call initializes the 'flags' field.
+ */
+
+#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
+/* READ APIs
+ * ---------
+ *
+ * The png_image passed to the read APIs must have been initialized by setting
+ * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.)
+ */
+#ifdef PNG_STDIO_SUPPORTED
+PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
+ const char *file_name));
+ /* The named file is opened for read and the image header is filled in
+ * from the PNG header in the file.
+ */
+
+PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
+ FILE *file));
+ /* The PNG header is read from the stdio FILE object. */
+#endif /* STDIO */
+
+PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image,
+ png_const_voidp memory, size_t size));
+ /* The PNG header is read from the given memory buffer. */
+
+PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image,
+ png_const_colorp background, void *buffer, png_int_32 row_stride,
+ void *colormap));
+ /* Finish reading the image into the supplied buffer and clean up the
+ * png_image structure.
+ *
+ * row_stride is the step, in byte or 2-byte units as appropriate,
+ * between adjacent rows. A positive stride indicates that the top-most row
+ * is first in the buffer - the normal top-down arrangement. A negative
+ * stride indicates that the bottom-most row is first in the buffer.
+ *
+ * background need only be supplied if an alpha channel must be removed from
+ * a png_byte format and the removal is to be done by compositing on a solid
+ * color; otherwise it may be NULL and any composition will be done directly
+ * onto the buffer. The value is an sRGB color to use for the background,
+ * for grayscale output the green channel is used.
+ *
+ * background must be supplied when an alpha channel must be removed from a
+ * single byte color-mapped output format, in other words if:
+ *
+ * 1) The original format from png_image_begin_read_from_* had
+ * PNG_FORMAT_FLAG_ALPHA set.
+ * 2) The format set by the application does not.
+ * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and
+ * PNG_FORMAT_FLAG_LINEAR *not* set.
+ *
+ * For linear output removing the alpha channel is always done by compositing
+ * on black and background is ignored.
+ *
+ * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must
+ * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE.
+ * image->colormap_entries will be updated to the actual number of entries
+ * written to the colormap; this may be less than the original value.
+ */
+
+PNG_EXPORT(238, void, png_image_free, (png_imagep image));
+ /* Free any data allocated by libpng in image->opaque, setting the pointer to
+ * NULL. May be called at any time after the structure is initialized.
+ */
+#endif /* SIMPLIFIED_READ */
+
+#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
+/* WRITE APIS
+ * ----------
+ * For write you must initialize a png_image structure to describe the image to
+ * be written. To do this use memset to set the whole structure to 0 then
+ * initialize fields describing your image.
+ *
+ * version: must be set to PNG_IMAGE_VERSION
+ * opaque: must be initialized to NULL
+ * width: image width in pixels
+ * height: image height in rows
+ * format: the format of the data (image and color-map) you wish to write
+ * flags: set to 0 unless one of the defined flags applies; set
+ * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB
+ * values do not correspond to the colors in sRGB.
+ * colormap_entries: set to the number of entries in the color-map (0 to 256)
+ */
+#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
+PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image,
+ const char *file, int convert_to_8bit, const void *buffer,
+ png_int_32 row_stride, const void *colormap));
+ /* Write the image to the named file. */
+
+PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
+ int convert_to_8_bit, const void *buffer, png_int_32 row_stride,
+ const void *colormap));
+ /* Write the image to the given FILE object. */
+#endif /* SIMPLIFIED_WRITE_STDIO */
+
+/* With all write APIs if image is in one of the linear formats with 16-bit
+ * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG
+ * gamma encoded according to the sRGB specification, otherwise a 16-bit linear
+ * encoded PNG file is written.
+ *
+ * With color-mapped data formats the colormap parameter point to a color-map
+ * with at least image->colormap_entries encoded in the specified format. If
+ * the format is linear the written PNG color-map will be converted to sRGB
+ * regardless of the convert_to_8_bit flag.
+ *
+ * With all APIs row_stride is handled as in the read APIs - it is the spacing
+ * from one row to the next in component sized units (1 or 2 bytes) and if
+ * negative indicates a bottom-up row layout in the buffer. If row_stride is
+ * zero, libpng will calculate it for you from the image width and number of
+ * channels.
+ *
+ * Note that the write API does not support interlacing, sub-8-bit pixels or
+ * most ancillary chunks. If you need to write text chunks (e.g. for copyright
+ * notices) you need to use one of the other APIs.
+ */
+
+PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory,
+ png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit,
+ const void *buffer, png_int_32 row_stride, const void *colormap));
+ /* Write the image to the given memory buffer. The function both writes the
+ * whole PNG data stream to *memory and updates *memory_bytes with the count
+ * of bytes written.
+ *
+ * 'memory' may be NULL. In this case *memory_bytes is not read however on
+ * success the number of bytes which would have been written will still be
+ * stored in *memory_bytes. On failure *memory_bytes will contain 0.
+ *
+ * If 'memory' is not NULL it must point to memory[*memory_bytes] of
+ * writeable memory.
+ *
+ * If the function returns success memory[*memory_bytes] (if 'memory' is not
+ * NULL) contains the written PNG data. *memory_bytes will always be less
+ * than or equal to the original value.
+ *
+ * If the function returns false and *memory_bytes was not changed an error
+ * occurred during write. If *memory_bytes was changed, or is not 0 if
+ * 'memory' was NULL, the write would have succeeded but for the memory
+ * buffer being too small. *memory_bytes contains the required number of
+ * bytes and will be bigger that the original value.
+ */
+
+#define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\
+ row_stride, colormap)\
+ png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\
+ row_stride, colormap)
+ /* Return the amount of memory in 'size' required to compress this image.
+ * The png_image structure 'image' must be filled in as in the above
+ * function and must not be changed before the actual write call, the buffer
+ * and all other parameters must also be identical to that in the final
+ * write call. The 'size' variable need not be initialized.
+ *
+ * NOTE: the macro returns true/false, if false is returned 'size' will be
+ * set to zero and the write failed and probably will fail if tried again.
+ */
+
+/* You can pre-allocate the buffer by making sure it is of sufficient size
+ * regardless of the amount of compression achieved. The buffer size will
+ * always be bigger than the original image and it will never be filled. The
+ * following macros are provided to assist in allocating the buffer.
+ */
+#define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height)
+ /* The number of uncompressed bytes in the PNG byte encoding of the image;
+ * uncompressing the PNG IDAT data will give this number of bytes.
+ *
+ * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this
+ * macro can because of the extra bytes used in the PNG byte encoding. You
+ * need to avoid this macro if your image size approaches 2^30 in width or
+ * height. The same goes for the remainder of these macros; they all produce
+ * bigger numbers than the actual in-memory image size.
+ */
+#ifndef PNG_ZLIB_MAX_SIZE
+# define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U)
+ /* An upper bound on the number of compressed bytes given 'b' uncompressed
+ * bytes. This is based on deflateBounds() in zlib; different
+ * implementations of zlib compression may conceivably produce more data so
+ * if your zlib implementation is not zlib itself redefine this macro
+ * appropriately.
+ */
+#endif
+
+#define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\
+ PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image))
+ /* An upper bound on the size of the data in the PNG IDAT chunks. */
+
+#define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\
+ ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\
+ (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\
+ 12U+3U*(image).colormap_entries/*PLTE data*/+\
+ (((image).format&PNG_FORMAT_FLAG_ALPHA)?\
+ 12U/*tRNS*/+(image).colormap_entries:0U):0U)+\
+ 12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size))
+ /* A helper for the following macro; if your compiler cannot handle the
+ * following macro use this one with the result of
+ * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most
+ * compilers should handle this just fine.)
+ */
+
+#define PNG_IMAGE_PNG_SIZE_MAX(image)\
+ PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image))
+ /* An upper bound on the total length of the PNG data stream for 'image'.
+ * The result is of type png_alloc_size_t, on 32-bit systems this may
+ * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will
+ * run out of buffer space but return a corrected size which should work.
+ */
+#endif /* SIMPLIFIED_WRITE */
+/*******************************************************************************
+ * END OF SIMPLIFIED API
+ ******************************************************************************/
+#endif /* SIMPLIFIED_{READ|WRITE} */
+
+/*******************************************************************************
+ * Section 6: IMPLEMENTATION OPTIONS
+ *******************************************************************************
+ *
+ * Support for arbitrary implementation-specific optimizations. The API allows
+ * particular options to be turned on or off. 'Option' is the number of the
+ * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given
+ * by the PNG_OPTION_ defines below.
+ *
+ * HARDWARE: normally hardware capabilities, such as the Intel SSE instructions,
+ * are detected at run time, however sometimes it may be impossible
+ * to do this in user mode, in which case it is necessary to discover
+ * the capabilities in an OS specific way. Such capabilities are
+ * listed here when libpng has support for them and must be turned
+ * ON by the application if present.
+ *
+ * SOFTWARE: sometimes software optimizations actually result in performance
+ * decrease on some architectures or systems, or with some sets of
+ * PNG images. 'Software' options allow such optimizations to be
+ * selected at run time.
+ */
+#ifdef PNG_SET_OPTION_SUPPORTED
+#ifdef PNG_ARM_NEON_API_SUPPORTED
+# define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */
+#endif
+#define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
+#define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */
+#ifdef PNG_MIPS_MSA_API_SUPPORTED
+# define PNG_MIPS_MSA 6 /* HARDWARE: MIPS Msa SIMD instructions supported */
+#endif
+#ifdef PNG_DISABLE_ADLER32_CHECK_SUPPORTED
+# define PNG_IGNORE_ADLER32 8 /* SOFTWARE: disable Adler32 check on IDAT */
+#endif
+#ifdef PNG_POWERPC_VSX_API_SUPPORTED
+# define PNG_POWERPC_VSX 10 /* HARDWARE: PowerPC VSX SIMD instructions
+ * supported */
+#endif
+#ifdef PNG_MIPS_MMI_API_SUPPORTED
+# define PNG_MIPS_MMI 12 /* HARDWARE: MIPS MMI SIMD instructions supported */
+#endif
+
+#ifdef PNG_RISCV_RVV_API_SUPPORTED
+# define PNG_RISCV_RVV 14 /* HARDWARE: RISC-V RVV SIMD instructions supported */
+#endif
+
+#define PNG_OPTION_NEXT 16 /* Next option - numbers must be even */
+
+/* Return values: NOTE: there are four values and 'off' is *not* zero */
+#define PNG_OPTION_UNSET 0 /* Unset - defaults to off */
+#define PNG_OPTION_INVALID 1 /* Option number out of range */
+#define PNG_OPTION_OFF 2
+#define PNG_OPTION_ON 3
+
+PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
+ int onoff));
+#endif /* SET_OPTION */
+
+/*******************************************************************************
+ * END OF HARDWARE AND SOFTWARE OPTIONS
+ ******************************************************************************/
+
+/* Maintainer: Put new public prototypes here ^, in libpng.3, in project
+ * defs, and in scripts/symbols.def.
+ */
+
+/* The last ordinal number (this is the *last* one already used; the next
+ * one to use is one more than this.)
+ */
+#ifdef PNG_EXPORT_LAST_ORDINAL
+ PNG_EXPORT_LAST_ORDINAL(259);
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* PNG_VERSION_INFO_ONLY */
+/* Do not put anything past this line */
+#endif /* PNG_H */
diff --git a/libs/imagequant/external/libpng/pngconf.h b/libs/imagequant/external/libpng/pngconf.h
new file mode 100644
index 00000000..f08dc47c
--- /dev/null
+++ b/libs/imagequant/external/libpng/pngconf.h
@@ -0,0 +1,615 @@
+/* pngconf.h - machine-configurable file for libpng
+ *
+ * libpng version 1.6.49.git
+ *
+ * Copyright (c) 2018-2025 Cosmin Truta
+ * Copyright (c) 1998-2002,2004,2006-2016,2018 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * Any machine specific code is near the front of this file, so if you
+ * are configuring libpng for a machine, you may want to read the section
+ * starting here down to where it starts to typedef png_color, png_text,
+ * and png_info.
+ */
+
+#ifndef PNGCONF_H
+#define PNGCONF_H
+
+#ifndef PNG_BUILDING_SYMBOL_TABLE /* else includes may cause problems */
+
+/* From libpng 1.6.0 libpng requires an ANSI X3.159-1989 ("ISOC90") compliant C
+ * compiler for correct compilation. The following header files are required by
+ * the standard. If your compiler doesn't provide these header files, or they
+ * do not match the standard, you will need to provide/improve them.
+ */
+#include
+#include
+
+/* Library header files. These header files are all defined by ISOC90; libpng
+ * expects conformant implementations, however, an ISOC90 conformant system need
+ * not provide these header files if the functionality cannot be implemented.
+ * In this case it will be necessary to disable the relevant parts of libpng in
+ * the build of pnglibconf.h.
+ *
+ * Prior to 1.6.0 string.h was included here; the API changes in 1.6.0 to not
+ * include this unnecessary header file.
+ */
+
+#ifdef PNG_STDIO_SUPPORTED
+ /* Required for the definition of FILE: */
+# include
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+ /* Required for the definition of jmp_buf and the declaration of longjmp: */
+# include
+#endif
+
+#ifdef PNG_CONVERT_tIME_SUPPORTED
+ /* Required for struct tm: */
+# include
+#endif
+
+#endif /* PNG_BUILDING_SYMBOL_TABLE */
+
+/* Prior to 1.6.0, it was possible to turn off 'const' in declarations,
+ * using PNG_NO_CONST. This is no longer supported.
+ */
+#define PNG_CONST const /* backward compatibility only */
+
+/* This controls optimization of the reading of 16-bit and 32-bit
+ * values from PNG files. It can be set on a per-app-file basis: it
+ * just changes whether a macro is used when the function is called.
+ * The library builder sets the default; if read functions are not
+ * built into the library the macro implementation is forced on.
+ */
+#ifndef PNG_READ_INT_FUNCTIONS_SUPPORTED
+# define PNG_USE_READ_MACROS
+#endif
+#if !defined(PNG_NO_USE_READ_MACROS) && !defined(PNG_USE_READ_MACROS)
+# if PNG_DEFAULT_READ_MACROS
+# define PNG_USE_READ_MACROS
+# endif
+#endif
+
+/* COMPILER SPECIFIC OPTIONS.
+ *
+ * These options are provided so that a variety of difficult compilers
+ * can be used. Some are fixed at build time (e.g. PNG_API_RULE
+ * below) but still have compiler specific implementations, others
+ * may be changed on a per-file basis when compiling against libpng.
+ */
+
+/* The PNGARG macro was used in versions of libpng prior to 1.6.0 to protect
+ * against legacy (pre ISOC90) compilers that did not understand function
+ * prototypes. [Deprecated.]
+ */
+#ifndef PNGARG
+# define PNGARG(arglist) arglist
+#endif
+
+/* Function calling conventions.
+ * =============================
+ * Normally it is not necessary to specify to the compiler how to call
+ * a function - it just does it - however on x86 systems derived from
+ * Microsoft and Borland C compilers ('IBM PC', 'DOS', 'Windows' systems
+ * and some others) there are multiple ways to call a function and the
+ * default can be changed on the compiler command line. For this reason
+ * libpng specifies the calling convention of every exported function and
+ * every function called via a user supplied function pointer. This is
+ * done in this file by defining the following macros:
+ *
+ * PNGAPI Calling convention for exported functions.
+ * PNGCBAPI Calling convention for user provided (callback) functions.
+ * PNGCAPI Calling convention used by the ANSI-C library (required
+ * for longjmp callbacks and sometimes used internally to
+ * specify the calling convention for zlib).
+ *
+ * These macros should never be overridden. If it is necessary to
+ * change calling convention in a private build this can be done
+ * by setting PNG_API_RULE (which defaults to 0) to one of the values
+ * below to select the correct 'API' variants.
+ *
+ * PNG_API_RULE=0 Use PNGCAPI - the 'C' calling convention - throughout.
+ * This is correct in every known environment.
+ * PNG_API_RULE=1 Use the operating system convention for PNGAPI and
+ * the 'C' calling convention (from PNGCAPI) for
+ * callbacks (PNGCBAPI). This is no longer required
+ * in any known environment - if it has to be used
+ * please post an explanation of the problem to the
+ * libpng mailing list.
+ *
+ * These cases only differ if the operating system does not use the C
+ * calling convention, at present this just means the above cases
+ * (x86 DOS/Windows systems) and, even then, this does not apply to
+ * Cygwin running on those systems.
+ *
+ * Note that the value must be defined in pnglibconf.h so that what
+ * the application uses to call the library matches the conventions
+ * set when building the library.
+ */
+
+/* Symbol export
+ * =============
+ * When building a shared library it is almost always necessary to tell
+ * the compiler which symbols to export. The png.h macro 'PNG_EXPORT'
+ * is used to mark the symbols. On some systems these symbols can be
+ * extracted at link time and need no special processing by the compiler,
+ * on other systems the symbols are flagged by the compiler and just
+ * the declaration requires a special tag applied (unfortunately) in a
+ * compiler dependent way. Some systems can do either.
+ *
+ * A small number of older systems also require a symbol from a DLL to
+ * be flagged to the program that calls it. This is a problem because
+ * we do not know in the header file included by application code that
+ * the symbol will come from a shared library, as opposed to a statically
+ * linked one. For this reason the application must tell us by setting
+ * the magic flag PNG_USE_DLL to turn on the special processing before
+ * it includes png.h.
+ *
+ * Four additional macros are used to make this happen:
+ *
+ * PNG_IMPEXP The magic (if any) to cause a symbol to be exported from
+ * the build or imported if PNG_USE_DLL is set - compiler
+ * and system specific.
+ *
+ * PNG_EXPORT_TYPE(type) A macro that pre or appends PNG_IMPEXP to
+ * 'type', compiler specific.
+ *
+ * PNG_DLL_EXPORT Set to the magic to use during a libpng build to
+ * make a symbol exported from the DLL. Not used in the
+ * public header files; see pngpriv.h for how it is used
+ * in the libpng build.
+ *
+ * PNG_DLL_IMPORT Set to the magic to force the libpng symbols to come
+ * from a DLL - used to define PNG_IMPEXP when
+ * PNG_USE_DLL is set.
+ */
+
+/* System specific discovery.
+ * ==========================
+ * This code is used at build time to find PNG_IMPEXP, the API settings
+ * and PNG_EXPORT_TYPE(), it may also set a macro to indicate the DLL
+ * import processing is possible. On Windows systems it also sets
+ * compiler-specific macros to the values required to change the calling
+ * conventions of the various functions.
+ */
+#if defined(_WIN32) || defined(__WIN32__) || defined(__NT__) || \
+ defined(__CYGWIN__)
+ /* Windows system (DOS doesn't support DLLs). Includes builds under Cygwin or
+ * MinGW on any architecture currently supported by Windows. Also includes
+ * Watcom builds but these need special treatment because they are not
+ * compatible with GCC or Visual C because of different calling conventions.
+ */
+# if PNG_API_RULE == 2
+ /* If this line results in an error, either because __watcall is not
+ * understood or because of a redefine just below you cannot use *this*
+ * build of the library with the compiler you are using. *This* build was
+ * build using Watcom and applications must also be built using Watcom!
+ */
+# define PNGCAPI __watcall
+# endif
+
+# if defined(__GNUC__) || (defined(_MSC_VER) && (_MSC_VER >= 800))
+# define PNGCAPI __cdecl
+# if PNG_API_RULE == 1
+ /* If this line results in an error __stdcall is not understood and
+ * PNG_API_RULE should not have been set to '1'.
+ */
+# define PNGAPI __stdcall
+# endif
+# else
+ /* An older compiler, or one not detected (erroneously) above,
+ * if necessary override on the command line to get the correct
+ * variants for the compiler.
+ */
+# ifndef PNGCAPI
+# define PNGCAPI _cdecl
+# endif
+# if PNG_API_RULE == 1 && !defined(PNGAPI)
+# define PNGAPI _stdcall
+# endif
+# endif /* compiler/api */
+
+ /* NOTE: PNGCBAPI always defaults to PNGCAPI. */
+
+# if defined(PNGAPI) && !defined(PNG_USER_PRIVATEBUILD)
+# error PNG_USER_PRIVATEBUILD must be defined if PNGAPI is changed
+# endif
+
+# define PNG_DLL_EXPORT __declspec(dllexport)
+# ifndef PNG_DLL_IMPORT
+# define PNG_DLL_IMPORT __declspec(dllimport)
+# endif
+
+#else /* !Windows */
+# if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__)
+# define PNGAPI _System
+# else /* !Windows/x86 && !OS/2 */
+ /* Use the defaults, or define PNG*API on the command line (but
+ * this will have to be done for every compile!)
+ */
+# endif /* other system, !OS/2 */
+#endif /* !Windows/x86 */
+
+/* Now do all the defaulting . */
+#ifndef PNGCAPI
+# define PNGCAPI
+#endif
+#ifndef PNGCBAPI
+# define PNGCBAPI PNGCAPI
+#endif
+#ifndef PNGAPI
+# define PNGAPI PNGCAPI
+#endif
+
+/* PNG_IMPEXP may be set on the compilation system command line or (if not set)
+ * then in an internal header file when building the library, otherwise (when
+ * using the library) it is set here.
+ */
+#ifndef PNG_IMPEXP
+# if defined(PNG_USE_DLL) && defined(PNG_DLL_IMPORT)
+ /* This forces use of a DLL, disallowing static linking */
+# define PNG_IMPEXP PNG_DLL_IMPORT
+# endif
+
+# ifndef PNG_IMPEXP
+# define PNG_IMPEXP
+# endif
+#endif
+
+/* In 1.5.2 the definition of PNG_FUNCTION has been changed to always treat
+ * 'attributes' as a storage class - the attributes go at the start of the
+ * function definition, and attributes are always appended regardless of the
+ * compiler. This considerably simplifies these macros but may cause problems
+ * if any compilers both need function attributes and fail to handle them as
+ * a storage class (this is unlikely.)
+ */
+#ifndef PNG_FUNCTION
+# define PNG_FUNCTION(type, name, args, attributes) attributes type name args
+#endif
+
+#ifndef PNG_EXPORT_TYPE
+# define PNG_EXPORT_TYPE(type) PNG_IMPEXP type
+#endif
+
+ /* The ordinal value is only relevant when preprocessing png.h for symbol
+ * table entries, so we discard it here. See the .dfn files in the
+ * scripts directory.
+ */
+
+#ifndef PNG_EXPORTA
+# define PNG_EXPORTA(ordinal, type, name, args, attributes) \
+ PNG_FUNCTION(PNG_EXPORT_TYPE(type), (PNGAPI name), args, \
+ PNG_LINKAGE_API attributes)
+#endif
+
+/* ANSI-C (C90) does not permit a macro to be invoked with an empty argument,
+ * so make something non-empty to satisfy the requirement:
+ */
+#define PNG_EMPTY /*empty list*/
+
+#define PNG_EXPORT(ordinal, type, name, args) \
+ PNG_EXPORTA(ordinal, type, name, args, PNG_EMPTY)
+
+/* Use PNG_REMOVED to comment out a removed interface. */
+#ifndef PNG_REMOVED
+# define PNG_REMOVED(ordinal, type, name, args, attributes)
+#endif
+
+#ifndef PNG_CALLBACK
+# define PNG_CALLBACK(type, name, args) type (PNGCBAPI name) args
+#endif
+
+/* Support for compiler specific function attributes. These are used
+ * so that where compiler support is available incorrect use of API
+ * functions in png.h will generate compiler warnings.
+ *
+ * Added at libpng-1.2.41.
+ */
+
+#ifndef PNG_NO_PEDANTIC_WARNINGS
+# ifndef PNG_PEDANTIC_WARNINGS_SUPPORTED
+# define PNG_PEDANTIC_WARNINGS_SUPPORTED
+# endif
+#endif
+
+#ifdef PNG_PEDANTIC_WARNINGS_SUPPORTED
+ /* Support for compiler specific function attributes. These are used
+ * so that where compiler support is available, incorrect use of API
+ * functions in png.h will generate compiler warnings. Added at libpng
+ * version 1.2.41. Disabling these removes the warnings but may also produce
+ * less efficient code.
+ */
+# if defined(__clang__) && defined(__has_attribute)
+ /* Clang defines both __clang__ and __GNUC__. Check __clang__ first. */
+# if !defined(PNG_USE_RESULT) && __has_attribute(__warn_unused_result__)
+# define PNG_USE_RESULT __attribute__((__warn_unused_result__))
+# endif
+# if !defined(PNG_NORETURN) && __has_attribute(__noreturn__)
+# define PNG_NORETURN __attribute__((__noreturn__))
+# endif
+# if !defined(PNG_ALLOCATED) && __has_attribute(__malloc__)
+# define PNG_ALLOCATED __attribute__((__malloc__))
+# endif
+# if !defined(PNG_DEPRECATED) && __has_attribute(__deprecated__)
+# define PNG_DEPRECATED __attribute__((__deprecated__))
+# endif
+# if !defined(PNG_PRIVATE)
+# ifdef __has_extension
+# if __has_extension(attribute_unavailable_with_message)
+# define PNG_PRIVATE __attribute__((__unavailable__(\
+ "This function is not exported by libpng.")))
+# endif
+# endif
+# endif
+# ifndef PNG_RESTRICT
+# define PNG_RESTRICT __restrict
+# endif
+
+# elif defined(__GNUC__)
+# ifndef PNG_USE_RESULT
+# define PNG_USE_RESULT __attribute__((__warn_unused_result__))
+# endif
+# ifndef PNG_NORETURN
+# define PNG_NORETURN __attribute__((__noreturn__))
+# endif
+# if __GNUC__ >= 3
+# ifndef PNG_ALLOCATED
+# define PNG_ALLOCATED __attribute__((__malloc__))
+# endif
+# ifndef PNG_DEPRECATED
+# define PNG_DEPRECATED __attribute__((__deprecated__))
+# endif
+# ifndef PNG_PRIVATE
+# if 0 /* Doesn't work so we use deprecated instead*/
+# define PNG_PRIVATE \
+ __attribute__((warning("This function is not exported by libpng.")))
+# else
+# define PNG_PRIVATE \
+ __attribute__((__deprecated__))
+# endif
+# endif
+# if ((__GNUC__ > 3) || !defined(__GNUC_MINOR__) || (__GNUC_MINOR__ >= 1))
+# ifndef PNG_RESTRICT
+# define PNG_RESTRICT __restrict
+# endif
+# endif /* __GNUC__.__GNUC_MINOR__ > 3.0 */
+# endif /* __GNUC__ >= 3 */
+
+# elif defined(_MSC_VER) && (_MSC_VER >= 1300)
+# ifndef PNG_USE_RESULT
+# define PNG_USE_RESULT /* not supported */
+# endif
+# ifndef PNG_NORETURN
+# define PNG_NORETURN __declspec(noreturn)
+# endif
+# ifndef PNG_ALLOCATED
+# if (_MSC_VER >= 1400)
+# define PNG_ALLOCATED __declspec(restrict)
+# endif
+# endif
+# ifndef PNG_DEPRECATED
+# define PNG_DEPRECATED __declspec(deprecated)
+# endif
+# ifndef PNG_PRIVATE
+# define PNG_PRIVATE __declspec(deprecated)
+# endif
+# ifndef PNG_RESTRICT
+# if (_MSC_VER >= 1400)
+# define PNG_RESTRICT __restrict
+# endif
+# endif
+
+# elif defined(__WATCOMC__)
+# ifndef PNG_RESTRICT
+# define PNG_RESTRICT __restrict
+# endif
+# endif
+#endif /* PNG_PEDANTIC_WARNINGS */
+
+#ifndef PNG_DEPRECATED
+# define PNG_DEPRECATED /* Use of this function is deprecated */
+#endif
+#ifndef PNG_USE_RESULT
+# define PNG_USE_RESULT /* The result of this function must be checked */
+#endif
+#ifndef PNG_NORETURN
+# define PNG_NORETURN /* This function does not return */
+#endif
+#ifndef PNG_ALLOCATED
+# define PNG_ALLOCATED /* The result of the function is new memory */
+#endif
+#ifndef PNG_PRIVATE
+# define PNG_PRIVATE /* This is a private libpng function */
+#endif
+#ifndef PNG_RESTRICT
+# define PNG_RESTRICT /* The C99 "restrict" feature */
+#endif
+
+#ifndef PNG_FP_EXPORT /* A floating point API. */
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+# define PNG_FP_EXPORT(ordinal, type, name, args)\
+ PNG_EXPORT(ordinal, type, name, args);
+# else /* No floating point APIs */
+# define PNG_FP_EXPORT(ordinal, type, name, args)
+# endif
+#endif
+#ifndef PNG_FIXED_EXPORT /* A fixed point API. */
+# ifdef PNG_FIXED_POINT_SUPPORTED
+# define PNG_FIXED_EXPORT(ordinal, type, name, args)\
+ PNG_EXPORT(ordinal, type, name, args);
+# else /* No fixed point APIs */
+# define PNG_FIXED_EXPORT(ordinal, type, name, args)
+# endif
+#endif
+
+#ifndef PNG_BUILDING_SYMBOL_TABLE
+/* Some typedefs to get us started. These should be safe on most of the common
+ * platforms.
+ *
+ * png_uint_32 and png_int_32 may, currently, be larger than required to hold a
+ * 32-bit value however this is not normally advisable.
+ *
+ * png_uint_16 and png_int_16 should always be two bytes in size - this is
+ * verified at library build time.
+ *
+ * png_byte must always be one byte in size.
+ *
+ * The checks below use constants from limits.h, as defined by the ISOC90
+ * standard.
+ */
+#if CHAR_BIT == 8 && UCHAR_MAX == 255
+ typedef unsigned char png_byte;
+#else
+# error libpng requires 8-bit bytes
+#endif
+
+#if INT_MIN == -32768 && INT_MAX == 32767
+ typedef int png_int_16;
+#elif SHRT_MIN == -32768 && SHRT_MAX == 32767
+ typedef short png_int_16;
+#else
+# error libpng requires a signed 16-bit integer type
+#endif
+
+#if UINT_MAX == 65535
+ typedef unsigned int png_uint_16;
+#elif USHRT_MAX == 65535
+ typedef unsigned short png_uint_16;
+#else
+# error libpng requires an unsigned 16-bit integer type
+#endif
+
+#if INT_MIN < -2147483646 && INT_MAX > 2147483646
+ typedef int png_int_32;
+#elif LONG_MIN < -2147483646 && LONG_MAX > 2147483646
+ typedef long int png_int_32;
+#else
+# error libpng requires a signed 32-bit (or longer) integer type
+#endif
+
+#if UINT_MAX > 4294967294U
+ typedef unsigned int png_uint_32;
+#elif ULONG_MAX > 4294967294U
+ typedef unsigned long int png_uint_32;
+#else
+# error libpng requires an unsigned 32-bit (or longer) integer type
+#endif
+
+/* Prior to 1.6.0, it was possible to disable the use of size_t and ptrdiff_t.
+ * From 1.6.0 onwards, an ISO C90 compiler, as well as a standard-compliant
+ * behavior of sizeof and ptrdiff_t are required.
+ * The legacy typedefs are provided here for backwards compatibility.
+ */
+typedef size_t png_size_t;
+typedef ptrdiff_t png_ptrdiff_t;
+
+/* libpng needs to know the maximum value of 'size_t' and this controls the
+ * definition of png_alloc_size_t, below. This maximum value of size_t limits
+ * but does not control the maximum allocations the library makes - there is
+ * direct application control of this through png_set_user_limits().
+ */
+#ifndef PNG_SMALL_SIZE_T
+ /* Compiler specific tests for systems where size_t is known to be less than
+ * 32 bits (some of these systems may no longer work because of the lack of
+ * 'far' support; see above.)
+ */
+# if (defined(__TURBOC__) && !defined(__FLAT__)) ||\
+ (defined(_MSC_VER) && defined(MAXSEG_64K))
+# define PNG_SMALL_SIZE_T
+# endif
+#endif
+
+/* png_alloc_size_t is guaranteed to be no smaller than size_t, and no smaller
+ * than png_uint_32. Casts from size_t or png_uint_32 to png_alloc_size_t are
+ * not necessary; in fact, it is recommended not to use them at all, so that
+ * the compiler can complain when something turns out to be problematic.
+ *
+ * Casts in the other direction (from png_alloc_size_t to size_t or
+ * png_uint_32) should be explicitly applied; however, we do not expect to
+ * encounter practical situations that require such conversions.
+ *
+ * PNG_SMALL_SIZE_T must be defined if the maximum value of size_t is less than
+ * 4294967295 - i.e. less than the maximum value of png_uint_32.
+ */
+#ifdef PNG_SMALL_SIZE_T
+ typedef png_uint_32 png_alloc_size_t;
+#else
+ typedef size_t png_alloc_size_t;
+#endif
+
+/* Prior to 1.6.0 libpng offered limited support for Microsoft C compiler
+ * implementations of Intel CPU specific support of user-mode segmented address
+ * spaces, where 16-bit pointers address more than 65536 bytes of memory using
+ * separate 'segment' registers. The implementation requires two different
+ * types of pointer (only one of which includes the segment value.)
+ *
+ * If required this support is available in version 1.2 of libpng and may be
+ * available in versions through 1.5, although the correctness of the code has
+ * not been verified recently.
+ */
+
+/* Typedef for floating-point numbers that are converted to fixed-point with a
+ * multiple of 100,000, e.g., gamma
+ */
+typedef png_int_32 png_fixed_point;
+
+/* Add typedefs for pointers */
+typedef void * png_voidp;
+typedef const void * png_const_voidp;
+typedef png_byte * png_bytep;
+typedef const png_byte * png_const_bytep;
+typedef png_uint_32 * png_uint_32p;
+typedef const png_uint_32 * png_const_uint_32p;
+typedef png_int_32 * png_int_32p;
+typedef const png_int_32 * png_const_int_32p;
+typedef png_uint_16 * png_uint_16p;
+typedef const png_uint_16 * png_const_uint_16p;
+typedef png_int_16 * png_int_16p;
+typedef const png_int_16 * png_const_int_16p;
+typedef char * png_charp;
+typedef const char * png_const_charp;
+typedef png_fixed_point * png_fixed_point_p;
+typedef const png_fixed_point * png_const_fixed_point_p;
+typedef size_t * png_size_tp;
+typedef const size_t * png_const_size_tp;
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+typedef double * png_doublep;
+typedef const double * png_const_doublep;
+#endif
+
+/* Pointers to pointers; i.e. arrays */
+typedef png_byte * * png_bytepp;
+typedef png_uint_32 * * png_uint_32pp;
+typedef png_int_32 * * png_int_32pp;
+typedef png_uint_16 * * png_uint_16pp;
+typedef png_int_16 * * png_int_16pp;
+typedef const char * * png_const_charpp;
+typedef char * * png_charpp;
+typedef png_fixed_point * * png_fixed_point_pp;
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+typedef double * * png_doublepp;
+#endif
+
+/* Pointers to pointers to pointers; i.e., pointer to array */
+typedef char * * * png_charppp;
+
+#ifdef PNG_STDIO_SUPPORTED
+/* With PNG_STDIO_SUPPORTED it was possible to use I/O streams that were
+ * not necessarily stdio FILE streams, to allow building Windows applications
+ * before Win32 and Windows CE applications before WinCE 3.0, but that kind
+ * of support has long been discontinued.
+ */
+typedef FILE * png_FILE_p; /* [Deprecated] */
+#endif
+
+#endif /* PNG_BUILDING_SYMBOL_TABLE */
+
+#endif /* PNGCONF_H */
diff --git a/libs/imagequant/external/libpng/pngdebug.h b/libs/imagequant/external/libpng/pngdebug.h
new file mode 100644
index 00000000..af1ae9e8
--- /dev/null
+++ b/libs/imagequant/external/libpng/pngdebug.h
@@ -0,0 +1,156 @@
+/* pngdebug.h - internal debugging macros for libpng
+ *
+ * Copyright (c) 2018-2025 Cosmin Truta
+ * Copyright (c) 1998-2002,2004,2006-2013 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#ifndef PNGPRIV_H
+# error This file must not be included by applications; please include
+#endif
+
+/* Define PNG_DEBUG at compile time for debugging information. Higher
+ * numbers for PNG_DEBUG mean more debugging information. This has
+ * only been added since version 0.95 so it is not implemented throughout
+ * libpng yet, but more support will be added as needed.
+ *
+ * png_debug[1-2]?(level, message ,arg{0-2})
+ * Expands to a statement (either a simple expression or a compound
+ * do..while(0) statement) that outputs a message with parameter
+ * substitution if PNG_DEBUG is defined to 2 or more. If PNG_DEBUG
+ * is undefined, 0 or 1 every png_debug expands to a simple expression
+ * (actually ((void)0)).
+ *
+ * level: level of detail of message, starting at 0. A level 'n'
+ * message is preceded by 'n' 3-space indentations (not implemented
+ * on Microsoft compilers unless PNG_DEBUG_FILE is also
+ * defined, to allow debug DLL compilation with no standard IO).
+ * message: a printf(3) style text string. A trailing '\n' is added
+ * to the message.
+ * arg: 0 to 2 arguments for printf(3) style substitution in message.
+ */
+#ifndef PNGDEBUG_H
+#define PNGDEBUG_H
+/* These settings control the formatting of messages in png.c and pngerror.c */
+/* Moved to pngdebug.h at 1.5.0 */
+# ifndef PNG_LITERAL_SHARP
+# define PNG_LITERAL_SHARP 0x23
+# endif
+# ifndef PNG_LITERAL_LEFT_SQUARE_BRACKET
+# define PNG_LITERAL_LEFT_SQUARE_BRACKET 0x5b
+# endif
+# ifndef PNG_LITERAL_RIGHT_SQUARE_BRACKET
+# define PNG_LITERAL_RIGHT_SQUARE_BRACKET 0x5d
+# endif
+# ifndef PNG_STRING_NEWLINE
+# define PNG_STRING_NEWLINE "\n"
+# endif
+
+#ifdef PNG_DEBUG
+# if (PNG_DEBUG > 0)
+# if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
+# include
+# if (PNG_DEBUG > 1)
+# ifndef _DEBUG
+# define _DEBUG
+# endif
+# ifndef png_debug
+# define png_debug(l,m) _RPT0(_CRT_WARN,m PNG_STRING_NEWLINE)
+# endif
+# ifndef png_debug1
+# define png_debug1(l,m,p1) _RPT1(_CRT_WARN,m PNG_STRING_NEWLINE,p1)
+# endif
+# ifndef png_debug2
+# define png_debug2(l,m,p1,p2) \
+ _RPT2(_CRT_WARN,m PNG_STRING_NEWLINE,p1,p2)
+# endif
+# endif
+# else /* PNG_DEBUG_FILE || !_MSC_VER */
+# ifndef PNG_STDIO_SUPPORTED
+# include /* not included yet */
+# endif
+# ifndef PNG_DEBUG_FILE
+# define PNG_DEBUG_FILE stderr
+# endif /* PNG_DEBUG_FILE */
+
+# if (PNG_DEBUG > 1)
+# ifdef __STDC__
+# ifndef png_debug
+# define png_debug(l,m) \
+ do { \
+ int num_tabs=l; \
+ fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? " " : \
+ (num_tabs==2 ? " " : (num_tabs>2 ? " " : "")))); \
+ } while (0)
+# endif
+# ifndef png_debug1
+# define png_debug1(l,m,p1) \
+ do { \
+ int num_tabs=l; \
+ fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? " " : \
+ (num_tabs==2 ? " " : (num_tabs>2 ? " " : ""))),p1); \
+ } while (0)
+# endif
+# ifndef png_debug2
+# define png_debug2(l,m,p1,p2) \
+ do { \
+ int num_tabs=l; \
+ fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? " " : \
+ (num_tabs==2 ? " " : (num_tabs>2 ? " " : ""))),p1,p2);\
+ } while (0)
+# endif
+# else /* __STDC __ */
+# ifndef png_debug
+# define png_debug(l,m) \
+ do { \
+ int num_tabs=l; \
+ char format[256]; \
+ snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
+ (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
+ m,PNG_STRING_NEWLINE); \
+ fprintf(PNG_DEBUG_FILE,format); \
+ } while (0)
+# endif
+# ifndef png_debug1
+# define png_debug1(l,m,p1) \
+ do { \
+ int num_tabs=l; \
+ char format[256]; \
+ snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
+ (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
+ m,PNG_STRING_NEWLINE); \
+ fprintf(PNG_DEBUG_FILE,format,p1); \
+ } while (0)
+# endif
+# ifndef png_debug2
+# define png_debug2(l,m,p1,p2) \
+ do { \
+ int num_tabs=l; \
+ char format[256]; \
+ snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
+ (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
+ m,PNG_STRING_NEWLINE); \
+ fprintf(PNG_DEBUG_FILE,format,p1,p2); \
+ } while (0)
+# endif
+# endif /* __STDC __ */
+# endif /* (PNG_DEBUG > 1) */
+
+# endif /* _MSC_VER */
+# endif /* (PNG_DEBUG > 0) */
+#endif /* PNG_DEBUG */
+#ifndef png_debug
+# define png_debug(l, m) ((void)0)
+#endif
+#ifndef png_debug1
+# define png_debug1(l, m, p1) ((void)0)
+#endif
+#ifndef png_debug2
+# define png_debug2(l, m, p1, p2) ((void)0)
+#endif
+#endif /* PNGDEBUG_H */
diff --git a/libs/imagequant/external/libpng/pngerror.c b/libs/imagequant/external/libpng/pngerror.c
new file mode 100644
index 00000000..01a7ef53
--- /dev/null
+++ b/libs/imagequant/external/libpng/pngerror.c
@@ -0,0 +1,971 @@
+/* pngerror.c - stub functions for i/o and memory allocation
+ *
+ * Copyright (c) 2018-2025 Cosmin Truta
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all error handling. Users who
+ * need special error handling are expected to write replacement functions
+ * and use png_set_error_fn() to use those functions. See the instructions
+ * at each function.
+ */
+
+#include "pngpriv.h"
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+
+static PNG_FUNCTION(void /* PRIVATE */,
+png_default_error,(png_const_structrp png_ptr, png_const_charp error_message),
+ PNG_NORETURN);
+
+#ifdef PNG_WARNINGS_SUPPORTED
+static void /* PRIVATE */
+png_default_warning(png_const_structrp png_ptr,
+ png_const_charp warning_message);
+#endif /* WARNINGS */
+
+/* This function is called whenever there is a fatal error. This function
+ * should not be changed. If there is a need to handle errors differently,
+ * you should supply a replacement error function and use png_set_error_fn()
+ * to replace the error function at run-time.
+ */
+#ifdef PNG_ERROR_TEXT_SUPPORTED
+PNG_FUNCTION(void,PNGAPI
+png_error,(png_const_structrp png_ptr, png_const_charp error_message),
+ PNG_NORETURN)
+{
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ char msg[16];
+ if (png_ptr != NULL)
+ {
+ if ((png_ptr->flags &
+ (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0)
+ {
+ if (*error_message == PNG_LITERAL_SHARP)
+ {
+ /* Strip "#nnnn " from beginning of error message. */
+ int offset;
+ for (offset = 1; offset<15; offset++)
+ if (error_message[offset] == ' ')
+ break;
+
+ if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)
+ {
+ int i;
+ for (i = 0; i < offset - 1; i++)
+ msg[i] = error_message[i + 1];
+ msg[i - 1] = '\0';
+ error_message = msg;
+ }
+
+ else
+ error_message += offset;
+ }
+
+ else
+ {
+ if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)
+ {
+ msg[0] = '0';
+ msg[1] = '\0';
+ error_message = msg;
+ }
+ }
+ }
+ }
+#endif
+ if (png_ptr != NULL && png_ptr->error_fn != NULL)
+ (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr),
+ error_message);
+
+ /* If the custom handler doesn't exist, or if it returns,
+ use the default handler, which will not return. */
+ png_default_error(png_ptr, error_message);
+}
+#else
+PNG_FUNCTION(void,PNGAPI
+png_err,(png_const_structrp png_ptr),PNG_NORETURN)
+{
+ /* Prior to 1.5.2 the error_fn received a NULL pointer, expressed
+ * erroneously as '\0', instead of the empty string "". This was
+ * apparently an error, introduced in libpng-1.2.20, and png_default_error
+ * will crash in this case.
+ */
+ if (png_ptr != NULL && png_ptr->error_fn != NULL)
+ (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), "");
+
+ /* If the custom handler doesn't exist, or if it returns,
+ use the default handler, which will not return. */
+ png_default_error(png_ptr, "");
+}
+#endif /* ERROR_TEXT */
+
+/* Utility to safely appends strings to a buffer. This never errors out so
+ * error checking is not required in the caller.
+ */
+size_t
+png_safecat(png_charp buffer, size_t bufsize, size_t pos,
+ png_const_charp string)
+{
+ if (buffer != NULL && pos < bufsize)
+ {
+ if (string != NULL)
+ while (*string != '\0' && pos < bufsize-1)
+ buffer[pos++] = *string++;
+
+ buffer[pos] = '\0';
+ }
+
+ return pos;
+}
+
+#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
+/* Utility to dump an unsigned value into a buffer, given a start pointer and
+ * and end pointer (which should point just *beyond* the end of the buffer!)
+ * Returns the pointer to the start of the formatted string.
+ */
+png_charp
+png_format_number(png_const_charp start, png_charp end, int format,
+ png_alloc_size_t number)
+{
+ int count = 0; /* number of digits output */
+ int mincount = 1; /* minimum number required */
+ int output = 0; /* digit output (for the fixed point format) */
+
+ *--end = '\0';
+
+ /* This is written so that the loop always runs at least once, even with
+ * number zero.
+ */
+ while (end > start && (number != 0 || count < mincount))
+ {
+
+ static const char digits[] = "0123456789ABCDEF";
+
+ switch (format)
+ {
+ case PNG_NUMBER_FORMAT_fixed:
+ /* Needs five digits (the fraction) */
+ mincount = 5;
+ if (output != 0 || number % 10 != 0)
+ {
+ *--end = digits[number % 10];
+ output = 1;
+ }
+ number /= 10;
+ break;
+
+ case PNG_NUMBER_FORMAT_02u:
+ /* Expects at least 2 digits. */
+ mincount = 2;
+ /* FALLTHROUGH */
+
+ case PNG_NUMBER_FORMAT_u:
+ *--end = digits[number % 10];
+ number /= 10;
+ break;
+
+ case PNG_NUMBER_FORMAT_02x:
+ /* This format expects at least two digits */
+ mincount = 2;
+ /* FALLTHROUGH */
+
+ case PNG_NUMBER_FORMAT_x:
+ *--end = digits[number & 0xf];
+ number >>= 4;
+ break;
+
+ default: /* an error */
+ number = 0;
+ break;
+ }
+
+ /* Keep track of the number of digits added */
+ ++count;
+
+ /* Float a fixed number here: */
+ if ((format == PNG_NUMBER_FORMAT_fixed) && (count == 5) && (end > start))
+ {
+ /* End of the fraction, but maybe nothing was output? In that case
+ * drop the decimal point. If the number is a true zero handle that
+ * here.
+ */
+ if (output != 0)
+ *--end = '.';
+ else if (number == 0) /* and !output */
+ *--end = '0';
+ }
+ }
+
+ return end;
+}
+#endif
+
+#ifdef PNG_WARNINGS_SUPPORTED
+/* This function is called whenever there is a non-fatal error. This function
+ * should not be changed. If there is a need to handle warnings differently,
+ * you should supply a replacement warning function and use
+ * png_set_error_fn() to replace the warning function at run-time.
+ */
+void PNGAPI
+png_warning(png_const_structrp png_ptr, png_const_charp warning_message)
+{
+ int offset = 0;
+ if (png_ptr != NULL)
+ {
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ if ((png_ptr->flags &
+ (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0)
+#endif
+ {
+ if (*warning_message == PNG_LITERAL_SHARP)
+ {
+ for (offset = 1; offset < 15; offset++)
+ if (warning_message[offset] == ' ')
+ break;
+ }
+ }
+ }
+ if (png_ptr != NULL && png_ptr->warning_fn != NULL)
+ (*(png_ptr->warning_fn))(png_constcast(png_structrp,png_ptr),
+ warning_message + offset);
+ else
+ png_default_warning(png_ptr, warning_message + offset);
+}
+
+/* These functions support 'formatted' warning messages with up to
+ * PNG_WARNING_PARAMETER_COUNT parameters. In the format string the parameter
+ * is introduced by @, where 'number' starts at 1. This follows the
+ * standard established by X/Open for internationalizable error messages.
+ */
+void
+png_warning_parameter(png_warning_parameters p, int number,
+ png_const_charp string)
+{
+ if (number > 0 && number <= PNG_WARNING_PARAMETER_COUNT)
+ (void)png_safecat(p[number-1], (sizeof p[number-1]), 0, string);
+}
+
+void
+png_warning_parameter_unsigned(png_warning_parameters p, int number, int format,
+ png_alloc_size_t value)
+{
+ char buffer[PNG_NUMBER_BUFFER_SIZE] = {0};
+ png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value));
+}
+
+void
+png_warning_parameter_signed(png_warning_parameters p, int number, int format,
+ png_int_32 value)
+{
+ png_alloc_size_t u;
+ png_charp str;
+ char buffer[PNG_NUMBER_BUFFER_SIZE] = {0};
+
+ /* Avoid overflow by doing the negate in a png_alloc_size_t: */
+ u = (png_alloc_size_t)value;
+ if (value < 0)
+ u = ~u + 1;
+
+ str = PNG_FORMAT_NUMBER(buffer, format, u);
+
+ if (value < 0 && str > buffer)
+ *--str = '-';
+
+ png_warning_parameter(p, number, str);
+}
+
+void
+png_formatted_warning(png_const_structrp png_ptr, png_warning_parameters p,
+ png_const_charp message)
+{
+ /* The internal buffer is just 192 bytes - enough for all our messages,
+ * overflow doesn't happen because this code checks! If someone figures
+ * out how to send us a message longer than 192 bytes, all that will
+ * happen is that the message will be truncated appropriately.
+ */
+ size_t i = 0; /* Index in the msg[] buffer: */
+ char msg[192];
+
+ /* Each iteration through the following loop writes at most one character
+ * to msg[i++] then returns here to validate that there is still space for
+ * the trailing '\0'. It may (in the case of a parameter) read more than
+ * one character from message[]; it must check for '\0' and continue to the
+ * test if it finds the end of string.
+ */
+ while (i<(sizeof msg)-1 && *message != '\0')
+ {
+ /* '@' at end of string is now just printed (previously it was skipped);
+ * it is an error in the calling code to terminate the string with @.
+ */
+ if (p != NULL && *message == '@' && message[1] != '\0')
+ {
+ int parameter_char = *++message; /* Consume the '@' */
+ static const char valid_parameters[] = "123456789";
+ int parameter = 0;
+
+ /* Search for the parameter digit, the index in the string is the
+ * parameter to use.
+ */
+ while (valid_parameters[parameter] != parameter_char &&
+ valid_parameters[parameter] != '\0')
+ ++parameter;
+
+ /* If the parameter digit is out of range it will just get printed. */
+ if (parameter < PNG_WARNING_PARAMETER_COUNT)
+ {
+ /* Append this parameter */
+ png_const_charp parm = p[parameter];
+ png_const_charp pend = p[parameter] + (sizeof p[parameter]);
+
+ /* No need to copy the trailing '\0' here, but there is no guarantee
+ * that parm[] has been initialized, so there is no guarantee of a
+ * trailing '\0':
+ */
+ while (i<(sizeof msg)-1 && *parm != '\0' && parm < pend)
+ msg[i++] = *parm++;
+
+ /* Consume the parameter digit too: */
+ ++message;
+ continue;
+ }
+
+ /* else not a parameter and there is a character after the @ sign; just
+ * copy that. This is known not to be '\0' because of the test above.
+ */
+ }
+
+ /* At this point *message can't be '\0', even in the bad parameter case
+ * above where there is a lone '@' at the end of the message string.
+ */
+ msg[i++] = *message++;
+ }
+
+ /* i is always less than (sizeof msg), so: */
+ msg[i] = '\0';
+
+ /* And this is the formatted message. It may be larger than
+ * PNG_MAX_ERROR_TEXT, but that is only used for 'chunk' errors and these
+ * are not (currently) formatted.
+ */
+ png_warning(png_ptr, msg);
+}
+#endif /* WARNINGS */
+
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+void PNGAPI
+png_benign_error(png_const_structrp png_ptr, png_const_charp error_message)
+{
+ if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0)
+ {
+# ifdef PNG_READ_SUPPORTED
+ if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
+ png_ptr->chunk_name != 0)
+ png_chunk_warning(png_ptr, error_message);
+ else
+# endif
+ png_warning(png_ptr, error_message);
+ }
+
+ else
+ {
+# ifdef PNG_READ_SUPPORTED
+ if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
+ png_ptr->chunk_name != 0)
+ png_chunk_error(png_ptr, error_message);
+ else
+# endif
+ png_error(png_ptr, error_message);
+ }
+
+# ifndef PNG_ERROR_TEXT_SUPPORTED
+ PNG_UNUSED(error_message)
+# endif
+}
+
+void /* PRIVATE */
+png_app_warning(png_const_structrp png_ptr, png_const_charp error_message)
+{
+ if ((png_ptr->flags & PNG_FLAG_APP_WARNINGS_WARN) != 0)
+ png_warning(png_ptr, error_message);
+ else
+ png_error(png_ptr, error_message);
+
+# ifndef PNG_ERROR_TEXT_SUPPORTED
+ PNG_UNUSED(error_message)
+# endif
+}
+
+void /* PRIVATE */
+png_app_error(png_const_structrp png_ptr, png_const_charp error_message)
+{
+ if ((png_ptr->flags & PNG_FLAG_APP_ERRORS_WARN) != 0)
+ png_warning(png_ptr, error_message);
+ else
+ png_error(png_ptr, error_message);
+
+# ifndef PNG_ERROR_TEXT_SUPPORTED
+ PNG_UNUSED(error_message)
+# endif
+}
+#endif /* BENIGN_ERRORS */
+
+#define PNG_MAX_ERROR_TEXT 196 /* Currently limited by profile_error in png.c */
+#if defined(PNG_WARNINGS_SUPPORTED) || \
+ (defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED))
+/* These utilities are used internally to build an error message that relates
+ * to the current chunk. The chunk name comes from png_ptr->chunk_name,
+ * which is used to prefix the message. The message is limited in length
+ * to 63 bytes. The name characters are output as hex digits wrapped in []
+ * if the character is invalid.
+ */
+#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
+static const char png_digit[16] = {
+ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
+ 'A', 'B', 'C', 'D', 'E', 'F'
+};
+
+static void /* PRIVATE */
+png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp
+ error_message)
+{
+ png_uint_32 chunk_name = png_ptr->chunk_name;
+ int iout = 0, ishift = 24;
+
+ while (ishift >= 0)
+ {
+ int c = (int)(chunk_name >> ishift) & 0xff;
+
+ ishift -= 8;
+ if (isnonalpha(c) != 0)
+ {
+ buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET;
+ buffer[iout++] = png_digit[(c & 0xf0) >> 4];
+ buffer[iout++] = png_digit[c & 0x0f];
+ buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET;
+ }
+
+ else
+ {
+ buffer[iout++] = (char)c;
+ }
+ }
+
+ if (error_message == NULL)
+ buffer[iout] = '\0';
+
+ else
+ {
+ int iin = 0;
+
+ buffer[iout++] = ':';
+ buffer[iout++] = ' ';
+
+ while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0')
+ buffer[iout++] = error_message[iin++];
+
+ /* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */
+ buffer[iout] = '\0';
+ }
+}
+#endif /* WARNINGS || ERROR_TEXT */
+
+#if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
+PNG_FUNCTION(void,PNGAPI
+png_chunk_error,(png_const_structrp png_ptr, png_const_charp error_message),
+ PNG_NORETURN)
+{
+ char msg[18+PNG_MAX_ERROR_TEXT];
+ if (png_ptr == NULL)
+ png_error(png_ptr, error_message);
+
+ else
+ {
+ png_format_buffer(png_ptr, msg, error_message);
+ png_error(png_ptr, msg);
+ }
+}
+#endif /* READ && ERROR_TEXT */
+
+#ifdef PNG_WARNINGS_SUPPORTED
+void PNGAPI
+png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message)
+{
+ char msg[18+PNG_MAX_ERROR_TEXT];
+ if (png_ptr == NULL)
+ png_warning(png_ptr, warning_message);
+
+ else
+ {
+ png_format_buffer(png_ptr, msg, warning_message);
+ png_warning(png_ptr, msg);
+ }
+}
+#endif /* WARNINGS */
+
+#ifdef PNG_READ_SUPPORTED
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+void PNGAPI
+png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp
+ error_message)
+{
+ if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0)
+ png_chunk_warning(png_ptr, error_message);
+
+ else
+ png_chunk_error(png_ptr, error_message);
+
+# ifndef PNG_ERROR_TEXT_SUPPORTED
+ PNG_UNUSED(error_message)
+# endif
+}
+#endif
+#endif /* READ */
+
+void /* PRIVATE */
+png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error)
+{
+# ifndef PNG_WARNINGS_SUPPORTED
+ PNG_UNUSED(message)
+# endif
+
+ /* This is always supported, but for just read or just write it
+ * unconditionally does the right thing.
+ */
+# if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
+ if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
+# endif
+
+# ifdef PNG_READ_SUPPORTED
+ {
+ if (error < PNG_CHUNK_ERROR)
+ png_chunk_warning(png_ptr, message);
+
+ else
+ png_chunk_benign_error(png_ptr, message);
+ }
+# endif
+
+# if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
+ else if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
+# endif
+
+# ifdef PNG_WRITE_SUPPORTED
+ {
+ if (error < PNG_CHUNK_WRITE_ERROR)
+ png_app_warning(png_ptr, message);
+
+ else
+ png_app_error(png_ptr, message);
+ }
+# endif
+}
+
+#ifdef PNG_ERROR_TEXT_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_FUNCTION(void,
+png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN)
+{
+# define fixed_message "fixed point overflow in "
+# define fixed_message_ln ((sizeof fixed_message)-1)
+ unsigned int iin;
+ char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT];
+ memcpy(msg, fixed_message, fixed_message_ln);
+ iin = 0;
+ if (name != NULL)
+ while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0)
+ {
+ msg[fixed_message_ln + iin] = name[iin];
+ ++iin;
+ }
+ msg[fixed_message_ln + iin] = 0;
+ png_error(png_ptr, msg);
+}
+#endif
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+/* This API only exists if ANSI-C style error handling is used,
+ * otherwise it is necessary for png_default_error to be overridden.
+ */
+jmp_buf* PNGAPI
+png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn,
+ size_t jmp_buf_size)
+{
+ /* From libpng 1.6.0 the app gets one chance to set a 'jmpbuf_size' value
+ * and it must not change after that. Libpng doesn't care how big the
+ * buffer is, just that it doesn't change.
+ *
+ * If the buffer size is no *larger* than the size of jmp_buf when libpng is
+ * compiled a built in jmp_buf is returned; this preserves the pre-1.6.0
+ * semantics that this call will not fail. If the size is larger, however,
+ * the buffer is allocated and this may fail, causing the function to return
+ * NULL.
+ */
+ if (png_ptr == NULL)
+ return NULL;
+
+ if (png_ptr->jmp_buf_ptr == NULL)
+ {
+ png_ptr->jmp_buf_size = 0; /* not allocated */
+
+ if (jmp_buf_size <= (sizeof png_ptr->jmp_buf_local))
+ png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local;
+
+ else
+ {
+ png_ptr->jmp_buf_ptr = png_voidcast(jmp_buf *,
+ png_malloc_warn(png_ptr, jmp_buf_size));
+
+ if (png_ptr->jmp_buf_ptr == NULL)
+ return NULL; /* new NULL return on OOM */
+
+ png_ptr->jmp_buf_size = jmp_buf_size;
+ }
+ }
+
+ else /* Already allocated: check the size */
+ {
+ size_t size = png_ptr->jmp_buf_size;
+
+ if (size == 0)
+ {
+ size = (sizeof png_ptr->jmp_buf_local);
+ if (png_ptr->jmp_buf_ptr != &png_ptr->jmp_buf_local)
+ {
+ /* This is an internal error in libpng: somehow we have been left
+ * with a stack allocated jmp_buf when the application regained
+ * control. It's always possible to fix this up, but for the moment
+ * this is a png_error because that makes it easy to detect.
+ */
+ png_error(png_ptr, "Libpng jmp_buf still allocated");
+ /* png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; */
+ }
+ }
+
+ if (size != jmp_buf_size)
+ {
+ png_warning(png_ptr, "Application jmp_buf size changed");
+ return NULL; /* caller will probably crash: no choice here */
+ }
+ }
+
+ /* Finally fill in the function, now we have a satisfactory buffer. It is
+ * valid to change the function on every call.
+ */
+ png_ptr->longjmp_fn = longjmp_fn;
+ return png_ptr->jmp_buf_ptr;
+}
+
+void /* PRIVATE */
+png_free_jmpbuf(png_structrp png_ptr)
+{
+ if (png_ptr != NULL)
+ {
+ jmp_buf *jb = png_ptr->jmp_buf_ptr;
+
+ /* A size of 0 is used to indicate a local, stack, allocation of the
+ * pointer; used here and in png.c
+ */
+ if (jb != NULL && png_ptr->jmp_buf_size > 0)
+ {
+
+ /* This stuff is so that a failure to free the error control structure
+ * does not leave libpng in a state with no valid error handling: the
+ * free always succeeds, if there is an error it gets ignored.
+ */
+ if (jb != &png_ptr->jmp_buf_local)
+ {
+ /* Make an internal, libpng, jmp_buf to return here */
+ jmp_buf free_jmp_buf;
+
+ if (!setjmp(free_jmp_buf))
+ {
+ png_ptr->jmp_buf_ptr = &free_jmp_buf; /* come back here */
+ png_ptr->jmp_buf_size = 0; /* stack allocation */
+ png_ptr->longjmp_fn = longjmp;
+ png_free(png_ptr, jb); /* Return to setjmp on error */
+ }
+ }
+ }
+
+ /* *Always* cancel everything out: */
+ png_ptr->jmp_buf_size = 0;
+ png_ptr->jmp_buf_ptr = NULL;
+ png_ptr->longjmp_fn = 0;
+ }
+}
+#endif
+
+/* This is the default error handling function. Note that replacements for
+ * this function MUST NOT RETURN, or the program will likely crash. This
+ * function is used by default, or if the program supplies NULL for the
+ * error function pointer in png_set_error_fn().
+ */
+static PNG_FUNCTION(void /* PRIVATE */,
+png_default_error,(png_const_structrp png_ptr, png_const_charp error_message),
+ PNG_NORETURN)
+{
+#ifdef PNG_CONSOLE_IO_SUPPORTED
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ /* Check on NULL only added in 1.5.4 */
+ if (error_message != NULL && *error_message == PNG_LITERAL_SHARP)
+ {
+ /* Strip "#nnnn " from beginning of error message. */
+ int offset;
+ char error_number[16];
+ for (offset = 0; offset<15; offset++)
+ {
+ error_number[offset] = error_message[offset + 1];
+ if (error_message[offset] == ' ')
+ break;
+ }
+
+ if ((offset > 1) && (offset < 15))
+ {
+ error_number[offset - 1] = '\0';
+ fprintf(stderr, "libpng error no. %s: %s",
+ error_number, error_message + offset + 1);
+ fprintf(stderr, PNG_STRING_NEWLINE);
+ }
+
+ else
+ {
+ fprintf(stderr, "libpng error: %s, offset=%d",
+ error_message, offset);
+ fprintf(stderr, PNG_STRING_NEWLINE);
+ }
+ }
+ else
+#endif
+ {
+ fprintf(stderr, "libpng error: %s", error_message ? error_message :
+ "undefined");
+ fprintf(stderr, PNG_STRING_NEWLINE);
+ }
+#else
+ PNG_UNUSED(error_message) /* Make compiler happy */
+#endif
+ png_longjmp(png_ptr, 1);
+}
+
+PNG_FUNCTION(void,PNGAPI
+png_longjmp,(png_const_structrp png_ptr, int val),PNG_NORETURN)
+{
+#ifdef PNG_SETJMP_SUPPORTED
+ if (png_ptr != NULL && png_ptr->longjmp_fn != NULL &&
+ png_ptr->jmp_buf_ptr != NULL)
+ png_ptr->longjmp_fn(*png_ptr->jmp_buf_ptr, val);
+#else
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(val)
+#endif
+
+ /* If control reaches this point, png_longjmp() must not return. The only
+ * choice is to terminate the whole process (or maybe the thread); to do
+ * this the ANSI-C abort() function is used unless a different method is
+ * implemented by overriding the default configuration setting for
+ * PNG_ABORT().
+ */
+ PNG_ABORT();
+}
+
+#ifdef PNG_WARNINGS_SUPPORTED
+/* This function is called when there is a warning, but the library thinks
+ * it can continue anyway. Replacement functions don't have to do anything
+ * here if you don't want them to. In the default configuration, png_ptr is
+ * not used, but it is passed in case it may be useful.
+ */
+static void /* PRIVATE */
+png_default_warning(png_const_structrp png_ptr, png_const_charp warning_message)
+{
+#ifdef PNG_CONSOLE_IO_SUPPORTED
+# ifdef PNG_ERROR_NUMBERS_SUPPORTED
+ if (*warning_message == PNG_LITERAL_SHARP)
+ {
+ int offset;
+ char warning_number[16];
+ for (offset = 0; offset < 15; offset++)
+ {
+ warning_number[offset] = warning_message[offset + 1];
+ if (warning_message[offset] == ' ')
+ break;
+ }
+
+ if ((offset > 1) && (offset < 15))
+ {
+ warning_number[offset + 1] = '\0';
+ fprintf(stderr, "libpng warning no. %s: %s",
+ warning_number, warning_message + offset);
+ fprintf(stderr, PNG_STRING_NEWLINE);
+ }
+
+ else
+ {
+ fprintf(stderr, "libpng warning: %s",
+ warning_message);
+ fprintf(stderr, PNG_STRING_NEWLINE);
+ }
+ }
+ else
+# endif
+
+ {
+ fprintf(stderr, "libpng warning: %s", warning_message);
+ fprintf(stderr, PNG_STRING_NEWLINE);
+ }
+#else
+ PNG_UNUSED(warning_message) /* Make compiler happy */
+#endif
+ PNG_UNUSED(png_ptr) /* Make compiler happy */
+}
+#endif /* WARNINGS */
+
+/* This function is called when the application wants to use another method
+ * of handling errors and warnings. Note that the error function MUST NOT
+ * return to the calling routine or serious problems will occur. The return
+ * method used in the default routine calls longjmp(png_ptr->jmp_buf_ptr, 1)
+ */
+void PNGAPI
+png_set_error_fn(png_structrp png_ptr, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warning_fn)
+{
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->error_ptr = error_ptr;
+ png_ptr->error_fn = error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
+ png_ptr->warning_fn = warning_fn;
+#else
+ PNG_UNUSED(warning_fn)
+#endif
+}
+
+
+/* This function returns a pointer to the error_ptr associated with the user
+ * functions. The application should free any memory associated with this
+ * pointer before png_write_destroy and png_read_destroy are called.
+ */
+png_voidp PNGAPI
+png_get_error_ptr(png_const_structrp png_ptr)
+{
+ if (png_ptr == NULL)
+ return NULL;
+
+ return (png_voidp)png_ptr->error_ptr;
+}
+
+
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+void PNGAPI
+png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode)
+{
+ if (png_ptr != NULL)
+ {
+ png_ptr->flags &=
+ ((~(PNG_FLAG_STRIP_ERROR_NUMBERS |
+ PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
+ }
+}
+#endif
+
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
+ defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+ /* Currently the above both depend on SETJMP_SUPPORTED, however it would be
+ * possible to implement without setjmp support just so long as there is some
+ * way to handle the error return here:
+ */
+PNG_FUNCTION(void /* PRIVATE */, (PNGCBAPI
+png_safe_error),(png_structp png_nonconst_ptr, png_const_charp error_message),
+ PNG_NORETURN)
+{
+ png_const_structrp png_ptr = png_nonconst_ptr;
+ png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
+
+ /* An error is always logged here, overwriting anything (typically a warning)
+ * that is already there:
+ */
+ if (image != NULL)
+ {
+ png_safecat(image->message, (sizeof image->message), 0, error_message);
+ image->warning_or_error |= PNG_IMAGE_ERROR;
+
+ /* Retrieve the jmp_buf from within the png_control, making this work for
+ * C++ compilation too is pretty tricky: C++ wants a pointer to the first
+ * element of a jmp_buf, but C doesn't tell us the type of that.
+ */
+ if (image->opaque != NULL && image->opaque->error_buf != NULL)
+ longjmp(png_control_jmp_buf(image->opaque), 1);
+
+ /* Missing longjmp buffer, the following is to help debugging: */
+ {
+ size_t pos = png_safecat(image->message, (sizeof image->message), 0,
+ "bad longjmp: ");
+ png_safecat(image->message, (sizeof image->message), pos,
+ error_message);
+ }
+ }
+
+ /* Here on an internal programming error. */
+ abort();
+}
+
+#ifdef PNG_WARNINGS_SUPPORTED
+void /* PRIVATE */ PNGCBAPI
+png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message)
+{
+ png_const_structrp png_ptr = png_nonconst_ptr;
+ png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
+
+ /* A warning is only logged if there is no prior warning or error. */
+ if (image->warning_or_error == 0)
+ {
+ png_safecat(image->message, (sizeof image->message), 0, warning_message);
+ image->warning_or_error |= PNG_IMAGE_WARNING;
+ }
+}
+#endif
+
+int /* PRIVATE */
+png_safe_execute(png_imagep image, int (*function)(png_voidp), png_voidp arg)
+{
+ const png_voidp saved_error_buf = image->opaque->error_buf;
+ jmp_buf safe_jmpbuf;
+
+ /* Safely execute function(arg), with png_error returning back here. */
+ if (setjmp(safe_jmpbuf) == 0)
+ {
+ int result;
+
+ image->opaque->error_buf = safe_jmpbuf;
+ result = function(arg);
+ image->opaque->error_buf = saved_error_buf;
+
+ if (result)
+ return 1; /* success */
+ }
+
+ /* The function failed either because of a caught png_error and a regular
+ * return of false above or because of an uncaught png_error from the
+ * function itself. Ensure that the error_buf is always set back to the
+ * value saved above:
+ */
+ image->opaque->error_buf = saved_error_buf;
+
+ /* On the final false return, when about to return control to the caller, the
+ * image is freed (png_image_free does this check but it is duplicated here
+ * for clarity:
+ */
+ if (saved_error_buf == NULL)
+ png_image_free(image);
+
+ return 0; /* failure */
+}
+#endif /* SIMPLIFIED READ || SIMPLIFIED_WRITE */
+#endif /* READ || WRITE */
diff --git a/libs/imagequant/external/libpng/pngget.c b/libs/imagequant/external/libpng/pngget.c
new file mode 100644
index 00000000..1ebb1144
--- /dev/null
+++ b/libs/imagequant/external/libpng/pngget.c
@@ -0,0 +1,1370 @@
+/* pngget.c - retrieval of values from info struct
+ *
+ * Copyright (c) 2018-2025 Cosmin Truta
+ * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ */
+
+#include "pngpriv.h"
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+
+png_uint_32 PNGAPI
+png_get_valid(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_uint_32 flag)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ {
+#ifdef PNG_READ_tRNS_SUPPORTED
+ /* png_handle_PLTE() may have canceled a valid tRNS chunk but left the
+ * 'valid' flag for the detection of duplicate chunks. Do not report a
+ * valid tRNS chunk in this case.
+ */
+ if (flag == PNG_INFO_tRNS && png_ptr->num_trans == 0)
+ return 0;
+#endif
+
+ return info_ptr->valid & flag;
+ }
+
+ return 0;
+}
+
+size_t PNGAPI
+png_get_rowbytes(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->rowbytes;
+
+ return 0;
+}
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+png_bytepp PNGAPI
+png_get_rows(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->row_pointers;
+
+ return 0;
+}
+#endif
+
+#ifdef PNG_EASY_ACCESS_SUPPORTED
+/* Easy access to info, added in libpng-0.99 */
+png_uint_32 PNGAPI
+png_get_image_width(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->width;
+
+ return 0;
+}
+
+png_uint_32 PNGAPI
+png_get_image_height(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->height;
+
+ return 0;
+}
+
+png_byte PNGAPI
+png_get_bit_depth(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->bit_depth;
+
+ return 0;
+}
+
+png_byte PNGAPI
+png_get_color_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->color_type;
+
+ return 0;
+}
+
+png_byte PNGAPI
+png_get_filter_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->filter_type;
+
+ return 0;
+}
+
+png_byte PNGAPI
+png_get_interlace_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->interlace_type;
+
+ return 0;
+}
+
+png_byte PNGAPI
+png_get_compression_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->compression_type;
+
+ return 0;
+}
+
+png_uint_32 PNGAPI
+png_get_x_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
+ info_ptr)
+{
+#ifdef PNG_pHYs_SUPPORTED
+ png_debug(1, "in png_get_x_pixels_per_meter");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_pHYs) != 0)
+ {
+ if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER)
+ return info_ptr->x_pixels_per_unit;
+ }
+#else
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(info_ptr)
+#endif
+
+ return 0;
+}
+
+png_uint_32 PNGAPI
+png_get_y_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
+ info_ptr)
+{
+#ifdef PNG_pHYs_SUPPORTED
+ png_debug(1, "in png_get_y_pixels_per_meter");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_pHYs) != 0)
+ {
+ if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER)
+ return info_ptr->y_pixels_per_unit;
+ }
+#else
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(info_ptr)
+#endif
+
+ return 0;
+}
+
+png_uint_32 PNGAPI
+png_get_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+#ifdef PNG_pHYs_SUPPORTED
+ png_debug(1, "in png_get_pixels_per_meter");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_pHYs) != 0)
+ {
+ if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER &&
+ info_ptr->x_pixels_per_unit == info_ptr->y_pixels_per_unit)
+ return info_ptr->x_pixels_per_unit;
+ }
+#else
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(info_ptr)
+#endif
+
+ return 0;
+}
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+float PNGAPI
+png_get_pixel_aspect_ratio(png_const_structrp png_ptr, png_const_inforp
+ info_ptr)
+{
+#ifdef PNG_READ_pHYs_SUPPORTED
+ png_debug(1, "in png_get_pixel_aspect_ratio");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_pHYs) != 0)
+ {
+ if (info_ptr->x_pixels_per_unit != 0)
+ return (float)info_ptr->y_pixels_per_unit
+ / (float)info_ptr->x_pixels_per_unit;
+ }
+#else
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(info_ptr)
+#endif
+
+ return (float)0.0;
+}
+#endif
+
+#ifdef PNG_FIXED_POINT_SUPPORTED
+png_fixed_point PNGAPI
+png_get_pixel_aspect_ratio_fixed(png_const_structrp png_ptr,
+ png_const_inforp info_ptr)
+{
+#ifdef PNG_READ_pHYs_SUPPORTED
+ png_debug(1, "in png_get_pixel_aspect_ratio_fixed");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_pHYs) != 0 &&
+ info_ptr->x_pixels_per_unit > 0 && info_ptr->y_pixels_per_unit > 0 &&
+ info_ptr->x_pixels_per_unit <= PNG_UINT_31_MAX &&
+ info_ptr->y_pixels_per_unit <= PNG_UINT_31_MAX)
+ {
+ png_fixed_point res;
+
+ /* The following casts work because a PNG 4 byte integer only has a valid
+ * range of 0..2^31-1; otherwise the cast might overflow.
+ */
+ if (png_muldiv(&res, (png_int_32)info_ptr->y_pixels_per_unit, PNG_FP_1,
+ (png_int_32)info_ptr->x_pixels_per_unit) != 0)
+ return res;
+ }
+#else
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(info_ptr)
+#endif
+
+ return 0;
+}
+#endif
+
+png_int_32 PNGAPI
+png_get_x_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+#ifdef PNG_oFFs_SUPPORTED
+ png_debug(1, "in png_get_x_offset_microns");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_oFFs) != 0)
+ {
+ if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER)
+ return info_ptr->x_offset;
+ }
+#else
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(info_ptr)
+#endif
+
+ return 0;
+}
+
+png_int_32 PNGAPI
+png_get_y_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+#ifdef PNG_oFFs_SUPPORTED
+ png_debug(1, "in png_get_y_offset_microns");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_oFFs) != 0)
+ {
+ if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER)
+ return info_ptr->y_offset;
+ }
+#else
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(info_ptr)
+#endif
+
+ return 0;
+}
+
+png_int_32 PNGAPI
+png_get_x_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+#ifdef PNG_oFFs_SUPPORTED
+ png_debug(1, "in png_get_x_offset_pixels");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_oFFs) != 0)
+ {
+ if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL)
+ return info_ptr->x_offset;
+ }
+#else
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(info_ptr)
+#endif
+
+ return 0;
+}
+
+png_int_32 PNGAPI
+png_get_y_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+#ifdef PNG_oFFs_SUPPORTED
+ png_debug(1, "in png_get_y_offset_pixels");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_oFFs) != 0)
+ {
+ if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL)
+ return info_ptr->y_offset;
+ }
+#else
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(info_ptr)
+#endif
+
+ return 0;
+}
+
+#ifdef PNG_INCH_CONVERSIONS_SUPPORTED
+static png_uint_32
+ppi_from_ppm(png_uint_32 ppm)
+{
+#if 0
+ /* The conversion is *(2.54/100), in binary (32 digits):
+ * .00000110100000001001110101001001
+ */
+ png_uint_32 t1001, t1101;
+ ppm >>= 1; /* .1 */
+ t1001 = ppm + (ppm >> 3); /* .1001 */
+ t1101 = t1001 + (ppm >> 1); /* .1101 */
+ ppm >>= 20; /* .000000000000000000001 */
+ t1101 += t1101 >> 15; /* .1101000000000001101 */
+ t1001 >>= 11; /* .000000000001001 */
+ t1001 += t1001 >> 12; /* .000000000001001000000001001 */
+ ppm += t1001; /* .000000000001001000001001001 */
+ ppm += t1101; /* .110100000001001110101001001 */
+ return (ppm + 16) >> 5;/* .00000110100000001001110101001001 */
+#else
+ /* The argument is a PNG unsigned integer, so it is not permitted
+ * to be bigger than 2^31.
+ */
+ png_fixed_point result;
+ if (ppm <= PNG_UINT_31_MAX && png_muldiv(&result, (png_int_32)ppm, 127,
+ 5000) != 0)
+ return (png_uint_32)result;
+
+ /* Overflow. */
+ return 0;
+#endif
+}
+
+png_uint_32 PNGAPI
+png_get_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ return ppi_from_ppm(png_get_pixels_per_meter(png_ptr, info_ptr));
+}
+
+png_uint_32 PNGAPI
+png_get_x_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ return ppi_from_ppm(png_get_x_pixels_per_meter(png_ptr, info_ptr));
+}
+
+png_uint_32 PNGAPI
+png_get_y_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ return ppi_from_ppm(png_get_y_pixels_per_meter(png_ptr, info_ptr));
+}
+
+#ifdef PNG_FIXED_POINT_SUPPORTED
+static png_fixed_point
+png_fixed_inches_from_microns(png_const_structrp png_ptr, png_int_32 microns)
+{
+ /* Convert from meters * 1,000,000 to inches * 100,000, meters to
+ * inches is simply *(100/2.54), so we want *(10/2.54) == 500/127.
+ * Notice that this can overflow - a warning is output and 0 is
+ * returned.
+ */
+ png_fixed_point result;
+
+ if (png_muldiv(&result, microns, 500, 127) != 0)
+ return result;
+
+ png_warning(png_ptr, "fixed point overflow ignored");
+ return 0;
+}
+
+png_fixed_point PNGAPI
+png_get_x_offset_inches_fixed(png_const_structrp png_ptr,
+ png_const_inforp info_ptr)
+{
+ return png_fixed_inches_from_microns(png_ptr,
+ png_get_x_offset_microns(png_ptr, info_ptr));
+}
+#endif /* FIXED_POINT */
+
+#ifdef PNG_FIXED_POINT_SUPPORTED
+png_fixed_point PNGAPI
+png_get_y_offset_inches_fixed(png_const_structrp png_ptr,
+ png_const_inforp info_ptr)
+{
+ return png_fixed_inches_from_microns(png_ptr,
+ png_get_y_offset_microns(png_ptr, info_ptr));
+}
+#endif
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+float PNGAPI
+png_get_x_offset_inches(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ /* To avoid the overflow do the conversion directly in floating
+ * point.
+ */
+ return (float)(png_get_x_offset_microns(png_ptr, info_ptr) * .00003937);
+}
+#endif
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+float PNGAPI
+png_get_y_offset_inches(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ /* To avoid the overflow do the conversion directly in floating
+ * point.
+ */
+ return (float)(png_get_y_offset_microns(png_ptr, info_ptr) * .00003937);
+}
+#endif
+
+#ifdef PNG_pHYs_SUPPORTED
+png_uint_32 PNGAPI
+png_get_pHYs_dpi(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
+{
+ png_uint_32 retval = 0;
+
+ png_debug1(1, "in %s retrieval function", "pHYs");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_pHYs) != 0)
+ {
+ if (res_x != NULL)
+ {
+ *res_x = info_ptr->x_pixels_per_unit;
+ retval |= PNG_INFO_pHYs;
+ }
+
+ if (res_y != NULL)
+ {
+ *res_y = info_ptr->y_pixels_per_unit;
+ retval |= PNG_INFO_pHYs;
+ }
+
+ if (unit_type != NULL)
+ {
+ *unit_type = (int)info_ptr->phys_unit_type;
+ retval |= PNG_INFO_pHYs;
+
+ if (*unit_type == 1)
+ {
+ if (res_x != NULL) *res_x = (png_uint_32)(*res_x * .0254 + .50);
+ if (res_y != NULL) *res_y = (png_uint_32)(*res_y * .0254 + .50);
+ }
+ }
+ }
+
+ return retval;
+}
+#endif /* pHYs */
+#endif /* INCH_CONVERSIONS */
+
+/* png_get_channels really belongs in here, too, but it's been around longer */
+
+#endif /* EASY_ACCESS */
+
+
+png_byte PNGAPI
+png_get_channels(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->channels;
+
+ return 0;
+}
+
+#ifdef PNG_READ_SUPPORTED
+png_const_bytep PNGAPI
+png_get_signature(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return info_ptr->signature;
+
+ return NULL;
+}
+#endif
+
+#ifdef PNG_bKGD_SUPPORTED
+png_uint_32 PNGAPI
+png_get_bKGD(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_color_16p *background)
+{
+ png_debug1(1, "in %s retrieval function", "bKGD");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_bKGD) != 0 &&
+ background != NULL)
+ {
+ *background = &(info_ptr->background);
+ return PNG_INFO_bKGD;
+ }
+
+ return 0;
+}
+#endif
+
+#ifdef PNG_cHRM_SUPPORTED
+/* The XYZ APIs were added in 1.5.5 to take advantage of the code added at the
+ * same time to correct the rgb grayscale coefficient defaults obtained from the
+ * cHRM chunk in 1.5.4
+ */
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_cHRM(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ double *whitex, double *whitey, double *redx, double *redy,
+ double *greenx, double *greeny, double *bluex, double *bluey)
+{
+ png_debug1(1, "in %s retrieval function", "cHRM");
+
+ /* PNGv3: this just returns the values store from the cHRM, if any. */
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_cHRM) != 0)
+ {
+ if (whitex != NULL)
+ *whitex = png_float(png_ptr, info_ptr->cHRM.whitex, "cHRM wx");
+ if (whitey != NULL)
+ *whitey = png_float(png_ptr, info_ptr->cHRM.whitey, "cHRM wy");
+ if (redx != NULL)
+ *redx = png_float(png_ptr, info_ptr->cHRM.redx, "cHRM rx");
+ if (redy != NULL)
+ *redy = png_float(png_ptr, info_ptr->cHRM.redy, "cHRM ry");
+ if (greenx != NULL)
+ *greenx = png_float(png_ptr, info_ptr->cHRM.greenx, "cHRM gx");
+ if (greeny != NULL)
+ *greeny = png_float(png_ptr, info_ptr->cHRM.greeny, "cHRM gy");
+ if (bluex != NULL)
+ *bluex = png_float(png_ptr, info_ptr->cHRM.bluex, "cHRM bx");
+ if (bluey != NULL)
+ *bluey = png_float(png_ptr, info_ptr->cHRM.bluey, "cHRM by");
+ return PNG_INFO_cHRM;
+ }
+
+ return 0;
+}
+
+png_uint_32 PNGAPI
+png_get_cHRM_XYZ(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ double *red_X, double *red_Y, double *red_Z, double *green_X,
+ double *green_Y, double *green_Z, double *blue_X, double *blue_Y,
+ double *blue_Z)
+{
+ png_XYZ XYZ;
+ png_debug1(1, "in %s retrieval function", "cHRM_XYZ(float)");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_cHRM) != 0 &&
+ png_XYZ_from_xy(&XYZ, &info_ptr->cHRM) == 0)
+ {
+ if (red_X != NULL)
+ *red_X = png_float(png_ptr, XYZ.red_X, "cHRM red X");
+ if (red_Y != NULL)
+ *red_Y = png_float(png_ptr, XYZ.red_Y, "cHRM red Y");
+ if (red_Z != NULL)
+ *red_Z = png_float(png_ptr, XYZ.red_Z, "cHRM red Z");
+ if (green_X != NULL)
+ *green_X = png_float(png_ptr, XYZ.green_X, "cHRM green X");
+ if (green_Y != NULL)
+ *green_Y = png_float(png_ptr, XYZ.green_Y, "cHRM green Y");
+ if (green_Z != NULL)
+ *green_Z = png_float(png_ptr, XYZ.green_Z, "cHRM green Z");
+ if (blue_X != NULL)
+ *blue_X = png_float(png_ptr, XYZ.blue_X, "cHRM blue X");
+ if (blue_Y != NULL)
+ *blue_Y = png_float(png_ptr, XYZ.blue_Y, "cHRM blue Y");
+ if (blue_Z != NULL)
+ *blue_Z = png_float(png_ptr, XYZ.blue_Z, "cHRM blue Z");
+ return PNG_INFO_cHRM;
+ }
+
+ return 0;
+}
+# endif
+
+# ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
+ png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
+ png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
+ png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
+ png_fixed_point *int_blue_Z)
+{
+ png_XYZ XYZ;
+ png_debug1(1, "in %s retrieval function", "cHRM_XYZ");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_cHRM) != 0U &&
+ png_XYZ_from_xy(&XYZ, &info_ptr->cHRM) == 0)
+ {
+ if (int_red_X != NULL) *int_red_X = XYZ.red_X;
+ if (int_red_Y != NULL) *int_red_Y = XYZ.red_Y;
+ if (int_red_Z != NULL) *int_red_Z = XYZ.red_Z;
+ if (int_green_X != NULL) *int_green_X = XYZ.green_X;
+ if (int_green_Y != NULL) *int_green_Y = XYZ.green_Y;
+ if (int_green_Z != NULL) *int_green_Z = XYZ.green_Z;
+ if (int_blue_X != NULL) *int_blue_X = XYZ.blue_X;
+ if (int_blue_Y != NULL) *int_blue_Y = XYZ.blue_Y;
+ if (int_blue_Z != NULL) *int_blue_Z = XYZ.blue_Z;
+ return PNG_INFO_cHRM;
+ }
+
+ return 0;
+}
+
+png_uint_32 PNGAPI
+png_get_cHRM_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_fixed_point *whitex, png_fixed_point *whitey, png_fixed_point *redx,
+ png_fixed_point *redy, png_fixed_point *greenx, png_fixed_point *greeny,
+ png_fixed_point *bluex, png_fixed_point *bluey)
+{
+ png_debug1(1, "in %s retrieval function", "cHRM");
+
+ /* PNGv3: this just returns the values store from the cHRM, if any. */
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_cHRM) != 0)
+ {
+ if (whitex != NULL) *whitex = info_ptr->cHRM.whitex;
+ if (whitey != NULL) *whitey = info_ptr->cHRM.whitey;
+ if (redx != NULL) *redx = info_ptr->cHRM.redx;
+ if (redy != NULL) *redy = info_ptr->cHRM.redy;
+ if (greenx != NULL) *greenx = info_ptr->cHRM.greenx;
+ if (greeny != NULL) *greeny = info_ptr->cHRM.greeny;
+ if (bluex != NULL) *bluex = info_ptr->cHRM.bluex;
+ if (bluey != NULL) *bluey = info_ptr->cHRM.bluey;
+ return PNG_INFO_cHRM;
+ }
+
+ return 0;
+}
+# endif
+#endif
+
+#ifdef PNG_gAMA_SUPPORTED
+# ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_gAMA_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_fixed_point *file_gamma)
+{
+ png_debug1(1, "in %s retrieval function", "gAMA");
+
+ /* PNGv3 compatibility: only report gAMA if it is really present. */
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_gAMA) != 0)
+ {
+ if (file_gamma != NULL) *file_gamma = info_ptr->gamma;
+ return PNG_INFO_gAMA;
+ }
+
+ return 0;
+}
+# endif
+
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_gAMA(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ double *file_gamma)
+{
+ png_debug1(1, "in %s retrieval function", "gAMA(float)");
+
+ /* PNGv3 compatibility: only report gAMA if it is really present. */
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_gAMA) != 0)
+ {
+ if (file_gamma != NULL)
+ *file_gamma = png_float(png_ptr, info_ptr->gamma, "gAMA");
+
+ return PNG_INFO_gAMA;
+ }
+
+ return 0;
+}
+# endif
+#endif
+
+#ifdef PNG_sRGB_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sRGB(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ int *file_srgb_intent)
+{
+ png_debug1(1, "in %s retrieval function", "sRGB");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_sRGB) != 0)
+ {
+ if (file_srgb_intent != NULL)
+ *file_srgb_intent = info_ptr->rendering_intent;
+ return PNG_INFO_sRGB;
+ }
+
+ return 0;
+}
+#endif
+
+#ifdef PNG_iCCP_SUPPORTED
+png_uint_32 PNGAPI
+png_get_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_charpp name, int *compression_type,
+ png_bytepp profile, png_uint_32 *proflen)
+{
+ png_debug1(1, "in %s retrieval function", "iCCP");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_iCCP) != 0 &&
+ name != NULL && profile != NULL && proflen != NULL)
+ {
+ *name = info_ptr->iccp_name;
+ *profile = info_ptr->iccp_profile;
+ *proflen = png_get_uint_32(info_ptr->iccp_profile);
+ /* This is somewhat irrelevant since the profile data returned has
+ * actually been uncompressed.
+ */
+ if (compression_type != NULL)
+ *compression_type = PNG_COMPRESSION_TYPE_BASE;
+ return PNG_INFO_iCCP;
+ }
+
+ return 0;
+
+}
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+int PNGAPI
+png_get_sPLT(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_sPLT_tpp spalettes)
+{
+ png_debug1(1, "in %s retrieval function", "sPLT");
+
+ if (png_ptr != NULL && info_ptr != NULL && spalettes != NULL)
+ {
+ *spalettes = info_ptr->splt_palettes;
+ return info_ptr->splt_palettes_num;
+ }
+
+ return 0;
+}
+#endif
+
+#ifdef PNG_cICP_SUPPORTED
+png_uint_32 PNGAPI
+png_get_cICP(png_const_structrp png_ptr,
+ png_const_inforp info_ptr, png_bytep colour_primaries,
+ png_bytep transfer_function, png_bytep matrix_coefficients,
+ png_bytep video_full_range_flag)
+{
+ png_debug1(1, "in %s retrieval function", "cICP");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_cICP) != 0 &&
+ colour_primaries != NULL && transfer_function != NULL &&
+ matrix_coefficients != NULL && video_full_range_flag != NULL)
+ {
+ *colour_primaries = info_ptr->cicp_colour_primaries;
+ *transfer_function = info_ptr->cicp_transfer_function;
+ *matrix_coefficients = info_ptr->cicp_matrix_coefficients;
+ *video_full_range_flag = info_ptr->cicp_video_full_range_flag;
+ return (PNG_INFO_cICP);
+ }
+
+ return 0;
+}
+#endif
+
+#ifdef PNG_cLLI_SUPPORTED
+# ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_cLLI_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_uint_32p maxCLL,
+ png_uint_32p maxFALL)
+{
+ png_debug1(1, "in %s retrieval function", "cLLI");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_cLLI) != 0)
+ {
+ if (maxCLL != NULL) *maxCLL = info_ptr->maxCLL;
+ if (maxFALL != NULL) *maxFALL = info_ptr->maxFALL;
+ return PNG_INFO_cLLI;
+ }
+
+ return 0;
+}
+# endif
+
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_cLLI(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ double *maxCLL, double *maxFALL)
+{
+ png_debug1(1, "in %s retrieval function", "cLLI(float)");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_cLLI) != 0)
+ {
+ if (maxCLL != NULL) *maxCLL = info_ptr->maxCLL * .0001;
+ if (maxFALL != NULL) *maxFALL = info_ptr->maxFALL * .0001;
+ return PNG_INFO_cLLI;
+ }
+
+ return 0;
+}
+# endif
+#endif /* cLLI */
+
+#ifdef PNG_mDCV_SUPPORTED
+# ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_mDCV_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_fixed_point *white_x, png_fixed_point *white_y,
+ png_fixed_point *red_x, png_fixed_point *red_y,
+ png_fixed_point *green_x, png_fixed_point *green_y,
+ png_fixed_point *blue_x, png_fixed_point *blue_y,
+ png_uint_32p mastering_maxDL, png_uint_32p mastering_minDL)
+{
+ png_debug1(1, "in %s retrieval function", "mDCV");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_mDCV) != 0)
+ {
+ if (white_x != NULL) *white_x = info_ptr->mastering_white_x * 2;
+ if (white_y != NULL) *white_y = info_ptr->mastering_white_y * 2;
+ if (red_x != NULL) *red_x = info_ptr->mastering_red_x * 2;
+ if (red_y != NULL) *red_y = info_ptr->mastering_red_y * 2;
+ if (green_x != NULL) *green_x = info_ptr->mastering_green_x * 2;
+ if (green_y != NULL) *green_y = info_ptr->mastering_green_y * 2;
+ if (blue_x != NULL) *blue_x = info_ptr->mastering_blue_x * 2;
+ if (blue_y != NULL) *blue_y = info_ptr->mastering_blue_y * 2;
+ if (mastering_maxDL != NULL) *mastering_maxDL = info_ptr->mastering_maxDL;
+ if (mastering_minDL != NULL) *mastering_minDL = info_ptr->mastering_minDL;
+ return PNG_INFO_mDCV;
+ }
+
+ return 0;
+}
+# endif
+
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_mDCV(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ double *white_x, double *white_y, double *red_x, double *red_y,
+ double *green_x, double *green_y, double *blue_x, double *blue_y,
+ double *mastering_maxDL, double *mastering_minDL)
+{
+ png_debug1(1, "in %s retrieval function", "mDCV(float)");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_mDCV) != 0)
+ {
+ if (white_x != NULL) *white_x = info_ptr->mastering_white_x * .00002;
+ if (white_y != NULL) *white_y = info_ptr->mastering_white_y * .00002;
+ if (red_x != NULL) *red_x = info_ptr->mastering_red_x * .00002;
+ if (red_y != NULL) *red_y = info_ptr->mastering_red_y * .00002;
+ if (green_x != NULL) *green_x = info_ptr->mastering_green_x * .00002;
+ if (green_y != NULL) *green_y = info_ptr->mastering_green_y * .00002;
+ if (blue_x != NULL) *blue_x = info_ptr->mastering_blue_x * .00002;
+ if (blue_y != NULL) *blue_y = info_ptr->mastering_blue_y * .00002;
+ if (mastering_maxDL != NULL)
+ *mastering_maxDL = info_ptr->mastering_maxDL * .0001;
+ if (mastering_minDL != NULL)
+ *mastering_minDL = info_ptr->mastering_minDL * .0001;
+ return PNG_INFO_mDCV;
+ }
+
+ return 0;
+}
+# endif /* FLOATING_POINT */
+#endif /* mDCV */
+
+#ifdef PNG_eXIf_SUPPORTED
+png_uint_32 PNGAPI
+png_get_eXIf(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_bytep *exif)
+{
+ png_warning(png_ptr, "png_get_eXIf does not work; use png_get_eXIf_1");
+ PNG_UNUSED(info_ptr)
+ PNG_UNUSED(exif)
+ return 0;
+}
+
+png_uint_32 PNGAPI
+png_get_eXIf_1(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_uint_32 *num_exif, png_bytep *exif)
+{
+ png_debug1(1, "in %s retrieval function", "eXIf");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_eXIf) != 0 && exif != NULL)
+ {
+ *num_exif = info_ptr->num_exif;
+ *exif = info_ptr->exif;
+ return PNG_INFO_eXIf;
+ }
+
+ return 0;
+}
+#endif
+
+#ifdef PNG_hIST_SUPPORTED
+png_uint_32 PNGAPI
+png_get_hIST(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_uint_16p *hist)
+{
+ png_debug1(1, "in %s retrieval function", "hIST");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_hIST) != 0 && hist != NULL)
+ {
+ *hist = info_ptr->hist;
+ return PNG_INFO_hIST;
+ }
+
+ return 0;
+}
+#endif
+
+png_uint_32 PNGAPI
+png_get_IHDR(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_uint_32 *width, png_uint_32 *height, int *bit_depth,
+ int *color_type, int *interlace_type, int *compression_type,
+ int *filter_type)
+{
+ png_debug1(1, "in %s retrieval function", "IHDR");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return 0;
+
+ if (width != NULL)
+ *width = info_ptr->width;
+
+ if (height != NULL)
+ *height = info_ptr->height;
+
+ if (bit_depth != NULL)
+ *bit_depth = info_ptr->bit_depth;
+
+ if (color_type != NULL)
+ *color_type = info_ptr->color_type;
+
+ if (compression_type != NULL)
+ *compression_type = info_ptr->compression_type;
+
+ if (filter_type != NULL)
+ *filter_type = info_ptr->filter_type;
+
+ if (interlace_type != NULL)
+ *interlace_type = info_ptr->interlace_type;
+
+ /* This is redundant if we can be sure that the info_ptr values were all
+ * assigned in png_set_IHDR(). We do the check anyhow in case an
+ * application has ignored our advice not to mess with the members
+ * of info_ptr directly.
+ */
+ png_check_IHDR(png_ptr, info_ptr->width, info_ptr->height,
+ info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type,
+ info_ptr->compression_type, info_ptr->filter_type);
+
+ return 1;
+}
+
+#ifdef PNG_oFFs_SUPPORTED
+png_uint_32 PNGAPI
+png_get_oFFs(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type)
+{
+ png_debug1(1, "in %s retrieval function", "oFFs");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_oFFs) != 0 &&
+ offset_x != NULL && offset_y != NULL && unit_type != NULL)
+ {
+ *offset_x = info_ptr->x_offset;
+ *offset_y = info_ptr->y_offset;
+ *unit_type = (int)info_ptr->offset_unit_type;
+ return PNG_INFO_oFFs;
+ }
+
+ return 0;
+}
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+png_uint_32 PNGAPI
+png_get_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams,
+ png_charp *units, png_charpp *params)
+{
+ png_debug1(1, "in %s retrieval function", "pCAL");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_pCAL) != 0 &&
+ purpose != NULL && X0 != NULL && X1 != NULL && type != NULL &&
+ nparams != NULL && units != NULL && params != NULL)
+ {
+ *purpose = info_ptr->pcal_purpose;
+ *X0 = info_ptr->pcal_X0;
+ *X1 = info_ptr->pcal_X1;
+ *type = (int)info_ptr->pcal_type;
+ *nparams = (int)info_ptr->pcal_nparams;
+ *units = info_ptr->pcal_units;
+ *params = info_ptr->pcal_params;
+ return PNG_INFO_pCAL;
+ }
+
+ return 0;
+}
+#endif
+
+#ifdef PNG_sCAL_SUPPORTED
+# ifdef PNG_FIXED_POINT_SUPPORTED
+# if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
+ defined(PNG_FLOATING_POINT_SUPPORTED)
+png_uint_32 PNGAPI
+png_get_sCAL_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ int *unit, png_fixed_point *width, png_fixed_point *height)
+{
+ png_debug1(1, "in %s retrieval function", "sCAL");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_sCAL) != 0)
+ {
+ *unit = info_ptr->scal_unit;
+ /*TODO: make this work without FP support; the API is currently eliminated
+ * if neither floating point APIs nor internal floating point arithmetic
+ * are enabled.
+ */
+ *width = png_fixed(png_ptr, atof(info_ptr->scal_s_width), "sCAL width");
+ *height = png_fixed(png_ptr, atof(info_ptr->scal_s_height),
+ "sCAL height");
+ return PNG_INFO_sCAL;
+ }
+
+ return 0;
+}
+# endif /* FLOATING_ARITHMETIC */
+# endif /* FIXED_POINT */
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sCAL(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ int *unit, double *width, double *height)
+{
+ png_debug1(1, "in %s retrieval function", "sCAL(float)");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_sCAL) != 0)
+ {
+ *unit = info_ptr->scal_unit;
+ *width = atof(info_ptr->scal_s_width);
+ *height = atof(info_ptr->scal_s_height);
+ return PNG_INFO_sCAL;
+ }
+
+ return 0;
+}
+# endif /* FLOATING POINT */
+png_uint_32 PNGAPI
+png_get_sCAL_s(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ int *unit, png_charpp width, png_charpp height)
+{
+ png_debug1(1, "in %s retrieval function", "sCAL(str)");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_sCAL) != 0)
+ {
+ *unit = info_ptr->scal_unit;
+ *width = info_ptr->scal_s_width;
+ *height = info_ptr->scal_s_height;
+ return PNG_INFO_sCAL;
+ }
+
+ return 0;
+}
+#endif /* sCAL */
+
+#ifdef PNG_pHYs_SUPPORTED
+png_uint_32 PNGAPI
+png_get_pHYs(png_const_structrp png_ptr, png_const_inforp info_ptr,
+ png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
+{
+ png_uint_32 retval = 0;
+
+ png_debug1(1, "in %s retrieval function", "pHYs");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_pHYs) != 0)
+ {
+ if (res_x != NULL)
+ {
+ *res_x = info_ptr->x_pixels_per_unit;
+ retval |= PNG_INFO_pHYs;
+ }
+
+ if (res_y != NULL)
+ {
+ *res_y = info_ptr->y_pixels_per_unit;
+ retval |= PNG_INFO_pHYs;
+ }
+
+ if (unit_type != NULL)
+ {
+ *unit_type = (int)info_ptr->phys_unit_type;
+ retval |= PNG_INFO_pHYs;
+ }
+ }
+
+ return retval;
+}
+#endif /* pHYs */
+
+png_uint_32 PNGAPI
+png_get_PLTE(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_colorp *palette, int *num_palette)
+{
+ png_debug1(1, "in %s retrieval function", "PLTE");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_PLTE) != 0 && palette != NULL)
+ {
+ *palette = info_ptr->palette;
+ *num_palette = info_ptr->num_palette;
+ png_debug1(3, "num_palette = %d", *num_palette);
+ return PNG_INFO_PLTE;
+ }
+
+ return 0;
+}
+
+#ifdef PNG_sBIT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sBIT(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_color_8p *sig_bit)
+{
+ png_debug1(1, "in %s retrieval function", "sBIT");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_sBIT) != 0 && sig_bit != NULL)
+ {
+ *sig_bit = &(info_ptr->sig_bit);
+ return PNG_INFO_sBIT;
+ }
+
+ return 0;
+}
+#endif
+
+#ifdef PNG_TEXT_SUPPORTED
+int PNGAPI
+png_get_text(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_textp *text_ptr, int *num_text)
+{
+ if (png_ptr != NULL && info_ptr != NULL && info_ptr->num_text > 0)
+ {
+ png_debug1(1, "in text retrieval function, chunk typeid = 0x%lx",
+ (unsigned long)png_ptr->chunk_name);
+
+ if (text_ptr != NULL)
+ *text_ptr = info_ptr->text;
+
+ if (num_text != NULL)
+ *num_text = info_ptr->num_text;
+
+ return info_ptr->num_text;
+ }
+
+ if (num_text != NULL)
+ *num_text = 0;
+
+ return 0;
+}
+#endif
+
+#ifdef PNG_tIME_SUPPORTED
+png_uint_32 PNGAPI
+png_get_tIME(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_timep *mod_time)
+{
+ png_debug1(1, "in %s retrieval function", "tIME");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_tIME) != 0 && mod_time != NULL)
+ {
+ *mod_time = &(info_ptr->mod_time);
+ return PNG_INFO_tIME;
+ }
+
+ return 0;
+}
+#endif
+
+#ifdef PNG_tRNS_SUPPORTED
+png_uint_32 PNGAPI
+png_get_tRNS(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color)
+{
+ png_uint_32 retval = 0;
+
+ png_debug1(1, "in %s retrieval function", "tRNS");
+
+ if (png_ptr != NULL && info_ptr != NULL &&
+ (info_ptr->valid & PNG_INFO_tRNS) != 0)
+ {
+ if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (trans_alpha != NULL)
+ {
+ *trans_alpha = info_ptr->trans_alpha;
+ retval |= PNG_INFO_tRNS;
+ }
+
+ if (trans_color != NULL)
+ *trans_color = &(info_ptr->trans_color);
+ }
+
+ else /* if (info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) */
+ {
+ if (trans_color != NULL)
+ {
+ *trans_color = &(info_ptr->trans_color);
+ retval |= PNG_INFO_tRNS;
+ }
+
+ if (trans_alpha != NULL)
+ *trans_alpha = NULL;
+ }
+
+ if (num_trans != NULL)
+ {
+ *num_trans = info_ptr->num_trans;
+ retval |= PNG_INFO_tRNS;
+ }
+ }
+
+ return retval;
+}
+#endif
+
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+int PNGAPI
+png_get_unknown_chunks(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_unknown_chunkpp unknowns)
+{
+ if (png_ptr != NULL && info_ptr != NULL && unknowns != NULL)
+ {
+ *unknowns = info_ptr->unknown_chunks;
+ return info_ptr->unknown_chunks_num;
+ }
+
+ return 0;
+}
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+png_byte PNGAPI
+png_get_rgb_to_gray_status(png_const_structrp png_ptr)
+{
+ return (png_byte)(png_ptr ? png_ptr->rgb_to_gray_status : 0);
+}
+#endif
+
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+png_voidp PNGAPI
+png_get_user_chunk_ptr(png_const_structrp png_ptr)
+{
+ return (png_ptr ? png_ptr->user_chunk_ptr : NULL);
+}
+#endif
+
+size_t PNGAPI
+png_get_compression_buffer_size(png_const_structrp png_ptr)
+{
+ if (png_ptr == NULL)
+ return 0;
+
+#ifdef PNG_WRITE_SUPPORTED
+ if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
+#endif
+ {
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+ return png_ptr->IDAT_read_size;
+#else
+ return PNG_IDAT_READ_SIZE;
+#endif
+ }
+
+#ifdef PNG_WRITE_SUPPORTED
+ else
+ return png_ptr->zbuffer_size;
+#endif
+}
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+/* These functions were added to libpng 1.2.6 and were enabled
+ * by default in libpng-1.4.0 */
+png_uint_32 PNGAPI
+png_get_user_width_max(png_const_structrp png_ptr)
+{
+ return (png_ptr ? png_ptr->user_width_max : 0);
+}
+
+png_uint_32 PNGAPI
+png_get_user_height_max(png_const_structrp png_ptr)
+{
+ return (png_ptr ? png_ptr->user_height_max : 0);
+}
+
+/* This function was added to libpng 1.4.0 */
+png_uint_32 PNGAPI
+png_get_chunk_cache_max(png_const_structrp png_ptr)
+{
+ return (png_ptr ? png_ptr->user_chunk_cache_max : 0);
+}
+
+/* This function was added to libpng 1.4.1 */
+png_alloc_size_t PNGAPI
+png_get_chunk_malloc_max(png_const_structrp png_ptr)
+{
+ return (png_ptr ? png_ptr->user_chunk_malloc_max : 0);
+}
+#endif /* SET_USER_LIMITS */
+
+/* These functions were added to libpng 1.4.0 */
+#ifdef PNG_IO_STATE_SUPPORTED
+png_uint_32 PNGAPI
+png_get_io_state(png_const_structrp png_ptr)
+{
+ return png_ptr->io_state;
+}
+
+png_uint_32 PNGAPI
+png_get_io_chunk_type(png_const_structrp png_ptr)
+{
+ return png_ptr->chunk_name;
+}
+#endif /* IO_STATE */
+
+#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+# ifdef PNG_GET_PALETTE_MAX_SUPPORTED
+int PNGAPI
+png_get_palette_max(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ return png_ptr->num_palette_max;
+
+ return -1;
+}
+# endif
+#endif
+
+#endif /* READ || WRITE */
diff --git a/libs/imagequant/external/libpng/pnginfo.h b/libs/imagequant/external/libpng/pnginfo.h
new file mode 100644
index 00000000..584a42f9
--- /dev/null
+++ b/libs/imagequant/external/libpng/pnginfo.h
@@ -0,0 +1,263 @@
+/* pnginfo.h - internal structures for libpng
+ *
+ * Copyright (c) 2018-2025 Cosmin Truta
+ * Copyright (c) 1998-2002,2004,2006-2013,2018 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#ifndef PNGPRIV_H
+# error This file must not be included by applications; please include
+#endif
+
+/* INTERNAL, PRIVATE definition of a PNG.
+ *
+ * png_info is a modifiable description of a PNG datastream. The fields inside
+ * this structure are accessed through png_get_() functions and modified
+ * using png_set_() functions.
+ *
+ * Some functions in libpng do directly access members of png_info. However,
+ * this should be avoided. png_struct objects contain members which hold
+ * caches, sometimes optimised, of the values from png_info objects, and
+ * png_info is not passed to the functions which read and write image data.
+ */
+#ifndef PNGINFO_H
+#define PNGINFO_H
+
+struct png_info_def
+{
+ /* The following are necessary for every PNG file */
+ png_uint_32 width; /* width of image in pixels (from IHDR) */
+ png_uint_32 height; /* height of image in pixels (from IHDR) */
+ png_uint_32 valid; /* valid chunk data (see PNG_INFO_ below) */
+ size_t rowbytes; /* bytes needed to hold an untransformed row */
+ png_colorp palette; /* array of color values (valid & PNG_INFO_PLTE) */
+ png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */
+ png_uint_16 num_trans; /* number of transparent palette color (tRNS) */
+ png_byte bit_depth; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
+ png_byte color_type; /* see PNG_COLOR_TYPE_ below (from IHDR) */
+ /* The following three should have been named *_method not *_type */
+ png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
+ png_byte filter_type; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
+ png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
+
+ /* The following are set by png_set_IHDR, called from the application on
+ * write, but the are never actually used by the write code.
+ */
+ png_byte channels; /* number of data channels per pixel (1, 2, 3, 4) */
+ png_byte pixel_depth; /* number of bits per pixel */
+ png_byte spare_byte; /* to align the data, and for future use */
+
+#ifdef PNG_READ_SUPPORTED
+ /* This is never set during write */
+ png_byte signature[8]; /* magic bytes read by libpng from start of file */
+#endif
+
+ /* The rest of the data is optional. If you are reading, check the
+ * valid field to see if the information in these are valid. If you
+ * are writing, set the valid field to those chunks you want written,
+ * and initialize the appropriate fields below.
+ */
+
+#ifdef PNG_cICP_SUPPORTED
+ /* cICP chunk data */
+ png_byte cicp_colour_primaries;
+ png_byte cicp_transfer_function;
+ png_byte cicp_matrix_coefficients;
+ png_byte cicp_video_full_range_flag;
+#endif
+
+#ifdef PNG_iCCP_SUPPORTED
+ /* iCCP chunk data. */
+ png_charp iccp_name; /* profile name */
+ png_bytep iccp_profile; /* International Color Consortium profile data */
+ png_uint_32 iccp_proflen; /* ICC profile data length */
+#endif
+
+#ifdef PNG_cLLI_SUPPORTED
+ png_uint_32 maxCLL; /* cd/m2 (nits) * 10,000 */
+ png_uint_32 maxFALL;
+#endif
+
+#ifdef PNG_mDCV_SUPPORTED
+ png_uint_16 mastering_red_x; /* CIE (xy) x * 50,000 */
+ png_uint_16 mastering_red_y;
+ png_uint_16 mastering_green_x;
+ png_uint_16 mastering_green_y;
+ png_uint_16 mastering_blue_x;
+ png_uint_16 mastering_blue_y;
+ png_uint_16 mastering_white_x;
+ png_uint_16 mastering_white_y;
+ png_uint_32 mastering_maxDL; /* cd/m2 (nits) * 10,000 */
+ png_uint_32 mastering_minDL;
+#endif
+
+#ifdef PNG_TEXT_SUPPORTED
+ /* The tEXt, and zTXt chunks contain human-readable textual data in
+ * uncompressed, compressed, and optionally compressed forms, respectively.
+ * The data in "text" is an array of pointers to uncompressed,
+ * null-terminated C strings. Each chunk has a keyword that describes the
+ * textual data contained in that chunk. Keywords are not required to be
+ * unique, and the text string may be empty. Any number of text chunks may
+ * be in an image.
+ */
+ int num_text; /* number of comments read or comments to write */
+ int max_text; /* current size of text array */
+ png_textp text; /* array of comments read or comments to write */
+#endif /* TEXT */
+
+#ifdef PNG_tIME_SUPPORTED
+ /* The tIME chunk holds the last time the displayed image data was
+ * modified. See the png_time struct for the contents of this struct.
+ */
+ png_time mod_time;
+#endif
+
+#ifdef PNG_sBIT_SUPPORTED
+ /* The sBIT chunk specifies the number of significant high-order bits
+ * in the pixel data. Values are in the range [1, bit_depth], and are
+ * only specified for the channels in the pixel data. The contents of
+ * the low-order bits is not specified. Data is valid if
+ * (valid & PNG_INFO_sBIT) is non-zero.
+ */
+ png_color_8 sig_bit; /* significant bits in color channels */
+#endif
+
+#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
+defined(PNG_READ_BACKGROUND_SUPPORTED)
+ /* The tRNS chunk supplies transparency data for paletted images and
+ * other image types that don't need a full alpha channel. There are
+ * "num_trans" transparency values for a paletted image, stored in the
+ * same order as the palette colors, starting from index 0. Values
+ * for the data are in the range [0, 255], ranging from fully transparent
+ * to fully opaque, respectively. For non-paletted images, there is a
+ * single color specified that should be treated as fully transparent.
+ * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
+ */
+ png_bytep trans_alpha; /* alpha values for paletted image */
+ png_color_16 trans_color; /* transparent color for non-palette image */
+#endif
+
+#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ /* The bKGD chunk gives the suggested image background color if the
+ * display program does not have its own background color and the image
+ * is needs to composited onto a background before display. The colors
+ * in "background" are normally in the same color space/depth as the
+ * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
+ */
+ png_color_16 background;
+#endif
+
+#ifdef PNG_oFFs_SUPPORTED
+ /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
+ * and downwards from the top-left corner of the display, page, or other
+ * application-specific co-ordinate space. See the PNG_OFFSET_ defines
+ * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero.
+ */
+ png_int_32 x_offset; /* x offset on page */
+ png_int_32 y_offset; /* y offset on page */
+ png_byte offset_unit_type; /* offset units type */
+#endif
+
+#ifdef PNG_pHYs_SUPPORTED
+ /* The pHYs chunk gives the physical pixel density of the image for
+ * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
+ * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
+ */
+ png_uint_32 x_pixels_per_unit; /* horizontal pixel density */
+ png_uint_32 y_pixels_per_unit; /* vertical pixel density */
+ png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */
+#endif
+
+#ifdef PNG_eXIf_SUPPORTED
+ png_uint_32 num_exif; /* Added at libpng-1.6.31 */
+ png_bytep exif;
+#endif
+
+#ifdef PNG_hIST_SUPPORTED
+ /* The hIST chunk contains the relative frequency or importance of the
+ * various palette entries, so that a viewer can intelligently select a
+ * reduced-color palette, if required. Data is an array of "num_palette"
+ * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
+ * is non-zero.
+ */
+ png_uint_16p hist;
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+ /* The pCAL chunk describes a transformation between the stored pixel
+ * values and original physical data values used to create the image.
+ * The integer range [0, 2^bit_depth - 1] maps to the floating-point
+ * range given by [pcal_X0, pcal_X1], and are further transformed by a
+ * (possibly non-linear) transformation function given by "pcal_type"
+ * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_
+ * defines below, and the PNG-Group's PNG extensions document for a
+ * complete description of the transformations and how they should be
+ * implemented, and for a description of the ASCII parameter strings.
+ * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
+ */
+ png_charp pcal_purpose; /* pCAL chunk description string */
+ png_int_32 pcal_X0; /* minimum value */
+ png_int_32 pcal_X1; /* maximum value */
+ png_charp pcal_units; /* Latin-1 string giving physical units */
+ png_charpp pcal_params; /* ASCII strings containing parameter values */
+ png_byte pcal_type; /* equation type (see PNG_EQUATION_ below) */
+ png_byte pcal_nparams; /* number of parameters given in pcal_params */
+#endif
+
+/* New members added in libpng-1.0.6 */
+ png_uint_32 free_me; /* flags items libpng is responsible for freeing */
+
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+ /* Storage for unknown chunks that the library doesn't recognize. */
+ png_unknown_chunkp unknown_chunks;
+
+ /* The type of this field is limited by the type of
+ * png_struct::user_chunk_cache_max, else overflow can occur.
+ */
+ int unknown_chunks_num;
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+ /* Data on sPLT chunks (there may be more than one). */
+ png_sPLT_tp splt_palettes;
+ int splt_palettes_num; /* Match type returned by png_get API */
+#endif
+
+#ifdef PNG_sCAL_SUPPORTED
+ /* The sCAL chunk describes the actual physical dimensions of the
+ * subject matter of the graphic. The chunk contains a unit specification
+ * a byte value, and two ASCII strings representing floating-point
+ * values. The values are width and height corresponding to one pixel
+ * in the image. Data values are valid if (valid & PNG_INFO_sCAL) is
+ * non-zero.
+ */
+ png_byte scal_unit; /* unit of physical scale */
+ png_charp scal_s_width; /* string containing height */
+ png_charp scal_s_height; /* string containing width */
+#endif
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+ /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS)
+ non-zero */
+ /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
+ png_bytepp row_pointers; /* the image bits */
+#endif
+
+#ifdef PNG_cHRM_SUPPORTED
+ png_xy cHRM;
+#endif
+
+#ifdef PNG_gAMA_SUPPORTED
+ png_fixed_point gamma;
+#endif
+
+#ifdef PNG_sRGB_SUPPORTED
+ int rendering_intent;
+#endif
+};
+#endif /* PNGINFO_H */
diff --git a/libs/imagequant/external/libpng/pnglibconf.h b/libs/imagequant/external/libpng/pnglibconf.h
new file mode 100644
index 00000000..155d9921
--- /dev/null
+++ b/libs/imagequant/external/libpng/pnglibconf.h
@@ -0,0 +1,233 @@
+/* pnglibconf.h - library build configuration */
+
+/* libpng version 1.6.49.git */
+
+/* Copyright (c) 2018-2025 Cosmin Truta */
+/* Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson */
+
+/* This code is released under the libpng license. */
+/* For conditions of distribution and use, see the disclaimer */
+/* and license in png.h */
+
+/* pnglibconf.h */
+/* Machine generated file: DO NOT EDIT */
+/* Derived from: scripts/pnglibconf.dfa */
+#ifndef PNGLCONF_H
+#define PNGLCONF_H
+/* options */
+#define PNG_16BIT_SUPPORTED
+#define PNG_ALIGNED_MEMORY_SUPPORTED
+/*#undef PNG_ARM_NEON_API_SUPPORTED*/
+/*#undef PNG_ARM_NEON_CHECK_SUPPORTED*/
+#define PNG_BENIGN_ERRORS_SUPPORTED
+#define PNG_BENIGN_READ_ERRORS_SUPPORTED
+/*#undef PNG_BENIGN_WRITE_ERRORS_SUPPORTED*/
+#define PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
+#define PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+#define PNG_COLORSPACE_SUPPORTED
+#define PNG_CONSOLE_IO_SUPPORTED
+#define PNG_CONVERT_tIME_SUPPORTED
+/*#undef PNG_DISABLE_ADLER32_CHECK_SUPPORTED*/
+#define PNG_EASY_ACCESS_SUPPORTED
+/*#undef PNG_ERROR_NUMBERS_SUPPORTED*/
+#define PNG_ERROR_TEXT_SUPPORTED
+#define PNG_FIXED_POINT_SUPPORTED
+#define PNG_FLOATING_ARITHMETIC_SUPPORTED
+#define PNG_FLOATING_POINT_SUPPORTED
+#define PNG_FORMAT_AFIRST_SUPPORTED
+#define PNG_FORMAT_BGR_SUPPORTED
+#define PNG_GAMMA_SUPPORTED
+#define PNG_GET_PALETTE_MAX_SUPPORTED
+#define PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+#define PNG_INCH_CONVERSIONS_SUPPORTED
+#define PNG_INFO_IMAGE_SUPPORTED
+#define PNG_IO_STATE_SUPPORTED
+/*#undef PNG_MIPS_MMI_API_SUPPORTED*/
+/*#undef PNG_MIPS_MMI_CHECK_SUPPORTED*/
+/*#undef PNG_MIPS_MSA_API_SUPPORTED*/
+/*#undef PNG_MIPS_MSA_CHECK_SUPPORTED*/
+#define PNG_MNG_FEATURES_SUPPORTED
+#define PNG_POINTER_INDEXING_SUPPORTED
+/*#undef PNG_POWERPC_VSX_API_SUPPORTED*/
+/*#undef PNG_POWERPC_VSX_CHECK_SUPPORTED*/
+#define PNG_PROGRESSIVE_READ_SUPPORTED
+#define PNG_READ_16BIT_SUPPORTED
+#define PNG_READ_ALPHA_MODE_SUPPORTED
+#define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
+#define PNG_READ_BACKGROUND_SUPPORTED
+#define PNG_READ_BGR_SUPPORTED
+#define PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
+#define PNG_READ_COMPOSITE_NODIV_SUPPORTED
+#define PNG_READ_COMPRESSED_TEXT_SUPPORTED
+#define PNG_READ_EXPAND_16_SUPPORTED
+#define PNG_READ_EXPAND_SUPPORTED
+#define PNG_READ_FILLER_SUPPORTED
+#define PNG_READ_GAMMA_SUPPORTED
+#define PNG_READ_GET_PALETTE_MAX_SUPPORTED
+#define PNG_READ_GRAY_TO_RGB_SUPPORTED
+#define PNG_READ_INTERLACING_SUPPORTED
+#define PNG_READ_INT_FUNCTIONS_SUPPORTED
+#define PNG_READ_INVERT_ALPHA_SUPPORTED
+#define PNG_READ_INVERT_SUPPORTED
+#define PNG_READ_OPT_PLTE_SUPPORTED
+#define PNG_READ_PACKSWAP_SUPPORTED
+#define PNG_READ_PACK_SUPPORTED
+#define PNG_READ_QUANTIZE_SUPPORTED
+#define PNG_READ_RGB_TO_GRAY_SUPPORTED
+#define PNG_READ_SCALE_16_TO_8_SUPPORTED
+#define PNG_READ_SHIFT_SUPPORTED
+#define PNG_READ_STRIP_16_TO_8_SUPPORTED
+#define PNG_READ_STRIP_ALPHA_SUPPORTED
+#define PNG_READ_SUPPORTED
+#define PNG_READ_SWAP_ALPHA_SUPPORTED
+#define PNG_READ_SWAP_SUPPORTED
+#define PNG_READ_TEXT_SUPPORTED
+#define PNG_READ_TRANSFORMS_SUPPORTED
+#define PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_READ_USER_CHUNKS_SUPPORTED
+#define PNG_READ_USER_TRANSFORM_SUPPORTED
+#define PNG_READ_bKGD_SUPPORTED
+#define PNG_READ_cHRM_SUPPORTED
+#define PNG_READ_cICP_SUPPORTED
+#define PNG_READ_cLLI_SUPPORTED
+#define PNG_READ_eXIf_SUPPORTED
+#define PNG_READ_gAMA_SUPPORTED
+#define PNG_READ_hIST_SUPPORTED
+#define PNG_READ_iCCP_SUPPORTED
+#define PNG_READ_iTXt_SUPPORTED
+#define PNG_READ_mDCV_SUPPORTED
+#define PNG_READ_oFFs_SUPPORTED
+#define PNG_READ_pCAL_SUPPORTED
+#define PNG_READ_pHYs_SUPPORTED
+#define PNG_READ_sBIT_SUPPORTED
+#define PNG_READ_sCAL_SUPPORTED
+#define PNG_READ_sPLT_SUPPORTED
+#define PNG_READ_sRGB_SUPPORTED
+#define PNG_READ_tEXt_SUPPORTED
+#define PNG_READ_tIME_SUPPORTED
+#define PNG_READ_tRNS_SUPPORTED
+#define PNG_READ_zTXt_SUPPORTED
+#define PNG_SAVE_INT_32_SUPPORTED
+#define PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_SEQUENTIAL_READ_SUPPORTED
+#define PNG_SETJMP_SUPPORTED
+#define PNG_SET_OPTION_SUPPORTED
+#define PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_SET_USER_LIMITS_SUPPORTED
+#define PNG_SIMPLIFIED_READ_AFIRST_SUPPORTED
+#define PNG_SIMPLIFIED_READ_BGR_SUPPORTED
+#define PNG_SIMPLIFIED_READ_SUPPORTED
+#define PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
+#define PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED
+#define PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
+#define PNG_SIMPLIFIED_WRITE_SUPPORTED
+#define PNG_STDIO_SUPPORTED
+#define PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_TEXT_SUPPORTED
+#define PNG_TIME_RFC1123_SUPPORTED
+#define PNG_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_USER_CHUNKS_SUPPORTED
+#define PNG_USER_LIMITS_SUPPORTED
+#define PNG_USER_MEM_SUPPORTED
+#define PNG_USER_TRANSFORM_INFO_SUPPORTED
+#define PNG_USER_TRANSFORM_PTR_SUPPORTED
+#define PNG_WARNINGS_SUPPORTED
+#define PNG_WRITE_16BIT_SUPPORTED
+#define PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED
+#define PNG_WRITE_BGR_SUPPORTED
+#define PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
+#define PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+#define PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
+#define PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+#define PNG_WRITE_FILLER_SUPPORTED
+#define PNG_WRITE_FILTER_SUPPORTED
+#define PNG_WRITE_FLUSH_SUPPORTED
+#define PNG_WRITE_GET_PALETTE_MAX_SUPPORTED
+#define PNG_WRITE_INTERLACING_SUPPORTED
+#define PNG_WRITE_INT_FUNCTIONS_SUPPORTED
+#define PNG_WRITE_INVERT_ALPHA_SUPPORTED
+#define PNG_WRITE_INVERT_SUPPORTED
+#define PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+#define PNG_WRITE_PACKSWAP_SUPPORTED
+#define PNG_WRITE_PACK_SUPPORTED
+#define PNG_WRITE_SHIFT_SUPPORTED
+#define PNG_WRITE_SUPPORTED
+#define PNG_WRITE_SWAP_ALPHA_SUPPORTED
+#define PNG_WRITE_SWAP_SUPPORTED
+#define PNG_WRITE_TEXT_SUPPORTED
+#define PNG_WRITE_TRANSFORMS_SUPPORTED
+#define PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_WRITE_USER_TRANSFORM_SUPPORTED
+#define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+#define PNG_WRITE_bKGD_SUPPORTED
+#define PNG_WRITE_cHRM_SUPPORTED
+#define PNG_WRITE_cICP_SUPPORTED
+#define PNG_WRITE_cLLI_SUPPORTED
+#define PNG_WRITE_eXIf_SUPPORTED
+#define PNG_WRITE_gAMA_SUPPORTED
+#define PNG_WRITE_hIST_SUPPORTED
+#define PNG_WRITE_iCCP_SUPPORTED
+#define PNG_WRITE_iTXt_SUPPORTED
+#define PNG_WRITE_mDCV_SUPPORTED
+#define PNG_WRITE_oFFs_SUPPORTED
+#define PNG_WRITE_pCAL_SUPPORTED
+#define PNG_WRITE_pHYs_SUPPORTED
+#define PNG_WRITE_sBIT_SUPPORTED
+#define PNG_WRITE_sCAL_SUPPORTED
+#define PNG_WRITE_sPLT_SUPPORTED
+#define PNG_WRITE_sRGB_SUPPORTED
+#define PNG_WRITE_tEXt_SUPPORTED
+#define PNG_WRITE_tIME_SUPPORTED
+#define PNG_WRITE_tRNS_SUPPORTED
+#define PNG_WRITE_zTXt_SUPPORTED
+#define PNG_bKGD_SUPPORTED
+#define PNG_cHRM_SUPPORTED
+#define PNG_cICP_SUPPORTED
+#define PNG_cLLI_SUPPORTED
+#define PNG_eXIf_SUPPORTED
+#define PNG_gAMA_SUPPORTED
+#define PNG_hIST_SUPPORTED
+#define PNG_iCCP_SUPPORTED
+#define PNG_iTXt_SUPPORTED
+#define PNG_mDCV_SUPPORTED
+#define PNG_oFFs_SUPPORTED
+#define PNG_pCAL_SUPPORTED
+#define PNG_pHYs_SUPPORTED
+#define PNG_sBIT_SUPPORTED
+#define PNG_sCAL_SUPPORTED
+#define PNG_sPLT_SUPPORTED
+#define PNG_sRGB_SUPPORTED
+#define PNG_tEXt_SUPPORTED
+#define PNG_tIME_SUPPORTED
+#define PNG_tRNS_SUPPORTED
+#define PNG_zTXt_SUPPORTED
+/* end of options */
+/* settings */
+#define PNG_API_RULE 0
+#define PNG_DEFAULT_READ_MACROS 1
+#define PNG_GAMMA_THRESHOLD_FIXED 5000
+#define PNG_IDAT_READ_SIZE PNG_ZBUF_SIZE
+#define PNG_INFLATE_BUF_SIZE 1024
+#define PNG_LINKAGE_API extern
+#define PNG_LINKAGE_CALLBACK extern
+#define PNG_LINKAGE_DATA extern
+#define PNG_LINKAGE_FUNCTION extern
+#define PNG_MAX_GAMMA_8 11
+#define PNG_QUANTIZE_BLUE_BITS 5
+#define PNG_QUANTIZE_GREEN_BITS 5
+#define PNG_QUANTIZE_RED_BITS 5
+#define PNG_TEXT_Z_DEFAULT_COMPRESSION (-1)
+#define PNG_TEXT_Z_DEFAULT_STRATEGY 0
+#define PNG_USER_CHUNK_CACHE_MAX 1000
+#define PNG_USER_CHUNK_MALLOC_MAX 8000000
+#define PNG_USER_HEIGHT_MAX 1000000
+#define PNG_USER_WIDTH_MAX 1000000
+#define PNG_ZBUF_SIZE 8192
+#define PNG_ZLIB_VERNUM 0 /* unknown */
+#define PNG_Z_DEFAULT_COMPRESSION (-1)
+#define PNG_Z_DEFAULT_NOFILTER_STRATEGY 0
+#define PNG_Z_DEFAULT_STRATEGY 1
+#define PNG_sCAL_PRECISION 5
+#define PNG_sRGB_PROFILE_CHECKS 2
+/* end of settings */
+#endif /* PNGLCONF_H */
diff --git a/libs/imagequant/external/libpng/pngmem.c b/libs/imagequant/external/libpng/pngmem.c
new file mode 100644
index 00000000..71e61c99
--- /dev/null
+++ b/libs/imagequant/external/libpng/pngmem.c
@@ -0,0 +1,282 @@
+/* pngmem.c - stub functions for memory allocation
+ *
+ * Copyright (c) 2018-2025 Cosmin Truta
+ * Copyright (c) 1998-2002,2004,2006-2014,2016 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all memory allocation. Users who
+ * need special memory handling are expected to supply replacement
+ * functions for png_malloc() and png_free(), and to use
+ * png_create_read_struct_2() and png_create_write_struct_2() to
+ * identify the replacement functions.
+ */
+
+#include "pngpriv.h"
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+/* Free a png_struct */
+void /* PRIVATE */
+png_destroy_png_struct(png_structrp png_ptr)
+{
+ if (png_ptr != NULL)
+ {
+ /* png_free might call png_error and may certainly call
+ * png_get_mem_ptr, so fake a temporary png_struct to support this.
+ */
+ png_struct dummy_struct = *png_ptr;
+ memset(png_ptr, 0, (sizeof *png_ptr));
+ png_free(&dummy_struct, png_ptr);
+
+# ifdef PNG_SETJMP_SUPPORTED
+ /* We may have a jmp_buf left to deallocate. */
+ png_free_jmpbuf(&dummy_struct);
+# endif
+ }
+}
+
+/* Allocate memory. For reasonable files, size should never exceed
+ * 64K. However, zlib may allocate more than 64K if you don't tell
+ * it not to. See zconf.h and png.h for more information. zlib does
+ * need to allocate exactly 64K, so whatever you call here must
+ * have the ability to do that.
+ */
+PNG_FUNCTION(png_voidp,PNGAPI
+png_calloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
+{
+ png_voidp ret;
+
+ ret = png_malloc(png_ptr, size);
+
+ if (ret != NULL)
+ memset(ret, 0, size);
+
+ return ret;
+}
+
+/* png_malloc_base, an internal function added at libpng 1.6.0, does the work of
+ * allocating memory, taking into account limits and PNG_USER_MEM_SUPPORTED.
+ * Checking and error handling must happen outside this routine; it returns NULL
+ * if the allocation cannot be done (for any reason.)
+ */
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size),
+ PNG_ALLOCATED)
+{
+ /* Moved to png_malloc_base from png_malloc_default in 1.6.0; the DOS
+ * allocators have also been removed in 1.6.0, so any 16-bit system now has
+ * to implement a user memory handler. This checks to be sure it isn't
+ * called with big numbers.
+ */
+# ifdef PNG_MAX_MALLOC_64K
+ /* This is support for legacy systems which had segmented addressing
+ * limiting the maximum allocation size to 65536. It takes precedence
+ * over PNG_SIZE_MAX which is set to 65535 on true 16-bit systems.
+ *
+ * TODO: libpng-1.8: finally remove both cases.
+ */
+ if (size > 65536U) return NULL;
+# endif
+
+ /* This is checked too because the system malloc call below takes a (size_t).
+ */
+ if (size > PNG_SIZE_MAX) return NULL;
+
+# ifdef PNG_USER_MEM_SUPPORTED
+ if (png_ptr != NULL && png_ptr->malloc_fn != NULL)
+ return png_ptr->malloc_fn(png_constcast(png_structrp,png_ptr), size);
+# else
+ PNG_UNUSED(png_ptr)
+# endif
+
+ /* Use the system malloc */
+ return malloc((size_t)/*SAFE*/size); /* checked for truncation above */
+}
+
+#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
+ defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
+/* This is really here only to work round a spurious warning in GCC 4.6 and 4.7
+ * that arises because of the checks in png_realloc_array that are repeated in
+ * png_malloc_array.
+ */
+static png_voidp
+png_malloc_array_checked(png_const_structrp png_ptr, int nelements,
+ size_t element_size)
+{
+ png_alloc_size_t req = (png_alloc_size_t)nelements; /* known to be > 0 */
+
+ if (req <= PNG_SIZE_MAX/element_size)
+ return png_malloc_base(png_ptr, req * element_size);
+
+ /* The failure case when the request is too large */
+ return NULL;
+}
+
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_malloc_array,(png_const_structrp png_ptr, int nelements,
+ size_t element_size),PNG_ALLOCATED)
+{
+ if (nelements <= 0 || element_size == 0)
+ png_error(png_ptr, "internal error: array alloc");
+
+ return png_malloc_array_checked(png_ptr, nelements, element_size);
+}
+
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_realloc_array,(png_const_structrp png_ptr, png_const_voidp old_array,
+ int old_elements, int add_elements, size_t element_size),PNG_ALLOCATED)
+{
+ /* These are internal errors: */
+ if (add_elements <= 0 || element_size == 0 || old_elements < 0 ||
+ (old_array == NULL && old_elements > 0))
+ png_error(png_ptr, "internal error: array realloc");
+
+ /* Check for overflow on the elements count (so the caller does not have to
+ * check.)
+ */
+ if (add_elements <= INT_MAX - old_elements)
+ {
+ png_voidp new_array = png_malloc_array_checked(png_ptr,
+ old_elements+add_elements, element_size);
+
+ if (new_array != NULL)
+ {
+ /* Because png_malloc_array worked the size calculations below cannot
+ * overflow.
+ */
+ if (old_elements > 0)
+ memcpy(new_array, old_array, element_size*(unsigned)old_elements);
+
+ memset((char*)new_array + element_size*(unsigned)old_elements, 0,
+ element_size*(unsigned)add_elements);
+
+ return new_array;
+ }
+ }
+
+ return NULL; /* error */
+}
+#endif /* TEXT || sPLT || STORE_UNKNOWN_CHUNKS */
+
+/* Various functions that have different error handling are derived from this.
+ * png_malloc always exists, but if PNG_USER_MEM_SUPPORTED is defined a separate
+ * function png_malloc_default is also provided.
+ */
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
+{
+ png_voidp ret;
+
+ if (png_ptr == NULL)
+ return NULL;
+
+ ret = png_malloc_base(png_ptr, size);
+
+ if (ret == NULL)
+ png_error(png_ptr, "Out of memory"); /* 'm' means png_malloc */
+
+ return ret;
+}
+
+#ifdef PNG_USER_MEM_SUPPORTED
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc_default,(png_const_structrp png_ptr, png_alloc_size_t size),
+ PNG_ALLOCATED PNG_DEPRECATED)
+{
+ png_voidp ret;
+
+ if (png_ptr == NULL)
+ return NULL;
+
+ /* Passing 'NULL' here bypasses the application provided memory handler. */
+ ret = png_malloc_base(NULL/*use malloc*/, size);
+
+ if (ret == NULL)
+ png_error(png_ptr, "Out of Memory"); /* 'M' means png_malloc_default */
+
+ return ret;
+}
+#endif /* USER_MEM */
+
+/* This function was added at libpng version 1.2.3. The png_malloc_warn()
+ * function will issue a png_warning and return NULL instead of issuing a
+ * png_error, if it fails to allocate the requested memory.
+ */
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc_warn,(png_const_structrp png_ptr, png_alloc_size_t size),
+ PNG_ALLOCATED)
+{
+ if (png_ptr != NULL)
+ {
+ png_voidp ret = png_malloc_base(png_ptr, size);
+
+ if (ret != NULL)
+ return ret;
+
+ png_warning(png_ptr, "Out of memory");
+ }
+
+ return NULL;
+}
+
+/* Free a pointer allocated by png_malloc(). If ptr is NULL, return
+ * without taking any action.
+ */
+void PNGAPI
+png_free(png_const_structrp png_ptr, png_voidp ptr)
+{
+ if (png_ptr == NULL || ptr == NULL)
+ return;
+
+#ifdef PNG_USER_MEM_SUPPORTED
+ if (png_ptr->free_fn != NULL)
+ png_ptr->free_fn(png_constcast(png_structrp,png_ptr), ptr);
+
+ else
+ png_free_default(png_ptr, ptr);
+}
+
+PNG_FUNCTION(void,PNGAPI
+png_free_default,(png_const_structrp png_ptr, png_voidp ptr),PNG_DEPRECATED)
+{
+ if (png_ptr == NULL || ptr == NULL)
+ return;
+#endif /* USER_MEM */
+
+ free(ptr);
+}
+
+#ifdef PNG_USER_MEM_SUPPORTED
+/* This function is called when the application wants to use another method
+ * of allocating and freeing memory.
+ */
+void PNGAPI
+png_set_mem_fn(png_structrp png_ptr, png_voidp mem_ptr, png_malloc_ptr
+ malloc_fn, png_free_ptr free_fn)
+{
+ if (png_ptr != NULL)
+ {
+ png_ptr->mem_ptr = mem_ptr;
+ png_ptr->malloc_fn = malloc_fn;
+ png_ptr->free_fn = free_fn;
+ }
+}
+
+/* This function returns a pointer to the mem_ptr associated with the user
+ * functions. The application should free any memory associated with this
+ * pointer before png_write_destroy and png_read_destroy are called.
+ */
+png_voidp PNGAPI
+png_get_mem_ptr(png_const_structrp png_ptr)
+{
+ if (png_ptr == NULL)
+ return NULL;
+
+ return png_ptr->mem_ptr;
+}
+#endif /* USER_MEM */
+#endif /* READ || WRITE */
diff --git a/libs/imagequant/external/libpng/pngpread.c b/libs/imagequant/external/libpng/pngpread.c
new file mode 100644
index 00000000..0a3e822c
--- /dev/null
+++ b/libs/imagequant/external/libpng/pngpread.c
@@ -0,0 +1,937 @@
+/* pngpread.c - read a png file in push mode
+ *
+ * Copyright (c) 2018-2025 Cosmin Truta
+ * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+
+/* Push model modes */
+#define PNG_READ_SIG_MODE 0
+#define PNG_READ_CHUNK_MODE 1
+#define PNG_READ_IDAT_MODE 2
+#define PNG_READ_tEXt_MODE 4
+#define PNG_READ_zTXt_MODE 5
+#define PNG_READ_DONE_MODE 6
+#define PNG_READ_iTXt_MODE 7
+#define PNG_ERROR_MODE 8
+
+#define PNG_PUSH_SAVE_BUFFER_IF_FULL \
+if (png_ptr->push_length + 4 > png_ptr->buffer_size) \
+ { png_push_save_buffer(png_ptr); return; }
+#define PNG_PUSH_SAVE_BUFFER_IF_LT(N) \
+if (png_ptr->buffer_size < N) \
+ { png_push_save_buffer(png_ptr); return; }
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+/* Arrays to facilitate interlacing - use pass (0 - 6) as index. */
+
+/* Start of interlace block */
+static const png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+/* Offset to next interlace block */
+static const png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+/* Start of interlace block in the y direction */
+static const png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+/* Offset to next interlace block in the y direction */
+static const png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+
+/* TODO: Move these arrays to a common utility module to avoid duplication. */
+#endif
+
+void PNGAPI
+png_process_data(png_structrp png_ptr, png_inforp info_ptr,
+ png_bytep buffer, size_t buffer_size)
+{
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ png_push_restore_buffer(png_ptr, buffer, buffer_size);
+
+ while (png_ptr->buffer_size)
+ {
+ png_process_some_data(png_ptr, info_ptr);
+ }
+}
+
+size_t PNGAPI
+png_process_data_pause(png_structrp png_ptr, int save)
+{
+ if (png_ptr != NULL)
+ {
+ /* It's easiest for the caller if we do the save; then the caller doesn't
+ * have to supply the same data again:
+ */
+ if (save != 0)
+ png_push_save_buffer(png_ptr);
+ else
+ {
+ /* This includes any pending saved bytes: */
+ size_t remaining = png_ptr->buffer_size;
+ png_ptr->buffer_size = 0;
+
+ /* So subtract the saved buffer size, unless all the data
+ * is actually 'saved', in which case we just return 0
+ */
+ if (png_ptr->save_buffer_size < remaining)
+ return remaining - png_ptr->save_buffer_size;
+ }
+ }
+
+ return 0;
+}
+
+png_uint_32 PNGAPI
+png_process_data_skip(png_structrp png_ptr)
+{
+/* TODO: Deprecate and remove this API.
+ * Somewhere the implementation of this seems to have been lost,
+ * or abandoned. It was only to support some internal back-door access
+ * to png_struct) in libpng-1.4.x.
+ */
+ png_app_warning(png_ptr,
+"png_process_data_skip is not implemented in any current version of libpng");
+ return 0;
+}
+
+/* What we do with the incoming data depends on what we were previously
+ * doing before we ran out of data...
+ */
+void /* PRIVATE */
+png_process_some_data(png_structrp png_ptr, png_inforp info_ptr)
+{
+ if (png_ptr == NULL)
+ return;
+
+ switch (png_ptr->process_mode)
+ {
+ case PNG_READ_SIG_MODE:
+ {
+ png_push_read_sig(png_ptr, info_ptr);
+ break;
+ }
+
+ case PNG_READ_CHUNK_MODE:
+ {
+ png_push_read_chunk(png_ptr, info_ptr);
+ break;
+ }
+
+ case PNG_READ_IDAT_MODE:
+ {
+ png_push_read_IDAT(png_ptr);
+ break;
+ }
+
+ default:
+ {
+ png_ptr->buffer_size = 0;
+ break;
+ }
+ }
+}
+
+/* Read any remaining signature bytes from the stream and compare them with
+ * the correct PNG signature. It is possible that this routine is called
+ * with bytes already read from the signature, either because they have been
+ * checked by the calling application, or because of multiple calls to this
+ * routine.
+ */
+void /* PRIVATE */
+png_push_read_sig(png_structrp png_ptr, png_inforp info_ptr)
+{
+ size_t num_checked = png_ptr->sig_bytes; /* SAFE, does not exceed 8 */
+ size_t num_to_check = 8 - num_checked;
+
+ if (png_ptr->buffer_size < num_to_check)
+ {
+ num_to_check = png_ptr->buffer_size;
+ }
+
+ png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
+ num_to_check);
+ png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check);
+
+ if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check) != 0)
+ {
+ if (num_checked < 4 &&
+ png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4) != 0)
+ png_error(png_ptr, "Not a PNG file");
+
+ else
+ png_error(png_ptr, "PNG file corrupted by ASCII conversion");
+ }
+ else
+ {
+ if (png_ptr->sig_bytes >= 8)
+ {
+ png_ptr->process_mode = PNG_READ_CHUNK_MODE;
+ }
+ }
+}
+
+void /* PRIVATE */
+png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
+{
+ png_uint_32 chunk_name;
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ int keep; /* unknown handling method */
+#endif
+
+ /* First we make sure we have enough data for the 4-byte chunk name
+ * and the 4-byte chunk length before proceeding with decoding the
+ * chunk data. To fully decode each of these chunks, we also make
+ * sure we have enough data in the buffer for the 4-byte CRC at the
+ * end of every chunk (except IDAT, which is handled separately).
+ */
+ if ((png_ptr->mode & PNG_HAVE_CHUNK_HEADER) == 0)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_LT(8)
+ png_ptr->push_length = png_read_chunk_header(png_ptr);
+ png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
+ }
+
+ chunk_name = png_ptr->chunk_name;
+
+ if (chunk_name == png_IDAT)
+ {
+ if ((png_ptr->mode & PNG_AFTER_IDAT) != 0)
+ png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
+
+ /* If we reach an IDAT chunk, this means we have read all of the
+ * header chunks, and we can start reading the image (or if this
+ * is called after the image has been read - we have an error).
+ */
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_error(png_ptr, "Missing IHDR before IDAT");
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+ (png_ptr->mode & PNG_HAVE_PLTE) == 0)
+ png_error(png_ptr, "Missing PLTE before IDAT");
+
+ png_ptr->process_mode = PNG_READ_IDAT_MODE;
+
+ if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+ if ((png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) == 0)
+ if (png_ptr->push_length == 0)
+ return;
+
+ png_ptr->mode |= PNG_HAVE_IDAT;
+
+ if ((png_ptr->mode & PNG_AFTER_IDAT) != 0)
+ png_benign_error(png_ptr, "Too many IDATs found");
+ }
+
+ if (chunk_name == png_IHDR)
+ {
+ if (png_ptr->push_length != 13)
+ png_error(png_ptr, "Invalid IHDR length");
+
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_chunk(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+ else if (chunk_name == png_IEND)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_chunk(png_ptr, info_ptr, png_ptr->push_length);
+
+ png_ptr->process_mode = PNG_READ_DONE_MODE;
+ png_push_have_end(png_ptr, info_ptr);
+ }
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, keep);
+
+ if (chunk_name == png_PLTE)
+ png_ptr->mode |= PNG_HAVE_PLTE;
+ }
+#endif
+
+ else if (chunk_name == png_IDAT)
+ {
+ png_ptr->idat_size = png_ptr->push_length;
+ png_ptr->process_mode = PNG_READ_IDAT_MODE;
+ png_push_have_info(png_ptr, info_ptr);
+ png_ptr->zstream.avail_out =
+ (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
+ png_ptr->iwidth) + 1;
+ png_ptr->zstream.next_out = png_ptr->row_buf;
+ return;
+ }
+
+ else
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+ png_handle_chunk(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
+}
+
+void PNGCBAPI
+png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, size_t length)
+{
+ png_bytep ptr;
+
+ if (png_ptr == NULL)
+ return;
+
+ ptr = buffer;
+ if (png_ptr->save_buffer_size != 0)
+ {
+ size_t save_size;
+
+ if (length < png_ptr->save_buffer_size)
+ save_size = length;
+
+ else
+ save_size = png_ptr->save_buffer_size;
+
+ memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
+ length -= save_size;
+ ptr += save_size;
+ png_ptr->buffer_size -= save_size;
+ png_ptr->save_buffer_size -= save_size;
+ png_ptr->save_buffer_ptr += save_size;
+ }
+ if (length != 0 && png_ptr->current_buffer_size != 0)
+ {
+ size_t save_size;
+
+ if (length < png_ptr->current_buffer_size)
+ save_size = length;
+
+ else
+ save_size = png_ptr->current_buffer_size;
+
+ memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
+ png_ptr->buffer_size -= save_size;
+ png_ptr->current_buffer_size -= save_size;
+ png_ptr->current_buffer_ptr += save_size;
+ }
+}
+
+void /* PRIVATE */
+png_push_save_buffer(png_structrp png_ptr)
+{
+ if (png_ptr->save_buffer_size != 0)
+ {
+ if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
+ {
+ size_t i, istop;
+ png_bytep sp;
+ png_bytep dp;
+
+ istop = png_ptr->save_buffer_size;
+ for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
+ i < istop; i++, sp++, dp++)
+ {
+ *dp = *sp;
+ }
+ }
+ }
+ if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
+ png_ptr->save_buffer_max)
+ {
+ size_t new_max;
+ png_bytep old_buffer;
+
+ if (png_ptr->save_buffer_size > PNG_SIZE_MAX -
+ (png_ptr->current_buffer_size + 256))
+ {
+ png_error(png_ptr, "Potential overflow of save_buffer");
+ }
+
+ new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
+ old_buffer = png_ptr->save_buffer;
+ png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr,
+ (size_t)new_max);
+
+ if (png_ptr->save_buffer == NULL)
+ {
+ png_free(png_ptr, old_buffer);
+ png_error(png_ptr, "Insufficient memory for save_buffer");
+ }
+
+ if (old_buffer)
+ memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
+ else if (png_ptr->save_buffer_size)
+ png_error(png_ptr, "save_buffer error");
+ png_free(png_ptr, old_buffer);
+ png_ptr->save_buffer_max = new_max;
+ }
+ if (png_ptr->current_buffer_size)
+ {
+ memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
+ png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
+ png_ptr->save_buffer_size += png_ptr->current_buffer_size;
+ png_ptr->current_buffer_size = 0;
+ }
+ png_ptr->save_buffer_ptr = png_ptr->save_buffer;
+ png_ptr->buffer_size = 0;
+}
+
+void /* PRIVATE */
+png_push_restore_buffer(png_structrp png_ptr, png_bytep buffer,
+ size_t buffer_length)
+{
+ png_ptr->current_buffer = buffer;
+ png_ptr->current_buffer_size = buffer_length;
+ png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size;
+ png_ptr->current_buffer_ptr = png_ptr->current_buffer;
+}
+
+void /* PRIVATE */
+png_push_read_IDAT(png_structrp png_ptr)
+{
+ if ((png_ptr->mode & PNG_HAVE_CHUNK_HEADER) == 0)
+ {
+ png_byte chunk_length[4];
+ png_byte chunk_tag[4];
+
+ /* TODO: this code can be commoned up with the same code in push_read */
+ PNG_PUSH_SAVE_BUFFER_IF_LT(8)
+ png_push_fill_buffer(png_ptr, chunk_length, 4);
+ png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
+ png_reset_crc(png_ptr);
+ png_crc_read(png_ptr, chunk_tag, 4);
+ png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
+ png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
+
+ if (png_ptr->chunk_name != png_IDAT)
+ {
+ png_ptr->process_mode = PNG_READ_CHUNK_MODE;
+
+ if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
+ png_error(png_ptr, "Not enough compressed data");
+
+ return;
+ }
+
+ png_ptr->idat_size = png_ptr->push_length;
+ }
+
+ if (png_ptr->idat_size != 0 && png_ptr->save_buffer_size != 0)
+ {
+ size_t save_size = png_ptr->save_buffer_size;
+ png_uint_32 idat_size = png_ptr->idat_size;
+
+ /* We want the smaller of 'idat_size' and 'current_buffer_size', but they
+ * are of different types and we don't know which variable has the fewest
+ * bits. Carefully select the smaller and cast it to the type of the
+ * larger - this cannot overflow. Do not cast in the following test - it
+ * will break on either 16-bit or 64-bit platforms.
+ */
+ if (idat_size < save_size)
+ save_size = (size_t)idat_size;
+
+ else
+ idat_size = (png_uint_32)save_size;
+
+ png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
+
+ png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
+
+ png_ptr->idat_size -= idat_size;
+ png_ptr->buffer_size -= save_size;
+ png_ptr->save_buffer_size -= save_size;
+ png_ptr->save_buffer_ptr += save_size;
+ }
+
+ if (png_ptr->idat_size != 0 && png_ptr->current_buffer_size != 0)
+ {
+ size_t save_size = png_ptr->current_buffer_size;
+ png_uint_32 idat_size = png_ptr->idat_size;
+
+ /* We want the smaller of 'idat_size' and 'current_buffer_size', but they
+ * are of different types and we don't know which variable has the fewest
+ * bits. Carefully select the smaller and cast it to the type of the
+ * larger - this cannot overflow.
+ */
+ if (idat_size < save_size)
+ save_size = (size_t)idat_size;
+
+ else
+ idat_size = (png_uint_32)save_size;
+
+ png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
+
+ png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
+
+ png_ptr->idat_size -= idat_size;
+ png_ptr->buffer_size -= save_size;
+ png_ptr->current_buffer_size -= save_size;
+ png_ptr->current_buffer_ptr += save_size;
+ }
+
+ if (png_ptr->idat_size == 0)
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_LT(4)
+ png_crc_finish(png_ptr, 0);
+ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ png_ptr->zowner = 0;
+ }
+}
+
+void /* PRIVATE */
+png_process_IDAT_data(png_structrp png_ptr, png_bytep buffer,
+ size_t buffer_length)
+{
+ /* The caller checks for a non-zero buffer length. */
+ if (!(buffer_length > 0) || buffer == NULL)
+ png_error(png_ptr, "No IDAT data (internal error)");
+
+ /* This routine must process all the data it has been given
+ * before returning, calling the row callback as required to
+ * handle the uncompressed results.
+ */
+ png_ptr->zstream.next_in = buffer;
+ /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */
+ png_ptr->zstream.avail_in = (uInt)buffer_length;
+
+ /* Keep going until the decompressed data is all processed
+ * or the stream marked as finished.
+ */
+ while (png_ptr->zstream.avail_in > 0 &&
+ (png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
+ {
+ int ret;
+
+ /* We have data for zlib, but we must check that zlib
+ * has someplace to put the results. It doesn't matter
+ * if we don't expect any results -- it may be the input
+ * data is just the LZ end code.
+ */
+ if (!(png_ptr->zstream.avail_out > 0))
+ {
+ /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */
+ png_ptr->zstream.avail_out = (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth,
+ png_ptr->iwidth) + 1);
+
+ png_ptr->zstream.next_out = png_ptr->row_buf;
+ }
+
+ /* Using Z_SYNC_FLUSH here means that an unterminated
+ * LZ stream (a stream with a missing end code) can still
+ * be handled, otherwise (Z_NO_FLUSH) a future zlib
+ * implementation might defer output and therefore
+ * change the current behavior (see comments in inflate.c
+ * for why this doesn't happen at present with zlib 1.2.5).
+ */
+ ret = PNG_INFLATE(png_ptr, Z_SYNC_FLUSH);
+
+ /* Check for any failure before proceeding. */
+ if (ret != Z_OK && ret != Z_STREAM_END)
+ {
+ /* Terminate the decompression. */
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
+ png_ptr->zowner = 0;
+
+ /* This may be a truncated stream (missing or
+ * damaged end code). Treat that as a warning.
+ */
+ if (png_ptr->row_number >= png_ptr->num_rows ||
+ png_ptr->pass > 6)
+ png_warning(png_ptr, "Truncated compressed data in IDAT");
+
+ else
+ {
+ if (ret == Z_DATA_ERROR)
+ png_benign_error(png_ptr, "IDAT: ADLER32 checksum mismatch");
+ else
+ png_error(png_ptr, "Decompression error in IDAT");
+ }
+
+ /* Skip the check on unprocessed input */
+ return;
+ }
+
+ /* Did inflate output any data? */
+ if (png_ptr->zstream.next_out != png_ptr->row_buf)
+ {
+ /* Is this unexpected data after the last row?
+ * If it is, artificially terminate the LZ output
+ * here.
+ */
+ if (png_ptr->row_number >= png_ptr->num_rows ||
+ png_ptr->pass > 6)
+ {
+ /* Extra data. */
+ png_warning(png_ptr, "Extra compressed data in IDAT");
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
+ png_ptr->zowner = 0;
+
+ /* Do no more processing; skip the unprocessed
+ * input check below.
+ */
+ return;
+ }
+
+ /* Do we have a complete row? */
+ if (png_ptr->zstream.avail_out == 0)
+ png_push_process_row(png_ptr);
+ }
+
+ /* And check for the end of the stream. */
+ if (ret == Z_STREAM_END)
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
+ }
+
+ /* All the data should have been processed, if anything
+ * is left at this point we have bytes of IDAT data
+ * after the zlib end code.
+ */
+ if (png_ptr->zstream.avail_in > 0)
+ png_warning(png_ptr, "Extra compression data in IDAT");
+}
+
+void /* PRIVATE */
+png_push_process_row(png_structrp png_ptr)
+{
+ /* 1.5.6: row_info moved out of png_struct to a local here. */
+ png_row_info row_info;
+
+ row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */
+ row_info.color_type = png_ptr->color_type;
+ row_info.bit_depth = png_ptr->bit_depth;
+ row_info.channels = png_ptr->channels;
+ row_info.pixel_depth = png_ptr->pixel_depth;
+ row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
+
+ if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE)
+ {
+ if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST)
+ png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1,
+ png_ptr->prev_row + 1, png_ptr->row_buf[0]);
+ else
+ png_error(png_ptr, "bad adaptive filter value");
+ }
+
+ /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before
+ * 1.5.6, while the buffer really is this big in current versions of libpng
+ * it may not be in the future, so this was changed just to copy the
+ * interlaced row count:
+ */
+ memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+ if (png_ptr->transformations != 0)
+ png_do_read_transformations(png_ptr, &row_info);
+#endif
+
+ /* The transformed pixel depth should match the depth now in row_info. */
+ if (png_ptr->transformed_pixel_depth == 0)
+ {
+ png_ptr->transformed_pixel_depth = row_info.pixel_depth;
+ if (row_info.pixel_depth > png_ptr->maximum_pixel_depth)
+ png_error(png_ptr, "progressive row overflow");
+ }
+
+ else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth)
+ png_error(png_ptr, "internal progressive row size calculation error");
+
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ /* Expand interlaced rows to full size */
+ if (png_ptr->interlaced != 0 &&
+ (png_ptr->transformations & PNG_INTERLACE) != 0)
+ {
+ if (png_ptr->pass < 6)
+ png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
+ png_ptr->transformations);
+
+ switch (png_ptr->pass)
+ {
+ case 0:
+ {
+ int i;
+ for (i = 0; i < 8 && png_ptr->pass == 0; i++)
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr); /* Updates png_ptr->pass */
+ }
+
+ if (png_ptr->pass == 2) /* Pass 1 might be empty */
+ {
+ for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+
+ if (png_ptr->pass == 4 && png_ptr->height <= 4)
+ {
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+
+ if (png_ptr->pass == 6 && png_ptr->height <= 4)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ break;
+ }
+
+ case 1:
+ {
+ int i;
+ for (i = 0; i < 8 && png_ptr->pass == 1; i++)
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ if (png_ptr->pass == 2) /* Skip top 4 generated rows */
+ {
+ for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+
+ break;
+ }
+
+ case 2:
+ {
+ int i;
+
+ for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ if (png_ptr->pass == 4) /* Pass 3 might be empty */
+ {
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+
+ break;
+ }
+
+ case 3:
+ {
+ int i;
+
+ for (i = 0; i < 4 && png_ptr->pass == 3; i++)
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ if (png_ptr->pass == 4) /* Skip top two generated rows */
+ {
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+
+ break;
+ }
+
+ case 4:
+ {
+ int i;
+
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ if (png_ptr->pass == 6) /* Pass 5 might be empty */
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ break;
+ }
+
+ case 5:
+ {
+ int i;
+
+ for (i = 0; i < 2 && png_ptr->pass == 5; i++)
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ if (png_ptr->pass == 6) /* Skip top generated row */
+ {
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+
+ break;
+ }
+
+ default:
+ case 6:
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr);
+
+ if (png_ptr->pass != 6)
+ break;
+
+ png_push_have_row(png_ptr, NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+ }
+ else
+#endif
+ {
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+ png_read_push_finish_row(png_ptr);
+ }
+}
+
+void /* PRIVATE */
+png_read_push_finish_row(png_structrp png_ptr)
+{
+ png_ptr->row_number++;
+ if (png_ptr->row_number < png_ptr->num_rows)
+ return;
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ if (png_ptr->interlaced != 0)
+ {
+ png_ptr->row_number = 0;
+ memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+
+ do
+ {
+ png_ptr->pass++;
+ if ((png_ptr->pass == 1 && png_ptr->width < 5) ||
+ (png_ptr->pass == 3 && png_ptr->width < 3) ||
+ (png_ptr->pass == 5 && png_ptr->width < 2))
+ png_ptr->pass++;
+
+ if (png_ptr->pass > 7)
+ png_ptr->pass--;
+
+ if (png_ptr->pass >= 7)
+ break;
+
+ png_ptr->iwidth = (png_ptr->width +
+ png_pass_inc[png_ptr->pass] - 1 -
+ png_pass_start[png_ptr->pass]) /
+ png_pass_inc[png_ptr->pass];
+
+ if ((png_ptr->transformations & PNG_INTERLACE) != 0)
+ break;
+
+ png_ptr->num_rows = (png_ptr->height +
+ png_pass_yinc[png_ptr->pass] - 1 -
+ png_pass_ystart[png_ptr->pass]) /
+ png_pass_yinc[png_ptr->pass];
+
+ } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
+ }
+#endif /* READ_INTERLACING */
+}
+
+void /* PRIVATE */
+png_push_have_info(png_structrp png_ptr, png_inforp info_ptr)
+{
+ if (png_ptr->info_fn != NULL)
+ (*(png_ptr->info_fn))(png_ptr, info_ptr);
+}
+
+void /* PRIVATE */
+png_push_have_end(png_structrp png_ptr, png_inforp info_ptr)
+{
+ if (png_ptr->end_fn != NULL)
+ (*(png_ptr->end_fn))(png_ptr, info_ptr);
+}
+
+void /* PRIVATE */
+png_push_have_row(png_structrp png_ptr, png_bytep row)
+{
+ if (png_ptr->row_fn != NULL)
+ (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,
+ (int)png_ptr->pass);
+}
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+void PNGAPI
+png_progressive_combine_row(png_const_structrp png_ptr, png_bytep old_row,
+ png_const_bytep new_row)
+{
+ if (png_ptr == NULL)
+ return;
+
+ /* new_row is a flag here - if it is NULL then the app callback was called
+ * from an empty row (see the calls to png_struct::row_fn below), otherwise
+ * it must be png_ptr->row_buf+1
+ */
+ if (new_row != NULL)
+ png_combine_row(png_ptr, old_row, 1/*blocky display*/);
+}
+#endif /* READ_INTERLACING */
+
+void PNGAPI
+png_set_progressive_read_fn(png_structrp png_ptr, png_voidp progressive_ptr,
+ png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
+ png_progressive_end_ptr end_fn)
+{
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->info_fn = info_fn;
+ png_ptr->row_fn = row_fn;
+ png_ptr->end_fn = end_fn;
+
+ png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
+}
+
+png_voidp PNGAPI
+png_get_progressive_ptr(png_const_structrp png_ptr)
+{
+ if (png_ptr == NULL)
+ return NULL;
+
+ return png_ptr->io_ptr;
+}
+#endif /* PROGRESSIVE_READ */
diff --git a/libs/imagequant/external/libpng/pngpriv.h b/libs/imagequant/external/libpng/pngpriv.h
new file mode 100644
index 00000000..cb44a6ae
--- /dev/null
+++ b/libs/imagequant/external/libpng/pngpriv.h
@@ -0,0 +1,2221 @@
+/* pngpriv.h - private declarations for use inside libpng
+ *
+ * Copyright (c) 2018-2025 Cosmin Truta
+ * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+/* The symbols declared in this file (including the functions declared
+ * as extern) are PRIVATE. They are not part of the libpng public
+ * interface, and are not recommended for use by regular applications.
+ * Some of them may become public in the future; others may stay private,
+ * change in an incompatible way, or even disappear.
+ * Although the libpng users are not forbidden to include this header,
+ * they should be well aware of the issues that may arise from doing so.
+ */
+
+
+/* pngpriv.h must be included first in each translation unit inside libpng.
+ * On the other hand, it must not be included at all, directly or indirectly,
+ * by any application code that uses the libpng API.
+ */
+#ifndef PNGPRIV_H
+# define PNGPRIV_H
+#else
+# error Duplicate inclusion of pngpriv.h; please check the libpng source files
+#endif
+
+#if defined(PNG_H) || defined(PNGCONF_H) || defined(PNGLCONF_H)
+# error This file must not be included by applications; please include
+#endif
+
+/* Feature Test Macros. The following are defined here to ensure that correctly
+ * implemented libraries reveal the APIs libpng needs to build and hide those
+ * that are not needed and potentially damaging to the compilation.
+ *
+ * Feature Test Macros must be defined before any system header is included (see
+ * POSIX 1003.1 2.8.2 "POSIX Symbols."
+ *
+ * These macros only have an effect if the operating system supports either
+ * POSIX 1003.1 or C99, or both. On other operating systems (particularly
+ * Windows/Visual Studio) there is no effect; the OS specific tests below are
+ * still required (as of 2011-05-02.)
+ */
+#ifndef _POSIX_SOURCE
+# define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
+#endif
+
+#ifndef PNG_VERSION_INFO_ONLY
+/* Standard library headers not required by png.h: */
+# include
+# include
+#endif
+
+#define PNGLIB_BUILD /*libpng is being built, not used*/
+
+/* If HAVE_CONFIG_H is defined during the build then the build system must
+ * provide an appropriate "config.h" file on the include path. The header file
+ * must provide definitions as required below (search for "HAVE_CONFIG_H");
+ * see configure.ac for more details of the requirements. The macro
+ * "PNG_NO_CONFIG_H" is provided for maintainers to test for dependencies on
+ * 'configure'; define this macro to prevent the configure build including the
+ * configure generated config.h. Libpng is expected to compile without *any*
+ * special build system support on a reasonably ANSI-C compliant system.
+ */
+#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
+# include
+ /* Pick up the definition of 'restrict' from config.h if it was read: */
+# define PNG_RESTRICT restrict
+#endif
+
+/* To support symbol prefixing it is necessary to know *before* including png.h
+ * whether the fixed point (and maybe other) APIs are exported, because if they
+ * are not internal definitions may be required. This is handled below just
+ * before png.h is included, but load the configuration now if it is available.
+ */
+#include "pnglibconf.h"
+
+/* Local renames may change non-exported API functions from png.h */
+#if defined(PNG_PREFIX) && !defined(PNGPREFIX_H)
+# include "pngprefix.h"
+#endif
+
+#ifdef PNG_USER_CONFIG
+# include "pngusr.h"
+ /* These should have been defined in pngusr.h */
+# ifndef PNG_USER_PRIVATEBUILD
+# define PNG_USER_PRIVATEBUILD "Custom libpng build"
+# endif
+# ifndef PNG_USER_DLLFNAME_POSTFIX
+# define PNG_USER_DLLFNAME_POSTFIX "Cb"
+# endif
+#endif
+
+/* Compile time options.
+ * =====================
+ * In a multi-arch build the compiler may compile the code several times for the
+ * same object module, producing different binaries for different architectures.
+ * When this happens configure-time setting of the target host options cannot be
+ * done and this interferes with the handling of the ARM NEON optimizations, and
+ * possibly other similar optimizations. Put additional tests here; in general
+ * this is needed when the same option can be changed at both compile time and
+ * run time depending on the target OS (i.e. iOS vs Android.)
+ *
+ * NOTE: symbol prefixing does not pass $(CFLAGS) to the preprocessor, because
+ * this is not possible with certain compilers (Oracle SUN OS CC), as a result
+ * it is necessary to ensure that all extern functions that *might* be used
+ * regardless of $(CFLAGS) get declared in this file. The test on __ARM_NEON__
+ * below is one example of this behavior because it is controlled by the
+ * presence or not of -mfpu=neon on the GCC command line, it is possible to do
+ * this in $(CC), e.g. "CC=gcc -mfpu=neon", but people who build libpng rarely
+ * do this.
+ */
+#ifndef PNG_ARM_NEON_OPT
+ /* ARM NEON optimizations are being controlled by the compiler settings,
+ * typically the target FPU. If the FPU has been set to NEON (-mfpu=neon
+ * with GCC) then the compiler will define __ARM_NEON__ and we can rely
+ * unconditionally on NEON instructions not crashing, otherwise we must
+ * disable use of NEON instructions.
+ *
+ * NOTE: at present these optimizations depend on 'ALIGNED_MEMORY', so they
+ * can only be turned on automatically if that is supported too. If
+ * PNG_ARM_NEON_OPT is set in CPPFLAGS (to >0) then arm/arm_init.c will fail
+ * to compile with an appropriate #error if ALIGNED_MEMORY has been turned
+ * off.
+ *
+ * Note that gcc-4.9 defines __ARM_NEON instead of the deprecated
+ * __ARM_NEON__, so we check both variants.
+ *
+ * To disable ARM_NEON optimizations entirely, and skip compiling the
+ * associated assembler code, pass --enable-arm-neon=no to configure
+ * or put -DPNG_ARM_NEON_OPT=0 in CPPFLAGS.
+ */
+# if (defined(__ARM_NEON__) || defined(__ARM_NEON)) && \
+ defined(PNG_ALIGNED_MEMORY_SUPPORTED)
+# define PNG_ARM_NEON_OPT 2
+# else
+# define PNG_ARM_NEON_OPT 0
+# endif
+#endif
+
+#ifndef PNG_RISCV_RVV_OPT
+ /* RISCV_RVV optimizations are being controlled by the compiler settings,
+ * typically the target compiler will define __riscv but the rvv extension
+ * availability has to be explicitly stated. This is why if no
+ * PNG_RISCV_RVV_OPT was defined then a runtime check will be executed.
+ *
+ * To enable RISCV_RVV optimizations unconditionally, and compile the
+ * associated code, pass --enable-riscv-rvv=yes or --enable-riscv-rvv=on
+ * to configure or put -DPNG_RISCV_RVV_OPT=2 in CPPFLAGS.
+ */
+
+# if defined(__riscv) && defined(PNG_ALIGNED_MEMORY_SUPPORTED)
+# define PNG_RISCV_RVV_OPT 1
+# else
+# define PNG_RISCV_RVV_OPT 0
+# endif
+#endif
+
+#if PNG_ARM_NEON_OPT > 0
+ /* NEON optimizations are to be at least considered by libpng, so enable the
+ * callbacks to do this.
+ */
+# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_neon
+# ifndef PNG_ARM_NEON_IMPLEMENTATION
+ /* Use the intrinsics code by default. */
+# define PNG_ARM_NEON_IMPLEMENTATION 1
+# endif
+#else /* PNG_ARM_NEON_OPT == 0 */
+# define PNG_ARM_NEON_IMPLEMENTATION 0
+#endif /* PNG_ARM_NEON_OPT > 0 */
+
+#ifndef PNG_MIPS_MSA_OPT
+# if defined(__mips_msa) && (__mips_isa_rev >= 5) && \
+ defined(PNG_ALIGNED_MEMORY_SUPPORTED)
+# define PNG_MIPS_MSA_OPT 2
+# else
+# define PNG_MIPS_MSA_OPT 0
+# endif
+#endif
+
+#ifndef PNG_MIPS_MMI_OPT
+# ifdef PNG_MIPS_MMI
+# if defined(__mips_loongson_mmi) && (_MIPS_SIM == _ABI64) && \
+ defined(PNG_ALIGNED_MEMORY_SUPPORTED)
+# define PNG_MIPS_MMI_OPT 1
+# else
+# define PNG_MIPS_MMI_OPT 0
+# endif
+# else
+# define PNG_MIPS_MMI_OPT 0
+# endif
+#endif
+
+#ifndef PNG_POWERPC_VSX_OPT
+# if defined(__PPC64__) && defined(__ALTIVEC__) && defined(__VSX__)
+# define PNG_POWERPC_VSX_OPT 2
+# else
+# define PNG_POWERPC_VSX_OPT 0
+# endif
+#endif
+
+#ifndef PNG_LOONGARCH_LSX_OPT
+# if defined(__loongarch_sx)
+# define PNG_LOONGARCH_LSX_OPT 1
+# else
+# define PNG_LOONGARCH_LSX_OPT 0
+# endif
+#endif
+
+#ifndef PNG_INTEL_SSE_OPT
+# ifdef PNG_INTEL_SSE
+ /* Only check for SSE if the build configuration has been modified to
+ * enable SSE optimizations. This means that these optimizations will
+ * be off by default. See contrib/intel for more details.
+ */
+# if defined(__SSE4_1__) || defined(__AVX__) || defined(__SSSE3__) || \
+ defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \
+ (defined(_M_IX86_FP) && _M_IX86_FP >= 2)
+# define PNG_INTEL_SSE_OPT 1
+# else
+# define PNG_INTEL_SSE_OPT 0
+# endif
+# else
+# define PNG_INTEL_SSE_OPT 0
+# endif
+#endif
+
+#if PNG_INTEL_SSE_OPT > 0
+# ifndef PNG_INTEL_SSE_IMPLEMENTATION
+# if defined(__SSE4_1__) || defined(__AVX__)
+ /* We are not actually using AVX, but checking for AVX is the best
+ way we can detect SSE4.1 and SSSE3 on MSVC.
+ */
+# define PNG_INTEL_SSE_IMPLEMENTATION 3
+# elif defined(__SSSE3__)
+# define PNG_INTEL_SSE_IMPLEMENTATION 2
+# elif defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \
+ (defined(_M_IX86_FP) && _M_IX86_FP >= 2)
+# define PNG_INTEL_SSE_IMPLEMENTATION 1
+# else
+# define PNG_INTEL_SSE_IMPLEMENTATION 0
+# endif
+# endif
+
+# if PNG_INTEL_SSE_IMPLEMENTATION > 0
+# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_sse2
+# endif
+#else
+# define PNG_INTEL_SSE_IMPLEMENTATION 0
+#endif
+
+#if PNG_MIPS_MSA_OPT > 0
+# ifndef PNG_MIPS_MSA_IMPLEMENTATION
+# if defined(__mips_msa)
+# if defined(__clang__)
+# elif defined(__GNUC__)
+# if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 7)
+# define PNG_MIPS_MSA_IMPLEMENTATION 2
+# endif /* no GNUC support */
+# endif /* __GNUC__ */
+# else /* !defined __mips_msa */
+# define PNG_MIPS_MSA_IMPLEMENTATION 2
+# endif /* __mips_msa */
+# endif /* !PNG_MIPS_MSA_IMPLEMENTATION */
+
+# ifndef PNG_MIPS_MSA_IMPLEMENTATION
+# define PNG_MIPS_MSA_IMPLEMENTATION 1
+# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_mips
+# endif
+#else
+# define PNG_MIPS_MSA_IMPLEMENTATION 0
+#endif /* PNG_MIPS_MSA_OPT > 0 */
+
+#if PNG_MIPS_MMI_OPT > 0
+# ifndef PNG_MIPS_MMI_IMPLEMENTATION
+# if defined(__mips_loongson_mmi) && (_MIPS_SIM == _ABI64)
+# define PNG_MIPS_MMI_IMPLEMENTATION 2
+# else /* !defined __mips_loongson_mmi || _MIPS_SIM != _ABI64 */
+# define PNG_MIPS_MMI_IMPLEMENTATION 0
+# endif /* __mips_loongson_mmi && _MIPS_SIM == _ABI64 */
+# endif /* !PNG_MIPS_MMI_IMPLEMENTATION */
+
+# if PNG_MIPS_MMI_IMPLEMENTATION > 0
+# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_mips
+# endif
+#else
+# define PNG_MIPS_MMI_IMPLEMENTATION 0
+#endif /* PNG_MIPS_MMI_OPT > 0 */
+
+#if PNG_POWERPC_VSX_OPT > 0
+# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_vsx
+# define PNG_POWERPC_VSX_IMPLEMENTATION 1
+#else
+# define PNG_POWERPC_VSX_IMPLEMENTATION 0
+#endif
+
+#if PNG_LOONGARCH_LSX_OPT > 0
+# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_lsx
+# define PNG_LOONGARCH_LSX_IMPLEMENTATION 1
+#else
+# define PNG_LOONGARCH_LSX_IMPLEMENTATION 0
+#endif
+
+#if PNG_RISCV_RVV_OPT > 0
+# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_rvv
+# ifndef PNG_RISCV_RVV_IMPLEMENTATION
+ /* Use the intrinsics code by default. */
+# define PNG_RISCV_RVV_IMPLEMENTATION 1
+# endif
+#else
+# define PNG_RISCV_RVV_IMPLEMENTATION 0
+#endif
+
+/* Is this a build of a DLL where compilation of the object modules requires
+ * different preprocessor settings to those required for a simple library? If
+ * so PNG_BUILD_DLL must be set.
+ *
+ * If libpng is used inside a DLL but that DLL does not export the libpng APIs
+ * PNG_BUILD_DLL must not be set. To avoid the code below kicking in build a
+ * static library of libpng then link the DLL against that.
+ */
+#ifndef PNG_BUILD_DLL
+# ifdef DLL_EXPORT
+ /* This is set by libtool when files are compiled for a DLL; libtool
+ * always compiles twice, even on systems where it isn't necessary. Set
+ * PNG_BUILD_DLL in case it is necessary:
+ */
+# define PNG_BUILD_DLL
+# else
+# ifdef _WINDLL
+ /* This is set by the Microsoft Visual Studio IDE in projects that
+ * build a DLL. It can't easily be removed from those projects (it
+ * isn't visible in the Visual Studio UI) so it is a fairly reliable
+ * indication that PNG_IMPEXP needs to be set to the DLL export
+ * attributes.
+ */
+# define PNG_BUILD_DLL
+# else
+# ifdef __DLL__
+ /* This is set by the Borland C system when compiling for a DLL
+ * (as above.)
+ */
+# define PNG_BUILD_DLL
+# else
+ /* Add additional compiler cases here. */
+# endif
+# endif
+# endif
+#endif /* Setting PNG_BUILD_DLL if required */
+
+/* See pngconf.h for more details: the builder of the library may set this on
+ * the command line to the right thing for the specific compilation system or it
+ * may be automagically set above (at present we know of no system where it does
+ * need to be set on the command line.)
+ *
+ * PNG_IMPEXP must be set here when building the library to prevent pngconf.h
+ * setting it to the "import" setting for a DLL build.
+ */
+#ifndef PNG_IMPEXP
+# ifdef PNG_BUILD_DLL
+# define PNG_IMPEXP PNG_DLL_EXPORT
+# else
+ /* Not building a DLL, or the DLL doesn't require specific export
+ * definitions.
+ */
+# define PNG_IMPEXP
+# endif
+#endif
+
+/* No warnings for private or deprecated functions in the build: */
+#ifndef PNG_DEPRECATED
+# define PNG_DEPRECATED
+#endif
+#ifndef PNG_PRIVATE
+# define PNG_PRIVATE
+#endif
+
+/* Symbol preprocessing support.
+ *
+ * To enable listing global, but internal, symbols the following macros should
+ * always be used to declare an extern data or function object in this file.
+ */
+#ifndef PNG_INTERNAL_DATA
+# define PNG_INTERNAL_DATA(type, name, array) PNG_LINKAGE_DATA type name array
+#endif
+
+#ifndef PNG_INTERNAL_FUNCTION
+# define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\
+ PNG_LINKAGE_FUNCTION PNG_FUNCTION(type, name, args, PNG_EMPTY attributes)
+#endif
+
+#ifndef PNG_INTERNAL_CALLBACK
+# define PNG_INTERNAL_CALLBACK(type, name, args, attributes)\
+ PNG_LINKAGE_CALLBACK PNG_FUNCTION(type, (PNGCBAPI name), args,\
+ PNG_EMPTY attributes)
+#endif
+
+/* If floating or fixed point APIs are disabled they may still be compiled
+ * internally. To handle this make sure they are declared as the appropriate
+ * internal extern function (otherwise the symbol prefixing stuff won't work and
+ * the functions will be used without definitions.)
+ *
+ * NOTE: although all the API functions are declared here they are not all
+ * actually built! Because the declarations are still made it is necessary to
+ * fake out types that they depend on.
+ */
+#ifndef PNG_FP_EXPORT
+# ifndef PNG_FLOATING_POINT_SUPPORTED
+# define PNG_FP_EXPORT(ordinal, type, name, args)\
+ PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
+# ifndef PNG_VERSION_INFO_ONLY
+ typedef struct png_incomplete png_double;
+ typedef png_double* png_doublep;
+ typedef const png_double* png_const_doublep;
+ typedef png_double** png_doublepp;
+# endif
+# endif
+#endif
+#ifndef PNG_FIXED_EXPORT
+# ifndef PNG_FIXED_POINT_SUPPORTED
+# define PNG_FIXED_EXPORT(ordinal, type, name, args)\
+ PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
+# endif
+#endif
+
+#include "png.h"
+
+/* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
+#ifndef PNG_DLL_EXPORT
+# define PNG_DLL_EXPORT
+#endif
+
+/* This is a global switch to set the compilation for an installed system
+ * (a release build). It can be set for testing debug builds to ensure that
+ * they will compile when the build type is switched to RC or STABLE, the
+ * default is just to use PNG_LIBPNG_BUILD_BASE_TYPE. Set this in CPPFLAGS
+ * with either:
+ *
+ * -DPNG_RELEASE_BUILD Turns on the release compile path
+ * -DPNG_RELEASE_BUILD=0 Turns it off
+ * or in your pngusr.h with
+ * #define PNG_RELEASE_BUILD=1 Turns on the release compile path
+ * #define PNG_RELEASE_BUILD=0 Turns it off
+ */
+#ifndef PNG_RELEASE_BUILD
+# define PNG_RELEASE_BUILD (PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC)
+#endif
+
+/* SECURITY and SAFETY:
+ *
+ * libpng is built with support for internal limits on image dimensions and
+ * memory usage. These are documented in scripts/pnglibconf.dfa of the
+ * source and recorded in the machine generated header file pnglibconf.h.
+ */
+
+/* If you are running on a machine where you cannot allocate more
+ * than 64K of memory at once, uncomment this. While libpng will not
+ * normally need that much memory in a chunk (unless you load up a very
+ * large file), zlib needs to know how big of a chunk it can use, and
+ * libpng thus makes sure to check any memory allocation to verify it
+ * will fit into memory.
+ *
+ * zlib provides 'MAXSEG_64K' which, if defined, indicates the
+ * same limit and pngconf.h (already included) sets the limit
+ * if certain operating systems are detected.
+ */
+#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
+# define PNG_MAX_MALLOC_64K
+#endif
+
+#ifndef PNG_UNUSED
+/* Unused formal parameter warnings are silenced using the following macro
+ * which is expected to have no bad effects on performance (optimizing
+ * compilers will probably remove it entirely). Note that if you replace
+ * it with something other than whitespace, you must include the terminating
+ * semicolon.
+ */
+# define PNG_UNUSED(param) (void)param;
+#endif
+
+/* Just a little check that someone hasn't tried to define something
+ * contradictory.
+ */
+#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
+# undef PNG_ZBUF_SIZE
+# define PNG_ZBUF_SIZE 65536L
+#endif
+
+/* If warnings or errors are turned off the code is disabled or redirected here.
+ * From 1.5.4 functions have been added to allow very limited formatting of
+ * error and warning messages - this code will also be disabled here.
+ */
+#ifdef PNG_WARNINGS_SUPPORTED
+# define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
+#else
+# define png_warning_parameter(p,number,string) ((void)0)
+# define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
+# define png_warning_parameter_signed(p,number,format,value) ((void)0)
+# define png_formatted_warning(pp,p,message) ((void)(pp))
+# define PNG_WARNING_PARAMETERS(p)
+#endif
+#ifndef PNG_ERROR_TEXT_SUPPORTED
+# define png_fixed_error(s1,s2) png_err(s1)
+#endif
+
+/* Some fixed point APIs are still required even if not exported because
+ * they get used by the corresponding floating point APIs. This magic
+ * deals with this:
+ */
+#ifdef PNG_FIXED_POINT_SUPPORTED
+# define PNGFAPI PNGAPI
+#else
+# define PNGFAPI /* PRIVATE */
+#endif
+
+#ifndef PNG_VERSION_INFO_ONLY
+/* Other defines specific to compilers can go here. Try to keep
+ * them inside an appropriate ifdef/endif pair for portability.
+ */
+
+/* C allows up-casts from (void*) to any pointer and (const void*) to any
+ * pointer to a const object. C++ regards this as a type error and requires an
+ * explicit, static, cast and provides the static_cast<> rune to ensure that
+ * const is not cast away.
+ */
+#ifdef __cplusplus
+# define png_voidcast(type, value) static_cast(value)
+# define png_constcast(type, value) const_cast(value)
+# define png_aligncast(type, value) \
+ static_cast(static_cast(value))
+# define png_aligncastconst(type, value) \
+ static_cast(static_cast(value))
+#else
+# define png_voidcast(type, value) (value)
+# define png_constcast(type, value) ((type)(void*)(const void*)(value))
+# define png_aligncast(type, value) ((void*)(value))
+# define png_aligncastconst(type, value) ((const void*)(value))
+#endif /* __cplusplus */
+
+#if defined(PNG_FLOATING_POINT_SUPPORTED) ||\
+ defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
+ /* png.c requires the following ANSI-C constants if the conversion of
+ * floating point to ASCII is implemented therein:
+ *
+ * DBL_DIG Maximum number of decimal digits (can be set to any constant)
+ * DBL_MIN Smallest normalized fp number (can be set to an arbitrary value)
+ * DBL_MAX Maximum floating point number (can be set to an arbitrary value)
+ */
+# include
+
+# include
+
+# if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
+ /* Amiga SAS/C: We must include builtin FPU functions when compiling using
+ * MATH=68881
+ */
+# include
+# endif
+#endif
+
+/* This provides the non-ANSI (far) memory allocation routines. */
+#if defined(__TURBOC__) && defined(__MSDOS__)
+# include
+# include
+#endif
+
+#if defined(_WIN32) || defined(__WIN32__) || defined(__NT__)
+# include
+#endif
+#endif /* PNG_VERSION_INFO_ONLY */
+
+/* Moved here around 1.5.0beta36 from pngconf.h */
+/* Users may want to use these so they are not private. Any library
+ * functions that are passed far data must be model-independent.
+ */
+
+/* Platform-independent functions */
+#ifndef PNG_ABORT
+# define PNG_ABORT() abort()
+#endif
+
+/* These macros may need to be architecture dependent. */
+#define PNG_ALIGN_NONE 0 /* do not use data alignment */
+#define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
+#ifdef offsetof
+# define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
+#else
+# define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
+#endif
+#define PNG_ALIGN_SIZE 3 /* use sizeof to determine alignment */
+
+#ifndef PNG_ALIGN_TYPE
+ /* Default to using aligned access optimizations and requiring alignment to a
+ * multiple of the data type size. Override in a compiler specific fashion
+ * if necessary by inserting tests here:
+ */
+# define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
+#endif
+
+#if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
+ /* This is used because in some compiler implementations non-aligned
+ * structure members are supported, so the offsetof approach below fails.
+ * Set PNG_ALIGN_SIZE=0 for compiler combinations where unaligned access
+ * is good for performance. Do not do this unless you have tested the
+ * result and understand it.
+ */
+# define png_alignof(type) (sizeof(type))
+#else
+# if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
+# define png_alignof(type) offsetof(struct{char c; type t;}, t)
+# else
+# if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
+# define png_alignof(type) 1
+# endif
+ /* Else leave png_alignof undefined to prevent use thereof */
+# endif
+#endif
+
+/* This implicitly assumes alignment is always a multiple of 2. */
+#ifdef png_alignof
+# define png_isaligned(ptr, type) \
+ (((type)(size_t)((const void*)(ptr)) & (type)(png_alignof(type)-1)) == 0)
+#else
+# define png_isaligned(ptr, type) 0
+#endif
+
+/* End of memory model/platform independent support */
+/* End of 1.5.0beta36 move from pngconf.h */
+
+/* CONSTANTS and UTILITY MACROS
+ * These are used internally by libpng and not exposed in the API
+ */
+
+/* Various modes of operation. Note that after an init, mode is set to
+ * zero automatically when the structure is created. Three of these
+ * are defined in png.h because they need to be visible to applications
+ * that call png_set_unknown_chunk().
+ */
+/* #define PNG_HAVE_IHDR 0x01U (defined in png.h) */
+/* #define PNG_HAVE_PLTE 0x02U (defined in png.h) */
+#define PNG_HAVE_IDAT 0x04U
+/* #define PNG_AFTER_IDAT 0x08U (defined in png.h) */
+#define PNG_HAVE_IEND 0x10U
+ /* 0x20U (unused) */
+ /* 0x40U (unused) */
+ /* 0x80U (unused) */
+#define PNG_HAVE_CHUNK_HEADER 0x100U
+#define PNG_WROTE_tIME 0x200U
+#define PNG_WROTE_INFO_BEFORE_PLTE 0x400U
+#define PNG_BACKGROUND_IS_GRAY 0x800U
+#define PNG_HAVE_PNG_SIGNATURE 0x1000U
+#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000U /* Have another chunk after IDAT */
+#define PNG_WROTE_eXIf 0x4000U
+#define PNG_IS_READ_STRUCT 0x8000U /* Else is a write struct */
+
+/* Flags for the transformations the PNG library does on the image data */
+#define PNG_BGR 0x0001U
+#define PNG_INTERLACE 0x0002U
+#define PNG_PACK 0x0004U
+#define PNG_SHIFT 0x0008U
+#define PNG_SWAP_BYTES 0x0010U
+#define PNG_INVERT_MONO 0x0020U
+#define PNG_QUANTIZE 0x0040U
+#define PNG_COMPOSE 0x0080U /* Was PNG_BACKGROUND */
+#define PNG_BACKGROUND_EXPAND 0x0100U
+#define PNG_EXPAND_16 0x0200U /* Added to libpng 1.5.2 */
+#define PNG_16_TO_8 0x0400U /* Becomes 'chop' in 1.5.4 */
+#define PNG_RGBA 0x0800U
+#define PNG_EXPAND 0x1000U
+#define PNG_GAMMA 0x2000U
+#define PNG_GRAY_TO_RGB 0x4000U
+#define PNG_FILLER 0x8000U
+#define PNG_PACKSWAP 0x10000U
+#define PNG_SWAP_ALPHA 0x20000U
+#define PNG_STRIP_ALPHA 0x40000U
+#define PNG_INVERT_ALPHA 0x80000U
+#define PNG_USER_TRANSFORM 0x100000U
+#define PNG_RGB_TO_GRAY_ERR 0x200000U
+#define PNG_RGB_TO_GRAY_WARN 0x400000U
+#define PNG_RGB_TO_GRAY 0x600000U /* two bits, RGB_TO_GRAY_ERR|WARN */
+#define PNG_ENCODE_ALPHA 0x800000U /* Added to libpng-1.5.4 */
+#define PNG_ADD_ALPHA 0x1000000U /* Added to libpng-1.2.7 */
+#define PNG_EXPAND_tRNS 0x2000000U /* Added to libpng-1.2.9 */
+#define PNG_SCALE_16_TO_8 0x4000000U /* Added to libpng-1.5.4 */
+ /* 0x8000000U unused */
+ /* 0x10000000U unused */
+ /* 0x20000000U unused */
+ /* 0x40000000U unused */
+/* Flags for png_create_struct */
+#define PNG_STRUCT_PNG 0x0001U
+#define PNG_STRUCT_INFO 0x0002U
+
+/* Flags for the png_ptr->flags rather than declaring a byte for each one */
+#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001U
+#define PNG_FLAG_ZSTREAM_INITIALIZED 0x0002U /* Added to libpng-1.6.0 */
+ /* 0x0004U unused */
+#define PNG_FLAG_ZSTREAM_ENDED 0x0008U /* Added to libpng-1.6.0 */
+ /* 0x0010U unused */
+ /* 0x0020U unused */
+#define PNG_FLAG_ROW_INIT 0x0040U
+#define PNG_FLAG_FILLER_AFTER 0x0080U
+#define PNG_FLAG_CRC_ANCILLARY_USE 0x0100U
+#define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200U
+#define PNG_FLAG_CRC_CRITICAL_USE 0x0400U
+#define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800U
+/* PNG_FLAG_ASSUME_sRGB unused 0x1000U * Added to libpng-1.5.4 */
+#define PNG_FLAG_OPTIMIZE_ALPHA 0x2000U /* Added to libpng-1.5.4 */
+#define PNG_FLAG_DETECT_UNINITIALIZED 0x4000U /* Added to libpng-1.5.4 */
+/* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000U */
+/* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000U */
+#define PNG_FLAG_LIBRARY_MISMATCH 0x20000U
+#define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000U
+#define PNG_FLAG_STRIP_ERROR_TEXT 0x80000U
+#define PNG_FLAG_BENIGN_ERRORS_WARN 0x100000U /* Added to libpng-1.4.0 */
+#define PNG_FLAG_APP_WARNINGS_WARN 0x200000U /* Added to libpng-1.6.0 */
+#define PNG_FLAG_APP_ERRORS_WARN 0x400000U /* Added to libpng-1.6.0 */
+ /* 0x800000U unused */
+ /* 0x1000000U unused */
+ /* 0x2000000U unused */
+ /* 0x4000000U unused */
+ /* 0x8000000U unused */
+ /* 0x10000000U unused */
+ /* 0x20000000U unused */
+ /* 0x40000000U unused */
+
+#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
+ PNG_FLAG_CRC_ANCILLARY_NOWARN)
+
+#define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \
+ PNG_FLAG_CRC_CRITICAL_IGNORE)
+
+#define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \
+ PNG_FLAG_CRC_CRITICAL_MASK)
+
+/* Save typing and make code easier to understand */
+
+#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
+ abs((int)((c1).green) - (int)((c2).green)) + \
+ abs((int)((c1).blue) - (int)((c2).blue)))
+
+/* Added to libpng-1.6.0: scale a 16-bit value in the range 0..65535 to 0..255
+ * by dividing by 257 *with rounding*. This macro is exact for the given range.
+ * See the discourse in pngrtran.c png_do_scale_16_to_8. The values in the
+ * macro were established by experiment (modifying the added value). The macro
+ * has a second variant that takes a value already scaled by 255 and divides by
+ * 65535 - this has a maximum error of .502. Over the range 0..65535*65535 it
+ * only gives off-by-one errors and only for 0.5% (1 in 200) of the values.
+ */
+#define PNG_DIV65535(v24) (((v24) + 32895) >> 16)
+#define PNG_DIV257(v16) PNG_DIV65535((png_uint_32)(v16) * 255)
+
+/* Added to libpng-1.2.6 JB */
+#define PNG_ROWBYTES(pixel_bits, width) \
+ ((pixel_bits) >= 8 ? \
+ ((size_t)(width) * (((size_t)(pixel_bits)) >> 3)) : \
+ (( ((size_t)(width) * ((size_t)(pixel_bits))) + 7) >> 3) )
+
+/* This returns the number of trailing bits in the last byte of a row, 0 if the
+ * last byte is completely full of pixels. It is, in principle, (pixel_bits x
+ * width) % 8, but that would overflow for large 'width'. The second macro is
+ * the same except that it returns the number of unused bits in the last byte;
+ * (8-TRAILBITS), but 0 when TRAILBITS is 0.
+ *
+ * NOTE: these macros are intended to be self-evidently correct and never
+ * overflow on the assumption that pixel_bits is in the range 0..255. The
+ * arguments are evaluated only once and they can be signed (e.g. as a result of
+ * the integral promotions). The result of the expression always has type
+ * (png_uint_32), however the compiler always knows it is in the range 0..7.
+ */
+#define PNG_TRAILBITS(pixel_bits, width) \
+ (((pixel_bits) * ((width) % (png_uint_32)8)) % 8)
+
+#define PNG_PADBITS(pixel_bits, width) \
+ ((8 - PNG_TRAILBITS(pixel_bits, width)) % 8)
+
+/* PNG_OUT_OF_RANGE returns true if value is outside the range
+ * ideal-delta..ideal+delta. Each argument is evaluated twice.
+ * "ideal" and "delta" should be constants, normally simple
+ * integers, "value" a variable. Added to libpng-1.2.6 JB
+ */
+#define PNG_OUT_OF_RANGE(value, ideal, delta) \
+ ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
+
+/* Conversions between fixed and floating point, only defined if
+ * required (to make sure the code doesn't accidentally use float
+ * when it is supposedly disabled.)
+ */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+/* The floating point conversion can't overflow, though it can and
+ * does lose accuracy relative to the original fixed point value.
+ * In practice this doesn't matter because png_fixed_point only
+ * stores numbers with very low precision. The png_ptr and s
+ * arguments are unused by default but are there in case error
+ * checking becomes a requirement.
+ */
+#define png_float(png_ptr, fixed, s) (.00001 * (fixed))
+
+/* The fixed point conversion performs range checking and evaluates
+ * its argument multiple times, so must be used with care. The
+ * range checking uses the PNG specification values for a signed
+ * 32-bit fixed point value except that the values are deliberately
+ * rounded-to-zero to an integral value - 21474 (21474.83 is roughly
+ * (2^31-1) * 100000). 's' is a string that describes the value being
+ * converted.
+ *
+ * NOTE: this macro will raise a png_error if the range check fails,
+ * therefore it is normally only appropriate to use this on values
+ * that come from API calls or other sources where an out of range
+ * error indicates a programming error, not a data error!
+ *
+ * NOTE: by default this is off - the macro is not used - because the
+ * function call saves a lot of code.
+ */
+#ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
+#define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
+ ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
+#define png_fixed_ITU(png_ptr, fp, s) ((fp) <= 214748 && (fp) >= 0 ?\
+ ((png_uint_32)(10000 * (fp))) : (png_fixed_error(png_ptr, s),0))
+#endif
+/* else the corresponding function is defined below, inside the scope of the
+ * cplusplus test.
+ */
+#endif
+
+/* Constants for known chunk types. If you need to add a chunk, define the name
+ * here. For historical reasons these constants have the form png_; i.e.
+ * the prefix is lower case. Please use decimal values as the parameters to
+ * match the ISO PNG specification and to avoid relying on the C locale
+ * interpretation of character values.
+ *
+ * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
+ * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
+ * to be generated if required.
+ *
+ * PNG_32b correctly produces a value shifted by up to 24 bits, even on
+ * architectures where (int) is only 16 bits.
+ *
+ * 1.6.47: PNG_32b was made into a preprocessor evaluable macro by replacing the
+ * static_cast with a promoting binary operation using a guaranteed 32-bit
+ * (minimum) unsigned value.
+ */
+#define PNG_32b(b,s) (((0xFFFFFFFFU)&(b)) << (s))
+#define PNG_U32(b1,b2,b3,b4) \
+ (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
+
+/* Chunk name validation. When using these macros all the arguments should be
+ * constants, otherwise code bloat may well occur. The macros are provided
+ * primarily for use in #if checks.
+ *
+ * PNG_32to8 produces a byte value with the right shift; used to extract the
+ * byte value from a chunk name.
+ */
+#define PNG_32to8(cn,s) (((cn) >> (s)) & 0xffU)
+#define PNG_CN_VALID_UPPER(b) ((b) >= 65 && (b) <= 90) /* upper-case ASCII */
+#define PNG_CN_VALID_ASCII(b) PNG_CN_VALID_UPPER((b) & ~32U)
+#define PNG_CHUNK_NAME_VALID(cn) (\
+ PNG_CN_VALID_ASCII(PNG_32to8(cn,24)) && /* critical, !ancillary */\
+ PNG_CN_VALID_ASCII(PNG_32to8(cn,16)) && /* public, !privately defined */\
+ PNG_CN_VALID_UPPER(PNG_32to8(cn, 8)) && /* VALID, !reserved */\
+ PNG_CN_VALID_ASCII(PNG_32to8(cn, 0)) /* data-dependent, !copy ok */)
+
+/* Constants for known chunk types.
+ *
+ * MAINTAINERS: If you need to add a chunk, define the name here.
+ * For historical reasons these constants have the form png_; i.e.
+ * the prefix is lower case. Please use decimal values as the parameters to
+ * match the ISO PNG specification and to avoid relying on the C locale
+ * interpretation of character values. Please keep the list sorted.
+ *
+ * Notice that PNG_U32 is used to define a 32-bit value for the 4 byte chunk
+ * type. In fact the specification does not express chunk types this way,
+ * however using a 32-bit value means that the chunk type can be read from the
+ * stream using exactly the same code as used for a 32-bit unsigned value and
+ * can be examined far more efficiently (using one arithmetic compare).
+ *
+ * Prior to 1.5.6 the chunk type constants were expressed as C strings. The
+ * libpng API still uses strings for 'unknown' chunks and a macro,
+ * PNG_STRING_FROM_CHUNK, allows a string to be generated if required. Notice
+ * that for portable code numeric values must still be used; the string "IHDR"
+ * is not portable and neither is PNG_U32('I', 'H', 'D', 'R').
+ *
+ * In 1.7.0 the definitions will be made public in png.h to avoid having to
+ * duplicate the same definitions in application code.
+ */
+#define png_IDAT PNG_U32( 73, 68, 65, 84)
+#define png_IEND PNG_U32( 73, 69, 78, 68)
+#define png_IHDR PNG_U32( 73, 72, 68, 82)
+#define png_PLTE PNG_U32( 80, 76, 84, 69)
+#define png_acTL PNG_U32( 97, 99, 84, 76) /* PNGv3: APNG */
+#define png_bKGD PNG_U32( 98, 75, 71, 68)
+#define png_cHRM PNG_U32( 99, 72, 82, 77)
+#define png_cICP PNG_U32( 99, 73, 67, 80) /* PNGv3 */
+#define png_cLLI PNG_U32( 99, 76, 76, 73) /* PNGv3 */
+#define png_eXIf PNG_U32(101, 88, 73, 102) /* registered July 2017 */
+#define png_fcTL PNG_U32(102, 99, 84, 76) /* PNGv3: APNG */
+#define png_fdAT PNG_U32(102, 100, 65, 84) /* PNGv3: APNG */
+#define png_fRAc PNG_U32(102, 82, 65, 99) /* registered, not defined */
+#define png_gAMA PNG_U32(103, 65, 77, 65)
+#define png_gIFg PNG_U32(103, 73, 70, 103)
+#define png_gIFt PNG_U32(103, 73, 70, 116) /* deprecated */
+#define png_gIFx PNG_U32(103, 73, 70, 120)
+#define png_hIST PNG_U32(104, 73, 83, 84)
+#define png_iCCP PNG_U32(105, 67, 67, 80)
+#define png_iTXt PNG_U32(105, 84, 88, 116)
+#define png_mDCV PNG_U32(109, 68, 67, 86) /* PNGv3 */
+#define png_oFFs PNG_U32(111, 70, 70, 115)
+#define png_pCAL PNG_U32(112, 67, 65, 76)
+#define png_pHYs PNG_U32(112, 72, 89, 115)
+#define png_sBIT PNG_U32(115, 66, 73, 84)
+#define png_sCAL PNG_U32(115, 67, 65, 76)
+#define png_sPLT PNG_U32(115, 80, 76, 84)
+#define png_sRGB PNG_U32(115, 82, 71, 66)
+#define png_sTER PNG_U32(115, 84, 69, 82)
+#define png_tEXt PNG_U32(116, 69, 88, 116)
+#define png_tIME PNG_U32(116, 73, 77, 69)
+#define png_tRNS PNG_U32(116, 82, 78, 83)
+#define png_zTXt PNG_U32(122, 84, 88, 116)
+
+/* The following will work on (signed char*) strings, whereas the get_uint_32
+ * macro will fail on top-bit-set values because of the sign extension.
+ */
+#define PNG_CHUNK_FROM_STRING(s)\
+ PNG_U32(0xff & (s)[0], 0xff & (s)[1], 0xff & (s)[2], 0xff & (s)[3])
+
+/* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
+ * signed and the argument is a (char[]) This macro will fail miserably on
+ * systems where (char) is more than 8 bits.
+ */
+#define PNG_STRING_FROM_CHUNK(s,c)\
+ (void)(((char*)(s))[0]=(char)(((c)>>24) & 0xff), \
+ ((char*)(s))[1]=(char)(((c)>>16) & 0xff),\
+ ((char*)(s))[2]=(char)(((c)>>8) & 0xff), \
+ ((char*)(s))[3]=(char)((c & 0xff)))
+
+/* Do the same but terminate with a null character. */
+#define PNG_CSTRING_FROM_CHUNK(s,c)\
+ (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
+
+/* Test on flag values as defined in the spec (section 5.4): */
+#define PNG_CHUNK_ANCILLARY(c) (1 & ((c) >> 29))
+#define PNG_CHUNK_CRITICAL(c) (!PNG_CHUNK_ANCILLARY(c))
+#define PNG_CHUNK_PRIVATE(c) (1 & ((c) >> 21))
+#define PNG_CHUNK_RESERVED(c) (1 & ((c) >> 13))
+#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >> 5))
+
+/* Known chunks. All supported chunks must be listed here. The macro PNG_CHUNK
+ * contains the four character ASCII name by which the chunk is identified. The
+ * macro is implemented as required to build tables or switch statements which
+ * require entries for every known chunk. The macro also contains an index
+ * value which should be in order (this is checked in png.c).
+ *
+ * Notice that "known" does not require "SUPPORTED"; tables should be built in
+ * such a way that chunks unsupported in a build require no more than the table
+ * entry (which should be small.) In particular function pointers for
+ * unsupported chunks should be NULL.
+ *
+ * At present these index values are not exported (not part of the public API)
+ * so can be changed at will. For convenience the names are in lexical sort
+ * order but with the critical chunks at the start in the order of occurence in
+ * a PNG.
+ *
+ * PNG_INFO_ values do not exist for every one of these chunk handles; for
+ * example PNG_INFO_{IDAT,IEND,tEXt,iTXt,zTXt} and possibly other chunks in the
+ * future.
+ */
+#define PNG_KNOWN_CHUNKS\
+ PNG_CHUNK(IHDR, 0)\
+ PNG_CHUNK(PLTE, 1)\
+ PNG_CHUNK(IDAT, 2)\
+ PNG_CHUNK(IEND, 3)\
+ PNG_CHUNK(acTL, 4)\
+ PNG_CHUNK(bKGD, 5)\
+ PNG_CHUNK(cHRM, 6)\
+ PNG_CHUNK(cICP, 7)\
+ PNG_CHUNK(cLLI, 8)\
+ PNG_CHUNK(eXIf, 9)\
+ PNG_CHUNK(fcTL, 10)\
+ PNG_CHUNK(fdAT, 11)\
+ PNG_CHUNK(gAMA, 12)\
+ PNG_CHUNK(hIST, 13)\
+ PNG_CHUNK(iCCP, 14)\
+ PNG_CHUNK(iTXt, 15)\
+ PNG_CHUNK(mDCV, 16)\
+ PNG_CHUNK(oFFs, 17)\
+ PNG_CHUNK(pCAL, 18)\
+ PNG_CHUNK(pHYs, 19)\
+ PNG_CHUNK(sBIT, 20)\
+ PNG_CHUNK(sCAL, 21)\
+ PNG_CHUNK(sPLT, 22)\
+ PNG_CHUNK(sRGB, 23)\
+ PNG_CHUNK(tEXt, 24)\
+ PNG_CHUNK(tIME, 25)\
+ PNG_CHUNK(tRNS, 26)\
+ PNG_CHUNK(zTXt, 27)
+
+/* Gamma values (new at libpng-1.5.4): */
+#define PNG_GAMMA_MAC_OLD 151724 /* Assume '1.8' is really 2.2/1.45! */
+#define PNG_GAMMA_MAC_INVERSE 65909
+#define PNG_GAMMA_sRGB_INVERSE 45455
+
+/* gamma sanity check. libpng cannot implement gamma transforms outside a
+ * certain limit because of its use of 16-bit fixed point intermediate values.
+ * Gamma values that are too large or too small will zap the 16-bit values all
+ * to 0 or 65535 resulting in an obvious 'bad' image.
+ *
+ * In libpng 1.6.0 the limits were changed from 0.07..3 to 0.01..100 to
+ * accommodate the optimal 16-bit gamma of 36 and its reciprocal.
+ *
+ * These are png_fixed_point integral values:
+ */
+#define PNG_LIB_GAMMA_MIN 1000
+#define PNG_LIB_GAMMA_MAX 10000000
+
+/* Almost everything below is C specific; the #defines above can be used in
+ * non-C code (so long as it is C-preprocessed) the rest of this stuff cannot.
+ */
+#ifndef PNG_VERSION_INFO_ONLY
+
+#include "pngstruct.h"
+#include "pnginfo.h"
+
+/* Validate the include paths - the include path used to generate pnglibconf.h
+ * must match that used in the build, or we must be using pnglibconf.h.prebuilt:
+ */
+#if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM
+# error The include path of is incorrect
+ /* When pnglibconf.h was built, the copy of zlib.h that it used was not the
+ * same as the one being used here. Considering how libpng makes decisions
+ * to use the zlib API based on the zlib version number, the -I options must
+ * match.
+ *
+ * A possible cause of this mismatch is that you passed an -I option in
+ * CFLAGS, which is unlikely to work. All the preprocessor options, and all
+ * the -I options in particular, should be in CPPFLAGS.
+ */
+#endif
+
+/* This is used for 16-bit gamma tables -- only the top level pointers are
+ * const; this could be changed:
+ */
+typedef const png_uint_16p * png_const_uint_16pp;
+
+/* Added to libpng-1.5.7: sRGB conversion tables */
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
+ defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
+PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_table, [256]);
+ /* Convert from an sRGB encoded value 0..255 to a 16-bit linear value,
+ * 0..65535. This table gives the closest 16-bit answers (no errors).
+ */
+#endif
+
+PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_base, [512]);
+PNG_INTERNAL_DATA(const png_byte, png_sRGB_delta, [512]);
+
+#define PNG_sRGB_FROM_LINEAR(linear) \
+ ((png_byte)(0xff & ((png_sRGB_base[(linear)>>15] \
+ + ((((linear) & 0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8)))
+ /* Given a value 'linear' in the range 0..255*65535 calculate the 8-bit sRGB
+ * encoded value with maximum error 0.646365. Note that the input is not a
+ * 16-bit value; it has been multiplied by 255! */
+#endif /* SIMPLIFIED_READ/WRITE */
+
+
+/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+/* Internal functions; these are not exported from a DLL however because they
+ * are used within several of the C source files they have to be C extern.
+ *
+ * All of these functions must be declared with PNG_INTERNAL_FUNCTION.
+ */
+/* Zlib support */
+#define PNG_UNEXPECTED_ZLIB_RETURN (-7)
+PNG_INTERNAL_FUNCTION(void, png_zstream_error,(png_structrp png_ptr, int ret),
+ PNG_EMPTY);
+ /* Used by the zlib handling functions to ensure that z_stream::msg is always
+ * set before they return.
+ */
+
+#ifdef PNG_WRITE_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_free_buffer_list,(png_structrp png_ptr,
+ png_compression_bufferp *list),PNG_EMPTY);
+ /* Free the buffer list used by the compressed write code. */
+#endif
+
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
+ !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
+ (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \
+ defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+ defined(PNG_mDCV_SUPPORTED) || \
+ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \
+ (defined(PNG_sCAL_SUPPORTED) && \
+ defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
+PNG_INTERNAL_FUNCTION(png_fixed_point,png_fixed,(png_const_structrp png_ptr,
+ double fp, png_const_charp text),PNG_EMPTY);
+#endif
+
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
+ !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
+ (defined(PNG_cLLI_SUPPORTED) || defined(PNG_mDCV_SUPPORTED))
+PNG_INTERNAL_FUNCTION(png_uint_32,png_fixed_ITU,(png_const_structrp png_ptr,
+ double fp, png_const_charp text),PNG_EMPTY);
+#endif
+
+/* Check the user version string for compatibility, returns false if the version
+ * numbers aren't compatible.
+ */
+PNG_INTERNAL_FUNCTION(int,png_user_version_check,(png_structrp png_ptr,
+ png_const_charp user_png_ver),PNG_EMPTY);
+
+#ifdef PNG_READ_SUPPORTED /* should only be used on read */
+/* Security: read limits on the largest allocations while reading a PNG. This
+ * avoids very large allocations caused by PNG files with damaged or altered
+ * chunk 'length' fields.
+ */
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED /* run-time limit */
+# define png_chunk_max(png_ptr) ((png_ptr)->user_chunk_malloc_max)
+
+#elif PNG_USER_CHUNK_MALLOC_MAX > 0 /* compile-time limit */
+# define png_chunk_max(png_ptr) ((void)png_ptr, PNG_USER_CHUNK_MALLOC_MAX)
+
+#elif (defined PNG_MAX_MALLOC_64K) /* legacy system limit */
+# define png_chunk_max(png_ptr) ((void)png_ptr, 65536U)
+
+#else /* modern system limit SIZE_MAX (C99) */
+# define png_chunk_max(png_ptr) ((void)png_ptr, PNG_SIZE_MAX)
+#endif
+#endif /* READ */
+
+/* Internal base allocator - no messages, NULL on failure to allocate. This
+ * does, however, call the application provided allocator and that could call
+ * png_error (although that would be a bug in the application implementation.)
+ */
+PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_base,(png_const_structrp png_ptr,
+ png_alloc_size_t size),PNG_ALLOCATED);
+
+#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
+ defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
+/* Internal array allocator, outputs no error or warning messages on failure,
+ * just returns NULL.
+ */
+PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_array,(png_const_structrp png_ptr,
+ int nelements, size_t element_size),PNG_ALLOCATED);
+
+/* The same but an existing array is extended by add_elements. This function
+ * also memsets the new elements to 0 and copies the old elements. The old
+ * array is not freed or altered.
+ */
+PNG_INTERNAL_FUNCTION(png_voidp,png_realloc_array,(png_const_structrp png_ptr,
+ png_const_voidp array, int old_elements, int add_elements,
+ size_t element_size),PNG_ALLOCATED);
+#endif /* text, sPLT or unknown chunks */
+
+/* Magic to create a struct when there is no struct to call the user supplied
+ * memory allocators. Because error handling has not been set up the memory
+ * handlers can't safely call png_error, but this is an obscure and undocumented
+ * restriction so libpng has to assume that the 'free' handler, at least, might
+ * call png_error.
+ */
+PNG_INTERNAL_FUNCTION(png_structp,png_create_png_struct,
+ (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
+ png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn,
+ png_free_ptr free_fn),PNG_ALLOCATED);
+
+/* Free memory from internal libpng struct */
+PNG_INTERNAL_FUNCTION(void,png_destroy_png_struct,(png_structrp png_ptr),
+ PNG_EMPTY);
+
+/* Free an allocated jmp_buf (always succeeds) */
+PNG_INTERNAL_FUNCTION(void,png_free_jmpbuf,(png_structrp png_ptr),PNG_EMPTY);
+
+/* Function to allocate memory for zlib. PNGAPI is disallowed. */
+PNG_INTERNAL_FUNCTION(voidpf,png_zalloc,(voidpf png_ptr, uInt items, uInt size),
+ PNG_ALLOCATED);
+
+/* Function to free memory for zlib. PNGAPI is disallowed. */
+PNG_INTERNAL_FUNCTION(void,png_zfree,(voidpf png_ptr, voidpf ptr),PNG_EMPTY);
+
+/* Next four functions are used internally as callbacks. PNGCBAPI is required
+ * but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3, changed to
+ * PNGCBAPI at 1.5.0
+ */
+
+PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_read_data,(png_structp png_ptr,
+ png_bytep data, size_t length),PNG_EMPTY);
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_push_fill_buffer,(png_structp png_ptr,
+ png_bytep buffer, size_t length),PNG_EMPTY);
+#endif
+
+PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_write_data,(png_structp png_ptr,
+ png_bytep data, size_t length),PNG_EMPTY);
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+# ifdef PNG_STDIO_SUPPORTED
+PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_flush,(png_structp png_ptr),
+ PNG_EMPTY);
+# endif
+#endif
+
+/* Reset the CRC variable */
+PNG_INTERNAL_FUNCTION(void,png_reset_crc,(png_structrp png_ptr),PNG_EMPTY);
+
+/* Write the "data" buffer to whatever output you are using */
+PNG_INTERNAL_FUNCTION(void,png_write_data,(png_structrp png_ptr,
+ png_const_bytep data, size_t length),PNG_EMPTY);
+
+/* Read and check the PNG file signature */
+PNG_INTERNAL_FUNCTION(void,png_read_sig,(png_structrp png_ptr,
+ png_inforp info_ptr),PNG_EMPTY);
+
+/* Read the chunk header (length + type name) */
+PNG_INTERNAL_FUNCTION(png_uint_32,png_read_chunk_header,(png_structrp png_ptr),
+ PNG_EMPTY);
+
+/* Read data from whatever input you are using into the "data" buffer */
+PNG_INTERNAL_FUNCTION(void,png_read_data,(png_structrp png_ptr, png_bytep data,
+ size_t length),PNG_EMPTY);
+
+/* Read bytes into buf, and update png_ptr->crc */
+PNG_INTERNAL_FUNCTION(void,png_crc_read,(png_structrp png_ptr, png_bytep buf,
+ png_uint_32 length),PNG_EMPTY);
+
+/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
+PNG_INTERNAL_FUNCTION(int,png_crc_finish,(png_structrp png_ptr,
+ png_uint_32 skip),PNG_EMPTY);
+
+/* Calculate the CRC over a section of data. Note that we are only
+ * passing a maximum of 64K on systems that have this as a memory limit,
+ * since this is the maximum buffer size we can specify.
+ */
+PNG_INTERNAL_FUNCTION(void,png_calculate_crc,(png_structrp png_ptr,
+ png_const_bytep ptr, size_t length),PNG_EMPTY);
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_flush,(png_structrp png_ptr),PNG_EMPTY);
+#endif
+
+/* Write various chunks */
+
+/* Write the IHDR chunk, and update the png_struct with the necessary
+ * information.
+ */
+PNG_INTERNAL_FUNCTION(void,png_write_IHDR,(png_structrp png_ptr,
+ png_uint_32 width, png_uint_32 height, int bit_depth, int color_type,
+ int compression_method, int filter_method, int interlace_method),PNG_EMPTY);
+
+PNG_INTERNAL_FUNCTION(void,png_write_PLTE,(png_structrp png_ptr,
+ png_const_colorp palette, png_uint_32 num_pal),PNG_EMPTY);
+
+PNG_INTERNAL_FUNCTION(void,png_compress_IDAT,(png_structrp png_ptr,
+ png_const_bytep row_data, png_alloc_size_t row_data_length, int flush),
+ PNG_EMPTY);
+
+PNG_INTERNAL_FUNCTION(void,png_write_IEND,(png_structrp png_ptr),PNG_EMPTY);
+
+#ifdef PNG_WRITE_gAMA_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_gAMA_fixed,(png_structrp png_ptr,
+ png_fixed_point file_gamma),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_sBIT_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_sBIT,(png_structrp png_ptr,
+ png_const_color_8p sbit, int color_type),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_cHRM_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_cHRM_fixed,(png_structrp png_ptr,
+ const png_xy *xy), PNG_EMPTY);
+ /* The xy value must have been previously validated */
+#endif
+
+#ifdef PNG_WRITE_cICP_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_cICP,(png_structrp png_ptr,
+ png_byte colour_primaries, png_byte transfer_function,
+ png_byte matrix_coefficients, png_byte video_full_range_flag), PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_cLLI_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_cLLI_fixed,(png_structrp png_ptr,
+ png_uint_32 maxCLL, png_uint_32 maxFALL), PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_mDCV_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_mDCV_fixed,(png_structrp png_ptr,
+ png_uint_16 red_x, png_uint_16 red_y,
+ png_uint_16 green_x, png_uint_16 green_y,
+ png_uint_16 blue_x, png_uint_16 blue_y,
+ png_uint_16 white_x, png_uint_16 white_y,
+ png_uint_32 maxDL, png_uint_32 minDL), PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_sRGB_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_sRGB,(png_structrp png_ptr,
+ int intent),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_eXIf_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_eXIf,(png_structrp png_ptr,
+ png_bytep exif, int num_exif),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_iCCP_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_iCCP,(png_structrp png_ptr,
+ png_const_charp name, png_const_bytep profile, png_uint_32 proflen),
+ PNG_EMPTY);
+ /* Writes a previously 'set' profile. The profile argument is **not**
+ * compressed.
+ */
+#endif
+
+#ifdef PNG_WRITE_sPLT_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_sPLT,(png_structrp png_ptr,
+ png_const_sPLT_tp palette),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_tRNS_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_tRNS,(png_structrp png_ptr,
+ png_const_bytep trans, png_const_color_16p values, int number,
+ int color_type),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_bKGD_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_bKGD,(png_structrp png_ptr,
+ png_const_color_16p values, int color_type),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_hIST_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_hIST,(png_structrp png_ptr,
+ png_const_uint_16p hist, int num_hist),PNG_EMPTY);
+#endif
+
+/* Chunks that have keywords */
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr,
+ png_const_charp key, png_const_charp text, size_t text_len),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp
+ key, png_const_charp text, int compression),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_iTXt,(png_structrp png_ptr,
+ int compression, png_const_charp key, png_const_charp lang,
+ png_const_charp lang_key, png_const_charp text),PNG_EMPTY);
+#endif
+
+#ifdef PNG_TEXT_SUPPORTED /* Added at version 1.0.14 and 1.2.4 */
+PNG_INTERNAL_FUNCTION(int,png_set_text_2,(png_const_structrp png_ptr,
+ png_inforp info_ptr, png_const_textp text_ptr, int num_text),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_oFFs_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_oFFs,(png_structrp png_ptr,
+ png_int_32 x_offset, png_int_32 y_offset, int unit_type),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_pCAL_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_pCAL,(png_structrp png_ptr,
+ png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams,
+ png_const_charp units, png_charpp params),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_pHYs_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_pHYs,(png_structrp png_ptr,
+ png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
+ int unit_type),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_tIME_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_tIME,(png_structrp png_ptr,
+ png_const_timep mod_time),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_sCAL_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_sCAL_s,(png_structrp png_ptr,
+ int unit, png_const_charp width, png_const_charp height),PNG_EMPTY);
+#endif
+
+/* Called when finished processing a row of data */
+PNG_INTERNAL_FUNCTION(void,png_write_finish_row,(png_structrp png_ptr),
+ PNG_EMPTY);
+
+/* Internal use only. Called before first row of data */
+PNG_INTERNAL_FUNCTION(void,png_write_start_row,(png_structrp png_ptr),
+ PNG_EMPTY);
+
+/* Combine a row of data, dealing with alpha, etc. if requested. 'row' is an
+ * array of png_ptr->width pixels. If the image is not interlaced or this
+ * is the final pass this just does a memcpy, otherwise the "display" flag
+ * is used to determine whether to copy pixels that are not in the current pass.
+ *
+ * Because 'png_do_read_interlace' (below) replicates pixels this allows this
+ * function to achieve the documented 'blocky' appearance during interlaced read
+ * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
+ * are not changed if they are not in the current pass, when display is 0.
+ *
+ * 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
+ *
+ * The API always reads from the png_struct row buffer and always assumes that
+ * it is full width (png_do_read_interlace has already been called.)
+ *
+ * This function is only ever used to write to row buffers provided by the
+ * caller of the relevant libpng API and the row must have already been
+ * transformed by the read transformations.
+ *
+ * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
+ * bitmasks for use within the code, otherwise runtime generated masks are used.
+ * The default is compile time masks.
+ */
+#ifndef PNG_USE_COMPILE_TIME_MASKS
+# define PNG_USE_COMPILE_TIME_MASKS 1
+#endif
+PNG_INTERNAL_FUNCTION(void,png_combine_row,(png_const_structrp png_ptr,
+ png_bytep row, int display),PNG_EMPTY);
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+/* Expand an interlaced row: the 'row_info' describes the pass data that has
+ * been read in and must correspond to the pixels in 'row', the pixels are
+ * expanded (moved apart) in 'row' to match the final layout, when doing this
+ * the pixels are *replicated* to the intervening space. This is essential for
+ * the correct operation of png_combine_row, above.
+ */
+PNG_INTERNAL_FUNCTION(void,png_do_read_interlace,(png_row_infop row_info,
+ png_bytep row, int pass, png_uint_32 transformations),PNG_EMPTY);
+#endif
+
+/* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+/* Grab pixels out of a row for an interlaced pass */
+PNG_INTERNAL_FUNCTION(void,png_do_write_interlace,(png_row_infop row_info,
+ png_bytep row, int pass),PNG_EMPTY);
+#endif
+
+/* Unfilter a row: check the filter value before calling this, there is no point
+ * calling it for PNG_FILTER_VALUE_NONE.
+ */
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY);
+
+#if PNG_ARM_NEON_OPT > 0
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,(png_row_infop row_info,
+ png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+#endif
+
+#if PNG_MIPS_MSA_IMPLEMENTATION == 1
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_msa,(png_row_infop row_info,
+ png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_msa,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_msa,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_msa,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_msa,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_msa,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_msa,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+#endif
+
+#if PNG_MIPS_MMI_IMPLEMENTATION > 0
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_mmi,(png_row_infop row_info,
+ png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_mmi,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_mmi,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_mmi,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_mmi,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_mmi,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_mmi,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+#endif
+
+#if PNG_POWERPC_VSX_OPT > 0
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_vsx,(png_row_infop row_info,
+ png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_vsx,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_vsx,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_vsx,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_vsx,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_vsx,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_vsx,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+#endif
+
+#if PNG_INTEL_SSE_IMPLEMENTATION > 0
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_sse2,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_sse2,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_sse2,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_sse2,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_sse2,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_sse2,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+#endif
+
+#if PNG_LOONGARCH_LSX_IMPLEMENTATION == 1
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_lsx,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_lsx,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_lsx,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_lsx,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_lsx,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_lsx,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_lsx,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+#endif
+
+#if PNG_RISCV_RVV_OPT > 0
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_rvv,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_rvv,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_rvv,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_rvv,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_rvv,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_rvv,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_rvv,(png_row_infop
+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+#endif
+
+/* Choose the best filter to use and filter the row data */
+PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr,
+ png_row_infop row_info),PNG_EMPTY);
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr,
+ png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY);
+ /* Read 'avail_out' bytes of data from the IDAT stream. If the output buffer
+ * is NULL the function checks, instead, for the end of the stream. In this
+ * case a benign error will be issued if the stream end is not found or if
+ * extra data has to be consumed.
+ */
+PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT,(png_structrp png_ptr),
+ PNG_EMPTY);
+ /* This cleans up when the IDAT LZ stream does not end when the last image
+ * byte is read; there is still some pending input.
+ */
+
+PNG_INTERNAL_FUNCTION(void,png_read_finish_row,(png_structrp png_ptr),
+ PNG_EMPTY);
+ /* Finish a row while reading, dealing with interlacing passes, etc. */
+#endif /* SEQUENTIAL_READ */
+
+/* Initialize the row buffers, etc. */
+PNG_INTERNAL_FUNCTION(void,png_read_start_row,(png_structrp png_ptr),PNG_EMPTY);
+
+#if ZLIB_VERNUM >= 0x1240
+PNG_INTERNAL_FUNCTION(int,png_zlib_inflate,(png_structrp png_ptr, int flush),
+ PNG_EMPTY);
+# define PNG_INFLATE(pp, flush) png_zlib_inflate(pp, flush)
+#else /* Zlib < 1.2.4 */
+# define PNG_INFLATE(pp, flush) inflate(&(pp)->zstream, flush)
+#endif /* Zlib < 1.2.4 */
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+/* Optional call to update the users info structure */
+PNG_INTERNAL_FUNCTION(void,png_read_transform_info,(png_structrp png_ptr,
+ png_inforp info_ptr),PNG_EMPTY);
+#endif
+
+/* Shared transform functions, defined in pngtran.c */
+#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
+ defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_do_strip_channel,(png_row_infop row_info,
+ png_bytep row, int at_start),PNG_EMPTY);
+#endif
+
+#ifdef PNG_16BIT_SUPPORTED
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_do_swap,(png_row_infop row_info,
+ png_bytep row),PNG_EMPTY);
+#endif
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
+ defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_do_packswap,(png_row_infop row_info,
+ png_bytep row),PNG_EMPTY);
+#endif
+
+#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_do_invert,(png_row_infop row_info,
+ png_bytep row),PNG_EMPTY);
+#endif
+
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_do_bgr,(png_row_infop row_info,
+ png_bytep row),PNG_EMPTY);
+#endif
+
+/* The following decodes the appropriate chunks, and does error correction,
+ * then calls the appropriate callback for the chunk if it is valid.
+ */
+typedef enum
+{
+ /* Result of a call to png_handle_chunk made to handle the current chunk
+ * png_struct::chunk_name on read. Always informational, either the stream
+ * is read for the next chunk or the routine will call png_error.
+ *
+ * NOTE: order is important internally. handled_saved and above are regarded
+ * as handling the chunk.
+ */
+ handled_error = 0, /* bad crc or known and bad format or too long */
+ handled_discarded, /* not saved in the unknown chunk list */
+ handled_saved, /* saved in the unknown chunk list */
+ handled_ok /* known, supported and handled without error */
+} png_handle_result_code;
+
+PNG_INTERNAL_FUNCTION(png_handle_result_code,png_handle_unknown,
+ (png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length, int keep),
+ PNG_EMPTY);
+ /* This is the function that gets called for unknown chunks. The 'keep'
+ * argument is either non-zero for a known chunk that has been set to be
+ * handled as unknown or zero for an unknown chunk. By default the function
+ * just skips the chunk or errors out if it is critical.
+ */
+
+PNG_INTERNAL_FUNCTION(png_handle_result_code,png_handle_chunk,
+ (png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+ /* This handles the current chunk png_ptr->chunk_name with unread
+ * data[length] and returns one of the above result codes.
+ */
+
+#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\
+ defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
+PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling,
+ (png_const_structrp png_ptr, png_uint_32 chunk_name),PNG_EMPTY);
+ /* Exactly as the API png_handle_as_unknown() except that the argument is a
+ * 32-bit chunk name, not a string.
+ */
+#endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */
+
+/* Handle the transformations for reading and writing */
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_do_read_transformations,(png_structrp png_ptr,
+ png_row_infop row_info),PNG_EMPTY);
+#endif
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_do_write_transformations,(png_structrp png_ptr,
+ png_row_infop row_info),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_init_read_transformations,(png_structrp png_ptr),
+ PNG_EMPTY);
+#endif
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_push_read_chunk,(png_structrp png_ptr,
+ png_inforp info_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_read_sig,(png_structrp png_ptr,
+ png_inforp info_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_check_crc,(png_structrp png_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_save_buffer,(png_structrp png_ptr),
+ PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_restore_buffer,(png_structrp png_ptr,
+ png_bytep buffer, size_t buffer_length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_read_IDAT,(png_structrp png_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_process_IDAT_data,(png_structrp png_ptr,
+ png_bytep buffer, size_t buffer_length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_process_row,(png_structrp png_ptr),
+ PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_have_info,(png_structrp png_ptr,
+ png_inforp info_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_have_end,(png_structrp png_ptr,
+ png_inforp info_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_have_row,(png_structrp png_ptr,
+ png_bytep row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_read_end,(png_structrp png_ptr,
+ png_inforp info_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_process_some_data,(png_structrp png_ptr,
+ png_inforp info_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row,(png_structrp png_ptr),
+ PNG_EMPTY);
+#endif /* PROGRESSIVE_READ */
+
+#ifdef PNG_iCCP_SUPPORTED
+/* Routines for checking parts of an ICC profile. */
+#ifdef PNG_READ_iCCP_SUPPORTED
+PNG_INTERNAL_FUNCTION(int,png_icc_check_length,(png_const_structrp png_ptr,
+ png_const_charp name, png_uint_32 profile_length), PNG_EMPTY);
+#endif /* READ_iCCP */
+PNG_INTERNAL_FUNCTION(int,png_icc_check_header,(png_const_structrp png_ptr,
+ png_const_charp name, png_uint_32 profile_length,
+ png_const_bytep profile /* first 132 bytes only */, int color_type),
+ PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(int,png_icc_check_tag_table,(png_const_structrp png_ptr,
+ png_const_charp name, png_uint_32 profile_length,
+ png_const_bytep profile /* header plus whole tag table */), PNG_EMPTY);
+#endif /* iCCP */
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_set_rgb_coefficients, (png_structrp png_ptr),
+ PNG_EMPTY);
+ /* Set the rgb_to_gray coefficients from the cHRM Y values (if unset) */
+#endif /* READ_RGB_TO_GRAY */
+
+/* Added at libpng version 1.4.0 */
+PNG_INTERNAL_FUNCTION(void,png_check_IHDR,(png_const_structrp png_ptr,
+ png_uint_32 width, png_uint_32 height, int bit_depth,
+ int color_type, int interlace_type, int compression_type,
+ int filter_type),PNG_EMPTY);
+
+/* Added at libpng version 1.5.10 */
+#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
+ defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_do_check_palette_indexes,
+ (png_structrp png_ptr, png_row_infop row_info),PNG_EMPTY);
+#endif
+
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_fixed_error,(png_const_structrp png_ptr,
+ png_const_charp name),PNG_NORETURN);
+#endif
+
+/* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
+ * the end. Always leaves the buffer nul terminated. Never errors out (and
+ * there is no error code.)
+ */
+PNG_INTERNAL_FUNCTION(size_t,png_safecat,(png_charp buffer, size_t bufsize,
+ size_t pos, png_const_charp string),PNG_EMPTY);
+
+/* Various internal functions to handle formatted warning messages, currently
+ * only implemented for warnings.
+ */
+#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
+/* Utility to dump an unsigned value into a buffer, given a start pointer and
+ * and end pointer (which should point just *beyond* the end of the buffer!)
+ * Returns the pointer to the start of the formatted string. This utility only
+ * does unsigned values.
+ */
+PNG_INTERNAL_FUNCTION(png_charp,png_format_number,(png_const_charp start,
+ png_charp end, int format, png_alloc_size_t number),PNG_EMPTY);
+
+/* Convenience macro that takes an array: */
+#define PNG_FORMAT_NUMBER(buffer,format,number) \
+ png_format_number(buffer, buffer + (sizeof buffer), format, number)
+
+/* Suggested size for a number buffer (enough for 64 bits and a sign!) */
+#define PNG_NUMBER_BUFFER_SIZE 24
+
+/* These are the integer formats currently supported, the name is formed from
+ * the standard printf(3) format string.
+ */
+#define PNG_NUMBER_FORMAT_u 1 /* chose unsigned API! */
+#define PNG_NUMBER_FORMAT_02u 2
+#define PNG_NUMBER_FORMAT_d 1 /* chose signed API! */
+#define PNG_NUMBER_FORMAT_02d 2
+#define PNG_NUMBER_FORMAT_x 3
+#define PNG_NUMBER_FORMAT_02x 4
+#define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
+#endif
+
+#ifdef PNG_WARNINGS_SUPPORTED
+/* New defines and members adding in libpng-1.5.4 */
+# define PNG_WARNING_PARAMETER_SIZE 32
+# define PNG_WARNING_PARAMETER_COUNT 8 /* Maximum 9; see pngerror.c */
+
+/* An l-value of this type has to be passed to the APIs below to cache the
+ * values of the parameters to a formatted warning message.
+ */
+typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
+ PNG_WARNING_PARAMETER_SIZE];
+
+PNG_INTERNAL_FUNCTION(void,png_warning_parameter,(png_warning_parameters p,
+ int number, png_const_charp string),PNG_EMPTY);
+ /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
+ * including the trailing '\0'.
+ */
+PNG_INTERNAL_FUNCTION(void,png_warning_parameter_unsigned,
+ (png_warning_parameters p, int number, int format, png_alloc_size_t value),
+ PNG_EMPTY);
+ /* Use png_alloc_size_t because it is an unsigned type as big as any we
+ * need to output. Use the following for a signed value.
+ */
+PNG_INTERNAL_FUNCTION(void,png_warning_parameter_signed,
+ (png_warning_parameters p, int number, int format, png_int_32 value),
+ PNG_EMPTY);
+
+PNG_INTERNAL_FUNCTION(void,png_formatted_warning,(png_const_structrp png_ptr,
+ png_warning_parameters p, png_const_charp message),PNG_EMPTY);
+ /* 'message' follows the X/Open approach of using @1, @2 to insert
+ * parameters previously supplied using the above functions. Errors in
+ * specifying the parameters will simply result in garbage substitutions.
+ */
+#endif
+
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+/* Application errors (new in 1.6); use these functions (declared below) for
+ * errors in the parameters or order of API function calls on read. The
+ * 'warning' should be used for an error that can be handled completely; the
+ * 'error' for one which can be handled safely but which may lose application
+ * information or settings.
+ *
+ * By default these both result in a png_error call prior to release, while in a
+ * released version the 'warning' is just a warning. However if the application
+ * explicitly disables benign errors (explicitly permitting the code to lose
+ * information) they both turn into warnings.
+ *
+ * If benign errors aren't supported they end up as the corresponding base call
+ * (png_warning or png_error.)
+ */
+PNG_INTERNAL_FUNCTION(void,png_app_warning,(png_const_structrp png_ptr,
+ png_const_charp message),PNG_EMPTY);
+ /* The application provided invalid parameters to an API function or called
+ * an API function at the wrong time, libpng can completely recover.
+ */
+
+PNG_INTERNAL_FUNCTION(void,png_app_error,(png_const_structrp png_ptr,
+ png_const_charp message),PNG_EMPTY);
+ /* As above but libpng will ignore the call, or attempt some other partial
+ * recovery from the error.
+ */
+#else
+# define png_app_warning(pp,s) png_warning(pp,s)
+# define png_app_error(pp,s) png_error(pp,s)
+#endif
+
+PNG_INTERNAL_FUNCTION(void,png_chunk_report,(png_const_structrp png_ptr,
+ png_const_charp message, int error),PNG_EMPTY);
+ /* Report a recoverable issue in chunk data. On read this is used to report
+ * a problem found while reading a particular chunk and the
+ * png_chunk_benign_error or png_chunk_warning function is used as
+ * appropriate. On write this is used to report an error that comes from
+ * data set via an application call to a png_set_ API and png_app_error or
+ * png_app_warning is used as appropriate.
+ *
+ * The 'error' parameter must have one of the following values:
+ */
+#define PNG_CHUNK_WARNING 0 /* never an error */
+#define PNG_CHUNK_WRITE_ERROR 1 /* an error only on write */
+#define PNG_CHUNK_ERROR 2 /* always an error */
+
+/* ASCII to FP interfaces, currently only implemented if sCAL
+ * support is required.
+ */
+#if defined(PNG_sCAL_SUPPORTED)
+/* MAX_DIGITS is actually the maximum number of characters in an sCAL
+ * width or height, derived from the precision (number of significant
+ * digits - a build time settable option) and assumptions about the
+ * maximum ridiculous exponent.
+ */
+#define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/)
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_ascii_from_fp,(png_const_structrp png_ptr,
+ png_charp ascii, size_t size, double fp, unsigned int precision),
+ PNG_EMPTY);
+#endif /* FLOATING_POINT */
+
+#ifdef PNG_FIXED_POINT_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr,
+ png_charp ascii, size_t size, png_fixed_point fp),PNG_EMPTY);
+#endif /* FIXED_POINT */
+#endif /* sCAL */
+
+#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
+/* An internal API to validate the format of a floating point number.
+ * The result is the index of the next character. If the number is
+ * not valid it will be the index of a character in the supposed number.
+ *
+ * The format of a number is defined in the PNG extensions specification
+ * and this API is strictly conformant to that spec, not anyone elses!
+ *
+ * The format as a regular expression is:
+ *
+ * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
+ *
+ * or:
+ *
+ * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
+ *
+ * The complexity is that either integer or fraction must be present and the
+ * fraction is permitted to have no digits only if the integer is present.
+ *
+ * NOTE: The dangling E problem.
+ * There is a PNG valid floating point number in the following:
+ *
+ * PNG floating point numbers are not greedy.
+ *
+ * Working this out requires *TWO* character lookahead (because of the
+ * sign), the parser does not do this - it will fail at the 'r' - this
+ * doesn't matter for PNG sCAL chunk values, but it requires more care
+ * if the value were ever to be embedded in something more complex. Use
+ * ANSI-C strtod if you need the lookahead.
+ */
+/* State table for the parser. */
+#define PNG_FP_INTEGER 0 /* before or in integer */
+#define PNG_FP_FRACTION 1 /* before or in fraction */
+#define PNG_FP_EXPONENT 2 /* before or in exponent */
+#define PNG_FP_STATE 3 /* mask for the above */
+#define PNG_FP_SAW_SIGN 4 /* Saw +/- in current state */
+#define PNG_FP_SAW_DIGIT 8 /* Saw a digit in current state */
+#define PNG_FP_SAW_DOT 16 /* Saw a dot in current state */
+#define PNG_FP_SAW_E 32 /* Saw an E (or e) in current state */
+#define PNG_FP_SAW_ANY 60 /* Saw any of the above 4 */
+
+/* These three values don't affect the parser. They are set but not used.
+ */
+#define PNG_FP_WAS_VALID 64 /* Preceding substring is a valid fp number */
+#define PNG_FP_NEGATIVE 128 /* A negative number, including "-0" */
+#define PNG_FP_NONZERO 256 /* A non-zero value */
+#define PNG_FP_STICKY 448 /* The above three flags */
+
+/* This is available for the caller to store in 'state' if required. Do not
+ * call the parser after setting it (the parser sometimes clears it.)
+ */
+#define PNG_FP_INVALID 512 /* Available for callers as a distinct value */
+
+/* Result codes for the parser (boolean - true means ok, false means
+ * not ok yet.)
+ */
+#define PNG_FP_MAYBE 0 /* The number may be valid in the future */
+#define PNG_FP_OK 1 /* The number is valid */
+
+/* Tests on the sticky non-zero and negative flags. To pass these checks
+ * the state must also indicate that the whole number is valid - this is
+ * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
+ * is equivalent to PNG_FP_OK above.)
+ */
+#define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
+ /* NZ_MASK: the string is valid and a non-zero negative value */
+#define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
+ /* Z MASK: the string is valid and a non-zero value. */
+ /* PNG_FP_SAW_DIGIT: the string is valid. */
+#define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
+#define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
+#define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
+
+/* The actual parser. This can be called repeatedly. It updates
+ * the index into the string and the state variable (which must
+ * be initialized to 0). It returns a result code, as above. There
+ * is no point calling the parser any more if it fails to advance to
+ * the end of the string - it is stuck on an invalid character (or
+ * terminated by '\0').
+ *
+ * Note that the pointer will consume an E or even an E+ and then leave
+ * a 'maybe' state even though a preceding integer.fraction is valid.
+ * The PNG_FP_WAS_VALID flag indicates that a preceding substring was
+ * a valid number. It's possible to recover from this by calling
+ * the parser again (from the start, with state 0) but with a string
+ * that omits the last character (i.e. set the size to the index of
+ * the problem character.) This has not been tested within libpng.
+ */
+PNG_INTERNAL_FUNCTION(int,png_check_fp_number,(png_const_charp string,
+ size_t size, int *statep, size_t *whereami),PNG_EMPTY);
+
+/* This is the same but it checks a complete string and returns true
+ * only if it just contains a floating point number. As of 1.5.4 this
+ * function also returns the state at the end of parsing the number if
+ * it was valid (otherwise it returns 0.) This can be used for testing
+ * for negative or zero values using the sticky flag.
+ */
+PNG_INTERNAL_FUNCTION(int,png_check_fp_string,(png_const_charp string,
+ size_t size),PNG_EMPTY);
+#endif /* pCAL || sCAL */
+
+#if defined(PNG_READ_GAMMA_SUPPORTED) ||\
+ defined(PNG_COLORSPACE_SUPPORTED) ||\
+ defined(PNG_INCH_CONVERSIONS_SUPPORTED) ||\
+ defined(PNG_READ_pHYs_SUPPORTED)
+/* Added at libpng version 1.5.0 */
+/* This is a utility to provide a*times/div (rounded) and indicate
+ * if there is an overflow. The result is a boolean - false (0)
+ * for overflow, true (1) if no overflow, in which case *res
+ * holds the result.
+ */
+PNG_INTERNAL_FUNCTION(int,png_muldiv,(png_fixed_point_p res, png_fixed_point a,
+ png_int_32 multiplied_by, png_int_32 divided_by),PNG_EMPTY);
+
+/* Calculate a reciprocal - used for gamma values. This returns
+ * 0 if the argument is 0 in order to maintain an undefined value;
+ * there are no warnings.
+ */
+PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal,(png_fixed_point a),
+ PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* The same but gives a reciprocal of the product of two fixed point
+ * values. Accuracy is suitable for gamma calculations but this is
+ * not exact - use png_muldiv for that. Only required at present on read.
+ */
+PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal2,(png_fixed_point a,
+ png_fixed_point b),PNG_EMPTY);
+
+/* Return true if the gamma value is significantly different from 1.0 */
+PNG_INTERNAL_FUNCTION(int,png_gamma_significant,(png_fixed_point gamma_value),
+ PNG_EMPTY);
+
+/* PNGv3: 'resolve' the file gamma according to the new PNGv3 rules for colour
+ * space information.
+ *
+ * NOTE: this uses precisely those chunks that libpng supports. For example it
+ * doesn't use iCCP and it can only use cICP for known and manageable
+ * transforms. For this reason a gamma specified by png_set_gamma always takes
+ * precedence.
+ */
+PNG_INTERNAL_FUNCTION(png_fixed_point,png_resolve_file_gamma,
+ (png_const_structrp png_ptr),PNG_EMPTY);
+
+/* Internal fixed point gamma correction. These APIs are called as
+ * required to convert single values - they don't need to be fast,
+ * they are not used when processing image pixel values.
+ *
+ * While the input is an 'unsigned' value it must actually be the
+ * correct bit value - 0..255 or 0..65535 as required.
+ */
+PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_correct,(png_structrp png_ptr,
+ unsigned int value, png_fixed_point gamma_value),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_16bit_correct,(unsigned int value,
+ png_fixed_point gamma_value),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(png_byte,png_gamma_8bit_correct,(unsigned int value,
+ png_fixed_point gamma_value),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_destroy_gamma_table,(png_structrp png_ptr),
+ PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_build_gamma_table,(png_structrp png_ptr,
+ int bit_depth),PNG_EMPTY);
+#endif /* READ_GAMMA */
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+/* Set the RGB coefficients if not already set by png_set_rgb_to_gray */
+PNG_INTERNAL_FUNCTION(void,png_set_rgb_coefficients,(png_structrp png_ptr),
+ PNG_EMPTY);
+#endif
+
+#if defined(PNG_cHRM_SUPPORTED) || defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+PNG_INTERNAL_FUNCTION(int,png_XYZ_from_xy,(png_XYZ *XYZ, const png_xy *xy),
+ PNG_EMPTY);
+#endif /* cHRM || READ_RGB_TO_GRAY */
+
+#ifdef PNG_COLORSPACE_SUPPORTED
+PNG_INTERNAL_FUNCTION(int,png_xy_from_XYZ,(png_xy *xy, const png_XYZ *XYZ),
+ PNG_EMPTY);
+#endif
+
+/* SIMPLIFIED READ/WRITE SUPPORT */
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
+ defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+/* The internal structure that png_image::opaque points to. */
+typedef struct png_control
+{
+ png_structp png_ptr;
+ png_infop info_ptr;
+ png_voidp error_buf; /* Always a jmp_buf at present. */
+
+ png_const_bytep memory; /* Memory buffer. */
+ size_t size; /* Size of the memory buffer. */
+
+ unsigned int for_write :1; /* Otherwise it is a read structure */
+ unsigned int owned_file :1; /* We own the file in io_ptr */
+} png_control;
+
+/* Return the pointer to the jmp_buf from a png_control: necessary because C
+ * does not reveal the type of the elements of jmp_buf.
+ */
+#ifdef __cplusplus
+# define png_control_jmp_buf(pc) (((jmp_buf*)((pc)->error_buf))[0])
+#else
+# define png_control_jmp_buf(pc) ((pc)->error_buf)
+#endif
+
+/* Utility to safely execute a piece of libpng code catching and logging any
+ * errors that might occur. Returns true on success, false on failure (either
+ * of the function or as a result of a png_error.)
+ */
+PNG_INTERNAL_CALLBACK(void,png_safe_error,(png_structp png_ptr,
+ png_const_charp error_message),PNG_NORETURN);
+
+#ifdef PNG_WARNINGS_SUPPORTED
+PNG_INTERNAL_CALLBACK(void,png_safe_warning,(png_structp png_ptr,
+ png_const_charp warning_message),PNG_EMPTY);
+#else
+# define png_safe_warning 0/*dummy argument*/
+#endif
+
+PNG_INTERNAL_FUNCTION(int,png_safe_execute,(png_imagep image,
+ int (*function)(png_voidp), png_voidp arg),PNG_EMPTY);
+
+/* Utility to log an error; this also cleans up the png_image; the function
+ * always returns 0 (false).
+ */
+PNG_INTERNAL_FUNCTION(int,png_image_error,(png_imagep image,
+ png_const_charp error_message),PNG_EMPTY);
+
+#ifndef PNG_SIMPLIFIED_READ_SUPPORTED
+/* png_image_free is used by the write code but not exported */
+PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY);
+#endif /* !SIMPLIFIED_READ */
+
+#endif /* SIMPLIFIED READ/WRITE */
+
+/* These are initialization functions for hardware specific PNG filter
+ * optimizations; list these here then select the appropriate one at compile
+ * time using the macro PNG_FILTER_OPTIMIZATIONS. If the macro is not defined
+ * the generic code is used.
+ */
+#ifdef PNG_FILTER_OPTIMIZATIONS
+PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structp png_ptr,
+ unsigned int bpp), PNG_EMPTY);
+ /* Just declare the optimization that will be used */
+#else
+ /* List *all* the possible optimizations here - this branch is required if
+ * the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in
+ * CFLAGS in place of CPPFLAGS *and* uses symbol prefixing.
+ */
+# if PNG_ARM_NEON_OPT > 0
+PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon,
+ (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
+#endif
+
+#if PNG_MIPS_MSA_IMPLEMENTATION == 1
+PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_mips,
+ (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
+#endif
+
+# if PNG_MIPS_MMI_IMPLEMENTATION > 0
+PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_mips,
+ (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
+# endif
+
+# if PNG_INTEL_SSE_IMPLEMENTATION > 0
+PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_sse2,
+ (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
+# endif
+#endif
+
+#if PNG_LOONGARCH_LSX_OPT > 0
+PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_lsx,
+ (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
+#endif
+
+# if PNG_RISCV_RVV_OPT > 0
+PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_rvv,
+ (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
+#endif
+
+PNG_INTERNAL_FUNCTION(png_uint_32, png_check_keyword, (png_structrp png_ptr,
+ png_const_charp key, png_bytep new_key), PNG_EMPTY);
+
+#if PNG_ARM_NEON_IMPLEMENTATION == 1
+PNG_INTERNAL_FUNCTION(void,
+ png_riffle_palette_neon,
+ (png_structrp),
+ PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(int,
+ png_do_expand_palette_rgba8_neon,
+ (png_structrp,
+ png_row_infop,
+ png_const_bytep,
+ const png_bytepp,
+ const png_bytepp),
+ PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(int,
+ png_do_expand_palette_rgb8_neon,
+ (png_structrp,
+ png_row_infop,
+ png_const_bytep,
+ const png_bytepp,
+ const png_bytepp),
+ PNG_EMPTY);
+#endif
+
+/* Maintainer: Put new private prototypes here ^ */
+
+#include "pngdebug.h"
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* PNG_VERSION_INFO_ONLY */
diff --git a/libs/imagequant/external/libpng/pngread.c b/libs/imagequant/external/libpng/pngread.c
new file mode 100644
index 00000000..a0dbf2ae
--- /dev/null
+++ b/libs/imagequant/external/libpng/pngread.c
@@ -0,0 +1,4093 @@
+/* pngread.c - read a PNG file
+ *
+ * Copyright (c) 2018-2025 Cosmin Truta
+ * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file contains routines that an application calls directly to
+ * read a PNG file or stream.
+ */
+
+#include "pngpriv.h"
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) && defined(PNG_STDIO_SUPPORTED)
+# include
+#endif
+
+#ifdef PNG_READ_SUPPORTED
+
+/* Create a PNG structure for reading, and allocate any memory needed. */
+PNG_FUNCTION(png_structp,PNGAPI
+png_create_read_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED)
+{
+#ifndef PNG_USER_MEM_SUPPORTED
+ png_structp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
+ error_fn, warn_fn, NULL, NULL, NULL);
+#else
+ return png_create_read_struct_2(user_png_ver, error_ptr, error_fn,
+ warn_fn, NULL, NULL, NULL);
+}
+
+/* Alternate create PNG structure for reading, and allocate any memory
+ * needed.
+ */
+PNG_FUNCTION(png_structp,PNGAPI
+png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+ png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
+{
+ png_structp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
+ error_fn, warn_fn, mem_ptr, malloc_fn, free_fn);
+#endif /* USER_MEM */
+
+ if (png_ptr != NULL)
+ {
+ png_ptr->mode = PNG_IS_READ_STRUCT;
+
+ /* Added in libpng-1.6.0; this can be used to detect a read structure if
+ * required (it will be zero in a write structure.)
+ */
+# ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+ png_ptr->IDAT_read_size = PNG_IDAT_READ_SIZE;
+# endif
+
+# ifdef PNG_BENIGN_READ_ERRORS_SUPPORTED
+ png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN;
+
+ /* In stable builds only warn if an application error can be completely
+ * handled.
+ */
+# if PNG_RELEASE_BUILD
+ png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN;
+# endif
+# endif
+
+ /* TODO: delay this, it can be done in png_init_io (if the app doesn't
+ * do it itself) avoiding setting the default function if it is not
+ * required.
+ */
+ png_set_read_fn(png_ptr, NULL, NULL);
+ }
+
+ return png_ptr;
+}
+
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the information before the actual image data. This has been
+ * changed in v0.90 to allow reading a file that already has the magic
+ * bytes read from the stream. You can tell libpng how many bytes have
+ * been read from the beginning of the stream (up to the maximum of 8)
+ * via png_set_sig_bytes(), and we will only check the remaining bytes
+ * here. The application can then have access to the signature bytes we
+ * read if it is determined that this isn't a valid PNG file.
+ */
+void PNGAPI
+png_read_info(png_structrp png_ptr, png_inforp info_ptr)
+{
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ int keep;
+#endif
+
+ png_debug(1, "in png_read_info");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ /* Read and check the PNG file signature. */
+ png_read_sig(png_ptr, info_ptr);
+
+ for (;;)
+ {
+ png_uint_32 length = png_read_chunk_header(png_ptr);
+ png_uint_32 chunk_name = png_ptr->chunk_name;
+
+ /* IDAT logic needs to happen here to simplify getting the two flags
+ * right.
+ */
+ if (chunk_name == png_IDAT)
+ {
+ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_chunk_error(png_ptr, "Missing IHDR before IDAT");
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+ (png_ptr->mode & PNG_HAVE_PLTE) == 0)
+ png_chunk_error(png_ptr, "Missing PLTE before IDAT");
+
+ else if ((png_ptr->mode & PNG_AFTER_IDAT) != 0)
+ png_chunk_benign_error(png_ptr, "Too many IDATs found");
+
+ png_ptr->mode |= PNG_HAVE_IDAT;
+ }
+
+ else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+ {
+ png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ }
+
+ if (chunk_name == png_IHDR)
+ png_handle_chunk(png_ptr, info_ptr, length);
+
+ else if (chunk_name == png_IEND)
+ png_handle_chunk(png_ptr, info_ptr, length);
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
+ {
+ png_handle_unknown(png_ptr, info_ptr, length, keep);
+
+ if (chunk_name == png_PLTE)
+ png_ptr->mode |= PNG_HAVE_PLTE;
+
+ else if (chunk_name == png_IDAT)
+ {
+ png_ptr->idat_size = 0; /* It has been consumed */
+ break;
+ }
+ }
+#endif
+
+ else if (chunk_name == png_IDAT)
+ {
+ png_ptr->idat_size = length;
+ break;
+ }
+
+ else
+ png_handle_chunk(png_ptr, info_ptr, length);
+ }
+}
+#endif /* SEQUENTIAL_READ */
+
+/* Optional call to update the users info_ptr structure */
+void PNGAPI
+png_read_update_info(png_structrp png_ptr, png_inforp info_ptr)
+{
+ png_debug(1, "in png_read_update_info");
+
+ if (png_ptr != NULL)
+ {
+ if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
+ {
+ png_read_start_row(png_ptr);
+
+# ifdef PNG_READ_TRANSFORMS_SUPPORTED
+ png_read_transform_info(png_ptr, info_ptr);
+# else
+ PNG_UNUSED(info_ptr)
+# endif
+ }
+
+ /* New in 1.6.0 this avoids the bug of doing the initializations twice */
+ else
+ png_app_error(png_ptr,
+ "png_read_update_info/png_start_read_image: duplicate call");
+ }
+}
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Initialize palette, background, etc, after transformations
+ * are set, but before any reading takes place. This allows
+ * the user to obtain a gamma-corrected palette, for example.
+ * If the user doesn't call this, we will do it ourselves.
+ */
+void PNGAPI
+png_start_read_image(png_structrp png_ptr)
+{
+ png_debug(1, "in png_start_read_image");
+
+ if (png_ptr != NULL)
+ {
+ if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
+ png_read_start_row(png_ptr);
+
+ /* New in 1.6.0 this avoids the bug of doing the initializations twice */
+ else
+ png_app_error(png_ptr,
+ "png_start_read_image/png_read_update_info: duplicate call");
+ }
+}
+#endif /* SEQUENTIAL_READ */
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+/* Undoes intrapixel differencing,
+ * NOTE: this is apparently only supported in the 'sequential' reader.
+ */
+static void
+png_do_read_intrapixel(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_read_intrapixel");
+
+ if (
+ (row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ {
+ int bytes_per_pixel;
+ png_uint_32 row_width = row_info->width;
+
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ bytes_per_pixel = 3;
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ bytes_per_pixel = 4;
+
+ else
+ return;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+ {
+ *(rp) = (png_byte)((256 + *rp + *(rp + 1)) & 0xff);
+ *(rp+2) = (png_byte)((256 + *(rp + 2) + *(rp + 1)) & 0xff);
+ }
+ }
+ else if (row_info->bit_depth == 16)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ bytes_per_pixel = 6;
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ bytes_per_pixel = 8;
+
+ else
+ return;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+ {
+ png_uint_32 s0 = (png_uint_32)(*(rp ) << 8) | *(rp + 1);
+ png_uint_32 s1 = (png_uint_32)(*(rp + 2) << 8) | *(rp + 3);
+ png_uint_32 s2 = (png_uint_32)(*(rp + 4) << 8) | *(rp + 5);
+ png_uint_32 red = (s0 + s1 + 65536) & 0xffff;
+ png_uint_32 blue = (s2 + s1 + 65536) & 0xffff;
+ *(rp ) = (png_byte)((red >> 8) & 0xff);
+ *(rp + 1) = (png_byte)(red & 0xff);
+ *(rp + 4) = (png_byte)((blue >> 8) & 0xff);
+ *(rp + 5) = (png_byte)(blue & 0xff);
+ }
+ }
+ }
+}
+#endif /* MNG_FEATURES */
+
+void PNGAPI
+png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row)
+{
+ png_row_info row_info;
+
+ if (png_ptr == NULL)
+ return;
+
+ png_debug2(1, "in png_read_row (row %lu, pass %d)",
+ (unsigned long)png_ptr->row_number, png_ptr->pass);
+
+ /* png_read_start_row sets the information (in particular iwidth) for this
+ * interlace pass.
+ */
+ if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
+ png_read_start_row(png_ptr);
+
+ /* 1.5.6: row_info moved out of png_struct to a local here. */
+ row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */
+ row_info.color_type = png_ptr->color_type;
+ row_info.bit_depth = png_ptr->bit_depth;
+ row_info.channels = png_ptr->channels;
+ row_info.pixel_depth = png_ptr->pixel_depth;
+ row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
+
+#ifdef PNG_WARNINGS_SUPPORTED
+ if (png_ptr->row_number == 0 && png_ptr->pass == 0)
+ {
+ /* Check for transforms that have been set but were defined out */
+#if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED)
+ if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
+ png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined");
+#endif
+
+#if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED)
+ if ((png_ptr->transformations & PNG_FILLER) != 0)
+ png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined");
+#endif
+
+#if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
+ !defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
+ png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined");
+#endif
+
+#if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED)
+ if ((png_ptr->transformations & PNG_PACK) != 0)
+ png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined");
+#endif
+
+#if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED)
+ if ((png_ptr->transformations & PNG_SHIFT) != 0)
+ png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined");
+#endif
+
+#if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED)
+ if ((png_ptr->transformations & PNG_BGR) != 0)
+ png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined");
+#endif
+
+#if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED)
+ if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
+ png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined");
+#endif
+ }
+#endif /* WARNINGS */
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ /* If interlaced and we do not need a new row, combine row and return.
+ * Notice that the pixels we have from previous rows have been transformed
+ * already; we can only combine like with like (transformed or
+ * untransformed) and, because of the libpng API for interlaced images, this
+ * means we must transform before de-interlacing.
+ */
+ if (png_ptr->interlaced != 0 &&
+ (png_ptr->transformations & PNG_INTERLACE) != 0)
+ {
+ switch (png_ptr->pass)
+ {
+ case 0:
+ if (png_ptr->row_number & 0x07)
+ {
+ if (dsp_row != NULL)
+ png_combine_row(png_ptr, dsp_row, 1/*display*/);
+ png_read_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 1:
+ if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
+ {
+ if (dsp_row != NULL)
+ png_combine_row(png_ptr, dsp_row, 1/*display*/);
+
+ png_read_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 2:
+ if ((png_ptr->row_number & 0x07) != 4)
+ {
+ if (dsp_row != NULL && (png_ptr->row_number & 4))
+ png_combine_row(png_ptr, dsp_row, 1/*display*/);
+
+ png_read_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 3:
+ if ((png_ptr->row_number & 3) || png_ptr->width < 3)
+ {
+ if (dsp_row != NULL)
+ png_combine_row(png_ptr, dsp_row, 1/*display*/);
+
+ png_read_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 4:
+ if ((png_ptr->row_number & 3) != 2)
+ {
+ if (dsp_row != NULL && (png_ptr->row_number & 2))
+ png_combine_row(png_ptr, dsp_row, 1/*display*/);
+
+ png_read_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 5:
+ if ((png_ptr->row_number & 1) || png_ptr->width < 2)
+ {
+ if (dsp_row != NULL)
+ png_combine_row(png_ptr, dsp_row, 1/*display*/);
+
+ png_read_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ default:
+ case 6:
+ if ((png_ptr->row_number & 1) == 0)
+ {
+ png_read_finish_row(png_ptr);
+ return;
+ }
+ break;
+ }
+ }
+#endif
+
+ if ((png_ptr->mode & PNG_HAVE_IDAT) == 0)
+ png_error(png_ptr, "Invalid attempt to read row data");
+
+ /* Fill the row with IDAT data: */
+ png_ptr->row_buf[0]=255; /* to force error if no data was found */
+ png_read_IDAT_data(png_ptr, png_ptr->row_buf, row_info.rowbytes + 1);
+
+ if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE)
+ {
+ if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST)
+ png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1,
+ png_ptr->prev_row + 1, png_ptr->row_buf[0]);
+ else
+ png_error(png_ptr, "bad adaptive filter value");
+ }
+
+ /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before
+ * 1.5.6, while the buffer really is this big in current versions of libpng
+ * it may not be in the future, so this was changed just to copy the
+ * interlaced count:
+ */
+ memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
+ (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
+ {
+ /* Intrapixel differencing */
+ png_do_read_intrapixel(&row_info, png_ptr->row_buf + 1);
+ }
+#endif
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+ if (png_ptr->transformations
+# ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+ || png_ptr->num_palette_max >= 0
+# endif
+ )
+ png_do_read_transformations(png_ptr, &row_info);
+#endif
+
+ /* The transformed pixel depth should match the depth now in row_info. */
+ if (png_ptr->transformed_pixel_depth == 0)
+ {
+ png_ptr->transformed_pixel_depth = row_info.pixel_depth;
+ if (row_info.pixel_depth > png_ptr->maximum_pixel_depth)
+ png_error(png_ptr, "sequential row overflow");
+ }
+
+ else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth)
+ png_error(png_ptr, "internal sequential row size calculation error");
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ /* Expand interlaced rows to full size */
+ if (png_ptr->interlaced != 0 &&
+ (png_ptr->transformations & PNG_INTERLACE) != 0)
+ {
+ if (png_ptr->pass < 6)
+ png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
+ png_ptr->transformations);
+
+ if (dsp_row != NULL)
+ png_combine_row(png_ptr, dsp_row, 1/*display*/);
+
+ if (row != NULL)
+ png_combine_row(png_ptr, row, 0/*row*/);
+ }
+
+ else
+#endif
+ {
+ if (row != NULL)
+ png_combine_row(png_ptr, row, -1/*ignored*/);
+
+ if (dsp_row != NULL)
+ png_combine_row(png_ptr, dsp_row, -1/*ignored*/);
+ }
+ png_read_finish_row(png_ptr);
+
+ if (png_ptr->read_row_fn != NULL)
+ (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
+
+}
+#endif /* SEQUENTIAL_READ */
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read one or more rows of image data. If the image is interlaced,
+ * and png_set_interlace_handling() has been called, the rows need to
+ * contain the contents of the rows from the previous pass. If the
+ * image has alpha or transparency, and png_handle_alpha()[*] has been
+ * called, the rows contents must be initialized to the contents of the
+ * screen.
+ *
+ * "row" holds the actual image, and pixels are placed in it
+ * as they arrive. If the image is displayed after each pass, it will
+ * appear to "sparkle" in. "display_row" can be used to display a
+ * "chunky" progressive image, with finer detail added as it becomes
+ * available. If you do not want this "chunky" display, you may pass
+ * NULL for display_row. If you do not want the sparkle display, and
+ * you have not called png_handle_alpha(), you may pass NULL for rows.
+ * If you have called png_handle_alpha(), and the image has either an
+ * alpha channel or a transparency chunk, you must provide a buffer for
+ * rows. In this case, you do not have to provide a display_row buffer
+ * also, but you may. If the image is not interlaced, or if you have
+ * not called png_set_interlace_handling(), the display_row buffer will
+ * be ignored, so pass NULL to it.
+ *
+ * [*] png_handle_alpha() does not exist yet, as of this version of libpng
+ */
+
+void PNGAPI
+png_read_rows(png_structrp png_ptr, png_bytepp row,
+ png_bytepp display_row, png_uint_32 num_rows)
+{
+ png_uint_32 i;
+ png_bytepp rp;
+ png_bytepp dp;
+
+ png_debug(1, "in png_read_rows");
+
+ if (png_ptr == NULL)
+ return;
+
+ rp = row;
+ dp = display_row;
+ if (rp != NULL && dp != NULL)
+ for (i = 0; i < num_rows; i++)
+ {
+ png_bytep rptr = *rp++;
+ png_bytep dptr = *dp++;
+
+ png_read_row(png_ptr, rptr, dptr);
+ }
+
+ else if (rp != NULL)
+ for (i = 0; i < num_rows; i++)
+ {
+ png_bytep rptr = *rp;
+ png_read_row(png_ptr, rptr, NULL);
+ rp++;
+ }
+
+ else if (dp != NULL)
+ for (i = 0; i < num_rows; i++)
+ {
+ png_bytep dptr = *dp;
+ png_read_row(png_ptr, NULL, dptr);
+ dp++;
+ }
+}
+#endif /* SEQUENTIAL_READ */
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the entire image. If the image has an alpha channel or a tRNS
+ * chunk, and you have called png_handle_alpha()[*], you will need to
+ * initialize the image to the current image that PNG will be overlaying.
+ * We set the num_rows again here, in case it was incorrectly set in
+ * png_read_start_row() by a call to png_read_update_info() or
+ * png_start_read_image() if png_set_interlace_handling() wasn't called
+ * prior to either of these functions like it should have been. You can
+ * only call this function once. If you desire to have an image for
+ * each pass of a interlaced image, use png_read_rows() instead.
+ *
+ * [*] png_handle_alpha() does not exist yet, as of this version of libpng
+ */
+void PNGAPI
+png_read_image(png_structrp png_ptr, png_bytepp image)
+{
+ png_uint_32 i, image_height;
+ int pass, j;
+ png_bytepp rp;
+
+ png_debug(1, "in png_read_image");
+
+ if (png_ptr == NULL)
+ return;
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
+ {
+ pass = png_set_interlace_handling(png_ptr);
+ /* And make sure transforms are initialized. */
+ png_start_read_image(png_ptr);
+ }
+ else
+ {
+ if (png_ptr->interlaced != 0 &&
+ (png_ptr->transformations & PNG_INTERLACE) == 0)
+ {
+ /* Caller called png_start_read_image or png_read_update_info without
+ * first turning on the PNG_INTERLACE transform. We can fix this here,
+ * but the caller should do it!
+ */
+ png_warning(png_ptr, "Interlace handling should be turned on when "
+ "using png_read_image");
+ /* Make sure this is set correctly */
+ png_ptr->num_rows = png_ptr->height;
+ }
+
+ /* Obtain the pass number, which also turns on the PNG_INTERLACE flag in
+ * the above error case.
+ */
+ pass = png_set_interlace_handling(png_ptr);
+ }
+#else
+ if (png_ptr->interlaced)
+ png_error(png_ptr,
+ "Cannot read interlaced image -- interlace handler disabled");
+
+ pass = 1;
+#endif
+
+ image_height=png_ptr->height;
+
+ for (j = 0; j < pass; j++)
+ {
+ rp = image;
+ for (i = 0; i < image_height; i++)
+ {
+ png_read_row(png_ptr, *rp, NULL);
+ rp++;
+ }
+ }
+}
+#endif /* SEQUENTIAL_READ */
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the end of the PNG file. Will not read past the end of the
+ * file, will verify the end is accurate, and will read any comments
+ * or time information at the end of the file, if info is not NULL.
+ */
+void PNGAPI
+png_read_end(png_structrp png_ptr, png_inforp info_ptr)
+{
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ int keep;
+#endif
+
+ png_debug(1, "in png_read_end");
+
+ if (png_ptr == NULL)
+ return;
+
+ /* If png_read_end is called in the middle of reading the rows there may
+ * still be pending IDAT data and an owned zstream. Deal with this here.
+ */
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ if (png_chunk_unknown_handling(png_ptr, png_IDAT) == 0)
+#endif
+ png_read_finish_IDAT(png_ptr);
+
+#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
+ /* Report invalid palette index; added at libng-1.5.10 */
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+ png_ptr->num_palette_max >= png_ptr->num_palette)
+ png_benign_error(png_ptr, "Read palette index exceeding num_palette");
+#endif
+
+ do
+ {
+ png_uint_32 length = png_read_chunk_header(png_ptr);
+ png_uint_32 chunk_name = png_ptr->chunk_name;
+
+ if (chunk_name != png_IDAT)
+ png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
+
+ if (chunk_name == png_IEND)
+ png_handle_chunk(png_ptr, info_ptr, length);
+
+ else if (chunk_name == png_IHDR)
+ png_handle_chunk(png_ptr, info_ptr, length);
+
+ else if (info_ptr == NULL)
+ png_crc_finish(png_ptr, length);
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
+ {
+ if (chunk_name == png_IDAT)
+ {
+ if ((length > 0 && !(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED))
+ || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) != 0)
+ png_benign_error(png_ptr, ".Too many IDATs found");
+ }
+ png_handle_unknown(png_ptr, info_ptr, length, keep);
+ if (chunk_name == png_PLTE)
+ png_ptr->mode |= PNG_HAVE_PLTE;
+ }
+#endif
+
+ else if (chunk_name == png_IDAT)
+ {
+ /* Zero length IDATs are legal after the last IDAT has been
+ * read, but not after other chunks have been read. 1.6 does not
+ * always read all the deflate data; specifically it cannot be relied
+ * upon to read the Adler32 at the end. If it doesn't ignore IDAT
+ * chunks which are longer than zero as well:
+ */
+ if ((length > 0 && !(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED))
+ || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) != 0)
+ png_benign_error(png_ptr, "..Too many IDATs found");
+
+ png_crc_finish(png_ptr, length);
+ }
+
+ else
+ png_handle_chunk(png_ptr, info_ptr, length);
+ } while ((png_ptr->mode & PNG_HAVE_IEND) == 0);
+}
+#endif /* SEQUENTIAL_READ */
+
+/* Free all memory used in the read struct */
+static void
+png_read_destroy(png_structrp png_ptr)
+{
+ png_debug(1, "in png_read_destroy");
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ png_destroy_gamma_table(png_ptr);
+#endif
+
+ png_free(png_ptr, png_ptr->big_row_buf);
+ png_ptr->big_row_buf = NULL;
+ png_free(png_ptr, png_ptr->big_prev_row);
+ png_ptr->big_prev_row = NULL;
+ png_free(png_ptr, png_ptr->read_buffer);
+ png_ptr->read_buffer = NULL;
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+ png_free(png_ptr, png_ptr->palette_lookup);
+ png_ptr->palette_lookup = NULL;
+ png_free(png_ptr, png_ptr->quantize_index);
+ png_ptr->quantize_index = NULL;
+#endif
+
+ if ((png_ptr->free_me & PNG_FREE_PLTE) != 0)
+ {
+ png_zfree(png_ptr, png_ptr->palette);
+ png_ptr->palette = NULL;
+ }
+ png_ptr->free_me &= ~PNG_FREE_PLTE;
+
+#if defined(PNG_tRNS_SUPPORTED) || \
+ defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ if ((png_ptr->free_me & PNG_FREE_TRNS) != 0)
+ {
+ png_free(png_ptr, png_ptr->trans_alpha);
+ png_ptr->trans_alpha = NULL;
+ }
+ png_ptr->free_me &= ~PNG_FREE_TRNS;
+#endif
+
+ inflateEnd(&png_ptr->zstream);
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+ png_free(png_ptr, png_ptr->save_buffer);
+ png_ptr->save_buffer = NULL;
+#endif
+
+#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) && \
+ defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+ png_free(png_ptr, png_ptr->unknown_chunk.data);
+ png_ptr->unknown_chunk.data = NULL;
+#endif
+
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+ png_free(png_ptr, png_ptr->chunk_list);
+ png_ptr->chunk_list = NULL;
+#endif
+
+#if defined(PNG_READ_EXPAND_SUPPORTED) && \
+ (defined(PNG_ARM_NEON_IMPLEMENTATION) || \
+ defined(PNG_RISCV_RVV_IMPLEMENTATION))
+ png_free(png_ptr, png_ptr->riffled_palette);
+ png_ptr->riffled_palette = NULL;
+#endif
+
+ /* NOTE: the 'setjmp' buffer may still be allocated and the memory and error
+ * callbacks are still set at this point. They are required to complete the
+ * destruction of the png_struct itself.
+ */
+}
+
+/* Free all memory used by the read */
+void PNGAPI
+png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
+ png_infopp end_info_ptr_ptr)
+{
+ png_structrp png_ptr = NULL;
+
+ png_debug(1, "in png_destroy_read_struct");
+
+ if (png_ptr_ptr != NULL)
+ png_ptr = *png_ptr_ptr;
+
+ if (png_ptr == NULL)
+ return;
+
+ /* libpng 1.6.0: use the API to destroy info structs to ensure consistent
+ * behavior. Prior to 1.6.0 libpng did extra 'info' destruction in this API.
+ * The extra was, apparently, unnecessary yet this hides memory leak bugs.
+ */
+ png_destroy_info_struct(png_ptr, end_info_ptr_ptr);
+ png_destroy_info_struct(png_ptr, info_ptr_ptr);
+
+ *png_ptr_ptr = NULL;
+ png_read_destroy(png_ptr);
+ png_destroy_png_struct(png_ptr);
+}
+
+void PNGAPI
+png_set_read_status_fn(png_structrp png_ptr, png_read_status_ptr read_row_fn)
+{
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->read_row_fn = read_row_fn;
+}
+
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+void PNGAPI
+png_read_png(png_structrp png_ptr, png_inforp info_ptr,
+ int transforms, voidp params)
+{
+ png_debug(1, "in png_read_png");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ /* png_read_info() gives us all of the information from the
+ * PNG file before the first IDAT (image data chunk).
+ */
+ png_read_info(png_ptr, info_ptr);
+ if (info_ptr->height > PNG_UINT_32_MAX/(sizeof (png_bytep)))
+ png_error(png_ptr, "Image is too high to process with png_read_png()");
+
+ /* -------------- image transformations start here ------------------- */
+ /* libpng 1.6.10: add code to cause a png_app_error if a selected TRANSFORM
+ * is not implemented. This will only happen in de-configured (non-default)
+ * libpng builds. The results can be unexpected - png_read_png may return
+ * short or mal-formed rows because the transform is skipped.
+ */
+
+ /* Tell libpng to strip 16-bit/color files down to 8 bits per color.
+ */
+ if ((transforms & PNG_TRANSFORM_SCALE_16) != 0)
+ /* Added at libpng-1.5.4. "strip_16" produces the same result that it
+ * did in earlier versions, while "scale_16" is now more accurate.
+ */
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+ png_set_scale_16(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_SCALE_16 not supported");
+#endif
+
+ /* If both SCALE and STRIP are required pngrtran will effectively cancel the
+ * latter by doing SCALE first. This is ok and allows apps not to check for
+ * which is supported to get the right answer.
+ */
+ if ((transforms & PNG_TRANSFORM_STRIP_16) != 0)
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+ png_set_strip_16(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_16 not supported");
+#endif
+
+ /* Strip alpha bytes from the input data without combining with
+ * the background (not recommended).
+ */
+ if ((transforms & PNG_TRANSFORM_STRIP_ALPHA) != 0)
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+ png_set_strip_alpha(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_ALPHA not supported");
+#endif
+
+ /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single
+ * byte into separate bytes (useful for paletted and grayscale images).
+ */
+ if ((transforms & PNG_TRANSFORM_PACKING) != 0)
+#ifdef PNG_READ_PACK_SUPPORTED
+ png_set_packing(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_PACKING not supported");
+#endif
+
+ /* Change the order of packed pixels to least significant bit first
+ * (not useful if you are using png_set_packing).
+ */
+ if ((transforms & PNG_TRANSFORM_PACKSWAP) != 0)
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ png_set_packswap(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_PACKSWAP not supported");
+#endif
+
+ /* Expand paletted colors into true RGB triplets
+ * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel
+ * Expand paletted or RGB images with transparency to full alpha
+ * channels so the data will be available as RGBA quartets.
+ */
+ if ((transforms & PNG_TRANSFORM_EXPAND) != 0)
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ png_set_expand(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_EXPAND not supported");
+#endif
+
+ /* We don't handle background color or gamma transformation or quantizing.
+ */
+
+ /* Invert monochrome files to have 0 as white and 1 as black
+ */
+ if ((transforms & PNG_TRANSFORM_INVERT_MONO) != 0)
+#ifdef PNG_READ_INVERT_SUPPORTED
+ png_set_invert_mono(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_MONO not supported");
+#endif
+
+ /* If you want to shift the pixel values from the range [0,255] or
+ * [0,65535] to the original [0,7] or [0,31], or whatever range the
+ * colors were originally in:
+ */
+ if ((transforms & PNG_TRANSFORM_SHIFT) != 0)
+#ifdef PNG_READ_SHIFT_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_sBIT) != 0)
+ png_set_shift(png_ptr, &info_ptr->sig_bit);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported");
+#endif
+
+ /* Flip the RGB pixels to BGR (or RGBA to BGRA) */
+ if ((transforms & PNG_TRANSFORM_BGR) != 0)
+#ifdef PNG_READ_BGR_SUPPORTED
+ png_set_bgr(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_BGR not supported");
+#endif
+
+ /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
+ if ((transforms & PNG_TRANSFORM_SWAP_ALPHA) != 0)
+#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
+ png_set_swap_alpha(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ALPHA not supported");
+#endif
+
+ /* Swap bytes of 16-bit files to least significant byte first */
+ if ((transforms & PNG_TRANSFORM_SWAP_ENDIAN) != 0)
+#ifdef PNG_READ_SWAP_SUPPORTED
+ png_set_swap(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ENDIAN not supported");
+#endif
+
+/* Added at libpng-1.2.41 */
+ /* Invert the alpha channel from opacity to transparency */
+ if ((transforms & PNG_TRANSFORM_INVERT_ALPHA) != 0)
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+ png_set_invert_alpha(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_ALPHA not supported");
+#endif
+
+/* Added at libpng-1.2.41 */
+ /* Expand grayscale image to RGB */
+ if ((transforms & PNG_TRANSFORM_GRAY_TO_RGB) != 0)
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+ png_set_gray_to_rgb(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_GRAY_TO_RGB not supported");
+#endif
+
+/* Added at libpng-1.5.4 */
+ if ((transforms & PNG_TRANSFORM_EXPAND_16) != 0)
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+ png_set_expand_16(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_EXPAND_16 not supported");
+#endif
+
+ /* We don't handle adding filler bytes */
+
+ /* We use png_read_image and rely on that for interlace handling, but we also
+ * call png_read_update_info therefore must turn on interlace handling now:
+ */
+ (void)png_set_interlace_handling(png_ptr);
+
+ /* Optional call to gamma correct and add the background to the palette
+ * and update info structure. REQUIRED if you are expecting libpng to
+ * update the palette for you (i.e., you selected such a transform above).
+ */
+ png_read_update_info(png_ptr, info_ptr);
+
+ /* -------------- image transformations end here ------------------- */
+
+ png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
+ if (info_ptr->row_pointers == NULL)
+ {
+ png_uint_32 iptr;
+
+ info_ptr->row_pointers = png_voidcast(png_bytepp, png_malloc(png_ptr,
+ info_ptr->height * (sizeof (png_bytep))));
+
+ for (iptr=0; iptrheight; iptr++)
+ info_ptr->row_pointers[iptr] = NULL;
+
+ info_ptr->free_me |= PNG_FREE_ROWS;
+
+ for (iptr = 0; iptr < info_ptr->height; iptr++)
+ info_ptr->row_pointers[iptr] = png_voidcast(png_bytep,
+ png_malloc(png_ptr, info_ptr->rowbytes));
+ }
+
+ png_read_image(png_ptr, info_ptr->row_pointers);
+ info_ptr->valid |= PNG_INFO_IDAT;
+
+ /* Read rest of file, and get additional chunks in info_ptr - REQUIRED */
+ png_read_end(png_ptr, info_ptr);
+
+ PNG_UNUSED(params)
+}
+#endif /* INFO_IMAGE */
+#endif /* SEQUENTIAL_READ */
+
+#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
+/* SIMPLIFIED READ
+ *
+ * This code currently relies on the sequential reader, though it could easily
+ * be made to work with the progressive one.
+ */
+/* Arguments to png_image_finish_read: */
+
+/* Encoding of PNG data (used by the color-map code) */
+# define P_NOTSET 0 /* File encoding not yet known */
+# define P_sRGB 1 /* 8-bit encoded to sRGB gamma */
+# define P_LINEAR 2 /* 16-bit linear: not encoded, NOT pre-multiplied! */
+# define P_FILE 3 /* 8-bit encoded to file gamma, not sRGB or linear */
+# define P_LINEAR8 4 /* 8-bit linear: only from a file value */
+
+/* Color-map processing: after libpng has run on the PNG image further
+ * processing may be needed to convert the data to color-map indices.
+ */
+#define PNG_CMAP_NONE 0
+#define PNG_CMAP_GA 1 /* Process GA data to a color-map with alpha */
+#define PNG_CMAP_TRANS 2 /* Process GA data to a background index */
+#define PNG_CMAP_RGB 3 /* Process RGB data */
+#define PNG_CMAP_RGB_ALPHA 4 /* Process RGBA data */
+
+/* The following document where the background is for each processing case. */
+#define PNG_CMAP_NONE_BACKGROUND 256
+#define PNG_CMAP_GA_BACKGROUND 231
+#define PNG_CMAP_TRANS_BACKGROUND 254
+#define PNG_CMAP_RGB_BACKGROUND 256
+#define PNG_CMAP_RGB_ALPHA_BACKGROUND 216
+
+typedef struct
+{
+ /* Arguments: */
+ png_imagep image;
+ png_voidp buffer;
+ png_int_32 row_stride;
+ png_voidp colormap;
+ png_const_colorp background;
+ /* Local variables: */
+ png_voidp local_row;
+ png_voidp first_row;
+ ptrdiff_t row_bytes; /* step between rows */
+ int file_encoding; /* E_ values above */
+ png_fixed_point gamma_to_linear; /* For P_FILE, reciprocal of gamma */
+ int colormap_processing; /* PNG_CMAP_ values above */
+} png_image_read_control;
+
+/* Do all the *safe* initialization - 'safe' means that png_error won't be
+ * called, so setting up the jmp_buf is not required. This means that anything
+ * called from here must *not* call png_malloc - it has to call png_malloc_warn
+ * instead so that control is returned safely back to this routine.
+ */
+static int
+png_image_read_init(png_imagep image)
+{
+ if (image->opaque == NULL)
+ {
+ png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, image,
+ png_safe_error, png_safe_warning);
+
+ /* And set the rest of the structure to NULL to ensure that the various
+ * fields are consistent.
+ */
+ memset(image, 0, (sizeof *image));
+ image->version = PNG_IMAGE_VERSION;
+
+ if (png_ptr != NULL)
+ {
+ png_infop info_ptr = png_create_info_struct(png_ptr);
+
+ if (info_ptr != NULL)
+ {
+ png_controlp control = png_voidcast(png_controlp,
+ png_malloc_warn(png_ptr, (sizeof *control)));
+
+ if (control != NULL)
+ {
+ memset(control, 0, (sizeof *control));
+
+ control->png_ptr = png_ptr;
+ control->info_ptr = info_ptr;
+ control->for_write = 0;
+
+ image->opaque = control;
+ return 1;
+ }
+
+ /* Error clean up */
+ png_destroy_info_struct(png_ptr, &info_ptr);
+ }
+
+ png_destroy_read_struct(&png_ptr, NULL, NULL);
+ }
+
+ return png_image_error(image, "png_image_read: out of memory");
+ }
+
+ return png_image_error(image, "png_image_read: opaque pointer not NULL");
+}
+
+/* Utility to find the base format of a PNG file from a png_struct. */
+static png_uint_32
+png_image_format(png_structrp png_ptr)
+{
+ png_uint_32 format = 0;
+
+ if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ format |= PNG_FORMAT_FLAG_COLOR;
+
+ if ((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+ format |= PNG_FORMAT_FLAG_ALPHA;
+
+ /* Use png_ptr here, not info_ptr, because by examination png_handle_tRNS
+ * sets the png_struct fields; that's all we are interested in here. The
+ * precise interaction with an app call to png_set_tRNS and PNG file reading
+ * is unclear.
+ */
+ else if (png_ptr->num_trans > 0)
+ format |= PNG_FORMAT_FLAG_ALPHA;
+
+ if (png_ptr->bit_depth == 16)
+ format |= PNG_FORMAT_FLAG_LINEAR;
+
+ if ((png_ptr->color_type & PNG_COLOR_MASK_PALETTE) != 0)
+ format |= PNG_FORMAT_FLAG_COLORMAP;
+
+ return format;
+}
+
+static int
+chromaticities_match_sRGB(const png_xy *xy)
+{
+# define sRGB_TOLERANCE 1000
+ static const png_xy sRGB_xy = /* From ITU-R BT.709-3 */
+ {
+ /* color x y */
+ /* red */ 64000, 33000,
+ /* green */ 30000, 60000,
+ /* blue */ 15000, 6000,
+ /* white */ 31270, 32900
+ };
+
+ if (PNG_OUT_OF_RANGE(xy->whitex, sRGB_xy.whitex,sRGB_TOLERANCE) ||
+ PNG_OUT_OF_RANGE(xy->whitey, sRGB_xy.whitey,sRGB_TOLERANCE) ||
+ PNG_OUT_OF_RANGE(xy->redx, sRGB_xy.redx, sRGB_TOLERANCE) ||
+ PNG_OUT_OF_RANGE(xy->redy, sRGB_xy.redy, sRGB_TOLERANCE) ||
+ PNG_OUT_OF_RANGE(xy->greenx, sRGB_xy.greenx,sRGB_TOLERANCE) ||
+ PNG_OUT_OF_RANGE(xy->greeny, sRGB_xy.greeny,sRGB_TOLERANCE) ||
+ PNG_OUT_OF_RANGE(xy->bluex, sRGB_xy.bluex, sRGB_TOLERANCE) ||
+ PNG_OUT_OF_RANGE(xy->bluey, sRGB_xy.bluey, sRGB_TOLERANCE))
+ return 0;
+ return 1;
+}
+
+/* Is the given gamma significantly different from sRGB? The test is the same
+ * one used in pngrtran.c when deciding whether to do gamma correction. The
+ * arithmetic optimizes the division by using the fact that the inverse of the
+ * file sRGB gamma is 2.2
+ */
+static int
+png_gamma_not_sRGB(png_fixed_point g)
+{
+ /* 1.6.47: use the same sanity checks as used in pngrtran.c */
+ if (g < PNG_LIB_GAMMA_MIN || g > PNG_LIB_GAMMA_MAX)
+ return 0; /* Includes the uninitialized value 0 */
+
+ return png_gamma_significant((g * 11 + 2)/5 /* i.e. *2.2, rounded */);
+}
+
+/* Do the main body of a 'png_image_begin_read' function; read the PNG file
+ * header and fill in all the information. This is executed in a safe context,
+ * unlike the init routine above.
+ */
+static int
+png_image_is_not_sRGB(png_const_structrp png_ptr)
+{
+ /* Does the colorspace **not** match sRGB? The flag is only set if the
+ * answer can be determined reliably.
+ *
+ * png_struct::chromaticities always exists since the simplified API
+ * requires rgb-to-gray. The mDCV, cICP and cHRM chunks may all set it to
+ * a non-sRGB value, so it needs to be checked but **only** if one of
+ * those chunks occured in the file.
+ */
+ /* Highest priority: check to be safe. */
+ if (png_has_chunk(png_ptr, cICP) || png_has_chunk(png_ptr, mDCV))
+ return !chromaticities_match_sRGB(&png_ptr->chromaticities);
+
+ /* If the image is marked as sRGB then it is... */
+ if (png_has_chunk(png_ptr, sRGB))
+ return 0;
+
+ /* Last stop: cHRM, must check: */
+ if (png_has_chunk(png_ptr, cHRM))
+ return !chromaticities_match_sRGB(&png_ptr->chromaticities);
+
+ /* Else default to sRGB */
+ return 0;
+}
+
+static int
+png_image_read_header(png_voidp argument)
+{
+ png_imagep image = png_voidcast(png_imagep, argument);
+ png_structrp png_ptr = image->opaque->png_ptr;
+ png_inforp info_ptr = image->opaque->info_ptr;
+
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+ png_set_benign_errors(png_ptr, 1/*warn*/);
+#endif
+ png_read_info(png_ptr, info_ptr);
+
+ /* Do this the fast way; just read directly out of png_struct. */
+ image->width = png_ptr->width;
+ image->height = png_ptr->height;
+
+ {
+ png_uint_32 format = png_image_format(png_ptr);
+
+ image->format = format;
+
+ /* Greyscale images don't (typically) have colour space information and
+ * using it is pretty much impossible, so use sRGB for grayscale (it
+ * doesn't matter r==g==b so the transform is irrelevant.)
+ */
+ if ((format & PNG_FORMAT_FLAG_COLOR) != 0 &&
+ png_image_is_not_sRGB(png_ptr))
+ image->flags |= PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB;
+ }
+
+ /* We need the maximum number of entries regardless of the format the
+ * application sets here.
+ */
+ {
+ png_uint_32 cmap_entries;
+
+ switch (png_ptr->color_type)
+ {
+ case PNG_COLOR_TYPE_GRAY:
+ cmap_entries = 1U << png_ptr->bit_depth;
+ break;
+
+ case PNG_COLOR_TYPE_PALETTE:
+ cmap_entries = (png_uint_32)png_ptr->num_palette;
+ break;
+
+ default:
+ cmap_entries = 256;
+ break;
+ }
+
+ if (cmap_entries > 256)
+ cmap_entries = 256;
+
+ image->colormap_entries = cmap_entries;
+ }
+
+ return 1;
+}
+
+#ifdef PNG_STDIO_SUPPORTED
+int PNGAPI
+png_image_begin_read_from_stdio(png_imagep image, FILE *file)
+{
+ if (image != NULL && image->version == PNG_IMAGE_VERSION)
+ {
+ if (file != NULL)
+ {
+ if (png_image_read_init(image) != 0)
+ {
+ /* This is slightly evil, but png_init_io doesn't do anything other
+ * than this and we haven't changed the standard IO functions so
+ * this saves a 'safe' function.
+ */
+ image->opaque->png_ptr->io_ptr = file;
+ return png_safe_execute(image, png_image_read_header, image);
+ }
+ }
+
+ else
+ return png_image_error(image,
+ "png_image_begin_read_from_stdio: invalid argument");
+ }
+
+ else if (image != NULL)
+ return png_image_error(image,
+ "png_image_begin_read_from_stdio: incorrect PNG_IMAGE_VERSION");
+
+ return 0;
+}
+
+int PNGAPI
+png_image_begin_read_from_file(png_imagep image, const char *file_name)
+{
+ if (image != NULL && image->version == PNG_IMAGE_VERSION)
+ {
+ if (file_name != NULL)
+ {
+ FILE *fp = fopen(file_name, "rb");
+
+ if (fp != NULL)
+ {
+ if (png_image_read_init(image) != 0)
+ {
+ image->opaque->png_ptr->io_ptr = fp;
+ image->opaque->owned_file = 1;
+ return png_safe_execute(image, png_image_read_header, image);
+ }
+
+ /* Clean up: just the opened file. */
+ (void)fclose(fp);
+ }
+
+ else
+ return png_image_error(image, strerror(errno));
+ }
+
+ else
+ return png_image_error(image,
+ "png_image_begin_read_from_file: invalid argument");
+ }
+
+ else if (image != NULL)
+ return png_image_error(image,
+ "png_image_begin_read_from_file: incorrect PNG_IMAGE_VERSION");
+
+ return 0;
+}
+#endif /* STDIO */
+
+static void PNGCBAPI
+png_image_memory_read(png_structp png_ptr, png_bytep out, size_t need)
+{
+ if (png_ptr != NULL)
+ {
+ png_imagep image = png_voidcast(png_imagep, png_ptr->io_ptr);
+ if (image != NULL)
+ {
+ png_controlp cp = image->opaque;
+ if (cp != NULL)
+ {
+ png_const_bytep memory = cp->memory;
+ size_t size = cp->size;
+
+ if (memory != NULL && size >= need)
+ {
+ memcpy(out, memory, need);
+ cp->memory = memory + need;
+ cp->size = size - need;
+ return;
+ }
+
+ png_error(png_ptr, "read beyond end of data");
+ }
+ }
+
+ png_error(png_ptr, "invalid memory read");
+ }
+}
+
+int PNGAPI png_image_begin_read_from_memory(png_imagep image,
+ png_const_voidp memory, size_t size)
+{
+ if (image != NULL && image->version == PNG_IMAGE_VERSION)
+ {
+ if (memory != NULL && size > 0)
+ {
+ if (png_image_read_init(image) != 0)
+ {
+ /* Now set the IO functions to read from the memory buffer and
+ * store it into io_ptr. Again do this in-place to avoid calling a
+ * libpng function that requires error handling.
+ */
+ image->opaque->memory = png_voidcast(png_const_bytep, memory);
+ image->opaque->size = size;
+ image->opaque->png_ptr->io_ptr = image;
+ image->opaque->png_ptr->read_data_fn = png_image_memory_read;
+
+ return png_safe_execute(image, png_image_read_header, image);
+ }
+ }
+
+ else
+ return png_image_error(image,
+ "png_image_begin_read_from_memory: invalid argument");
+ }
+
+ else if (image != NULL)
+ return png_image_error(image,
+ "png_image_begin_read_from_memory: incorrect PNG_IMAGE_VERSION");
+
+ return 0;
+}
+
+/* Utility function to skip chunks that are not used by the simplified image
+ * read functions and an appropriate macro to call it.
+ */
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+static void
+png_image_skip_unused_chunks(png_structrp png_ptr)
+{
+ /* Prepare the reader to ignore all recognized chunks whose data will not
+ * be used, i.e., all chunks recognized by libpng except for those
+ * involved in basic image reading:
+ *
+ * IHDR, PLTE, IDAT, IEND
+ *
+ * Or image data handling:
+ *
+ * tRNS, bKGD, gAMA, cHRM, sRGB, [iCCP] and sBIT.
+ *
+ * This provides a small performance improvement and eliminates any
+ * potential vulnerability to security problems in the unused chunks.
+ *
+ * At present the iCCP chunk data isn't used, so iCCP chunk can be ignored
+ * too. This allows the simplified API to be compiled without iCCP support.
+ */
+ {
+ static const png_byte chunks_to_process[] = {
+ 98, 75, 71, 68, '\0', /* bKGD */
+ 99, 72, 82, 77, '\0', /* cHRM */
+ 99, 73, 67, 80, '\0', /* cICP */
+ 103, 65, 77, 65, '\0', /* gAMA */
+ 109, 68, 67, 86, '\0', /* mDCV */
+ 115, 66, 73, 84, '\0', /* sBIT */
+ 115, 82, 71, 66, '\0', /* sRGB */
+ };
+
+ /* Ignore unknown chunks and all other chunks except for the
+ * IHDR, PLTE, tRNS, IDAT, and IEND chunks.
+ */
+ png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_NEVER,
+ NULL, -1);
+
+ /* But do not ignore image data handling chunks */
+ png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_AS_DEFAULT,
+ chunks_to_process, (int)/*SAFE*/(sizeof chunks_to_process)/5);
+ }
+}
+
+# define PNG_SKIP_CHUNKS(p) png_image_skip_unused_chunks(p)
+#else
+# define PNG_SKIP_CHUNKS(p) ((void)0)
+#endif /* HANDLE_AS_UNKNOWN */
+
+/* The following macro gives the exact rounded answer for all values in the
+ * range 0..255 (it actually divides by 51.2, but the rounding still generates
+ * the correct numbers 0..5
+ */
+#define PNG_DIV51(v8) (((v8) * 5 + 130) >> 8)
+
+/* Utility functions to make particular color-maps */
+static void
+set_file_encoding(png_image_read_control *display)
+{
+ png_structrp png_ptr = display->image->opaque->png_ptr;
+ png_fixed_point g = png_resolve_file_gamma(png_ptr);
+
+ /* PNGv3: the result may be 0 however the 'default_gamma' should have been
+ * set before this is called so zero is an error:
+ */
+ if (g == 0)
+ png_error(png_ptr, "internal: default gamma not set");
+
+ if (png_gamma_significant(g) != 0)
+ {
+ if (png_gamma_not_sRGB(g) != 0)
+ {
+ display->file_encoding = P_FILE;
+ display->gamma_to_linear = png_reciprocal(g);
+ }
+
+ else
+ display->file_encoding = P_sRGB;
+ }
+
+ else
+ display->file_encoding = P_LINEAR8;
+}
+
+static unsigned int
+decode_gamma(png_image_read_control *display, png_uint_32 value, int encoding)
+{
+ if (encoding == P_FILE) /* double check */
+ encoding = display->file_encoding;
+
+ if (encoding == P_NOTSET) /* must be the file encoding */
+ {
+ set_file_encoding(display);
+ encoding = display->file_encoding;
+ }
+
+ switch (encoding)
+ {
+ case P_FILE:
+ value = png_gamma_16bit_correct(value*257, display->gamma_to_linear);
+ break;
+
+ case P_sRGB:
+ value = png_sRGB_table[value];
+ break;
+
+ case P_LINEAR:
+ break;
+
+ case P_LINEAR8:
+ value *= 257;
+ break;
+
+#ifdef __GNUC__
+ default:
+ png_error(display->image->opaque->png_ptr,
+ "unexpected encoding (internal error)");
+#endif
+ }
+
+ return value;
+}
+
+static png_uint_32
+png_colormap_compose(png_image_read_control *display,
+ png_uint_32 foreground, int foreground_encoding, png_uint_32 alpha,
+ png_uint_32 background, int encoding)
+{
+ /* The file value is composed on the background, the background has the given
+ * encoding and so does the result, the file is encoded with P_FILE and the
+ * file and alpha are 8-bit values. The (output) encoding will always be
+ * P_LINEAR or P_sRGB.
+ */
+ png_uint_32 f = decode_gamma(display, foreground, foreground_encoding);
+ png_uint_32 b = decode_gamma(display, background, encoding);
+
+ /* The alpha is always an 8-bit value (it comes from the palette), the value
+ * scaled by 255 is what PNG_sRGB_FROM_LINEAR requires.
+ */
+ f = f * alpha + b * (255-alpha);
+
+ if (encoding == P_LINEAR)
+ {
+ /* Scale to 65535; divide by 255, approximately (in fact this is extremely
+ * accurate, it divides by 255.00000005937181414556, with no overflow.)
+ */
+ f *= 257; /* Now scaled by 65535 */
+ f += f >> 16;
+ f = (f+32768) >> 16;
+ }
+
+ else /* P_sRGB */
+ f = PNG_sRGB_FROM_LINEAR(f);
+
+ return f;
+}
+
+/* NOTE: P_LINEAR values to this routine must be 16-bit, but P_FILE values must
+ * be 8-bit.
+ */
+static void
+png_create_colormap_entry(png_image_read_control *display,
+ png_uint_32 ip, png_uint_32 red, png_uint_32 green, png_uint_32 blue,
+ png_uint_32 alpha, int encoding)
+{
+ png_imagep image = display->image;
+ int output_encoding = (image->format & PNG_FORMAT_FLAG_LINEAR) != 0 ?
+ P_LINEAR : P_sRGB;
+ int convert_to_Y = (image->format & PNG_FORMAT_FLAG_COLOR) == 0 &&
+ (red != green || green != blue);
+
+ if (ip > 255)
+ png_error(image->opaque->png_ptr, "color-map index out of range");
+
+ /* Update the cache with whether the file gamma is significantly different
+ * from sRGB.
+ */
+ if (encoding == P_FILE)
+ {
+ if (display->file_encoding == P_NOTSET)
+ set_file_encoding(display);
+
+ /* Note that the cached value may be P_FILE too, but if it is then the
+ * gamma_to_linear member has been set.
+ */
+ encoding = display->file_encoding;
+ }
+
+ if (encoding == P_FILE)
+ {
+ png_fixed_point g = display->gamma_to_linear;
+
+ red = png_gamma_16bit_correct(red*257, g);
+ green = png_gamma_16bit_correct(green*257, g);
+ blue = png_gamma_16bit_correct(blue*257, g);
+
+ if (convert_to_Y != 0 || output_encoding == P_LINEAR)
+ {
+ alpha *= 257;
+ encoding = P_LINEAR;
+ }
+
+ else
+ {
+ red = PNG_sRGB_FROM_LINEAR(red * 255);
+ green = PNG_sRGB_FROM_LINEAR(green * 255);
+ blue = PNG_sRGB_FROM_LINEAR(blue * 255);
+ encoding = P_sRGB;
+ }
+ }
+
+ else if (encoding == P_LINEAR8)
+ {
+ /* This encoding occurs quite frequently in test cases because PngSuite
+ * includes a gAMA 1.0 chunk with most images.
+ */
+ red *= 257;
+ green *= 257;
+ blue *= 257;
+ alpha *= 257;
+ encoding = P_LINEAR;
+ }
+
+ else if (encoding == P_sRGB &&
+ (convert_to_Y != 0 || output_encoding == P_LINEAR))
+ {
+ /* The values are 8-bit sRGB values, but must be converted to 16-bit
+ * linear.
+ */
+ red = png_sRGB_table[red];
+ green = png_sRGB_table[green];
+ blue = png_sRGB_table[blue];
+ alpha *= 257;
+ encoding = P_LINEAR;
+ }
+
+ /* This is set if the color isn't gray but the output is. */
+ if (encoding == P_LINEAR)
+ {
+ if (convert_to_Y != 0)
+ {
+ /* NOTE: these values are copied from png_do_rgb_to_gray */
+ png_uint_32 y = (png_uint_32)6968 * red + (png_uint_32)23434 * green +
+ (png_uint_32)2366 * blue;
+
+ if (output_encoding == P_LINEAR)
+ y = (y + 16384) >> 15;
+
+ else
+ {
+ /* y is scaled by 32768, we need it scaled by 255: */
+ y = (y + 128) >> 8;
+ y *= 255;
+ y = PNG_sRGB_FROM_LINEAR((y + 64) >> 7);
+ alpha = PNG_DIV257(alpha);
+ encoding = P_sRGB;
+ }
+
+ blue = red = green = y;
+ }
+
+ else if (output_encoding == P_sRGB)
+ {
+ red = PNG_sRGB_FROM_LINEAR(red * 255);
+ green = PNG_sRGB_FROM_LINEAR(green * 255);
+ blue = PNG_sRGB_FROM_LINEAR(blue * 255);
+ alpha = PNG_DIV257(alpha);
+ encoding = P_sRGB;
+ }
+ }
+
+ if (encoding != output_encoding)
+ png_error(image->opaque->png_ptr, "bad encoding (internal error)");
+
+ /* Store the value. */
+ {
+# ifdef PNG_FORMAT_AFIRST_SUPPORTED
+ int afirst = (image->format & PNG_FORMAT_FLAG_AFIRST) != 0 &&
+ (image->format & PNG_FORMAT_FLAG_ALPHA) != 0;
+# else
+# define afirst 0
+# endif
+# ifdef PNG_FORMAT_BGR_SUPPORTED
+ int bgr = (image->format & PNG_FORMAT_FLAG_BGR) != 0 ? 2 : 0;
+# else
+# define bgr 0
+# endif
+
+ if (output_encoding == P_LINEAR)
+ {
+ png_uint_16p entry = png_voidcast(png_uint_16p, display->colormap);
+
+ entry += ip * PNG_IMAGE_SAMPLE_CHANNELS(image->format);
+
+ /* The linear 16-bit values must be pre-multiplied by the alpha channel
+ * value, if less than 65535 (this is, effectively, composite on black
+ * if the alpha channel is removed.)
+ */
+ switch (PNG_IMAGE_SAMPLE_CHANNELS(image->format))
+ {
+ case 4:
+ entry[afirst ? 0 : 3] = (png_uint_16)alpha;
+ /* FALLTHROUGH */
+
+ case 3:
+ if (alpha < 65535)
+ {
+ if (alpha > 0)
+ {
+ blue = (blue * alpha + 32767U)/65535U;
+ green = (green * alpha + 32767U)/65535U;
+ red = (red * alpha + 32767U)/65535U;
+ }
+
+ else
+ red = green = blue = 0;
+ }
+ entry[afirst + (2 ^ bgr)] = (png_uint_16)blue;
+ entry[afirst + 1] = (png_uint_16)green;
+ entry[afirst + bgr] = (png_uint_16)red;
+ break;
+
+ case 2:
+ entry[1 ^ afirst] = (png_uint_16)alpha;
+ /* FALLTHROUGH */
+
+ case 1:
+ if (alpha < 65535)
+ {
+ if (alpha > 0)
+ green = (green * alpha + 32767U)/65535U;
+
+ else
+ green = 0;
+ }
+ entry[afirst] = (png_uint_16)green;
+ break;
+
+ default:
+ break;
+ }
+ }
+
+ else /* output encoding is P_sRGB */
+ {
+ png_bytep entry = png_voidcast(png_bytep, display->colormap);
+
+ entry += ip * PNG_IMAGE_SAMPLE_CHANNELS(image->format);
+
+ switch (PNG_IMAGE_SAMPLE_CHANNELS(image->format))
+ {
+ case 4:
+ entry[afirst ? 0 : 3] = (png_byte)alpha;
+ /* FALLTHROUGH */
+ case 3:
+ entry[afirst + (2 ^ bgr)] = (png_byte)blue;
+ entry[afirst + 1] = (png_byte)green;
+ entry[afirst + bgr] = (png_byte)red;
+ break;
+
+ case 2:
+ entry[1 ^ afirst] = (png_byte)alpha;
+ /* FALLTHROUGH */
+ case 1:
+ entry[afirst] = (png_byte)green;
+ break;
+
+ default:
+ break;
+ }
+ }
+
+# ifdef afirst
+# undef afirst
+# endif
+# ifdef bgr
+# undef bgr
+# endif
+ }
+}
+
+static int
+make_gray_file_colormap(png_image_read_control *display)
+{
+ unsigned int i;
+
+ for (i=0; i<256; ++i)
+ png_create_colormap_entry(display, i, i, i, i, 255, P_FILE);
+
+ return (int)i;
+}
+
+static int
+make_gray_colormap(png_image_read_control *display)
+{
+ unsigned int i;
+
+ for (i=0; i<256; ++i)
+ png_create_colormap_entry(display, i, i, i, i, 255, P_sRGB);
+
+ return (int)i;
+}
+#define PNG_GRAY_COLORMAP_ENTRIES 256
+
+static int
+make_ga_colormap(png_image_read_control *display)
+{
+ unsigned int i, a;
+
+ /* Alpha is retained, the output will be a color-map with entries
+ * selected by six levels of alpha. One transparent entry, 6 gray
+ * levels for all the intermediate alpha values, leaving 230 entries
+ * for the opaque grays. The color-map entries are the six values
+ * [0..5]*51, the GA processing uses PNG_DIV51(value) to find the
+ * relevant entry.
+ *
+ * if (alpha > 229) // opaque
+ * {
+ * // The 231 entries are selected to make the math below work:
+ * base = 0;
+ * entry = (231 * gray + 128) >> 8;
+ * }
+ * else if (alpha < 26) // transparent
+ * {
+ * base = 231;
+ * entry = 0;
+ * }
+ * else // partially opaque
+ * {
+ * base = 226 + 6 * PNG_DIV51(alpha);
+ * entry = PNG_DIV51(gray);
+ * }
+ */
+ i = 0;
+ while (i < 231)
+ {
+ unsigned int gray = (i * 256 + 115) / 231;
+ png_create_colormap_entry(display, i++, gray, gray, gray, 255, P_sRGB);
+ }
+
+ /* 255 is used here for the component values for consistency with the code
+ * that undoes premultiplication in pngwrite.c.
+ */
+ png_create_colormap_entry(display, i++, 255, 255, 255, 0, P_sRGB);
+
+ for (a=1; a<5; ++a)
+ {
+ unsigned int g;
+
+ for (g=0; g<6; ++g)
+ png_create_colormap_entry(display, i++, g*51, g*51, g*51, a*51,
+ P_sRGB);
+ }
+
+ return (int)i;
+}
+
+#define PNG_GA_COLORMAP_ENTRIES 256
+
+static int
+make_rgb_colormap(png_image_read_control *display)
+{
+ unsigned int i, r;
+
+ /* Build a 6x6x6 opaque RGB cube */
+ for (i=r=0; r<6; ++r)
+ {
+ unsigned int g;
+
+ for (g=0; g<6; ++g)
+ {
+ unsigned int b;
+
+ for (b=0; b<6; ++b)
+ png_create_colormap_entry(display, i++, r*51, g*51, b*51, 255,
+ P_sRGB);
+ }
+ }
+
+ return (int)i;
+}
+
+#define PNG_RGB_COLORMAP_ENTRIES 216
+
+/* Return a palette index to the above palette given three 8-bit sRGB values. */
+#define PNG_RGB_INDEX(r,g,b) \
+ ((png_byte)(6 * (6 * PNG_DIV51(r) + PNG_DIV51(g)) + PNG_DIV51(b)))
+
+static int
+png_image_read_colormap(png_voidp argument)
+{
+ png_image_read_control *display =
+ png_voidcast(png_image_read_control*, argument);
+ png_imagep image = display->image;
+
+ png_structrp png_ptr = image->opaque->png_ptr;
+ png_uint_32 output_format = image->format;
+ int output_encoding = (output_format & PNG_FORMAT_FLAG_LINEAR) != 0 ?
+ P_LINEAR : P_sRGB;
+
+ unsigned int cmap_entries;
+ unsigned int output_processing; /* Output processing option */
+ unsigned int data_encoding = P_NOTSET; /* Encoding libpng must produce */
+
+ /* Background information; the background color and the index of this color
+ * in the color-map if it exists (else 256).
+ */
+ unsigned int background_index = 256;
+ png_uint_32 back_r, back_g, back_b;
+
+ /* Flags to accumulate things that need to be done to the input. */
+ int expand_tRNS = 0;
+
+ /* Exclude the NYI feature of compositing onto a color-mapped buffer; it is
+ * very difficult to do, the results look awful, and it is difficult to see
+ * what possible use it is because the application can't control the
+ * color-map.
+ */
+ if (((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0 ||
+ png_ptr->num_trans > 0) /* alpha in input */ &&
+ ((output_format & PNG_FORMAT_FLAG_ALPHA) == 0) /* no alpha in output */)
+ {
+ if (output_encoding == P_LINEAR) /* compose on black */
+ back_b = back_g = back_r = 0;
+
+ else if (display->background == NULL /* no way to remove it */)
+ png_error(png_ptr,
+ "background color must be supplied to remove alpha/transparency");
+
+ /* Get a copy of the background color (this avoids repeating the checks
+ * below.) The encoding is 8-bit sRGB or 16-bit linear, depending on the
+ * output format.
+ */
+ else
+ {
+ back_g = display->background->green;
+ if ((output_format & PNG_FORMAT_FLAG_COLOR) != 0)
+ {
+ back_r = display->background->red;
+ back_b = display->background->blue;
+ }
+ else
+ back_b = back_r = back_g;
+ }
+ }
+
+ else if (output_encoding == P_LINEAR)
+ back_b = back_r = back_g = 65535;
+
+ else
+ back_b = back_r = back_g = 255;
+
+ /* Default the input file gamma if required - this is necessary because
+ * libpng assumes that if no gamma information is present the data is in the
+ * output format, but the simplified API deduces the gamma from the input
+ * format. The 'default' gamma value is also set by png_set_alpha_mode, but
+ * this is happening before any such call, so:
+ *
+ * TODO: should be an internal API and all this code should be copied into a
+ * single common gamma+colorspace file.
+ */
+ if (png_ptr->bit_depth == 16 &&
+ (image->flags & PNG_IMAGE_FLAG_16BIT_sRGB) == 0)
+ png_ptr->default_gamma = PNG_GAMMA_LINEAR;
+
+ else
+ png_ptr->default_gamma = PNG_GAMMA_sRGB_INVERSE;
+
+ /* Decide what to do based on the PNG color type of the input data. The
+ * utility function png_create_colormap_entry deals with most aspects of the
+ * output transformations; this code works out how to produce bytes of
+ * color-map entries from the original format.
+ */
+ switch (png_ptr->color_type)
+ {
+ case PNG_COLOR_TYPE_GRAY:
+ if (png_ptr->bit_depth <= 8)
+ {
+ /* There at most 256 colors in the output, regardless of
+ * transparency.
+ */
+ unsigned int step, i, val, trans = 256/*ignore*/, back_alpha = 0;
+
+ cmap_entries = 1U << png_ptr->bit_depth;
+ if (cmap_entries > image->colormap_entries)
+ png_error(png_ptr, "gray[8] color-map: too few entries");
+
+ step = 255 / (cmap_entries - 1);
+ output_processing = PNG_CMAP_NONE;
+
+ /* If there is a tRNS chunk then this either selects a transparent
+ * value or, if the output has no alpha, the background color.
+ */
+ if (png_ptr->num_trans > 0)
+ {
+ trans = png_ptr->trans_color.gray;
+
+ if ((output_format & PNG_FORMAT_FLAG_ALPHA) == 0)
+ back_alpha = output_encoding == P_LINEAR ? 65535 : 255;
+ }
+
+ /* png_create_colormap_entry just takes an RGBA and writes the
+ * corresponding color-map entry using the format from 'image',
+ * including the required conversion to sRGB or linear as
+ * appropriate. The input values are always either sRGB (if the
+ * gamma correction flag is 0) or 0..255 scaled file encoded values
+ * (if the function must gamma correct them).
+ */
+ for (i=val=0; ibit_depth < 8)
+ png_set_packing(png_ptr);
+ }
+
+ else /* bit depth is 16 */
+ {
+ /* The 16-bit input values can be converted directly to 8-bit gamma
+ * encoded values; however, if a tRNS chunk is present 257 color-map
+ * entries are required. This means that the extra entry requires
+ * special processing; add an alpha channel, sacrifice gray level
+ * 254 and convert transparent (alpha==0) entries to that.
+ *
+ * Use libpng to chop the data to 8 bits. Convert it to sRGB at the
+ * same time to minimize quality loss. If a tRNS chunk is present
+ * this means libpng must handle it too; otherwise it is impossible
+ * to do the exact match on the 16-bit value.
+ *
+ * If the output has no alpha channel *and* the background color is
+ * gray then it is possible to let libpng handle the substitution by
+ * ensuring that the corresponding gray level matches the background
+ * color exactly.
+ */
+ data_encoding = P_sRGB;
+
+ if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries)
+ png_error(png_ptr, "gray[16] color-map: too few entries");
+
+ cmap_entries = (unsigned int)make_gray_colormap(display);
+
+ if (png_ptr->num_trans > 0)
+ {
+ unsigned int back_alpha;
+
+ if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ back_alpha = 0;
+
+ else
+ {
+ if (back_r == back_g && back_g == back_b)
+ {
+ /* Background is gray; no special processing will be
+ * required.
+ */
+ png_color_16 c;
+ png_uint_32 gray = back_g;
+
+ if (output_encoding == P_LINEAR)
+ {
+ gray = PNG_sRGB_FROM_LINEAR(gray * 255);
+
+ /* And make sure the corresponding palette entry
+ * matches.
+ */
+ png_create_colormap_entry(display, gray, back_g, back_g,
+ back_g, 65535, P_LINEAR);
+ }
+
+ /* The background passed to libpng, however, must be the
+ * sRGB value.
+ */
+ c.index = 0; /*unused*/
+ c.gray = c.red = c.green = c.blue = (png_uint_16)gray;
+
+ /* NOTE: does this work without expanding tRNS to alpha?
+ * It should be the color->gray case below apparently
+ * doesn't.
+ */
+ png_set_background_fixed(png_ptr, &c,
+ PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
+ 0/*gamma: not used*/);
+
+ output_processing = PNG_CMAP_NONE;
+ break;
+ }
+#ifdef __COVERITY__
+ /* Coverity claims that output_encoding cannot be 2 (P_LINEAR)
+ * here.
+ */
+ back_alpha = 255;
+#else
+ back_alpha = output_encoding == P_LINEAR ? 65535 : 255;
+#endif
+ }
+
+ /* output_processing means that the libpng-processed row will be
+ * 8-bit GA and it has to be processing to single byte color-map
+ * values. Entry 254 is replaced by either a completely
+ * transparent entry or by the background color at full
+ * precision (and the background color is not a simple gray
+ * level in this case.)
+ */
+ expand_tRNS = 1;
+ output_processing = PNG_CMAP_TRANS;
+ background_index = 254;
+
+ /* And set (overwrite) color-map entry 254 to the actual
+ * background color at full precision.
+ */
+ png_create_colormap_entry(display, 254, back_r, back_g, back_b,
+ back_alpha, output_encoding);
+ }
+
+ else
+ output_processing = PNG_CMAP_NONE;
+ }
+ break;
+
+ case PNG_COLOR_TYPE_GRAY_ALPHA:
+ /* 8-bit or 16-bit PNG with two channels - gray and alpha. A minimum
+ * of 65536 combinations. If, however, the alpha channel is to be
+ * removed there are only 256 possibilities if the background is gray.
+ * (Otherwise there is a subset of the 65536 possibilities defined by
+ * the triangle between black, white and the background color.)
+ *
+ * Reduce 16-bit files to 8-bit and sRGB encode the result. No need to
+ * worry about tRNS matching - tRNS is ignored if there is an alpha
+ * channel.
+ */
+ data_encoding = P_sRGB;
+
+ if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ {
+ if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries)
+ png_error(png_ptr, "gray+alpha color-map: too few entries");
+
+ cmap_entries = (unsigned int)make_ga_colormap(display);
+
+ background_index = PNG_CMAP_GA_BACKGROUND;
+ output_processing = PNG_CMAP_GA;
+ }
+
+ else /* alpha is removed */
+ {
+ /* Alpha must be removed as the PNG data is processed when the
+ * background is a color because the G and A channels are
+ * independent and the vector addition (non-parallel vectors) is a
+ * 2-D problem.
+ *
+ * This can be reduced to the same algorithm as above by making a
+ * colormap containing gray levels (for the opaque grays), a
+ * background entry (for a transparent pixel) and a set of four six
+ * level color values, one set for each intermediate alpha value.
+ * See the comments in make_ga_colormap for how this works in the
+ * per-pixel processing.
+ *
+ * If the background is gray, however, we only need a 256 entry gray
+ * level color map. It is sufficient to make the entry generated
+ * for the background color be exactly the color specified.
+ */
+ if ((output_format & PNG_FORMAT_FLAG_COLOR) == 0 ||
+ (back_r == back_g && back_g == back_b))
+ {
+ /* Background is gray; no special processing will be required. */
+ png_color_16 c;
+ png_uint_32 gray = back_g;
+
+ if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries)
+ png_error(png_ptr, "gray-alpha color-map: too few entries");
+
+ cmap_entries = (unsigned int)make_gray_colormap(display);
+
+ if (output_encoding == P_LINEAR)
+ {
+ gray = PNG_sRGB_FROM_LINEAR(gray * 255);
+
+ /* And make sure the corresponding palette entry matches. */
+ png_create_colormap_entry(display, gray, back_g, back_g,
+ back_g, 65535, P_LINEAR);
+ }
+
+ /* The background passed to libpng, however, must be the sRGB
+ * value.
+ */
+ c.index = 0; /*unused*/
+ c.gray = c.red = c.green = c.blue = (png_uint_16)gray;
+
+ png_set_background_fixed(png_ptr, &c,
+ PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
+ 0/*gamma: not used*/);
+
+ output_processing = PNG_CMAP_NONE;
+ }
+
+ else
+ {
+ png_uint_32 i, a;
+
+ /* This is the same as png_make_ga_colormap, above, except that
+ * the entries are all opaque.
+ */
+ if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries)
+ png_error(png_ptr, "ga-alpha color-map: too few entries");
+
+ i = 0;
+ while (i < 231)
+ {
+ png_uint_32 gray = (i * 256 + 115) / 231;
+ png_create_colormap_entry(display, i++, gray, gray, gray,
+ 255, P_sRGB);
+ }
+
+ /* NOTE: this preserves the full precision of the application
+ * background color.
+ */
+ background_index = i;
+ png_create_colormap_entry(display, i++, back_r, back_g, back_b,
+#ifdef __COVERITY__
+ /* Coverity claims that output_encoding
+ * cannot be 2 (P_LINEAR) here.
+ */ 255U,
+#else
+ output_encoding == P_LINEAR ? 65535U : 255U,
+#endif
+ output_encoding);
+
+ /* For non-opaque input composite on the sRGB background - this
+ * requires inverting the encoding for each component. The input
+ * is still converted to the sRGB encoding because this is a
+ * reasonable approximate to the logarithmic curve of human
+ * visual sensitivity, at least over the narrow range which PNG
+ * represents. Consequently 'G' is always sRGB encoded, while
+ * 'A' is linear. We need the linear background colors.
+ */
+ if (output_encoding == P_sRGB) /* else already linear */
+ {
+ /* This may produce a value not exactly matching the
+ * background, but that's ok because these numbers are only
+ * used when alpha != 0
+ */
+ back_r = png_sRGB_table[back_r];
+ back_g = png_sRGB_table[back_g];
+ back_b = png_sRGB_table[back_b];
+ }
+
+ for (a=1; a<5; ++a)
+ {
+ unsigned int g;
+
+ /* PNG_sRGB_FROM_LINEAR expects a 16-bit linear value scaled
+ * by an 8-bit alpha value (0..255).
+ */
+ png_uint_32 alpha = 51 * a;
+ png_uint_32 back_rx = (255-alpha) * back_r;
+ png_uint_32 back_gx = (255-alpha) * back_g;
+ png_uint_32 back_bx = (255-alpha) * back_b;
+
+ for (g=0; g<6; ++g)
+ {
+ png_uint_32 gray = png_sRGB_table[g*51] * alpha;
+
+ png_create_colormap_entry(display, i++,
+ PNG_sRGB_FROM_LINEAR(gray + back_rx),
+ PNG_sRGB_FROM_LINEAR(gray + back_gx),
+ PNG_sRGB_FROM_LINEAR(gray + back_bx), 255, P_sRGB);
+ }
+ }
+
+ cmap_entries = i;
+ output_processing = PNG_CMAP_GA;
+ }
+ }
+ break;
+
+ case PNG_COLOR_TYPE_RGB:
+ case PNG_COLOR_TYPE_RGB_ALPHA:
+ /* Exclude the case where the output is gray; we can always handle this
+ * with the cases above.
+ */
+ if ((output_format & PNG_FORMAT_FLAG_COLOR) == 0)
+ {
+ /* The color-map will be grayscale, so we may as well convert the
+ * input RGB values to a simple grayscale and use the grayscale
+ * code above.
+ *
+ * NOTE: calling this apparently damages the recognition of the
+ * transparent color in background color handling; call
+ * png_set_tRNS_to_alpha before png_set_background_fixed.
+ */
+ png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE, -1,
+ -1);
+ data_encoding = P_sRGB;
+
+ /* The output will now be one or two 8-bit gray or gray+alpha
+ * channels. The more complex case arises when the input has alpha.
+ */
+ if ((png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+ png_ptr->num_trans > 0) &&
+ (output_format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ {
+ /* Both input and output have an alpha channel, so no background
+ * processing is required; just map the GA bytes to the right
+ * color-map entry.
+ */
+ expand_tRNS = 1;
+
+ if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries)
+ png_error(png_ptr, "rgb[ga] color-map: too few entries");
+
+ cmap_entries = (unsigned int)make_ga_colormap(display);
+ background_index = PNG_CMAP_GA_BACKGROUND;
+ output_processing = PNG_CMAP_GA;
+ }
+
+ else
+ {
+ const png_fixed_point gamma = png_resolve_file_gamma(png_ptr);
+
+ /* Either the input or the output has no alpha channel, so there
+ * will be no non-opaque pixels in the color-map; it will just be
+ * grayscale.
+ */
+ if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries)
+ png_error(png_ptr, "rgb[gray] color-map: too few entries");
+
+ /* Ideally this code would use libpng to do the gamma correction,
+ * but if an input alpha channel is to be removed we will hit the
+ * libpng bug in gamma+compose+rgb-to-gray (the double gamma
+ * correction bug). Fix this by dropping the gamma correction in
+ * this case and doing it in the palette; this will result in
+ * duplicate palette entries, but that's better than the
+ * alternative of double gamma correction.
+ *
+ * NOTE: PNGv3: check the resolved result of all the potentially
+ * different colour space chunks.
+ */
+ if ((png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+ png_ptr->num_trans > 0) &&
+ png_gamma_not_sRGB(gamma) != 0)
+ {
+ cmap_entries = (unsigned int)make_gray_file_colormap(display);
+ data_encoding = P_FILE;
+ }
+
+ else
+ cmap_entries = (unsigned int)make_gray_colormap(display);
+
+ /* But if the input has alpha or transparency it must be removed
+ */
+ if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+ png_ptr->num_trans > 0)
+ {
+ png_color_16 c;
+ png_uint_32 gray = back_g;
+
+ /* We need to ensure that the application background exists in
+ * the colormap and that completely transparent pixels map to
+ * it. Achieve this simply by ensuring that the entry
+ * selected for the background really is the background color.
+ */
+ if (data_encoding == P_FILE) /* from the fixup above */
+ {
+ /* The app supplied a gray which is in output_encoding, we
+ * need to convert it to a value of the input (P_FILE)
+ * encoding then set this palette entry to the required
+ * output encoding.
+ */
+ if (output_encoding == P_sRGB)
+ gray = png_sRGB_table[gray]; /* now P_LINEAR */
+
+ gray = PNG_DIV257(png_gamma_16bit_correct(gray, gamma));
+ /* now P_FILE */
+
+ /* And make sure the corresponding palette entry contains
+ * exactly the required sRGB value.
+ */
+ png_create_colormap_entry(display, gray, back_g, back_g,
+ back_g, 0/*unused*/, output_encoding);
+ }
+
+ else if (output_encoding == P_LINEAR)
+ {
+ gray = PNG_sRGB_FROM_LINEAR(gray * 255);
+
+ /* And make sure the corresponding palette entry matches.
+ */
+ png_create_colormap_entry(display, gray, back_g, back_g,
+ back_g, 0/*unused*/, P_LINEAR);
+ }
+
+ /* The background passed to libpng, however, must be the
+ * output (normally sRGB) value.
+ */
+ c.index = 0; /*unused*/
+ c.gray = c.red = c.green = c.blue = (png_uint_16)gray;
+
+ /* NOTE: the following is apparently a bug in libpng. Without
+ * it the transparent color recognition in
+ * png_set_background_fixed seems to go wrong.
+ */
+ expand_tRNS = 1;
+ png_set_background_fixed(png_ptr, &c,
+ PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
+ 0/*gamma: not used*/);
+ }
+
+ output_processing = PNG_CMAP_NONE;
+ }
+ }
+
+ else /* output is color */
+ {
+ /* We could use png_quantize here so long as there is no transparent
+ * color or alpha; png_quantize ignores alpha. Easier overall just
+ * to do it once and using PNG_DIV51 on the 6x6x6 reduced RGB cube.
+ * Consequently we always want libpng to produce sRGB data.
+ */
+ data_encoding = P_sRGB;
+
+ /* Is there any transparency or alpha? */
+ if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+ png_ptr->num_trans > 0)
+ {
+ /* Is there alpha in the output too? If so all four channels are
+ * processed into a special RGB cube with alpha support.
+ */
+ if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ {
+ png_uint_32 r;
+
+ if (PNG_RGB_COLORMAP_ENTRIES+1+27 > image->colormap_entries)
+ png_error(png_ptr, "rgb+alpha color-map: too few entries");
+
+ cmap_entries = (unsigned int)make_rgb_colormap(display);
+
+ /* Add a transparent entry. */
+ png_create_colormap_entry(display, cmap_entries, 255, 255,
+ 255, 0, P_sRGB);
+
+ /* This is stored as the background index for the processing
+ * algorithm.
+ */
+ background_index = cmap_entries++;
+
+ /* Add 27 r,g,b entries each with alpha 0.5. */
+ for (r=0; r<256; r = (r << 1) | 0x7f)
+ {
+ png_uint_32 g;
+
+ for (g=0; g<256; g = (g << 1) | 0x7f)
+ {
+ png_uint_32 b;
+
+ /* This generates components with the values 0, 127 and
+ * 255
+ */
+ for (b=0; b<256; b = (b << 1) | 0x7f)
+ png_create_colormap_entry(display, cmap_entries++,
+ r, g, b, 128, P_sRGB);
+ }
+ }
+
+ expand_tRNS = 1;
+ output_processing = PNG_CMAP_RGB_ALPHA;
+ }
+
+ else
+ {
+ /* Alpha/transparency must be removed. The background must
+ * exist in the color map (achieved by setting adding it after
+ * the 666 color-map). If the standard processing code will
+ * pick up this entry automatically that's all that is
+ * required; libpng can be called to do the background
+ * processing.
+ */
+ unsigned int sample_size =
+ PNG_IMAGE_SAMPLE_SIZE(output_format);
+ png_uint_32 r, g, b; /* sRGB background */
+
+ if (PNG_RGB_COLORMAP_ENTRIES+1+27 > image->colormap_entries)
+ png_error(png_ptr, "rgb-alpha color-map: too few entries");
+
+ cmap_entries = (unsigned int)make_rgb_colormap(display);
+
+ png_create_colormap_entry(display, cmap_entries, back_r,
+ back_g, back_b, 0/*unused*/, output_encoding);
+
+ if (output_encoding == P_LINEAR)
+ {
+ r = PNG_sRGB_FROM_LINEAR(back_r * 255);
+ g = PNG_sRGB_FROM_LINEAR(back_g * 255);
+ b = PNG_sRGB_FROM_LINEAR(back_b * 255);
+ }
+
+ else
+ {
+ r = back_r;
+ g = back_g;
+ b = back_g;
+ }
+
+ /* Compare the newly-created color-map entry with the one the
+ * PNG_CMAP_RGB algorithm will use. If the two entries don't
+ * match, add the new one and set this as the background
+ * index.
+ */
+ if (memcmp((png_const_bytep)display->colormap +
+ sample_size * cmap_entries,
+ (png_const_bytep)display->colormap +
+ sample_size * PNG_RGB_INDEX(r,g,b),
+ sample_size) != 0)
+ {
+ /* The background color must be added. */
+ background_index = cmap_entries++;
+
+ /* Add 27 r,g,b entries each with created by composing with
+ * the background at alpha 0.5.
+ */
+ for (r=0; r<256; r = (r << 1) | 0x7f)
+ {
+ for (g=0; g<256; g = (g << 1) | 0x7f)
+ {
+ /* This generates components with the values 0, 127
+ * and 255
+ */
+ for (b=0; b<256; b = (b << 1) | 0x7f)
+ png_create_colormap_entry(display, cmap_entries++,
+ png_colormap_compose(display, r, P_sRGB, 128,
+ back_r, output_encoding),
+ png_colormap_compose(display, g, P_sRGB, 128,
+ back_g, output_encoding),
+ png_colormap_compose(display, b, P_sRGB, 128,
+ back_b, output_encoding),
+ 0/*unused*/, output_encoding);
+ }
+ }
+
+ expand_tRNS = 1;
+ output_processing = PNG_CMAP_RGB_ALPHA;
+ }
+
+ else /* background color is in the standard color-map */
+ {
+ png_color_16 c;
+
+ c.index = 0; /*unused*/
+ c.red = (png_uint_16)back_r;
+ c.gray = c.green = (png_uint_16)back_g;
+ c.blue = (png_uint_16)back_b;
+
+ png_set_background_fixed(png_ptr, &c,
+ PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
+ 0/*gamma: not used*/);
+
+ output_processing = PNG_CMAP_RGB;
+ }
+ }
+ }
+
+ else /* no alpha or transparency in the input */
+ {
+ /* Alpha in the output is irrelevant, simply map the opaque input
+ * pixels to the 6x6x6 color-map.
+ */
+ if (PNG_RGB_COLORMAP_ENTRIES > image->colormap_entries)
+ png_error(png_ptr, "rgb color-map: too few entries");
+
+ cmap_entries = (unsigned int)make_rgb_colormap(display);
+ output_processing = PNG_CMAP_RGB;
+ }
+ }
+ break;
+
+ case PNG_COLOR_TYPE_PALETTE:
+ /* It's already got a color-map. It may be necessary to eliminate the
+ * tRNS entries though.
+ */
+ {
+ unsigned int num_trans = png_ptr->num_trans;
+ png_const_bytep trans = num_trans > 0 ? png_ptr->trans_alpha : NULL;
+ png_const_colorp colormap = png_ptr->palette;
+ int do_background = trans != NULL &&
+ (output_format & PNG_FORMAT_FLAG_ALPHA) == 0;
+ unsigned int i;
+
+ /* Just in case: */
+ if (trans == NULL)
+ num_trans = 0;
+
+ output_processing = PNG_CMAP_NONE;
+ data_encoding = P_FILE; /* Don't change from color-map indices */
+ cmap_entries = (unsigned int)png_ptr->num_palette;
+ if (cmap_entries > 256)
+ cmap_entries = 256;
+
+ if (cmap_entries > (unsigned int)image->colormap_entries)
+ png_error(png_ptr, "palette color-map: too few entries");
+
+ for (i=0; i < cmap_entries; ++i)
+ {
+ if (do_background != 0 && i < num_trans && trans[i] < 255)
+ {
+ if (trans[i] == 0)
+ png_create_colormap_entry(display, i, back_r, back_g,
+ back_b, 0, output_encoding);
+
+ else
+ {
+ /* Must compose the PNG file color in the color-map entry
+ * on the sRGB color in 'back'.
+ */
+ png_create_colormap_entry(display, i,
+ png_colormap_compose(display, colormap[i].red,
+ P_FILE, trans[i], back_r, output_encoding),
+ png_colormap_compose(display, colormap[i].green,
+ P_FILE, trans[i], back_g, output_encoding),
+ png_colormap_compose(display, colormap[i].blue,
+ P_FILE, trans[i], back_b, output_encoding),
+ output_encoding == P_LINEAR ? trans[i] * 257U :
+ trans[i],
+ output_encoding);
+ }
+ }
+
+ else
+ png_create_colormap_entry(display, i, colormap[i].red,
+ colormap[i].green, colormap[i].blue,
+ i < num_trans ? trans[i] : 255U, P_FILE/*8-bit*/);
+ }
+
+ /* The PNG data may have indices packed in fewer than 8 bits, it
+ * must be expanded if so.
+ */
+ if (png_ptr->bit_depth < 8)
+ png_set_packing(png_ptr);
+ }
+ break;
+
+ default:
+ png_error(png_ptr, "invalid PNG color type");
+ /*NOT REACHED*/
+ }
+
+ /* Now deal with the output processing */
+ if (expand_tRNS != 0 && png_ptr->num_trans > 0 &&
+ (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) == 0)
+ png_set_tRNS_to_alpha(png_ptr);
+
+ switch (data_encoding)
+ {
+ case P_sRGB:
+ /* Change to 8-bit sRGB */
+ png_set_alpha_mode_fixed(png_ptr, PNG_ALPHA_PNG, PNG_GAMMA_sRGB);
+ /* FALLTHROUGH */
+
+ case P_FILE:
+ if (png_ptr->bit_depth > 8)
+ png_set_scale_16(png_ptr);
+ break;
+
+#ifdef __GNUC__
+ default:
+ png_error(png_ptr, "bad data option (internal error)");
+#endif
+ }
+
+ if (cmap_entries > 256 || cmap_entries > image->colormap_entries)
+ png_error(png_ptr, "color map overflow (BAD internal error)");
+
+ image->colormap_entries = cmap_entries;
+
+ /* Double check using the recorded background index */
+ switch (output_processing)
+ {
+ case PNG_CMAP_NONE:
+ if (background_index != PNG_CMAP_NONE_BACKGROUND)
+ goto bad_background;
+ break;
+
+ case PNG_CMAP_GA:
+ if (background_index != PNG_CMAP_GA_BACKGROUND)
+ goto bad_background;
+ break;
+
+ case PNG_CMAP_TRANS:
+ if (background_index >= cmap_entries ||
+ background_index != PNG_CMAP_TRANS_BACKGROUND)
+ goto bad_background;
+ break;
+
+ case PNG_CMAP_RGB:
+ if (background_index != PNG_CMAP_RGB_BACKGROUND)
+ goto bad_background;
+ break;
+
+ case PNG_CMAP_RGB_ALPHA:
+ if (background_index != PNG_CMAP_RGB_ALPHA_BACKGROUND)
+ goto bad_background;
+ break;
+
+ default:
+ png_error(png_ptr, "bad processing option (internal error)");
+
+ bad_background:
+ png_error(png_ptr, "bad background index (internal error)");
+ }
+
+ display->colormap_processing = (int)output_processing;
+
+ return 1/*ok*/;
+}
+
+/* The final part of the color-map read called from png_image_finish_read. */
+static int
+png_image_read_and_map(png_voidp argument)
+{
+ png_image_read_control *display = png_voidcast(png_image_read_control*,
+ argument);
+ png_imagep image = display->image;
+ png_structrp png_ptr = image->opaque->png_ptr;
+ int passes;
+
+ /* Called when the libpng data must be transformed into the color-mapped
+ * form. There is a local row buffer in display->local and this routine must
+ * do the interlace handling.
+ */
+ switch (png_ptr->interlaced)
+ {
+ case PNG_INTERLACE_NONE:
+ passes = 1;
+ break;
+
+ case PNG_INTERLACE_ADAM7:
+ passes = PNG_INTERLACE_ADAM7_PASSES;
+ break;
+
+ default:
+ png_error(png_ptr, "unknown interlace type");
+ }
+
+ {
+ png_uint_32 height = image->height;
+ png_uint_32 width = image->width;
+ int proc = display->colormap_processing;
+ png_bytep first_row = png_voidcast(png_bytep, display->first_row);
+ ptrdiff_t step_row = display->row_bytes;
+ int pass;
+
+ for (pass = 0; pass < passes; ++pass)
+ {
+ unsigned int startx, stepx, stepy;
+ png_uint_32 y;
+
+ if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
+ {
+ /* The row may be empty for a short image: */
+ if (PNG_PASS_COLS(width, pass) == 0)
+ continue;
+
+ startx = PNG_PASS_START_COL(pass);
+ stepx = PNG_PASS_COL_OFFSET(pass);
+ y = PNG_PASS_START_ROW(pass);
+ stepy = PNG_PASS_ROW_OFFSET(pass);
+ }
+
+ else
+ {
+ y = 0;
+ startx = 0;
+ stepx = stepy = 1;
+ }
+
+ for (; ylocal_row);
+ png_bytep outrow = first_row + y * step_row;
+ png_const_bytep end_row = outrow + width;
+
+ /* Read read the libpng data into the temporary buffer. */
+ png_read_row(png_ptr, inrow, NULL);
+
+ /* Now process the row according to the processing option, note
+ * that the caller verifies that the format of the libpng output
+ * data is as required.
+ */
+ outrow += startx;
+ switch (proc)
+ {
+ case PNG_CMAP_GA:
+ for (; outrow < end_row; outrow += stepx)
+ {
+ /* The data is always in the PNG order */
+ unsigned int gray = *inrow++;
+ unsigned int alpha = *inrow++;
+ unsigned int entry;
+
+ /* NOTE: this code is copied as a comment in
+ * make_ga_colormap above. Please update the
+ * comment if you change this code!
+ */
+ if (alpha > 229) /* opaque */
+ {
+ entry = (231 * gray + 128) >> 8;
+ }
+ else if (alpha < 26) /* transparent */
+ {
+ entry = 231;
+ }
+ else /* partially opaque */
+ {
+ entry = 226 + 6 * PNG_DIV51(alpha) + PNG_DIV51(gray);
+ }
+
+ *outrow = (png_byte)entry;
+ }
+ break;
+
+ case PNG_CMAP_TRANS:
+ for (; outrow < end_row; outrow += stepx)
+ {
+ png_byte gray = *inrow++;
+ png_byte alpha = *inrow++;
+
+ if (alpha == 0)
+ *outrow = PNG_CMAP_TRANS_BACKGROUND;
+
+ else if (gray != PNG_CMAP_TRANS_BACKGROUND)
+ *outrow = gray;
+
+ else
+ *outrow = (png_byte)(PNG_CMAP_TRANS_BACKGROUND+1);
+ }
+ break;
+
+ case PNG_CMAP_RGB:
+ for (; outrow < end_row; outrow += stepx)
+ {
+ *outrow = PNG_RGB_INDEX(inrow[0], inrow[1], inrow[2]);
+ inrow += 3;
+ }
+ break;
+
+ case PNG_CMAP_RGB_ALPHA:
+ for (; outrow < end_row; outrow += stepx)
+ {
+ unsigned int alpha = inrow[3];
+
+ /* Because the alpha entries only hold alpha==0.5 values
+ * split the processing at alpha==0.25 (64) and 0.75
+ * (196).
+ */
+
+ if (alpha >= 196)
+ *outrow = PNG_RGB_INDEX(inrow[0], inrow[1],
+ inrow[2]);
+
+ else if (alpha < 64)
+ *outrow = PNG_CMAP_RGB_ALPHA_BACKGROUND;
+
+ else
+ {
+ /* Likewise there are three entries for each of r, g
+ * and b. We could select the entry by popcount on
+ * the top two bits on those architectures that
+ * support it, this is what the code below does,
+ * crudely.
+ */
+ unsigned int back_i = PNG_CMAP_RGB_ALPHA_BACKGROUND+1;
+
+ /* Here are how the values map:
+ *
+ * 0x00 .. 0x3f -> 0
+ * 0x40 .. 0xbf -> 1
+ * 0xc0 .. 0xff -> 2
+ *
+ * So, as above with the explicit alpha checks, the
+ * breakpoints are at 64 and 196.
+ */
+ if (inrow[0] & 0x80) back_i += 9; /* red */
+ if (inrow[0] & 0x40) back_i += 9;
+ if (inrow[0] & 0x80) back_i += 3; /* green */
+ if (inrow[0] & 0x40) back_i += 3;
+ if (inrow[0] & 0x80) back_i += 1; /* blue */
+ if (inrow[0] & 0x40) back_i += 1;
+
+ *outrow = (png_byte)back_i;
+ }
+
+ inrow += 4;
+ }
+ break;
+
+ default:
+ break;
+ }
+ }
+ }
+ }
+
+ return 1;
+}
+
+static int
+png_image_read_colormapped(png_voidp argument)
+{
+ png_image_read_control *display = png_voidcast(png_image_read_control*,
+ argument);
+ png_imagep image = display->image;
+ png_controlp control = image->opaque;
+ png_structrp png_ptr = control->png_ptr;
+ png_inforp info_ptr = control->info_ptr;
+
+ int passes = 0; /* As a flag */
+
+ PNG_SKIP_CHUNKS(png_ptr);
+
+ /* Update the 'info' structure and make sure the result is as required; first
+ * make sure to turn on the interlace handling if it will be required
+ * (because it can't be turned on *after* the call to png_read_update_info!)
+ */
+ if (display->colormap_processing == PNG_CMAP_NONE)
+ passes = png_set_interlace_handling(png_ptr);
+
+ png_read_update_info(png_ptr, info_ptr);
+
+ /* The expected output can be deduced from the colormap_processing option. */
+ switch (display->colormap_processing)
+ {
+ case PNG_CMAP_NONE:
+ /* Output must be one channel and one byte per pixel, the output
+ * encoding can be anything.
+ */
+ if ((info_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
+ info_ptr->color_type == PNG_COLOR_TYPE_GRAY) &&
+ info_ptr->bit_depth == 8)
+ break;
+
+ goto bad_output;
+
+ case PNG_CMAP_TRANS:
+ case PNG_CMAP_GA:
+ /* Output must be two channels and the 'G' one must be sRGB, the latter
+ * can be checked with an exact number because it should have been set
+ * to this number above!
+ */
+ if (info_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
+ info_ptr->bit_depth == 8 &&
+ png_ptr->screen_gamma == PNG_GAMMA_sRGB &&
+ image->colormap_entries == 256)
+ break;
+
+ goto bad_output;
+
+ case PNG_CMAP_RGB:
+ /* Output must be 8-bit sRGB encoded RGB */
+ if (info_ptr->color_type == PNG_COLOR_TYPE_RGB &&
+ info_ptr->bit_depth == 8 &&
+ png_ptr->screen_gamma == PNG_GAMMA_sRGB &&
+ image->colormap_entries == 216)
+ break;
+
+ goto bad_output;
+
+ case PNG_CMAP_RGB_ALPHA:
+ /* Output must be 8-bit sRGB encoded RGBA */
+ if (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
+ info_ptr->bit_depth == 8 &&
+ png_ptr->screen_gamma == PNG_GAMMA_sRGB &&
+ image->colormap_entries == 244 /* 216 + 1 + 27 */)
+ break;
+
+ goto bad_output;
+
+ default:
+ bad_output:
+ png_error(png_ptr, "bad color-map processing (internal error)");
+ }
+
+ /* Now read the rows. Do this here if it is possible to read directly into
+ * the output buffer, otherwise allocate a local row buffer of the maximum
+ * size libpng requires and call the relevant processing routine safely.
+ */
+ {
+ png_voidp first_row = display->buffer;
+ ptrdiff_t row_bytes = display->row_stride;
+
+ /* The following expression is designed to work correctly whether it gives
+ * a signed or an unsigned result.
+ */
+ if (row_bytes < 0)
+ {
+ char *ptr = png_voidcast(char*, first_row);
+ ptr += (image->height-1) * (-row_bytes);
+ first_row = png_voidcast(png_voidp, ptr);
+ }
+
+ display->first_row = first_row;
+ display->row_bytes = row_bytes;
+ }
+
+ if (passes == 0)
+ {
+ int result;
+ png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr));
+
+ display->local_row = row;
+ result = png_safe_execute(image, png_image_read_and_map, display);
+ display->local_row = NULL;
+ png_free(png_ptr, row);
+
+ return result;
+ }
+
+ else
+ {
+ png_alloc_size_t row_bytes = (png_alloc_size_t)display->row_bytes;
+
+ while (--passes >= 0)
+ {
+ png_uint_32 y = image->height;
+ png_bytep row = png_voidcast(png_bytep, display->first_row);
+
+ for (; y > 0; --y)
+ {
+ png_read_row(png_ptr, row, NULL);
+ row += row_bytes;
+ }
+ }
+
+ return 1;
+ }
+}
+
+/* Just the row reading part of png_image_read. */
+static int
+png_image_read_composite(png_voidp argument)
+{
+ png_image_read_control *display = png_voidcast(png_image_read_control*,
+ argument);
+ png_imagep image = display->image;
+ png_structrp png_ptr = image->opaque->png_ptr;
+ int passes;
+
+ switch (png_ptr->interlaced)
+ {
+ case PNG_INTERLACE_NONE:
+ passes = 1;
+ break;
+
+ case PNG_INTERLACE_ADAM7:
+ passes = PNG_INTERLACE_ADAM7_PASSES;
+ break;
+
+ default:
+ png_error(png_ptr, "unknown interlace type");
+ }
+
+ {
+ png_uint_32 height = image->height;
+ png_uint_32 width = image->width;
+ ptrdiff_t step_row = display->row_bytes;
+ unsigned int channels =
+ (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1;
+ int pass;
+
+ for (pass = 0; pass < passes; ++pass)
+ {
+ unsigned int startx, stepx, stepy;
+ png_uint_32 y;
+
+ if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
+ {
+ /* The row may be empty for a short image: */
+ if (PNG_PASS_COLS(width, pass) == 0)
+ continue;
+
+ startx = PNG_PASS_START_COL(pass) * channels;
+ stepx = PNG_PASS_COL_OFFSET(pass) * channels;
+ y = PNG_PASS_START_ROW(pass);
+ stepy = PNG_PASS_ROW_OFFSET(pass);
+ }
+
+ else
+ {
+ y = 0;
+ startx = 0;
+ stepx = channels;
+ stepy = 1;
+ }
+
+ for (; ylocal_row);
+ png_bytep outrow;
+ png_const_bytep end_row;
+
+ /* Read the row, which is packed: */
+ png_read_row(png_ptr, inrow, NULL);
+
+ outrow = png_voidcast(png_bytep, display->first_row);
+ outrow += y * step_row;
+ end_row = outrow + width * channels;
+
+ /* Now do the composition on each pixel in this row. */
+ outrow += startx;
+ for (; outrow < end_row; outrow += stepx)
+ {
+ png_byte alpha = inrow[channels];
+
+ if (alpha > 0) /* else no change to the output */
+ {
+ unsigned int c;
+
+ for (c=0; cimage;
+ png_structrp png_ptr = image->opaque->png_ptr;
+ png_inforp info_ptr = image->opaque->info_ptr;
+ png_uint_32 height = image->height;
+ png_uint_32 width = image->width;
+ int pass, passes;
+
+ /* Double check the convoluted logic below. We expect to get here with
+ * libpng doing rgb to gray and gamma correction but background processing
+ * left to the png_image_read_background function. The rows libpng produce
+ * might be 8 or 16-bit but should always have two channels; gray plus alpha.
+ */
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == 0)
+ png_error(png_ptr, "lost rgb to gray");
+
+ if ((png_ptr->transformations & PNG_COMPOSE) != 0)
+ png_error(png_ptr, "unexpected compose");
+
+ if (png_get_channels(png_ptr, info_ptr) != 2)
+ png_error(png_ptr, "lost/gained channels");
+
+ /* Expect the 8-bit case to always remove the alpha channel */
+ if ((image->format & PNG_FORMAT_FLAG_LINEAR) == 0 &&
+ (image->format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ png_error(png_ptr, "unexpected 8-bit transformation");
+
+ switch (png_ptr->interlaced)
+ {
+ case PNG_INTERLACE_NONE:
+ passes = 1;
+ break;
+
+ case PNG_INTERLACE_ADAM7:
+ passes = PNG_INTERLACE_ADAM7_PASSES;
+ break;
+
+ default:
+ png_error(png_ptr, "unknown interlace type");
+ }
+
+ /* Use direct access to info_ptr here because otherwise the simplified API
+ * would require PNG_EASY_ACCESS_SUPPORTED (just for this.) Note this is
+ * checking the value after libpng expansions, not the original value in the
+ * PNG.
+ */
+ switch (info_ptr->bit_depth)
+ {
+ case 8:
+ /* 8-bit sRGB gray values with an alpha channel; the alpha channel is
+ * to be removed by composing on a background: either the row if
+ * display->background is NULL or display->background->green if not.
+ * Unlike the code above ALPHA_OPTIMIZED has *not* been done.
+ */
+ {
+ png_bytep first_row = png_voidcast(png_bytep, display->first_row);
+ ptrdiff_t step_row = display->row_bytes;
+
+ for (pass = 0; pass < passes; ++pass)
+ {
+ unsigned int startx, stepx, stepy;
+ png_uint_32 y;
+
+ if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
+ {
+ /* The row may be empty for a short image: */
+ if (PNG_PASS_COLS(width, pass) == 0)
+ continue;
+
+ startx = PNG_PASS_START_COL(pass);
+ stepx = PNG_PASS_COL_OFFSET(pass);
+ y = PNG_PASS_START_ROW(pass);
+ stepy = PNG_PASS_ROW_OFFSET(pass);
+ }
+
+ else
+ {
+ y = 0;
+ startx = 0;
+ stepx = stepy = 1;
+ }
+
+ if (display->background == NULL)
+ {
+ for (; ylocal_row);
+ png_bytep outrow = first_row + y * step_row;
+ png_const_bytep end_row = outrow + width;
+
+ /* Read the row, which is packed: */
+ png_read_row(png_ptr, inrow, NULL);
+
+ /* Now do the composition on each pixel in this row. */
+ outrow += startx;
+ for (; outrow < end_row; outrow += stepx)
+ {
+ png_byte alpha = inrow[1];
+
+ if (alpha > 0) /* else no change to the output */
+ {
+ png_uint_32 component = inrow[0];
+
+ if (alpha < 255) /* else just use component */
+ {
+ /* Since PNG_OPTIMIZED_ALPHA was not set it is
+ * necessary to invert the sRGB transfer
+ * function and multiply the alpha out.
+ */
+ component = png_sRGB_table[component] * alpha;
+ component += png_sRGB_table[outrow[0]] *
+ (255-alpha);
+ component = PNG_sRGB_FROM_LINEAR(component);
+ }
+
+ outrow[0] = (png_byte)component;
+ }
+
+ inrow += 2; /* gray and alpha channel */
+ }
+ }
+ }
+
+ else /* constant background value */
+ {
+ png_byte background8 = display->background->green;
+ png_uint_16 background = png_sRGB_table[background8];
+
+ for (; ylocal_row);
+ png_bytep outrow = first_row + y * step_row;
+ png_const_bytep end_row = outrow + width;
+
+ /* Read the row, which is packed: */
+ png_read_row(png_ptr, inrow, NULL);
+
+ /* Now do the composition on each pixel in this row. */
+ outrow += startx;
+ for (; outrow < end_row; outrow += stepx)
+ {
+ png_byte alpha = inrow[1];
+
+ if (alpha > 0) /* else use background */
+ {
+ png_uint_32 component = inrow[0];
+
+ if (alpha < 255) /* else just use component */
+ {
+ component = png_sRGB_table[component] * alpha;
+ component += background * (255-alpha);
+ component = PNG_sRGB_FROM_LINEAR(component);
+ }
+
+ outrow[0] = (png_byte)component;
+ }
+
+ else
+ outrow[0] = background8;
+
+ inrow += 2; /* gray and alpha channel */
+ }
+ }
+ }
+ }
+ }
+ break;
+
+ case 16:
+ /* 16-bit linear with pre-multiplied alpha; the pre-multiplication must
+ * still be done and, maybe, the alpha channel removed. This code also
+ * handles the alpha-first option.
+ */
+ {
+ png_uint_16p first_row = png_voidcast(png_uint_16p,
+ display->first_row);
+ /* The division by two is safe because the caller passed in a
+ * stride which was multiplied by 2 (below) to get row_bytes.
+ */
+ ptrdiff_t step_row = display->row_bytes / 2;
+ unsigned int preserve_alpha = (image->format &
+ PNG_FORMAT_FLAG_ALPHA) != 0;
+ unsigned int outchannels = 1U+preserve_alpha;
+ int swap_alpha = 0;
+
+# ifdef PNG_SIMPLIFIED_READ_AFIRST_SUPPORTED
+ if (preserve_alpha != 0 &&
+ (image->format & PNG_FORMAT_FLAG_AFIRST) != 0)
+ swap_alpha = 1;
+# endif
+
+ for (pass = 0; pass < passes; ++pass)
+ {
+ unsigned int startx, stepx, stepy;
+ png_uint_32 y;
+
+ /* The 'x' start and step are adjusted to output components here.
+ */
+ if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
+ {
+ /* The row may be empty for a short image: */
+ if (PNG_PASS_COLS(width, pass) == 0)
+ continue;
+
+ startx = PNG_PASS_START_COL(pass) * outchannels;
+ stepx = PNG_PASS_COL_OFFSET(pass) * outchannels;
+ y = PNG_PASS_START_ROW(pass);
+ stepy = PNG_PASS_ROW_OFFSET(pass);
+ }
+
+ else
+ {
+ y = 0;
+ startx = 0;
+ stepx = outchannels;
+ stepy = 1;
+ }
+
+ for (; ylocal_row), NULL);
+ inrow = png_voidcast(png_const_uint_16p, display->local_row);
+
+ /* Now do the pre-multiplication on each pixel in this row.
+ */
+ outrow += startx;
+ for (; outrow < end_row; outrow += stepx)
+ {
+ png_uint_32 component = inrow[0];
+ png_uint_16 alpha = inrow[1];
+
+ if (alpha > 0) /* else 0 */
+ {
+ if (alpha < 65535) /* else just use component */
+ {
+ component *= alpha;
+ component += 32767;
+ component /= 65535;
+ }
+ }
+
+ else
+ component = 0;
+
+ outrow[swap_alpha] = (png_uint_16)component;
+ if (preserve_alpha != 0)
+ outrow[1 ^ swap_alpha] = alpha;
+
+ inrow += 2; /* components and alpha channel */
+ }
+ }
+ }
+ }
+ break;
+
+#ifdef __GNUC__
+ default:
+ png_error(png_ptr, "unexpected bit depth");
+#endif
+ }
+
+ return 1;
+}
+
+/* The guts of png_image_finish_read as a png_safe_execute callback. */
+static int
+png_image_read_direct(png_voidp argument)
+{
+ png_image_read_control *display = png_voidcast(png_image_read_control*,
+ argument);
+ png_imagep image = display->image;
+ png_structrp png_ptr = image->opaque->png_ptr;
+ png_inforp info_ptr = image->opaque->info_ptr;
+
+ png_uint_32 format = image->format;
+ int linear = (format & PNG_FORMAT_FLAG_LINEAR) != 0;
+ int do_local_compose = 0;
+ int do_local_background = 0; /* to avoid double gamma correction bug */
+ int passes = 0;
+
+ /* Add transforms to ensure the correct output format is produced then check
+ * that the required implementation support is there. Always expand; always
+ * need 8 bits minimum, no palette and expanded tRNS.
+ */
+ png_set_expand(png_ptr);
+
+ /* Now check the format to see if it was modified. */
+ {
+ png_uint_32 base_format = png_image_format(png_ptr) &
+ ~PNG_FORMAT_FLAG_COLORMAP /* removed by png_set_expand */;
+ png_uint_32 change = format ^ base_format;
+ png_fixed_point output_gamma;
+ int mode; /* alpha mode */
+
+ /* Do this first so that we have a record if rgb to gray is happening. */
+ if ((change & PNG_FORMAT_FLAG_COLOR) != 0)
+ {
+ /* gray<->color transformation required. */
+ if ((format & PNG_FORMAT_FLAG_COLOR) != 0)
+ png_set_gray_to_rgb(png_ptr);
+
+ else
+ {
+ /* libpng can't do both rgb to gray and
+ * background/pre-multiplication if there is also significant gamma
+ * correction, because both operations require linear colors and
+ * the code only supports one transform doing the gamma correction.
+ * Handle this by doing the pre-multiplication or background
+ * operation in this code, if necessary.
+ *
+ * TODO: fix this by rewriting pngrtran.c (!)
+ *
+ * For the moment (given that fixing this in pngrtran.c is an
+ * enormous change) 'do_local_background' is used to indicate that
+ * the problem exists.
+ */
+ if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ do_local_background = 1/*maybe*/;
+
+ png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE,
+ PNG_RGB_TO_GRAY_DEFAULT, PNG_RGB_TO_GRAY_DEFAULT);
+ }
+
+ change &= ~PNG_FORMAT_FLAG_COLOR;
+ }
+
+ /* Set the gamma appropriately, linear for 16-bit input, sRGB otherwise.
+ */
+ {
+ /* This is safe but should no longer be necessary as
+ * png_ptr->default_gamma should have been set after the
+ * info-before-IDAT was read in png_image_read_header.
+ *
+ * TODO: 1.8: remove this and see what happens.
+ */
+ png_fixed_point input_gamma_default;
+
+ if ((base_format & PNG_FORMAT_FLAG_LINEAR) != 0 &&
+ (image->flags & PNG_IMAGE_FLAG_16BIT_sRGB) == 0)
+ input_gamma_default = PNG_GAMMA_LINEAR;
+ else
+ input_gamma_default = PNG_DEFAULT_sRGB;
+
+ /* Call png_set_alpha_mode to set the default for the input gamma; the
+ * output gamma is set by a second call below.
+ */
+ png_set_alpha_mode_fixed(png_ptr, PNG_ALPHA_PNG, input_gamma_default);
+ }
+
+ if (linear != 0)
+ {
+ /* If there *is* an alpha channel in the input it must be multiplied
+ * out; use PNG_ALPHA_STANDARD, otherwise just use PNG_ALPHA_PNG.
+ */
+ if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ mode = PNG_ALPHA_STANDARD; /* associated alpha */
+
+ else
+ mode = PNG_ALPHA_PNG;
+
+ output_gamma = PNG_GAMMA_LINEAR;
+ }
+
+ else
+ {
+ mode = PNG_ALPHA_PNG;
+ output_gamma = PNG_DEFAULT_sRGB;
+ }
+
+ if ((change & PNG_FORMAT_FLAG_ASSOCIATED_ALPHA) != 0)
+ {
+ mode = PNG_ALPHA_OPTIMIZED;
+ change &= ~PNG_FORMAT_FLAG_ASSOCIATED_ALPHA;
+ }
+
+ /* If 'do_local_background' is set check for the presence of gamma
+ * correction; this is part of the work-round for the libpng bug
+ * described above.
+ *
+ * TODO: fix libpng and remove this.
+ */
+ if (do_local_background != 0)
+ {
+ png_fixed_point gtest;
+
+ /* This is 'png_gamma_threshold' from pngrtran.c; the test used for
+ * gamma correction, the screen gamma hasn't been set on png_struct
+ * yet; it's set below. png_struct::gamma, however, is set to the
+ * final value.
+ */
+ if (png_muldiv(>est, output_gamma,
+ png_resolve_file_gamma(png_ptr), PNG_FP_1) != 0 &&
+ png_gamma_significant(gtest) == 0)
+ do_local_background = 0;
+
+ else if (mode == PNG_ALPHA_STANDARD)
+ {
+ do_local_background = 2/*required*/;
+ mode = PNG_ALPHA_PNG; /* prevent libpng doing it */
+ }
+
+ /* else leave as 1 for the checks below */
+ }
+
+ /* If the bit-depth changes then handle that here. */
+ if ((change & PNG_FORMAT_FLAG_LINEAR) != 0)
+ {
+ if (linear != 0 /*16-bit output*/)
+ png_set_expand_16(png_ptr);
+
+ else /* 8-bit output */
+ png_set_scale_16(png_ptr);
+
+ change &= ~PNG_FORMAT_FLAG_LINEAR;
+ }
+
+ /* Now the background/alpha channel changes. */
+ if ((change & PNG_FORMAT_FLAG_ALPHA) != 0)
+ {
+ /* Removing an alpha channel requires composition for the 8-bit
+ * formats; for the 16-bit it is already done, above, by the
+ * pre-multiplication and the channel just needs to be stripped.
+ */
+ if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ {
+ /* If RGB->gray is happening the alpha channel must be left and the
+ * operation completed locally.
+ *
+ * TODO: fix libpng and remove this.
+ */
+ if (do_local_background != 0)
+ do_local_background = 2/*required*/;
+
+ /* 16-bit output: just remove the channel */
+ else if (linear != 0) /* compose on black (well, pre-multiply) */
+ png_set_strip_alpha(png_ptr);
+
+ /* 8-bit output: do an appropriate compose */
+ else if (display->background != NULL)
+ {
+ png_color_16 c;
+
+ c.index = 0; /*unused*/
+ c.red = display->background->red;
+ c.green = display->background->green;
+ c.blue = display->background->blue;
+ c.gray = display->background->green;
+
+ /* This is always an 8-bit sRGB value, using the 'green' channel
+ * for gray is much better than calculating the luminance here;
+ * we can get off-by-one errors in that calculation relative to
+ * the app expectations and that will show up in transparent
+ * pixels.
+ */
+ png_set_background_fixed(png_ptr, &c,
+ PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
+ 0/*gamma: not used*/);
+ }
+
+ else /* compose on row: implemented below. */
+ {
+ do_local_compose = 1;
+ /* This leaves the alpha channel in the output, so it has to be
+ * removed by the code below. Set the encoding to the 'OPTIMIZE'
+ * one so the code only has to hack on the pixels that require
+ * composition.
+ */
+ mode = PNG_ALPHA_OPTIMIZED;
+ }
+ }
+
+ else /* output needs an alpha channel */
+ {
+ /* This is tricky because it happens before the swap operation has
+ * been accomplished; however, the swap does *not* swap the added
+ * alpha channel (weird API), so it must be added in the correct
+ * place.
+ */
+ png_uint_32 filler; /* opaque filler */
+ int where;
+
+ if (linear != 0)
+ filler = 65535;
+
+ else
+ filler = 255;
+
+#ifdef PNG_FORMAT_AFIRST_SUPPORTED
+ if ((format & PNG_FORMAT_FLAG_AFIRST) != 0)
+ {
+ where = PNG_FILLER_BEFORE;
+ change &= ~PNG_FORMAT_FLAG_AFIRST;
+ }
+
+ else
+#endif
+ where = PNG_FILLER_AFTER;
+
+ png_set_add_alpha(png_ptr, filler, where);
+ }
+
+ /* This stops the (irrelevant) call to swap_alpha below. */
+ change &= ~PNG_FORMAT_FLAG_ALPHA;
+ }
+
+ /* Now set the alpha mode correctly; this is always done, even if there is
+ * no alpha channel in either the input or the output because it correctly
+ * sets the output gamma.
+ */
+ png_set_alpha_mode_fixed(png_ptr, mode, output_gamma);
+
+# ifdef PNG_FORMAT_BGR_SUPPORTED
+ if ((change & PNG_FORMAT_FLAG_BGR) != 0)
+ {
+ /* Check only the output format; PNG is never BGR; don't do this if
+ * the output is gray, but fix up the 'format' value in that case.
+ */
+ if ((format & PNG_FORMAT_FLAG_COLOR) != 0)
+ png_set_bgr(png_ptr);
+
+ else
+ format &= ~PNG_FORMAT_FLAG_BGR;
+
+ change &= ~PNG_FORMAT_FLAG_BGR;
+ }
+# endif
+
+# ifdef PNG_FORMAT_AFIRST_SUPPORTED
+ if ((change & PNG_FORMAT_FLAG_AFIRST) != 0)
+ {
+ /* Only relevant if there is an alpha channel - it's particularly
+ * important to handle this correctly because do_local_compose may
+ * be set above and then libpng will keep the alpha channel for this
+ * code to remove.
+ */
+ if ((format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ {
+ /* Disable this if doing a local background,
+ * TODO: remove this when local background is no longer required.
+ */
+ if (do_local_background != 2)
+ png_set_swap_alpha(png_ptr);
+ }
+
+ else
+ format &= ~PNG_FORMAT_FLAG_AFIRST;
+
+ change &= ~PNG_FORMAT_FLAG_AFIRST;
+ }
+# endif
+
+ /* If the *output* is 16-bit then we need to check for a byte-swap on this
+ * architecture.
+ */
+ if (linear != 0)
+ {
+ png_uint_16 le = 0x0001;
+
+ if ((*(png_const_bytep) & le) != 0)
+ png_set_swap(png_ptr);
+ }
+
+ /* If change is not now 0 some transformation is missing - error out. */
+ if (change != 0)
+ png_error(png_ptr, "png_read_image: unsupported transformation");
+ }
+
+ PNG_SKIP_CHUNKS(png_ptr);
+
+ /* Update the 'info' structure and make sure the result is as required; first
+ * make sure to turn on the interlace handling if it will be required
+ * (because it can't be turned on *after* the call to png_read_update_info!)
+ *
+ * TODO: remove the do_local_background fixup below.
+ */
+ if (do_local_compose == 0 && do_local_background != 2)
+ passes = png_set_interlace_handling(png_ptr);
+
+ png_read_update_info(png_ptr, info_ptr);
+
+ {
+ png_uint_32 info_format = 0;
+
+ if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ info_format |= PNG_FORMAT_FLAG_COLOR;
+
+ if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+ {
+ /* do_local_compose removes this channel below. */
+ if (do_local_compose == 0)
+ {
+ /* do_local_background does the same if required. */
+ if (do_local_background != 2 ||
+ (format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ info_format |= PNG_FORMAT_FLAG_ALPHA;
+ }
+ }
+
+ else if (do_local_compose != 0) /* internal error */
+ png_error(png_ptr, "png_image_read: alpha channel lost");
+
+ if ((format & PNG_FORMAT_FLAG_ASSOCIATED_ALPHA) != 0) {
+ info_format |= PNG_FORMAT_FLAG_ASSOCIATED_ALPHA;
+ }
+
+ if (info_ptr->bit_depth == 16)
+ info_format |= PNG_FORMAT_FLAG_LINEAR;
+
+#ifdef PNG_FORMAT_BGR_SUPPORTED
+ if ((png_ptr->transformations & PNG_BGR) != 0)
+ info_format |= PNG_FORMAT_FLAG_BGR;
+#endif
+
+#ifdef PNG_FORMAT_AFIRST_SUPPORTED
+ if (do_local_background == 2)
+ {
+ if ((format & PNG_FORMAT_FLAG_AFIRST) != 0)
+ info_format |= PNG_FORMAT_FLAG_AFIRST;
+ }
+
+ if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0 ||
+ ((png_ptr->transformations & PNG_ADD_ALPHA) != 0 &&
+ (png_ptr->flags & PNG_FLAG_FILLER_AFTER) == 0))
+ {
+ if (do_local_background == 2)
+ png_error(png_ptr, "unexpected alpha swap transformation");
+
+ info_format |= PNG_FORMAT_FLAG_AFIRST;
+ }
+# endif
+
+ /* This is actually an internal error. */
+ if (info_format != format)
+ png_error(png_ptr, "png_read_image: invalid transformations");
+ }
+
+ /* Now read the rows. If do_local_compose is set then it is necessary to use
+ * a local row buffer. The output will be GA, RGBA or BGRA and must be
+ * converted to G, RGB or BGR as appropriate. The 'local_row' member of the
+ * display acts as a flag.
+ */
+ {
+ png_voidp first_row = display->buffer;
+ ptrdiff_t row_bytes = display->row_stride;
+
+ if (linear != 0)
+ row_bytes *= 2;
+
+ /* The following expression is designed to work correctly whether it gives
+ * a signed or an unsigned result.
+ */
+ if (row_bytes < 0)
+ {
+ char *ptr = png_voidcast(char*, first_row);
+ ptr += (image->height-1) * (-row_bytes);
+ first_row = png_voidcast(png_voidp, ptr);
+ }
+
+ display->first_row = first_row;
+ display->row_bytes = row_bytes;
+ }
+
+ if (do_local_compose != 0)
+ {
+ int result;
+ png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr));
+
+ display->local_row = row;
+ result = png_safe_execute(image, png_image_read_composite, display);
+ display->local_row = NULL;
+ png_free(png_ptr, row);
+
+ return result;
+ }
+
+ else if (do_local_background == 2)
+ {
+ int result;
+ png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr));
+
+ display->local_row = row;
+ result = png_safe_execute(image, png_image_read_background, display);
+ display->local_row = NULL;
+ png_free(png_ptr, row);
+
+ return result;
+ }
+
+ else
+ {
+ png_alloc_size_t row_bytes = (png_alloc_size_t)display->row_bytes;
+
+ while (--passes >= 0)
+ {
+ png_uint_32 y = image->height;
+ png_bytep row = png_voidcast(png_bytep, display->first_row);
+
+ for (; y > 0; --y)
+ {
+ png_read_row(png_ptr, row, NULL);
+ row += row_bytes;
+ }
+ }
+
+ return 1;
+ }
+}
+
+int PNGAPI
+png_image_finish_read(png_imagep image, png_const_colorp background,
+ void *buffer, png_int_32 row_stride, void *colormap)
+{
+ if (image != NULL && image->version == PNG_IMAGE_VERSION)
+ {
+ /* Check for row_stride overflow. This check is not performed on the
+ * original PNG format because it may not occur in the output PNG format
+ * and libpng deals with the issues of reading the original.
+ */
+ unsigned int channels = PNG_IMAGE_PIXEL_CHANNELS(image->format);
+
+ /* The following checks just the 'row_stride' calculation to ensure it
+ * fits in a signed 32-bit value. Because channels/components can be
+ * either 1 or 2 bytes in size the length of a row can still overflow 32
+ * bits; this is just to verify that the 'row_stride' argument can be
+ * represented.
+ */
+ if (image->width <= 0x7fffffffU/channels) /* no overflow */
+ {
+ png_uint_32 check;
+ png_uint_32 png_row_stride = image->width * channels;
+
+ if (row_stride == 0)
+ row_stride = (png_int_32)/*SAFE*/png_row_stride;
+
+ if (row_stride < 0)
+ check = (png_uint_32)(-row_stride);
+
+ else
+ check = (png_uint_32)row_stride;
+
+ /* This verifies 'check', the absolute value of the actual stride
+ * passed in and detects overflow in the application calculation (i.e.
+ * if the app did actually pass in a non-zero 'row_stride'.
+ */
+ if (image->opaque != NULL && buffer != NULL && check >= png_row_stride)
+ {
+ /* Now check for overflow of the image buffer calculation; this
+ * limits the whole image size to 32 bits for API compatibility with
+ * the current, 32-bit, PNG_IMAGE_BUFFER_SIZE macro.
+ *
+ * The PNG_IMAGE_BUFFER_SIZE macro is:
+ *
+ * (PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)*height*(row_stride))
+ *
+ * And the component size is always 1 or 2, so make sure that the
+ * number of *bytes* that the application is saying are available
+ * does actually fit into a 32-bit number.
+ *
+ * NOTE: this will be changed in 1.7 because PNG_IMAGE_BUFFER_SIZE
+ * will be changed to use png_alloc_size_t; bigger images can be
+ * accommodated on 64-bit systems.
+ */
+ if (image->height <=
+ 0xffffffffU/PNG_IMAGE_PIXEL_COMPONENT_SIZE(image->format)/check)
+ {
+ if ((image->format & PNG_FORMAT_FLAG_COLORMAP) == 0 ||
+ (image->colormap_entries > 0 && colormap != NULL))
+ {
+ int result;
+ png_image_read_control display;
+
+ memset(&display, 0, (sizeof display));
+ display.image = image;
+ display.buffer = buffer;
+ display.row_stride = row_stride;
+ display.colormap = colormap;
+ display.background = background;
+ display.local_row = NULL;
+
+ /* Choose the correct 'end' routine; for the color-map case
+ * all the setup has already been done.
+ */
+ if ((image->format & PNG_FORMAT_FLAG_COLORMAP) != 0)
+ result =
+ png_safe_execute(image,
+ png_image_read_colormap, &display) &&
+ png_safe_execute(image,
+ png_image_read_colormapped, &display);
+
+ else
+ result =
+ png_safe_execute(image,
+ png_image_read_direct, &display);
+
+ png_image_free(image);
+ return result;
+ }
+
+ else
+ return png_image_error(image,
+ "png_image_finish_read[color-map]: no color-map");
+ }
+
+ else
+ return png_image_error(image,
+ "png_image_finish_read: image too large");
+ }
+
+ else
+ return png_image_error(image,
+ "png_image_finish_read: invalid argument");
+ }
+
+ else
+ return png_image_error(image,
+ "png_image_finish_read: row_stride too large");
+ }
+
+ else if (image != NULL)
+ return png_image_error(image,
+ "png_image_finish_read: damaged PNG_IMAGE_VERSION");
+
+ return 0;
+}
+
+#endif /* SIMPLIFIED_READ */
+#endif /* READ */
diff --git a/libs/imagequant/external/libpng/pngrio.c b/libs/imagequant/external/libpng/pngrio.c
new file mode 100644
index 00000000..b4a21616
--- /dev/null
+++ b/libs/imagequant/external/libpng/pngrio.c
@@ -0,0 +1,119 @@
+/* pngrio.c - functions for data input
+ *
+ * Copyright (c) 2018-2025 Cosmin Truta
+ * Copyright (c) 1998-2002,2004,2006-2016,2018 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all input. Users who need
+ * special handling are expected to write a function that has the same
+ * arguments as this and performs a similar function, but that possibly
+ * has a different input method. Note that you shouldn't change this
+ * function, but rather write a replacement function and then make
+ * libpng use it at run time with png_set_read_fn(...).
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+/* Read the data from whatever input you are using. The default routine
+ * reads from a file pointer. Note that this routine sometimes gets called
+ * with very small lengths, so you should implement some kind of simple
+ * buffering if you are using unbuffered reads. This should never be asked
+ * to read more than 64K on a 16-bit machine.
+ */
+void /* PRIVATE */
+png_read_data(png_structrp png_ptr, png_bytep data, size_t length)
+{
+ png_debug1(4, "reading %d bytes", (int)length);
+
+ if (png_ptr->read_data_fn != NULL)
+ (*(png_ptr->read_data_fn))(png_ptr, data, length);
+
+ else
+ png_error(png_ptr, "Call to NULL read function");
+}
+
+#ifdef PNG_STDIO_SUPPORTED
+/* This is the function that does the actual reading of data. If you are
+ * not reading from a standard C stream, you should create a replacement
+ * read_data function and use it at run time with png_set_read_fn(), rather
+ * than changing the library.
+ */
+void PNGCBAPI
+png_default_read_data(png_structp png_ptr, png_bytep data, size_t length)
+{
+ size_t check;
+
+ if (png_ptr == NULL)
+ return;
+
+ /* fread() returns 0 on error, so it is OK to store this in a size_t
+ * instead of an int, which is what fread() actually returns.
+ */
+ check = fread(data, 1, length, png_voidcast(FILE *, png_ptr->io_ptr));
+
+ if (check != length)
+ png_error(png_ptr, "Read Error");
+}
+#endif
+
+/* This function allows the application to supply a new input function
+ * for libpng if standard C streams aren't being used.
+ *
+ * This function takes as its arguments:
+ *
+ * png_ptr - pointer to a png input data structure
+ *
+ * io_ptr - pointer to user supplied structure containing info about
+ * the input functions. May be NULL.
+ *
+ * read_data_fn - pointer to a new input function that takes as its
+ * arguments a pointer to a png_struct, a pointer to
+ * a location where input data can be stored, and a 32-bit
+ * unsigned int that is the number of bytes to be read.
+ * To exit and output any fatal error messages the new write
+ * function should call png_error(png_ptr, "Error msg").
+ * May be NULL, in which case libpng's default function will
+ * be used.
+ */
+void PNGAPI
+png_set_read_fn(png_structrp png_ptr, png_voidp io_ptr,
+ png_rw_ptr read_data_fn)
+{
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->io_ptr = io_ptr;
+
+#ifdef PNG_STDIO_SUPPORTED
+ if (read_data_fn != NULL)
+ png_ptr->read_data_fn = read_data_fn;
+
+ else
+ png_ptr->read_data_fn = png_default_read_data;
+#else
+ png_ptr->read_data_fn = read_data_fn;
+#endif
+
+#ifdef PNG_WRITE_SUPPORTED
+ /* It is an error to write to a read device */
+ if (png_ptr->write_data_fn != NULL)
+ {
+ png_ptr->write_data_fn = NULL;
+ png_warning(png_ptr,
+ "Can't set both read_data_fn and write_data_fn in the"
+ " same structure");
+ }
+#endif
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+ png_ptr->output_flush_fn = NULL;
+#endif
+}
+#endif /* READ */
diff --git a/libs/imagequant/external/libpng/pngrtran.c b/libs/imagequant/external/libpng/pngrtran.c
new file mode 100644
index 00000000..1809db70
--- /dev/null
+++ b/libs/imagequant/external/libpng/pngrtran.c
@@ -0,0 +1,5124 @@
+/* pngrtran.c - transforms the data in a row for PNG readers
+ *
+ * Copyright (c) 2018-2025 Cosmin Truta
+ * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file contains functions optionally called by an application
+ * in order to tell libpng how to handle data when reading a PNG.
+ * Transformations that are used in both reading and writing are
+ * in pngtrans.c.
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_ARM_NEON_IMPLEMENTATION
+# if PNG_ARM_NEON_IMPLEMENTATION == 1
+# define PNG_ARM_NEON_INTRINSICS_AVAILABLE
+# if defined(_MSC_VER) && !defined(__clang__) && defined(_M_ARM64)
+# include
+# else
+# include
+# endif
+# endif
+#endif
+
+#ifdef PNG_RISCV_RVV_IMPLEMENTATION
+# if PNG_RISCV_RVV_IMPLEMENTATION == 1
+# define PNG_RISCV_RVV_INTRINSICS_AVAILABLE
+# endif
+#endif
+
+#ifdef PNG_READ_SUPPORTED
+
+/* Set the action on getting a CRC error for an ancillary or critical chunk. */
+void PNGAPI
+png_set_crc_action(png_structrp png_ptr, int crit_action, int ancil_action)
+{
+ png_debug(1, "in png_set_crc_action");
+
+ if (png_ptr == NULL)
+ return;
+
+ /* Tell libpng how we react to CRC errors in critical chunks */
+ switch (crit_action)
+ {
+ case PNG_CRC_NO_CHANGE: /* Leave setting as is */
+ break;
+
+ case PNG_CRC_WARN_USE: /* Warn/use data */
+ png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
+ png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE;
+ break;
+
+ case PNG_CRC_QUIET_USE: /* Quiet/use data */
+ png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
+ png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE |
+ PNG_FLAG_CRC_CRITICAL_IGNORE;
+ break;
+
+ case PNG_CRC_WARN_DISCARD: /* Not a valid action for critical data */
+ png_warning(png_ptr,
+ "Can't discard critical data on CRC error");
+ /* FALLTHROUGH */
+ case PNG_CRC_ERROR_QUIT: /* Error/quit */
+
+ case PNG_CRC_DEFAULT:
+ default:
+ png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
+ break;
+ }
+
+ /* Tell libpng how we react to CRC errors in ancillary chunks */
+ switch (ancil_action)
+ {
+ case PNG_CRC_NO_CHANGE: /* Leave setting as is */
+ break;
+
+ case PNG_CRC_WARN_USE: /* Warn/use data */
+ png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+ png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE;
+ break;
+
+ case PNG_CRC_QUIET_USE: /* Quiet/use data */
+ png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+ png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE |
+ PNG_FLAG_CRC_ANCILLARY_NOWARN;
+ break;
+
+ case PNG_CRC_ERROR_QUIT: /* Error/quit */
+ png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+ png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN;
+ break;
+
+ case PNG_CRC_WARN_DISCARD: /* Warn/discard data */
+
+ case PNG_CRC_DEFAULT:
+ default:
+ png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+ break;
+ }
+}
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+/* Is it OK to set a transformation now? Only if png_start_read_image or
+ * png_read_update_info have not been called. It is not necessary for the IHDR
+ * to have been read in all cases; the need_IHDR parameter allows for this
+ * check too.
+ */
+static int
+png_rtran_ok(png_structrp png_ptr, int need_IHDR)
+{
+ if (png_ptr != NULL)
+ {
+ if ((png_ptr->flags & PNG_FLAG_ROW_INIT) != 0)
+ png_app_error(png_ptr,
+ "invalid after png_start_read_image or png_read_update_info");
+
+ else if (need_IHDR && (png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_app_error(png_ptr, "invalid before the PNG header has been read");
+
+ else
+ {
+ /* Turn on failure to initialize correctly for all transforms. */
+ png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED;
+
+ return 1; /* Ok */
+ }
+ }
+
+ return 0; /* no png_error possible! */
+}
+#endif
+
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+/* Handle alpha and tRNS via a background color */
+void PNGFAPI
+png_set_background_fixed(png_structrp png_ptr,
+ png_const_color_16p background_color, int background_gamma_code,
+ int need_expand, png_fixed_point background_gamma)
+{
+ png_debug(1, "in png_set_background_fixed");
+
+ if (png_rtran_ok(png_ptr, 0) == 0 || background_color == NULL)
+ return;
+
+ if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN)
+ {
+ png_warning(png_ptr, "Application must supply a known background gamma");
+ return;
+ }
+
+ png_ptr->transformations |= PNG_COMPOSE | PNG_STRIP_ALPHA;
+ png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+ png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+
+ png_ptr->background = *background_color;
+ png_ptr->background_gamma = background_gamma;
+ png_ptr->background_gamma_type = (png_byte)(background_gamma_code);
+ if (need_expand != 0)
+ png_ptr->transformations |= PNG_BACKGROUND_EXPAND;
+ else
+ png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND;
+}
+
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_background(png_structrp png_ptr,
+ png_const_color_16p background_color, int background_gamma_code,
+ int need_expand, double background_gamma)
+{
+ png_set_background_fixed(png_ptr, background_color, background_gamma_code,
+ need_expand, png_fixed(png_ptr, background_gamma, "png_set_background"));
+}
+# endif /* FLOATING_POINT */
+#endif /* READ_BACKGROUND */
+
+/* Scale 16-bit depth files to 8-bit depth. If both of these are set then the
+ * one that pngrtran does first (scale) happens. This is necessary to allow the
+ * TRANSFORM and API behavior to be somewhat consistent, and it's simpler.
+ */
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+void PNGAPI
+png_set_scale_16(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_scale_16");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ png_ptr->transformations |= PNG_SCALE_16_TO_8;
+}
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+/* Chop 16-bit depth files to 8-bit depth */
+void PNGAPI
+png_set_strip_16(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_strip_16");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ png_ptr->transformations |= PNG_16_TO_8;
+}
+#endif
+
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+void PNGAPI
+png_set_strip_alpha(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_strip_alpha");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ png_ptr->transformations |= PNG_STRIP_ALPHA;
+}
+#endif
+
+#if defined(PNG_READ_ALPHA_MODE_SUPPORTED) || defined(PNG_READ_GAMMA_SUPPORTED)
+/* PNGv3 conformance: this private API exists to resolve the now mandatory error
+ * resolution when multiple conflicting sources of gamma or colour space
+ * information are available.
+ *
+ * Terminology (assuming power law, "gamma", encodings):
+ * "screen" gamma: a power law imposed by the output device when digital
+ * samples are converted to visible light output. The EOTF - volage to
+ * luminance on output.
+ *
+ * "file" gamma: a power law used to encode luminance levels from the input
+ * data (the scene or the mastering display system) into digital voltages.
+ * The OETF - luminance to voltage on input.
+ *
+ * gamma "correction": a power law matching the **inverse** of the overall
+ * transfer function from input luminance levels to output levels. The
+ * **inverse** of the OOTF; the correction "corrects" for the OOTF by aiming
+ * to make the overall OOTF (including the correction) linear.
+ *
+ * It is important to understand this terminology because the defined terms are
+ * scattered throughout the libpng code and it is very easy to end up with the
+ * inverse of the power law required.
+ *
+ * Variable and struct::member names:
+ * file_gamma OETF how the PNG data was encoded
+ *
+ * screen_gamma EOTF how the screen will decode digital levels
+ *
+ * -- not used -- OOTF the net effect OETF x EOTF
+ * gamma_correction the inverse of OOTF to make the result linear
+ *
+ * All versions of libpng require a call to "png_set_gamma" to establish the
+ * "screen" gamma, the power law representing the EOTF. png_set_gamma may also
+ * set or default the "file" gamma; the OETF. gamma_correction is calculated
+ * internally.
+ *
+ * The earliest libpng versions required file_gamma to be supplied to set_gamma.
+ * Later versions started allowing png_set_gamma and, later, png_set_alpha_mode,
+ * to cause defaulting from the file data.
+ *
+ * PNGv3 mandated a particular form for this defaulting, one that is compatible
+ * with what libpng did except that if libpng detected inconsistencies it marked
+ * all the chunks as "invalid". PNGv3 effectively invalidates this prior code.
+ *
+ * Behaviour implemented below:
+ * translate_gamma_flags(gamma, is_screen)
+ * The libpng-1.6 API for the gamma parameters to libpng APIs
+ * (png_set_gamma and png_set_alpha_mode at present). This allows the
+ * 'gamma' value to be passed as a png_fixed_point number or as one of a
+ * set of integral values for specific "well known" examples of transfer
+ * functions. This is compatible with PNGv3.
+ */
+static png_fixed_point
+translate_gamma_flags(png_fixed_point output_gamma, int is_screen)
+{
+ /* Check for flag values. The main reason for having the old Mac value as a
+ * flag is that it is pretty near impossible to work out what the correct
+ * value is from Apple documentation - a working Mac system is needed to
+ * discover the value!
+ */
+ if (output_gamma == PNG_DEFAULT_sRGB ||
+ output_gamma == PNG_FP_1 / PNG_DEFAULT_sRGB)
+ {
+ if (is_screen != 0)
+ output_gamma = PNG_GAMMA_sRGB;
+ else
+ output_gamma = PNG_GAMMA_sRGB_INVERSE;
+ }
+
+ else if (output_gamma == PNG_GAMMA_MAC_18 ||
+ output_gamma == PNG_FP_1 / PNG_GAMMA_MAC_18)
+ {
+ if (is_screen != 0)
+ output_gamma = PNG_GAMMA_MAC_OLD;
+ else
+ output_gamma = PNG_GAMMA_MAC_INVERSE;
+ }
+
+ return output_gamma;
+}
+
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+static png_fixed_point
+convert_gamma_value(png_structrp png_ptr, double output_gamma)
+{
+ /* The following silently ignores cases where fixed point (times 100,000)
+ * gamma values are passed to the floating point API. This is safe and it
+ * means the fixed point constants work just fine with the floating point
+ * API. The alternative would just lead to undetected errors and spurious
+ * bug reports. Negative values fail inside the _fixed API unless they
+ * correspond to the flag values.
+ */
+ if (output_gamma > 0 && output_gamma < 128)
+ output_gamma *= PNG_FP_1;
+
+ /* This preserves -1 and -2 exactly: */
+ output_gamma = floor(output_gamma + .5);
+
+ if (output_gamma > PNG_FP_MAX || output_gamma < PNG_FP_MIN)
+ png_fixed_error(png_ptr, "gamma value");
+
+ return (png_fixed_point)output_gamma;
+}
+# endif
+
+static int
+unsupported_gamma(png_structrp png_ptr, png_fixed_point gamma, int warn)
+{
+ /* Validate a gamma value to ensure it is in a reasonable range. The value
+ * is expected to be 1 or greater, but this range test allows for some
+ * viewing correction values. The intent is to weed out the API users
+ * who might use the inverse of the gamma value accidentally!
+ *
+ * 1.6.47: apply the test in png_set_gamma as well but only warn and return
+ * false if it fires.
+ *
+ * TODO: 1.8: make this an app_error in png_set_gamma as well.
+ */
+ if (gamma < PNG_LIB_GAMMA_MIN || gamma > PNG_LIB_GAMMA_MAX)
+ {
+# define msg "gamma out of supported range"
+ if (warn)
+ png_app_warning(png_ptr, msg);
+ else
+ png_app_error(png_ptr, msg);
+ return 1;
+# undef msg
+ }
+
+ return 0;
+}
+#endif /* READ_ALPHA_MODE || READ_GAMMA */
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+void PNGFAPI
+png_set_alpha_mode_fixed(png_structrp png_ptr, int mode,
+ png_fixed_point output_gamma)
+{
+ png_fixed_point file_gamma;
+ int compose = 0;
+
+ png_debug(1, "in png_set_alpha_mode_fixed");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ output_gamma = translate_gamma_flags(output_gamma, 1/*screen*/);
+ if (unsupported_gamma(png_ptr, output_gamma, 0/*error*/))
+ return;
+
+ /* The default file gamma is the inverse of the output gamma; the output
+ * gamma may be changed below so get the file value first. The default_gamma
+ * is set here and from the simplified API (which uses a different algorithm)
+ * so don't overwrite a set value:
+ */
+ file_gamma = png_ptr->default_gamma;
+ if (file_gamma == 0)
+ {
+ file_gamma = png_reciprocal(output_gamma);
+ png_ptr->default_gamma = file_gamma;
+ }
+
+ /* There are really 8 possibilities here, composed of any combination
+ * of:
+ *
+ * premultiply the color channels
+ * do not encode non-opaque pixels
+ * encode the alpha as well as the color channels
+ *
+ * The differences disappear if the input/output ('screen') gamma is 1.0,
+ * because then the encoding is a no-op and there is only the choice of
+ * premultiplying the color channels or not.
+ *
+ * png_set_alpha_mode and png_set_background interact because both use
+ * png_compose to do the work. Calling both is only useful when
+ * png_set_alpha_mode is used to set the default mode - PNG_ALPHA_PNG - along
+ * with a default gamma value. Otherwise PNG_COMPOSE must not be set.
+ */
+ switch (mode)
+ {
+ case PNG_ALPHA_PNG: /* default: png standard */
+ /* No compose, but it may be set by png_set_background! */
+ png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+ png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+ break;
+
+ case PNG_ALPHA_ASSOCIATED: /* color channels premultiplied */
+ compose = 1;
+ png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+ png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+ /* The output is linear: */
+ output_gamma = PNG_FP_1;
+ break;
+
+ case PNG_ALPHA_OPTIMIZED: /* associated, non-opaque pixels linear */
+ compose = 1;
+ png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+ png_ptr->flags |= PNG_FLAG_OPTIMIZE_ALPHA;
+ /* output_gamma records the encoding of opaque pixels! */
+ break;
+
+ case PNG_ALPHA_BROKEN: /* associated, non-linear, alpha encoded */
+ compose = 1;
+ png_ptr->transformations |= PNG_ENCODE_ALPHA;
+ png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+ break;
+
+ default:
+ png_error(png_ptr, "invalid alpha mode");
+ }
+
+ /* Set the screen gamma values: */
+ png_ptr->screen_gamma = output_gamma;
+
+ /* Finally, if pre-multiplying, set the background fields to achieve the
+ * desired result.
+ */
+ if (compose != 0)
+ {
+ /* And obtain alpha pre-multiplication by composing on black: */
+ memset(&png_ptr->background, 0, (sizeof png_ptr->background));
+ png_ptr->background_gamma = file_gamma; /* just in case */
+ png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_FILE;
+ png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND;
+
+ if ((png_ptr->transformations & PNG_COMPOSE) != 0)
+ png_error(png_ptr,
+ "conflicting calls to set alpha mode and background");
+
+ png_ptr->transformations |= PNG_COMPOSE;
+ }
+}
+
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_alpha_mode(png_structrp png_ptr, int mode, double output_gamma)
+{
+ png_set_alpha_mode_fixed(png_ptr, mode, convert_gamma_value(png_ptr,
+ output_gamma));
+}
+# endif
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+/* Dither file to 8-bit. Supply a palette, the current number
+ * of elements in the palette, the maximum number of elements
+ * allowed, and a histogram if possible. If the current number
+ * of colors is greater than the maximum number, the palette will be
+ * modified to fit in the maximum number. "full_quantize" indicates
+ * whether we need a quantizing cube set up for RGB images, or if we
+ * simply are reducing the number of colors in a paletted image.
+ */
+
+typedef struct png_dsort_struct
+{
+ struct png_dsort_struct * next;
+ png_byte left;
+ png_byte right;
+} png_dsort;
+typedef png_dsort * png_dsortp;
+typedef png_dsort * * png_dsortpp;
+
+void PNGAPI
+png_set_quantize(png_structrp png_ptr, png_colorp palette,
+ int num_palette, int maximum_colors, png_const_uint_16p histogram,
+ int full_quantize)
+{
+ png_debug(1, "in png_set_quantize");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ png_ptr->transformations |= PNG_QUANTIZE;
+
+ if (full_quantize == 0)
+ {
+ int i;
+
+ png_ptr->quantize_index = (png_bytep)png_malloc(png_ptr,
+ (png_alloc_size_t)num_palette);
+ for (i = 0; i < num_palette; i++)
+ png_ptr->quantize_index[i] = (png_byte)i;
+ }
+
+ if (num_palette > maximum_colors)
+ {
+ if (histogram != NULL)
+ {
+ /* This is easy enough, just throw out the least used colors.
+ * Perhaps not the best solution, but good enough.
+ */
+
+ int i;
+
+ /* Initialize an array to sort colors */
+ png_ptr->quantize_sort = (png_bytep)png_malloc(png_ptr,
+ (png_alloc_size_t)num_palette);
+
+ /* Initialize the quantize_sort array */
+ for (i = 0; i < num_palette; i++)
+ png_ptr->quantize_sort[i] = (png_byte)i;
+
+ /* Find the least used palette entries by starting a
+ * bubble sort, and running it until we have sorted
+ * out enough colors. Note that we don't care about
+ * sorting all the colors, just finding which are
+ * least used.
+ */
+
+ for (i = num_palette - 1; i >= maximum_colors; i--)
+ {
+ int done; /* To stop early if the list is pre-sorted */
+ int j;
+
+ done = 1;
+ for (j = 0; j < i; j++)
+ {
+ if (histogram[png_ptr->quantize_sort[j]]
+ < histogram[png_ptr->quantize_sort[j + 1]])
+ {
+ png_byte t;
+
+ t = png_ptr->quantize_sort[j];
+ png_ptr->quantize_sort[j] = png_ptr->quantize_sort[j + 1];
+ png_ptr->quantize_sort[j + 1] = t;
+ done = 0;
+ }
+ }
+
+ if (done != 0)
+ break;
+ }
+
+ /* Swap the palette around, and set up a table, if necessary */
+ if (full_quantize != 0)
+ {
+ int j = num_palette;
+
+ /* Put all the useful colors within the max, but don't
+ * move the others.
+ */
+ for (i = 0; i < maximum_colors; i++)
+ {
+ if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
+ {
+ do
+ j--;
+ while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
+
+ palette[i] = palette[j];
+ }
+ }
+ }
+ else
+ {
+ int j = num_palette;
+
+ /* Move all the used colors inside the max limit, and
+ * develop a translation table.
+ */
+ for (i = 0; i < maximum_colors; i++)
+ {
+ /* Only move the colors we need to */
+ if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
+ {
+ png_color tmp_color;
+
+ do
+ j--;
+ while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
+
+ tmp_color = palette[j];
+ palette[j] = palette[i];
+ palette[i] = tmp_color;
+ /* Indicate where the color went */
+ png_ptr->quantize_index[j] = (png_byte)i;
+ png_ptr->quantize_index[i] = (png_byte)j;
+ }
+ }
+
+ /* Find closest color for those colors we are not using */
+ for (i = 0; i < num_palette; i++)
+ {
+ if ((int)png_ptr->quantize_index[i] >= maximum_colors)
+ {
+ int min_d, k, min_k, d_index;
+
+ /* Find the closest color to one we threw out */
+ d_index = png_ptr->quantize_index[i];
+ min_d = PNG_COLOR_DIST(palette[d_index], palette[0]);
+ for (k = 1, min_k = 0; k < maximum_colors; k++)
+ {
+ int d;
+
+ d = PNG_COLOR_DIST(palette[d_index], palette[k]);
+
+ if (d < min_d)
+ {
+ min_d = d;
+ min_k = k;
+ }
+ }
+ /* Point to closest color */
+ png_ptr->quantize_index[i] = (png_byte)min_k;
+ }
+ }
+ }
+ png_free(png_ptr, png_ptr->quantize_sort);
+ png_ptr->quantize_sort = NULL;
+ }
+ else
+ {
+ /* This is much harder to do simply (and quickly). Perhaps
+ * we need to go through a median cut routine, but those
+ * don't always behave themselves with only a few colors
+ * as input. So we will just find the closest two colors,
+ * and throw out one of them (chosen somewhat randomly).
+ * [We don't understand this at all, so if someone wants to
+ * work on improving it, be our guest - AED, GRP]
+ */
+ int i;
+ int max_d;
+ int num_new_palette;
+ png_dsortp t;
+ png_dsortpp hash;
+
+ t = NULL;
+
+ /* Initialize palette index arrays */
+ png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr,
+ (png_alloc_size_t)num_palette);
+ png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr,
+ (png_alloc_size_t)num_palette);
+
+ /* Initialize the sort array */
+ for (i = 0; i < num_palette; i++)
+ {
+ png_ptr->index_to_palette[i] = (png_byte)i;
+ png_ptr->palette_to_index[i] = (png_byte)i;
+ }
+
+ hash = (png_dsortpp)png_calloc(png_ptr, (png_alloc_size_t)(769 *
+ (sizeof (png_dsortp))));
+
+ num_new_palette = num_palette;
+
+ /* Initial wild guess at how far apart the farthest pixel
+ * pair we will be eliminating will be. Larger
+ * numbers mean more areas will be allocated, Smaller
+ * numbers run the risk of not saving enough data, and
+ * having to do this all over again.
+ *
+ * I have not done extensive checking on this number.
+ */
+ max_d = 96;
+
+ while (num_new_palette > maximum_colors)
+ {
+ for (i = 0; i < num_new_palette - 1; i++)
+ {
+ int j;
+
+ for (j = i + 1; j < num_new_palette; j++)
+ {
+ int d;
+
+ d = PNG_COLOR_DIST(palette[i], palette[j]);
+
+ if (d <= max_d)
+ {
+
+ t = (png_dsortp)png_malloc_warn(png_ptr,
+ (png_alloc_size_t)(sizeof (png_dsort)));
+
+ if (t == NULL)
+ break;
+
+ t->next = hash[d];
+ t->left = (png_byte)i;
+ t->right = (png_byte)j;
+ hash[d] = t;
+ }
+ }
+ if (t == NULL)
+ break;
+ }
+
+ if (t != NULL)
+ for (i = 0; i <= max_d; i++)
+ {
+ if (hash[i] != NULL)
+ {
+ png_dsortp p;
+
+ for (p = hash[i]; p; p = p->next)
+ {
+ if ((int)png_ptr->index_to_palette[p->left]
+ < num_new_palette &&
+ (int)png_ptr->index_to_palette[p->right]
+ < num_new_palette)
+ {
+ int j, next_j;
+
+ if (num_new_palette & 0x01)
+ {
+ j = p->left;
+ next_j = p->right;
+ }
+ else
+ {
+ j = p->right;
+ next_j = p->left;
+ }
+
+ num_new_palette--;
+ palette[png_ptr->index_to_palette[j]]
+ = palette[num_new_palette];
+ if (full_quantize == 0)
+ {
+ int k;
+
+ for (k = 0; k < num_palette; k++)
+ {
+ if (png_ptr->quantize_index[k] ==
+ png_ptr->index_to_palette[j])
+ png_ptr->quantize_index[k] =
+ png_ptr->index_to_palette[next_j];
+
+ if ((int)png_ptr->quantize_index[k] ==
+ num_new_palette)
+ png_ptr->quantize_index[k] =
+ png_ptr->index_to_palette[j];
+ }
+ }
+
+ png_ptr->index_to_palette[png_ptr->palette_to_index
+ [num_new_palette]] = png_ptr->index_to_palette[j];
+
+ png_ptr->palette_to_index[png_ptr->index_to_palette[j]]
+ = png_ptr->palette_to_index[num_new_palette];
+
+ png_ptr->index_to_palette[j] =
+ (png_byte)num_new_palette;
+
+ png_ptr->palette_to_index[num_new_palette] =
+ (png_byte)j;
+ }
+ if (num_new_palette <= maximum_colors)
+ break;
+ }
+ if (num_new_palette <= maximum_colors)
+ break;
+ }
+ }
+
+ for (i = 0; i < 769; i++)
+ {
+ if (hash[i] != NULL)
+ {
+ png_dsortp p = hash[i];
+ while (p)
+ {
+ t = p->next;
+ png_free(png_ptr, p);
+ p = t;
+ }
+ }
+ hash[i] = 0;
+ }
+ max_d += 96;
+ }
+ png_free(png_ptr, hash);
+ png_free(png_ptr, png_ptr->palette_to_index);
+ png_free(png_ptr, png_ptr->index_to_palette);
+ png_ptr->palette_to_index = NULL;
+ png_ptr->index_to_palette = NULL;
+ }
+ num_palette = maximum_colors;
+ }
+ if (png_ptr->palette == NULL)
+ {
+ png_ptr->palette = palette;
+ }
+ png_ptr->num_palette = (png_uint_16)num_palette;
+
+ if (full_quantize != 0)
+ {
+ int i;
+ png_bytep distance;
+ int total_bits = PNG_QUANTIZE_RED_BITS + PNG_QUANTIZE_GREEN_BITS +
+ PNG_QUANTIZE_BLUE_BITS;
+ int num_red = (1 << PNG_QUANTIZE_RED_BITS);
+ int num_green = (1 << PNG_QUANTIZE_GREEN_BITS);
+ int num_blue = (1 << PNG_QUANTIZE_BLUE_BITS);
+ size_t num_entries = ((size_t)1 << total_bits);
+
+ png_ptr->palette_lookup = (png_bytep)png_calloc(png_ptr,
+ (png_alloc_size_t)(num_entries));
+
+ distance = (png_bytep)png_malloc(png_ptr, (png_alloc_size_t)num_entries);
+
+ memset(distance, 0xff, num_entries);
+
+ for (i = 0; i < num_palette; i++)
+ {
+ int ir, ig, ib;
+ int r = (palette[i].red >> (8 - PNG_QUANTIZE_RED_BITS));
+ int g = (palette[i].green >> (8 - PNG_QUANTIZE_GREEN_BITS));
+ int b = (palette[i].blue >> (8 - PNG_QUANTIZE_BLUE_BITS));
+
+ for (ir = 0; ir < num_red; ir++)
+ {
+ /* int dr = abs(ir - r); */
+ int dr = ((ir > r) ? ir - r : r - ir);
+ int index_r = (ir << (PNG_QUANTIZE_BLUE_BITS +
+ PNG_QUANTIZE_GREEN_BITS));
+
+ for (ig = 0; ig < num_green; ig++)
+ {
+ /* int dg = abs(ig - g); */
+ int dg = ((ig > g) ? ig - g : g - ig);
+ int dt = dr + dg;
+ int dm = ((dr > dg) ? dr : dg);
+ int index_g = index_r | (ig << PNG_QUANTIZE_BLUE_BITS);
+
+ for (ib = 0; ib < num_blue; ib++)
+ {
+ int d_index = index_g | ib;
+ /* int db = abs(ib - b); */
+ int db = ((ib > b) ? ib - b : b - ib);
+ int dmax = ((dm > db) ? dm : db);
+ int d = dmax + dt + db;
+
+ if (d < (int)distance[d_index])
+ {
+ distance[d_index] = (png_byte)d;
+ png_ptr->palette_lookup[d_index] = (png_byte)i;
+ }
+ }
+ }
+ }
+ }
+
+ png_free(png_ptr, distance);
+ }
+}
+#endif /* READ_QUANTIZE */
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+void PNGFAPI
+png_set_gamma_fixed(png_structrp png_ptr, png_fixed_point scrn_gamma,
+ png_fixed_point file_gamma)
+{
+ png_debug(1, "in png_set_gamma_fixed");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ /* New in libpng-1.5.4 - reserve particular negative values as flags. */
+ scrn_gamma = translate_gamma_flags(scrn_gamma, 1/*screen*/);
+ file_gamma = translate_gamma_flags(file_gamma, 0/*file*/);
+
+ /* Checking the gamma values for being >0 was added in 1.5.4 along with the
+ * premultiplied alpha support; this actually hides an undocumented feature
+ * of the previous implementation which allowed gamma processing to be
+ * disabled in background handling. There is no evidence (so far) that this
+ * was being used; however, png_set_background itself accepted and must still
+ * accept '0' for the gamma value it takes, because it isn't always used.
+ *
+ * Since this is an API change (albeit a very minor one that removes an
+ * undocumented API feature) the following checks were only enabled in
+ * libpng-1.6.0.
+ */
+ if (file_gamma <= 0)
+ png_app_error(png_ptr, "invalid file gamma in png_set_gamma");
+ if (scrn_gamma <= 0)
+ png_app_error(png_ptr, "invalid screen gamma in png_set_gamma");
+
+ if (unsupported_gamma(png_ptr, file_gamma, 1/*warn*/) ||
+ unsupported_gamma(png_ptr, scrn_gamma, 1/*warn*/))
+ return;
+
+ /* 1.6.47: png_struct::file_gamma and png_struct::screen_gamma are now only
+ * written by this API. This removes dependencies on the order of API calls
+ * and allows the complex gamma checks to be delayed until needed.
+ */
+ png_ptr->file_gamma = file_gamma;
+ png_ptr->screen_gamma = scrn_gamma;
+}
+
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_gamma(png_structrp png_ptr, double scrn_gamma, double file_gamma)
+{
+ png_set_gamma_fixed(png_ptr, convert_gamma_value(png_ptr, scrn_gamma),
+ convert_gamma_value(png_ptr, file_gamma));
+}
+# endif /* FLOATING_POINT */
+#endif /* READ_GAMMA */
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+/* Expand paletted images to RGB, expand grayscale images of
+ * less than 8-bit depth to 8-bit depth, and expand tRNS chunks
+ * to alpha channels.
+ */
+void PNGAPI
+png_set_expand(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_expand");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
+}
+
+/* GRR 19990627: the following three functions currently are identical
+ * to png_set_expand(). However, it is entirely reasonable that someone
+ * might wish to expand an indexed image to RGB but *not* expand a single,
+ * fully transparent palette entry to a full alpha channel--perhaps instead
+ * convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace
+ * the transparent color with a particular RGB value, or drop tRNS entirely.
+ * IOW, a future version of the library may make the transformations flag
+ * a bit more fine-grained, with separate bits for each of these three
+ * functions.
+ *
+ * More to the point, these functions make it obvious what libpng will be
+ * doing, whereas "expand" can (and does) mean any number of things.
+ *
+ * GRP 20060307: In libpng-1.2.9, png_set_gray_1_2_4_to_8() was modified
+ * to expand only the sample depth but not to expand the tRNS to alpha
+ * and its name was changed to png_set_expand_gray_1_2_4_to_8().
+ */
+
+/* Expand paletted images to RGB. */
+void PNGAPI
+png_set_palette_to_rgb(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_palette_to_rgb");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
+}
+
+/* Expand grayscale images of less than 8-bit depth to 8 bits. */
+void PNGAPI
+png_set_expand_gray_1_2_4_to_8(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_expand_gray_1_2_4_to_8");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ png_ptr->transformations |= PNG_EXPAND;
+}
+
+/* Expand tRNS chunks to alpha channels. */
+void PNGAPI
+png_set_tRNS_to_alpha(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_tRNS_to_alpha");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
+}
+#endif /* READ_EXPAND */
+
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+/* Expand to 16-bit channels, expand the tRNS chunk too (because otherwise
+ * it may not work correctly.)
+ */
+void PNGAPI
+png_set_expand_16(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_expand_16");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ png_ptr->transformations |= (PNG_EXPAND_16 | PNG_EXPAND | PNG_EXPAND_tRNS);
+}
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+void PNGAPI
+png_set_gray_to_rgb(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_gray_to_rgb");
+
+ if (png_rtran_ok(png_ptr, 0) == 0)
+ return;
+
+ /* Because rgb must be 8 bits or more: */
+ png_set_expand_gray_1_2_4_to_8(png_ptr);
+ png_ptr->transformations |= PNG_GRAY_TO_RGB;
+}
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+void PNGFAPI
+png_set_rgb_to_gray_fixed(png_structrp png_ptr, int error_action,
+ png_fixed_point red, png_fixed_point green)
+{
+ png_debug(1, "in png_set_rgb_to_gray_fixed");
+
+ /* Need the IHDR here because of the check on color_type below. */
+ /* TODO: fix this */
+ if (png_rtran_ok(png_ptr, 1) == 0)
+ return;
+
+ switch (error_action)
+ {
+ case PNG_ERROR_ACTION_NONE:
+ png_ptr->transformations |= PNG_RGB_TO_GRAY;
+ break;
+
+ case PNG_ERROR_ACTION_WARN:
+ png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN;
+ break;
+
+ case PNG_ERROR_ACTION_ERROR:
+ png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR;
+ break;
+
+ default:
+ png_error(png_ptr, "invalid error action to rgb_to_gray");
+ }
+
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ png_ptr->transformations |= PNG_EXPAND;
+#else
+ {
+ /* Make this an error in 1.6 because otherwise the application may assume
+ * that it just worked and get a memory overwrite.
+ */
+ png_error(png_ptr,
+ "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED");
+
+ /* png_ptr->transformations &= ~PNG_RGB_TO_GRAY; */
+ }
+#endif
+ {
+ if (red >= 0 && green >= 0 && red + green <= PNG_FP_1)
+ {
+ png_uint_16 red_int, green_int;
+
+ /* NOTE: this calculation does not round, but this behavior is retained
+ * for consistency; the inaccuracy is very small. The code here always
+ * overwrites the coefficients, regardless of whether they have been
+ * defaulted or set already.
+ */
+ red_int = (png_uint_16)(((png_uint_32)red*32768)/100000);
+ green_int = (png_uint_16)(((png_uint_32)green*32768)/100000);
+
+ png_ptr->rgb_to_gray_red_coeff = red_int;
+ png_ptr->rgb_to_gray_green_coeff = green_int;
+ png_ptr->rgb_to_gray_coefficients_set = 1;
+ }
+
+ else if (red >= 0 && green >= 0)
+ png_app_warning(png_ptr,
+ "ignoring out of range rgb_to_gray coefficients");
+ }
+}
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+/* Convert a RGB image to a grayscale of the same width. This allows us,
+ * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image.
+ */
+
+void PNGAPI
+png_set_rgb_to_gray(png_structrp png_ptr, int error_action, double red,
+ double green)
+{
+ png_set_rgb_to_gray_fixed(png_ptr, error_action,
+ png_fixed(png_ptr, red, "rgb to gray red coefficient"),
+ png_fixed(png_ptr, green, "rgb to gray green coefficient"));
+}
+#endif /* FLOATING POINT */
+
+#endif /* RGB_TO_GRAY */
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+void PNGAPI
+png_set_read_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr
+ read_user_transform_fn)
+{
+ png_debug(1, "in png_set_read_user_transform_fn");
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+ png_ptr->transformations |= PNG_USER_TRANSFORM;
+ png_ptr->read_user_transform_fn = read_user_transform_fn;
+#endif
+}
+#endif
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* In the case of gamma transformations only do transformations on images where
+ * the [file] gamma and screen_gamma are not close reciprocals, otherwise it
+ * slows things down slightly, and also needlessly introduces small errors.
+ */
+static int /* PRIVATE */
+png_gamma_threshold(png_fixed_point screen_gamma, png_fixed_point file_gamma)
+{
+ /* PNG_GAMMA_THRESHOLD is the threshold for performing gamma
+ * correction as a difference of the overall transform from 1.0
+ *
+ * We want to compare the threshold with s*f - 1, if we get
+ * overflow here it is because of wacky gamma values so we
+ * turn on processing anyway.
+ */
+ png_fixed_point gtest;
+ return !png_muldiv(>est, screen_gamma, file_gamma, PNG_FP_1) ||
+ png_gamma_significant(gtest);
+}
+#endif
+
+/* Initialize everything needed for the read. This includes modifying
+ * the palette.
+ */
+
+/* For the moment 'png_init_palette_transformations' and
+ * 'png_init_rgb_transformations' only do some flag canceling optimizations.
+ * The intent is that these two routines should have palette or rgb operations
+ * extracted from 'png_init_read_transformations'.
+ */
+static void /* PRIVATE */
+png_init_palette_transformations(png_structrp png_ptr)
+{
+ /* Called to handle the (input) palette case. In png_do_read_transformations
+ * the first step is to expand the palette if requested, so this code must
+ * take care to only make changes that are invariant with respect to the
+ * palette expansion, or only do them if there is no expansion.
+ *
+ * STRIP_ALPHA has already been handled in the caller (by setting num_trans
+ * to 0.)
+ */
+ int input_has_alpha = 0;
+ int input_has_transparency = 0;
+
+ if (png_ptr->num_trans > 0)
+ {
+ int i;
+
+ /* Ignore if all the entries are opaque (unlikely!) */
+ for (i=0; inum_trans; ++i)
+ {
+ if (png_ptr->trans_alpha[i] == 255)
+ continue;
+ else if (png_ptr->trans_alpha[i] == 0)
+ input_has_transparency = 1;
+ else
+ {
+ input_has_transparency = 1;
+ input_has_alpha = 1;
+ break;
+ }
+ }
+ }
+
+ /* If no alpha we can optimize. */
+ if (input_has_alpha == 0)
+ {
+ /* Any alpha means background and associative alpha processing is
+ * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA
+ * and ENCODE_ALPHA are irrelevant.
+ */
+ png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+ png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+
+ if (input_has_transparency == 0)
+ png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND);
+ }
+
+#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
+ /* png_set_background handling - deals with the complexity of whether the
+ * background color is in the file format or the screen format in the case
+ * where an 'expand' will happen.
+ */
+
+ /* The following code cannot be entered in the alpha pre-multiplication case
+ * because PNG_BACKGROUND_EXPAND is cancelled below.
+ */
+ if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0 &&
+ (png_ptr->transformations & PNG_EXPAND) != 0)
+ {
+ {
+ png_ptr->background.red =
+ png_ptr->palette[png_ptr->background.index].red;
+ png_ptr->background.green =
+ png_ptr->palette[png_ptr->background.index].green;
+ png_ptr->background.blue =
+ png_ptr->palette[png_ptr->background.index].blue;
+
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+ if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0)
+ {
+ if ((png_ptr->transformations & PNG_EXPAND_tRNS) == 0)
+ {
+ /* Invert the alpha channel (in tRNS) unless the pixels are
+ * going to be expanded, in which case leave it for later
+ */
+ int i, istop = png_ptr->num_trans;
+
+ for (i = 0; i < istop; i++)
+ png_ptr->trans_alpha[i] =
+ (png_byte)(255 - png_ptr->trans_alpha[i]);
+ }
+ }
+#endif /* READ_INVERT_ALPHA */
+ }
+ } /* background expand and (therefore) no alpha association. */
+#endif /* READ_EXPAND && READ_BACKGROUND */
+}
+
+static void /* PRIVATE */
+png_init_rgb_transformations(png_structrp png_ptr)
+{
+ /* Added to libpng-1.5.4: check the color type to determine whether there
+ * is any alpha or transparency in the image and simply cancel the
+ * background and alpha mode stuff if there isn't.
+ */
+ int input_has_alpha = (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0;
+ int input_has_transparency = png_ptr->num_trans > 0;
+
+ /* If no alpha we can optimize. */
+ if (input_has_alpha == 0)
+ {
+ /* Any alpha means background and associative alpha processing is
+ * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA
+ * and ENCODE_ALPHA are irrelevant.
+ */
+# ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+ png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+ png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+# endif
+
+ if (input_has_transparency == 0)
+ png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND);
+ }
+
+#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
+ /* png_set_background handling - deals with the complexity of whether the
+ * background color is in the file format or the screen format in the case
+ * where an 'expand' will happen.
+ */
+
+ /* The following code cannot be entered in the alpha pre-multiplication case
+ * because PNG_BACKGROUND_EXPAND is cancelled below.
+ */
+ if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0 &&
+ (png_ptr->transformations & PNG_EXPAND) != 0 &&
+ (png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0)
+ /* i.e., GRAY or GRAY_ALPHA */
+ {
+ {
+ /* Expand background and tRNS chunks */
+ int gray = png_ptr->background.gray;
+ int trans_gray = png_ptr->trans_color.gray;
+
+ switch (png_ptr->bit_depth)
+ {
+ case 1:
+ gray *= 0xff;
+ trans_gray *= 0xff;
+ break;
+
+ case 2:
+ gray *= 0x55;
+ trans_gray *= 0x55;
+ break;
+
+ case 4:
+ gray *= 0x11;
+ trans_gray *= 0x11;
+ break;
+
+ default:
+
+ case 8:
+ /* FALLTHROUGH */ /* (Already 8 bits) */
+
+ case 16:
+ /* Already a full 16 bits */
+ break;
+ }
+
+ png_ptr->background.red = png_ptr->background.green =
+ png_ptr->background.blue = (png_uint_16)gray;
+
+ if ((png_ptr->transformations & PNG_EXPAND_tRNS) == 0)
+ {
+ png_ptr->trans_color.red = png_ptr->trans_color.green =
+ png_ptr->trans_color.blue = (png_uint_16)trans_gray;
+ }
+ }
+ } /* background expand and (therefore) no alpha association. */
+#endif /* READ_EXPAND && READ_BACKGROUND */
+}
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+png_fixed_point /* PRIVATE */
+png_resolve_file_gamma(png_const_structrp png_ptr)
+{
+ png_fixed_point file_gamma;
+
+ /* The file gamma is determined by these precedence rules, in this order
+ * (i.e. use the first value found):
+ *
+ * png_set_gamma; png_struct::file_gammma if not zero, then:
+ * png_struct::chunk_gamma if not 0 (determined the PNGv3 rules), then:
+ * png_set_gamma; 1/png_struct::screen_gamma if not zero
+ *
+ * 0 (i.e. do no gamma handling)
+ */
+ file_gamma = png_ptr->file_gamma;
+ if (file_gamma != 0)
+ return file_gamma;
+
+ file_gamma = png_ptr->chunk_gamma;
+ if (file_gamma != 0)
+ return file_gamma;
+
+ file_gamma = png_ptr->default_gamma;
+ if (file_gamma != 0)
+ return file_gamma;
+
+ /* If png_reciprocal oveflows it returns 0 which indicates to the caller that
+ * there is no usable file gamma. (The checks added to png_set_gamma and
+ * png_set_alpha_mode should prevent a screen_gamma which would overflow.)
+ */
+ if (png_ptr->screen_gamma != 0)
+ file_gamma = png_reciprocal(png_ptr->screen_gamma);
+
+ return file_gamma;
+}
+
+static int
+png_init_gamma_values(png_structrp png_ptr)
+{
+ /* The following temporary indicates if overall gamma correction is
+ * required.
+ */
+ int gamma_correction = 0;
+ png_fixed_point file_gamma, screen_gamma;
+
+ /* Resolve the file_gamma. See above: if png_ptr::screen_gamma is set
+ * file_gamma will always be set here:
+ */
+ file_gamma = png_resolve_file_gamma(png_ptr);
+ screen_gamma = png_ptr->screen_gamma;
+
+ if (file_gamma > 0) /* file has been set */
+ {
+ if (screen_gamma > 0) /* screen set too */
+ gamma_correction = png_gamma_threshold(file_gamma, screen_gamma);
+
+ else
+ /* Assume the output matches the input; a long time default behavior
+ * of libpng, although the standard has nothing to say about this.
+ */
+ screen_gamma = png_reciprocal(file_gamma);
+ }
+
+ else /* both unset, prevent corrections: */
+ file_gamma = screen_gamma = PNG_FP_1;
+
+ png_ptr->file_gamma = file_gamma;
+ png_ptr->screen_gamma = screen_gamma;
+ return gamma_correction;
+
+}
+#endif /* READ_GAMMA */
+
+void /* PRIVATE */
+png_init_read_transformations(png_structrp png_ptr)
+{
+ png_debug(1, "in png_init_read_transformations");
+
+ /* This internal function is called from png_read_start_row in pngrutil.c
+ * and it is called before the 'rowbytes' calculation is done, so the code
+ * in here can change or update the transformations flags.
+ *
+ * First do updates that do not depend on the details of the PNG image data
+ * being processed.
+ */
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ /* Prior to 1.5.4 these tests were performed from png_set_gamma, 1.5.4 adds
+ * png_set_alpha_mode and this is another source for a default file gamma so
+ * the test needs to be performed later - here. In addition prior to 1.5.4
+ * the tests were repeated for the PALETTE color type here - this is no
+ * longer necessary (and doesn't seem to have been necessary before.)
+ *
+ * PNGv3: the new mandatory precedence/priority rules for colour space chunks
+ * are handled here (by calling the above function).
+ *
+ * Turn the gamma transformation on or off as appropriate. Notice that
+ * PNG_GAMMA just refers to the file->screen correction. Alpha composition
+ * may independently cause gamma correction because it needs linear data
+ * (e.g. if the file has a gAMA chunk but the screen gamma hasn't been
+ * specified.) In any case this flag may get turned off in the code
+ * immediately below if the transform can be handled outside the row loop.
+ */
+ if (png_init_gamma_values(png_ptr) != 0)
+ png_ptr->transformations |= PNG_GAMMA;
+
+ else
+ png_ptr->transformations &= ~PNG_GAMMA;
+#endif
+
+ /* Certain transformations have the effect of preventing other
+ * transformations that happen afterward in png_do_read_transformations;
+ * resolve the interdependencies here. From the code of
+ * png_do_read_transformations the order is:
+ *
+ * 1) PNG_EXPAND (including PNG_EXPAND_tRNS)
+ * 2) PNG_STRIP_ALPHA (if no compose)
+ * 3) PNG_RGB_TO_GRAY
+ * 4) PNG_GRAY_TO_RGB iff !PNG_BACKGROUND_IS_GRAY
+ * 5) PNG_COMPOSE
+ * 6) PNG_GAMMA
+ * 7) PNG_STRIP_ALPHA (if compose)
+ * 8) PNG_ENCODE_ALPHA
+ * 9) PNG_SCALE_16_TO_8
+ * 10) PNG_16_TO_8
+ * 11) PNG_QUANTIZE (converts to palette)
+ * 12) PNG_EXPAND_16
+ * 13) PNG_GRAY_TO_RGB iff PNG_BACKGROUND_IS_GRAY
+ * 14) PNG_INVERT_MONO
+ * 15) PNG_INVERT_ALPHA
+ * 16) PNG_SHIFT
+ * 17) PNG_PACK
+ * 18) PNG_BGR
+ * 19) PNG_PACKSWAP
+ * 20) PNG_FILLER (includes PNG_ADD_ALPHA)
+ * 21) PNG_SWAP_ALPHA
+ * 22) PNG_SWAP_BYTES
+ * 23) PNG_USER_TRANSFORM [must be last]
+ */
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+ if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 &&
+ (png_ptr->transformations & PNG_COMPOSE) == 0)
+ {
+ /* Stripping the alpha channel happens immediately after the 'expand'
+ * transformations, before all other transformation, so it cancels out
+ * the alpha handling. It has the side effect negating the effect of
+ * PNG_EXPAND_tRNS too:
+ */
+ png_ptr->transformations &= ~(PNG_BACKGROUND_EXPAND | PNG_ENCODE_ALPHA |
+ PNG_EXPAND_tRNS);
+ png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+
+ /* Kill the tRNS chunk itself too. Prior to 1.5.4 this did not happen
+ * so transparency information would remain just so long as it wasn't
+ * expanded. This produces unexpected API changes if the set of things
+ * that do PNG_EXPAND_tRNS changes (perfectly possible given the
+ * documentation - which says ask for what you want, accept what you
+ * get.) This makes the behavior consistent from 1.5.4:
+ */
+ png_ptr->num_trans = 0;
+ }
+#endif /* STRIP_ALPHA supported, no COMPOSE */
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+ /* If the screen gamma is about 1.0 then the OPTIMIZE_ALPHA and ENCODE_ALPHA
+ * settings will have no effect.
+ */
+ if (png_gamma_significant(png_ptr->screen_gamma) == 0)
+ {
+ png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+ png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+ }
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ /* Make sure the coefficients for the rgb to gray conversion are set
+ * appropriately.
+ */
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
+ png_set_rgb_coefficients(png_ptr);
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
+ /* Detect gray background and attempt to enable optimization for
+ * gray --> RGB case.
+ *
+ * Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or
+ * RGB_ALPHA (in which case need_expand is superfluous anyway), the
+ * background color might actually be gray yet not be flagged as such.
+ * This is not a problem for the current code, which uses
+ * PNG_BACKGROUND_IS_GRAY only to decide when to do the
+ * png_do_gray_to_rgb() transformation.
+ *
+ * TODO: this code needs to be revised to avoid the complexity and
+ * interdependencies. The color type of the background should be recorded in
+ * png_set_background, along with the bit depth, then the code has a record
+ * of exactly what color space the background is currently in.
+ */
+ if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0)
+ {
+ /* PNG_BACKGROUND_EXPAND: the background is in the file color space, so if
+ * the file was grayscale the background value is gray.
+ */
+ if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0)
+ png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
+ }
+
+ else if ((png_ptr->transformations & PNG_COMPOSE) != 0)
+ {
+ /* PNG_COMPOSE: png_set_background was called with need_expand false,
+ * so the color is in the color space of the output or png_set_alpha_mode
+ * was called and the color is black. Ignore RGB_TO_GRAY because that
+ * happens before GRAY_TO_RGB.
+ */
+ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0)
+ {
+ if (png_ptr->background.red == png_ptr->background.green &&
+ png_ptr->background.red == png_ptr->background.blue)
+ {
+ png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
+ png_ptr->background.gray = png_ptr->background.red;
+ }
+ }
+ }
+#endif /* READ_EXPAND && READ_BACKGROUND */
+#endif /* READ_GRAY_TO_RGB */
+
+ /* For indexed PNG data (PNG_COLOR_TYPE_PALETTE) many of the transformations
+ * can be performed directly on the palette, and some (such as rgb to gray)
+ * can be optimized inside the palette. This is particularly true of the
+ * composite (background and alpha) stuff, which can be pretty much all done
+ * in the palette even if the result is expanded to RGB or gray afterward.
+ *
+ * NOTE: this is Not Yet Implemented, the code behaves as in 1.5.1 and
+ * earlier and the palette stuff is actually handled on the first row. This
+ * leads to the reported bug that the palette returned by png_get_PLTE is not
+ * updated.
+ */
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ png_init_palette_transformations(png_ptr);
+
+ else
+ png_init_rgb_transformations(png_ptr);
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
+ defined(PNG_READ_EXPAND_16_SUPPORTED)
+ if ((png_ptr->transformations & PNG_EXPAND_16) != 0 &&
+ (png_ptr->transformations & PNG_COMPOSE) != 0 &&
+ (png_ptr->transformations & PNG_BACKGROUND_EXPAND) == 0 &&
+ png_ptr->bit_depth != 16)
+ {
+ /* TODO: fix this. Because the expand_16 operation is after the compose
+ * handling the background color must be 8, not 16, bits deep, but the
+ * application will supply a 16-bit value so reduce it here.
+ *
+ * The PNG_BACKGROUND_EXPAND code above does not expand to 16 bits at
+ * present, so that case is ok (until do_expand_16 is moved.)
+ *
+ * NOTE: this discards the low 16 bits of the user supplied background
+ * color, but until expand_16 works properly there is no choice!
+ */
+# define CHOP(x) (x)=((png_uint_16)PNG_DIV257(x))
+ CHOP(png_ptr->background.red);
+ CHOP(png_ptr->background.green);
+ CHOP(png_ptr->background.blue);
+ CHOP(png_ptr->background.gray);
+# undef CHOP
+ }
+#endif /* READ_BACKGROUND && READ_EXPAND_16 */
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
+ (defined(PNG_READ_SCALE_16_TO_8_SUPPORTED) || \
+ defined(PNG_READ_STRIP_16_TO_8_SUPPORTED))
+ if ((png_ptr->transformations & (PNG_16_TO_8|PNG_SCALE_16_TO_8)) != 0 &&
+ (png_ptr->transformations & PNG_COMPOSE) != 0 &&
+ (png_ptr->transformations & PNG_BACKGROUND_EXPAND) == 0 &&
+ png_ptr->bit_depth == 16)
+ {
+ /* On the other hand, if a 16-bit file is to be reduced to 8-bits per
+ * component this will also happen after PNG_COMPOSE and so the background
+ * color must be pre-expanded here.
+ *
+ * TODO: fix this too.
+ */
+ png_ptr->background.red = (png_uint_16)(png_ptr->background.red * 257);
+ png_ptr->background.green =
+ (png_uint_16)(png_ptr->background.green * 257);
+ png_ptr->background.blue = (png_uint_16)(png_ptr->background.blue * 257);
+ png_ptr->background.gray = (png_uint_16)(png_ptr->background.gray * 257);
+ }
+#endif
+
+ /* NOTE: below 'PNG_READ_ALPHA_MODE_SUPPORTED' is presumed to also enable the
+ * background support (see the comments in scripts/pnglibconf.dfa), this
+ * allows pre-multiplication of the alpha channel to be implemented as
+ * compositing on black. This is probably sub-optimal and has been done in
+ * 1.5.4 betas simply to enable external critique and testing (i.e. to
+ * implement the new API quickly, without lots of internal changes.)
+ */
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+# ifdef PNG_READ_BACKGROUND_SUPPORTED
+ /* Includes ALPHA_MODE */
+ png_ptr->background_1 = png_ptr->background;
+# endif
+
+ /* This needs to change - in the palette image case a whole set of tables are
+ * built when it would be quicker to just calculate the correct value for
+ * each palette entry directly. Also, the test is too tricky - why check
+ * PNG_RGB_TO_GRAY if PNG_GAMMA is not set? The answer seems to be that
+ * PNG_GAMMA is cancelled even if the gamma is known? The test excludes the
+ * PNG_COMPOSE case, so apparently if there is no *overall* gamma correction
+ * the gamma tables will not be built even if composition is required on a
+ * gamma encoded value.
+ *
+ * In 1.5.4 this is addressed below by an additional check on the individual
+ * file gamma - if it is not 1.0 both RGB_TO_GRAY and COMPOSE need the
+ * tables.
+ */
+ if ((png_ptr->transformations & PNG_GAMMA) != 0 ||
+ ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0 &&
+ (png_gamma_significant(png_ptr->file_gamma) != 0 ||
+ png_gamma_significant(png_ptr->screen_gamma) != 0)) ||
+ ((png_ptr->transformations & PNG_COMPOSE) != 0 &&
+ (png_gamma_significant(png_ptr->file_gamma) != 0 ||
+ png_gamma_significant(png_ptr->screen_gamma) != 0
+# ifdef PNG_READ_BACKGROUND_SUPPORTED
+ || (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_UNIQUE &&
+ png_gamma_significant(png_ptr->background_gamma) != 0)
+# endif
+ )) || ((png_ptr->transformations & PNG_ENCODE_ALPHA) != 0 &&
+ png_gamma_significant(png_ptr->screen_gamma) != 0))
+ {
+ png_build_gamma_table(png_ptr, png_ptr->bit_depth);
+
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+ if ((png_ptr->transformations & PNG_COMPOSE) != 0)
+ {
+ /* Issue a warning about this combination: because RGB_TO_GRAY is
+ * optimized to do the gamma transform if present yet do_background has
+ * to do the same thing if both options are set a
+ * double-gamma-correction happens. This is true in all versions of
+ * libpng to date.
+ */
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
+ png_warning(png_ptr,
+ "libpng does not support gamma+background+rgb_to_gray");
+
+ if ((png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) != 0)
+ {
+ /* We don't get to here unless there is a tRNS chunk with non-opaque
+ * entries - see the checking code at the start of this function.
+ */
+ png_color back, back_1;
+ png_colorp palette = png_ptr->palette;
+ int num_palette = png_ptr->num_palette;
+ int i;
+ if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)
+ {
+
+ back.red = png_ptr->gamma_table[png_ptr->background.red];
+ back.green = png_ptr->gamma_table[png_ptr->background.green];
+ back.blue = png_ptr->gamma_table[png_ptr->background.blue];
+
+ back_1.red = png_ptr->gamma_to_1[png_ptr->background.red];
+ back_1.green = png_ptr->gamma_to_1[png_ptr->background.green];
+ back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue];
+ }
+ else
+ {
+ png_fixed_point g, gs;
+
+ switch (png_ptr->background_gamma_type)
+ {
+ case PNG_BACKGROUND_GAMMA_SCREEN:
+ g = (png_ptr->screen_gamma);
+ gs = PNG_FP_1;
+ break;
+
+ case PNG_BACKGROUND_GAMMA_FILE:
+ g = png_reciprocal(png_ptr->file_gamma);
+ gs = png_reciprocal2(png_ptr->file_gamma,
+ png_ptr->screen_gamma);
+ break;
+
+ case PNG_BACKGROUND_GAMMA_UNIQUE:
+ g = png_reciprocal(png_ptr->background_gamma);
+ gs = png_reciprocal2(png_ptr->background_gamma,
+ png_ptr->screen_gamma);
+ break;
+ default:
+ g = PNG_FP_1; /* back_1 */
+ gs = PNG_FP_1; /* back */
+ break;
+ }
+
+ if (png_gamma_significant(gs) != 0)
+ {
+ back.red = png_gamma_8bit_correct(png_ptr->background.red,
+ gs);
+ back.green = png_gamma_8bit_correct(png_ptr->background.green,
+ gs);
+ back.blue = png_gamma_8bit_correct(png_ptr->background.blue,
+ gs);
+ }
+
+ else
+ {
+ back.red = (png_byte)png_ptr->background.red;
+ back.green = (png_byte)png_ptr->background.green;
+ back.blue = (png_byte)png_ptr->background.blue;
+ }
+
+ if (png_gamma_significant(g) != 0)
+ {
+ back_1.red = png_gamma_8bit_correct(png_ptr->background.red,
+ g);
+ back_1.green = png_gamma_8bit_correct(
+ png_ptr->background.green, g);
+ back_1.blue = png_gamma_8bit_correct(png_ptr->background.blue,
+ g);
+ }
+
+ else
+ {
+ back_1.red = (png_byte)png_ptr->background.red;
+ back_1.green = (png_byte)png_ptr->background.green;
+ back_1.blue = (png_byte)png_ptr->background.blue;
+ }
+ }
+
+ for (i = 0; i < num_palette; i++)
+ {
+ if (i < (int)png_ptr->num_trans &&
+ png_ptr->trans_alpha[i] != 0xff)
+ {
+ if (png_ptr->trans_alpha[i] == 0)
+ {
+ palette[i] = back;
+ }
+ else /* if (png_ptr->trans_alpha[i] != 0xff) */
+ {
+ png_byte v, w;
+
+ v = png_ptr->gamma_to_1[palette[i].red];
+ png_composite(w, v, png_ptr->trans_alpha[i], back_1.red);
+ palette[i].red = png_ptr->gamma_from_1[w];
+
+ v = png_ptr->gamma_to_1[palette[i].green];
+ png_composite(w, v, png_ptr->trans_alpha[i], back_1.green);
+ palette[i].green = png_ptr->gamma_from_1[w];
+
+ v = png_ptr->gamma_to_1[palette[i].blue];
+ png_composite(w, v, png_ptr->trans_alpha[i], back_1.blue);
+ palette[i].blue = png_ptr->gamma_from_1[w];
+ }
+ }
+ else
+ {
+ palette[i].red = png_ptr->gamma_table[palette[i].red];
+ palette[i].green = png_ptr->gamma_table[palette[i].green];
+ palette[i].blue = png_ptr->gamma_table[palette[i].blue];
+ }
+ }
+
+ /* Prevent the transformations being done again.
+ *
+ * NOTE: this is highly dubious; it removes the transformations in
+ * place. This seems inconsistent with the general treatment of the
+ * transformations elsewhere.
+ */
+ png_ptr->transformations &= ~(PNG_COMPOSE | PNG_GAMMA);
+ } /* color_type == PNG_COLOR_TYPE_PALETTE */
+
+ /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */
+ else /* color_type != PNG_COLOR_TYPE_PALETTE */
+ {
+ int gs_sig, g_sig;
+ png_fixed_point g = PNG_FP_1; /* Correction to linear */
+ png_fixed_point gs = PNG_FP_1; /* Correction to screen */
+
+ switch (png_ptr->background_gamma_type)
+ {
+ case PNG_BACKGROUND_GAMMA_SCREEN:
+ g = png_ptr->screen_gamma;
+ /* gs = PNG_FP_1; */
+ break;
+
+ case PNG_BACKGROUND_GAMMA_FILE:
+ g = png_reciprocal(png_ptr->file_gamma);
+ gs = png_reciprocal2(png_ptr->file_gamma,
+ png_ptr->screen_gamma);
+ break;
+
+ case PNG_BACKGROUND_GAMMA_UNIQUE:
+ g = png_reciprocal(png_ptr->background_gamma);
+ gs = png_reciprocal2(png_ptr->background_gamma,
+ png_ptr->screen_gamma);
+ break;
+
+ default:
+ png_error(png_ptr, "invalid background gamma type");
+ }
+
+ g_sig = png_gamma_significant(g);
+ gs_sig = png_gamma_significant(gs);
+
+ if (g_sig != 0)
+ png_ptr->background_1.gray = png_gamma_correct(png_ptr,
+ png_ptr->background.gray, g);
+
+ if (gs_sig != 0)
+ png_ptr->background.gray = png_gamma_correct(png_ptr,
+ png_ptr->background.gray, gs);
+
+ if ((png_ptr->background.red != png_ptr->background.green) ||
+ (png_ptr->background.red != png_ptr->background.blue) ||
+ (png_ptr->background.red != png_ptr->background.gray))
+ {
+ /* RGB or RGBA with color background */
+ if (g_sig != 0)
+ {
+ png_ptr->background_1.red = png_gamma_correct(png_ptr,
+ png_ptr->background.red, g);
+
+ png_ptr->background_1.green = png_gamma_correct(png_ptr,
+ png_ptr->background.green, g);
+
+ png_ptr->background_1.blue = png_gamma_correct(png_ptr,
+ png_ptr->background.blue, g);
+ }
+
+ if (gs_sig != 0)
+ {
+ png_ptr->background.red = png_gamma_correct(png_ptr,
+ png_ptr->background.red, gs);
+
+ png_ptr->background.green = png_gamma_correct(png_ptr,
+ png_ptr->background.green, gs);
+
+ png_ptr->background.blue = png_gamma_correct(png_ptr,
+ png_ptr->background.blue, gs);
+ }
+ }
+
+ else
+ {
+ /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */
+ png_ptr->background_1.red = png_ptr->background_1.green
+ = png_ptr->background_1.blue = png_ptr->background_1.gray;
+
+ png_ptr->background.red = png_ptr->background.green
+ = png_ptr->background.blue = png_ptr->background.gray;
+ }
+
+ /* The background is now in screen gamma: */
+ png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_SCREEN;
+ } /* color_type != PNG_COLOR_TYPE_PALETTE */
+ }/* png_ptr->transformations & PNG_BACKGROUND */
+
+ else
+ /* Transformation does not include PNG_BACKGROUND */
+#endif /* READ_BACKGROUND */
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ /* RGB_TO_GRAY needs to have non-gamma-corrected values! */
+ && ((png_ptr->transformations & PNG_EXPAND) == 0 ||
+ (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0)
+#endif
+ )
+ {
+ png_colorp palette = png_ptr->palette;
+ int num_palette = png_ptr->num_palette;
+ int i;
+
+ /* NOTE: there are other transformations that should probably be in
+ * here too.
+ */
+ for (i = 0; i < num_palette; i++)
+ {
+ palette[i].red = png_ptr->gamma_table[palette[i].red];
+ palette[i].green = png_ptr->gamma_table[palette[i].green];
+ palette[i].blue = png_ptr->gamma_table[palette[i].blue];
+ }
+
+ /* Done the gamma correction. */
+ png_ptr->transformations &= ~PNG_GAMMA;
+ } /* color_type == PALETTE && !PNG_BACKGROUND transformation */
+ }
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+ else
+#endif
+#endif /* READ_GAMMA */
+
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+ /* No GAMMA transformation (see the hanging else 4 lines above) */
+ if ((png_ptr->transformations & PNG_COMPOSE) != 0 &&
+ (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
+ {
+ int i;
+ int istop = (int)png_ptr->num_trans;
+ png_color back;
+ png_colorp palette = png_ptr->palette;
+
+ back.red = (png_byte)png_ptr->background.red;
+ back.green = (png_byte)png_ptr->background.green;
+ back.blue = (png_byte)png_ptr->background.blue;
+
+ for (i = 0; i < istop; i++)
+ {
+ if (png_ptr->trans_alpha[i] == 0)
+ {
+ palette[i] = back;
+ }
+
+ else if (png_ptr->trans_alpha[i] != 0xff)
+ {
+ /* The png_composite() macro is defined in png.h */
+ png_composite(palette[i].red, palette[i].red,
+ png_ptr->trans_alpha[i], back.red);
+
+ png_composite(palette[i].green, palette[i].green,
+ png_ptr->trans_alpha[i], back.green);
+
+ png_composite(palette[i].blue, palette[i].blue,
+ png_ptr->trans_alpha[i], back.blue);
+ }
+ }
+
+ png_ptr->transformations &= ~PNG_COMPOSE;
+ }
+#endif /* READ_BACKGROUND */
+
+#ifdef PNG_READ_SHIFT_SUPPORTED
+ if ((png_ptr->transformations & PNG_SHIFT) != 0 &&
+ (png_ptr->transformations & PNG_EXPAND) == 0 &&
+ (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
+ {
+ int i;
+ int istop = png_ptr->num_palette;
+ int shift = 8 - png_ptr->sig_bit.red;
+
+ png_ptr->transformations &= ~PNG_SHIFT;
+
+ /* significant bits can be in the range 1 to 7 for a meaningful result, if
+ * the number of significant bits is 0 then no shift is done (this is an
+ * error condition which is silently ignored.)
+ */
+ if (shift > 0 && shift < 8)
+ for (i=0; ipalette[i].red;
+
+ component >>= shift;
+ png_ptr->palette[i].red = (png_byte)component;
+ }
+
+ shift = 8 - png_ptr->sig_bit.green;
+ if (shift > 0 && shift < 8)
+ for (i=0; ipalette[i].green;
+
+ component >>= shift;
+ png_ptr->palette[i].green = (png_byte)component;
+ }
+
+ shift = 8 - png_ptr->sig_bit.blue;
+ if (shift > 0 && shift < 8)
+ for (i=0; ipalette[i].blue;
+
+ component >>= shift;
+ png_ptr->palette[i].blue = (png_byte)component;
+ }
+ }
+#endif /* READ_SHIFT */
+}
+
+/* Modify the info structure to reflect the transformations. The
+ * info should be updated so a PNG file could be written with it,
+ * assuming the transformations result in valid PNG data.
+ */
+void /* PRIVATE */
+png_read_transform_info(png_structrp png_ptr, png_inforp info_ptr)
+{
+ png_debug(1, "in png_read_transform_info");
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ if ((png_ptr->transformations & PNG_EXPAND) != 0)
+ {
+ if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ /* This check must match what actually happens in
+ * png_do_expand_palette; if it ever checks the tRNS chunk to see if
+ * it is all opaque we must do the same (at present it does not.)
+ */
+ if (png_ptr->num_trans > 0)
+ info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+
+ else
+ info_ptr->color_type = PNG_COLOR_TYPE_RGB;
+
+ info_ptr->bit_depth = 8;
+ info_ptr->num_trans = 0;
+
+ if (png_ptr->palette == NULL)
+ png_error (png_ptr, "Palette is NULL in indexed image");
+ }
+ else
+ {
+ if (png_ptr->num_trans != 0)
+ {
+ if ((png_ptr->transformations & PNG_EXPAND_tRNS) != 0)
+ info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
+ }
+ if (info_ptr->bit_depth < 8)
+ info_ptr->bit_depth = 8;
+
+ info_ptr->num_trans = 0;
+ }
+ }
+#endif
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+ defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+ /* The following is almost certainly wrong unless the background value is in
+ * the screen space!
+ */
+ if ((png_ptr->transformations & PNG_COMPOSE) != 0)
+ info_ptr->background = png_ptr->background;
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ /* The following used to be conditional on PNG_GAMMA (prior to 1.5.4),
+ * however it seems that the code in png_init_read_transformations, which has
+ * been called before this from png_read_update_info->png_read_start_row
+ * sometimes does the gamma transform and cancels the flag.
+ *
+ * TODO: this is confusing. It only changes the result of png_get_gAMA and,
+ * yes, it does return the value that the transformed data effectively has
+ * but does any app really understand this?
+ */
+ info_ptr->gamma = png_ptr->file_gamma;
+#endif
+
+ if (info_ptr->bit_depth == 16)
+ {
+# ifdef PNG_READ_16BIT_SUPPORTED
+# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+ if ((png_ptr->transformations & PNG_SCALE_16_TO_8) != 0)
+ info_ptr->bit_depth = 8;
+# endif
+
+# ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+ if ((png_ptr->transformations & PNG_16_TO_8) != 0)
+ info_ptr->bit_depth = 8;
+# endif
+
+# else
+ /* No 16-bit support: force chopping 16-bit input down to 8, in this case
+ * the app program can chose if both APIs are available by setting the
+ * correct scaling to use.
+ */
+# ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+ /* For compatibility with previous versions use the strip method by
+ * default. This code works because if PNG_SCALE_16_TO_8 is already
+ * set the code below will do that in preference to the chop.
+ */
+ png_ptr->transformations |= PNG_16_TO_8;
+ info_ptr->bit_depth = 8;
+# else
+
+# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+ png_ptr->transformations |= PNG_SCALE_16_TO_8;
+ info_ptr->bit_depth = 8;
+# else
+
+ CONFIGURATION ERROR: you must enable at least one 16 to 8 method
+# endif
+# endif
+#endif /* !READ_16BIT */
+ }
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0)
+ info_ptr->color_type = (png_byte)(info_ptr->color_type |
+ PNG_COLOR_MASK_COLOR);
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
+ info_ptr->color_type = (png_byte)(info_ptr->color_type &
+ ~PNG_COLOR_MASK_COLOR);
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+ if ((png_ptr->transformations & PNG_QUANTIZE) != 0)
+ {
+ if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
+ (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) &&
+ png_ptr->palette_lookup != 0 && info_ptr->bit_depth == 8)
+ {
+ info_ptr->color_type = PNG_COLOR_TYPE_PALETTE;
+ }
+ }
+#endif
+
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+ if ((png_ptr->transformations & PNG_EXPAND_16) != 0 &&
+ info_ptr->bit_depth == 8 &&
+ info_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
+ {
+ info_ptr->bit_depth = 16;
+ }
+#endif
+
+#ifdef PNG_READ_PACK_SUPPORTED
+ if ((png_ptr->transformations & PNG_PACK) != 0 &&
+ (info_ptr->bit_depth < 8))
+ info_ptr->bit_depth = 8;
+#endif
+
+ if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ info_ptr->channels = 1;
+
+ else if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ info_ptr->channels = 3;
+
+ else
+ info_ptr->channels = 1;
+
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+ if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0)
+ {
+ info_ptr->color_type = (png_byte)(info_ptr->color_type &
+ ~PNG_COLOR_MASK_ALPHA);
+ info_ptr->num_trans = 0;
+ }
+#endif
+
+ if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+ info_ptr->channels++;
+
+#ifdef PNG_READ_FILLER_SUPPORTED
+ /* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */
+ if ((png_ptr->transformations & PNG_FILLER) != 0 &&
+ (info_ptr->color_type == PNG_COLOR_TYPE_RGB ||
+ info_ptr->color_type == PNG_COLOR_TYPE_GRAY))
+ {
+ info_ptr->channels++;
+ /* If adding a true alpha channel not just filler */
+ if ((png_ptr->transformations & PNG_ADD_ALPHA) != 0)
+ info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
+ }
+#endif
+
+#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \
+defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
+ if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
+ {
+ if (png_ptr->user_transform_depth != 0)
+ info_ptr->bit_depth = png_ptr->user_transform_depth;
+
+ if (png_ptr->user_transform_channels != 0)
+ info_ptr->channels = png_ptr->user_transform_channels;
+ }
+#endif
+
+ info_ptr->pixel_depth = (png_byte)(info_ptr->channels *
+ info_ptr->bit_depth);
+
+ info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width);
+
+ /* Adding in 1.5.4: cache the above value in png_struct so that we can later
+ * check in png_rowbytes that the user buffer won't get overwritten. Note
+ * that the field is not always set - if png_read_update_info isn't called
+ * the application has to either not do any transforms or get the calculation
+ * right itself.
+ */
+ png_ptr->info_rowbytes = info_ptr->rowbytes;
+
+#ifndef PNG_READ_EXPAND_SUPPORTED
+ if (png_ptr != NULL)
+ return;
+#endif
+}
+
+#ifdef PNG_READ_PACK_SUPPORTED
+/* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel,
+ * without changing the actual values. Thus, if you had a row with
+ * a bit depth of 1, you would end up with bytes that only contained
+ * the numbers 0 or 1. If you would rather they contain 0 and 255, use
+ * png_do_shift() after this.
+ */
+static void
+png_do_unpack(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_unpack");
+
+ if (row_info->bit_depth < 8)
+ {
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+
+ switch (row_info->bit_depth)
+ {
+ case 1:
+ {
+ png_bytep sp = row + (size_t)((row_width - 1) >> 3);
+ png_bytep dp = row + (size_t)row_width - 1;
+ png_uint_32 shift = 7U - ((row_width + 7U) & 0x07);
+ for (i = 0; i < row_width; i++)
+ {
+ *dp = (png_byte)((*sp >> shift) & 0x01);
+
+ if (shift == 7)
+ {
+ shift = 0;
+ sp--;
+ }
+
+ else
+ shift++;
+
+ dp--;
+ }
+ break;
+ }
+
+ case 2:
+ {
+
+ png_bytep sp = row + (size_t)((row_width - 1) >> 2);
+ png_bytep dp = row + (size_t)row_width - 1;
+ png_uint_32 shift = ((3U - ((row_width + 3U) & 0x03)) << 1);
+ for (i = 0; i < row_width; i++)
+ {
+ *dp = (png_byte)((*sp >> shift) & 0x03);
+
+ if (shift == 6)
+ {
+ shift = 0;
+ sp--;
+ }
+
+ else
+ shift += 2;
+
+ dp--;
+ }
+ break;
+ }
+
+ case 4:
+ {
+ png_bytep sp = row + (size_t)((row_width - 1) >> 1);
+ png_bytep dp = row + (size_t)row_width - 1;
+ png_uint_32 shift = ((1U - ((row_width + 1U) & 0x01)) << 2);
+ for (i = 0; i < row_width; i++)
+ {
+ *dp = (png_byte)((*sp >> shift) & 0x0f);
+
+ if (shift == 4)
+ {
+ shift = 0;
+ sp--;
+ }
+
+ else
+ shift = 4;
+
+ dp--;
+ }
+ break;
+ }
+
+ default:
+ break;
+ }
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = (png_byte)(8 * row_info->channels);
+ row_info->rowbytes = row_width * row_info->channels;
+ }
+}
+#endif
+
+#ifdef PNG_READ_SHIFT_SUPPORTED
+/* Reverse the effects of png_do_shift. This routine merely shifts the
+ * pixels back to their significant bits values. Thus, if you have
+ * a row of bit depth 8, but only 5 are significant, this will shift
+ * the values back to 0 through 31.
+ */
+static void
+png_do_unshift(png_row_infop row_info, png_bytep row,
+ png_const_color_8p sig_bits)
+{
+ int color_type;
+
+ png_debug(1, "in png_do_unshift");
+
+ /* The palette case has already been handled in the _init routine. */
+ color_type = row_info->color_type;
+
+ if (color_type != PNG_COLOR_TYPE_PALETTE)
+ {
+ int shift[4];
+ int channels = 0;
+ int bit_depth = row_info->bit_depth;
+
+ if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
+ {
+ shift[channels++] = bit_depth - sig_bits->red;
+ shift[channels++] = bit_depth - sig_bits->green;
+ shift[channels++] = bit_depth - sig_bits->blue;
+ }
+
+ else
+ {
+ shift[channels++] = bit_depth - sig_bits->gray;
+ }
+
+ if ((color_type & PNG_COLOR_MASK_ALPHA) != 0)
+ {
+ shift[channels++] = bit_depth - sig_bits->alpha;
+ }
+
+ {
+ int c, have_shift;
+
+ for (c = have_shift = 0; c < channels; ++c)
+ {
+ /* A shift of more than the bit depth is an error condition but it
+ * gets ignored here.
+ */
+ if (shift[c] <= 0 || shift[c] >= bit_depth)
+ shift[c] = 0;
+
+ else
+ have_shift = 1;
+ }
+
+ if (have_shift == 0)
+ return;
+ }
+
+ switch (bit_depth)
+ {
+ default:
+ /* Must be 1bpp gray: should not be here! */
+ /* NOTREACHED */
+ break;
+
+ case 2:
+ /* Must be 2bpp gray */
+ /* assert(channels == 1 && shift[0] == 1) */
+ {
+ png_bytep bp = row;
+ png_bytep bp_end = bp + row_info->rowbytes;
+
+ while (bp < bp_end)
+ {
+ int b = (*bp >> 1) & 0x55;
+ *bp++ = (png_byte)b;
+ }
+ break;
+ }
+
+ case 4:
+ /* Must be 4bpp gray */
+ /* assert(channels == 1) */
+ {
+ png_bytep bp = row;
+ png_bytep bp_end = bp + row_info->rowbytes;
+ int gray_shift = shift[0];
+ int mask = 0xf >> gray_shift;
+
+ mask |= mask << 4;
+
+ while (bp < bp_end)
+ {
+ int b = (*bp >> gray_shift) & mask;
+ *bp++ = (png_byte)b;
+ }
+ break;
+ }
+
+ case 8:
+ /* Single byte components, G, GA, RGB, RGBA */
+ {
+ png_bytep bp = row;
+ png_bytep bp_end = bp + row_info->rowbytes;
+ int channel = 0;
+
+ while (bp < bp_end)
+ {
+ int b = *bp >> shift[channel];
+ if (++channel >= channels)
+ channel = 0;
+ *bp++ = (png_byte)b;
+ }
+ break;
+ }
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+ case 16:
+ /* Double byte components, G, GA, RGB, RGBA */
+ {
+ png_bytep bp = row;
+ png_bytep bp_end = bp + row_info->rowbytes;
+ int channel = 0;
+
+ while (bp < bp_end)
+ {
+ int value = (bp[0] << 8) + bp[1];
+
+ value >>= shift[channel];
+ if (++channel >= channels)
+ channel = 0;
+ *bp++ = (png_byte)(value >> 8);
+ *bp++ = (png_byte)value;
+ }
+ break;
+ }
+#endif
+ }
+ }
+}
+#endif
+
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+/* Scale rows of bit depth 16 down to 8 accurately */
+static void
+png_do_scale_16_to_8(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_scale_16_to_8");
+
+ if (row_info->bit_depth == 16)
+ {
+ png_bytep sp = row; /* source */
+ png_bytep dp = row; /* destination */
+ png_bytep ep = sp + row_info->rowbytes; /* end+1 */
+
+ while (sp < ep)
+ {
+ /* The input is an array of 16-bit components, these must be scaled to
+ * 8 bits each. For a 16-bit value V the required value (from the PNG
+ * specification) is:
+ *
+ * (V * 255) / 65535
+ *
+ * This reduces to round(V / 257), or floor((V + 128.5)/257)
+ *
+ * Represent V as the two byte value vhi.vlo. Make a guess that the
+ * result is the top byte of V, vhi, then the correction to this value
+ * is:
+ *
+ * error = floor(((V-vhi.vhi) + 128.5) / 257)
+ * = floor(((vlo-vhi) + 128.5) / 257)
+ *
+ * This can be approximated using integer arithmetic (and a signed
+ * shift):
+ *
+ * error = (vlo-vhi+128) >> 8;
+ *
+ * The approximate differs from the exact answer only when (vlo-vhi) is
+ * 128; it then gives a correction of +1 when the exact correction is
+ * 0. This gives 128 errors. The exact answer (correct for all 16-bit
+ * input values) is:
+ *
+ * error = (vlo-vhi+128)*65535 >> 24;
+ *
+ * An alternative arithmetic calculation which also gives no errors is:
+ *
+ * (V * 255 + 32895) >> 16
+ */
+
+ png_int_32 tmp = *sp++; /* must be signed! */
+ tmp += (((int)*sp++ - tmp + 128) * 65535) >> 24;
+ *dp++ = (png_byte)tmp;
+ }
+
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = (png_byte)(8 * row_info->channels);
+ row_info->rowbytes = row_info->width * row_info->channels;
+ }
+}
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+static void
+/* Simply discard the low byte. This was the default behavior prior
+ * to libpng-1.5.4.
+ */
+png_do_chop(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_chop");
+
+ if (row_info->bit_depth == 16)
+ {
+ png_bytep sp = row; /* source */
+ png_bytep dp = row; /* destination */
+ png_bytep ep = sp + row_info->rowbytes; /* end+1 */
+
+ while (sp < ep)
+ {
+ *dp++ = *sp;
+ sp += 2; /* skip low byte */
+ }
+
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = (png_byte)(8 * row_info->channels);
+ row_info->rowbytes = row_info->width * row_info->channels;
+ }
+}
+#endif
+
+#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
+static void
+png_do_read_swap_alpha(png_row_infop row_info, png_bytep row)
+{
+ png_uint_32 row_width = row_info->width;
+
+ png_debug(1, "in png_do_read_swap_alpha");
+
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ /* This converts from RGBA to ARGB */
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_byte save;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ save = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = save;
+ }
+ }
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+ /* This converts from RRGGBBAA to AARRGGBB */
+ else
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_byte save[2];
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ save[0] = *(--sp);
+ save[1] = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = save[0];
+ *(--dp) = save[1];
+ }
+ }
+#endif
+ }
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ /* This converts from GA to AG */
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_byte save;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ save = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = save;
+ }
+ }
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+ /* This converts from GGAA to AAGG */
+ else
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_byte save[2];
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ save[0] = *(--sp);
+ save[1] = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = save[0];
+ *(--dp) = save[1];
+ }
+ }
+#endif
+ }
+}
+#endif
+
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+static void
+png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
+{
+ png_uint_32 row_width;
+ png_debug(1, "in png_do_read_invert_alpha");
+
+ row_width = row_info->width;
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ /* This inverts the alpha channel in RGBA */
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = (png_byte)(255 - *(--sp));
+
+/* This does nothing:
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ We can replace it with:
+*/
+ sp-=3;
+ dp=sp;
+ }
+ }
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+ /* This inverts the alpha channel in RRGGBBAA */
+ else
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = (png_byte)(255 - *(--sp));
+ *(--dp) = (png_byte)(255 - *(--sp));
+
+/* This does nothing:
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ We can replace it with:
+*/
+ sp-=6;
+ dp=sp;
+ }
+ }
+#endif
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ /* This inverts the alpha channel in GA */
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = (png_byte)(255 - *(--sp));
+ *(--dp) = *(--sp);
+ }
+ }
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+ else
+ {
+ /* This inverts the alpha channel in GGAA */
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = (png_byte)(255 - *(--sp));
+ *(--dp) = (png_byte)(255 - *(--sp));
+/*
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+*/
+ sp-=2;
+ dp=sp;
+ }
+ }
+#endif
+ }
+}
+#endif
+
+#ifdef PNG_READ_FILLER_SUPPORTED
+/* Add filler channel if we have RGB color */
+static void
+png_do_read_filler(png_row_infop row_info, png_bytep row,
+ png_uint_32 filler, png_uint_32 flags)
+{
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+ png_byte hi_filler = (png_byte)(filler>>8);
+#endif
+ png_byte lo_filler = (png_byte)filler;
+
+ png_debug(1, "in png_do_read_filler");
+
+ if (
+ row_info->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
+ {
+ /* This changes the data from G to GX */
+ png_bytep sp = row + (size_t)row_width;
+ png_bytep dp = sp + (size_t)row_width;
+ for (i = 1; i < row_width; i++)
+ {
+ *(--dp) = lo_filler;
+ *(--dp) = *(--sp);
+ }
+ *(--dp) = lo_filler;
+ row_info->channels = 2;
+ row_info->pixel_depth = 16;
+ row_info->rowbytes = row_width * 2;
+ }
+
+ else
+ {
+ /* This changes the data from G to XG */
+ png_bytep sp = row + (size_t)row_width;
+ png_bytep dp = sp + (size_t)row_width;
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = *(--sp);
+ *(--dp) = lo_filler;
+ }
+ row_info->channels = 2;
+ row_info->pixel_depth = 16;
+ row_info->rowbytes = row_width * 2;
+ }
+ }
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+ else if (row_info->bit_depth == 16)
+ {
+ if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
+ {
+ /* This changes the data from GG to GGXX */
+ png_bytep sp = row + (size_t)row_width * 2;
+ png_bytep dp = sp + (size_t)row_width * 2;
+ for (i = 1; i < row_width; i++)
+ {
+ *(--dp) = lo_filler;
+ *(--dp) = hi_filler;
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ }
+ *(--dp) = lo_filler;
+ *(--dp) = hi_filler;
+ row_info->channels = 2;
+ row_info->pixel_depth = 32;
+ row_info->rowbytes = row_width * 4;
+ }
+
+ else
+ {
+ /* This changes the data from GG to XXGG */
+ png_bytep sp = row + (size_t)row_width * 2;
+ png_bytep dp = sp + (size_t)row_width * 2;
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = lo_filler;
+ *(--dp) = hi_filler;
+ }
+ row_info->channels = 2;
+ row_info->pixel_depth = 32;
+ row_info->rowbytes = row_width * 4;
+ }
+ }
+#endif
+ } /* COLOR_TYPE == GRAY */
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
+ {
+ /* This changes the data from RGB to RGBX */
+ png_bytep sp = row + (size_t)row_width * 3;
+ png_bytep dp = sp + (size_t)row_width;
+ for (i = 1; i < row_width; i++)
+ {
+ *(--dp) = lo_filler;
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ }
+ *(--dp) = lo_filler;
+ row_info->channels = 4;
+ row_info->pixel_depth = 32;
+ row_info->rowbytes = row_width * 4;
+ }
+
+ else
+ {
+ /* This changes the data from RGB to XRGB */
+ png_bytep sp = row + (size_t)row_width * 3;
+ png_bytep dp = sp + (size_t)row_width;
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = lo_filler;
+ }
+ row_info->channels = 4;
+ row_info->pixel_depth = 32;
+ row_info->rowbytes = row_width * 4;
+ }
+ }
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+ else if (row_info->bit_depth == 16)
+ {
+ if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
+ {
+ /* This changes the data from RRGGBB to RRGGBBXX */
+ png_bytep sp = row + (size_t)row_width * 6;
+ png_bytep dp = sp + (size_t)row_width * 2;
+ for (i = 1; i < row_width; i++)
+ {
+ *(--dp) = lo_filler;
+ *(--dp) = hi_filler;
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ }
+ *(--dp) = lo_filler;
+ *(--dp) = hi_filler;
+ row_info->channels = 4;
+ row_info->pixel_depth = 64;
+ row_info->rowbytes = row_width * 8;
+ }
+
+ else
+ {
+ /* This changes the data from RRGGBB to XXRRGGBB */
+ png_bytep sp = row + (size_t)row_width * 6;
+ png_bytep dp = sp + (size_t)row_width * 2;
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = lo_filler;
+ *(--dp) = hi_filler;
+ }
+
+ row_info->channels = 4;
+ row_info->pixel_depth = 64;
+ row_info->rowbytes = row_width * 8;
+ }
+ }
+#endif
+ } /* COLOR_TYPE == RGB */
+}
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+/* Expand grayscale files to RGB, with or without alpha */
+static void
+png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
+{
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ png_debug(1, "in png_do_gray_to_rgb");
+
+ if (row_info->bit_depth >= 8 &&
+ (row_info->color_type & PNG_COLOR_MASK_COLOR) == 0)
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ /* This changes G to RGB */
+ png_bytep sp = row + (size_t)row_width - 1;
+ png_bytep dp = sp + (size_t)row_width * 2;
+ for (i = 0; i < row_width; i++)
+ {
+ *(dp--) = *sp;
+ *(dp--) = *sp;
+ *(dp--) = *(sp--);
+ }
+ }
+
+ else
+ {
+ /* This changes GG to RRGGBB */
+ png_bytep sp = row + (size_t)row_width * 2 - 1;
+ png_bytep dp = sp + (size_t)row_width * 4;
+ for (i = 0; i < row_width; i++)
+ {
+ *(dp--) = *sp;
+ *(dp--) = *(sp - 1);
+ *(dp--) = *sp;
+ *(dp--) = *(sp - 1);
+ *(dp--) = *(sp--);
+ *(dp--) = *(sp--);
+ }
+ }
+ }
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ /* This changes GA to RGBA */
+ png_bytep sp = row + (size_t)row_width * 2 - 1;
+ png_bytep dp = sp + (size_t)row_width * 2;
+ for (i = 0; i < row_width; i++)
+ {
+ *(dp--) = *(sp--);
+ *(dp--) = *sp;
+ *(dp--) = *sp;
+ *(dp--) = *(sp--);
+ }
+ }
+
+ else
+ {
+ /* This changes GGAA to RRGGBBAA */
+ png_bytep sp = row + (size_t)row_width * 4 - 1;
+ png_bytep dp = sp + (size_t)row_width * 4;
+ for (i = 0; i < row_width; i++)
+ {
+ *(dp--) = *(sp--);
+ *(dp--) = *(sp--);
+ *(dp--) = *sp;
+ *(dp--) = *(sp - 1);
+ *(dp--) = *sp;
+ *(dp--) = *(sp - 1);
+ *(dp--) = *(sp--);
+ *(dp--) = *(sp--);
+ }
+ }
+ }
+ row_info->channels = (png_byte)(row_info->channels + 2);
+ row_info->color_type |= PNG_COLOR_MASK_COLOR;
+ row_info->pixel_depth = (png_byte)(row_info->channels *
+ row_info->bit_depth);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+ }
+}
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+/* Reduce RGB files to grayscale, with or without alpha
+ * using the equation given in Poynton's ColorFAQ of 1998-01-04 at
+ * (THIS LINK IS DEAD June 2008 but
+ * versions dated 1998 through November 2002 have been archived at
+ * https://web.archive.org/web/20000816232553/www.inforamp.net/
+ * ~poynton/notes/colour_and_gamma/ColorFAQ.txt )
+ * Charles Poynton poynton at poynton.com
+ *
+ * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
+ *
+ * which can be expressed with integers as
+ *
+ * Y = (6969 * R + 23434 * G + 2365 * B)/32768
+ *
+ * Poynton's current link (as of January 2003 through July 2011):
+ *
+ * has changed the numbers slightly:
+ *
+ * Y = 0.2126*R + 0.7152*G + 0.0722*B
+ *
+ * which can be expressed with integers as
+ *
+ * Y = (6966 * R + 23436 * G + 2366 * B)/32768
+ *
+ * Historically, however, libpng uses numbers derived from the ITU-R Rec 709
+ * end point chromaticities and the D65 white point. Depending on the
+ * precision used for the D65 white point this produces a variety of different
+ * numbers, however if the four decimal place value used in ITU-R Rec 709 is
+ * used (0.3127,0.3290) the Y calculation would be:
+ *
+ * Y = (6968 * R + 23435 * G + 2366 * B)/32768
+ *
+ * While this is correct the rounding results in an overflow for white, because
+ * the sum of the rounded coefficients is 32769, not 32768. Consequently
+ * libpng uses, instead, the closest non-overflowing approximation:
+ *
+ * Y = (6968 * R + 23434 * G + 2366 * B)/32768
+ *
+ * Starting with libpng-1.5.5, if the image being converted has a cHRM chunk
+ * (including an sRGB chunk) then the chromaticities are used to calculate the
+ * coefficients. See the chunk handling in pngrutil.c for more information.
+ *
+ * In all cases the calculation is to be done in a linear colorspace. If no
+ * gamma information is available to correct the encoding of the original RGB
+ * values this results in an implicit assumption that the original PNG RGB
+ * values were linear.
+ *
+ * Other integer coefficients can be used via png_set_rgb_to_gray(). Because
+ * the API takes just red and green coefficients the blue coefficient is
+ * calculated to make the sum 32768. This will result in different rounding
+ * to that used above.
+ */
+static int
+png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row)
+{
+ int rgb_error = 0;
+
+ png_debug(1, "in png_do_rgb_to_gray");
+
+ if ((row_info->color_type & PNG_COLOR_MASK_PALETTE) == 0 &&
+ (row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ {
+ png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff;
+ png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff;
+ png_uint_32 bc = 32768 - rc - gc;
+ png_uint_32 row_width = row_info->width;
+ int have_alpha = (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0;
+
+ if (row_info->bit_depth == 8)
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ /* Notice that gamma to/from 1 are not necessarily inverses (if
+ * there is an overall gamma correction). Prior to 1.5.5 this code
+ * checked the linearized values for equality; this doesn't match
+ * the documentation, the original values must be checked.
+ */
+ if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ png_byte red = *(sp++);
+ png_byte green = *(sp++);
+ png_byte blue = *(sp++);
+
+ if (red != green || red != blue)
+ {
+ red = png_ptr->gamma_to_1[red];
+ green = png_ptr->gamma_to_1[green];
+ blue = png_ptr->gamma_to_1[blue];
+
+ rgb_error |= 1;
+ *(dp++) = png_ptr->gamma_from_1[
+ (rc*red + gc*green + bc*blue + 16384)>>15];
+ }
+
+ else
+ {
+ /* If there is no overall correction the table will not be
+ * set.
+ */
+ if (png_ptr->gamma_table != NULL)
+ red = png_ptr->gamma_table[red];
+
+ *(dp++) = red;
+ }
+
+ if (have_alpha != 0)
+ *(dp++) = *(sp++);
+ }
+ }
+ else
+#endif
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ png_byte red = *(sp++);
+ png_byte green = *(sp++);
+ png_byte blue = *(sp++);
+
+ if (red != green || red != blue)
+ {
+ rgb_error |= 1;
+ /* NOTE: this is the historical approach which simply
+ * truncates the results.
+ */
+ *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15);
+ }
+
+ else
+ *(dp++) = red;
+
+ if (have_alpha != 0)
+ *(dp++) = *(sp++);
+ }
+ }
+ }
+
+ else /* RGB bit_depth == 16 */
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (png_ptr->gamma_16_to_1 != NULL && png_ptr->gamma_16_from_1 != NULL)
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 red, green, blue, w;
+ png_byte hi,lo;
+
+ hi=*(sp)++; lo=*(sp)++; red = (png_uint_16)((hi << 8) | (lo));
+ hi=*(sp)++; lo=*(sp)++; green = (png_uint_16)((hi << 8) | (lo));
+ hi=*(sp)++; lo=*(sp)++; blue = (png_uint_16)((hi << 8) | (lo));
+
+ if (red == green && red == blue)
+ {
+ if (png_ptr->gamma_16_table != NULL)
+ w = png_ptr->gamma_16_table[(red & 0xff)
+ >> png_ptr->gamma_shift][red >> 8];
+
+ else
+ w = red;
+ }
+
+ else
+ {
+ png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red & 0xff)
+ >> png_ptr->gamma_shift][red>>8];
+ png_uint_16 green_1 =
+ png_ptr->gamma_16_to_1[(green & 0xff) >>
+ png_ptr->gamma_shift][green>>8];
+ png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue & 0xff)
+ >> png_ptr->gamma_shift][blue>>8];
+ png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1
+ + bc*blue_1 + 16384)>>15);
+ w = png_ptr->gamma_16_from_1[(gray16 & 0xff) >>
+ png_ptr->gamma_shift][gray16 >> 8];
+ rgb_error |= 1;
+ }
+
+ *(dp++) = (png_byte)((w>>8) & 0xff);
+ *(dp++) = (png_byte)(w & 0xff);
+
+ if (have_alpha != 0)
+ {
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ }
+ }
+ }
+ else
+#endif
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 red, green, blue, gray16;
+ png_byte hi,lo;
+
+ hi=*(sp)++; lo=*(sp)++; red = (png_uint_16)((hi << 8) | (lo));
+ hi=*(sp)++; lo=*(sp)++; green = (png_uint_16)((hi << 8) | (lo));
+ hi=*(sp)++; lo=*(sp)++; blue = (png_uint_16)((hi << 8) | (lo));
+
+ if (red != green || red != blue)
+ rgb_error |= 1;
+
+ /* From 1.5.5 in the 16-bit case do the accurate conversion even
+ * in the 'fast' case - this is because this is where the code
+ * ends up when handling linear 16-bit data.
+ */
+ gray16 = (png_uint_16)((rc*red + gc*green + bc*blue + 16384) >>
+ 15);
+ *(dp++) = (png_byte)((gray16 >> 8) & 0xff);
+ *(dp++) = (png_byte)(gray16 & 0xff);
+
+ if (have_alpha != 0)
+ {
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ }
+ }
+ }
+ }
+
+ row_info->channels = (png_byte)(row_info->channels - 2);
+ row_info->color_type = (png_byte)(row_info->color_type &
+ ~PNG_COLOR_MASK_COLOR);
+ row_info->pixel_depth = (png_byte)(row_info->channels *
+ row_info->bit_depth);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+ }
+ return rgb_error;
+}
+#endif
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+ defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+/* Replace any alpha or transparency with the supplied background color.
+ * "background" is already in the screen gamma, while "background_1" is
+ * at a gamma of 1.0. Paletted files have already been taken care of.
+ */
+static void
+png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
+{
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ png_const_bytep gamma_table = png_ptr->gamma_table;
+ png_const_bytep gamma_from_1 = png_ptr->gamma_from_1;
+ png_const_bytep gamma_to_1 = png_ptr->gamma_to_1;
+ png_const_uint_16pp gamma_16 = png_ptr->gamma_16_table;
+ png_const_uint_16pp gamma_16_from_1 = png_ptr->gamma_16_from_1;
+ png_const_uint_16pp gamma_16_to_1 = png_ptr->gamma_16_to_1;
+ int gamma_shift = png_ptr->gamma_shift;
+ int optimize = (png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0;
+#endif
+
+ png_bytep sp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+ int shift;
+
+ png_debug(1, "in png_do_compose");
+
+ switch (row_info->color_type)
+ {
+ case PNG_COLOR_TYPE_GRAY:
+ {
+ switch (row_info->bit_depth)
+ {
+ case 1:
+ {
+ sp = row;
+ shift = 7;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((png_uint_16)((*sp >> shift) & 0x01)
+ == png_ptr->trans_color.gray)
+ {
+ unsigned int tmp = *sp & (0x7f7f >> (7 - shift));
+ tmp |=
+ (unsigned int)(png_ptr->background.gray << shift);
+ *sp = (png_byte)(tmp & 0xff);
+ }
+
+ if (shift == 0)
+ {
+ shift = 7;
+ sp++;
+ }
+
+ else
+ shift--;
+ }
+ break;
+ }
+
+ case 2:
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_table != NULL)
+ {
+ sp = row;
+ shift = 6;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((png_uint_16)((*sp >> shift) & 0x03)
+ == png_ptr->trans_color.gray)
+ {
+ unsigned int tmp = *sp & (0x3f3f >> (6 - shift));
+ tmp |=
+ (unsigned int)png_ptr->background.gray << shift;
+ *sp = (png_byte)(tmp & 0xff);
+ }
+
+ else
+ {
+ unsigned int p = (*sp >> shift) & 0x03;
+ unsigned int g = (gamma_table [p | (p << 2) |
+ (p << 4) | (p << 6)] >> 6) & 0x03;
+ unsigned int tmp = *sp & (0x3f3f >> (6 - shift));
+ tmp |= (unsigned int)(g << shift);
+ *sp = (png_byte)(tmp & 0xff);
+ }
+
+ if (shift == 0)
+ {
+ shift = 6;
+ sp++;
+ }
+
+ else
+ shift -= 2;
+ }
+ }
+
+ else
+#endif
+ {
+ sp = row;
+ shift = 6;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((png_uint_16)((*sp >> shift) & 0x03)
+ == png_ptr->trans_color.gray)
+ {
+ unsigned int tmp = *sp & (0x3f3f >> (6 - shift));
+ tmp |=
+ (unsigned int)png_ptr->background.gray << shift;
+ *sp = (png_byte)(tmp & 0xff);
+ }
+
+ if (shift == 0)
+ {
+ shift = 6;
+ sp++;
+ }
+
+ else
+ shift -= 2;
+ }
+ }
+ break;
+ }
+
+ case 4:
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_table != NULL)
+ {
+ sp = row;
+ shift = 4;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((png_uint_16)((*sp >> shift) & 0x0f)
+ == png_ptr->trans_color.gray)
+ {
+ unsigned int tmp = *sp & (0x0f0f >> (4 - shift));
+ tmp |=
+ (unsigned int)(png_ptr->background.gray << shift);
+ *sp = (png_byte)(tmp & 0xff);
+ }
+
+ else
+ {
+ unsigned int p = (*sp >> shift) & 0x0f;
+ unsigned int g = (gamma_table[p | (p << 4)] >> 4) &
+ 0x0f;
+ unsigned int tmp = *sp & (0x0f0f >> (4 - shift));
+ tmp |= (unsigned int)(g << shift);
+ *sp = (png_byte)(tmp & 0xff);
+ }
+
+ if (shift == 0)
+ {
+ shift = 4;
+ sp++;
+ }
+
+ else
+ shift -= 4;
+ }
+ }
+
+ else
+#endif
+ {
+ sp = row;
+ shift = 4;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((png_uint_16)((*sp >> shift) & 0x0f)
+ == png_ptr->trans_color.gray)
+ {
+ unsigned int tmp = *sp & (0x0f0f >> (4 - shift));
+ tmp |=
+ (unsigned int)(png_ptr->background.gray << shift);
+ *sp = (png_byte)(tmp & 0xff);
+ }
+
+ if (shift == 0)
+ {
+ shift = 4;
+ sp++;
+ }
+
+ else
+ shift -= 4;
+ }
+ }
+ break;
+ }
+
+ case 8:
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_table != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp++)
+ {
+ if (*sp == png_ptr->trans_color.gray)
+ *sp = (png_byte)png_ptr->background.gray;
+
+ else
+ *sp = gamma_table[*sp];
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp++)
+ {
+ if (*sp == png_ptr->trans_color.gray)
+ *sp = (png_byte)png_ptr->background.gray;
+ }
+ }
+ break;
+ }
+
+ case 16:
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_16 != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 2)
+ {
+ png_uint_16 v;
+
+ v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+
+ if (v == png_ptr->trans_color.gray)
+ {
+ /* Background is already in screen gamma */
+ *sp = (png_byte)((png_ptr->background.gray >> 8)
+ & 0xff);
+ *(sp + 1) = (png_byte)(png_ptr->background.gray
+ & 0xff);
+ }
+
+ else
+ {
+ v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 2)
+ {
+ png_uint_16 v;
+
+ v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+
+ if (v == png_ptr->trans_color.gray)
+ {
+ *sp = (png_byte)((png_ptr->background.gray >> 8)
+ & 0xff);
+ *(sp + 1) = (png_byte)(png_ptr->background.gray
+ & 0xff);
+ }
+ }
+ }
+ break;
+ }
+
+ default:
+ break;
+ }
+ break;
+ }
+
+ case PNG_COLOR_TYPE_RGB:
+ {
+ if (row_info->bit_depth == 8)
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_table != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 3)
+ {
+ if (*sp == png_ptr->trans_color.red &&
+ *(sp + 1) == png_ptr->trans_color.green &&
+ *(sp + 2) == png_ptr->trans_color.blue)
+ {
+ *sp = (png_byte)png_ptr->background.red;
+ *(sp + 1) = (png_byte)png_ptr->background.green;
+ *(sp + 2) = (png_byte)png_ptr->background.blue;
+ }
+
+ else
+ {
+ *sp = gamma_table[*sp];
+ *(sp + 1) = gamma_table[*(sp + 1)];
+ *(sp + 2) = gamma_table[*(sp + 2)];
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 3)
+ {
+ if (*sp == png_ptr->trans_color.red &&
+ *(sp + 1) == png_ptr->trans_color.green &&
+ *(sp + 2) == png_ptr->trans_color.blue)
+ {
+ *sp = (png_byte)png_ptr->background.red;
+ *(sp + 1) = (png_byte)png_ptr->background.green;
+ *(sp + 2) = (png_byte)png_ptr->background.blue;
+ }
+ }
+ }
+ }
+ else /* if (row_info->bit_depth == 16) */
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_16 != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 6)
+ {
+ png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+
+ png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
+ + *(sp + 3));
+
+ png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
+ + *(sp + 5));
+
+ if (r == png_ptr->trans_color.red &&
+ g == png_ptr->trans_color.green &&
+ b == png_ptr->trans_color.blue)
+ {
+ /* Background is already in screen gamma */
+ *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
+ *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
+ & 0xff);
+ *(sp + 3) = (png_byte)(png_ptr->background.green
+ & 0xff);
+ *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
+ & 0xff);
+ *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
+ }
+
+ else
+ {
+ png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+
+ v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
+ *(sp + 2) = (png_byte)((v >> 8) & 0xff);
+ *(sp + 3) = (png_byte)(v & 0xff);
+
+ v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
+ *(sp + 4) = (png_byte)((v >> 8) & 0xff);
+ *(sp + 5) = (png_byte)(v & 0xff);
+ }
+ }
+ }
+
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 6)
+ {
+ png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+
+ png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
+ + *(sp + 3));
+
+ png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
+ + *(sp + 5));
+
+ if (r == png_ptr->trans_color.red &&
+ g == png_ptr->trans_color.green &&
+ b == png_ptr->trans_color.blue)
+ {
+ *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
+ *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
+ & 0xff);
+ *(sp + 3) = (png_byte)(png_ptr->background.green
+ & 0xff);
+ *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
+ & 0xff);
+ *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
+ }
+ }
+ }
+ }
+ break;
+ }
+
+ case PNG_COLOR_TYPE_GRAY_ALPHA:
+ {
+ if (row_info->bit_depth == 8)
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
+ gamma_table != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 2)
+ {
+ png_uint_16 a = *(sp + 1);
+
+ if (a == 0xff)
+ *sp = gamma_table[*sp];
+
+ else if (a == 0)
+ {
+ /* Background is already in screen gamma */
+ *sp = (png_byte)png_ptr->background.gray;
+ }
+
+ else
+ {
+ png_byte v, w;
+
+ v = gamma_to_1[*sp];
+ png_composite(w, v, a, png_ptr->background_1.gray);
+ if (optimize == 0)
+ w = gamma_from_1[w];
+ *sp = w;
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 2)
+ {
+ png_byte a = *(sp + 1);
+
+ if (a == 0)
+ *sp = (png_byte)png_ptr->background.gray;
+
+ else if (a < 0xff)
+ png_composite(*sp, *sp, a, png_ptr->background.gray);
+ }
+ }
+ }
+ else /* if (png_ptr->bit_depth == 16) */
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
+ gamma_16_to_1 != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 4)
+ {
+ png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8)
+ + *(sp + 3));
+
+ if (a == (png_uint_16)0xffff)
+ {
+ png_uint_16 v;
+
+ v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ }
+
+ else if (a == 0)
+ {
+ /* Background is already in screen gamma */
+ *sp = (png_byte)((png_ptr->background.gray >> 8)
+ & 0xff);
+ *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
+ }
+
+ else
+ {
+ png_uint_16 g, v, w;
+
+ g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
+ png_composite_16(v, g, a, png_ptr->background_1.gray);
+ if (optimize != 0)
+ w = v;
+ else
+ w = gamma_16_from_1[(v & 0xff) >>
+ gamma_shift][v >> 8];
+ *sp = (png_byte)((w >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(w & 0xff);
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 4)
+ {
+ png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8)
+ + *(sp + 3));
+
+ if (a == 0)
+ {
+ *sp = (png_byte)((png_ptr->background.gray >> 8)
+ & 0xff);
+ *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
+ }
+
+ else if (a < 0xffff)
+ {
+ png_uint_16 g, v;
+
+ g = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+ png_composite_16(v, g, a, png_ptr->background.gray);
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ }
+ }
+ }
+ }
+ break;
+ }
+
+ case PNG_COLOR_TYPE_RGB_ALPHA:
+ {
+ if (row_info->bit_depth == 8)
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
+ gamma_table != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 4)
+ {
+ png_byte a = *(sp + 3);
+
+ if (a == 0xff)
+ {
+ *sp = gamma_table[*sp];
+ *(sp + 1) = gamma_table[*(sp + 1)];
+ *(sp + 2) = gamma_table[*(sp + 2)];
+ }
+
+ else if (a == 0)
+ {
+ /* Background is already in screen gamma */
+ *sp = (png_byte)png_ptr->background.red;
+ *(sp + 1) = (png_byte)png_ptr->background.green;
+ *(sp + 2) = (png_byte)png_ptr->background.blue;
+ }
+
+ else
+ {
+ png_byte v, w;
+
+ v = gamma_to_1[*sp];
+ png_composite(w, v, a, png_ptr->background_1.red);
+ if (optimize == 0) w = gamma_from_1[w];
+ *sp = w;
+
+ v = gamma_to_1[*(sp + 1)];
+ png_composite(w, v, a, png_ptr->background_1.green);
+ if (optimize == 0) w = gamma_from_1[w];
+ *(sp + 1) = w;
+
+ v = gamma_to_1[*(sp + 2)];
+ png_composite(w, v, a, png_ptr->background_1.blue);
+ if (optimize == 0) w = gamma_from_1[w];
+ *(sp + 2) = w;
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 4)
+ {
+ png_byte a = *(sp + 3);
+
+ if (a == 0)
+ {
+ *sp = (png_byte)png_ptr->background.red;
+ *(sp + 1) = (png_byte)png_ptr->background.green;
+ *(sp + 2) = (png_byte)png_ptr->background.blue;
+ }
+
+ else if (a < 0xff)
+ {
+ png_composite(*sp, *sp, a, png_ptr->background.red);
+
+ png_composite(*(sp + 1), *(sp + 1), a,
+ png_ptr->background.green);
+
+ png_composite(*(sp + 2), *(sp + 2), a,
+ png_ptr->background.blue);
+ }
+ }
+ }
+ }
+ else /* if (row_info->bit_depth == 16) */
+ {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
+ gamma_16_to_1 != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 8)
+ {
+ png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
+ << 8) + (png_uint_16)(*(sp + 7)));
+
+ if (a == (png_uint_16)0xffff)
+ {
+ png_uint_16 v;
+
+ v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+
+ v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
+ *(sp + 2) = (png_byte)((v >> 8) & 0xff);
+ *(sp + 3) = (png_byte)(v & 0xff);
+
+ v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
+ *(sp + 4) = (png_byte)((v >> 8) & 0xff);
+ *(sp + 5) = (png_byte)(v & 0xff);
+ }
+
+ else if (a == 0)
+ {
+ /* Background is already in screen gamma */
+ *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
+ *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
+ & 0xff);
+ *(sp + 3) = (png_byte)(png_ptr->background.green
+ & 0xff);
+ *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
+ & 0xff);
+ *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
+ }
+
+ else
+ {
+ png_uint_16 v, w;
+
+ v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
+ png_composite_16(w, v, a, png_ptr->background_1.red);
+ if (optimize == 0)
+ w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >>
+ 8];
+ *sp = (png_byte)((w >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(w & 0xff);
+
+ v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)];
+ png_composite_16(w, v, a, png_ptr->background_1.green);
+ if (optimize == 0)
+ w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >>
+ 8];
+
+ *(sp + 2) = (png_byte)((w >> 8) & 0xff);
+ *(sp + 3) = (png_byte)(w & 0xff);
+
+ v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)];
+ png_composite_16(w, v, a, png_ptr->background_1.blue);
+ if (optimize == 0)
+ w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >>
+ 8];
+
+ *(sp + 4) = (png_byte)((w >> 8) & 0xff);
+ *(sp + 5) = (png_byte)(w & 0xff);
+ }
+ }
+ }
+
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 8)
+ {
+ png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
+ << 8) + (png_uint_16)(*(sp + 7)));
+
+ if (a == 0)
+ {
+ *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
+ *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
+ & 0xff);
+ *(sp + 3) = (png_byte)(png_ptr->background.green
+ & 0xff);
+ *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
+ & 0xff);
+ *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
+ }
+
+ else if (a < 0xffff)
+ {
+ png_uint_16 v;
+
+ png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+ png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
+ + *(sp + 3));
+ png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
+ + *(sp + 5));
+
+ png_composite_16(v, r, a, png_ptr->background.red);
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+
+ png_composite_16(v, g, a, png_ptr->background.green);
+ *(sp + 2) = (png_byte)((v >> 8) & 0xff);
+ *(sp + 3) = (png_byte)(v & 0xff);
+
+ png_composite_16(v, b, a, png_ptr->background.blue);
+ *(sp + 4) = (png_byte)((v >> 8) & 0xff);
+ *(sp + 5) = (png_byte)(v & 0xff);
+ }
+ }
+ }
+ }
+ break;
+ }
+
+ default:
+ break;
+ }
+}
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE */
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* Gamma correct the image, avoiding the alpha channel. Make sure
+ * you do this after you deal with the transparency issue on grayscale
+ * or RGB images. If your bit depth is 8, use gamma_table, if it
+ * is 16, use gamma_16_table and gamma_shift. Build these with
+ * build_gamma_table().
+ */
+static void
+png_do_gamma(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
+{
+ png_const_bytep gamma_table = png_ptr->gamma_table;
+ png_const_uint_16pp gamma_16_table = png_ptr->gamma_16_table;
+ int gamma_shift = png_ptr->gamma_shift;
+
+ png_bytep sp;
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+
+ png_debug(1, "in png_do_gamma");
+
+ if (((row_info->bit_depth <= 8 && gamma_table != NULL) ||
+ (row_info->bit_depth == 16 && gamma_16_table != NULL)))
+ {
+ switch (row_info->color_type)
+ {
+ case PNG_COLOR_TYPE_RGB:
+ {
+ if (row_info->bit_depth == 8)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ *sp = gamma_table[*sp];
+ sp++;
+ *sp = gamma_table[*sp];
+ sp++;
+ *sp = gamma_table[*sp];
+ sp++;
+ }
+ }
+
+ else /* if (row_info->bit_depth == 16) */
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 v;
+
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+ }
+ }
+ break;
+ }
+
+ case PNG_COLOR_TYPE_RGB_ALPHA:
+ {
+ if (row_info->bit_depth == 8)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ *sp = gamma_table[*sp];
+ sp++;
+
+ *sp = gamma_table[*sp];
+ sp++;
+
+ *sp = gamma_table[*sp];
+ sp++;
+
+ sp++;
+ }
+ }
+
+ else /* if (row_info->bit_depth == 16) */
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 4;
+ }
+ }
+ break;
+ }
+
+ case PNG_COLOR_TYPE_GRAY_ALPHA:
+ {
+ if (row_info->bit_depth == 8)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ *sp = gamma_table[*sp];
+ sp += 2;
+ }
+ }
+
+ else /* if (row_info->bit_depth == 16) */
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 4;
+ }
+ }
+ break;
+ }
+
+ case PNG_COLOR_TYPE_GRAY:
+ {
+ if (row_info->bit_depth == 2)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i += 4)
+ {
+ int a = *sp & 0xc0;
+ int b = *sp & 0x30;
+ int c = *sp & 0x0c;
+ int d = *sp & 0x03;
+
+ *sp = (png_byte)(
+ ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)|
+ ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)|
+ ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)|
+ ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) ));
+ sp++;
+ }
+ }
+
+ if (row_info->bit_depth == 4)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i += 2)
+ {
+ int msb = *sp & 0xf0;
+ int lsb = *sp & 0x0f;
+
+ *sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0)
+ | (((int)gamma_table[(lsb << 4) | lsb]) >> 4));
+ sp++;
+ }
+ }
+
+ else if (row_info->bit_depth == 8)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ *sp = gamma_table[*sp];
+ sp++;
+ }
+ }
+
+ else if (row_info->bit_depth == 16)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+ }
+ }
+ break;
+ }
+
+ default:
+ break;
+ }
+ }
+}
+#endif
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+/* Encode the alpha channel to the output gamma (the input channel is always
+ * linear.) Called only with color types that have an alpha channel. Needs the
+ * from_1 tables.
+ */
+static void
+png_do_encode_alpha(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
+{
+ png_uint_32 row_width = row_info->width;
+
+ png_debug(1, "in png_do_encode_alpha");
+
+ if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep table = png_ptr->gamma_from_1;
+
+ if (table != NULL)
+ {
+ int step = (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 4 : 2;
+
+ /* The alpha channel is the last component: */
+ row += step - 1;
+
+ for (; row_width > 0; --row_width, row += step)
+ *row = table[*row];
+
+ return;
+ }
+ }
+
+ else if (row_info->bit_depth == 16)
+ {
+ png_uint_16pp table = png_ptr->gamma_16_from_1;
+ int gamma_shift = png_ptr->gamma_shift;
+
+ if (table != NULL)
+ {
+ int step = (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 8 : 4;
+
+ /* The alpha channel is the last component: */
+ row += step - 2;
+
+ for (; row_width > 0; --row_width, row += step)
+ {
+ png_uint_16 v;
+
+ v = table[*(row + 1) >> gamma_shift][*row];
+ *row = (png_byte)((v >> 8) & 0xff);
+ *(row + 1) = (png_byte)(v & 0xff);
+ }
+
+ return;
+ }
+ }
+ }
+
+ /* Only get to here if called with a weird row_info; no harm has been done,
+ * so just issue a warning.
+ */
+ png_warning(png_ptr, "png_do_encode_alpha: unexpected call");
+}
+#endif
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+/* Expands a palette row to an RGB or RGBA row depending
+ * upon whether you supply trans and num_trans.
+ */
+static void
+png_do_expand_palette(png_structrp png_ptr, png_row_infop row_info,
+ png_bytep row, png_const_colorp palette, png_const_bytep trans_alpha,
+ int num_trans)
+{
+ int shift, value;
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+
+ png_debug(1, "in png_do_expand_palette");
+
+ if (row_info->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (row_info->bit_depth < 8)
+ {
+ switch (row_info->bit_depth)
+ {
+ case 1:
+ {
+ sp = row + (size_t)((row_width - 1) >> 3);
+ dp = row + (size_t)row_width - 1;
+ shift = 7 - (int)((row_width + 7) & 0x07);
+ for (i = 0; i < row_width; i++)
+ {
+ if ((*sp >> shift) & 0x01)
+ *dp = 1;
+
+ else
+ *dp = 0;
+
+ if (shift == 7)
+ {
+ shift = 0;
+ sp--;
+ }
+
+ else
+ shift++;
+
+ dp--;
+ }
+ break;
+ }
+
+ case 2:
+ {
+ sp = row + (size_t)((row_width - 1) >> 2);
+ dp = row + (size_t)row_width - 1;
+ shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
+ for (i = 0; i < row_width; i++)
+ {
+ value = (*sp >> shift) & 0x03;
+ *dp = (png_byte)value;
+ if (shift == 6)
+ {
+ shift = 0;
+ sp--;
+ }
+
+ else
+ shift += 2;
+
+ dp--;
+ }
+ break;
+ }
+
+ case 4:
+ {
+ sp = row + (size_t)((row_width - 1) >> 1);
+ dp = row + (size_t)row_width - 1;
+ shift = (int)((row_width & 0x01) << 2);
+ for (i = 0; i < row_width; i++)
+ {
+ value = (*sp >> shift) & 0x0f;
+ *dp = (png_byte)value;
+ if (shift == 4)
+ {
+ shift = 0;
+ sp--;
+ }
+
+ else
+ shift += 4;
+
+ dp--;
+ }
+ break;
+ }
+
+ default:
+ break;
+ }
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = 8;
+ row_info->rowbytes = row_width;
+ }
+
+ if (row_info->bit_depth == 8)
+ {
+ {
+ if (num_trans > 0)
+ {
+ sp = row + (size_t)row_width - 1;
+ dp = row + ((size_t)row_width << 2) - 1;
+
+ i = 0;
+#ifdef PNG_ARM_NEON_INTRINSICS_AVAILABLE
+ if (png_ptr->riffled_palette != NULL)
+ {
+ /* The RGBA optimization works with png_ptr->bit_depth == 8
+ * but sometimes row_info->bit_depth has been changed to 8.
+ * In these cases, the palette hasn't been riffled.
+ */
+ i = png_do_expand_palette_rgba8_neon(png_ptr, row_info, row,
+ &sp, &dp);
+ }
+#else
+ PNG_UNUSED(png_ptr)
+#endif
+
+ for (; i < row_width; i++)
+ {
+ if ((int)(*sp) >= num_trans)
+ *dp-- = 0xff;
+ else
+ *dp-- = trans_alpha[*sp];
+ *dp-- = palette[*sp].blue;
+ *dp-- = palette[*sp].green;
+ *dp-- = palette[*sp].red;
+ sp--;
+ }
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = 32;
+ row_info->rowbytes = row_width * 4;
+ row_info->color_type = 6;
+ row_info->channels = 4;
+ }
+
+ else
+ {
+ sp = row + (size_t)row_width - 1;
+ dp = row + (size_t)(row_width * 3) - 1;
+ i = 0;
+#ifdef PNG_ARM_NEON_INTRINSICS_AVAILABLE
+ i = png_do_expand_palette_rgb8_neon(png_ptr, row_info, row,
+ &sp, &dp);
+#else
+ PNG_UNUSED(png_ptr)
+#endif
+
+ for (; i < row_width; i++)
+ {
+ *dp-- = palette[*sp].blue;
+ *dp-- = palette[*sp].green;
+ *dp-- = palette[*sp].red;
+ sp--;
+ }
+
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = 24;
+ row_info->rowbytes = row_width * 3;
+ row_info->color_type = 2;
+ row_info->channels = 3;
+ }
+ }
+ }
+ }
+}
+
+/* If the bit depth < 8, it is expanded to 8. Also, if the already
+ * expanded transparency value is supplied, an alpha channel is built.
+ */
+static void
+png_do_expand(png_row_infop row_info, png_bytep row,
+ png_const_color_16p trans_color)
+{
+ int shift, value;
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+
+ png_debug(1, "in png_do_expand");
+
+ if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ unsigned int gray = trans_color != NULL ? trans_color->gray : 0;
+
+ if (row_info->bit_depth < 8)
+ {
+ switch (row_info->bit_depth)
+ {
+ case 1:
+ {
+ gray = (gray & 0x01) * 0xff;
+ sp = row + (size_t)((row_width - 1) >> 3);
+ dp = row + (size_t)row_width - 1;
+ shift = 7 - (int)((row_width + 7) & 0x07);
+ for (i = 0; i < row_width; i++)
+ {
+ if ((*sp >> shift) & 0x01)
+ *dp = 0xff;
+
+ else
+ *dp = 0;
+
+ if (shift == 7)
+ {
+ shift = 0;
+ sp--;
+ }
+
+ else
+ shift++;
+
+ dp--;
+ }
+ break;
+ }
+
+ case 2:
+ {
+ gray = (gray & 0x03) * 0x55;
+ sp = row + (size_t)((row_width - 1) >> 2);
+ dp = row + (size_t)row_width - 1;
+ shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
+ for (i = 0; i < row_width; i++)
+ {
+ value = (*sp >> shift) & 0x03;
+ *dp = (png_byte)(value | (value << 2) | (value << 4) |
+ (value << 6));
+ if (shift == 6)
+ {
+ shift = 0;
+ sp--;
+ }
+
+ else
+ shift += 2;
+
+ dp--;
+ }
+ break;
+ }
+
+ case 4:
+ {
+ gray = (gray & 0x0f) * 0x11;
+ sp = row + (size_t)((row_width - 1) >> 1);
+ dp = row + (size_t)row_width - 1;
+ shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
+ for (i = 0; i < row_width; i++)
+ {
+ value = (*sp >> shift) & 0x0f;
+ *dp = (png_byte)(value | (value << 4));
+ if (shift == 4)
+ {
+ shift = 0;
+ sp--;
+ }
+
+ else
+ shift = 4;
+
+ dp--;
+ }
+ break;
+ }
+
+ default:
+ break;
+ }
+
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = 8;
+ row_info->rowbytes = row_width;
+ }
+
+ if (trans_color != NULL)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ gray = gray & 0xff;
+ sp = row + (size_t)row_width - 1;
+ dp = row + ((size_t)row_width << 1) - 1;
+
+ for (i = 0; i < row_width; i++)
+ {
+ if ((*sp & 0xffU) == gray)
+ *dp-- = 0;
+
+ else
+ *dp-- = 0xff;
+
+ *dp-- = *sp--;
+ }
+ }
+
+ else if (row_info->bit_depth == 16)
+ {
+ unsigned int gray_high = (gray >> 8) & 0xff;
+ unsigned int gray_low = gray & 0xff;
+ sp = row + row_info->rowbytes - 1;
+ dp = row + (row_info->rowbytes << 1) - 1;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((*(sp - 1) & 0xffU) == gray_high &&
+ (*(sp) & 0xffU) == gray_low)
+ {
+ *dp-- = 0;
+ *dp-- = 0;
+ }
+
+ else
+ {
+ *dp-- = 0xff;
+ *dp-- = 0xff;
+ }
+
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ }
+ }
+
+ row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
+ row_info->channels = 2;
+ row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
+ row_width);
+ }
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB &&
+ trans_color != NULL)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ png_byte red = (png_byte)(trans_color->red & 0xff);
+ png_byte green = (png_byte)(trans_color->green & 0xff);
+ png_byte blue = (png_byte)(trans_color->blue & 0xff);
+ sp = row + (size_t)row_info->rowbytes - 1;
+ dp = row + ((size_t)row_width << 2) - 1;
+ for (i = 0; i < row_width; i++)
+ {
+ if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue)
+ *dp-- = 0;
+
+ else
+ *dp-- = 0xff;
+
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ }
+ }
+ else if (row_info->bit_depth == 16)
+ {
+ png_byte red_high = (png_byte)((trans_color->red >> 8) & 0xff);
+ png_byte green_high = (png_byte)((trans_color->green >> 8) & 0xff);
+ png_byte blue_high = (png_byte)((trans_color->blue >> 8) & 0xff);
+ png_byte red_low = (png_byte)(trans_color->red & 0xff);
+ png_byte green_low = (png_byte)(trans_color->green & 0xff);
+ png_byte blue_low = (png_byte)(trans_color->blue & 0xff);
+ sp = row + row_info->rowbytes - 1;
+ dp = row + ((size_t)row_width << 3) - 1;
+ for (i = 0; i < row_width; i++)
+ {
+ if (*(sp - 5) == red_high &&
+ *(sp - 4) == red_low &&
+ *(sp - 3) == green_high &&
+ *(sp - 2) == green_low &&
+ *(sp - 1) == blue_high &&
+ *(sp ) == blue_low)
+ {
+ *dp-- = 0;
+ *dp-- = 0;
+ }
+
+ else
+ {
+ *dp-- = 0xff;
+ *dp-- = 0xff;
+ }
+
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ }
+ }
+ row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+ row_info->channels = 4;
+ row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+ }
+}
+#endif
+
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+/* If the bit depth is 8 and the color type is not a palette type expand the
+ * whole row to 16 bits. Has no effect otherwise.
+ */
+static void
+png_do_expand_16(png_row_infop row_info, png_bytep row)
+{
+ if (row_info->bit_depth == 8 &&
+ row_info->color_type != PNG_COLOR_TYPE_PALETTE)
+ {
+ /* The row have a sequence of bytes containing [0..255] and we need
+ * to turn it into another row containing [0..65535], to do this we
+ * calculate:
+ *
+ * (input / 255) * 65535
+ *
+ * Which happens to be exactly input * 257 and this can be achieved
+ * simply by byte replication in place (copying backwards).
+ */
+ png_byte *sp = row + row_info->rowbytes; /* source, last byte + 1 */
+ png_byte *dp = sp + row_info->rowbytes; /* destination, end + 1 */
+ while (dp > sp)
+ {
+ dp[-2] = dp[-1] = *--sp; dp -= 2;
+ }
+
+ row_info->rowbytes *= 2;
+ row_info->bit_depth = 16;
+ row_info->pixel_depth = (png_byte)(row_info->channels * 16);
+ }
+}
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+static void
+png_do_quantize(png_row_infop row_info, png_bytep row,
+ png_const_bytep palette_lookup, png_const_bytep quantize_lookup)
+{
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+
+ png_debug(1, "in png_do_quantize");
+
+ if (row_info->bit_depth == 8)
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB && palette_lookup)
+ {
+ int r, g, b, p;
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ r = *sp++;
+ g = *sp++;
+ b = *sp++;
+
+ /* This looks real messy, but the compiler will reduce
+ * it down to a reasonable formula. For example, with
+ * 5 bits per color, we get:
+ * p = (((r >> 3) & 0x1f) << 10) |
+ * (((g >> 3) & 0x1f) << 5) |
+ * ((b >> 3) & 0x1f);
+ */
+ p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) &
+ ((1 << PNG_QUANTIZE_RED_BITS) - 1)) <<
+ (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) |
+ (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) &
+ ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) <<
+ (PNG_QUANTIZE_BLUE_BITS)) |
+ ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) &
+ ((1 << PNG_QUANTIZE_BLUE_BITS) - 1));
+
+ *dp++ = palette_lookup[p];
+ }
+
+ row_info->color_type = PNG_COLOR_TYPE_PALETTE;
+ row_info->channels = 1;
+ row_info->pixel_depth = row_info->bit_depth;
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+ }
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
+ palette_lookup != NULL)
+ {
+ int r, g, b, p;
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ r = *sp++;
+ g = *sp++;
+ b = *sp++;
+ sp++;
+
+ p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) &
+ ((1 << PNG_QUANTIZE_RED_BITS) - 1)) <<
+ (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) |
+ (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) &
+ ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) <<
+ (PNG_QUANTIZE_BLUE_BITS)) |
+ ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) &
+ ((1 << PNG_QUANTIZE_BLUE_BITS) - 1));
+
+ *dp++ = palette_lookup[p];
+ }
+
+ row_info->color_type = PNG_COLOR_TYPE_PALETTE;
+ row_info->channels = 1;
+ row_info->pixel_depth = row_info->bit_depth;
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+ }
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
+ quantize_lookup)
+ {
+ sp = row;
+
+ for (i = 0; i < row_width; i++, sp++)
+ {
+ *sp = quantize_lookup[*sp];
+ }
+ }
+ }
+}
+#endif /* READ_QUANTIZE */
+
+/* Transform the row. The order of transformations is significant,
+ * and is very touchy. If you add a transformation, take care to
+ * decide how it fits in with the other transformations here.
+ */
+void /* PRIVATE */
+png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
+{
+ png_debug(1, "in png_do_read_transformations");
+
+ if (png_ptr->row_buf == NULL)
+ {
+ /* Prior to 1.5.4 this output row/pass where the NULL pointer is, but this
+ * error is incredibly rare and incredibly easy to debug without this
+ * information.
+ */
+ png_error(png_ptr, "NULL row buffer");
+ }
+
+ /* The following is debugging; prior to 1.5.4 the code was never compiled in;
+ * in 1.5.4 PNG_FLAG_DETECT_UNINITIALIZED was added and the macro
+ * PNG_WARN_UNINITIALIZED_ROW removed. In 1.6 the new flag is set only for
+ * all transformations, however in practice the ROW_INIT always gets done on
+ * demand, if necessary.
+ */
+ if ((png_ptr->flags & PNG_FLAG_DETECT_UNINITIALIZED) != 0 &&
+ (png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
+ {
+ /* Application has failed to call either png_read_start_image() or
+ * png_read_update_info() after setting transforms that expand pixels.
+ * This check added to libpng-1.2.19 (but not enabled until 1.5.4).
+ */
+ png_error(png_ptr, "Uninitialized row");
+ }
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ if ((png_ptr->transformations & PNG_EXPAND) != 0)
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+#ifdef PNG_ARM_NEON_INTRINSICS_AVAILABLE
+ if ((png_ptr->num_trans > 0) && (png_ptr->bit_depth == 8))
+ {
+ if (png_ptr->riffled_palette == NULL)
+ {
+ /* Initialize the accelerated palette expansion. */
+ png_ptr->riffled_palette =
+ (png_bytep)png_malloc(png_ptr, 256 * 4);
+ png_riffle_palette_neon(png_ptr);
+ }
+ }
+#endif
+ png_do_expand_palette(png_ptr, row_info, png_ptr->row_buf + 1,
+ png_ptr->palette, png_ptr->trans_alpha, png_ptr->num_trans);
+ }
+
+ else
+ {
+ if (png_ptr->num_trans != 0 &&
+ (png_ptr->transformations & PNG_EXPAND_tRNS) != 0)
+ png_do_expand(row_info, png_ptr->row_buf + 1,
+ &(png_ptr->trans_color));
+
+ else
+ png_do_expand(row_info, png_ptr->row_buf + 1, NULL);
+ }
+ }
+#endif
+
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+ if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 &&
+ (png_ptr->transformations & PNG_COMPOSE) == 0 &&
+ (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+ row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
+ png_do_strip_channel(row_info, png_ptr->row_buf + 1,
+ 0 /* at_start == false, because SWAP_ALPHA happens later */);
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
+ {
+ int rgb_error =
+ png_do_rgb_to_gray(png_ptr, row_info,
+ png_ptr->row_buf + 1);
+
+ if (rgb_error != 0)
+ {
+ png_ptr->rgb_to_gray_status=1;
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
+ PNG_RGB_TO_GRAY_WARN)
+ png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel");
+
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
+ PNG_RGB_TO_GRAY_ERR)
+ png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel");
+ }
+ }
+#endif
+
+/* From Andreas Dilger e-mail to png-implement, 26 March 1998:
+ *
+ * In most cases, the "simple transparency" should be done prior to doing
+ * gray-to-RGB, or you will have to test 3x as many bytes to check if a
+ * pixel is transparent. You would also need to make sure that the
+ * transparency information is upgraded to RGB.
+ *
+ * To summarize, the current flow is:
+ * - Gray + simple transparency -> compare 1 or 2 gray bytes and composite
+ * with background "in place" if transparent,
+ * convert to RGB if necessary
+ * - Gray + alpha -> composite with gray background and remove alpha bytes,
+ * convert to RGB if necessary
+ *
+ * To support RGB backgrounds for gray images we need:
+ * - Gray + simple transparency -> convert to RGB + simple transparency,
+ * compare 3 or 6 bytes and composite with
+ * background "in place" if transparent
+ * (3x compare/pixel compared to doing
+ * composite with gray bkgrnd)
+ * - Gray + alpha -> convert to RGB + alpha, composite with background and
+ * remove alpha bytes (3x float
+ * operations/pixel compared with composite
+ * on gray background)
+ *
+ * Greg's change will do this. The reason it wasn't done before is for
+ * performance, as this increases the per-pixel operations. If we would check
+ * in advance if the background was gray or RGB, and position the gray-to-RGB
+ * transform appropriately, then it would save a lot of work/time.
+ */
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+ /* If gray -> RGB, do so now only if background is non-gray; else do later
+ * for performance reasons
+ */
+ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0 &&
+ (png_ptr->mode & PNG_BACKGROUND_IS_GRAY) == 0)
+ png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1);
+#endif
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+ defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+ if ((png_ptr->transformations & PNG_COMPOSE) != 0)
+ png_do_compose(row_info, png_ptr->row_buf + 1, png_ptr);
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if ((png_ptr->transformations & PNG_GAMMA) != 0 &&
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ /* Because RGB_TO_GRAY does the gamma transform. */
+ (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0 &&
+#endif
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+ defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+ /* Because PNG_COMPOSE does the gamma transform if there is something to
+ * do (if there is an alpha channel or transparency.)
+ */
+ !((png_ptr->transformations & PNG_COMPOSE) != 0 &&
+ ((png_ptr->num_trans != 0) ||
+ (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)) &&
+#endif
+ /* Because png_init_read_transformations transforms the palette, unless
+ * RGB_TO_GRAY will do the transform.
+ */
+ (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE))
+ png_do_gamma(row_info, png_ptr->row_buf + 1, png_ptr);
+#endif
+
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+ if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 &&
+ (png_ptr->transformations & PNG_COMPOSE) != 0 &&
+ (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+ row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
+ png_do_strip_channel(row_info, png_ptr->row_buf + 1,
+ 0 /* at_start == false, because SWAP_ALPHA happens later */);
+#endif
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+ if ((png_ptr->transformations & PNG_ENCODE_ALPHA) != 0 &&
+ (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+ png_do_encode_alpha(row_info, png_ptr->row_buf + 1, png_ptr);
+#endif
+
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+ if ((png_ptr->transformations & PNG_SCALE_16_TO_8) != 0)
+ png_do_scale_16_to_8(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+ /* There is no harm in doing both of these because only one has any effect,
+ * by putting the 'scale' option first if the app asks for scale (either by
+ * calling the API or in a TRANSFORM flag) this is what happens.
+ */
+ if ((png_ptr->transformations & PNG_16_TO_8) != 0)
+ png_do_chop(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+ if ((png_ptr->transformations & PNG_QUANTIZE) != 0)
+ {
+ png_do_quantize(row_info, png_ptr->row_buf + 1,
+ png_ptr->palette_lookup, png_ptr->quantize_index);
+
+ if (row_info->rowbytes == 0)
+ png_error(png_ptr, "png_do_quantize returned rowbytes=0");
+ }
+#endif /* READ_QUANTIZE */
+
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+ /* Do the expansion now, after all the arithmetic has been done. Notice
+ * that previous transformations can handle the PNG_EXPAND_16 flag if this
+ * is efficient (particularly true in the case of gamma correction, where
+ * better accuracy results faster!)
+ */
+ if ((png_ptr->transformations & PNG_EXPAND_16) != 0)
+ png_do_expand_16(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+ /* NOTE: moved here in 1.5.4 (from much later in this list.) */
+ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0 &&
+ (png_ptr->mode & PNG_BACKGROUND_IS_GRAY) != 0)
+ png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_INVERT_SUPPORTED
+ if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
+ png_do_invert(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+ if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0)
+ png_do_read_invert_alpha(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_SHIFT_SUPPORTED
+ if ((png_ptr->transformations & PNG_SHIFT) != 0)
+ png_do_unshift(row_info, png_ptr->row_buf + 1,
+ &(png_ptr->shift));
+#endif
+
+#ifdef PNG_READ_PACK_SUPPORTED
+ if ((png_ptr->transformations & PNG_PACK) != 0)
+ png_do_unpack(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
+ /* Added at libpng-1.5.10 */
+ if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
+ png_ptr->num_palette_max >= 0)
+ png_do_check_palette_indexes(png_ptr, row_info);
+#endif
+
+#ifdef PNG_READ_BGR_SUPPORTED
+ if ((png_ptr->transformations & PNG_BGR) != 0)
+ png_do_bgr(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
+ png_do_packswap(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_FILLER_SUPPORTED
+ if ((png_ptr->transformations & PNG_FILLER) != 0)
+ png_do_read_filler(row_info, png_ptr->row_buf + 1,
+ (png_uint_32)png_ptr->filler, png_ptr->flags);
+#endif
+
+#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
+ if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0)
+ png_do_read_swap_alpha(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+#ifdef PNG_READ_SWAP_SUPPORTED
+ if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
+ png_do_swap(row_info, png_ptr->row_buf + 1);
+#endif
+#endif
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+ if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
+ {
+ if (png_ptr->read_user_transform_fn != NULL)
+ (*(png_ptr->read_user_transform_fn)) /* User read transform function */
+ (png_ptr, /* png_ptr */
+ row_info, /* row_info: */
+ /* png_uint_32 width; width of row */
+ /* size_t rowbytes; number of bytes in row */
+ /* png_byte color_type; color type of pixels */
+ /* png_byte bit_depth; bit depth of samples */
+ /* png_byte channels; number of channels (1-4) */
+ /* png_byte pixel_depth; bits per pixel (depth*channels) */
+ png_ptr->row_buf + 1); /* start of pixel data for row */
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+ if (png_ptr->user_transform_depth != 0)
+ row_info->bit_depth = png_ptr->user_transform_depth;
+
+ if (png_ptr->user_transform_channels != 0)
+ row_info->channels = png_ptr->user_transform_channels;
+#endif
+ row_info->pixel_depth = (png_byte)(row_info->bit_depth *
+ row_info->channels);
+
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_info->width);
+ }
+#endif
+}
+
+#endif /* READ_TRANSFORMS */
+#endif /* READ */
diff --git a/libs/imagequant/external/libpng/pngrutil.c b/libs/imagequant/external/libpng/pngrutil.c
new file mode 100644
index 00000000..7d9a0018
--- /dev/null
+++ b/libs/imagequant/external/libpng/pngrutil.c
@@ -0,0 +1,4707 @@
+/* pngrutil.c - utilities to read a PNG file
+ *
+ * Copyright (c) 2018-2025 Cosmin Truta
+ * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file contains routines that are only called from within
+ * libpng itself during the course of reading an image.
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+/* The minimum 'zlib' stream is assumed to be just the 2 byte header, 5 bytes
+ * minimum 'deflate' stream, and the 4 byte checksum.
+ */
+#define LZ77Min (2U+5U+4U)
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+/* Arrays to facilitate interlacing - use pass (0 - 6) as index. */
+
+/* Start of interlace block */
+static const png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+/* Offset to next interlace block */
+static const png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+/* Start of interlace block in the y direction */
+static const png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+/* Offset to next interlace block in the y direction */
+static const png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+
+/* TODO: Move these arrays to a common utility module to avoid duplication. */
+#endif
+
+png_uint_32 PNGAPI
+png_get_uint_31(png_const_structrp png_ptr, png_const_bytep buf)
+{
+ png_uint_32 uval = png_get_uint_32(buf);
+
+ if (uval > PNG_UINT_31_MAX)
+ png_error(png_ptr, "PNG unsigned integer out of range");
+
+ return uval;
+}
+
+#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
+/* NOTE: the read macros will obscure these definitions, so that if
+ * PNG_USE_READ_MACROS is set the library will not use them internally,
+ * but the APIs will still be available externally.
+ *
+ * The parentheses around "PNGAPI function_name" in the following three
+ * functions are necessary because they allow the macros to co-exist with
+ * these (unused but exported) functions.
+ */
+
+/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */
+png_uint_32 (PNGAPI
+png_get_uint_32)(png_const_bytep buf)
+{
+ png_uint_32 uval =
+ ((png_uint_32)(*(buf )) << 24) +
+ ((png_uint_32)(*(buf + 1)) << 16) +
+ ((png_uint_32)(*(buf + 2)) << 8) +
+ ((png_uint_32)(*(buf + 3)) ) ;
+
+ return uval;
+}
+
+/* Grab a signed 32-bit integer from a buffer in big-endian format. The
+ * data is stored in the PNG file in two's complement format and there
+ * is no guarantee that a 'png_int_32' is exactly 32 bits, therefore
+ * the following code does a two's complement to native conversion.
+ */
+png_int_32 (PNGAPI
+png_get_int_32)(png_const_bytep buf)
+{
+ png_uint_32 uval = png_get_uint_32(buf);
+ if ((uval & 0x80000000) == 0) /* non-negative */
+ return (png_int_32)uval;
+
+ uval = (uval ^ 0xffffffff) + 1; /* 2's complement: -x = ~x+1 */
+ if ((uval & 0x80000000) == 0) /* no overflow */
+ return -(png_int_32)uval;
+ /* The following has to be safe; this function only gets called on PNG data
+ * and if we get here that data is invalid. 0 is the most safe value and
+ * if not then an attacker would surely just generate a PNG with 0 instead.
+ */
+ return 0;
+}
+
+/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */
+png_uint_16 (PNGAPI
+png_get_uint_16)(png_const_bytep buf)
+{
+ /* ANSI-C requires an int value to accommodate at least 16 bits so this
+ * works and allows the compiler not to worry about possible narrowing
+ * on 32-bit systems. (Pre-ANSI systems did not make integers smaller
+ * than 16 bits either.)
+ */
+ unsigned int val =
+ ((unsigned int)(*buf) << 8) +
+ ((unsigned int)(*(buf + 1)));
+
+ return (png_uint_16)val;
+}
+
+#endif /* READ_INT_FUNCTIONS */
+
+/* Read and check the PNG file signature */
+void /* PRIVATE */
+png_read_sig(png_structrp png_ptr, png_inforp info_ptr)
+{
+ size_t num_checked, num_to_check;
+
+ /* Exit if the user application does not expect a signature. */
+ if (png_ptr->sig_bytes >= 8)
+ return;
+
+ num_checked = png_ptr->sig_bytes;
+ num_to_check = 8 - num_checked;
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE;
+#endif
+
+ /* The signature must be serialized in a single I/O call. */
+ png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
+ png_ptr->sig_bytes = 8;
+
+ if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check) != 0)
+ {
+ if (num_checked < 4 &&
+ png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4) != 0)
+ png_error(png_ptr, "Not a PNG file");
+ else
+ png_error(png_ptr, "PNG file corrupted by ASCII conversion");
+ }
+ if (num_checked < 3)
+ png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
+}
+
+/* This function is called to verify that a chunk name is valid.
+ * Do this using the bit-whacking approach from contrib/tools/pngfix.c
+ *
+ * Copied from libpng 1.7.
+ */
+static int
+check_chunk_name(png_uint_32 name)
+{
+ png_uint_32 t;
+
+ /* Remove bit 5 from all but the reserved byte; this means
+ * every 8-bit unit must be in the range 65-90 to be valid.
+ * So bit 5 must be zero, bit 6 must be set and bit 7 zero.
+ */
+ name &= ~PNG_U32(32,32,0,32);
+ t = (name & ~0x1f1f1f1fU) ^ 0x40404040U;
+
+ /* Subtract 65 for each 8-bit quantity, this must not
+ * overflow and each byte must then be in the range 0-25.
+ */
+ name -= PNG_U32(65,65,65,65);
+ t |= name;
+
+ /* Subtract 26, handling the overflow which should set the
+ * top three bits of each byte.
+ */
+ name -= PNG_U32(25,25,25,26);
+ t |= ~name;
+
+ return (t & 0xe0e0e0e0U) == 0U;
+}
+
+/* Read the chunk header (length + type name).
+ * Put the type name into png_ptr->chunk_name, and return the length.
+ */
+png_uint_32 /* PRIVATE */
+png_read_chunk_header(png_structrp png_ptr)
+{
+ png_byte buf[8];
+ png_uint_32 chunk_name, length;
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_HDR;
+#endif
+
+ /* Read the length and the chunk name. png_struct::chunk_name is immediately
+ * updated even if they are detectably wrong. This aids error message
+ * handling by allowing png_chunk_error to be used.
+ */
+ png_read_data(png_ptr, buf, 8);
+ length = png_get_uint_31(png_ptr, buf);
+ png_ptr->chunk_name = chunk_name = PNG_CHUNK_FROM_STRING(buf+4);
+
+ /* Reset the crc and run it over the chunk name. */
+ png_reset_crc(png_ptr);
+ png_calculate_crc(png_ptr, buf + 4, 4);
+
+ png_debug2(0, "Reading chunk typeid = 0x%lx, length = %lu",
+ (unsigned long)png_ptr->chunk_name, (unsigned long)length);
+
+ /* Sanity check the length (first by <= 0x80) and the chunk name. An error
+ * here indicates a broken stream and libpng has no recovery from this.
+ */
+ if (buf[0] >= 0x80U)
+ png_chunk_error(png_ptr, "bad header (invalid length)");
+
+ /* Check to see if chunk name is valid. */
+ if (!check_chunk_name(chunk_name))
+ png_chunk_error(png_ptr, "bad header (invalid type)");
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_DATA;
+#endif
+
+ return length;
+}
+
+/* Read data, and (optionally) run it through the CRC. */
+void /* PRIVATE */
+png_crc_read(png_structrp png_ptr, png_bytep buf, png_uint_32 length)
+{
+ if (png_ptr == NULL)
+ return;
+
+ png_read_data(png_ptr, buf, length);
+ png_calculate_crc(png_ptr, buf, length);
+}
+
+/* Compare the CRC stored in the PNG file with that calculated by libpng from
+ * the data it has read thus far.
+ */
+static int
+png_crc_error(png_structrp png_ptr, int handle_as_ancillary)
+{
+ png_byte crc_bytes[4];
+ png_uint_32 crc;
+ int need_crc = 1;
+
+ /* There are four flags two for ancillary and two for critical chunks. The
+ * default setting of these flags is all zero.
+ *
+ * PNG_FLAG_CRC_ANCILLARY_USE
+ * PNG_FLAG_CRC_ANCILLARY_NOWARN
+ * USE+NOWARN: no CRC calculation (implemented here), else;
+ * NOWARN: png_chunk_error on error (implemented in png_crc_finish)
+ * else: png_chunk_warning on error (implemented in png_crc_finish)
+ * This is the default.
+ *
+ * I.e. NOWARN without USE produces png_chunk_error. The default setting
+ * where neither are set does the same thing.
+ *
+ * PNG_FLAG_CRC_CRITICAL_USE
+ * PNG_FLAG_CRC_CRITICAL_IGNORE
+ * IGNORE: no CRC calculation (implemented here), else;
+ * USE: png_chunk_warning on error (implemented in png_crc_finish)
+ * else: png_chunk_error on error (implemented in png_crc_finish)
+ * This is the default.
+ *
+ * This arose because of original mis-implementation and has persisted for
+ * compatibility reasons.
+ *
+ * TODO: the flag names are internal so maybe this can be changed to
+ * something comprehensible.
+ */
+ if (handle_as_ancillary || PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0)
+ {
+ if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
+ (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
+ need_crc = 0;
+ }
+
+ else /* critical */
+ {
+ if ((png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) != 0)
+ need_crc = 0;
+ }
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_CRC;
+#endif
+
+ /* The chunk CRC must be serialized in a single I/O call. */
+ png_read_data(png_ptr, crc_bytes, 4);
+
+ if (need_crc != 0)
+ {
+ crc = png_get_uint_32(crc_bytes);
+ return crc != png_ptr->crc;
+ }
+
+ else
+ return 0;
+}
+
+/* Optionally skip data and then check the CRC. Depending on whether we
+ * are reading an ancillary or critical chunk, and how the program has set
+ * things up, we may calculate the CRC on the data and print a message.
+ * Returns '1' if there was a CRC error, '0' otherwise.
+ *
+ * There is one public version which is used in most places and another which
+ * takes the value for the 'critical' flag to check. This allows PLTE and IEND
+ * handling code to ignore the CRC error and removes some confusing code
+ * duplication.
+ */
+static int
+png_crc_finish_critical(png_structrp png_ptr, png_uint_32 skip,
+ int handle_as_ancillary)
+{
+ /* The size of the local buffer for inflate is a good guess as to a
+ * reasonable size to use for buffering reads from the application.
+ */
+ while (skip > 0)
+ {
+ png_uint_32 len;
+ png_byte tmpbuf[PNG_INFLATE_BUF_SIZE];
+
+ len = (sizeof tmpbuf);
+ if (len > skip)
+ len = skip;
+ skip -= len;
+
+ png_crc_read(png_ptr, tmpbuf, len);
+ }
+
+ /* If 'handle_as_ancillary' has been requested and this is a critical chunk
+ * but PNG_FLAG_CRC_CRITICAL_IGNORE was set then png_read_crc did not, in
+ * fact, calculate the CRC so the ANCILLARY settings should not be used
+ * instead.
+ */
+ if (handle_as_ancillary &&
+ (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) != 0)
+ handle_as_ancillary = 0;
+
+ /* TODO: this might be more comprehensible if png_crc_error was inlined here.
+ */
+ if (png_crc_error(png_ptr, handle_as_ancillary) != 0)
+ {
+ /* See above for the explanation of how the flags work. */
+ if (handle_as_ancillary || PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0 ?
+ (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) == 0 :
+ (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE) != 0)
+ png_chunk_warning(png_ptr, "CRC error");
+
+ else
+ png_chunk_error(png_ptr, "CRC error");
+
+ return 1;
+ }
+
+ return 0;
+}
+
+int /* PRIVATE */
+png_crc_finish(png_structrp png_ptr, png_uint_32 skip)
+{
+ return png_crc_finish_critical(png_ptr, skip, 0/*critical handling*/);
+}
+
+#if defined(PNG_READ_iCCP_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) ||\
+ defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_READ_sCAL_SUPPORTED) ||\
+ defined(PNG_READ_sPLT_SUPPORTED) || defined(PNG_READ_tEXt_SUPPORTED) ||\
+ defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_READ_eXIf_SUPPORTED) ||\
+ defined(PNG_SEQUENTIAL_READ_SUPPORTED)
+/* Manage the read buffer; this simply reallocates the buffer if it is not small
+ * enough (or if it is not allocated). The routine returns a pointer to the
+ * buffer; if an error occurs and 'warn' is set the routine returns NULL, else
+ * it will call png_error on failure.
+ */
+static png_bytep
+png_read_buffer(png_structrp png_ptr, png_alloc_size_t new_size)
+{
+ png_bytep buffer = png_ptr->read_buffer;
+
+ if (new_size > png_chunk_max(png_ptr)) return NULL;
+
+ if (buffer != NULL && new_size > png_ptr->read_buffer_size)
+ {
+ png_ptr->read_buffer = NULL;
+ png_ptr->read_buffer_size = 0;
+ png_free(png_ptr, buffer);
+ buffer = NULL;
+ }
+
+ if (buffer == NULL)
+ {
+ buffer = png_voidcast(png_bytep, png_malloc_base(png_ptr, new_size));
+
+ if (buffer != NULL)
+ {
+# ifndef PNG_NO_MEMZERO /* for detecting UIM bugs **only** */
+ memset(buffer, 0, new_size); /* just in case */
+# endif
+ png_ptr->read_buffer = buffer;
+ png_ptr->read_buffer_size = new_size;
+ }
+ }
+
+ return buffer;
+}
+#endif /* READ_iCCP|iTXt|pCAL|sCAL|sPLT|tEXt|zTXt|eXIf|SEQUENTIAL_READ */
+
+/* png_inflate_claim: claim the zstream for some nefarious purpose that involves
+ * decompression. Returns Z_OK on success, else a zlib error code. It checks
+ * the owner but, in final release builds, just issues a warning if some other
+ * chunk apparently owns the stream. Prior to release it does a png_error.
+ */
+static int
+png_inflate_claim(png_structrp png_ptr, png_uint_32 owner)
+{
+ if (png_ptr->zowner != 0)
+ {
+ char msg[64];
+
+ PNG_STRING_FROM_CHUNK(msg, png_ptr->zowner);
+ /* So the message that results is " using zstream"; this is an
+ * internal error, but is very useful for debugging. i18n requirements
+ * are minimal.
+ */
+ (void)png_safecat(msg, (sizeof msg), 4, " using zstream");
+#if PNG_RELEASE_BUILD
+ png_chunk_warning(png_ptr, msg);
+ png_ptr->zowner = 0;
+#else
+ png_chunk_error(png_ptr, msg);
+#endif
+ }
+
+ /* Implementation note: unlike 'png_deflate_claim' this internal function
+ * does not take the size of the data as an argument. Some efficiency could
+ * be gained by using this when it is known *if* the zlib stream itself does
+ * not record the number; however, this is an illusion: the original writer
+ * of the PNG may have selected a lower window size, and we really must
+ * follow that because, for systems with with limited capabilities, we
+ * would otherwise reject the application's attempts to use a smaller window
+ * size (zlib doesn't have an interface to say "this or lower"!).
+ *
+ * inflateReset2 was added to zlib 1.2.4; before this the window could not be
+ * reset, therefore it is necessary to always allocate the maximum window
+ * size with earlier zlibs just in case later compressed chunks need it.
+ */
+ {
+ int ret; /* zlib return code */
+#if ZLIB_VERNUM >= 0x1240
+ int window_bits = 0;
+
+# if defined(PNG_SET_OPTION_SUPPORTED) && defined(PNG_MAXIMUM_INFLATE_WINDOW)
+ if (((png_ptr->options >> PNG_MAXIMUM_INFLATE_WINDOW) & 3) ==
+ PNG_OPTION_ON)
+ {
+ window_bits = 15;
+ png_ptr->zstream_start = 0; /* fixed window size */
+ }
+
+ else
+ {
+ png_ptr->zstream_start = 1;
+ }
+# endif
+
+#endif /* ZLIB_VERNUM >= 0x1240 */
+
+ /* Set this for safety, just in case the previous owner left pointers to
+ * memory allocations.
+ */
+ png_ptr->zstream.next_in = NULL;
+ png_ptr->zstream.avail_in = 0;
+ png_ptr->zstream.next_out = NULL;
+ png_ptr->zstream.avail_out = 0;
+
+ if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0)
+ {
+#if ZLIB_VERNUM >= 0x1240
+ ret = inflateReset2(&png_ptr->zstream, window_bits);
+#else
+ ret = inflateReset(&png_ptr->zstream);
+#endif
+ }
+
+ else
+ {
+#if ZLIB_VERNUM >= 0x1240
+ ret = inflateInit2(&png_ptr->zstream, window_bits);
+#else
+ ret = inflateInit(&png_ptr->zstream);
+#endif
+
+ if (ret == Z_OK)
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED;
+ }
+
+#ifdef PNG_DISABLE_ADLER32_CHECK_SUPPORTED
+ if (((png_ptr->options >> PNG_IGNORE_ADLER32) & 3) == PNG_OPTION_ON)
+ /* Turn off validation of the ADLER32 checksum in IDAT chunks */
+ ret = inflateValidate(&png_ptr->zstream, 0);
+#endif
+
+ if (ret == Z_OK)
+ png_ptr->zowner = owner;
+
+ else
+ png_zstream_error(png_ptr, ret);
+
+ return ret;
+ }
+
+#ifdef window_bits
+# undef window_bits
+#endif
+}
+
+#if ZLIB_VERNUM >= 0x1240
+/* Handle the start of the inflate stream if we called inflateInit2(strm,0);
+ * in this case some zlib versions skip validation of the CINFO field and, in
+ * certain circumstances, libpng may end up displaying an invalid image, in
+ * contrast to implementations that call zlib in the normal way (e.g. libpng
+ * 1.5).
+ */
+int /* PRIVATE */
+png_zlib_inflate(png_structrp png_ptr, int flush)
+{
+ if (png_ptr->zstream_start && png_ptr->zstream.avail_in > 0)
+ {
+ if ((*png_ptr->zstream.next_in >> 4) > 7)
+ {
+ png_ptr->zstream.msg = "invalid window size (libpng)";
+ return Z_DATA_ERROR;
+ }
+
+ png_ptr->zstream_start = 0;
+ }
+
+ return inflate(&png_ptr->zstream, flush);
+}
+#endif /* Zlib >= 1.2.4 */
+
+#ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED
+#if defined(PNG_READ_zTXt_SUPPORTED) || defined (PNG_READ_iTXt_SUPPORTED)
+/* png_inflate now returns zlib error codes including Z_OK and Z_STREAM_END to
+ * allow the caller to do multiple calls if required. If the 'finish' flag is
+ * set Z_FINISH will be passed to the final inflate() call and Z_STREAM_END must
+ * be returned or there has been a problem, otherwise Z_SYNC_FLUSH is used and
+ * Z_OK or Z_STREAM_END will be returned on success.
+ *
+ * The input and output sizes are updated to the actual amounts of data consumed
+ * or written, not the amount available (as in a z_stream). The data pointers
+ * are not changed, so the next input is (data+input_size) and the next
+ * available output is (output+output_size).
+ */
+static int
+png_inflate(png_structrp png_ptr, png_uint_32 owner, int finish,
+ /* INPUT: */ png_const_bytep input, png_uint_32p input_size_ptr,
+ /* OUTPUT: */ png_bytep output, png_alloc_size_t *output_size_ptr)
+{
+ if (png_ptr->zowner == owner) /* Else not claimed */
+ {
+ int ret;
+ png_alloc_size_t avail_out = *output_size_ptr;
+ png_uint_32 avail_in = *input_size_ptr;
+
+ /* zlib can't necessarily handle more than 65535 bytes at once (i.e. it
+ * can't even necessarily handle 65536 bytes) because the type uInt is
+ * "16 bits or more". Consequently it is necessary to chunk the input to
+ * zlib. This code uses ZLIB_IO_MAX, from pngpriv.h, as the maximum (the
+ * maximum value that can be stored in a uInt.) It is possible to set
+ * ZLIB_IO_MAX to a lower value in pngpriv.h and this may sometimes have
+ * a performance advantage, because it reduces the amount of data accessed
+ * at each step and that may give the OS more time to page it in.
+ */
+ png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input);
+ /* avail_in and avail_out are set below from 'size' */
+ png_ptr->zstream.avail_in = 0;
+ png_ptr->zstream.avail_out = 0;
+
+ /* Read directly into the output if it is available (this is set to
+ * a local buffer below if output is NULL).
+ */
+ if (output != NULL)
+ png_ptr->zstream.next_out = output;
+
+ do
+ {
+ uInt avail;
+ Byte local_buffer[PNG_INFLATE_BUF_SIZE];
+
+ /* zlib INPUT BUFFER */
+ /* The setting of 'avail_in' used to be outside the loop; by setting it
+ * inside it is possible to chunk the input to zlib and simply rely on
+ * zlib to advance the 'next_in' pointer. This allows arbitrary
+ * amounts of data to be passed through zlib at the unavoidable cost of
+ * requiring a window save (memcpy of up to 32768 output bytes)
+ * every ZLIB_IO_MAX input bytes.
+ */
+ avail_in += png_ptr->zstream.avail_in; /* not consumed last time */
+
+ avail = ZLIB_IO_MAX;
+
+ if (avail_in < avail)
+ avail = (uInt)avail_in; /* safe: < than ZLIB_IO_MAX */
+
+ avail_in -= avail;
+ png_ptr->zstream.avail_in = avail;
+
+ /* zlib OUTPUT BUFFER */
+ avail_out += png_ptr->zstream.avail_out; /* not written last time */
+
+ avail = ZLIB_IO_MAX; /* maximum zlib can process */
+
+ if (output == NULL)
+ {
+ /* Reset the output buffer each time round if output is NULL and
+ * make available the full buffer, up to 'remaining_space'
+ */
+ png_ptr->zstream.next_out = local_buffer;
+ if ((sizeof local_buffer) < avail)
+ avail = (sizeof local_buffer);
+ }
+
+ if (avail_out < avail)
+ avail = (uInt)avail_out; /* safe: < ZLIB_IO_MAX */
+
+ png_ptr->zstream.avail_out = avail;
+ avail_out -= avail;
+
+ /* zlib inflate call */
+ /* In fact 'avail_out' may be 0 at this point, that happens at the end
+ * of the read when the final LZ end code was not passed at the end of
+ * the previous chunk of input data. Tell zlib if we have reached the
+ * end of the output buffer.
+ */
+ ret = PNG_INFLATE(png_ptr, avail_out > 0 ? Z_NO_FLUSH :
+ (finish ? Z_FINISH : Z_SYNC_FLUSH));
+ } while (ret == Z_OK);
+
+ /* For safety kill the local buffer pointer now */
+ if (output == NULL)
+ png_ptr->zstream.next_out = NULL;
+
+ /* Claw back the 'size' and 'remaining_space' byte counts. */
+ avail_in += png_ptr->zstream.avail_in;
+ avail_out += png_ptr->zstream.avail_out;
+
+ /* Update the input and output sizes; the updated values are the amount
+ * consumed or written, effectively the inverse of what zlib uses.
+ */
+ if (avail_out > 0)
+ *output_size_ptr -= avail_out;
+
+ if (avail_in > 0)
+ *input_size_ptr -= avail_in;
+
+ /* Ensure png_ptr->zstream.msg is set (even in the success case!) */
+ png_zstream_error(png_ptr, ret);
+ return ret;
+ }
+
+ else
+ {
+ /* This is a bad internal error. The recovery assigns to the zstream msg
+ * pointer, which is not owned by the caller, but this is safe; it's only
+ * used on errors!
+ */
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed");
+ return Z_STREAM_ERROR;
+ }
+}
+
+/*
+ * Decompress trailing data in a chunk. The assumption is that read_buffer
+ * points at an allocated area holding the contents of a chunk with a
+ * trailing compressed part. What we get back is an allocated area
+ * holding the original prefix part and an uncompressed version of the
+ * trailing part (the malloc area passed in is freed).
+ */
+static int
+png_decompress_chunk(png_structrp png_ptr,
+ png_uint_32 chunklength, png_uint_32 prefix_size,
+ png_alloc_size_t *newlength /* must be initialized to the maximum! */,
+ int terminate /*add a '\0' to the end of the uncompressed data*/)
+{
+ /* TODO: implement different limits for different types of chunk.
+ *
+ * The caller supplies *newlength set to the maximum length of the
+ * uncompressed data, but this routine allocates space for the prefix and
+ * maybe a '\0' terminator too. We have to assume that 'prefix_size' is
+ * limited only by the maximum chunk size.
+ */
+ png_alloc_size_t limit = png_chunk_max(png_ptr);
+
+ if (limit >= prefix_size + (terminate != 0))
+ {
+ int ret;
+
+ limit -= prefix_size + (terminate != 0);
+
+ if (limit < *newlength)
+ *newlength = limit;
+
+ /* Now try to claim the stream. */
+ ret = png_inflate_claim(png_ptr, png_ptr->chunk_name);
+
+ if (ret == Z_OK)
+ {
+ png_uint_32 lzsize = chunklength - prefix_size;
+
+ ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/,
+ /* input: */ png_ptr->read_buffer + prefix_size, &lzsize,
+ /* output: */ NULL, newlength);
+
+ if (ret == Z_STREAM_END)
+ {
+ /* Use 'inflateReset' here, not 'inflateReset2' because this
+ * preserves the previously decided window size (otherwise it would
+ * be necessary to store the previous window size.) In practice
+ * this doesn't matter anyway, because png_inflate will call inflate
+ * with Z_FINISH in almost all cases, so the window will not be
+ * maintained.
+ */
+ if (inflateReset(&png_ptr->zstream) == Z_OK)
+ {
+ /* Because of the limit checks above we know that the new,
+ * expanded, size will fit in a size_t (let alone an
+ * png_alloc_size_t). Use png_malloc_base here to avoid an
+ * extra OOM message.
+ */
+ png_alloc_size_t new_size = *newlength;
+ png_alloc_size_t buffer_size = prefix_size + new_size +
+ (terminate != 0);
+ png_bytep text = png_voidcast(png_bytep, png_malloc_base(png_ptr,
+ buffer_size));
+
+ if (text != NULL)
+ {
+ memset(text, 0, buffer_size);
+
+ ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/,
+ png_ptr->read_buffer + prefix_size, &lzsize,
+ text + prefix_size, newlength);
+
+ if (ret == Z_STREAM_END)
+ {
+ if (new_size == *newlength)
+ {
+ if (terminate != 0)
+ text[prefix_size + *newlength] = 0;
+
+ if (prefix_size > 0)
+ memcpy(text, png_ptr->read_buffer, prefix_size);
+
+ {
+ png_bytep old_ptr = png_ptr->read_buffer;
+
+ png_ptr->read_buffer = text;
+ png_ptr->read_buffer_size = buffer_size;
+ text = old_ptr; /* freed below */
+ }
+ }
+
+ else
+ {
+ /* The size changed on the second read, there can be no
+ * guarantee that anything is correct at this point.
+ * The 'msg' pointer has been set to "unexpected end of
+ * LZ stream", which is fine, but return an error code
+ * that the caller won't accept.
+ */
+ ret = PNG_UNEXPECTED_ZLIB_RETURN;
+ }
+ }
+
+ else if (ret == Z_OK)
+ ret = PNG_UNEXPECTED_ZLIB_RETURN; /* for safety */
+
+ /* Free the text pointer (this is the old read_buffer on
+ * success)
+ */
+ png_free(png_ptr, text);
+
+ /* This really is very benign, but it's still an error because
+ * the extra space may otherwise be used as a Trojan Horse.
+ */
+ if (ret == Z_STREAM_END &&
+ chunklength - prefix_size != lzsize)
+ png_chunk_benign_error(png_ptr, "extra compressed data");
+ }
+
+ else
+ {
+ /* Out of memory allocating the buffer */
+ ret = Z_MEM_ERROR;
+ png_zstream_error(png_ptr, Z_MEM_ERROR);
+ }
+ }
+
+ else
+ {
+ /* inflateReset failed, store the error message */
+ png_zstream_error(png_ptr, ret);
+ ret = PNG_UNEXPECTED_ZLIB_RETURN;
+ }
+ }
+
+ else if (ret == Z_OK)
+ ret = PNG_UNEXPECTED_ZLIB_RETURN;
+
+ /* Release the claimed stream */
+ png_ptr->zowner = 0;
+ }
+
+ else /* the claim failed */ if (ret == Z_STREAM_END) /* impossible! */
+ ret = PNG_UNEXPECTED_ZLIB_RETURN;
+
+ return ret;
+ }
+
+ else
+ {
+ /* Application/configuration limits exceeded */
+ png_zstream_error(png_ptr, Z_MEM_ERROR);
+ return Z_MEM_ERROR;
+ }
+}
+#endif /* READ_zTXt || READ_iTXt */
+#endif /* READ_COMPRESSED_TEXT */
+
+#ifdef PNG_READ_iCCP_SUPPORTED
+/* Perform a partial read and decompress, producing 'avail_out' bytes and
+ * reading from the current chunk as required.
+ */
+static int
+png_inflate_read(png_structrp png_ptr, png_bytep read_buffer, uInt read_size,
+ png_uint_32p chunk_bytes, png_bytep next_out, png_alloc_size_t *out_size,
+ int finish)
+{
+ if (png_ptr->zowner == png_ptr->chunk_name)
+ {
+ int ret;
+
+ /* next_in and avail_in must have been initialized by the caller. */
+ png_ptr->zstream.next_out = next_out;
+ png_ptr->zstream.avail_out = 0; /* set in the loop */
+
+ do
+ {
+ if (png_ptr->zstream.avail_in == 0)
+ {
+ if (read_size > *chunk_bytes)
+ read_size = (uInt)*chunk_bytes;
+ *chunk_bytes -= read_size;
+
+ if (read_size > 0)
+ png_crc_read(png_ptr, read_buffer, read_size);
+
+ png_ptr->zstream.next_in = read_buffer;
+ png_ptr->zstream.avail_in = read_size;
+ }
+
+ if (png_ptr->zstream.avail_out == 0)
+ {
+ uInt avail = ZLIB_IO_MAX;
+ if (avail > *out_size)
+ avail = (uInt)*out_size;
+ *out_size -= avail;
+
+ png_ptr->zstream.avail_out = avail;
+ }
+
+ /* Use Z_SYNC_FLUSH when there is no more chunk data to ensure that all
+ * the available output is produced; this allows reading of truncated
+ * streams.
+ */
+ ret = PNG_INFLATE(png_ptr, *chunk_bytes > 0 ?
+ Z_NO_FLUSH : (finish ? Z_FINISH : Z_SYNC_FLUSH));
+ }
+ while (ret == Z_OK && (*out_size > 0 || png_ptr->zstream.avail_out > 0));
+
+ *out_size += png_ptr->zstream.avail_out;
+ png_ptr->zstream.avail_out = 0; /* Should not be required, but is safe */
+
+ /* Ensure the error message pointer is always set: */
+ png_zstream_error(png_ptr, ret);
+ return ret;
+ }
+
+ else
+ {
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed");
+ return Z_STREAM_ERROR;
+ }
+}
+#endif /* READ_iCCP */
+
+/* CHUNK HANDLING */
+/* Read and check the IDHR chunk */
+static png_handle_result_code
+png_handle_IHDR(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_byte buf[13];
+ png_uint_32 width, height;
+ int bit_depth, color_type, compression_type, filter_type;
+ int interlace_type;
+
+ png_debug(1, "in png_handle_IHDR");
+
+ /* Length and position are checked by the caller. */
+
+ png_ptr->mode |= PNG_HAVE_IHDR;
+
+ png_crc_read(png_ptr, buf, 13);
+ png_crc_finish(png_ptr, 0);
+
+ width = png_get_uint_31(png_ptr, buf);
+ height = png_get_uint_31(png_ptr, buf + 4);
+ bit_depth = buf[8];
+ color_type = buf[9];
+ compression_type = buf[10];
+ filter_type = buf[11];
+ interlace_type = buf[12];
+
+ /* Set internal variables */
+ png_ptr->width = width;
+ png_ptr->height = height;
+ png_ptr->bit_depth = (png_byte)bit_depth;
+ png_ptr->interlaced = (png_byte)interlace_type;
+ png_ptr->color_type = (png_byte)color_type;
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ png_ptr->filter_type = (png_byte)filter_type;
+#endif
+ png_ptr->compression_type = (png_byte)compression_type;
+
+ /* Find number of channels */
+ switch (png_ptr->color_type)
+ {
+ default: /* invalid, png_set_IHDR calls png_error */
+ case PNG_COLOR_TYPE_GRAY:
+ case PNG_COLOR_TYPE_PALETTE:
+ png_ptr->channels = 1;
+ break;
+
+ case PNG_COLOR_TYPE_RGB:
+ png_ptr->channels = 3;
+ break;
+
+ case PNG_COLOR_TYPE_GRAY_ALPHA:
+ png_ptr->channels = 2;
+ break;
+
+ case PNG_COLOR_TYPE_RGB_ALPHA:
+ png_ptr->channels = 4;
+ break;
+ }
+
+ /* Set up other useful info */
+ png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth * png_ptr->channels);
+ png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->width);
+ png_debug1(3, "bit_depth = %d", png_ptr->bit_depth);
+ png_debug1(3, "channels = %d", png_ptr->channels);
+ png_debug1(3, "rowbytes = %lu", (unsigned long)png_ptr->rowbytes);
+
+ /* Rely on png_set_IHDR to completely validate the data and call png_error if
+ * it's wrong.
+ */
+ png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth,
+ color_type, interlace_type, compression_type, filter_type);
+
+ return handled_ok;
+ PNG_UNUSED(length)
+}
+
+/* Read and check the palette */
+/* TODO: there are several obvious errors in this code when handling
+ * out-of-place chunks and there is much over-complexity caused by trying to
+ * patch up the problems.
+ */
+static png_handle_result_code
+png_handle_PLTE(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_const_charp errmsg = NULL;
+
+ png_debug(1, "in png_handle_PLTE");
+
+ /* 1.6.47: consistency. This used to be especially treated as a critical
+ * error even in an image which is not colour mapped, there isn't a good
+ * justification for treating some errors here one way and others another so
+ * everything uses the same logic.
+ */
+ if ((png_ptr->mode & PNG_HAVE_PLTE) != 0)
+ errmsg = "duplicate";
+
+ else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+ errmsg = "out of place";
+
+ else if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0)
+ errmsg = "ignored in grayscale PNG";
+
+ else if (length > 3*PNG_MAX_PALETTE_LENGTH || (length % 3) != 0)
+ errmsg = "invalid";
+
+ /* This drops PLTE in favour of tRNS or bKGD because both of those chunks
+ * can have an effect on the rendering of the image whereas PLTE only matters
+ * in the case of an 8-bit display with a decoder which controls the palette.
+ *
+ * The alternative here is to ignore the error and store the palette anyway;
+ * destroying the tRNS will definately cause problems.
+ *
+ * NOTE: the case of PNG_COLOR_TYPE_PALETTE need not be considered because
+ * the png_handle_ routines for the three 'after PLTE' chunks tRNS, bKGD and
+ * hIST all check for a preceding PLTE in these cases.
+ */
+ else if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE &&
+ (png_has_chunk(png_ptr, tRNS) || png_has_chunk(png_ptr, bKGD)))
+ errmsg = "out of place";
+
+ else
+ {
+ /* If the palette has 256 or fewer entries but is too large for the bit
+ * depth we don't issue an error to preserve the behavior of previous
+ * libpng versions. We silently truncate the unused extra palette entries
+ * here.
+ */
+ const unsigned max_palette_length =
+ (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ?
+ 1U << png_ptr->bit_depth : PNG_MAX_PALETTE_LENGTH;
+
+ /* The cast is safe because 'length' is less than
+ * 3*PNG_MAX_PALETTE_LENGTH
+ */
+ const unsigned num = (length > 3U*max_palette_length) ?
+ max_palette_length : (unsigned)length / 3U;
+
+ unsigned i, j;
+ png_byte buf[3*PNG_MAX_PALETTE_LENGTH];
+ png_color palette[PNG_MAX_PALETTE_LENGTH];
+
+ /* Read the chunk into the buffer then read to the end of the chunk. */
+ png_crc_read(png_ptr, buf, num*3U);
+ png_crc_finish_critical(png_ptr, length - 3U*num,
+ /* Handle as ancillary if PLTE is optional: */
+ png_ptr->color_type != PNG_COLOR_TYPE_PALETTE);
+
+ for (i = 0U, j = 0U; i < num; i++)
+ {
+ palette[i].red = buf[j++];
+ palette[i].green = buf[j++];
+ palette[i].blue = buf[j++];
+ }
+
+ /* A valid PLTE chunk has been read */
+ png_ptr->mode |= PNG_HAVE_PLTE;
+
+ /* TODO: png_set_PLTE has the side effect of setting png_ptr->palette to
+ * its own copy of the palette. This has the side effect that when
+ * png_start_row is called (this happens after any call to
+ * png_read_update_info) the info_ptr palette gets changed. This is
+ * extremely unexpected and confusing.
+ *
+ * REVIEW: there have been consistent bugs in the past about gamma and
+ * similar transforms to colour mapped images being useless because the
+ * modified palette cannot be accessed because of the above.
+ *
+ * CONSIDER: Fix this by not sharing the palette in this way. But does
+ * this completely fix the problem?
+ */
+ png_set_PLTE(png_ptr, info_ptr, palette, num);
+ return handled_ok;
+ }
+
+ /* Here on error: errmsg is non NULL. */
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_error(png_ptr, errmsg);
+ }
+
+ else /* not critical to this image */
+ {
+ png_crc_finish_critical(png_ptr, length, 1/*handle as ancillary*/);
+ png_chunk_benign_error(png_ptr, errmsg);
+ }
+
+ /* Because PNG_UNUSED(errmsg) does not work if all the uses are compiled out
+ * (this does happen).
+ */
+ return errmsg != NULL ? handled_error : handled_error;
+}
+
+/* On read the IDAT chunk is always handled specially, even if marked for
+ * unknown handling (this is allowed), so:
+ */
+#define png_handle_IDAT NULL
+
+static png_handle_result_code
+png_handle_IEND(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_debug(1, "in png_handle_IEND");
+
+ png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND);
+
+ if (length != 0)
+ png_chunk_benign_error(png_ptr, "invalid");
+
+ png_crc_finish_critical(png_ptr, length, 1/*handle as ancillary*/);
+
+ return handled_ok;
+ PNG_UNUSED(info_ptr)
+}
+
+#ifdef PNG_READ_gAMA_SUPPORTED
+static png_handle_result_code
+png_handle_gAMA(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_uint_32 ugamma;
+ png_byte buf[4];
+
+ png_debug(1, "in png_handle_gAMA");
+
+ png_crc_read(png_ptr, buf, 4);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return handled_error;
+
+ ugamma = png_get_uint_32(buf);
+
+ if (ugamma > PNG_UINT_31_MAX)
+ {
+ png_chunk_benign_error(png_ptr, "invalid");
+ return handled_error;
+ }
+
+ png_set_gAMA_fixed(png_ptr, info_ptr, (png_fixed_point)/*SAFE*/ugamma);
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ /* PNGv3: chunk precedence for gamma is cICP, [iCCP], sRGB, gAMA. gAMA is
+ * at the end of the chain so simply check for an unset value.
+ */
+ if (png_ptr->chunk_gamma == 0)
+ png_ptr->chunk_gamma = (png_fixed_point)/*SAFE*/ugamma;
+#endif /*READ_GAMMA*/
+
+ return handled_ok;
+ PNG_UNUSED(length)
+}
+#else
+# define png_handle_gAMA NULL
+#endif
+
+#ifdef PNG_READ_sBIT_SUPPORTED
+static png_handle_result_code /* PRIVATE */
+png_handle_sBIT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ unsigned int truelen, i;
+ png_byte sample_depth;
+ png_byte buf[4];
+
+ png_debug(1, "in png_handle_sBIT");
+
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ truelen = 3;
+ sample_depth = 8;
+ }
+
+ else
+ {
+ truelen = png_ptr->channels;
+ sample_depth = png_ptr->bit_depth;
+ }
+
+ if (length != truelen)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "bad length");
+ return handled_error;
+ }
+
+ buf[0] = buf[1] = buf[2] = buf[3] = sample_depth;
+ png_crc_read(png_ptr, buf, truelen);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return handled_error;
+
+ for (i=0; i sample_depth)
+ {
+ png_chunk_benign_error(png_ptr, "invalid");
+ return handled_error;
+ }
+ }
+
+ if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ {
+ png_ptr->sig_bit.red = buf[0];
+ png_ptr->sig_bit.green = buf[1];
+ png_ptr->sig_bit.blue = buf[2];
+ png_ptr->sig_bit.alpha = buf[3];
+ }
+
+ else /* grayscale */
+ {
+ png_ptr->sig_bit.gray = buf[0];
+ png_ptr->sig_bit.red = buf[0];
+ png_ptr->sig_bit.green = buf[0];
+ png_ptr->sig_bit.blue = buf[0];
+ png_ptr->sig_bit.alpha = buf[1];
+ }
+
+ png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit));
+ return handled_ok;
+}
+#else
+# define png_handle_sBIT NULL
+#endif
+
+#ifdef PNG_READ_cHRM_SUPPORTED
+static png_int_32
+png_get_int_32_checked(png_const_bytep buf, int *error)
+{
+ png_uint_32 uval = png_get_uint_32(buf);
+ if ((uval & 0x80000000) == 0) /* non-negative */
+ return (png_int_32)uval;
+
+ uval = (uval ^ 0xffffffff) + 1; /* 2's complement: -x = ~x+1 */
+ if ((uval & 0x80000000) == 0) /* no overflow */
+ return -(png_int_32)uval;
+
+ /* This version of png_get_int_32 has a way of returning the error to the
+ * caller, so:
+ */
+ *error = 1;
+ return 0; /* Safe */
+}
+
+static png_handle_result_code /* PRIVATE */
+png_handle_cHRM(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ int error = 0;
+ png_xy xy;
+ png_byte buf[32];
+
+ png_debug(1, "in png_handle_cHRM");
+
+ png_crc_read(png_ptr, buf, 32);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return handled_error;
+
+ xy.whitex = png_get_int_32_checked(buf + 0, &error);
+ xy.whitey = png_get_int_32_checked(buf + 4, &error);
+ xy.redx = png_get_int_32_checked(buf + 8, &error);
+ xy.redy = png_get_int_32_checked(buf + 12, &error);
+ xy.greenx = png_get_int_32_checked(buf + 16, &error);
+ xy.greeny = png_get_int_32_checked(buf + 20, &error);
+ xy.bluex = png_get_int_32_checked(buf + 24, &error);
+ xy.bluey = png_get_int_32_checked(buf + 28, &error);
+
+ if (error)
+ {
+ png_chunk_benign_error(png_ptr, "invalid");
+ return handled_error;
+ }
+
+ /* png_set_cHRM may complain about some of the values but this doesn't matter
+ * because it was a cHRM and it did have vaguely (if, perhaps, ridiculous)
+ * values. Ridiculousity will be checked if the values are used later.
+ */
+ png_set_cHRM_fixed(png_ptr, info_ptr, xy.whitex, xy.whitey, xy.redx, xy.redy,
+ xy.greenx, xy.greeny, xy.bluex, xy.bluey);
+
+ /* We only use 'chromaticities' for RGB to gray */
+# ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ /* There is no need to check sRGB here, cICP is NYI and iCCP is not
+ * supported so just check mDCV.
+ */
+ if (!png_has_chunk(png_ptr, mDCV))
+ {
+ png_ptr->chromaticities = xy;
+ }
+# endif /* READ_RGB_TO_GRAY */
+
+ return handled_ok;
+ PNG_UNUSED(length)
+}
+#else
+# define png_handle_cHRM NULL
+#endif
+
+#ifdef PNG_READ_sRGB_SUPPORTED
+static png_handle_result_code /* PRIVATE */
+png_handle_sRGB(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_byte intent;
+
+ png_debug(1, "in png_handle_sRGB");
+
+ png_crc_read(png_ptr, &intent, 1);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return handled_error;
+
+ /* This checks the range of the "rendering intent" because it is specified in
+ * the PNG spec itself; the "reserved" values will result in the chunk not
+ * being accepted, just as they do with the various "reserved" values in
+ * IHDR.
+ */
+ if (intent > 3/*PNGv3 spec*/)
+ {
+ png_chunk_benign_error(png_ptr, "invalid");
+ return handled_error;
+ }
+
+ png_set_sRGB(png_ptr, info_ptr, intent);
+ /* NOTE: png_struct::chromaticities is not set here because the RGB to gray
+ * coefficients are known without a need for the chromaticities.
+ */
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ /* PNGv3: chunk precedence for gamma is cICP, [iCCP], sRGB, gAMA. iCCP is
+ * not supported by libpng so the only requirement is to check for cICP
+ * setting the gamma (this is NYI, but this check is safe.)
+ */
+ if (!png_has_chunk(png_ptr, cICP) || png_ptr->chunk_gamma == 0)
+ png_ptr->chunk_gamma = PNG_GAMMA_sRGB_INVERSE;
+#endif /*READ_GAMMA*/
+
+ return handled_ok;
+ PNG_UNUSED(length)
+}
+#else
+# define png_handle_sRGB NULL
+#endif /* READ_sRGB */
+
+#ifdef PNG_READ_iCCP_SUPPORTED
+static png_handle_result_code /* PRIVATE */
+png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+/* Note: this does not properly handle profiles that are > 64K under DOS */
+{
+ png_const_charp errmsg = NULL; /* error message output, or no error */
+ int finished = 0; /* crc checked */
+
+ png_debug(1, "in png_handle_iCCP");
+
+ /* PNGv3: allow PNG files with both sRGB and iCCP because the PNG spec only
+ * ever said that there "should" be only one, not "shall" and the PNGv3
+ * colour chunk precedence rules give a handling for this case anyway.
+ */
+ {
+ uInt read_length, keyword_length;
+ char keyword[81];
+
+ /* Find the keyword; the keyword plus separator and compression method
+ * bytes can be at most 81 characters long.
+ */
+ read_length = 81; /* maximum */
+ if (read_length > length)
+ read_length = (uInt)/*SAFE*/length;
+
+ png_crc_read(png_ptr, (png_bytep)keyword, read_length);
+ length -= read_length;
+
+ if (length < LZ77Min)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "too short");
+ return handled_error;
+ }
+
+ keyword_length = 0;
+ while (keyword_length < 80 && keyword_length < read_length &&
+ keyword[keyword_length] != 0)
+ ++keyword_length;
+
+ /* TODO: make the keyword checking common */
+ if (keyword_length >= 1 && keyword_length <= 79)
+ {
+ /* We only understand '0' compression - deflate - so if we get a
+ * different value we can't safely decode the chunk.
+ */
+ if (keyword_length+1 < read_length &&
+ keyword[keyword_length+1] == PNG_COMPRESSION_TYPE_BASE)
+ {
+ read_length -= keyword_length+2;
+
+ if (png_inflate_claim(png_ptr, png_iCCP) == Z_OK)
+ {
+ Byte profile_header[132]={0};
+ Byte local_buffer[PNG_INFLATE_BUF_SIZE];
+ png_alloc_size_t size = (sizeof profile_header);
+
+ png_ptr->zstream.next_in = (Bytef*)keyword + (keyword_length+2);
+ png_ptr->zstream.avail_in = read_length;
+ (void)png_inflate_read(png_ptr, local_buffer,
+ (sizeof local_buffer), &length, profile_header, &size,
+ 0/*finish: don't, because the output is too small*/);
+
+ if (size == 0)
+ {
+ /* We have the ICC profile header; do the basic header checks.
+ */
+ png_uint_32 profile_length = png_get_uint_32(profile_header);
+
+ if (png_icc_check_length(png_ptr, keyword, profile_length) !=
+ 0)
+ {
+ /* The length is apparently ok, so we can check the 132
+ * byte header.
+ */
+ if (png_icc_check_header(png_ptr, keyword, profile_length,
+ profile_header, png_ptr->color_type) != 0)
+ {
+ /* Now read the tag table; a variable size buffer is
+ * needed at this point, allocate one for the whole
+ * profile. The header check has already validated
+ * that none of this stuff will overflow.
+ */
+ png_uint_32 tag_count =
+ png_get_uint_32(profile_header + 128);
+ png_bytep profile = png_read_buffer(png_ptr,
+ profile_length);
+
+ if (profile != NULL)
+ {
+ memcpy(profile, profile_header,
+ (sizeof profile_header));
+
+ size = 12 * tag_count;
+
+ (void)png_inflate_read(png_ptr, local_buffer,
+ (sizeof local_buffer), &length,
+ profile + (sizeof profile_header), &size, 0);
+
+ /* Still expect a buffer error because we expect
+ * there to be some tag data!
+ */
+ if (size == 0)
+ {
+ if (png_icc_check_tag_table(png_ptr,
+ keyword, profile_length, profile) != 0)
+ {
+ /* The profile has been validated for basic
+ * security issues, so read the whole thing in.
+ */
+ size = profile_length - (sizeof profile_header)
+ - 12 * tag_count;
+
+ (void)png_inflate_read(png_ptr, local_buffer,
+ (sizeof local_buffer), &length,
+ profile + (sizeof profile_header) +
+ 12 * tag_count, &size, 1/*finish*/);
+
+ if (length > 0 && !(png_ptr->flags &
+ PNG_FLAG_BENIGN_ERRORS_WARN))
+ errmsg = "extra compressed data";
+
+ /* But otherwise allow extra data: */
+ else if (size == 0)
+ {
+ if (length > 0)
+ {
+ /* This can be handled completely, so
+ * keep going.
+ */
+ png_chunk_warning(png_ptr,
+ "extra compressed data");
+ }
+
+ png_crc_finish(png_ptr, length);
+ finished = 1;
+
+ /* Steal the profile for info_ptr. */
+ if (info_ptr != NULL)
+ {
+ png_free_data(png_ptr, info_ptr,
+ PNG_FREE_ICCP, 0);
+
+ info_ptr->iccp_name = png_voidcast(char*,
+ png_malloc_base(png_ptr,
+ keyword_length+1));
+ if (info_ptr->iccp_name != NULL)
+ {
+ memcpy(info_ptr->iccp_name, keyword,
+ keyword_length+1);
+ info_ptr->iccp_proflen =
+ profile_length;
+ info_ptr->iccp_profile = profile;
+ png_ptr->read_buffer = NULL; /*steal*/
+ info_ptr->free_me |= PNG_FREE_ICCP;
+ info_ptr->valid |= PNG_INFO_iCCP;
+ }
+
+ else
+ errmsg = "out of memory";
+ }
+
+ /* else the profile remains in the read
+ * buffer which gets reused for subsequent
+ * chunks.
+ */
+
+ if (errmsg == NULL)
+ {
+ png_ptr->zowner = 0;
+ return handled_ok;
+ }
+ }
+ if (errmsg == NULL)
+ errmsg = png_ptr->zstream.msg;
+ }
+ /* else png_icc_check_tag_table output an error */
+ }
+ else /* profile truncated */
+ errmsg = png_ptr->zstream.msg;
+ }
+
+ else
+ errmsg = "out of memory";
+ }
+
+ /* else png_icc_check_header output an error */
+ }
+
+ /* else png_icc_check_length output an error */
+ }
+
+ else /* profile truncated */
+ errmsg = png_ptr->zstream.msg;
+
+ /* Release the stream */
+ png_ptr->zowner = 0;
+ }
+
+ else /* png_inflate_claim failed */
+ errmsg = png_ptr->zstream.msg;
+ }
+
+ else
+ errmsg = "bad compression method"; /* or missing */
+ }
+
+ else
+ errmsg = "bad keyword";
+ }
+
+ /* Failure: the reason is in 'errmsg' */
+ if (finished == 0)
+ png_crc_finish(png_ptr, length);
+
+ if (errmsg != NULL) /* else already output */
+ png_chunk_benign_error(png_ptr, errmsg);
+
+ return handled_error;
+}
+#else
+# define png_handle_iCCP NULL
+#endif /* READ_iCCP */
+
+#ifdef PNG_READ_sPLT_SUPPORTED
+static png_handle_result_code /* PRIVATE */
+png_handle_sPLT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+/* Note: this does not properly handle chunks that are > 64K under DOS */
+{
+ png_bytep entry_start, buffer;
+ png_sPLT_t new_palette;
+ png_sPLT_entryp pp;
+ png_uint_32 data_length;
+ int entry_size, i;
+ png_uint_32 skip = 0;
+ png_uint_32 dl;
+ size_t max_dl;
+
+ png_debug(1, "in png_handle_sPLT");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ if (png_ptr->user_chunk_cache_max != 0)
+ {
+ if (png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ return handled_error;
+ }
+
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ png_warning(png_ptr, "No space in chunk cache for sPLT");
+ png_crc_finish(png_ptr, length);
+ return handled_error;
+ }
+ }
+#endif
+
+ buffer = png_read_buffer(png_ptr, length+1);
+ if (buffer == NULL)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of memory");
+ return handled_error;
+ }
+
+
+ /* WARNING: this may break if size_t is less than 32 bits; it is assumed
+ * that the PNG_MAX_MALLOC_64K test is enabled in this case, but this is a
+ * potential breakage point if the types in pngconf.h aren't exactly right.
+ */
+ png_crc_read(png_ptr, buffer, length);
+
+ if (png_crc_finish(png_ptr, skip) != 0)
+ return handled_error;
+
+ buffer[length] = 0;
+
+ for (entry_start = buffer; *entry_start; entry_start++)
+ /* Empty loop to find end of name */ ;
+
+ ++entry_start;
+
+ /* A sample depth should follow the separator, and we should be on it */
+ if (length < 2U || entry_start > buffer + (length - 2U))
+ {
+ png_warning(png_ptr, "malformed sPLT chunk");
+ return handled_error;
+ }
+
+ new_palette.depth = *entry_start++;
+ entry_size = (new_palette.depth == 8 ? 6 : 10);
+ /* This must fit in a png_uint_32 because it is derived from the original
+ * chunk data length.
+ */
+ data_length = length - (png_uint_32)(entry_start - buffer);
+
+ /* Integrity-check the data length */
+ if ((data_length % (unsigned int)entry_size) != 0)
+ {
+ png_warning(png_ptr, "sPLT chunk has bad length");
+ return handled_error;
+ }
+
+ dl = (png_uint_32)(data_length / (unsigned int)entry_size);
+ max_dl = PNG_SIZE_MAX / (sizeof (png_sPLT_entry));
+
+ if (dl > max_dl)
+ {
+ png_warning(png_ptr, "sPLT chunk too long");
+ return handled_error;
+ }
+
+ new_palette.nentries = (png_int_32)(data_length / (unsigned int)entry_size);
+
+ new_palette.entries = (png_sPLT_entryp)png_malloc_warn(png_ptr,
+ (png_alloc_size_t) new_palette.nentries * (sizeof (png_sPLT_entry)));
+
+ if (new_palette.entries == NULL)
+ {
+ png_warning(png_ptr, "sPLT chunk requires too much memory");
+ return handled_error;
+ }
+
+ for (i = 0; i < new_palette.nentries; i++)
+ {
+ pp = new_palette.entries + i;
+
+ if (new_palette.depth == 8)
+ {
+ pp->red = *entry_start++;
+ pp->green = *entry_start++;
+ pp->blue = *entry_start++;
+ pp->alpha = *entry_start++;
+ }
+
+ else
+ {
+ pp->red = png_get_uint_16(entry_start); entry_start += 2;
+ pp->green = png_get_uint_16(entry_start); entry_start += 2;
+ pp->blue = png_get_uint_16(entry_start); entry_start += 2;
+ pp->alpha = png_get_uint_16(entry_start); entry_start += 2;
+ }
+
+ pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
+ }
+
+ /* Discard all chunk data except the name and stash that */
+ new_palette.name = (png_charp)buffer;
+
+ png_set_sPLT(png_ptr, info_ptr, &new_palette, 1);
+
+ png_free(png_ptr, new_palette.entries);
+ return handled_ok;
+}
+#else
+# define png_handle_sPLT NULL
+#endif /* READ_sPLT */
+
+#ifdef PNG_READ_tRNS_SUPPORTED
+static png_handle_result_code /* PRIVATE */
+png_handle_tRNS(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_byte readbuf[PNG_MAX_PALETTE_LENGTH];
+
+ png_debug(1, "in png_handle_tRNS");
+
+ if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ png_byte buf[2];
+
+ if (length != 2)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
+ return handled_error;
+ }
+
+ png_crc_read(png_ptr, buf, 2);
+ png_ptr->num_trans = 1;
+ png_ptr->trans_color.gray = png_get_uint_16(buf);
+ }
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ png_byte buf[6];
+
+ if (length != 6)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
+ return handled_error;
+ }
+
+ png_crc_read(png_ptr, buf, length);
+ png_ptr->num_trans = 1;
+ png_ptr->trans_color.red = png_get_uint_16(buf);
+ png_ptr->trans_color.green = png_get_uint_16(buf + 2);
+ png_ptr->trans_color.blue = png_get_uint_16(buf + 4);
+ }
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if ((png_ptr->mode & PNG_HAVE_PLTE) == 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
+ return handled_error;
+ }
+
+ if (length > (unsigned int) png_ptr->num_palette ||
+ length > (unsigned int) PNG_MAX_PALETTE_LENGTH ||
+ length == 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
+ return handled_error;
+ }
+
+ png_crc_read(png_ptr, readbuf, length);
+ png_ptr->num_trans = (png_uint_16)length;
+ }
+
+ else
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid with alpha channel");
+ return handled_error;
+ }
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ {
+ png_ptr->num_trans = 0;
+ return handled_error;
+ }
+
+ /* TODO: this is a horrible side effect in the palette case because the
+ * png_struct ends up with a pointer to the tRNS buffer owned by the
+ * png_info. Fix this.
+ */
+ png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans,
+ &(png_ptr->trans_color));
+ return handled_ok;
+}
+#else
+# define png_handle_tRNS NULL
+#endif
+
+#ifdef PNG_READ_bKGD_SUPPORTED
+static png_handle_result_code /* PRIVATE */
+png_handle_bKGD(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ unsigned int truelen;
+ png_byte buf[6];
+ png_color_16 background;
+
+ png_debug(1, "in png_handle_bKGD");
+
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if ((png_ptr->mode & PNG_HAVE_PLTE) == 0)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of place");
+ return handled_error;
+ }
+
+ truelen = 1;
+ }
+
+ else if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ truelen = 6;
+
+ else
+ truelen = 2;
+
+ if (length != truelen)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
+ return handled_error;
+ }
+
+ png_crc_read(png_ptr, buf, truelen);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return handled_error;
+
+ /* We convert the index value into RGB components so that we can allow
+ * arbitrary RGB values for background when we have transparency, and
+ * so it is easy to determine the RGB values of the background color
+ * from the info_ptr struct.
+ */
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ background.index = buf[0];
+
+ if (info_ptr != NULL && info_ptr->num_palette != 0)
+ {
+ if (buf[0] >= info_ptr->num_palette)
+ {
+ png_chunk_benign_error(png_ptr, "invalid index");
+ return handled_error;
+ }
+
+ background.red = (png_uint_16)png_ptr->palette[buf[0]].red;
+ background.green = (png_uint_16)png_ptr->palette[buf[0]].green;
+ background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue;
+ }
+
+ else
+ background.red = background.green = background.blue = 0;
+
+ background.gray = 0;
+ }
+
+ else if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) /* GRAY */
+ {
+ if (png_ptr->bit_depth <= 8)
+ {
+ if (buf[0] != 0 || buf[1] >= (unsigned int)(1 << png_ptr->bit_depth))
+ {
+ png_chunk_benign_error(png_ptr, "invalid gray level");
+ return handled_error;
+ }
+ }
+
+ background.index = 0;
+ background.red =
+ background.green =
+ background.blue =
+ background.gray = png_get_uint_16(buf);
+ }
+
+ else
+ {
+ if (png_ptr->bit_depth <= 8)
+ {
+ if (buf[0] != 0 || buf[2] != 0 || buf[4] != 0)
+ {
+ png_chunk_benign_error(png_ptr, "invalid color");
+ return handled_error;
+ }
+ }
+
+ background.index = 0;
+ background.red = png_get_uint_16(buf);
+ background.green = png_get_uint_16(buf + 2);
+ background.blue = png_get_uint_16(buf + 4);
+ background.gray = 0;
+ }
+
+ png_set_bKGD(png_ptr, info_ptr, &background);
+ return handled_ok;
+}
+#else
+# define png_handle_bKGD NULL
+#endif
+
+#ifdef PNG_READ_cICP_SUPPORTED
+static png_handle_result_code /* PRIVATE */
+png_handle_cICP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_byte buf[4];
+
+ png_debug(1, "in png_handle_cICP");
+
+ png_crc_read(png_ptr, buf, 4);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return handled_error;
+
+ png_set_cICP(png_ptr, info_ptr, buf[0], buf[1], buf[2], buf[3]);
+
+ /* We only use 'chromaticities' for RGB to gray */
+# ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ if (!png_has_chunk(png_ptr, mDCV))
+ {
+ /* TODO: png_ptr->chromaticities = chromaticities; */
+ }
+# endif /* READ_RGB_TO_GRAY */
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ /* PNGv3: chunk precedence for gamma is cICP, [iCCP], sRGB, gAMA. cICP is
+ * at the head so simply set the gamma if it can be determined. If not
+ * chunk_gamma remains unchanged; sRGB and gAMA handling check it for
+ * being zero.
+ */
+ /* TODO: set png_struct::chunk_gamma when possible */
+#endif /*READ_GAMMA*/
+
+ return handled_ok;
+ PNG_UNUSED(length)
+}
+#else
+# define png_handle_cICP NULL
+#endif
+
+#ifdef PNG_READ_cLLI_SUPPORTED
+static png_handle_result_code /* PRIVATE */
+png_handle_cLLI(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_byte buf[8];
+
+ png_debug(1, "in png_handle_cLLI");
+
+ png_crc_read(png_ptr, buf, 8);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return handled_error;
+
+ /* The error checking happens here, this puts it in just one place: */
+ png_set_cLLI_fixed(png_ptr, info_ptr, png_get_uint_32(buf),
+ png_get_uint_32(buf+4));
+ return handled_ok;
+ PNG_UNUSED(length)
+}
+#else
+# define png_handle_cLLI NULL
+#endif
+
+#ifdef PNG_READ_mDCV_SUPPORTED
+static png_handle_result_code /* PRIVATE */
+png_handle_mDCV(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_xy chromaticities;
+ png_byte buf[24];
+
+ png_debug(1, "in png_handle_mDCV");
+
+ png_crc_read(png_ptr, buf, 24);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return handled_error;
+
+ /* The error checking happens here, this puts it in just one place. The
+ * odd /50000 scaling factor makes it more difficult but the (x.y) values are
+ * only two bytes so a <<1 is safe.
+ *
+ * WARNING: the PNG specification defines the cHRM chunk to **start** with
+ * the white point (x,y). The W3C PNG v3 specification puts the white point
+ * **after* R,G,B. The x,y values in mDCV are also scaled by 50,000 and
+ * stored in just two bytes, whereas those in cHRM are scaled by 100,000 and
+ * stored in four bytes. This is very, very confusing. These APIs remove
+ * the confusion by copying the existing, well established, API.
+ */
+ chromaticities.redx = png_get_uint_16(buf+ 0U) << 1; /* red x */
+ chromaticities.redy = png_get_uint_16(buf+ 2U) << 1; /* red y */
+ chromaticities.greenx = png_get_uint_16(buf+ 4U) << 1; /* green x */
+ chromaticities.greeny = png_get_uint_16(buf+ 6U) << 1; /* green y */
+ chromaticities.bluex = png_get_uint_16(buf+ 8U) << 1; /* blue x */
+ chromaticities.bluey = png_get_uint_16(buf+10U) << 1; /* blue y */
+ chromaticities.whitex = png_get_uint_16(buf+12U) << 1; /* white x */
+ chromaticities.whitey = png_get_uint_16(buf+14U) << 1; /* white y */
+
+ png_set_mDCV_fixed(png_ptr, info_ptr,
+ chromaticities.whitex, chromaticities.whitey,
+ chromaticities.redx, chromaticities.redy,
+ chromaticities.greenx, chromaticities.greeny,
+ chromaticities.bluex, chromaticities.bluey,
+ png_get_uint_32(buf+16U), /* peak luminance */
+ png_get_uint_32(buf+20U));/* minimum perceivable luminance */
+
+ /* We only use 'chromaticities' for RGB to gray */
+# ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ png_ptr->chromaticities = chromaticities;
+# endif /* READ_RGB_TO_GRAY */
+
+ return handled_ok;
+ PNG_UNUSED(length)
+}
+#else
+# define png_handle_mDCV NULL
+#endif
+
+#ifdef PNG_READ_eXIf_SUPPORTED
+static png_handle_result_code /* PRIVATE */
+png_handle_eXIf(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_bytep buffer = NULL;
+
+ png_debug(1, "in png_handle_eXIf");
+
+ buffer = png_read_buffer(png_ptr, length);
+
+ if (buffer == NULL)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of memory");
+ return handled_error;
+ }
+
+ png_crc_read(png_ptr, buffer, length);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return handled_error;
+
+ /* PNGv3: the code used to check the byte order mark at the start for MM or
+ * II, however PNGv3 states that the the first 4 bytes should be checked.
+ * The caller ensures that there are four bytes available.
+ */
+ {
+ png_uint_32 header = png_get_uint_32(buffer);
+
+ /* These numbers are copied from the PNGv3 spec: */
+ if (header != 0x49492A00 && header != 0x4D4D002A)
+ {
+ png_chunk_benign_error(png_ptr, "invalid");
+ return handled_error;
+ }
+ }
+
+ png_set_eXIf_1(png_ptr, info_ptr, length, buffer);
+ return handled_ok;
+}
+#else
+# define png_handle_eXIf NULL
+#endif
+
+#ifdef PNG_READ_hIST_SUPPORTED
+static png_handle_result_code /* PRIVATE */
+png_handle_hIST(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ unsigned int num, i;
+ png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH];
+
+ png_debug(1, "in png_handle_hIST");
+
+ /* This cast is safe because the chunk definition limits the length to a
+ * maximum of 1024 bytes.
+ *
+ * TODO: maybe use png_uint_32 anyway, not unsigned int, to reduce the
+ * casts.
+ */
+ num = (unsigned int)length / 2 ;
+
+ if (length != num * 2 ||
+ num != (unsigned int)png_ptr->num_palette ||
+ num > (unsigned int)PNG_MAX_PALETTE_LENGTH)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "invalid");
+ return handled_error;
+ }
+
+ for (i = 0; i < num; i++)
+ {
+ png_byte buf[2];
+
+ png_crc_read(png_ptr, buf, 2);
+ readbuf[i] = png_get_uint_16(buf);
+ }
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return handled_error;
+
+ png_set_hIST(png_ptr, info_ptr, readbuf);
+ return handled_ok;
+}
+#else
+# define png_handle_hIST NULL
+#endif
+
+#ifdef PNG_READ_pHYs_SUPPORTED
+static png_handle_result_code /* PRIVATE */
+png_handle_pHYs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_byte buf[9];
+ png_uint_32 res_x, res_y;
+ int unit_type;
+
+ png_debug(1, "in png_handle_pHYs");
+
+ png_crc_read(png_ptr, buf, 9);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return handled_error;
+
+ res_x = png_get_uint_32(buf);
+ res_y = png_get_uint_32(buf + 4);
+ unit_type = buf[8];
+ png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type);
+ return handled_ok;
+ PNG_UNUSED(length)
+}
+#else
+# define png_handle_pHYs NULL
+#endif
+
+#ifdef PNG_READ_oFFs_SUPPORTED
+static png_handle_result_code /* PRIVATE */
+png_handle_oFFs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_byte buf[9];
+ png_int_32 offset_x, offset_y;
+ int unit_type;
+
+ png_debug(1, "in png_handle_oFFs");
+
+ png_crc_read(png_ptr, buf, 9);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return handled_error;
+
+ offset_x = png_get_int_32(buf);
+ offset_y = png_get_int_32(buf + 4);
+ unit_type = buf[8];
+ png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type);
+ return handled_ok;
+ PNG_UNUSED(length)
+}
+#else
+# define png_handle_oFFs NULL
+#endif
+
+#ifdef PNG_READ_pCAL_SUPPORTED
+/* Read the pCAL chunk (described in the PNG Extensions document) */
+static png_handle_result_code /* PRIVATE */
+png_handle_pCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_int_32 X0, X1;
+ png_byte type, nparams;
+ png_bytep buffer, buf, units, endptr;
+ png_charpp params;
+ int i;
+
+ png_debug(1, "in png_handle_pCAL");
+ png_debug1(2, "Allocating and reading pCAL chunk data (%u bytes)",
+ length + 1);
+
+ buffer = png_read_buffer(png_ptr, length+1);
+
+ if (buffer == NULL)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of memory");
+ return handled_error;
+ }
+
+ png_crc_read(png_ptr, buffer, length);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return handled_error;
+
+ buffer[length] = 0; /* Null terminate the last string */
+
+ png_debug(3, "Finding end of pCAL purpose string");
+ for (buf = buffer; *buf; buf++)
+ /* Empty loop */ ;
+
+ endptr = buffer + length;
+
+ /* We need to have at least 12 bytes after the purpose string
+ * in order to get the parameter information.
+ */
+ if (endptr - buf <= 12)
+ {
+ png_chunk_benign_error(png_ptr, "invalid");
+ return handled_error;
+ }
+
+ png_debug(3, "Reading pCAL X0, X1, type, nparams, and units");
+ X0 = png_get_int_32((png_bytep)buf+1);
+ X1 = png_get_int_32((png_bytep)buf+5);
+ type = buf[9];
+ nparams = buf[10];
+ units = buf + 11;
+
+ png_debug(3, "Checking pCAL equation type and number of parameters");
+ /* Check that we have the right number of parameters for known
+ * equation types.
+ */
+ if ((type == PNG_EQUATION_LINEAR && nparams != 2) ||
+ (type == PNG_EQUATION_BASE_E && nparams != 3) ||
+ (type == PNG_EQUATION_ARBITRARY && nparams != 3) ||
+ (type == PNG_EQUATION_HYPERBOLIC && nparams != 4))
+ {
+ png_chunk_benign_error(png_ptr, "invalid parameter count");
+ return handled_error;
+ }
+
+ else if (type >= PNG_EQUATION_LAST)
+ {
+ png_chunk_benign_error(png_ptr, "unrecognized equation type");
+ }
+
+ for (buf = units; *buf; buf++)
+ /* Empty loop to move past the units string. */ ;
+
+ png_debug(3, "Allocating pCAL parameters array");
+
+ params = png_voidcast(png_charpp, png_malloc_warn(png_ptr,
+ nparams * (sizeof (png_charp))));
+
+ if (params == NULL)
+ {
+ png_chunk_benign_error(png_ptr, "out of memory");
+ return handled_error;
+ }
+
+ /* Get pointers to the start of each parameter string. */
+ for (i = 0; i < nparams; i++)
+ {
+ buf++; /* Skip the null string terminator from previous parameter. */
+
+ png_debug1(3, "Reading pCAL parameter %d", i);
+
+ for (params[i] = (png_charp)buf; buf <= endptr && *buf != 0; buf++)
+ /* Empty loop to move past each parameter string */ ;
+
+ /* Make sure we haven't run out of data yet */
+ if (buf > endptr)
+ {
+ png_free(png_ptr, params);
+ png_chunk_benign_error(png_ptr, "invalid data");
+ return handled_error;
+ }
+ }
+
+ png_set_pCAL(png_ptr, info_ptr, (png_charp)buffer, X0, X1, type, nparams,
+ (png_charp)units, params);
+
+ /* TODO: BUG: png_set_pCAL calls png_chunk_report which, in this case, calls
+ * png_benign_error and that can error out.
+ *
+ * png_read_buffer needs to be allocated with space for both nparams and the
+ * parameter strings. Not hard to do.
+ */
+ png_free(png_ptr, params);
+ return handled_ok;
+}
+#else
+# define png_handle_pCAL NULL
+#endif
+
+#ifdef PNG_READ_sCAL_SUPPORTED
+/* Read the sCAL chunk */
+static png_handle_result_code /* PRIVATE */
+png_handle_sCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_bytep buffer;
+ size_t i;
+ int state;
+
+ png_debug(1, "in png_handle_sCAL");
+ png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)",
+ length + 1);
+
+ buffer = png_read_buffer(png_ptr, length+1);
+
+ if (buffer == NULL)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of memory");
+ return handled_error;
+ }
+
+ png_crc_read(png_ptr, buffer, length);
+ buffer[length] = 0; /* Null terminate the last string */
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return handled_error;
+
+ /* Validate the unit. */
+ if (buffer[0] != 1 && buffer[0] != 2)
+ {
+ png_chunk_benign_error(png_ptr, "invalid unit");
+ return handled_error;
+ }
+
+ /* Validate the ASCII numbers, need two ASCII numbers separated by
+ * a '\0' and they need to fit exactly in the chunk data.
+ */
+ i = 1;
+ state = 0;
+
+ if (png_check_fp_number((png_const_charp)buffer, length, &state, &i) == 0 ||
+ i >= length || buffer[i++] != 0)
+ png_chunk_benign_error(png_ptr, "bad width format");
+
+ else if (PNG_FP_IS_POSITIVE(state) == 0)
+ png_chunk_benign_error(png_ptr, "non-positive width");
+
+ else
+ {
+ size_t heighti = i;
+
+ state = 0;
+ if (png_check_fp_number((png_const_charp)buffer, length,
+ &state, &i) == 0 || i != length)
+ png_chunk_benign_error(png_ptr, "bad height format");
+
+ else if (PNG_FP_IS_POSITIVE(state) == 0)
+ png_chunk_benign_error(png_ptr, "non-positive height");
+
+ else
+ {
+ /* This is the (only) success case. */
+ png_set_sCAL_s(png_ptr, info_ptr, buffer[0],
+ (png_charp)buffer+1, (png_charp)buffer+heighti);
+ return handled_ok;
+ }
+ }
+
+ return handled_error;
+}
+#else
+# define png_handle_sCAL NULL
+#endif
+
+#ifdef PNG_READ_tIME_SUPPORTED
+static png_handle_result_code /* PRIVATE */
+png_handle_tIME(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_byte buf[7];
+ png_time mod_time;
+
+ png_debug(1, "in png_handle_tIME");
+
+ /* TODO: what is this doing here? It should be happened in pngread.c and
+ * pngpread.c, although it could be moved to png_handle_chunk below and
+ * thereby avoid some code duplication.
+ */
+ if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+ png_crc_read(png_ptr, buf, 7);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return handled_error;
+
+ mod_time.second = buf[6];
+ mod_time.minute = buf[5];
+ mod_time.hour = buf[4];
+ mod_time.day = buf[3];
+ mod_time.month = buf[2];
+ mod_time.year = png_get_uint_16(buf);
+
+ png_set_tIME(png_ptr, info_ptr, &mod_time);
+ return handled_ok;
+ PNG_UNUSED(length)
+}
+#else
+# define png_handle_tIME NULL
+#endif
+
+#ifdef PNG_READ_tEXt_SUPPORTED
+/* Note: this does not properly handle chunks that are > 64K under DOS */
+static png_handle_result_code /* PRIVATE */
+png_handle_tEXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_text text_info;
+ png_bytep buffer;
+ png_charp key;
+ png_charp text;
+ png_uint_32 skip = 0;
+
+ png_debug(1, "in png_handle_tEXt");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ if (png_ptr->user_chunk_cache_max != 0)
+ {
+ if (png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ return handled_error;
+ }
+
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "no space in chunk cache");
+ return handled_error;
+ }
+ }
+#endif
+
+ /* TODO: this doesn't work and shouldn't be necessary. */
+ if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+ buffer = png_read_buffer(png_ptr, length+1);
+
+ if (buffer == NULL)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of memory");
+ return handled_error;
+ }
+
+ png_crc_read(png_ptr, buffer, length);
+
+ if (png_crc_finish(png_ptr, skip) != 0)
+ return handled_error;
+
+ key = (png_charp)buffer;
+ key[length] = 0;
+
+ for (text = key; *text; text++)
+ /* Empty loop to find end of key */ ;
+
+ if (text != key + length)
+ text++;
+
+ text_info.compression = PNG_TEXT_COMPRESSION_NONE;
+ text_info.key = key;
+ text_info.lang = NULL;
+ text_info.lang_key = NULL;
+ text_info.itxt_length = 0;
+ text_info.text = text;
+ text_info.text_length = strlen(text);
+
+ if (png_set_text_2(png_ptr, info_ptr, &text_info, 1) == 0)
+ return handled_ok;
+
+ png_chunk_benign_error(png_ptr, "out of memory");
+ return handled_error;
+}
+#else
+# define png_handle_tEXt NULL
+#endif
+
+#ifdef PNG_READ_zTXt_SUPPORTED
+/* Note: this does not correctly handle chunks that are > 64K under DOS */
+static png_handle_result_code /* PRIVATE */
+png_handle_zTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_const_charp errmsg = NULL;
+ png_bytep buffer;
+ png_uint_32 keyword_length;
+
+ png_debug(1, "in png_handle_zTXt");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ if (png_ptr->user_chunk_cache_max != 0)
+ {
+ if (png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ return handled_error;
+ }
+
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "no space in chunk cache");
+ return handled_error;
+ }
+ }
+#endif
+
+ /* TODO: should not be necessary. */
+ if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+ /* Note, "length" is sufficient here; we won't be adding
+ * a null terminator later. The limit check in png_handle_chunk should be
+ * sufficient.
+ */
+ buffer = png_read_buffer(png_ptr, length);
+
+ if (buffer == NULL)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of memory");
+ return handled_error;
+ }
+
+ png_crc_read(png_ptr, buffer, length);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return handled_error;
+
+ /* TODO: also check that the keyword contents match the spec! */
+ for (keyword_length = 0;
+ keyword_length < length && buffer[keyword_length] != 0;
+ ++keyword_length)
+ /* Empty loop to find end of name */ ;
+
+ if (keyword_length > 79 || keyword_length < 1)
+ errmsg = "bad keyword";
+
+ /* zTXt must have some LZ data after the keyword, although it may expand to
+ * zero bytes; we need a '\0' at the end of the keyword, the compression type
+ * then the LZ data:
+ */
+ else if (keyword_length + 3 > length)
+ errmsg = "truncated";
+
+ else if (buffer[keyword_length+1] != PNG_COMPRESSION_TYPE_BASE)
+ errmsg = "unknown compression type";
+
+ else
+ {
+ png_alloc_size_t uncompressed_length = PNG_SIZE_MAX;
+
+ /* TODO: at present png_decompress_chunk imposes a single application
+ * level memory limit, this should be split to different values for iCCP
+ * and text chunks.
+ */
+ if (png_decompress_chunk(png_ptr, length, keyword_length+2,
+ &uncompressed_length, 1/*terminate*/) == Z_STREAM_END)
+ {
+ png_text text;
+
+ if (png_ptr->read_buffer == NULL)
+ errmsg="Read failure in png_handle_zTXt";
+ else
+ {
+ /* It worked; png_ptr->read_buffer now looks like a tEXt chunk
+ * except for the extra compression type byte and the fact that
+ * it isn't necessarily '\0' terminated.
+ */
+ buffer = png_ptr->read_buffer;
+ buffer[uncompressed_length+(keyword_length+2)] = 0;
+
+ text.compression = PNG_TEXT_COMPRESSION_zTXt;
+ text.key = (png_charp)buffer;
+ text.text = (png_charp)(buffer + keyword_length+2);
+ text.text_length = uncompressed_length;
+ text.itxt_length = 0;
+ text.lang = NULL;
+ text.lang_key = NULL;
+
+ if (png_set_text_2(png_ptr, info_ptr, &text, 1) == 0)
+ return handled_ok;
+
+ errmsg = "out of memory";
+ }
+ }
+
+ else
+ errmsg = png_ptr->zstream.msg;
+ }
+
+ png_chunk_benign_error(png_ptr, errmsg);
+ return handled_error;
+}
+#else
+# define png_handle_zTXt NULL
+#endif
+
+#ifdef PNG_READ_iTXt_SUPPORTED
+/* Note: this does not correctly handle chunks that are > 64K under DOS */
+static png_handle_result_code /* PRIVATE */
+png_handle_iTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ png_const_charp errmsg = NULL;
+ png_bytep buffer;
+ png_uint_32 prefix_length;
+
+ png_debug(1, "in png_handle_iTXt");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ if (png_ptr->user_chunk_cache_max != 0)
+ {
+ if (png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ return handled_error;
+ }
+
+ if (--png_ptr->user_chunk_cache_max == 1)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "no space in chunk cache");
+ return handled_error;
+ }
+ }
+#endif
+
+ /* TODO: should not be necessary. */
+ if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+ buffer = png_read_buffer(png_ptr, length+1);
+
+ if (buffer == NULL)
+ {
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "out of memory");
+ return handled_error;
+ }
+
+ png_crc_read(png_ptr, buffer, length);
+
+ if (png_crc_finish(png_ptr, 0) != 0)
+ return handled_error;
+
+ /* First the keyword. */
+ for (prefix_length=0;
+ prefix_length < length && buffer[prefix_length] != 0;
+ ++prefix_length)
+ /* Empty loop */ ;
+
+ /* Perform a basic check on the keyword length here. */
+ if (prefix_length > 79 || prefix_length < 1)
+ errmsg = "bad keyword";
+
+ /* Expect keyword, compression flag, compression type, language, translated
+ * keyword (both may be empty but are 0 terminated) then the text, which may
+ * be empty.
+ */
+ else if (prefix_length + 5 > length)
+ errmsg = "truncated";
+
+ else if (buffer[prefix_length+1] == 0 ||
+ (buffer[prefix_length+1] == 1 &&
+ buffer[prefix_length+2] == PNG_COMPRESSION_TYPE_BASE))
+ {
+ int compressed = buffer[prefix_length+1] != 0;
+ png_uint_32 language_offset, translated_keyword_offset;
+ png_alloc_size_t uncompressed_length = 0;
+
+ /* Now the language tag */
+ prefix_length += 3;
+ language_offset = prefix_length;
+
+ for (; prefix_length < length && buffer[prefix_length] != 0;
+ ++prefix_length)
+ /* Empty loop */ ;
+
+ /* WARNING: the length may be invalid here, this is checked below. */
+ translated_keyword_offset = ++prefix_length;
+
+ for (; prefix_length < length && buffer[prefix_length] != 0;
+ ++prefix_length)
+ /* Empty loop */ ;
+
+ /* prefix_length should now be at the trailing '\0' of the translated
+ * keyword, but it may already be over the end. None of this arithmetic
+ * can overflow because chunks are at most 2^31 bytes long, but on 16-bit
+ * systems the available allocation may overflow.
+ */
+ ++prefix_length;
+
+ if (compressed == 0 && prefix_length <= length)
+ uncompressed_length = length - prefix_length;
+
+ else if (compressed != 0 && prefix_length < length)
+ {
+ uncompressed_length = PNG_SIZE_MAX;
+
+ /* TODO: at present png_decompress_chunk imposes a single application
+ * level memory limit, this should be split to different values for
+ * iCCP and text chunks.
+ */
+ if (png_decompress_chunk(png_ptr, length, prefix_length,
+ &uncompressed_length, 1/*terminate*/) == Z_STREAM_END)
+ buffer = png_ptr->read_buffer;
+
+ else
+ errmsg = png_ptr->zstream.msg;
+ }
+
+ else
+ errmsg = "truncated";
+
+ if (errmsg == NULL)
+ {
+ png_text text;
+
+ buffer[uncompressed_length+prefix_length] = 0;
+
+ if (compressed == 0)
+ text.compression = PNG_ITXT_COMPRESSION_NONE;
+
+ else
+ text.compression = PNG_ITXT_COMPRESSION_zTXt;
+
+ text.key = (png_charp)buffer;
+ text.lang = (png_charp)buffer + language_offset;
+ text.lang_key = (png_charp)buffer + translated_keyword_offset;
+ text.text = (png_charp)buffer + prefix_length;
+ text.text_length = 0;
+ text.itxt_length = uncompressed_length;
+
+ if (png_set_text_2(png_ptr, info_ptr, &text, 1) == 0)
+ return handled_ok;
+
+ errmsg = "out of memory";
+ }
+ }
+
+ else
+ errmsg = "bad compression info";
+
+ if (errmsg != NULL)
+ png_chunk_benign_error(png_ptr, errmsg);
+ return handled_error;
+}
+#else
+# define png_handle_iTXt NULL
+#endif
+
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+/* Utility function for png_handle_unknown; set up png_ptr::unknown_chunk */
+static int
+png_cache_unknown_chunk(png_structrp png_ptr, png_uint_32 length)
+{
+ const png_alloc_size_t limit = png_chunk_max(png_ptr);
+
+ if (png_ptr->unknown_chunk.data != NULL)
+ {
+ png_free(png_ptr, png_ptr->unknown_chunk.data);
+ png_ptr->unknown_chunk.data = NULL;
+ }
+
+ if (length <= limit)
+ {
+ PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name);
+ /* The following is safe because of the PNG_SIZE_MAX init above */
+ png_ptr->unknown_chunk.size = (size_t)length/*SAFE*/;
+ /* 'mode' is a flag array, only the bottom four bits matter here */
+ png_ptr->unknown_chunk.location = (png_byte)png_ptr->mode/*SAFE*/;
+
+ if (length == 0)
+ png_ptr->unknown_chunk.data = NULL;
+
+ else
+ {
+ /* Do a 'warn' here - it is handled below. */
+ png_ptr->unknown_chunk.data = png_voidcast(png_bytep,
+ png_malloc_warn(png_ptr, length));
+ }
+ }
+
+ if (png_ptr->unknown_chunk.data == NULL && length > 0)
+ {
+ /* This is benign because we clean up correctly */
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, "unknown chunk exceeds memory limits");
+ return 0;
+ }
+
+ else
+ {
+ if (length > 0)
+ png_crc_read(png_ptr, png_ptr->unknown_chunk.data, length);
+ png_crc_finish(png_ptr, 0);
+ return 1;
+ }
+}
+#endif /* READ_UNKNOWN_CHUNKS */
+
+/* Handle an unknown, or known but disabled, chunk */
+png_handle_result_code /*PRIVATE*/
+png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
+ png_uint_32 length, int keep)
+{
+ png_handle_result_code handled = handled_discarded; /* the default */
+
+ png_debug(1, "in png_handle_unknown");
+
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+ /* NOTE: this code is based on the code in libpng-1.4.12 except for fixing
+ * the bug which meant that setting a non-default behavior for a specific
+ * chunk would be ignored (the default was always used unless a user
+ * callback was installed).
+ *
+ * 'keep' is the value from the png_chunk_unknown_handling, the setting for
+ * this specific chunk_name, if PNG_HANDLE_AS_UNKNOWN_SUPPORTED, if not it
+ * will always be PNG_HANDLE_CHUNK_AS_DEFAULT and it needs to be set here.
+ * This is just an optimization to avoid multiple calls to the lookup
+ * function.
+ */
+# ifndef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+# ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+ keep = png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name);
+# endif
+# endif
+
+ /* One of the following methods will read the chunk or skip it (at least one
+ * of these is always defined because this is the only way to switch on
+ * PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+ */
+# ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+ /* The user callback takes precedence over the chunk keep value, but the
+ * keep value is still required to validate a save of a critical chunk.
+ */
+ if (png_ptr->read_user_chunk_fn != NULL)
+ {
+ if (png_cache_unknown_chunk(png_ptr, length) != 0)
+ {
+ /* Callback to user unknown chunk handler */
+ int ret = (*(png_ptr->read_user_chunk_fn))(png_ptr,
+ &png_ptr->unknown_chunk);
+
+ /* ret is:
+ * negative: An error occurred; png_chunk_error will be called.
+ * zero: The chunk was not handled, the chunk will be discarded
+ * unless png_set_keep_unknown_chunks has been used to set
+ * a 'keep' behavior for this particular chunk, in which
+ * case that will be used. A critical chunk will cause an
+ * error at this point unless it is to be saved.
+ * positive: The chunk was handled, libpng will ignore/discard it.
+ */
+ if (ret < 0) /* handled_error */
+ png_chunk_error(png_ptr, "error in user chunk");
+
+ else if (ret == 0)
+ {
+ /* If the keep value is 'default' or 'never' override it, but
+ * still error out on critical chunks unless the keep value is
+ * 'always' While this is weird it is the behavior in 1.4.12.
+ * A possible improvement would be to obey the value set for the
+ * chunk, but this would be an API change that would probably
+ * damage some applications.
+ *
+ * The png_app_warning below catches the case that matters, where
+ * the application has not set specific save or ignore for this
+ * chunk or global save or ignore.
+ */
+ if (keep < PNG_HANDLE_CHUNK_IF_SAFE)
+ {
+# ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+ if (png_ptr->unknown_default < PNG_HANDLE_CHUNK_IF_SAFE)
+ {
+ png_chunk_warning(png_ptr, "Saving unknown chunk:");
+ png_app_warning(png_ptr,
+ "forcing save of an unhandled chunk;"
+ " please call png_set_keep_unknown_chunks");
+ /* with keep = PNG_HANDLE_CHUNK_IF_SAFE */
+ }
+# endif
+ keep = PNG_HANDLE_CHUNK_IF_SAFE;
+ }
+ }
+
+ else /* chunk was handled */
+ {
+ handled = handled_ok;
+ /* Critical chunks can be safely discarded at this point. */
+ keep = PNG_HANDLE_CHUNK_NEVER;
+ }
+ }
+
+ else
+ keep = PNG_HANDLE_CHUNK_NEVER; /* insufficient memory */
+ }
+
+ else
+ /* Use the SAVE_UNKNOWN_CHUNKS code or skip the chunk */
+# endif /* READ_USER_CHUNKS */
+
+# ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
+ {
+ /* keep is currently just the per-chunk setting, if there was no
+ * setting change it to the global default now (not that this may
+ * still be AS_DEFAULT) then obtain the cache of the chunk if required,
+ * if not simply skip the chunk.
+ */
+ if (keep == PNG_HANDLE_CHUNK_AS_DEFAULT)
+ keep = png_ptr->unknown_default;
+
+ if (keep == PNG_HANDLE_CHUNK_ALWAYS ||
+ (keep == PNG_HANDLE_CHUNK_IF_SAFE &&
+ PNG_CHUNK_ANCILLARY(png_ptr->chunk_name)))
+ {
+ if (png_cache_unknown_chunk(png_ptr, length) == 0)
+ keep = PNG_HANDLE_CHUNK_NEVER;
+ }
+
+ else
+ png_crc_finish(png_ptr, length);
+ }
+# else
+# ifndef PNG_READ_USER_CHUNKS_SUPPORTED
+# error no method to support READ_UNKNOWN_CHUNKS
+# endif
+
+ {
+ /* If here there is no read callback pointer set and no support is
+ * compiled in to just save the unknown chunks, so simply skip this
+ * chunk. If 'keep' is something other than AS_DEFAULT or NEVER then
+ * the app has erroneously asked for unknown chunk saving when there
+ * is no support.
+ */
+ if (keep > PNG_HANDLE_CHUNK_NEVER)
+ png_app_error(png_ptr, "no unknown chunk support available");
+
+ png_crc_finish(png_ptr, length);
+ }
+# endif
+
+# ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+ /* Now store the chunk in the chunk list if appropriate, and if the limits
+ * permit it.
+ */
+ if (keep == PNG_HANDLE_CHUNK_ALWAYS ||
+ (keep == PNG_HANDLE_CHUNK_IF_SAFE &&
+ PNG_CHUNK_ANCILLARY(png_ptr->chunk_name)))
+ {
+# ifdef PNG_USER_LIMITS_SUPPORTED
+ switch (png_ptr->user_chunk_cache_max)
+ {
+ case 2:
+ png_ptr->user_chunk_cache_max = 1;
+ png_chunk_benign_error(png_ptr, "no space in chunk cache");
+ /* FALLTHROUGH */
+ case 1:
+ /* NOTE: prior to 1.6.0 this case resulted in an unknown critical
+ * chunk being skipped, now there will be a hard error below.
+ */
+ break;
+
+ default: /* not at limit */
+ --(png_ptr->user_chunk_cache_max);
+ /* FALLTHROUGH */
+ case 0: /* no limit */
+# endif /* USER_LIMITS */
+ /* Here when the limit isn't reached or when limits are compiled
+ * out; store the chunk.
+ */
+ png_set_unknown_chunks(png_ptr, info_ptr,
+ &png_ptr->unknown_chunk, 1);
+ handled = handled_saved;
+# ifdef PNG_USER_LIMITS_SUPPORTED
+ break;
+ }
+# endif
+ }
+# else /* no store support: the chunk must be handled by the user callback */
+ PNG_UNUSED(info_ptr)
+# endif
+
+ /* Regardless of the error handling below the cached data (if any) can be
+ * freed now. Notice that the data is not freed if there is a png_error, but
+ * it will be freed by destroy_read_struct.
+ */
+ if (png_ptr->unknown_chunk.data != NULL)
+ png_free(png_ptr, png_ptr->unknown_chunk.data);
+ png_ptr->unknown_chunk.data = NULL;
+
+#else /* !PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */
+ /* There is no support to read an unknown chunk, so just skip it. */
+ png_crc_finish(png_ptr, length);
+ PNG_UNUSED(info_ptr)
+ PNG_UNUSED(keep)
+#endif /* !READ_UNKNOWN_CHUNKS */
+
+ /* Check for unhandled critical chunks */
+ if (handled < handled_saved && PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
+ png_chunk_error(png_ptr, "unhandled critical chunk");
+
+ return handled;
+}
+
+/* APNG handling: the minimal implementation of APNG handling in libpng 1.6
+ * requires that those significant applications which already handle APNG not
+ * get hosed. To do this ensure the code here will have to ensure than APNG
+ * data by default (at least in 1.6) gets stored in the unknown chunk list.
+ * Maybe this can be relaxed in a few years but at present it's just the only
+ * safe way.
+ *
+ * ATM just cause unknown handling for all three chunks:
+ */
+#define png_handle_acTL NULL
+#define png_handle_fcTL NULL
+#define png_handle_fdAT NULL
+
+/*
+ * 1.6.47: This is the new table driven interface to all the chunk handling.
+ *
+ * The table describes the PNG standard rules for **reading** known chunks -
+ * every chunk which has an entry in PNG_KNOWN_CHUNKS. The table contains an
+ * entry for each PNG_INDEX_cHNK describing the rules.
+ *
+ * In this initial version the only information in the entry is the
+ * png_handle_cHNK function for the chunk in question. When chunk support is
+ * compiled out the entry will be NULL.
+ */
+static const struct
+{
+ png_handle_result_code (*handler)(
+ png_structrp, png_inforp, png_uint_32 length);
+ /* A chunk-specific 'handler', NULL if the chunk is not supported in this
+ * build.
+ */
+
+ /* Crushing these values helps on modern 32-bit architectures because the
+ * pointer and the following bit fields both end up requiring 32 bits.
+ * Typically this will halve the table size. On 64-bit architectures the
+ * table entries will typically be 8 bytes.
+ */
+ png_uint_32 max_length :12; /* Length min, max in bytes */
+ png_uint_32 min_length :8;
+ /* Length errors on critical chunks have special handling to preserve the
+ * existing behaviour in libpng 1.6. Anciallary chunks are checked below
+ * and produce a 'benign' error.
+ */
+ png_uint_32 pos_before :4; /* PNG_HAVE_ values chunk must precede */
+ png_uint_32 pos_after :4; /* PNG_HAVE_ values chunk must follow */
+ /* NOTE: PLTE, tRNS and bKGD require special handling which depends on
+ * the colour type of the base image.
+ */
+ png_uint_32 multiple :1; /* Multiple occurences permitted */
+ /* This is enabled for PLTE because PLTE may, in practice, be optional */
+}
+read_chunks[PNG_INDEX_unknown] =
+{
+ /* Definitions as above but done indirectly by #define so that
+ * PNG_KNOWN_CHUNKS can be used safely to build the table in order.
+ *
+ * Each CDcHNK definition lists the values for the parameters **after**
+ * the first, 'handler', function. 'handler' is NULL when the chunk has no
+ * compiled in support.
+ */
+# define NoCheck 0x801U /* Do not check the maximum length */
+# define Limit 0x802U /* Limit to png_chunk_max bytes */
+# define LKMin 3U+LZ77Min /* Minimum length of keyword+LZ77 */
+
+#define hIHDR PNG_HAVE_IHDR
+#define hPLTE PNG_HAVE_PLTE
+#define hIDAT PNG_HAVE_IDAT
+ /* For the two chunks, tRNS and bKGD which can occur in PNGs without a PLTE
+ * but must occur after the PLTE use this and put the check in the handler
+ * routine for colour mapped images were PLTE is required. Also put a check
+ * in PLTE for other image types to drop the PLTE if tRNS or bKGD have been
+ * seen.
+ */
+#define hCOL (PNG_HAVE_PLTE|PNG_HAVE_IDAT)
+ /* Used for the decoding chunks which must be before PLTE. */
+#define aIDAT PNG_AFTER_IDAT
+
+ /* Chunks from W3C PNG v3: */
+ /* cHNK max_len, min, before, after, multiple */
+# define CDIHDR 13U, 13U, hIHDR, 0, 0
+# define CDPLTE NoCheck, 0U, 0, hIHDR, 1
+ /* PLTE errors are only critical for colour-map images, consequently the
+ * hander does all the checks.
+ */
+# define CDIDAT NoCheck, 0U, aIDAT, hIHDR, 1
+# define CDIEND NoCheck, 0U, 0, aIDAT, 0
+ /* Historically data was allowed in IEND */
+# define CDtRNS 256U, 0U, hIDAT, hIHDR, 0
+# define CDcHRM 32U, 32U, hCOL, hIHDR, 0
+# define CDgAMA 4U, 4U, hCOL, hIHDR, 0
+# define CDiCCP NoCheck, LKMin, hCOL, hIHDR, 0
+# define CDsBIT 4U, 1U, hCOL, hIHDR, 0
+# define CDsRGB 1U, 1U, hCOL, hIHDR, 0
+# define CDcICP 4U, 4U, hCOL, hIHDR, 0
+# define CDmDCV 24U, 24U, hCOL, hIHDR, 0
+# define CDeXIf Limit, 4U, 0, hIHDR, 0
+# define CDcLLI 8U, 8U, hCOL, hIHDR, 0
+# define CDtEXt NoCheck, 2U, 0, hIHDR, 1
+ /* Allocates 'length+1'; checked in the handler */
+# define CDzTXt Limit, LKMin, 0, hIHDR, 1
+# define CDiTXt NoCheck, 6U, 0, hIHDR, 1
+ /* Allocates 'length+1'; checked in the handler */
+# define CDbKGD 6U, 1U, hIDAT, hIHDR, 0
+# define CDhIST 1024U, 0U, hPLTE, hIHDR, 0
+# define CDpHYs 9U, 9U, hIDAT, hIHDR, 0
+# define CDsPLT NoCheck, 3U, hIDAT, hIHDR, 1
+ /* Allocates 'length+1'; checked in the handler */
+# define CDtIME 7U, 7U, 0, hIHDR, 0
+# define CDacTL 8U, 8U, hIDAT, hIHDR, 0
+# define CDfcTL 25U, 26U, 0, hIHDR, 1
+# define CDfdAT Limit, 4U, hIDAT, hIHDR, 1
+ /* Supported chunks from PNG extensions 1.5.0, NYI so limit */
+# define CDoFFs 9U, 9U, hIDAT, hIHDR, 0
+# define CDpCAL NoCheck, 14U, hIDAT, hIHDR, 0
+ /* Allocates 'length+1'; checked in the handler */
+# define CDsCAL Limit, 4U, hIDAT, hIHDR, 0
+ /* Allocates 'length+1'; checked in the handler */
+
+# define PNG_CHUNK(cHNK, index) { png_handle_ ## cHNK, CD ## cHNK },
+ PNG_KNOWN_CHUNKS
+# undef PNG_CHUNK
+};
+
+
+static png_index
+png_chunk_index_from_name(png_uint_32 chunk_name)
+{
+ /* For chunk png_cHNK return PNG_INDEX_cHNK. Return PNG_INDEX_unknown if
+ * chunk_name is not known. Notice that in a particular build "known" does
+ * not necessarily mean "supported", although the inverse applies.
+ */
+ switch (chunk_name)
+ {
+# define PNG_CHUNK(cHNK, index)\
+ case png_ ## cHNK: return PNG_INDEX_ ## cHNK; /* == index */
+
+ PNG_KNOWN_CHUNKS
+
+# undef PNG_CHUNK
+
+ default: return PNG_INDEX_unknown;
+ }
+}
+
+png_handle_result_code /*PRIVATE*/
+png_handle_chunk(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+ /* CSE: these things don't change, these autos are just to save typing and
+ * make the code more clear.
+ */
+ const png_uint_32 chunk_name = png_ptr->chunk_name;
+ const png_index chunk_index = png_chunk_index_from_name(chunk_name);
+
+ png_handle_result_code handled = handled_error;
+ png_const_charp errmsg = NULL;
+
+ /* Is this a known chunk? If not there are no checks performed here;
+ * png_handle_unknown does the correct checks. This means that the values
+ * for known but unsupported chunks in the above table are not used here
+ * however the chunks_seen fields in png_struct are still set.
+ */
+ if (chunk_index == PNG_INDEX_unknown ||
+ read_chunks[chunk_index].handler == NULL)
+ {
+ handled = png_handle_unknown(
+ png_ptr, info_ptr, length, PNG_HANDLE_CHUNK_AS_DEFAULT);
+ }
+
+ /* First check the position. The first check is historical; the stream must
+ * start with IHDR and anything else causes libpng to give up immediately.
+ */
+ else if (chunk_index != PNG_INDEX_IHDR &&
+ (png_ptr->mode & PNG_HAVE_IHDR) == 0)
+ png_chunk_error(png_ptr, "missing IHDR"); /* NORETURN */
+
+ /* Before all the pos_before chunks, after all the pos_after chunks. */
+ else if (((png_ptr->mode & read_chunks[chunk_index].pos_before) != 0) ||
+ ((png_ptr->mode & read_chunks[chunk_index].pos_after) !=
+ read_chunks[chunk_index].pos_after))
+ {
+ errmsg = "out of place";
+ }
+
+ /* Now check for duplicates: duplicated critical chunks also produce a
+ * full error.
+ */
+ else if (read_chunks[chunk_index].multiple == 0 &&
+ png_file_has_chunk(png_ptr, chunk_index))
+ {
+ errmsg = "duplicate";
+ }
+
+ else if (length < read_chunks[chunk_index].min_length)
+ errmsg = "too short";
+ else
+ {
+ /* NOTE: apart from IHDR the critical chunks (PLTE, IDAT and IEND) are set
+ * up above not to do any length checks.
+ *
+ * The png_chunk_max check ensures that the variable length chunks are
+ * always checked at this point for being within the system allocation
+ * limits.
+ */
+ unsigned max_length = read_chunks[chunk_index].max_length;
+
+ switch (max_length)
+ {
+ case Limit:
+ /* png_read_chunk_header has already png_error'ed chunks with a
+ * length exceeding the 31-bit PNG limit, so just check the memory
+ * limit:
+ */
+ if (length <= png_chunk_max(png_ptr))
+ goto MeetsLimit;
+
+ errmsg = "length exceeds libpng limit";
+ break;
+
+ default:
+ if (length <= max_length)
+ goto MeetsLimit;
+
+ errmsg = "too long";
+ break;
+
+ case NoCheck:
+ MeetsLimit:
+ handled = read_chunks[chunk_index].handler(
+ png_ptr, info_ptr, length);
+ break;
+ }
+ }
+
+ /* If there was an error or the chunk was simply skipped it is not counted as
+ * 'seen'.
+ */
+ if (errmsg != NULL)
+ {
+ if (PNG_CHUNK_CRITICAL(chunk_name)) /* stop immediately */
+ png_chunk_error(png_ptr, errmsg);
+ else /* ancillary chunk */
+ {
+ /* The chunk data is skipped: */
+ png_crc_finish(png_ptr, length);
+ png_chunk_benign_error(png_ptr, errmsg);
+ }
+ }
+
+ else if (handled >= handled_saved)
+ {
+ if (chunk_index != PNG_INDEX_unknown)
+ png_file_add_chunk(png_ptr, chunk_index);
+ }
+
+ return handled;
+}
+
+/* Combines the row recently read in with the existing pixels in the row. This
+ * routine takes care of alpha and transparency if requested. This routine also
+ * handles the two methods of progressive display of interlaced images,
+ * depending on the 'display' value; if 'display' is true then the whole row
+ * (dp) is filled from the start by replicating the available pixels. If
+ * 'display' is false only those pixels present in the pass are filled in.
+ */
+void /* PRIVATE */
+png_combine_row(png_const_structrp png_ptr, png_bytep dp, int display)
+{
+ unsigned int pixel_depth = png_ptr->transformed_pixel_depth;
+ png_const_bytep sp = png_ptr->row_buf + 1;
+ png_alloc_size_t row_width = png_ptr->width;
+ unsigned int pass = png_ptr->pass;
+ png_bytep end_ptr = 0;
+ png_byte end_byte = 0;
+ unsigned int end_mask;
+
+ png_debug(1, "in png_combine_row");
+
+ /* Added in 1.5.6: it should not be possible to enter this routine until at
+ * least one row has been read from the PNG data and transformed.
+ */
+ if (pixel_depth == 0)
+ png_error(png_ptr, "internal row logic error");
+
+ /* Added in 1.5.4: the pixel depth should match the information returned by
+ * any call to png_read_update_info at this point. Do not continue if we got
+ * this wrong.
+ */
+ if (png_ptr->info_rowbytes != 0 && png_ptr->info_rowbytes !=
+ PNG_ROWBYTES(pixel_depth, row_width))
+ png_error(png_ptr, "internal row size calculation error");
+
+ /* Don't expect this to ever happen: */
+ if (row_width == 0)
+ png_error(png_ptr, "internal row width error");
+
+ /* Preserve the last byte in cases where only part of it will be overwritten,
+ * the multiply below may overflow, we don't care because ANSI-C guarantees
+ * we get the low bits.
+ */
+ end_mask = (pixel_depth * row_width) & 7;
+ if (end_mask != 0)
+ {
+ /* end_ptr == NULL is a flag to say do nothing */
+ end_ptr = dp + PNG_ROWBYTES(pixel_depth, row_width) - 1;
+ end_byte = *end_ptr;
+# ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
+ /* little-endian byte */
+ end_mask = (unsigned int)(0xff << end_mask);
+
+ else /* big-endian byte */
+# endif
+ end_mask = 0xff >> end_mask;
+ /* end_mask is now the bits to *keep* from the destination row */
+ }
+
+ /* For non-interlaced images this reduces to a memcpy(). A memcpy()
+ * will also happen if interlacing isn't supported or if the application
+ * does not call png_set_interlace_handling(). In the latter cases the
+ * caller just gets a sequence of the unexpanded rows from each interlace
+ * pass.
+ */
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ if (png_ptr->interlaced != 0 &&
+ (png_ptr->transformations & PNG_INTERLACE) != 0 &&
+ pass < 6 && (display == 0 ||
+ /* The following copies everything for 'display' on passes 0, 2 and 4. */
+ (display == 1 && (pass & 1) != 0)))
+ {
+ /* Narrow images may have no bits in a pass; the caller should handle
+ * this, but this test is cheap:
+ */
+ if (row_width <= PNG_PASS_START_COL(pass))
+ return;
+
+ if (pixel_depth < 8)
+ {
+ /* For pixel depths up to 4 bpp the 8-pixel mask can be expanded to fit
+ * into 32 bits, then a single loop over the bytes using the four byte
+ * values in the 32-bit mask can be used. For the 'display' option the
+ * expanded mask may also not require any masking within a byte. To
+ * make this work the PACKSWAP option must be taken into account - it
+ * simply requires the pixels to be reversed in each byte.
+ *
+ * The 'regular' case requires a mask for each of the first 6 passes,
+ * the 'display' case does a copy for the even passes in the range
+ * 0..6. This has already been handled in the test above.
+ *
+ * The masks are arranged as four bytes with the first byte to use in
+ * the lowest bits (little-endian) regardless of the order (PACKSWAP or
+ * not) of the pixels in each byte.
+ *
+ * NOTE: the whole of this logic depends on the caller of this function
+ * only calling it on rows appropriate to the pass. This function only
+ * understands the 'x' logic; the 'y' logic is handled by the caller.
+ *
+ * The following defines allow generation of compile time constant bit
+ * masks for each pixel depth and each possibility of swapped or not
+ * swapped bytes. Pass 'p' is in the range 0..6; 'x', a pixel index,
+ * is in the range 0..7; and the result is 1 if the pixel is to be
+ * copied in the pass, 0 if not. 'S' is for the sparkle method, 'B'
+ * for the block method.
+ *
+ * With some compilers a compile time expression of the general form:
+ *
+ * (shift >= 32) ? (a >> (shift-32)) : (b >> shift)
+ *
+ * Produces warnings with values of 'shift' in the range 33 to 63
+ * because the right hand side of the ?: expression is evaluated by
+ * the compiler even though it isn't used. Microsoft Visual C (various
+ * versions) and the Intel C compiler are known to do this. To avoid
+ * this the following macros are used in 1.5.6. This is a temporary
+ * solution to avoid destabilizing the code during the release process.
+ */
+# if PNG_USE_COMPILE_TIME_MASKS
+# define PNG_LSR(x,s) ((x)>>((s) & 0x1f))
+# define PNG_LSL(x,s) ((x)<<((s) & 0x1f))
+# else
+# define PNG_LSR(x,s) ((x)>>(s))
+# define PNG_LSL(x,s) ((x)<<(s))
+# endif
+# define S_COPY(p,x) (((p)<4 ? PNG_LSR(0x80088822,(3-(p))*8+(7-(x))) :\
+ PNG_LSR(0xaa55ff00,(7-(p))*8+(7-(x)))) & 1)
+# define B_COPY(p,x) (((p)<4 ? PNG_LSR(0xff0fff33,(3-(p))*8+(7-(x))) :\
+ PNG_LSR(0xff55ff00,(7-(p))*8+(7-(x)))) & 1)
+
+ /* Return a mask for pass 'p' pixel 'x' at depth 'd'. The mask is
+ * little endian - the first pixel is at bit 0 - however the extra
+ * parameter 's' can be set to cause the mask position to be swapped
+ * within each byte, to match the PNG format. This is done by XOR of
+ * the shift with 7, 6 or 4 for bit depths 1, 2 and 4.
+ */
+# define PIXEL_MASK(p,x,d,s) \
+ (PNG_LSL(((PNG_LSL(1U,(d)))-1),(((x)*(d))^((s)?8-(d):0))))
+
+ /* Hence generate the appropriate 'block' or 'sparkle' pixel copy mask.
+ */
+# define S_MASKx(p,x,d,s) (S_COPY(p,x)?PIXEL_MASK(p,x,d,s):0)
+# define B_MASKx(p,x,d,s) (B_COPY(p,x)?PIXEL_MASK(p,x,d,s):0)
+
+ /* Combine 8 of these to get the full mask. For the 1-bpp and 2-bpp
+ * cases the result needs replicating, for the 4-bpp case the above
+ * generates a full 32 bits.
+ */
+# define MASK_EXPAND(m,d) ((m)*((d)==1?0x01010101:((d)==2?0x00010001:1)))
+
+# define S_MASK(p,d,s) MASK_EXPAND(S_MASKx(p,0,d,s) + S_MASKx(p,1,d,s) +\
+ S_MASKx(p,2,d,s) + S_MASKx(p,3,d,s) + S_MASKx(p,4,d,s) +\
+ S_MASKx(p,5,d,s) + S_MASKx(p,6,d,s) + S_MASKx(p,7,d,s), d)
+
+# define B_MASK(p,d,s) MASK_EXPAND(B_MASKx(p,0,d,s) + B_MASKx(p,1,d,s) +\
+ B_MASKx(p,2,d,s) + B_MASKx(p,3,d,s) + B_MASKx(p,4,d,s) +\
+ B_MASKx(p,5,d,s) + B_MASKx(p,6,d,s) + B_MASKx(p,7,d,s), d)
+
+#if PNG_USE_COMPILE_TIME_MASKS
+ /* Utility macros to construct all the masks for a depth/swap
+ * combination. The 's' parameter says whether the format is PNG
+ * (big endian bytes) or not. Only the three odd-numbered passes are
+ * required for the display/block algorithm.
+ */
+# define S_MASKS(d,s) { S_MASK(0,d,s), S_MASK(1,d,s), S_MASK(2,d,s),\
+ S_MASK(3,d,s), S_MASK(4,d,s), S_MASK(5,d,s) }
+
+# define B_MASKS(d,s) { B_MASK(1,d,s), B_MASK(3,d,s), B_MASK(5,d,s) }
+
+# define DEPTH_INDEX(d) ((d)==1?0:((d)==2?1:2))
+
+ /* Hence the pre-compiled masks indexed by PACKSWAP (or not), depth and
+ * then pass:
+ */
+ static const png_uint_32 row_mask[2/*PACKSWAP*/][3/*depth*/][6] =
+ {
+ /* Little-endian byte masks for PACKSWAP */
+ { S_MASKS(1,0), S_MASKS(2,0), S_MASKS(4,0) },
+ /* Normal (big-endian byte) masks - PNG format */
+ { S_MASKS(1,1), S_MASKS(2,1), S_MASKS(4,1) }
+ };
+
+ /* display_mask has only three entries for the odd passes, so index by
+ * pass>>1.
+ */
+ static const png_uint_32 display_mask[2][3][3] =
+ {
+ /* Little-endian byte masks for PACKSWAP */
+ { B_MASKS(1,0), B_MASKS(2,0), B_MASKS(4,0) },
+ /* Normal (big-endian byte) masks - PNG format */
+ { B_MASKS(1,1), B_MASKS(2,1), B_MASKS(4,1) }
+ };
+
+# define MASK(pass,depth,display,png)\
+ ((display)?display_mask[png][DEPTH_INDEX(depth)][pass>>1]:\
+ row_mask[png][DEPTH_INDEX(depth)][pass])
+
+#else /* !PNG_USE_COMPILE_TIME_MASKS */
+ /* This is the runtime alternative: it seems unlikely that this will
+ * ever be either smaller or faster than the compile time approach.
+ */
+# define MASK(pass,depth,display,png)\
+ ((display)?B_MASK(pass,depth,png):S_MASK(pass,depth,png))
+#endif /* !USE_COMPILE_TIME_MASKS */
+
+ /* Use the appropriate mask to copy the required bits. In some cases
+ * the byte mask will be 0 or 0xff; optimize these cases. row_width is
+ * the number of pixels, but the code copies bytes, so it is necessary
+ * to special case the end.
+ */
+ png_uint_32 pixels_per_byte = 8 / pixel_depth;
+ png_uint_32 mask;
+
+# ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
+ mask = MASK(pass, pixel_depth, display, 0);
+
+ else
+# endif
+ mask = MASK(pass, pixel_depth, display, 1);
+
+ for (;;)
+ {
+ png_uint_32 m;
+
+ /* It doesn't matter in the following if png_uint_32 has more than
+ * 32 bits because the high bits always match those in m<<24; it is,
+ * however, essential to use OR here, not +, because of this.
+ */
+ m = mask;
+ mask = (m >> 8) | (m << 24); /* rotate right to good compilers */
+ m &= 0xff;
+
+ if (m != 0) /* something to copy */
+ {
+ if (m != 0xff)
+ *dp = (png_byte)((*dp & ~m) | (*sp & m));
+ else
+ *dp = *sp;
+ }
+
+ /* NOTE: this may overwrite the last byte with garbage if the image
+ * is not an exact number of bytes wide; libpng has always done
+ * this.
+ */
+ if (row_width <= pixels_per_byte)
+ break; /* May need to restore part of the last byte */
+
+ row_width -= pixels_per_byte;
+ ++dp;
+ ++sp;
+ }
+ }
+
+ else /* pixel_depth >= 8 */
+ {
+ unsigned int bytes_to_copy, bytes_to_jump;
+
+ /* Validate the depth - it must be a multiple of 8 */
+ if (pixel_depth & 7)
+ png_error(png_ptr, "invalid user transform pixel depth");
+
+ pixel_depth >>= 3; /* now in bytes */
+ row_width *= pixel_depth;
+
+ /* Regardless of pass number the Adam 7 interlace always results in a
+ * fixed number of pixels to copy then to skip. There may be a
+ * different number of pixels to skip at the start though.
+ */
+ {
+ unsigned int offset = PNG_PASS_START_COL(pass) * pixel_depth;
+
+ row_width -= offset;
+ dp += offset;
+ sp += offset;
+ }
+
+ /* Work out the bytes to copy. */
+ if (display != 0)
+ {
+ /* When doing the 'block' algorithm the pixel in the pass gets
+ * replicated to adjacent pixels. This is why the even (0,2,4,6)
+ * passes are skipped above - the entire expanded row is copied.
+ */
+ bytes_to_copy = (1<<((6-pass)>>1)) * pixel_depth;
+
+ /* But don't allow this number to exceed the actual row width. */
+ if (bytes_to_copy > row_width)
+ bytes_to_copy = (unsigned int)/*SAFE*/row_width;
+ }
+
+ else /* normal row; Adam7 only ever gives us one pixel to copy. */
+ bytes_to_copy = pixel_depth;
+
+ /* In Adam7 there is a constant offset between where the pixels go. */
+ bytes_to_jump = PNG_PASS_COL_OFFSET(pass) * pixel_depth;
+
+ /* And simply copy these bytes. Some optimization is possible here,
+ * depending on the value of 'bytes_to_copy'. Special case the low
+ * byte counts, which we know to be frequent.
+ *
+ * Notice that these cases all 'return' rather than 'break' - this
+ * avoids an unnecessary test on whether to restore the last byte
+ * below.
+ */
+ switch (bytes_to_copy)
+ {
+ case 1:
+ for (;;)
+ {
+ *dp = *sp;
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ dp += bytes_to_jump;
+ sp += bytes_to_jump;
+ row_width -= bytes_to_jump;
+ }
+
+ case 2:
+ /* There is a possibility of a partial copy at the end here; this
+ * slows the code down somewhat.
+ */
+ do
+ {
+ dp[0] = sp[0]; dp[1] = sp[1];
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ sp += bytes_to_jump;
+ dp += bytes_to_jump;
+ row_width -= bytes_to_jump;
+ }
+ while (row_width > 1);
+
+ /* And there can only be one byte left at this point: */
+ *dp = *sp;
+ return;
+
+ case 3:
+ /* This can only be the RGB case, so each copy is exactly one
+ * pixel and it is not necessary to check for a partial copy.
+ */
+ for (;;)
+ {
+ dp[0] = sp[0]; dp[1] = sp[1]; dp[2] = sp[2];
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ sp += bytes_to_jump;
+ dp += bytes_to_jump;
+ row_width -= bytes_to_jump;
+ }
+
+ default:
+#if PNG_ALIGN_TYPE != PNG_ALIGN_NONE
+ /* Check for double byte alignment and, if possible, use a
+ * 16-bit copy. Don't attempt this for narrow images - ones that
+ * are less than an interlace panel wide. Don't attempt it for
+ * wide bytes_to_copy either - use the memcpy there.
+ */
+ if (bytes_to_copy < 16 /*else use memcpy*/ &&
+ png_isaligned(dp, png_uint_16) &&
+ png_isaligned(sp, png_uint_16) &&
+ bytes_to_copy % (sizeof (png_uint_16)) == 0 &&
+ bytes_to_jump % (sizeof (png_uint_16)) == 0)
+ {
+ /* Everything is aligned for png_uint_16 copies, but try for
+ * png_uint_32 first.
+ */
+ if (png_isaligned(dp, png_uint_32) &&
+ png_isaligned(sp, png_uint_32) &&
+ bytes_to_copy % (sizeof (png_uint_32)) == 0 &&
+ bytes_to_jump % (sizeof (png_uint_32)) == 0)
+ {
+ png_uint_32p dp32 = png_aligncast(png_uint_32p,dp);
+ png_const_uint_32p sp32 = png_aligncastconst(
+ png_const_uint_32p, sp);
+ size_t skip = (bytes_to_jump-bytes_to_copy) /
+ (sizeof (png_uint_32));
+
+ do
+ {
+ size_t c = bytes_to_copy;
+ do
+ {
+ *dp32++ = *sp32++;
+ c -= (sizeof (png_uint_32));
+ }
+ while (c > 0);
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ dp32 += skip;
+ sp32 += skip;
+ row_width -= bytes_to_jump;
+ }
+ while (bytes_to_copy <= row_width);
+
+ /* Get to here when the row_width truncates the final copy.
+ * There will be 1-3 bytes left to copy, so don't try the
+ * 16-bit loop below.
+ */
+ dp = (png_bytep)dp32;
+ sp = (png_const_bytep)sp32;
+ do
+ *dp++ = *sp++;
+ while (--row_width > 0);
+ return;
+ }
+
+ /* Else do it in 16-bit quantities, but only if the size is
+ * not too large.
+ */
+ else
+ {
+ png_uint_16p dp16 = png_aligncast(png_uint_16p, dp);
+ png_const_uint_16p sp16 = png_aligncastconst(
+ png_const_uint_16p, sp);
+ size_t skip = (bytes_to_jump-bytes_to_copy) /
+ (sizeof (png_uint_16));
+
+ do
+ {
+ size_t c = bytes_to_copy;
+ do
+ {
+ *dp16++ = *sp16++;
+ c -= (sizeof (png_uint_16));
+ }
+ while (c > 0);
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ dp16 += skip;
+ sp16 += skip;
+ row_width -= bytes_to_jump;
+ }
+ while (bytes_to_copy <= row_width);
+
+ /* End of row - 1 byte left, bytes_to_copy > row_width: */
+ dp = (png_bytep)dp16;
+ sp = (png_const_bytep)sp16;
+ do
+ *dp++ = *sp++;
+ while (--row_width > 0);
+ return;
+ }
+ }
+#endif /* ALIGN_TYPE code */
+
+ /* The true default - use a memcpy: */
+ for (;;)
+ {
+ memcpy(dp, sp, bytes_to_copy);
+
+ if (row_width <= bytes_to_jump)
+ return;
+
+ sp += bytes_to_jump;
+ dp += bytes_to_jump;
+ row_width -= bytes_to_jump;
+ if (bytes_to_copy > row_width)
+ bytes_to_copy = (unsigned int)/*SAFE*/row_width;
+ }
+ }
+
+ /* NOT REACHED*/
+ } /* pixel_depth >= 8 */
+
+ /* Here if pixel_depth < 8 to check 'end_ptr' below. */
+ }
+ else
+#endif /* READ_INTERLACING */
+
+ /* If here then the switch above wasn't used so just memcpy the whole row
+ * from the temporary row buffer (notice that this overwrites the end of the
+ * destination row if it is a partial byte.)
+ */
+ memcpy(dp, sp, PNG_ROWBYTES(pixel_depth, row_width));
+
+ /* Restore the overwritten bits from the last byte if necessary. */
+ if (end_ptr != NULL)
+ *end_ptr = (png_byte)((end_byte & end_mask) | (*end_ptr & ~end_mask));
+}
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+void /* PRIVATE */
+png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
+ png_uint_32 transformations /* Because these may affect the byte layout */)
+{
+ png_debug(1, "in png_do_read_interlace");
+ if (row != NULL && row_info != NULL)
+ {
+ png_uint_32 final_width;
+
+ final_width = row_info->width * png_pass_inc[pass];
+
+ switch (row_info->pixel_depth)
+ {
+ case 1:
+ {
+ png_bytep sp = row + (size_t)((row_info->width - 1) >> 3);
+ png_bytep dp = row + (size_t)((final_width - 1) >> 3);
+ unsigned int sshift, dshift;
+ unsigned int s_start, s_end;
+ int s_inc;
+ int jstop = (int)png_pass_inc[pass];
+ png_byte v;
+ png_uint_32 i;
+ int j;
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if ((transformations & PNG_PACKSWAP) != 0)
+ {
+ sshift = ((row_info->width + 7) & 0x07);
+ dshift = ((final_width + 7) & 0x07);
+ s_start = 7;
+ s_end = 0;
+ s_inc = -1;
+ }
+
+ else
+#endif
+ {
+ sshift = 7 - ((row_info->width + 7) & 0x07);
+ dshift = 7 - ((final_width + 7) & 0x07);
+ s_start = 0;
+ s_end = 7;
+ s_inc = 1;
+ }
+
+ for (i = 0; i < row_info->width; i++)
+ {
+ v = (png_byte)((*sp >> sshift) & 0x01);
+ for (j = 0; j < jstop; j++)
+ {
+ unsigned int tmp = *dp & (0x7f7f >> (7 - dshift));
+ tmp |= (unsigned int)(v << dshift);
+ *dp = (png_byte)(tmp & 0xff);
+
+ if (dshift == s_end)
+ {
+ dshift = s_start;
+ dp--;
+ }
+
+ else
+ dshift = (unsigned int)((int)dshift + s_inc);
+ }
+
+ if (sshift == s_end)
+ {
+ sshift = s_start;
+ sp--;
+ }
+
+ else
+ sshift = (unsigned int)((int)sshift + s_inc);
+ }
+ break;
+ }
+
+ case 2:
+ {
+ png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2);
+ png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2);
+ unsigned int sshift, dshift;
+ unsigned int s_start, s_end;
+ int s_inc;
+ int jstop = (int)png_pass_inc[pass];
+ png_uint_32 i;
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if ((transformations & PNG_PACKSWAP) != 0)
+ {
+ sshift = (((row_info->width + 3) & 0x03) << 1);
+ dshift = (((final_width + 3) & 0x03) << 1);
+ s_start = 6;
+ s_end = 0;
+ s_inc = -2;
+ }
+
+ else
+#endif
+ {
+ sshift = ((3 - ((row_info->width + 3) & 0x03)) << 1);
+ dshift = ((3 - ((final_width + 3) & 0x03)) << 1);
+ s_start = 0;
+ s_end = 6;
+ s_inc = 2;
+ }
+
+ for (i = 0; i < row_info->width; i++)
+ {
+ png_byte v;
+ int j;
+
+ v = (png_byte)((*sp >> sshift) & 0x03);
+ for (j = 0; j < jstop; j++)
+ {
+ unsigned int tmp = *dp & (0x3f3f >> (6 - dshift));
+ tmp |= (unsigned int)(v << dshift);
+ *dp = (png_byte)(tmp & 0xff);
+
+ if (dshift == s_end)
+ {
+ dshift = s_start;
+ dp--;
+ }
+
+ else
+ dshift = (unsigned int)((int)dshift + s_inc);
+ }
+
+ if (sshift == s_end)
+ {
+ sshift = s_start;
+ sp--;
+ }
+
+ else
+ sshift = (unsigned int)((int)sshift + s_inc);
+ }
+ break;
+ }
+
+ case 4:
+ {
+ png_bytep sp = row + (size_t)((row_info->width - 1) >> 1);
+ png_bytep dp = row + (size_t)((final_width - 1) >> 1);
+ unsigned int sshift, dshift;
+ unsigned int s_start, s_end;
+ int s_inc;
+ png_uint_32 i;
+ int jstop = (int)png_pass_inc[pass];
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if ((transformations & PNG_PACKSWAP) != 0)
+ {
+ sshift = (((row_info->width + 1) & 0x01) << 2);
+ dshift = (((final_width + 1) & 0x01) << 2);
+ s_start = 4;
+ s_end = 0;
+ s_inc = -4;
+ }
+
+ else
+#endif
+ {
+ sshift = ((1 - ((row_info->width + 1) & 0x01)) << 2);
+ dshift = ((1 - ((final_width + 1) & 0x01)) << 2);
+ s_start = 0;
+ s_end = 4;
+ s_inc = 4;
+ }
+
+ for (i = 0; i < row_info->width; i++)
+ {
+ png_byte v = (png_byte)((*sp >> sshift) & 0x0f);
+ int j;
+
+ for (j = 0; j < jstop; j++)
+ {
+ unsigned int tmp = *dp & (0xf0f >> (4 - dshift));
+ tmp |= (unsigned int)(v << dshift);
+ *dp = (png_byte)(tmp & 0xff);
+
+ if (dshift == s_end)
+ {
+ dshift = s_start;
+ dp--;
+ }
+
+ else
+ dshift = (unsigned int)((int)dshift + s_inc);
+ }
+
+ if (sshift == s_end)
+ {
+ sshift = s_start;
+ sp--;
+ }
+
+ else
+ sshift = (unsigned int)((int)sshift + s_inc);
+ }
+ break;
+ }
+
+ default:
+ {
+ size_t pixel_bytes = (row_info->pixel_depth >> 3);
+
+ png_bytep sp = row + (size_t)(row_info->width - 1)
+ * pixel_bytes;
+
+ png_bytep dp = row + (size_t)(final_width - 1) * pixel_bytes;
+
+ int jstop = (int)png_pass_inc[pass];
+ png_uint_32 i;
+
+ for (i = 0; i < row_info->width; i++)
+ {
+ png_byte v[8]; /* SAFE; pixel_depth does not exceed 64 */
+ int j;
+
+ memcpy(v, sp, pixel_bytes);
+
+ for (j = 0; j < jstop; j++)
+ {
+ memcpy(dp, v, pixel_bytes);
+ dp -= pixel_bytes;
+ }
+
+ sp -= pixel_bytes;
+ }
+ break;
+ }
+ }
+
+ row_info->width = final_width;
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width);
+ }
+#ifndef PNG_READ_PACKSWAP_SUPPORTED
+ PNG_UNUSED(transformations) /* Silence compiler warning */
+#endif
+}
+#endif /* READ_INTERLACING */
+
+static void
+png_read_filter_row_sub(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ size_t i;
+ size_t istop = row_info->rowbytes;
+ unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
+ png_bytep rp = row + bpp;
+
+ PNG_UNUSED(prev_row)
+
+ for (i = bpp; i < istop; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
+ rp++;
+ }
+}
+
+static void
+png_read_filter_row_up(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ size_t i;
+ size_t istop = row_info->rowbytes;
+ png_bytep rp = row;
+ png_const_bytep pp = prev_row;
+
+ for (i = 0; i < istop; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
+ rp++;
+ }
+}
+
+static void
+png_read_filter_row_avg(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ size_t i;
+ png_bytep rp = row;
+ png_const_bytep pp = prev_row;
+ unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
+ size_t istop = row_info->rowbytes - bpp;
+
+ for (i = 0; i < bpp; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) +
+ ((int)(*pp++) / 2 )) & 0xff);
+
+ rp++;
+ }
+
+ for (i = 0; i < istop; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) +
+ (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
+
+ rp++;
+ }
+}
+
+static void
+png_read_filter_row_paeth_1byte_pixel(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ png_bytep rp_end = row + row_info->rowbytes;
+ int a, c;
+
+ /* First pixel/byte */
+ c = *prev_row++;
+ a = *row + c;
+ *row++ = (png_byte)a;
+
+ /* Remainder */
+ while (row < rp_end)
+ {
+ int b, pa, pb, pc, p;
+
+ a &= 0xff; /* From previous iteration or start */
+ b = *prev_row++;
+
+ p = b - c;
+ pc = a - c;
+
+#ifdef PNG_USE_ABS
+ pa = abs(p);
+ pb = abs(pc);
+ pc = abs(p + pc);
+#else
+ pa = p < 0 ? -p : p;
+ pb = pc < 0 ? -pc : pc;
+ pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#endif
+
+ /* Find the best predictor, the least of pa, pb, pc favoring the earlier
+ * ones in the case of a tie.
+ */
+ if (pb < pa)
+ {
+ pa = pb; a = b;
+ }
+ if (pc < pa) a = c;
+
+ /* Calculate the current pixel in a, and move the previous row pixel to c
+ * for the next time round the loop
+ */
+ c = b;
+ a += *row;
+ *row++ = (png_byte)a;
+ }
+}
+
+static void
+png_read_filter_row_paeth_multibyte_pixel(png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row)
+{
+ unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
+ png_bytep rp_end = row + bpp;
+
+ /* Process the first pixel in the row completely (this is the same as 'up'
+ * because there is only one candidate predictor for the first row).
+ */
+ while (row < rp_end)
+ {
+ int a = *row + *prev_row++;
+ *row++ = (png_byte)a;
+ }
+
+ /* Remainder */
+ rp_end = rp_end + (row_info->rowbytes - bpp);
+
+ while (row < rp_end)
+ {
+ int a, b, c, pa, pb, pc, p;
+
+ c = *(prev_row - bpp);
+ a = *(row - bpp);
+ b = *prev_row++;
+
+ p = b - c;
+ pc = a - c;
+
+#ifdef PNG_USE_ABS
+ pa = abs(p);
+ pb = abs(pc);
+ pc = abs(p + pc);
+#else
+ pa = p < 0 ? -p : p;
+ pb = pc < 0 ? -pc : pc;
+ pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#endif
+
+ if (pb < pa)
+ {
+ pa = pb; a = b;
+ }
+ if (pc < pa) a = c;
+
+ a += *row;
+ *row++ = (png_byte)a;
+ }
+}
+
+static void
+png_init_filter_functions(png_structrp pp)
+ /* This function is called once for every PNG image (except for PNG images
+ * that only use PNG_FILTER_VALUE_NONE for all rows) to set the
+ * implementations required to reverse the filtering of PNG rows. Reversing
+ * the filter is the first transformation performed on the row data. It is
+ * performed in place, therefore an implementation can be selected based on
+ * the image pixel format. If the implementation depends on image width then
+ * take care to ensure that it works correctly if the image is interlaced -
+ * interlacing causes the actual row width to vary.
+ */
+{
+ unsigned int bpp = (pp->pixel_depth + 7) >> 3;
+
+ pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub;
+ pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up;
+ pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg;
+ if (bpp == 1)
+ pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+ png_read_filter_row_paeth_1byte_pixel;
+ else
+ pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+ png_read_filter_row_paeth_multibyte_pixel;
+
+#ifdef PNG_FILTER_OPTIMIZATIONS
+ /* To use this define PNG_FILTER_OPTIMIZATIONS as the name of a function to
+ * call to install hardware optimizations for the above functions; simply
+ * replace whatever elements of the pp->read_filter[] array with a hardware
+ * specific (or, for that matter, generic) optimization.
+ *
+ * To see an example of this examine what configure.ac does when
+ * --enable-arm-neon is specified on the command line.
+ */
+ PNG_FILTER_OPTIMIZATIONS(pp, bpp);
+#endif
+}
+
+void /* PRIVATE */
+png_read_filter_row(png_structrp pp, png_row_infop row_info, png_bytep row,
+ png_const_bytep prev_row, int filter)
+{
+ /* OPTIMIZATION: DO NOT MODIFY THIS FUNCTION, instead #define
+ * PNG_FILTER_OPTIMIZATIONS to a function that overrides the generic
+ * implementations. See png_init_filter_functions above.
+ */
+ if (filter > PNG_FILTER_VALUE_NONE && filter < PNG_FILTER_VALUE_LAST)
+ {
+ if (pp->read_filter[0] == NULL)
+ png_init_filter_functions(pp);
+
+ pp->read_filter[filter-1](row_info, row, prev_row);
+ }
+}
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+void /* PRIVATE */
+png_read_IDAT_data(png_structrp png_ptr, png_bytep output,
+ png_alloc_size_t avail_out)
+{
+ /* Loop reading IDATs and decompressing the result into output[avail_out] */
+ png_ptr->zstream.next_out = output;
+ png_ptr->zstream.avail_out = 0; /* safety: set below */
+
+ if (output == NULL)
+ avail_out = 0;
+
+ do
+ {
+ int ret;
+ png_byte tmpbuf[PNG_INFLATE_BUF_SIZE];
+
+ if (png_ptr->zstream.avail_in == 0)
+ {
+ uInt avail_in;
+ png_bytep buffer;
+
+ while (png_ptr->idat_size == 0)
+ {
+ png_crc_finish(png_ptr, 0);
+
+ png_ptr->idat_size = png_read_chunk_header(png_ptr);
+ /* This is an error even in the 'check' case because the code just
+ * consumed a non-IDAT header.
+ */
+ if (png_ptr->chunk_name != png_IDAT)
+ png_error(png_ptr, "Not enough image data");
+ }
+
+ avail_in = png_ptr->IDAT_read_size;
+
+ if (avail_in > png_chunk_max(png_ptr))
+ avail_in = (uInt)/*SAFE*/png_chunk_max(png_ptr);
+
+ if (avail_in > png_ptr->idat_size)
+ avail_in = (uInt)png_ptr->idat_size;
+
+ /* A PNG with a gradually increasing IDAT size will defeat this attempt
+ * to minimize memory usage by causing lots of re-allocs, but
+ * realistically doing IDAT_read_size re-allocs is not likely to be a
+ * big problem.
+ *
+ * An error here corresponds to the system being out of memory.
+ */
+ buffer = png_read_buffer(png_ptr, avail_in);
+
+ if (buffer == NULL)
+ png_chunk_error(png_ptr, "out of memory");
+
+ png_crc_read(png_ptr, buffer, avail_in);
+ png_ptr->idat_size -= avail_in;
+
+ png_ptr->zstream.next_in = buffer;
+ png_ptr->zstream.avail_in = avail_in;
+ }
+
+ /* And set up the output side. */
+ if (output != NULL) /* standard read */
+ {
+ uInt out = ZLIB_IO_MAX;
+
+ if (out > avail_out)
+ out = (uInt)avail_out;
+
+ avail_out -= out;
+ png_ptr->zstream.avail_out = out;
+ }
+
+ else /* after last row, checking for end */
+ {
+ png_ptr->zstream.next_out = tmpbuf;
+ png_ptr->zstream.avail_out = (sizeof tmpbuf);
+ }
+
+ /* Use NO_FLUSH; this gives zlib the maximum opportunity to optimize the
+ * process. If the LZ stream is truncated the sequential reader will
+ * terminally damage the stream, above, by reading the chunk header of the
+ * following chunk (it then exits with png_error).
+ *
+ * TODO: deal more elegantly with truncated IDAT lists.
+ */
+ ret = PNG_INFLATE(png_ptr, Z_NO_FLUSH);
+
+ /* Take the unconsumed output back. */
+ if (output != NULL)
+ avail_out += png_ptr->zstream.avail_out;
+
+ else /* avail_out counts the extra bytes */
+ avail_out += (sizeof tmpbuf) - png_ptr->zstream.avail_out;
+
+ png_ptr->zstream.avail_out = 0;
+
+ if (ret == Z_STREAM_END)
+ {
+ /* Do this for safety; we won't read any more into this row. */
+ png_ptr->zstream.next_out = NULL;
+
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
+
+ if (png_ptr->zstream.avail_in > 0 || png_ptr->idat_size > 0)
+ png_chunk_benign_error(png_ptr, "Extra compressed data");
+ break;
+ }
+
+ if (ret != Z_OK)
+ {
+ png_zstream_error(png_ptr, ret);
+
+ if (output != NULL)
+ png_chunk_error(png_ptr, png_ptr->zstream.msg);
+
+ else /* checking */
+ {
+ png_chunk_benign_error(png_ptr, png_ptr->zstream.msg);
+ return;
+ }
+ }
+ } while (avail_out > 0);
+
+ if (avail_out > 0)
+ {
+ /* The stream ended before the image; this is the same as too few IDATs so
+ * should be handled the same way.
+ */
+ if (output != NULL)
+ png_error(png_ptr, "Not enough image data");
+
+ else /* the deflate stream contained extra data */
+ png_chunk_benign_error(png_ptr, "Too much image data");
+ }
+}
+
+void /* PRIVATE */
+png_read_finish_IDAT(png_structrp png_ptr)
+{
+ /* We don't need any more data and the stream should have ended, however the
+ * LZ end code may actually not have been processed. In this case we must
+ * read it otherwise stray unread IDAT data or, more likely, an IDAT chunk
+ * may still remain to be consumed.
+ */
+ if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
+ {
+ /* The NULL causes png_read_IDAT_data to swallow any remaining bytes in
+ * the compressed stream, but the stream may be damaged too, so even after
+ * this call we may need to terminate the zstream ownership.
+ */
+ png_read_IDAT_data(png_ptr, NULL, 0);
+ png_ptr->zstream.next_out = NULL; /* safety */
+
+ /* Now clear everything out for safety; the following may not have been
+ * done.
+ */
+ if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
+ {
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
+ }
+ }
+
+ /* If the zstream has not been released do it now *and* terminate the reading
+ * of the final IDAT chunk.
+ */
+ if (png_ptr->zowner == png_IDAT)
+ {
+ /* Always do this; the pointers otherwise point into the read buffer. */
+ png_ptr->zstream.next_in = NULL;
+ png_ptr->zstream.avail_in = 0;
+
+ /* Now we no longer own the zstream. */
+ png_ptr->zowner = 0;
+
+ /* The slightly weird semantics of the sequential IDAT reading is that we
+ * are always in or at the end of an IDAT chunk, so we always need to do a
+ * crc_finish here. If idat_size is non-zero we also need to read the
+ * spurious bytes at the end of the chunk now.
+ */
+ (void)png_crc_finish(png_ptr, png_ptr->idat_size);
+ }
+}
+
+void /* PRIVATE */
+png_read_finish_row(png_structrp png_ptr)
+{
+ png_debug(1, "in png_read_finish_row");
+ png_ptr->row_number++;
+ if (png_ptr->row_number < png_ptr->num_rows)
+ return;
+
+ if (png_ptr->interlaced != 0)
+ {
+ png_ptr->row_number = 0;
+
+ /* TO DO: don't do this if prev_row isn't needed (requires
+ * read-ahead of the next row's filter byte.
+ */
+ memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+
+ do
+ {
+ png_ptr->pass++;
+
+ if (png_ptr->pass >= 7)
+ break;
+
+ png_ptr->iwidth = (png_ptr->width +
+ png_pass_inc[png_ptr->pass] - 1 -
+ png_pass_start[png_ptr->pass]) /
+ png_pass_inc[png_ptr->pass];
+
+ if ((png_ptr->transformations & PNG_INTERLACE) == 0)
+ {
+ png_ptr->num_rows = (png_ptr->height +
+ png_pass_yinc[png_ptr->pass] - 1 -
+ png_pass_ystart[png_ptr->pass]) /
+ png_pass_yinc[png_ptr->pass];
+ }
+
+ else /* if (png_ptr->transformations & PNG_INTERLACE) */
+ break; /* libpng deinterlacing sees every row */
+
+ } while (png_ptr->num_rows == 0 || png_ptr->iwidth == 0);
+
+ if (png_ptr->pass < 7)
+ return;
+ }
+
+ /* Here after at the end of the last row of the last pass. */
+ png_read_finish_IDAT(png_ptr);
+}
+#endif /* SEQUENTIAL_READ */
+
+void /* PRIVATE */
+png_read_start_row(png_structrp png_ptr)
+{
+ unsigned int max_pixel_depth;
+ size_t row_bytes;
+
+ png_debug(1, "in png_read_start_row");
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+ png_init_read_transformations(png_ptr);
+#endif
+ if (png_ptr->interlaced != 0)
+ {
+ if ((png_ptr->transformations & PNG_INTERLACE) == 0)
+ png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
+ png_pass_ystart[0]) / png_pass_yinc[0];
+
+ else
+ png_ptr->num_rows = png_ptr->height;
+
+ png_ptr->iwidth = (png_ptr->width +
+ png_pass_inc[png_ptr->pass] - 1 -
+ png_pass_start[png_ptr->pass]) /
+ png_pass_inc[png_ptr->pass];
+ }
+
+ else
+ {
+ png_ptr->num_rows = png_ptr->height;
+ png_ptr->iwidth = png_ptr->width;
+ }
+
+ max_pixel_depth = (unsigned int)png_ptr->pixel_depth;
+
+ /* WARNING: * png_read_transform_info (pngrtran.c) performs a simpler set of
+ * calculations to calculate the final pixel depth, then
+ * png_do_read_transforms actually does the transforms. This means that the
+ * code which effectively calculates this value is actually repeated in three
+ * separate places. They must all match. Innocent changes to the order of
+ * transformations can and will break libpng in a way that causes memory
+ * overwrites.
+ *
+ * TODO: fix this.
+ */
+#ifdef PNG_READ_PACK_SUPPORTED
+ if ((png_ptr->transformations & PNG_PACK) != 0 && png_ptr->bit_depth < 8)
+ max_pixel_depth = 8;
+#endif
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ if ((png_ptr->transformations & PNG_EXPAND) != 0)
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (png_ptr->num_trans != 0)
+ max_pixel_depth = 32;
+
+ else
+ max_pixel_depth = 24;
+ }
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ if (max_pixel_depth < 8)
+ max_pixel_depth = 8;
+
+ if (png_ptr->num_trans != 0)
+ max_pixel_depth *= 2;
+ }
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ if (png_ptr->num_trans != 0)
+ {
+ max_pixel_depth *= 4;
+ max_pixel_depth /= 3;
+ }
+ }
+ }
+#endif
+
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+ if ((png_ptr->transformations & PNG_EXPAND_16) != 0)
+ {
+# ifdef PNG_READ_EXPAND_SUPPORTED
+ /* In fact it is an error if it isn't supported, but checking is
+ * the safe way.
+ */
+ if ((png_ptr->transformations & PNG_EXPAND) != 0)
+ {
+ if (png_ptr->bit_depth < 16)
+ max_pixel_depth *= 2;
+ }
+ else
+# endif
+ png_ptr->transformations &= ~PNG_EXPAND_16;
+ }
+#endif
+
+#ifdef PNG_READ_FILLER_SUPPORTED
+ if ((png_ptr->transformations & (PNG_FILLER)) != 0)
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ if (max_pixel_depth <= 8)
+ max_pixel_depth = 16;
+
+ else
+ max_pixel_depth = 32;
+ }
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB ||
+ png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (max_pixel_depth <= 32)
+ max_pixel_depth = 32;
+
+ else
+ max_pixel_depth = 64;
+ }
+ }
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0)
+ {
+ if (
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ (png_ptr->num_trans != 0 &&
+ (png_ptr->transformations & PNG_EXPAND) != 0) ||
+#endif
+#ifdef PNG_READ_FILLER_SUPPORTED
+ (png_ptr->transformations & (PNG_FILLER)) != 0 ||
+#endif
+ png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ if (max_pixel_depth <= 16)
+ max_pixel_depth = 32;
+
+ else
+ max_pixel_depth = 64;
+ }
+
+ else
+ {
+ if (max_pixel_depth <= 8)
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ max_pixel_depth = 32;
+
+ else
+ max_pixel_depth = 24;
+ }
+
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ max_pixel_depth = 64;
+
+ else
+ max_pixel_depth = 48;
+ }
+ }
+#endif
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \
+defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
+ if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
+ {
+ unsigned int user_pixel_depth = png_ptr->user_transform_depth *
+ png_ptr->user_transform_channels;
+
+ if (user_pixel_depth > max_pixel_depth)
+ max_pixel_depth = user_pixel_depth;
+ }
+#endif
+
+ /* This value is stored in png_struct and double checked in the row read
+ * code.
+ */
+ png_ptr->maximum_pixel_depth = (png_byte)max_pixel_depth;
+ png_ptr->transformed_pixel_depth = 0; /* calculated on demand */
+
+ /* Align the width on the next larger 8 pixels. Mainly used
+ * for interlacing
+ */
+ row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7));
+ /* Calculate the maximum bytes needed, adding a byte and a pixel
+ * for safety's sake
+ */
+ row_bytes = PNG_ROWBYTES(max_pixel_depth, row_bytes) +
+ 1 + ((max_pixel_depth + 7) >> 3U);
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (row_bytes > (png_uint_32)65536L)
+ png_error(png_ptr, "This image requires a row greater than 64KB");
+#endif
+
+ if (row_bytes + 48 > png_ptr->old_big_row_buf_size)
+ {
+ png_free(png_ptr, png_ptr->big_row_buf);
+ png_free(png_ptr, png_ptr->big_prev_row);
+
+ if (png_ptr->interlaced != 0)
+ png_ptr->big_row_buf = (png_bytep)png_calloc(png_ptr,
+ row_bytes + 48);
+
+ else
+ png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes + 48);
+
+ png_ptr->big_prev_row = (png_bytep)png_malloc(png_ptr, row_bytes + 48);
+
+#ifdef PNG_ALIGNED_MEMORY_SUPPORTED
+ /* Use 16-byte aligned memory for row_buf with at least 16 bytes
+ * of padding before and after row_buf; treat prev_row similarly.
+ * NOTE: the alignment is to the start of the pixels, one beyond the start
+ * of the buffer, because of the filter byte. Prior to libpng 1.5.6 this
+ * was incorrect; the filter byte was aligned, which had the exact
+ * opposite effect of that intended.
+ */
+ {
+ png_bytep temp = png_ptr->big_row_buf + 32;
+ size_t extra = (size_t)temp & 0x0f;
+ png_ptr->row_buf = temp - extra - 1/*filter byte*/;
+
+ temp = png_ptr->big_prev_row + 32;
+ extra = (size_t)temp & 0x0f;
+ png_ptr->prev_row = temp - extra - 1/*filter byte*/;
+ }
+#else
+ /* Use 31 bytes of padding before and 17 bytes after row_buf. */
+ png_ptr->row_buf = png_ptr->big_row_buf + 31;
+ png_ptr->prev_row = png_ptr->big_prev_row + 31;
+#endif
+ png_ptr->old_big_row_buf_size = row_bytes + 48;
+ }
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (png_ptr->rowbytes > 65535)
+ png_error(png_ptr, "This image requires a row greater than 64KB");
+
+#endif
+ if (png_ptr->rowbytes > (PNG_SIZE_MAX - 1))
+ png_error(png_ptr, "Row has too many bytes to allocate in memory");
+
+ memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+
+ png_debug1(3, "width = %u,", png_ptr->width);
+ png_debug1(3, "height = %u,", png_ptr->height);
+ png_debug1(3, "iwidth = %u,", png_ptr->iwidth);
+ png_debug1(3, "num_rows = %u,", png_ptr->num_rows);
+ png_debug1(3, "rowbytes = %lu,", (unsigned long)png_ptr->rowbytes);
+ png_debug1(3, "irowbytes = %lu",
+ (unsigned long)PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1);
+
+ /* The sequential reader needs a buffer for IDAT, but the progressive reader
+ * does not, so free the read buffer now regardless; the sequential reader
+ * reallocates it on demand.
+ */
+ if (png_ptr->read_buffer != NULL)
+ {
+ png_bytep buffer = png_ptr->read_buffer;
+
+ png_ptr->read_buffer_size = 0;
+ png_ptr->read_buffer = NULL;
+ png_free(png_ptr, buffer);
+ }
+
+ /* Finally claim the zstream for the inflate of the IDAT data, use the bits
+ * value from the stream (note that this will result in a fatal error if the
+ * IDAT stream has a bogus deflate header window_bits value, but this should
+ * not be happening any longer!)
+ */
+ if (png_inflate_claim(png_ptr, png_IDAT) != Z_OK)
+ png_error(png_ptr, png_ptr->zstream.msg);
+
+ png_ptr->flags |= PNG_FLAG_ROW_INIT;
+}
+#endif /* READ */
diff --git a/libs/imagequant/external/libpng/pngset.c b/libs/imagequant/external/libpng/pngset.c
new file mode 100644
index 00000000..3e63c272
--- /dev/null
+++ b/libs/imagequant/external/libpng/pngset.c
@@ -0,0 +1,1986 @@
+/* pngset.c - storage of image information into info struct
+ *
+ * Copyright (c) 2018-2025 Cosmin Truta
+ * Copyright (c) 1998-2018 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * The functions here are used during reads to store data from the file
+ * into the info struct, and during writes to store application data
+ * into the info struct for writing into the file. This abstracts the
+ * info struct and allows us to change the structure in the future.
+ */
+
+#include "pngpriv.h"
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+
+#ifdef PNG_bKGD_SUPPORTED
+void PNGAPI
+png_set_bKGD(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_const_color_16p background)
+{
+ png_debug1(1, "in %s storage function", "bKGD");
+
+ if (png_ptr == NULL || info_ptr == NULL || background == NULL)
+ return;
+
+ info_ptr->background = *background;
+ info_ptr->valid |= PNG_INFO_bKGD;
+}
+#endif
+
+#ifdef PNG_cHRM_SUPPORTED
+void PNGFAPI
+png_set_cHRM_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x,
+ png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y,
+ png_fixed_point blue_x, png_fixed_point blue_y)
+{
+ png_debug1(1, "in %s storage function", "cHRM fixed");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ info_ptr->cHRM.redx = red_x;
+ info_ptr->cHRM.redy = red_y;
+ info_ptr->cHRM.greenx = green_x;
+ info_ptr->cHRM.greeny = green_y;
+ info_ptr->cHRM.bluex = blue_x;
+ info_ptr->cHRM.bluey = blue_y;
+ info_ptr->cHRM.whitex = white_x;
+ info_ptr->cHRM.whitey = white_y;
+
+ info_ptr->valid |= PNG_INFO_cHRM;
+}
+
+void PNGFAPI
+png_set_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_fixed_point int_red_X, png_fixed_point int_red_Y,
+ png_fixed_point int_red_Z, png_fixed_point int_green_X,
+ png_fixed_point int_green_Y, png_fixed_point int_green_Z,
+ png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
+ png_fixed_point int_blue_Z)
+{
+ png_XYZ XYZ;
+ png_xy xy;
+
+ png_debug1(1, "in %s storage function", "cHRM XYZ fixed");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ XYZ.red_X = int_red_X;
+ XYZ.red_Y = int_red_Y;
+ XYZ.red_Z = int_red_Z;
+ XYZ.green_X = int_green_X;
+ XYZ.green_Y = int_green_Y;
+ XYZ.green_Z = int_green_Z;
+ XYZ.blue_X = int_blue_X;
+ XYZ.blue_Y = int_blue_Y;
+ XYZ.blue_Z = int_blue_Z;
+
+ if (png_xy_from_XYZ(&xy, &XYZ) == 0)
+ {
+ info_ptr->cHRM = xy;
+ info_ptr->valid |= PNG_INFO_cHRM;
+ }
+
+ else
+ png_app_error(png_ptr, "invalid cHRM XYZ");
+}
+
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_cHRM(png_const_structrp png_ptr, png_inforp info_ptr,
+ double white_x, double white_y, double red_x, double red_y,
+ double green_x, double green_y, double blue_x, double blue_y)
+{
+ png_set_cHRM_fixed(png_ptr, info_ptr,
+ png_fixed(png_ptr, white_x, "cHRM White X"),
+ png_fixed(png_ptr, white_y, "cHRM White Y"),
+ png_fixed(png_ptr, red_x, "cHRM Red X"),
+ png_fixed(png_ptr, red_y, "cHRM Red Y"),
+ png_fixed(png_ptr, green_x, "cHRM Green X"),
+ png_fixed(png_ptr, green_y, "cHRM Green Y"),
+ png_fixed(png_ptr, blue_x, "cHRM Blue X"),
+ png_fixed(png_ptr, blue_y, "cHRM Blue Y"));
+}
+
+void PNGAPI
+png_set_cHRM_XYZ(png_const_structrp png_ptr, png_inforp info_ptr, double red_X,
+ double red_Y, double red_Z, double green_X, double green_Y, double green_Z,
+ double blue_X, double blue_Y, double blue_Z)
+{
+ png_set_cHRM_XYZ_fixed(png_ptr, info_ptr,
+ png_fixed(png_ptr, red_X, "cHRM Red X"),
+ png_fixed(png_ptr, red_Y, "cHRM Red Y"),
+ png_fixed(png_ptr, red_Z, "cHRM Red Z"),
+ png_fixed(png_ptr, green_X, "cHRM Green X"),
+ png_fixed(png_ptr, green_Y, "cHRM Green Y"),
+ png_fixed(png_ptr, green_Z, "cHRM Green Z"),
+ png_fixed(png_ptr, blue_X, "cHRM Blue X"),
+ png_fixed(png_ptr, blue_Y, "cHRM Blue Y"),
+ png_fixed(png_ptr, blue_Z, "cHRM Blue Z"));
+}
+# endif /* FLOATING_POINT */
+
+#endif /* cHRM */
+
+#ifdef PNG_cICP_SUPPORTED
+void PNGAPI
+png_set_cICP(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_byte colour_primaries, png_byte transfer_function,
+ png_byte matrix_coefficients, png_byte video_full_range_flag)
+{
+ png_debug1(1, "in %s storage function", "cICP");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ info_ptr->cicp_colour_primaries = colour_primaries;
+ info_ptr->cicp_transfer_function = transfer_function;
+ info_ptr->cicp_matrix_coefficients = matrix_coefficients;
+ info_ptr->cicp_video_full_range_flag = video_full_range_flag;
+
+ if (info_ptr->cicp_matrix_coefficients != 0)
+ {
+ png_warning(png_ptr, "Invalid cICP matrix coefficients");
+ return;
+ }
+
+ info_ptr->valid |= PNG_INFO_cICP;
+}
+#endif /* cICP */
+
+#ifdef PNG_cLLI_SUPPORTED
+void PNGFAPI
+png_set_cLLI_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
+ /* The values below are in cd/m2 (nits) and are scaled by 10,000; not
+ * 100,000 as in the case of png_fixed_point.
+ */
+ png_uint_32 maxCLL, png_uint_32 maxFALL)
+{
+ png_debug1(1, "in %s storage function", "cLLI");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ /* Check the light level range: */
+ if (maxCLL > 0x7FFFFFFFU || maxFALL > 0x7FFFFFFFU)
+ {
+ /* The limit is 200kcd/m2; somewhat bright but not inconceivable because
+ * human vision is said to run up to 100Mcd/m2. The sun is about 2Gcd/m2.
+ *
+ * The reference sRGB monitor is 80cd/m2 and the limit of PQ encoding is
+ * 2kcd/m2.
+ */
+ png_chunk_report(png_ptr, "cLLI light level exceeds PNG limit",
+ PNG_CHUNK_WRITE_ERROR);
+ return;
+ }
+
+ info_ptr->maxCLL = maxCLL;
+ info_ptr->maxFALL = maxFALL;
+ info_ptr->valid |= PNG_INFO_cLLI;
+}
+
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_cLLI(png_const_structrp png_ptr, png_inforp info_ptr,
+ double maxCLL, double maxFALL)
+{
+ png_set_cLLI_fixed(png_ptr, info_ptr,
+ png_fixed_ITU(png_ptr, maxCLL, "png_set_cLLI(maxCLL)"),
+ png_fixed_ITU(png_ptr, maxFALL, "png_set_cLLI(maxFALL)"));
+}
+# endif /* FLOATING_POINT */
+#endif /* cLLI */
+
+#ifdef PNG_mDCV_SUPPORTED
+static png_uint_16
+png_ITU_fixed_16(int *error, png_fixed_point v)
+{
+ /* Return a safe uint16_t value scaled according to the ITU H273 rules for
+ * 16-bit display chromaticities. Functions like the corresponding
+ * png_fixed() internal function with regard to errors: it's an error on
+ * write, a chunk_benign_error on read: See the definition of
+ * png_chunk_report in pngpriv.h.
+ */
+ v /= 2; /* rounds to 0 in C: avoids insignificant arithmetic errors */
+ if (v > 65535 || v < 0)
+ {
+ *error = 1;
+ return 0;
+ }
+
+ return (png_uint_16)/*SAFE*/v;
+}
+
+void PNGAPI
+png_set_mDCV_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_fixed_point white_x, png_fixed_point white_y,
+ png_fixed_point red_x, png_fixed_point red_y,
+ png_fixed_point green_x, png_fixed_point green_y,
+ png_fixed_point blue_x, png_fixed_point blue_y,
+ png_uint_32 maxDL,
+ png_uint_32 minDL)
+{
+ png_uint_16 rx, ry, gx, gy, bx, by, wx, wy;
+ int error;
+
+ png_debug1(1, "in %s storage function", "mDCV");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ /* Check the input values to ensure they are in the expected range: */
+ error = 0;
+ rx = png_ITU_fixed_16(&error, red_x);
+ ry = png_ITU_fixed_16(&error, red_y);
+ gx = png_ITU_fixed_16(&error, green_x);
+ gy = png_ITU_fixed_16(&error, green_y);
+ bx = png_ITU_fixed_16(&error, blue_x);
+ by = png_ITU_fixed_16(&error, blue_y);
+ wx = png_ITU_fixed_16(&error, white_x);
+ wy = png_ITU_fixed_16(&error, white_y);
+
+ if (error)
+ {
+ png_chunk_report(png_ptr,
+ "mDCV chromaticities outside representable range",
+ PNG_CHUNK_WRITE_ERROR);
+ return;
+ }
+
+ /* Check the light level range: */
+ if (maxDL > 0x7FFFFFFFU || minDL > 0x7FFFFFFFU)
+ {
+ /* The limit is 200kcd/m2; somewhat bright but not inconceivable because
+ * human vision is said to run up to 100Mcd/m2. The sun is about 2Gcd/m2.
+ *
+ * The reference sRGB monitor is 80cd/m2 and the limit of PQ encoding is
+ * 2kcd/m2.
+ */
+ png_chunk_report(png_ptr, "mDCV display light level exceeds PNG limit",
+ PNG_CHUNK_WRITE_ERROR);
+ return;
+ }
+
+ /* All values are safe, the settings are accepted.
+ *
+ * IMPLEMENTATION NOTE: in practice the values can be checked and assigned
+ * but the result is confusing if a writing app calls png_set_mDCV more than
+ * once, the second time with an invalid value. This approach is more
+ * obviously correct at the cost of typing and a very slight machine
+ * overhead.
+ */
+ info_ptr->mastering_red_x = rx;
+ info_ptr->mastering_red_y = ry;
+ info_ptr->mastering_green_x = gx;
+ info_ptr->mastering_green_y = gy;
+ info_ptr->mastering_blue_x = bx;
+ info_ptr->mastering_blue_y = by;
+ info_ptr->mastering_white_x = wx;
+ info_ptr->mastering_white_y = wy;
+ info_ptr->mastering_maxDL = maxDL;
+ info_ptr->mastering_minDL = minDL;
+ info_ptr->valid |= PNG_INFO_mDCV;
+}
+
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_mDCV(png_const_structrp png_ptr, png_inforp info_ptr,
+ double white_x, double white_y, double red_x, double red_y, double green_x,
+ double green_y, double blue_x, double blue_y,
+ double maxDL, double minDL)
+{
+ png_set_mDCV_fixed(png_ptr, info_ptr,
+ png_fixed(png_ptr, white_x, "png_set_mDCV(white(x))"),
+ png_fixed(png_ptr, white_y, "png_set_mDCV(white(y))"),
+ png_fixed(png_ptr, red_x, "png_set_mDCV(red(x))"),
+ png_fixed(png_ptr, red_y, "png_set_mDCV(red(y))"),
+ png_fixed(png_ptr, green_x, "png_set_mDCV(green(x))"),
+ png_fixed(png_ptr, green_y, "png_set_mDCV(green(y))"),
+ png_fixed(png_ptr, blue_x, "png_set_mDCV(blue(x))"),
+ png_fixed(png_ptr, blue_y, "png_set_mDCV(blue(y))"),
+ png_fixed_ITU(png_ptr, maxDL, "png_set_mDCV(maxDL)"),
+ png_fixed_ITU(png_ptr, minDL, "png_set_mDCV(minDL)"));
+}
+# endif /* FLOATING_POINT */
+#endif /* mDCV */
+
+#ifdef PNG_eXIf_SUPPORTED
+void PNGAPI
+png_set_eXIf(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_bytep exif)
+{
+ png_warning(png_ptr, "png_set_eXIf does not work; use png_set_eXIf_1");
+ PNG_UNUSED(info_ptr)
+ PNG_UNUSED(exif)
+}
+
+void PNGAPI
+png_set_eXIf_1(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_uint_32 num_exif, png_bytep exif)
+{
+ png_bytep new_exif;
+
+ png_debug1(1, "in %s storage function", "eXIf");
+
+ if (png_ptr == NULL || info_ptr == NULL ||
+ (png_ptr->mode & PNG_WROTE_eXIf) != 0)
+ return;
+
+ new_exif = png_voidcast(png_bytep, png_malloc_warn(png_ptr, num_exif));
+
+ if (new_exif == NULL)
+ {
+ png_warning(png_ptr, "Insufficient memory for eXIf chunk data");
+ return;
+ }
+
+ memcpy(new_exif, exif, (size_t)num_exif);
+
+ png_free_data(png_ptr, info_ptr, PNG_FREE_EXIF, 0);
+
+ info_ptr->num_exif = num_exif;
+ info_ptr->exif = new_exif;
+ info_ptr->free_me |= PNG_FREE_EXIF;
+ info_ptr->valid |= PNG_INFO_eXIf;
+}
+#endif /* eXIf */
+
+#ifdef PNG_gAMA_SUPPORTED
+void PNGFAPI
+png_set_gAMA_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_fixed_point file_gamma)
+{
+ png_debug1(1, "in %s storage function", "gAMA");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ info_ptr->gamma = file_gamma;
+ info_ptr->valid |= PNG_INFO_gAMA;
+}
+
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_gAMA(png_const_structrp png_ptr, png_inforp info_ptr, double file_gamma)
+{
+ png_set_gAMA_fixed(png_ptr, info_ptr, png_fixed(png_ptr, file_gamma,
+ "png_set_gAMA"));
+}
+# endif
+#endif
+
+#ifdef PNG_hIST_SUPPORTED
+void PNGAPI
+png_set_hIST(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_const_uint_16p hist)
+{
+ int i;
+
+ png_debug1(1, "in %s storage function", "hIST");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ if (info_ptr->num_palette == 0 || info_ptr->num_palette
+ > PNG_MAX_PALETTE_LENGTH)
+ {
+ png_warning(png_ptr,
+ "Invalid palette size, hIST allocation skipped");
+
+ return;
+ }
+
+ png_free_data(png_ptr, info_ptr, PNG_FREE_HIST, 0);
+
+ /* Changed from info->num_palette to PNG_MAX_PALETTE_LENGTH in
+ * version 1.2.1
+ */
+ info_ptr->hist = png_voidcast(png_uint_16p, png_malloc_warn(png_ptr,
+ PNG_MAX_PALETTE_LENGTH * (sizeof (png_uint_16))));
+
+ if (info_ptr->hist == NULL)
+ {
+ png_warning(png_ptr, "Insufficient memory for hIST chunk data");
+ return;
+ }
+
+ for (i = 0; i < info_ptr->num_palette; i++)
+ info_ptr->hist[i] = hist[i];
+
+ info_ptr->free_me |= PNG_FREE_HIST;
+ info_ptr->valid |= PNG_INFO_hIST;
+}
+#endif
+
+void PNGAPI
+png_set_IHDR(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_uint_32 width, png_uint_32 height, int bit_depth,
+ int color_type, int interlace_type, int compression_type,
+ int filter_type)
+{
+ png_debug1(1, "in %s storage function", "IHDR");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ info_ptr->width = width;
+ info_ptr->height = height;
+ info_ptr->bit_depth = (png_byte)bit_depth;
+ info_ptr->color_type = (png_byte)color_type;
+ info_ptr->compression_type = (png_byte)compression_type;
+ info_ptr->filter_type = (png_byte)filter_type;
+ info_ptr->interlace_type = (png_byte)interlace_type;
+
+ png_check_IHDR (png_ptr, info_ptr->width, info_ptr->height,
+ info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type,
+ info_ptr->compression_type, info_ptr->filter_type);
+
+ if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ info_ptr->channels = 1;
+
+ else if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ info_ptr->channels = 3;
+
+ else
+ info_ptr->channels = 1;
+
+ if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+ info_ptr->channels++;
+
+ info_ptr->pixel_depth = (png_byte)(info_ptr->channels * info_ptr->bit_depth);
+
+ info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width);
+}
+
+#ifdef PNG_oFFs_SUPPORTED
+void PNGAPI
+png_set_oFFs(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_int_32 offset_x, png_int_32 offset_y, int unit_type)
+{
+ png_debug1(1, "in %s storage function", "oFFs");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ info_ptr->x_offset = offset_x;
+ info_ptr->y_offset = offset_y;
+ info_ptr->offset_unit_type = (png_byte)unit_type;
+ info_ptr->valid |= PNG_INFO_oFFs;
+}
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+void PNGAPI
+png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type,
+ int nparams, png_const_charp units, png_charpp params)
+{
+ size_t length;
+ int i;
+
+ png_debug1(1, "in %s storage function", "pCAL");
+
+ if (png_ptr == NULL || info_ptr == NULL || purpose == NULL || units == NULL
+ || (nparams > 0 && params == NULL))
+ return;
+
+ length = strlen(purpose) + 1;
+ png_debug1(3, "allocating purpose for info (%lu bytes)",
+ (unsigned long)length);
+
+ /* TODO: validate format of calibration name and unit name */
+
+ /* Check that the type matches the specification. */
+ if (type < 0 || type > 3)
+ {
+ png_chunk_report(png_ptr, "Invalid pCAL equation type",
+ PNG_CHUNK_WRITE_ERROR);
+ return;
+ }
+
+ if (nparams < 0 || nparams > 255)
+ {
+ png_chunk_report(png_ptr, "Invalid pCAL parameter count",
+ PNG_CHUNK_WRITE_ERROR);
+ return;
+ }
+
+ /* Validate params[nparams] */
+ for (i=0; ipcal_purpose = png_voidcast(png_charp,
+ png_malloc_warn(png_ptr, length));
+
+ if (info_ptr->pcal_purpose == NULL)
+ {
+ png_chunk_report(png_ptr, "Insufficient memory for pCAL purpose",
+ PNG_CHUNK_WRITE_ERROR);
+ return;
+ }
+
+ memcpy(info_ptr->pcal_purpose, purpose, length);
+
+ info_ptr->free_me |= PNG_FREE_PCAL;
+
+ png_debug(3, "storing X0, X1, type, and nparams in info");
+ info_ptr->pcal_X0 = X0;
+ info_ptr->pcal_X1 = X1;
+ info_ptr->pcal_type = (png_byte)type;
+ info_ptr->pcal_nparams = (png_byte)nparams;
+
+ length = strlen(units) + 1;
+ png_debug1(3, "allocating units for info (%lu bytes)",
+ (unsigned long)length);
+
+ info_ptr->pcal_units = png_voidcast(png_charp,
+ png_malloc_warn(png_ptr, length));
+
+ if (info_ptr->pcal_units == NULL)
+ {
+ png_warning(png_ptr, "Insufficient memory for pCAL units");
+ return;
+ }
+
+ memcpy(info_ptr->pcal_units, units, length);
+
+ info_ptr->pcal_params = png_voidcast(png_charpp, png_malloc_warn(png_ptr,
+ (size_t)(((unsigned int)nparams + 1) * (sizeof (png_charp)))));
+
+ if (info_ptr->pcal_params == NULL)
+ {
+ png_warning(png_ptr, "Insufficient memory for pCAL params");
+ return;
+ }
+
+ memset(info_ptr->pcal_params, 0, ((unsigned int)nparams + 1) *
+ (sizeof (png_charp)));
+
+ for (i = 0; i < nparams; i++)
+ {
+ length = strlen(params[i]) + 1;
+ png_debug2(3, "allocating parameter %d for info (%lu bytes)", i,
+ (unsigned long)length);
+
+ info_ptr->pcal_params[i] = (png_charp)png_malloc_warn(png_ptr, length);
+
+ if (info_ptr->pcal_params[i] == NULL)
+ {
+ png_warning(png_ptr, "Insufficient memory for pCAL parameter");
+ return;
+ }
+
+ memcpy(info_ptr->pcal_params[i], params[i], length);
+ }
+
+ info_ptr->valid |= PNG_INFO_pCAL;
+}
+#endif
+
+#ifdef PNG_sCAL_SUPPORTED
+void PNGAPI
+png_set_sCAL_s(png_const_structrp png_ptr, png_inforp info_ptr,
+ int unit, png_const_charp swidth, png_const_charp sheight)
+{
+ size_t lengthw = 0, lengthh = 0;
+
+ png_debug1(1, "in %s storage function", "sCAL");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ /* Double check the unit (should never get here with an invalid
+ * unit unless this is an API call.)
+ */
+ if (unit != 1 && unit != 2)
+ png_error(png_ptr, "Invalid sCAL unit");
+
+ if (swidth == NULL || (lengthw = strlen(swidth)) == 0 ||
+ swidth[0] == 45 /* '-' */ || !png_check_fp_string(swidth, lengthw))
+ png_error(png_ptr, "Invalid sCAL width");
+
+ if (sheight == NULL || (lengthh = strlen(sheight)) == 0 ||
+ sheight[0] == 45 /* '-' */ || !png_check_fp_string(sheight, lengthh))
+ png_error(png_ptr, "Invalid sCAL height");
+
+ info_ptr->scal_unit = (png_byte)unit;
+
+ ++lengthw;
+
+ png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthw);
+
+ info_ptr->scal_s_width = png_voidcast(png_charp,
+ png_malloc_warn(png_ptr, lengthw));
+
+ if (info_ptr->scal_s_width == NULL)
+ {
+ png_warning(png_ptr, "Memory allocation failed while processing sCAL");
+
+ return;
+ }
+
+ memcpy(info_ptr->scal_s_width, swidth, lengthw);
+
+ ++lengthh;
+
+ png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthh);
+
+ info_ptr->scal_s_height = png_voidcast(png_charp,
+ png_malloc_warn(png_ptr, lengthh));
+
+ if (info_ptr->scal_s_height == NULL)
+ {
+ png_free(png_ptr, info_ptr->scal_s_width);
+ info_ptr->scal_s_width = NULL;
+
+ png_warning(png_ptr, "Memory allocation failed while processing sCAL");
+ return;
+ }
+
+ memcpy(info_ptr->scal_s_height, sheight, lengthh);
+
+ info_ptr->free_me |= PNG_FREE_SCAL;
+ info_ptr->valid |= PNG_INFO_sCAL;
+}
+
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_sCAL(png_const_structrp png_ptr, png_inforp info_ptr, int unit,
+ double width, double height)
+{
+ png_debug1(1, "in %s storage function", "sCAL");
+
+ /* Check the arguments. */
+ if (width <= 0)
+ png_warning(png_ptr, "Invalid sCAL width ignored");
+
+ else if (height <= 0)
+ png_warning(png_ptr, "Invalid sCAL height ignored");
+
+ else
+ {
+ /* Convert 'width' and 'height' to ASCII. */
+ char swidth[PNG_sCAL_MAX_DIGITS+1];
+ char sheight[PNG_sCAL_MAX_DIGITS+1];
+
+ png_ascii_from_fp(png_ptr, swidth, (sizeof swidth), width,
+ PNG_sCAL_PRECISION);
+ png_ascii_from_fp(png_ptr, sheight, (sizeof sheight), height,
+ PNG_sCAL_PRECISION);
+
+ png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight);
+ }
+}
+# endif
+
+# ifdef PNG_FIXED_POINT_SUPPORTED
+void PNGAPI
+png_set_sCAL_fixed(png_const_structrp png_ptr, png_inforp info_ptr, int unit,
+ png_fixed_point width, png_fixed_point height)
+{
+ png_debug1(1, "in %s storage function", "sCAL");
+
+ /* Check the arguments. */
+ if (width <= 0)
+ png_warning(png_ptr, "Invalid sCAL width ignored");
+
+ else if (height <= 0)
+ png_warning(png_ptr, "Invalid sCAL height ignored");
+
+ else
+ {
+ /* Convert 'width' and 'height' to ASCII. */
+ char swidth[PNG_sCAL_MAX_DIGITS+1];
+ char sheight[PNG_sCAL_MAX_DIGITS+1];
+
+ png_ascii_from_fixed(png_ptr, swidth, (sizeof swidth), width);
+ png_ascii_from_fixed(png_ptr, sheight, (sizeof sheight), height);
+
+ png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight);
+ }
+}
+# endif
+#endif
+
+#ifdef PNG_pHYs_SUPPORTED
+void PNGAPI
+png_set_pHYs(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_uint_32 res_x, png_uint_32 res_y, int unit_type)
+{
+ png_debug1(1, "in %s storage function", "pHYs");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ info_ptr->x_pixels_per_unit = res_x;
+ info_ptr->y_pixels_per_unit = res_y;
+ info_ptr->phys_unit_type = (png_byte)unit_type;
+ info_ptr->valid |= PNG_INFO_pHYs;
+}
+#endif
+
+void PNGAPI
+png_set_PLTE(png_structrp png_ptr, png_inforp info_ptr,
+ png_const_colorp palette, int num_palette)
+{
+
+ png_uint_32 max_palette_length;
+
+ png_debug1(1, "in %s storage function", "PLTE");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ max_palette_length = (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ?
+ (1 << info_ptr->bit_depth) : PNG_MAX_PALETTE_LENGTH;
+
+ if (num_palette < 0 || num_palette > (int) max_palette_length)
+ {
+ if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ png_error(png_ptr, "Invalid palette length");
+
+ else
+ {
+ png_warning(png_ptr, "Invalid palette length");
+
+ return;
+ }
+ }
+
+ if ((num_palette > 0 && palette == NULL) ||
+ (num_palette == 0
+# ifdef PNG_MNG_FEATURES_SUPPORTED
+ && (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0
+# endif
+ ))
+ {
+ png_error(png_ptr, "Invalid palette");
+ }
+
+ /* It may not actually be necessary to set png_ptr->palette here;
+ * we do it for backward compatibility with the way the png_handle_tRNS
+ * function used to do the allocation.
+ *
+ * 1.6.0: the above statement appears to be incorrect; something has to set
+ * the palette inside png_struct on read.
+ */
+ png_free_data(png_ptr, info_ptr, PNG_FREE_PLTE, 0);
+
+ /* Changed in libpng-1.2.1 to allocate PNG_MAX_PALETTE_LENGTH instead
+ * of num_palette entries, in case of an invalid PNG file or incorrect
+ * call to png_set_PLTE() with too-large sample values.
+ */
+ png_ptr->palette = png_voidcast(png_colorp, png_calloc(png_ptr,
+ PNG_MAX_PALETTE_LENGTH * (sizeof (png_color))));
+
+ if (num_palette > 0)
+ memcpy(png_ptr->palette, palette, (unsigned int)num_palette *
+ (sizeof (png_color)));
+
+ info_ptr->palette = png_ptr->palette;
+ info_ptr->num_palette = png_ptr->num_palette = (png_uint_16)num_palette;
+ info_ptr->free_me |= PNG_FREE_PLTE;
+ info_ptr->valid |= PNG_INFO_PLTE;
+}
+
+#ifdef PNG_sBIT_SUPPORTED
+void PNGAPI
+png_set_sBIT(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_const_color_8p sig_bit)
+{
+ png_debug1(1, "in %s storage function", "sBIT");
+
+ if (png_ptr == NULL || info_ptr == NULL || sig_bit == NULL)
+ return;
+
+ info_ptr->sig_bit = *sig_bit;
+ info_ptr->valid |= PNG_INFO_sBIT;
+}
+#endif
+
+#ifdef PNG_sRGB_SUPPORTED
+void PNGAPI
+png_set_sRGB(png_const_structrp png_ptr, png_inforp info_ptr, int srgb_intent)
+{
+ png_debug1(1, "in %s storage function", "sRGB");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ info_ptr->rendering_intent = srgb_intent;
+ info_ptr->valid |= PNG_INFO_sRGB;
+}
+
+void PNGAPI
+png_set_sRGB_gAMA_and_cHRM(png_const_structrp png_ptr, png_inforp info_ptr,
+ int srgb_intent)
+{
+ png_debug1(1, "in %s storage function", "sRGB_gAMA_and_cHRM");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ png_set_sRGB(png_ptr, info_ptr, srgb_intent);
+
+# ifdef PNG_gAMA_SUPPORTED
+ png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_sRGB_INVERSE);
+# endif /* gAMA */
+
+# ifdef PNG_cHRM_SUPPORTED
+ png_set_cHRM_fixed(png_ptr, info_ptr,
+ /* color x y */
+ /* white */ 31270, 32900,
+ /* red */ 64000, 33000,
+ /* green */ 30000, 60000,
+ /* blue */ 15000, 6000);
+# endif /* cHRM */
+}
+#endif /* sRGB */
+
+
+#ifdef PNG_iCCP_SUPPORTED
+void PNGAPI
+png_set_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_const_charp name, int compression_type,
+ png_const_bytep profile, png_uint_32 proflen)
+{
+ png_charp new_iccp_name;
+ png_bytep new_iccp_profile;
+ size_t length;
+
+ png_debug1(1, "in %s storage function", "iCCP");
+
+ if (png_ptr == NULL || info_ptr == NULL || name == NULL || profile == NULL)
+ return;
+
+ if (compression_type != PNG_COMPRESSION_TYPE_BASE)
+ png_app_error(png_ptr, "Invalid iCCP compression method");
+
+ length = strlen(name)+1;
+ new_iccp_name = png_voidcast(png_charp, png_malloc_warn(png_ptr, length));
+
+ if (new_iccp_name == NULL)
+ {
+ png_benign_error(png_ptr, "Insufficient memory to process iCCP chunk");
+
+ return;
+ }
+
+ memcpy(new_iccp_name, name, length);
+ new_iccp_profile = png_voidcast(png_bytep,
+ png_malloc_warn(png_ptr, proflen));
+
+ if (new_iccp_profile == NULL)
+ {
+ png_free(png_ptr, new_iccp_name);
+ png_benign_error(png_ptr,
+ "Insufficient memory to process iCCP profile");
+
+ return;
+ }
+
+ memcpy(new_iccp_profile, profile, proflen);
+
+ png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, 0);
+
+ info_ptr->iccp_proflen = proflen;
+ info_ptr->iccp_name = new_iccp_name;
+ info_ptr->iccp_profile = new_iccp_profile;
+ info_ptr->free_me |= PNG_FREE_ICCP;
+ info_ptr->valid |= PNG_INFO_iCCP;
+}
+#endif
+
+#ifdef PNG_TEXT_SUPPORTED
+void PNGAPI
+png_set_text(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_const_textp text_ptr, int num_text)
+{
+ int ret;
+ ret = png_set_text_2(png_ptr, info_ptr, text_ptr, num_text);
+
+ if (ret != 0)
+ png_error(png_ptr, "Insufficient memory to store text");
+}
+
+int /* PRIVATE */
+png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_const_textp text_ptr, int num_text)
+{
+ int i;
+
+ png_debug1(1, "in text storage function, chunk typeid = 0x%lx",
+ png_ptr == NULL ? 0xabadca11UL : (unsigned long)png_ptr->chunk_name);
+
+ if (png_ptr == NULL || info_ptr == NULL || num_text <= 0 || text_ptr == NULL)
+ return 0;
+
+ /* Make sure we have enough space in the "text" array in info_struct
+ * to hold all of the incoming text_ptr objects. This compare can't overflow
+ * because max_text >= num_text (anyway, subtract of two positive integers
+ * can't overflow in any case.)
+ */
+ if (num_text > info_ptr->max_text - info_ptr->num_text)
+ {
+ int old_num_text = info_ptr->num_text;
+ int max_text;
+ png_textp new_text = NULL;
+
+ /* Calculate an appropriate max_text, checking for overflow. */
+ max_text = old_num_text;
+ if (num_text <= INT_MAX - max_text)
+ {
+ max_text += num_text;
+
+ /* Round up to a multiple of 8 */
+ if (max_text < INT_MAX-8)
+ max_text = (max_text + 8) & ~0x7;
+
+ else
+ max_text = INT_MAX;
+
+ /* Now allocate a new array and copy the old members in; this does all
+ * the overflow checks.
+ */
+ new_text = png_voidcast(png_textp,png_realloc_array(png_ptr,
+ info_ptr->text, old_num_text, max_text-old_num_text,
+ sizeof *new_text));
+ }
+
+ if (new_text == NULL)
+ {
+ png_chunk_report(png_ptr, "too many text chunks",
+ PNG_CHUNK_WRITE_ERROR);
+
+ return 1;
+ }
+
+ png_free(png_ptr, info_ptr->text);
+
+ info_ptr->text = new_text;
+ info_ptr->free_me |= PNG_FREE_TEXT;
+ info_ptr->max_text = max_text;
+ /* num_text is adjusted below as the entries are copied in */
+
+ png_debug1(3, "allocated %d entries for info_ptr->text", max_text);
+ }
+
+ for (i = 0; i < num_text; i++)
+ {
+ size_t text_length, key_len;
+ size_t lang_len, lang_key_len;
+ png_textp textp = &(info_ptr->text[info_ptr->num_text]);
+
+ if (text_ptr[i].key == NULL)
+ continue;
+
+ if (text_ptr[i].compression < PNG_TEXT_COMPRESSION_NONE ||
+ text_ptr[i].compression >= PNG_TEXT_COMPRESSION_LAST)
+ {
+ png_chunk_report(png_ptr, "text compression mode is out of range",
+ PNG_CHUNK_WRITE_ERROR);
+ continue;
+ }
+
+ key_len = strlen(text_ptr[i].key);
+
+ if (text_ptr[i].compression <= 0)
+ {
+ lang_len = 0;
+ lang_key_len = 0;
+ }
+
+ else
+# ifdef PNG_iTXt_SUPPORTED
+ {
+ /* Set iTXt data */
+
+ if (text_ptr[i].lang != NULL)
+ lang_len = strlen(text_ptr[i].lang);
+
+ else
+ lang_len = 0;
+
+ if (text_ptr[i].lang_key != NULL)
+ lang_key_len = strlen(text_ptr[i].lang_key);
+
+ else
+ lang_key_len = 0;
+ }
+# else /* iTXt */
+ {
+ png_chunk_report(png_ptr, "iTXt chunk not supported",
+ PNG_CHUNK_WRITE_ERROR);
+ continue;
+ }
+# endif
+
+ if (text_ptr[i].text == NULL || text_ptr[i].text[0] == '\0')
+ {
+ text_length = 0;
+# ifdef PNG_iTXt_SUPPORTED
+ if (text_ptr[i].compression > 0)
+ textp->compression = PNG_ITXT_COMPRESSION_NONE;
+
+ else
+# endif
+ textp->compression = PNG_TEXT_COMPRESSION_NONE;
+ }
+
+ else
+ {
+ text_length = strlen(text_ptr[i].text);
+ textp->compression = text_ptr[i].compression;
+ }
+
+ textp->key = png_voidcast(png_charp,png_malloc_base(png_ptr,
+ key_len + text_length + lang_len + lang_key_len + 4));
+
+ if (textp->key == NULL)
+ {
+ png_chunk_report(png_ptr, "text chunk: out of memory",
+ PNG_CHUNK_WRITE_ERROR);
+
+ return 1;
+ }
+
+ png_debug2(2, "Allocated %lu bytes at %p in png_set_text",
+ (unsigned long)(png_uint_32)
+ (key_len + lang_len + lang_key_len + text_length + 4),
+ textp->key);
+
+ memcpy(textp->key, text_ptr[i].key, key_len);
+ *(textp->key + key_len) = '\0';
+
+ if (text_ptr[i].compression > 0)
+ {
+ textp->lang = textp->key + key_len + 1;
+ memcpy(textp->lang, text_ptr[i].lang, lang_len);
+ *(textp->lang + lang_len) = '\0';
+ textp->lang_key = textp->lang + lang_len + 1;
+ memcpy(textp->lang_key, text_ptr[i].lang_key, lang_key_len);
+ *(textp->lang_key + lang_key_len) = '\0';
+ textp->text = textp->lang_key + lang_key_len + 1;
+ }
+
+ else
+ {
+ textp->lang=NULL;
+ textp->lang_key=NULL;
+ textp->text = textp->key + key_len + 1;
+ }
+
+ if (text_length != 0)
+ memcpy(textp->text, text_ptr[i].text, text_length);
+
+ *(textp->text + text_length) = '\0';
+
+# ifdef PNG_iTXt_SUPPORTED
+ if (textp->compression > 0)
+ {
+ textp->text_length = 0;
+ textp->itxt_length = text_length;
+ }
+
+ else
+# endif
+ {
+ textp->text_length = text_length;
+ textp->itxt_length = 0;
+ }
+
+ info_ptr->num_text++;
+ png_debug1(3, "transferred text chunk %d", info_ptr->num_text);
+ }
+
+ return 0;
+}
+#endif
+
+#ifdef PNG_tIME_SUPPORTED
+void PNGAPI
+png_set_tIME(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_const_timep mod_time)
+{
+ png_debug1(1, "in %s storage function", "tIME");
+
+ if (png_ptr == NULL || info_ptr == NULL || mod_time == NULL ||
+ (png_ptr->mode & PNG_WROTE_tIME) != 0)
+ return;
+
+ if (mod_time->month == 0 || mod_time->month > 12 ||
+ mod_time->day == 0 || mod_time->day > 31 ||
+ mod_time->hour > 23 || mod_time->minute > 59 ||
+ mod_time->second > 60)
+ {
+ png_warning(png_ptr, "Ignoring invalid time value");
+
+ return;
+ }
+
+ info_ptr->mod_time = *mod_time;
+ info_ptr->valid |= PNG_INFO_tIME;
+}
+#endif
+
+#ifdef PNG_tRNS_SUPPORTED
+void PNGAPI
+png_set_tRNS(png_structrp png_ptr, png_inforp info_ptr,
+ png_const_bytep trans_alpha, int num_trans, png_const_color_16p trans_color)
+{
+ png_debug1(1, "in %s storage function", "tRNS");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+
+ return;
+
+ if (trans_alpha != NULL)
+ {
+ /* It may not actually be necessary to set png_ptr->trans_alpha here;
+ * we do it for backward compatibility with the way the png_handle_tRNS
+ * function used to do the allocation.
+ *
+ * 1.6.0: The above statement is incorrect; png_handle_tRNS effectively
+ * relies on png_set_tRNS storing the information in png_struct
+ * (otherwise it won't be there for the code in pngrtran.c).
+ */
+
+ png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0);
+
+ if (num_trans > 0 && num_trans <= PNG_MAX_PALETTE_LENGTH)
+ {
+ /* Changed from num_trans to PNG_MAX_PALETTE_LENGTH in version 1.2.1 */
+ info_ptr->trans_alpha = png_voidcast(png_bytep,
+ png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH));
+ memcpy(info_ptr->trans_alpha, trans_alpha, (size_t)num_trans);
+
+ info_ptr->free_me |= PNG_FREE_TRNS;
+ info_ptr->valid |= PNG_INFO_tRNS;
+ }
+ png_ptr->trans_alpha = info_ptr->trans_alpha;
+ }
+
+ if (trans_color != NULL)
+ {
+#ifdef PNG_WARNINGS_SUPPORTED
+ if (info_ptr->bit_depth < 16)
+ {
+ int sample_max = (1 << info_ptr->bit_depth) - 1;
+
+ if ((info_ptr->color_type == PNG_COLOR_TYPE_GRAY &&
+ trans_color->gray > sample_max) ||
+ (info_ptr->color_type == PNG_COLOR_TYPE_RGB &&
+ (trans_color->red > sample_max ||
+ trans_color->green > sample_max ||
+ trans_color->blue > sample_max)))
+ png_warning(png_ptr,
+ "tRNS chunk has out-of-range samples for bit_depth");
+ }
+#endif
+
+ info_ptr->trans_color = *trans_color;
+
+ if (num_trans == 0)
+ num_trans = 1;
+ }
+
+ info_ptr->num_trans = (png_uint_16)num_trans;
+
+ if (num_trans != 0)
+ {
+ info_ptr->free_me |= PNG_FREE_TRNS;
+ info_ptr->valid |= PNG_INFO_tRNS;
+ }
+}
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+void PNGAPI
+png_set_sPLT(png_const_structrp png_ptr,
+ png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)
+/*
+ * entries - array of png_sPLT_t structures
+ * to be added to the list of palettes
+ * in the info structure.
+ *
+ * nentries - number of palette structures to be
+ * added.
+ */
+{
+ png_sPLT_tp np;
+
+ png_debug1(1, "in %s storage function", "sPLT");
+
+ if (png_ptr == NULL || info_ptr == NULL || nentries <= 0 || entries == NULL)
+ return;
+
+ /* Use the internal realloc function, which checks for all the possible
+ * overflows. Notice that the parameters are (int) and (size_t)
+ */
+ np = png_voidcast(png_sPLT_tp,png_realloc_array(png_ptr,
+ info_ptr->splt_palettes, info_ptr->splt_palettes_num, nentries,
+ sizeof *np));
+
+ if (np == NULL)
+ {
+ /* Out of memory or too many chunks */
+ png_chunk_report(png_ptr, "too many sPLT chunks", PNG_CHUNK_WRITE_ERROR);
+ return;
+ }
+
+ png_free(png_ptr, info_ptr->splt_palettes);
+
+ info_ptr->splt_palettes = np;
+ info_ptr->free_me |= PNG_FREE_SPLT;
+
+ np += info_ptr->splt_palettes_num;
+
+ do
+ {
+ size_t length;
+
+ /* Skip invalid input entries */
+ if (entries->name == NULL || entries->entries == NULL)
+ {
+ /* png_handle_sPLT doesn't do this, so this is an app error */
+ png_app_error(png_ptr, "png_set_sPLT: invalid sPLT");
+ /* Just skip the invalid entry */
+ continue;
+ }
+
+ np->depth = entries->depth;
+
+ /* In the event of out-of-memory just return - there's no point keeping
+ * on trying to add sPLT chunks.
+ */
+ length = strlen(entries->name) + 1;
+ np->name = png_voidcast(png_charp, png_malloc_base(png_ptr, length));
+
+ if (np->name == NULL)
+ break;
+
+ memcpy(np->name, entries->name, length);
+
+ /* IMPORTANT: we have memory now that won't get freed if something else
+ * goes wrong; this code must free it. png_malloc_array produces no
+ * warnings; use a png_chunk_report (below) if there is an error.
+ */
+ np->entries = png_voidcast(png_sPLT_entryp, png_malloc_array(png_ptr,
+ entries->nentries, sizeof (png_sPLT_entry)));
+
+ if (np->entries == NULL)
+ {
+ png_free(png_ptr, np->name);
+ np->name = NULL;
+ break;
+ }
+
+ np->nentries = entries->nentries;
+ /* This multiply can't overflow because png_malloc_array has already
+ * checked it when doing the allocation.
+ */
+ memcpy(np->entries, entries->entries,
+ (unsigned int)entries->nentries * sizeof (png_sPLT_entry));
+
+ /* Note that 'continue' skips the advance of the out pointer and out
+ * count, so an invalid entry is not added.
+ */
+ info_ptr->valid |= PNG_INFO_sPLT;
+ ++(info_ptr->splt_palettes_num);
+ ++np;
+ ++entries;
+ }
+ while (--nentries);
+
+ if (nentries > 0)
+ png_chunk_report(png_ptr, "sPLT out of memory", PNG_CHUNK_WRITE_ERROR);
+}
+#endif /* sPLT */
+
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+static png_byte
+check_location(png_const_structrp png_ptr, int location)
+{
+ location &= (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT);
+
+ /* New in 1.6.0; copy the location and check it. This is an API
+ * change; previously the app had to use the
+ * png_set_unknown_chunk_location API below for each chunk.
+ */
+ if (location == 0 && (png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
+ {
+ /* Write struct, so unknown chunks come from the app */
+ png_app_warning(png_ptr,
+ "png_set_unknown_chunks now expects a valid location");
+ /* Use the old behavior */
+ location = (png_byte)(png_ptr->mode &
+ (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT));
+ }
+
+ /* This need not be an internal error - if the app calls
+ * png_set_unknown_chunks on a read pointer it must get the location right.
+ */
+ if (location == 0)
+ png_error(png_ptr, "invalid location in png_set_unknown_chunks");
+
+ /* Now reduce the location to the top-most set bit by removing each least
+ * significant bit in turn.
+ */
+ while (location != (location & -location))
+ location &= ~(location & -location);
+
+ /* The cast is safe because 'location' is a bit mask and only the low four
+ * bits are significant.
+ */
+ return (png_byte)location;
+}
+
+void PNGAPI
+png_set_unknown_chunks(png_const_structrp png_ptr,
+ png_inforp info_ptr, png_const_unknown_chunkp unknowns, int num_unknowns)
+{
+ png_unknown_chunkp np;
+
+ if (png_ptr == NULL || info_ptr == NULL || num_unknowns <= 0 ||
+ unknowns == NULL)
+ return;
+
+ /* Check for the failure cases where support has been disabled at compile
+ * time. This code is hardly ever compiled - it's here because
+ * STORE_UNKNOWN_CHUNKS is set by both read and write code (compiling in this
+ * code) but may be meaningless if the read or write handling of unknown
+ * chunks is not compiled in.
+ */
+# if !defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) && \
+ defined(PNG_READ_SUPPORTED)
+ if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
+ {
+ png_app_error(png_ptr, "no unknown chunk support on read");
+
+ return;
+ }
+# endif
+# if !defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED) && \
+ defined(PNG_WRITE_SUPPORTED)
+ if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
+ {
+ png_app_error(png_ptr, "no unknown chunk support on write");
+
+ return;
+ }
+# endif
+
+ /* Prior to 1.6.0 this code used png_malloc_warn; however, this meant that
+ * unknown critical chunks could be lost with just a warning resulting in
+ * undefined behavior. Now png_chunk_report is used to provide behavior
+ * appropriate to read or write.
+ */
+ np = png_voidcast(png_unknown_chunkp, png_realloc_array(png_ptr,
+ info_ptr->unknown_chunks, info_ptr->unknown_chunks_num, num_unknowns,
+ sizeof *np));
+
+ if (np == NULL)
+ {
+ png_chunk_report(png_ptr, "too many unknown chunks",
+ PNG_CHUNK_WRITE_ERROR);
+ return;
+ }
+
+ png_free(png_ptr, info_ptr->unknown_chunks);
+
+ info_ptr->unknown_chunks = np; /* safe because it is initialized */
+ info_ptr->free_me |= PNG_FREE_UNKN;
+
+ np += info_ptr->unknown_chunks_num;
+
+ /* Increment unknown_chunks_num each time round the loop to protect the
+ * just-allocated chunk data.
+ */
+ for (; num_unknowns > 0; --num_unknowns, ++unknowns)
+ {
+ memcpy(np->name, unknowns->name, (sizeof np->name));
+ np->name[(sizeof np->name)-1] = '\0';
+ np->location = check_location(png_ptr, unknowns->location);
+
+ if (unknowns->size == 0)
+ {
+ np->data = NULL;
+ np->size = 0;
+ }
+
+ else
+ {
+ np->data = png_voidcast(png_bytep,
+ png_malloc_base(png_ptr, unknowns->size));
+
+ if (np->data == NULL)
+ {
+ png_chunk_report(png_ptr, "unknown chunk: out of memory",
+ PNG_CHUNK_WRITE_ERROR);
+ /* But just skip storing the unknown chunk */
+ continue;
+ }
+
+ memcpy(np->data, unknowns->data, unknowns->size);
+ np->size = unknowns->size;
+ }
+
+ /* These increments are skipped on out-of-memory for the data - the
+ * unknown chunk entry gets overwritten if the png_chunk_report returns.
+ * This is correct in the read case (the chunk is just dropped.)
+ */
+ ++np;
+ ++(info_ptr->unknown_chunks_num);
+ }
+}
+
+void PNGAPI
+png_set_unknown_chunk_location(png_const_structrp png_ptr, png_inforp info_ptr,
+ int chunk, int location)
+{
+ /* This API is pretty pointless in 1.6.0 because the location can be set
+ * before the call to png_set_unknown_chunks.
+ *
+ * TODO: add a png_app_warning in 1.7
+ */
+ if (png_ptr != NULL && info_ptr != NULL && chunk >= 0 &&
+ chunk < info_ptr->unknown_chunks_num)
+ {
+ if ((location & (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT)) == 0)
+ {
+ png_app_error(png_ptr, "invalid unknown chunk location");
+ /* Fake out the pre 1.6.0 behavior: */
+ if (((unsigned int)location & PNG_HAVE_IDAT) != 0) /* undocumented! */
+ location = PNG_AFTER_IDAT;
+
+ else
+ location = PNG_HAVE_IHDR; /* also undocumented */
+ }
+
+ info_ptr->unknown_chunks[chunk].location =
+ check_location(png_ptr, location);
+ }
+}
+#endif /* STORE_UNKNOWN_CHUNKS */
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+png_uint_32 PNGAPI
+png_permit_mng_features(png_structrp png_ptr, png_uint_32 mng_features)
+{
+ png_debug(1, "in png_permit_mng_features");
+
+ if (png_ptr == NULL)
+ return 0;
+
+ png_ptr->mng_features_permitted = mng_features & PNG_ALL_MNG_FEATURES;
+
+ return png_ptr->mng_features_permitted;
+}
+#endif
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+static unsigned int
+add_one_chunk(png_bytep list, unsigned int count, png_const_bytep add, int keep)
+{
+ unsigned int i;
+
+ /* Utility function: update the 'keep' state of a chunk if it is already in
+ * the list, otherwise add it to the list.
+ */
+ for (i=0; i= PNG_HANDLE_CHUNK_LAST)
+ {
+ png_app_error(png_ptr, "png_set_keep_unknown_chunks: invalid keep");
+
+ return;
+ }
+
+ if (num_chunks_in <= 0)
+ {
+ png_ptr->unknown_default = keep;
+
+ /* '0' means just set the flags, so stop here */
+ if (num_chunks_in == 0)
+ return;
+ }
+
+ if (num_chunks_in < 0)
+ {
+ /* Ignore all unknown chunks and all chunks recognized by
+ * libpng except for IHDR, PLTE, tRNS, IDAT, and IEND
+ */
+ static const png_byte chunks_to_ignore[] = {
+ 98, 75, 71, 68, '\0', /* bKGD */
+ 99, 72, 82, 77, '\0', /* cHRM */
+ 99, 73, 67, 80, '\0', /* cICP */
+ 99, 76, 76, 73, '\0', /* cLLI */
+ 101, 88, 73, 102, '\0', /* eXIf */
+ 103, 65, 77, 65, '\0', /* gAMA */
+ 104, 73, 83, 84, '\0', /* hIST */
+ 105, 67, 67, 80, '\0', /* iCCP */
+ 105, 84, 88, 116, '\0', /* iTXt */
+ 109, 68, 67, 86, '\0', /* mDCV */
+ 111, 70, 70, 115, '\0', /* oFFs */
+ 112, 67, 65, 76, '\0', /* pCAL */
+ 112, 72, 89, 115, '\0', /* pHYs */
+ 115, 66, 73, 84, '\0', /* sBIT */
+ 115, 67, 65, 76, '\0', /* sCAL */
+ 115, 80, 76, 84, '\0', /* sPLT */
+ 115, 84, 69, 82, '\0', /* sTER */
+ 115, 82, 71, 66, '\0', /* sRGB */
+ 116, 69, 88, 116, '\0', /* tEXt */
+ 116, 73, 77, 69, '\0', /* tIME */
+ 122, 84, 88, 116, '\0' /* zTXt */
+ };
+
+ chunk_list = chunks_to_ignore;
+ num_chunks = (unsigned int)/*SAFE*/(sizeof chunks_to_ignore)/5U;
+ }
+
+ else /* num_chunks_in > 0 */
+ {
+ if (chunk_list == NULL)
+ {
+ /* Prior to 1.6.0 this was silently ignored, now it is an app_error
+ * which can be switched off.
+ */
+ png_app_error(png_ptr, "png_set_keep_unknown_chunks: no chunk list");
+
+ return;
+ }
+
+ num_chunks = (unsigned int)num_chunks_in;
+ }
+
+ old_num_chunks = png_ptr->num_chunk_list;
+ if (png_ptr->chunk_list == NULL)
+ old_num_chunks = 0;
+
+ /* Since num_chunks is always restricted to UINT_MAX/5 this can't overflow.
+ */
+ if (num_chunks + old_num_chunks > UINT_MAX/5)
+ {
+ png_app_error(png_ptr, "png_set_keep_unknown_chunks: too many chunks");
+
+ return;
+ }
+
+ /* If these chunks are being reset to the default then no more memory is
+ * required because add_one_chunk above doesn't extend the list if the 'keep'
+ * parameter is the default.
+ */
+ if (keep != 0)
+ {
+ new_list = png_voidcast(png_bytep, png_malloc(png_ptr,
+ 5 * (num_chunks + old_num_chunks)));
+
+ if (old_num_chunks > 0)
+ memcpy(new_list, png_ptr->chunk_list, 5*old_num_chunks);
+ }
+
+ else if (old_num_chunks > 0)
+ new_list = png_ptr->chunk_list;
+
+ else
+ new_list = NULL;
+
+ /* Add the new chunks together with each one's handling code. If the chunk
+ * already exists the code is updated, otherwise the chunk is added to the
+ * end. (In libpng 1.6.0 order no longer matters because this code enforces
+ * the earlier convention that the last setting is the one that is used.)
+ */
+ if (new_list != NULL)
+ {
+ png_const_bytep inlist;
+ png_bytep outlist;
+ unsigned int i;
+
+ for (i=0; ichunk_list != new_list)
+ png_free(png_ptr, new_list);
+
+ new_list = NULL;
+ }
+ }
+
+ else
+ num_chunks = 0;
+
+ png_ptr->num_chunk_list = num_chunks;
+
+ if (png_ptr->chunk_list != new_list)
+ {
+ if (png_ptr->chunk_list != NULL)
+ png_free(png_ptr, png_ptr->chunk_list);
+
+ png_ptr->chunk_list = new_list;
+ }
+}
+#endif
+
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+void PNGAPI
+png_set_read_user_chunk_fn(png_structrp png_ptr, png_voidp user_chunk_ptr,
+ png_user_chunk_ptr read_user_chunk_fn)
+{
+ png_debug(1, "in png_set_read_user_chunk_fn");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->read_user_chunk_fn = read_user_chunk_fn;
+ png_ptr->user_chunk_ptr = user_chunk_ptr;
+}
+#endif
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+void PNGAPI
+png_set_rows(png_const_structrp png_ptr, png_inforp info_ptr,
+ png_bytepp row_pointers)
+{
+ png_debug(1, "in png_set_rows");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ if (info_ptr->row_pointers != NULL &&
+ (info_ptr->row_pointers != row_pointers))
+ png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
+
+ info_ptr->row_pointers = row_pointers;
+
+ if (row_pointers != NULL)
+ info_ptr->valid |= PNG_INFO_IDAT;
+}
+#endif
+
+void PNGAPI
+png_set_compression_buffer_size(png_structrp png_ptr, size_t size)
+{
+ png_debug(1, "in png_set_compression_buffer_size");
+
+ if (png_ptr == NULL)
+ return;
+
+ if (size == 0 || size > PNG_UINT_31_MAX)
+ png_error(png_ptr, "invalid compression buffer size");
+
+# ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+ if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
+ {
+ png_ptr->IDAT_read_size = (png_uint_32)size; /* checked above */
+ return;
+ }
+# endif
+
+# ifdef PNG_WRITE_SUPPORTED
+ if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
+ {
+ if (png_ptr->zowner != 0)
+ {
+ png_warning(png_ptr,
+ "Compression buffer size cannot be changed because it is in use");
+
+ return;
+ }
+
+#ifndef __COVERITY__
+ /* Some compilers complain that this is always false. However, it
+ * can be true when integer overflow happens.
+ */
+ if (size > ZLIB_IO_MAX)
+ {
+ png_warning(png_ptr,
+ "Compression buffer size limited to system maximum");
+ size = ZLIB_IO_MAX; /* must fit */
+ }
+#endif
+
+ if (size < 6)
+ {
+ /* Deflate will potentially go into an infinite loop on a SYNC_FLUSH
+ * if this is permitted.
+ */
+ png_warning(png_ptr,
+ "Compression buffer size cannot be reduced below 6");
+
+ return;
+ }
+
+ if (png_ptr->zbuffer_size != size)
+ {
+ png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list);
+ png_ptr->zbuffer_size = (uInt)size;
+ }
+ }
+# endif
+}
+
+void PNGAPI
+png_set_invalid(png_const_structrp png_ptr, png_inforp info_ptr, int mask)
+{
+ if (png_ptr != NULL && info_ptr != NULL)
+ info_ptr->valid &= (unsigned int)(~mask);
+}
+
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+/* This function was added to libpng 1.2.6 */
+void PNGAPI
+png_set_user_limits(png_structrp png_ptr, png_uint_32 user_width_max,
+ png_uint_32 user_height_max)
+{
+ png_debug(1, "in png_set_user_limits");
+
+ /* Images with dimensions larger than these limits will be
+ * rejected by png_set_IHDR(). To accept any PNG datastream
+ * regardless of dimensions, set both limits to 0x7fffffff.
+ */
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->user_width_max = user_width_max;
+ png_ptr->user_height_max = user_height_max;
+}
+
+/* This function was added to libpng 1.4.0 */
+void PNGAPI
+png_set_chunk_cache_max(png_structrp png_ptr, png_uint_32 user_chunk_cache_max)
+{
+ png_debug(1, "in png_set_chunk_cache_max");
+
+ if (png_ptr != NULL)
+ png_ptr->user_chunk_cache_max = user_chunk_cache_max;
+}
+
+/* This function was added to libpng 1.4.1 */
+void PNGAPI
+png_set_chunk_malloc_max(png_structrp png_ptr,
+ png_alloc_size_t user_chunk_malloc_max)
+{
+ png_debug(1, "in png_set_chunk_malloc_max");
+
+ /* pngstruct::user_chunk_malloc_max is initialized to a non-zero value in
+ * png.c. This API supports '0' for unlimited, make sure the correct
+ * (unlimited) value is set here to avoid a need to check for 0 everywhere
+ * the parameter is used.
+ */
+ if (png_ptr != NULL)
+ {
+ if (user_chunk_malloc_max == 0U) /* unlimited */
+ {
+# ifdef PNG_MAX_MALLOC_64K
+ png_ptr->user_chunk_malloc_max = 65536U;
+# else
+ png_ptr->user_chunk_malloc_max = PNG_SIZE_MAX;
+# endif
+ }
+ else
+ png_ptr->user_chunk_malloc_max = user_chunk_malloc_max;
+ }
+}
+#endif /* ?SET_USER_LIMITS */
+
+
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+void PNGAPI
+png_set_benign_errors(png_structrp png_ptr, int allowed)
+{
+ png_debug(1, "in png_set_benign_errors");
+
+ /* If allowed is 1, png_benign_error() is treated as a warning.
+ *
+ * If allowed is 0, png_benign_error() is treated as an error (which
+ * is the default behavior if png_set_benign_errors() is not called).
+ */
+
+ if (allowed != 0)
+ png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN |
+ PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN;
+
+ else
+ png_ptr->flags &= ~(PNG_FLAG_BENIGN_ERRORS_WARN |
+ PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN);
+}
+#endif /* BENIGN_ERRORS */
+
+#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+ /* Whether to report invalid palette index; added at libng-1.5.10.
+ * It is possible for an indexed (color-type==3) PNG file to contain
+ * pixels with invalid (out-of-range) indexes if the PLTE chunk has
+ * fewer entries than the image's bit-depth would allow. We recover
+ * from this gracefully by filling any incomplete palette with zeros
+ * (opaque black). By default, when this occurs libpng will issue
+ * a benign error. This API can be used to override that behavior.
+ */
+void PNGAPI
+png_set_check_for_invalid_index(png_structrp png_ptr, int allowed)
+{
+ png_debug(1, "in png_set_check_for_invalid_index");
+
+ if (allowed > 0)
+ png_ptr->num_palette_max = 0;
+
+ else
+ png_ptr->num_palette_max = -1;
+}
+#endif
+
+#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_pCAL_SUPPORTED) || \
+ defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
+/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
+ * and if invalid, correct the keyword rather than discarding the entire
+ * chunk. The PNG 1.0 specification requires keywords 1-79 characters in
+ * length, forbids leading or trailing whitespace, multiple internal spaces,
+ * and the non-break space (0x80) from ISO 8859-1. Returns keyword length.
+ *
+ * The 'new_key' buffer must be 80 characters in size (for the keyword plus a
+ * trailing '\0'). If this routine returns 0 then there was no keyword, or a
+ * valid one could not be generated, and the caller must png_error.
+ */
+png_uint_32 /* PRIVATE */
+png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key)
+{
+#ifdef PNG_WARNINGS_SUPPORTED
+ png_const_charp orig_key = key;
+#endif
+ png_uint_32 key_len = 0;
+ int bad_character = 0;
+ int space = 1;
+
+ png_debug(1, "in png_check_keyword");
+
+ if (key == NULL)
+ {
+ *new_key = 0;
+ return 0;
+ }
+
+ while (*key && key_len < 79)
+ {
+ png_byte ch = (png_byte)*key++;
+
+ if ((ch > 32 && ch <= 126) || (ch >= 161 /*&& ch <= 255*/))
+ {
+ *new_key++ = ch; ++key_len; space = 0;
+ }
+
+ else if (space == 0)
+ {
+ /* A space or an invalid character when one wasn't seen immediately
+ * before; output just a space.
+ */
+ *new_key++ = 32; ++key_len; space = 1;
+
+ /* If the character was not a space then it is invalid. */
+ if (ch != 32)
+ bad_character = ch;
+ }
+
+ else if (bad_character == 0)
+ bad_character = ch; /* just skip it, record the first error */
+ }
+
+ if (key_len > 0 && space != 0) /* trailing space */
+ {
+ --key_len; --new_key;
+ if (bad_character == 0)
+ bad_character = 32;
+ }
+
+ /* Terminate the keyword */
+ *new_key = 0;
+
+ if (key_len == 0)
+ return 0;
+
+#ifdef PNG_WARNINGS_SUPPORTED
+ /* Try to only output one warning per keyword: */
+ if (*key != 0) /* keyword too long */
+ png_warning(png_ptr, "keyword truncated");
+
+ else if (bad_character != 0)
+ {
+ PNG_WARNING_PARAMETERS(p)
+
+ png_warning_parameter(p, 1, orig_key);
+ png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_02x, bad_character);
+
+ png_formatted_warning(png_ptr, p, "keyword \"@1\": bad character '0x@2'");
+ }
+#else /* !WARNINGS */
+ PNG_UNUSED(png_ptr)
+#endif /* !WARNINGS */
+
+ return key_len;
+}
+#endif /* TEXT || pCAL || iCCP || sPLT */
+#endif /* READ || WRITE */
diff --git a/libs/imagequant/external/libpng/pngstruct.h b/libs/imagequant/external/libpng/pngstruct.h
new file mode 100644
index 00000000..084422bc
--- /dev/null
+++ b/libs/imagequant/external/libpng/pngstruct.h
@@ -0,0 +1,465 @@
+/* pngstruct.h - internal structures for libpng
+ *
+ * Copyright (c) 2018-2025 Cosmin Truta
+ * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#ifndef PNGPRIV_H
+# error This file must not be included by applications; please include
+#endif
+
+#ifndef PNGSTRUCT_H
+#define PNGSTRUCT_H
+/* zlib.h defines the structure z_stream, an instance of which is included
+ * in this structure and is required for decompressing the LZ compressed
+ * data in PNG files.
+ */
+#ifndef ZLIB_CONST
+ /* We must ensure that zlib uses 'const' in declarations. */
+# define ZLIB_CONST
+#endif
+#include "zlib.h"
+#ifdef const
+ /* zlib.h sometimes #defines const to nothing, undo this. */
+# undef const
+#endif
+
+/* zlib.h has mediocre z_const use before 1.2.6, this stuff is for compatibility
+ * with older builds.
+ */
+#if ZLIB_VERNUM < 0x1260
+# define PNGZ_MSG_CAST(s) png_constcast(char*,s)
+# define PNGZ_INPUT_CAST(b) png_constcast(png_bytep,b)
+#else
+# define PNGZ_MSG_CAST(s) (s)
+# define PNGZ_INPUT_CAST(b) (b)
+#endif
+
+/* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib
+ * can handle at once. This type need be no larger than 16 bits (so maximum of
+ * 65535), this define allows us to discover how big it is, but limited by the
+ * maximum for size_t. The value can be overridden in a library build
+ * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably
+ * lower value (e.g. 255 works). A lower value may help memory usage (slightly)
+ * and may even improve performance on some systems (and degrade it on others.)
+ */
+#ifndef ZLIB_IO_MAX
+# define ZLIB_IO_MAX ((uInt)-1)
+#endif
+
+#ifdef PNG_WRITE_SUPPORTED
+/* The type of a compression buffer list used by the write code. */
+typedef struct png_compression_buffer
+{
+ struct png_compression_buffer *next;
+ png_byte output[1]; /* actually zbuf_size */
+} png_compression_buffer, *png_compression_bufferp;
+
+#define PNG_COMPRESSION_BUFFER_SIZE(pp)\
+ (offsetof(png_compression_buffer, output) + (pp)->zbuffer_size)
+#endif
+
+/* Colorspace support; structures used in png_struct, png_info and in internal
+ * functions to hold and communicate information about the color space.
+ */
+/* The chromaticities of the red, green and blue colorants and the chromaticity
+ * of the corresponding white point (i.e. of rgb(1.0,1.0,1.0)).
+ */
+typedef struct png_xy
+{
+ png_fixed_point redx, redy;
+ png_fixed_point greenx, greeny;
+ png_fixed_point bluex, bluey;
+ png_fixed_point whitex, whitey;
+} png_xy;
+
+/* The same data as above but encoded as CIE XYZ values. When this data comes
+ * from chromaticities the sum of the Y values is assumed to be 1.0
+ */
+typedef struct png_XYZ
+{
+ png_fixed_point red_X, red_Y, red_Z;
+ png_fixed_point green_X, green_Y, green_Z;
+ png_fixed_point blue_X, blue_Y, blue_Z;
+} png_XYZ;
+
+/* Chunk index values as an enum, PNG_INDEX_unknown is also a count of the
+ * number of chunks.
+ */
+#define PNG_CHUNK(cHNK, i) PNG_INDEX_ ## cHNK = (i),
+typedef enum
+{
+ PNG_KNOWN_CHUNKS
+ PNG_INDEX_unknown
+} png_index;
+#undef PNG_CHUNK
+
+/* Chunk flag values. These are (png_uint_32 values) with exactly one bit set
+ * and can be combined into a flag set with bitwise 'or'.
+ *
+ * TODO: C23: convert these macros to C23 inlines (which are static).
+ */
+#define png_chunk_flag_from_index(i) (0x80000000U >> (31 - (i)))
+ /* The flag coresponding to the given png_index enum value. This is defined
+ * for png_unknown as well (until it reaches the value 32) but this should
+ * not be relied on.
+ */
+
+#define png_file_has_chunk(png_ptr, i)\
+ (((png_ptr)->chunks & png_chunk_flag_from_index(i)) != 0)
+ /* The chunk has been recorded in png_struct */
+
+#define png_file_add_chunk(pnt_ptr, i)\
+ ((void)((png_ptr)->chunks |= png_chunk_flag_from_index(i)))
+ /* Record the chunk in the png_struct */
+
+struct png_struct_def
+{
+#ifdef PNG_SETJMP_SUPPORTED
+ jmp_buf jmp_buf_local; /* New name in 1.6.0 for jmp_buf in png_struct */
+ png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */
+ jmp_buf *jmp_buf_ptr; /* passed to longjmp_fn */
+ size_t jmp_buf_size; /* size of the above, if allocated */
+#endif
+ png_error_ptr error_fn; /* function for printing errors and aborting */
+#ifdef PNG_WARNINGS_SUPPORTED
+ png_error_ptr warning_fn; /* function for printing warnings */
+#endif
+ png_voidp error_ptr; /* user supplied struct for error functions */
+ png_rw_ptr write_data_fn; /* function for writing output data */
+ png_rw_ptr read_data_fn; /* function for reading input data */
+ png_voidp io_ptr; /* ptr to application struct for I/O functions */
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+ png_user_transform_ptr read_user_transform_fn; /* user read transform */
+#endif
+
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+ png_user_transform_ptr write_user_transform_fn; /* user write transform */
+#endif
+
+/* These were added in libpng-1.0.2 */
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+ png_voidp user_transform_ptr; /* user supplied struct for user transform */
+ png_byte user_transform_depth; /* bit depth of user transformed pixels */
+ png_byte user_transform_channels; /* channels in user transformed pixels */
+#endif
+#endif
+
+ png_uint_32 mode; /* tells us where we are in the PNG file */
+ png_uint_32 flags; /* flags indicating various things to libpng */
+ png_uint_32 transformations; /* which transformations to perform */
+
+ png_uint_32 zowner; /* ID (chunk type) of zstream owner, 0 if none */
+ z_stream zstream; /* decompression structure */
+
+#ifdef PNG_WRITE_SUPPORTED
+ png_compression_bufferp zbuffer_list; /* Created on demand during write */
+ uInt zbuffer_size; /* size of the actual buffer */
+
+ int zlib_level; /* holds zlib compression level */
+ int zlib_method; /* holds zlib compression method */
+ int zlib_window_bits; /* holds zlib compression window bits */
+ int zlib_mem_level; /* holds zlib compression memory level */
+ int zlib_strategy; /* holds zlib compression strategy */
+#endif
+/* Added at libpng 1.5.4 */
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+ int zlib_text_level; /* holds zlib compression level */
+ int zlib_text_method; /* holds zlib compression method */
+ int zlib_text_window_bits; /* holds zlib compression window bits */
+ int zlib_text_mem_level; /* holds zlib compression memory level */
+ int zlib_text_strategy; /* holds zlib compression strategy */
+#endif
+/* End of material added at libpng 1.5.4 */
+/* Added at libpng 1.6.0 */
+#ifdef PNG_WRITE_SUPPORTED
+ int zlib_set_level; /* Actual values set into the zstream on write */
+ int zlib_set_method;
+ int zlib_set_window_bits;
+ int zlib_set_mem_level;
+ int zlib_set_strategy;
+#endif
+
+ png_uint_32 chunks; /* PNG_CF_ for every chunk read or (NYI) written */
+# define png_has_chunk(png_ptr, cHNK)\
+ png_file_has_chunk(png_ptr, PNG_INDEX_ ## cHNK)
+ /* Convenience accessor - use this to check for a known chunk by name */
+
+ png_uint_32 width; /* width of image in pixels */
+ png_uint_32 height; /* height of image in pixels */
+ png_uint_32 num_rows; /* number of rows in current pass */
+ png_uint_32 usr_width; /* width of row at start of write */
+ size_t rowbytes; /* size of row in bytes */
+ png_uint_32 iwidth; /* width of current interlaced row in pixels */
+ png_uint_32 row_number; /* current row in interlace pass */
+ png_uint_32 chunk_name; /* PNG_CHUNK() id of current chunk */
+ png_bytep prev_row; /* buffer to save previous (unfiltered) row.
+ * While reading this is a pointer into
+ * big_prev_row; while writing it is separately
+ * allocated if needed.
+ */
+ png_bytep row_buf; /* buffer to save current (unfiltered) row.
+ * While reading, this is a pointer into
+ * big_row_buf; while writing it is separately
+ * allocated.
+ */
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ png_bytep try_row; /* buffer to save trial row when filtering */
+ png_bytep tst_row; /* buffer to save best trial row when filtering */
+#endif
+ size_t info_rowbytes; /* Added in 1.5.4: cache of updated row bytes */
+
+ png_uint_32 idat_size; /* current IDAT size for read */
+ png_uint_32 crc; /* current chunk CRC value */
+ png_colorp palette; /* palette from the input file */
+ png_uint_16 num_palette; /* number of color entries in palette */
+
+/* Added at libpng-1.5.10 */
+#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+ int num_palette_max; /* maximum palette index found in IDAT */
+#endif
+
+ png_uint_16 num_trans; /* number of transparency values */
+ png_byte compression; /* file compression type (always 0) */
+ png_byte filter; /* file filter type (always 0) */
+ png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
+ png_byte pass; /* current interlace pass (0 - 6) */
+ png_byte do_filter; /* row filter flags (see PNG_FILTER_ in png.h ) */
+ png_byte color_type; /* color type of file */
+ png_byte bit_depth; /* bit depth of file */
+ png_byte usr_bit_depth; /* bit depth of users row: write only */
+ png_byte pixel_depth; /* number of bits per pixel */
+ png_byte channels; /* number of channels in file */
+#ifdef PNG_WRITE_SUPPORTED
+ png_byte usr_channels; /* channels at start of write: write only */
+#endif
+ png_byte sig_bytes; /* magic bytes read/written from start of file */
+ png_byte maximum_pixel_depth;
+ /* pixel depth used for the row buffers */
+ png_byte transformed_pixel_depth;
+ /* pixel depth after read/write transforms */
+#if ZLIB_VERNUM >= 0x1240
+ png_byte zstream_start; /* at start of an input zlib stream */
+#endif /* Zlib >= 1.2.4 */
+#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
+ png_uint_16 filler; /* filler bytes for pixel expansion */
+#endif
+
+#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+ defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+ png_byte background_gamma_type;
+ png_fixed_point background_gamma;
+ png_color_16 background; /* background color in screen gamma space */
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ png_color_16 background_1; /* background normalized to gamma 1.0 */
+#endif
+#endif /* bKGD */
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+ png_flush_ptr output_flush_fn; /* Function for flushing output */
+ png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */
+ png_uint_32 flush_rows; /* number of rows written since last flush */
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ png_xy chromaticities; /* From mDVC, cICP, [iCCP], sRGB or cHRM */
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ int gamma_shift; /* number of "insignificant" bits in 16-bit gamma */
+ png_fixed_point screen_gamma; /* screen gamma value (display exponent) */
+ png_fixed_point file_gamma; /* file gamma value (encoding exponent) */
+ png_fixed_point chunk_gamma; /* from cICP, iCCP, sRGB or gAMA */
+ png_fixed_point default_gamma;/* from png_set_alpha_mode */
+
+ png_bytep gamma_table; /* gamma table for 8-bit depth files */
+ png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+ defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
+ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+ png_bytep gamma_from_1; /* converts from 1.0 to screen */
+ png_bytep gamma_to_1; /* converts from file to 1.0 */
+ png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
+ png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
+#endif /* READ_GAMMA */
+
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
+ png_color_8 sig_bit; /* significant bits in each available channel */
+#endif
+
+#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
+ png_color_8 shift; /* shift for significant bit transformation */
+#endif
+
+#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
+ || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ png_bytep trans_alpha; /* alpha values for paletted files */
+ png_color_16 trans_color; /* transparent color for non-paletted files */
+#endif
+
+ png_read_status_ptr read_row_fn; /* called after each row is decoded */
+ png_write_status_ptr write_row_fn; /* called after each row is encoded */
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+ png_progressive_info_ptr info_fn; /* called after header data fully read */
+ png_progressive_row_ptr row_fn; /* called after a prog. row is decoded */
+ png_progressive_end_ptr end_fn; /* called after image is complete */
+ png_bytep save_buffer_ptr; /* current location in save_buffer */
+ png_bytep save_buffer; /* buffer for previously read data */
+ png_bytep current_buffer_ptr; /* current location in current_buffer */
+ png_bytep current_buffer; /* buffer for recently used data */
+ png_uint_32 push_length; /* size of current input chunk */
+ png_uint_32 skip_length; /* bytes to skip in input data */
+ size_t save_buffer_size; /* amount of data now in save_buffer */
+ size_t save_buffer_max; /* total size of save_buffer */
+ size_t buffer_size; /* total amount of available input data */
+ size_t current_buffer_size; /* amount of data now in current_buffer */
+ int process_mode; /* what push library is currently doing */
+ int cur_palette; /* current push library palette index */
+#endif /* PROGRESSIVE_READ */
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+ png_bytep palette_lookup; /* lookup table for quantizing */
+ png_bytep quantize_index; /* index translation for palette files */
+#endif
+
+/* Options */
+#ifdef PNG_SET_OPTION_SUPPORTED
+ png_uint_32 options; /* On/off state (up to 16 options) */
+#endif
+
+#if PNG_LIBPNG_VER < 10700
+/* To do: remove this from libpng-1.7 */
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+ char time_buffer[29]; /* String to hold RFC 1123 time text */
+#endif /* TIME_RFC1123 */
+#endif /* LIBPNG_VER < 10700 */
+
+/* New members added in libpng-1.0.6 */
+
+ png_uint_32 free_me; /* flags items libpng is responsible for freeing */
+
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+ png_voidp user_chunk_ptr;
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+ png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
+#endif /* READ_USER_CHUNKS */
+#endif /* USER_CHUNKS */
+
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+ int unknown_default; /* As PNG_HANDLE_* */
+ unsigned int num_chunk_list; /* Number of entries in the list */
+ png_bytep chunk_list; /* List of png_byte[5]; the textual chunk name
+ * followed by a PNG_HANDLE_* byte */
+#endif
+
+/* New members added in libpng-1.0.3 */
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ png_byte rgb_to_gray_status;
+ /* Added in libpng 1.5.5 to record setting of coefficients: */
+ png_byte rgb_to_gray_coefficients_set;
+ /* These were changed from png_byte in libpng-1.0.6 */
+ png_uint_16 rgb_to_gray_red_coeff;
+ png_uint_16 rgb_to_gray_green_coeff;
+ /* deleted in 1.5.5: rgb_to_gray_blue_coeff; */
+#endif
+
+/* New member added in libpng-1.6.36 */
+#if defined(PNG_READ_EXPAND_SUPPORTED) && \
+ (defined(PNG_ARM_NEON_IMPLEMENTATION) || \
+ defined(PNG_RISCV_RVV_IMPLEMENTATION))
+ png_bytep riffled_palette; /* buffer for accelerated palette expansion */
+#endif
+
+/* New member added in libpng-1.0.4 (renamed in 1.0.9) */
+#if defined(PNG_MNG_FEATURES_SUPPORTED)
+/* Changed from png_byte to png_uint_32 at version 1.2.0 */
+ png_uint_32 mng_features_permitted;
+#endif
+
+/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ png_byte filter_type;
+#endif
+
+/* New members added in libpng-1.2.0 */
+
+/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
+#ifdef PNG_USER_MEM_SUPPORTED
+ png_voidp mem_ptr; /* user supplied struct for mem functions */
+ png_malloc_ptr malloc_fn; /* function for allocating memory */
+ png_free_ptr free_fn; /* function for freeing memory */
+#endif
+
+/* New member added in libpng-1.0.13 and 1.2.0 */
+ png_bytep big_row_buf; /* buffer to save current (unfiltered) row */
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+/* The following three members were added at version 1.0.14 and 1.2.4 */
+ png_bytep quantize_sort; /* working sort array */
+ png_bytep index_to_palette; /* where the original index currently is
+ in the palette */
+ png_bytep palette_to_index; /* which original index points to this
+ palette color */
+#endif
+
+/* New members added in libpng-1.0.16 and 1.2.6 */
+ png_byte compression_type;
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+ png_uint_32 user_width_max;
+ png_uint_32 user_height_max;
+
+ /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
+ * chunks that can be stored (0 means unlimited).
+ */
+ png_uint_32 user_chunk_cache_max;
+
+ /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk
+ * can occupy when decompressed. 0 means unlimited.
+ */
+ png_alloc_size_t user_chunk_malloc_max;
+#endif
+
+/* New member added in libpng-1.0.25 and 1.2.17 */
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+ /* Temporary storage for unknown chunk that the library doesn't recognize,
+ * used while reading the chunk.
+ */
+ png_unknown_chunk unknown_chunk;
+#endif
+
+/* New member added in libpng-1.2.26 */
+ size_t old_big_row_buf_size;
+
+#ifdef PNG_READ_SUPPORTED
+/* New member added in libpng-1.2.30 */
+ png_bytep read_buffer; /* buffer for reading chunk data */
+ png_alloc_size_t read_buffer_size; /* current size of the buffer */
+#endif
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+ uInt IDAT_read_size; /* limit on read buffer size for IDAT */
+#endif
+
+#ifdef PNG_IO_STATE_SUPPORTED
+/* New member added in libpng-1.4.0 */
+ png_uint_32 io_state;
+#endif
+
+/* New member added in libpng-1.5.6 */
+ png_bytep big_prev_row;
+
+/* New member added in libpng-1.5.7 */
+ void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info,
+ png_bytep row, png_const_bytep prev_row);
+};
+#endif /* PNGSTRUCT_H */
diff --git a/libs/imagequant/external/libpng/pngtrans.c b/libs/imagequant/external/libpng/pngtrans.c
new file mode 100644
index 00000000..222b4987
--- /dev/null
+++ b/libs/imagequant/external/libpng/pngtrans.c
@@ -0,0 +1,867 @@
+/* pngtrans.c - transforms the data in a row (used by both readers and writers)
+ *
+ * Copyright (c) 2018-2024 Cosmin Truta
+ * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "pngpriv.h"
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+/* Turn on BGR-to-RGB mapping */
+void PNGAPI
+png_set_bgr(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_bgr");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->transformations |= PNG_BGR;
+}
+#endif
+
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+/* Turn on 16-bit byte swapping */
+void PNGAPI
+png_set_swap(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_swap");
+
+ if (png_ptr == NULL)
+ return;
+
+ if (png_ptr->bit_depth == 16)
+ png_ptr->transformations |= PNG_SWAP_BYTES;
+}
+#endif
+
+#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+/* Turn on pixel packing */
+void PNGAPI
+png_set_packing(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_packing");
+
+ if (png_ptr == NULL)
+ return;
+
+ if (png_ptr->bit_depth < 8)
+ {
+ png_ptr->transformations |= PNG_PACK;
+# ifdef PNG_WRITE_SUPPORTED
+ png_ptr->usr_bit_depth = 8;
+# endif
+ }
+}
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+/* Turn on packed pixel swapping */
+void PNGAPI
+png_set_packswap(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_packswap");
+
+ if (png_ptr == NULL)
+ return;
+
+ if (png_ptr->bit_depth < 8)
+ png_ptr->transformations |= PNG_PACKSWAP;
+}
+#endif
+
+#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
+void PNGAPI
+png_set_shift(png_structrp png_ptr, png_const_color_8p true_bits)
+{
+ png_debug(1, "in png_set_shift");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->transformations |= PNG_SHIFT;
+ png_ptr->shift = *true_bits;
+}
+#endif
+
+#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
+ defined(PNG_WRITE_INTERLACING_SUPPORTED)
+int PNGAPI
+png_set_interlace_handling(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_interlace handling");
+
+ if (png_ptr != 0 && png_ptr->interlaced != 0)
+ {
+ png_ptr->transformations |= PNG_INTERLACE;
+ return 7;
+ }
+
+ return 1;
+}
+#endif
+
+#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
+/* Add a filler byte on read, or remove a filler or alpha byte on write.
+ * The filler type has changed in v0.95 to allow future 2-byte fillers
+ * for 48-bit input data, as well as to avoid problems with some compilers
+ * that don't like bytes as parameters.
+ */
+void PNGAPI
+png_set_filler(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
+{
+ png_debug(1, "in png_set_filler");
+
+ if (png_ptr == NULL)
+ return;
+
+ /* In libpng 1.6 it is possible to determine whether this is a read or write
+ * operation and therefore to do more checking here for a valid call.
+ */
+ if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
+ {
+# ifdef PNG_READ_FILLER_SUPPORTED
+ /* On read png_set_filler is always valid, regardless of the base PNG
+ * format, because other transformations can give a format where the
+ * filler code can execute (basically an 8 or 16-bit component RGB or G
+ * format.)
+ *
+ * NOTE: usr_channels is not used by the read code! (This has led to
+ * confusion in the past.) The filler is only used in the read code.
+ */
+ png_ptr->filler = (png_uint_16)filler;
+# else
+ png_app_error(png_ptr, "png_set_filler not supported on read");
+ PNG_UNUSED(filler) /* not used in the write case */
+ return;
+# endif
+ }
+
+ else /* write */
+ {
+# ifdef PNG_WRITE_FILLER_SUPPORTED
+ /* On write the usr_channels parameter must be set correctly at the
+ * start to record the number of channels in the app-supplied data.
+ */
+ switch (png_ptr->color_type)
+ {
+ case PNG_COLOR_TYPE_RGB:
+ png_ptr->usr_channels = 4;
+ break;
+
+ case PNG_COLOR_TYPE_GRAY:
+ if (png_ptr->bit_depth >= 8)
+ {
+ png_ptr->usr_channels = 2;
+ break;
+ }
+
+ else
+ {
+ /* There simply isn't any code in libpng to strip out bits
+ * from bytes when the components are less than a byte in
+ * size!
+ */
+ png_app_error(png_ptr,
+ "png_set_filler is invalid for"
+ " low bit depth gray output");
+ return;
+ }
+
+ default:
+ png_app_error(png_ptr,
+ "png_set_filler: inappropriate color type");
+ return;
+ }
+# else
+ png_app_error(png_ptr, "png_set_filler not supported on write");
+ return;
+# endif
+ }
+
+ /* Here on success - libpng supports the operation, set the transformation
+ * and the flag to say where the filler channel is.
+ */
+ png_ptr->transformations |= PNG_FILLER;
+
+ if (filler_loc == PNG_FILLER_AFTER)
+ png_ptr->flags |= PNG_FLAG_FILLER_AFTER;
+
+ else
+ png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER;
+}
+
+/* Added to libpng-1.2.7 */
+void PNGAPI
+png_set_add_alpha(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
+{
+ png_debug(1, "in png_set_add_alpha");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_set_filler(png_ptr, filler, filler_loc);
+ /* The above may fail to do anything. */
+ if ((png_ptr->transformations & PNG_FILLER) != 0)
+ png_ptr->transformations |= PNG_ADD_ALPHA;
+}
+
+#endif
+
+#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
+ defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
+void PNGAPI
+png_set_swap_alpha(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_swap_alpha");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->transformations |= PNG_SWAP_ALPHA;
+}
+#endif
+
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
+ defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
+void PNGAPI
+png_set_invert_alpha(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_invert_alpha");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->transformations |= PNG_INVERT_ALPHA;
+}
+#endif
+
+#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
+void PNGAPI
+png_set_invert_mono(png_structrp png_ptr)
+{
+ png_debug(1, "in png_set_invert_mono");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->transformations |= PNG_INVERT_MONO;
+}
+
+/* Invert monochrome grayscale data */
+void /* PRIVATE */
+png_do_invert(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_invert");
+
+ /* This test removed from libpng version 1.0.13 and 1.2.0:
+ * if (row_info->bit_depth == 1 &&
+ */
+ if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ png_bytep rp = row;
+ size_t i;
+ size_t istop = row_info->rowbytes;
+
+ for (i = 0; i < istop; i++)
+ {
+ *rp = (png_byte)(~(*rp));
+ rp++;
+ }
+ }
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
+ row_info->bit_depth == 8)
+ {
+ png_bytep rp = row;
+ size_t i;
+ size_t istop = row_info->rowbytes;
+
+ for (i = 0; i < istop; i += 2)
+ {
+ *rp = (png_byte)(~(*rp));
+ rp += 2;
+ }
+ }
+
+#ifdef PNG_16BIT_SUPPORTED
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
+ row_info->bit_depth == 16)
+ {
+ png_bytep rp = row;
+ size_t i;
+ size_t istop = row_info->rowbytes;
+
+ for (i = 0; i < istop; i += 4)
+ {
+ *rp = (png_byte)(~(*rp));
+ *(rp + 1) = (png_byte)(~(*(rp + 1)));
+ rp += 4;
+ }
+ }
+#endif
+}
+#endif
+
+#ifdef PNG_16BIT_SUPPORTED
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+/* Swaps byte order on 16-bit depth images */
+void /* PRIVATE */
+png_do_swap(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_swap");
+
+ if (row_info->bit_depth == 16)
+ {
+ png_bytep rp = row;
+ png_uint_32 i;
+ png_uint_32 istop= row_info->width * row_info->channels;
+
+ for (i = 0; i < istop; i++, rp += 2)
+ {
+#ifdef PNG_BUILTIN_BSWAP16_SUPPORTED
+ /* Feature added to libpng-1.6.11 for testing purposes, not
+ * enabled by default.
+ */
+ *(png_uint_16*)rp = __builtin_bswap16(*(png_uint_16*)rp);
+#else
+ png_byte t = *rp;
+ *rp = *(rp + 1);
+ *(rp + 1) = t;
+#endif
+ }
+ }
+}
+#endif
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+static const png_byte onebppswaptable[256] = {
+ 0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0,
+ 0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0,
+ 0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8,
+ 0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8,
+ 0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4,
+ 0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4,
+ 0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC,
+ 0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC,
+ 0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2,
+ 0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2,
+ 0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA,
+ 0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA,
+ 0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6,
+ 0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6,
+ 0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE,
+ 0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE,
+ 0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1,
+ 0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1,
+ 0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9,
+ 0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9,
+ 0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5,
+ 0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5,
+ 0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED,
+ 0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD,
+ 0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3,
+ 0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3,
+ 0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB,
+ 0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB,
+ 0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7,
+ 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7,
+ 0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF,
+ 0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF
+};
+
+static const png_byte twobppswaptable[256] = {
+ 0x00, 0x40, 0x80, 0xC0, 0x10, 0x50, 0x90, 0xD0,
+ 0x20, 0x60, 0xA0, 0xE0, 0x30, 0x70, 0xB0, 0xF0,
+ 0x04, 0x44, 0x84, 0xC4, 0x14, 0x54, 0x94, 0xD4,
+ 0x24, 0x64, 0xA4, 0xE4, 0x34, 0x74, 0xB4, 0xF4,
+ 0x08, 0x48, 0x88, 0xC8, 0x18, 0x58, 0x98, 0xD8,
+ 0x28, 0x68, 0xA8, 0xE8, 0x38, 0x78, 0xB8, 0xF8,
+ 0x0C, 0x4C, 0x8C, 0xCC, 0x1C, 0x5C, 0x9C, 0xDC,
+ 0x2C, 0x6C, 0xAC, 0xEC, 0x3C, 0x7C, 0xBC, 0xFC,
+ 0x01, 0x41, 0x81, 0xC1, 0x11, 0x51, 0x91, 0xD1,
+ 0x21, 0x61, 0xA1, 0xE1, 0x31, 0x71, 0xB1, 0xF1,
+ 0x05, 0x45, 0x85, 0xC5, 0x15, 0x55, 0x95, 0xD5,
+ 0x25, 0x65, 0xA5, 0xE5, 0x35, 0x75, 0xB5, 0xF5,
+ 0x09, 0x49, 0x89, 0xC9, 0x19, 0x59, 0x99, 0xD9,
+ 0x29, 0x69, 0xA9, 0xE9, 0x39, 0x79, 0xB9, 0xF9,
+ 0x0D, 0x4D, 0x8D, 0xCD, 0x1D, 0x5D, 0x9D, 0xDD,
+ 0x2D, 0x6D, 0xAD, 0xED, 0x3D, 0x7D, 0xBD, 0xFD,
+ 0x02, 0x42, 0x82, 0xC2, 0x12, 0x52, 0x92, 0xD2,
+ 0x22, 0x62, 0xA2, 0xE2, 0x32, 0x72, 0xB2, 0xF2,
+ 0x06, 0x46, 0x86, 0xC6, 0x16, 0x56, 0x96, 0xD6,
+ 0x26, 0x66, 0xA6, 0xE6, 0x36, 0x76, 0xB6, 0xF6,
+ 0x0A, 0x4A, 0x8A, 0xCA, 0x1A, 0x5A, 0x9A, 0xDA,
+ 0x2A, 0x6A, 0xAA, 0xEA, 0x3A, 0x7A, 0xBA, 0xFA,
+ 0x0E, 0x4E, 0x8E, 0xCE, 0x1E, 0x5E, 0x9E, 0xDE,
+ 0x2E, 0x6E, 0xAE, 0xEE, 0x3E, 0x7E, 0xBE, 0xFE,
+ 0x03, 0x43, 0x83, 0xC3, 0x13, 0x53, 0x93, 0xD3,
+ 0x23, 0x63, 0xA3, 0xE3, 0x33, 0x73, 0xB3, 0xF3,
+ 0x07, 0x47, 0x87, 0xC7, 0x17, 0x57, 0x97, 0xD7,
+ 0x27, 0x67, 0xA7, 0xE7, 0x37, 0x77, 0xB7, 0xF7,
+ 0x0B, 0x4B, 0x8B, 0xCB, 0x1B, 0x5B, 0x9B, 0xDB,
+ 0x2B, 0x6B, 0xAB, 0xEB, 0x3B, 0x7B, 0xBB, 0xFB,
+ 0x0F, 0x4F, 0x8F, 0xCF, 0x1F, 0x5F, 0x9F, 0xDF,
+ 0x2F, 0x6F, 0xAF, 0xEF, 0x3F, 0x7F, 0xBF, 0xFF
+};
+
+static const png_byte fourbppswaptable[256] = {
+ 0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70,
+ 0x80, 0x90, 0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0,
+ 0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x61, 0x71,
+ 0x81, 0x91, 0xA1, 0xB1, 0xC1, 0xD1, 0xE1, 0xF1,
+ 0x02, 0x12, 0x22, 0x32, 0x42, 0x52, 0x62, 0x72,
+ 0x82, 0x92, 0xA2, 0xB2, 0xC2, 0xD2, 0xE2, 0xF2,
+ 0x03, 0x13, 0x23, 0x33, 0x43, 0x53, 0x63, 0x73,
+ 0x83, 0x93, 0xA3, 0xB3, 0xC3, 0xD3, 0xE3, 0xF3,
+ 0x04, 0x14, 0x24, 0x34, 0x44, 0x54, 0x64, 0x74,
+ 0x84, 0x94, 0xA4, 0xB4, 0xC4, 0xD4, 0xE4, 0xF4,
+ 0x05, 0x15, 0x25, 0x35, 0x45, 0x55, 0x65, 0x75,
+ 0x85, 0x95, 0xA5, 0xB5, 0xC5, 0xD5, 0xE5, 0xF5,
+ 0x06, 0x16, 0x26, 0x36, 0x46, 0x56, 0x66, 0x76,
+ 0x86, 0x96, 0xA6, 0xB6, 0xC6, 0xD6, 0xE6, 0xF6,
+ 0x07, 0x17, 0x27, 0x37, 0x47, 0x57, 0x67, 0x77,
+ 0x87, 0x97, 0xA7, 0xB7, 0xC7, 0xD7, 0xE7, 0xF7,
+ 0x08, 0x18, 0x28, 0x38, 0x48, 0x58, 0x68, 0x78,
+ 0x88, 0x98, 0xA8, 0xB8, 0xC8, 0xD8, 0xE8, 0xF8,
+ 0x09, 0x19, 0x29, 0x39, 0x49, 0x59, 0x69, 0x79,
+ 0x89, 0x99, 0xA9, 0xB9, 0xC9, 0xD9, 0xE9, 0xF9,
+ 0x0A, 0x1A, 0x2A, 0x3A, 0x4A, 0x5A, 0x6A, 0x7A,
+ 0x8A, 0x9A, 0xAA, 0xBA, 0xCA, 0xDA, 0xEA, 0xFA,
+ 0x0B, 0x1B, 0x2B, 0x3B, 0x4B, 0x5B, 0x6B, 0x7B,
+ 0x8B, 0x9B, 0xAB, 0xBB, 0xCB, 0xDB, 0xEB, 0xFB,
+ 0x0C, 0x1C, 0x2C, 0x3C, 0x4C, 0x5C, 0x6C, 0x7C,
+ 0x8C, 0x9C, 0xAC, 0xBC, 0xCC, 0xDC, 0xEC, 0xFC,
+ 0x0D, 0x1D, 0x2D, 0x3D, 0x4D, 0x5D, 0x6D, 0x7D,
+ 0x8D, 0x9D, 0xAD, 0xBD, 0xCD, 0xDD, 0xED, 0xFD,
+ 0x0E, 0x1E, 0x2E, 0x3E, 0x4E, 0x5E, 0x6E, 0x7E,
+ 0x8E, 0x9E, 0xAE, 0xBE, 0xCE, 0xDE, 0xEE, 0xFE,
+ 0x0F, 0x1F, 0x2F, 0x3F, 0x4F, 0x5F, 0x6F, 0x7F,
+ 0x8F, 0x9F, 0xAF, 0xBF, 0xCF, 0xDF, 0xEF, 0xFF
+};
+
+/* Swaps pixel packing order within bytes */
+void /* PRIVATE */
+png_do_packswap(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_packswap");
+
+ if (row_info->bit_depth < 8)
+ {
+ png_bytep rp;
+ png_const_bytep end, table;
+
+ end = row + row_info->rowbytes;
+
+ if (row_info->bit_depth == 1)
+ table = onebppswaptable;
+
+ else if (row_info->bit_depth == 2)
+ table = twobppswaptable;
+
+ else if (row_info->bit_depth == 4)
+ table = fourbppswaptable;
+
+ else
+ return;
+
+ for (rp = row; rp < end; rp++)
+ *rp = table[*rp];
+ }
+}
+#endif /* PACKSWAP || WRITE_PACKSWAP */
+
+#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
+ defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+/* Remove a channel - this used to be 'png_do_strip_filler' but it used a
+ * somewhat weird combination of flags to determine what to do. All the calls
+ * to png_do_strip_filler are changed in 1.5.2 to call this instead with the
+ * correct arguments.
+ *
+ * The routine isn't general - the channel must be the channel at the start or
+ * end (not in the middle) of each pixel.
+ */
+void /* PRIVATE */
+png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)
+{
+ png_bytep sp = row; /* source pointer */
+ png_bytep dp = row; /* destination pointer */
+ png_bytep ep = row + row_info->rowbytes; /* One beyond end of row */
+
+ png_debug(1, "in png_do_strip_channel");
+
+ /* At the start sp will point to the first byte to copy and dp to where
+ * it is copied to. ep always points just beyond the end of the row, so
+ * the loop simply copies (channels-1) channels until sp reaches ep.
+ *
+ * at_start: 0 -- convert AG, XG, ARGB, XRGB, AAGG, XXGG, etc.
+ * nonzero -- convert GA, GX, RGBA, RGBX, GGAA, RRGGBBXX, etc.
+ */
+
+ /* GA, GX, XG cases */
+ if (row_info->channels == 2)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ if (at_start != 0) /* Skip initial filler */
+ ++sp;
+ else /* Skip initial channel and, for sp, the filler */
+ {
+ sp += 2; ++dp;
+ }
+
+ /* For a 1 pixel wide image there is nothing to do */
+ while (sp < ep)
+ {
+ *dp++ = *sp; sp += 2;
+ }
+
+ row_info->pixel_depth = 8;
+ }
+
+ else if (row_info->bit_depth == 16)
+ {
+ if (at_start != 0) /* Skip initial filler */
+ sp += 2;
+ else /* Skip initial channel and, for sp, the filler */
+ {
+ sp += 4; dp += 2;
+ }
+
+ while (sp < ep)
+ {
+ *dp++ = *sp++; *dp++ = *sp; sp += 3;
+ }
+
+ row_info->pixel_depth = 16;
+ }
+
+ else
+ return; /* bad bit depth */
+
+ row_info->channels = 1;
+
+ /* Finally fix the color type if it records an alpha channel */
+ if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ row_info->color_type = PNG_COLOR_TYPE_GRAY;
+ }
+
+ /* RGBA, RGBX, XRGB cases */
+ else if (row_info->channels == 4)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ if (at_start != 0) /* Skip initial filler */
+ ++sp;
+ else /* Skip initial channels and, for sp, the filler */
+ {
+ sp += 4; dp += 3;
+ }
+
+ /* Note that the loop adds 3 to dp and 4 to sp each time. */
+ while (sp < ep)
+ {
+ *dp++ = *sp++; *dp++ = *sp++; *dp++ = *sp; sp += 2;
+ }
+
+ row_info->pixel_depth = 24;
+ }
+
+ else if (row_info->bit_depth == 16)
+ {
+ if (at_start != 0) /* Skip initial filler */
+ sp += 2;
+ else /* Skip initial channels and, for sp, the filler */
+ {
+ sp += 8; dp += 6;
+ }
+
+ while (sp < ep)
+ {
+ /* Copy 6 bytes, skip 2 */
+ *dp++ = *sp++; *dp++ = *sp++;
+ *dp++ = *sp++; *dp++ = *sp++;
+ *dp++ = *sp++; *dp++ = *sp; sp += 3;
+ }
+
+ row_info->pixel_depth = 48;
+ }
+
+ else
+ return; /* bad bit depth */
+
+ row_info->channels = 3;
+
+ /* Finally fix the color type if it records an alpha channel */
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ row_info->color_type = PNG_COLOR_TYPE_RGB;
+ }
+
+ else
+ return; /* The filler channel has gone already */
+
+ /* Fix the rowbytes value. */
+ row_info->rowbytes = (size_t)(dp-row);
+}
+#endif
+
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+/* Swaps red and blue bytes within a pixel */
+void /* PRIVATE */
+png_do_bgr(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_bgr");
+
+ if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ {
+ png_uint_32 row_width = row_info->width;
+ if (row_info->bit_depth == 8)
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += 3)
+ {
+ png_byte save = *rp;
+ *rp = *(rp + 2);
+ *(rp + 2) = save;
+ }
+ }
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += 4)
+ {
+ png_byte save = *rp;
+ *rp = *(rp + 2);
+ *(rp + 2) = save;
+ }
+ }
+ }
+
+#ifdef PNG_16BIT_SUPPORTED
+ else if (row_info->bit_depth == 16)
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += 6)
+ {
+ png_byte save = *rp;
+ *rp = *(rp + 4);
+ *(rp + 4) = save;
+ save = *(rp + 1);
+ *(rp + 1) = *(rp + 5);
+ *(rp + 5) = save;
+ }
+ }
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += 8)
+ {
+ png_byte save = *rp;
+ *rp = *(rp + 4);
+ *(rp + 4) = save;
+ save = *(rp + 1);
+ *(rp + 1) = *(rp + 5);
+ *(rp + 5) = save;
+ }
+ }
+ }
+#endif
+ }
+}
+#endif /* READ_BGR || WRITE_BGR */
+
+#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
+ defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
+/* Added at libpng-1.5.10 */
+void /* PRIVATE */
+png_do_check_palette_indexes(png_structrp png_ptr, png_row_infop row_info)
+{
+ png_debug(1, "in png_do_check_palette_indexes");
+
+ if (png_ptr->num_palette < (1 << row_info->bit_depth) &&
+ png_ptr->num_palette > 0) /* num_palette can be 0 in MNG files */
+ {
+ /* Calculations moved outside switch in an attempt to stop different
+ * compiler warnings. 'padding' is in *bits* within the last byte, it is
+ * an 'int' because pixel_depth becomes an 'int' in the expression below,
+ * and this calculation is used because it avoids warnings that other
+ * forms produced on either GCC or MSVC.
+ */
+ int padding = PNG_PADBITS(row_info->pixel_depth, row_info->width);
+ png_bytep rp = png_ptr->row_buf + row_info->rowbytes;
+
+ switch (row_info->bit_depth)
+ {
+ case 1:
+ {
+ /* in this case, all bytes must be 0 so we don't need
+ * to unpack the pixels except for the rightmost one.
+ */
+ for (; rp > png_ptr->row_buf; rp--)
+ {
+ if ((*rp >> padding) != 0)
+ png_ptr->num_palette_max = 1;
+ padding = 0;
+ }
+
+ break;
+ }
+
+ case 2:
+ {
+ for (; rp > png_ptr->row_buf; rp--)
+ {
+ int i = ((*rp >> padding) & 0x03);
+
+ if (i > png_ptr->num_palette_max)
+ png_ptr->num_palette_max = i;
+
+ i = (((*rp >> padding) >> 2) & 0x03);
+
+ if (i > png_ptr->num_palette_max)
+ png_ptr->num_palette_max = i;
+
+ i = (((*rp >> padding) >> 4) & 0x03);
+
+ if (i > png_ptr->num_palette_max)
+ png_ptr->num_palette_max = i;
+
+ i = (((*rp >> padding) >> 6) & 0x03);
+
+ if (i > png_ptr->num_palette_max)
+ png_ptr->num_palette_max = i;
+
+ padding = 0;
+ }
+
+ break;
+ }
+
+ case 4:
+ {
+ for (; rp > png_ptr->row_buf; rp--)
+ {
+ int i = ((*rp >> padding) & 0x0f);
+
+ if (i > png_ptr->num_palette_max)
+ png_ptr->num_palette_max = i;
+
+ i = (((*rp >> padding) >> 4) & 0x0f);
+
+ if (i > png_ptr->num_palette_max)
+ png_ptr->num_palette_max = i;
+
+ padding = 0;
+ }
+
+ break;
+ }
+
+ case 8:
+ {
+ for (; rp > png_ptr->row_buf; rp--)
+ {
+ if (*rp > png_ptr->num_palette_max)
+ png_ptr->num_palette_max = (int) *rp;
+ }
+
+ break;
+ }
+
+ default:
+ break;
+ }
+ }
+}
+#endif /* CHECK_FOR_INVALID_INDEX */
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+void PNGAPI
+png_set_user_transform_info(png_structrp png_ptr, png_voidp
+ user_transform_ptr, int user_transform_depth, int user_transform_channels)
+{
+ png_debug(1, "in png_set_user_transform_info");
+
+ if (png_ptr == NULL)
+ return;
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+ if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
+ (png_ptr->flags & PNG_FLAG_ROW_INIT) != 0)
+ {
+ png_app_error(png_ptr,
+ "info change after png_start_read_image or png_read_update_info");
+ return;
+ }
+#endif
+
+ png_ptr->user_transform_ptr = user_transform_ptr;
+ png_ptr->user_transform_depth = (png_byte)user_transform_depth;
+ png_ptr->user_transform_channels = (png_byte)user_transform_channels;
+}
+#endif
+
+/* This function returns a pointer to the user_transform_ptr associated with
+ * the user transform functions. The application should free any memory
+ * associated with this pointer before png_write_destroy and png_read_destroy
+ * are called.
+ */
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+png_voidp PNGAPI
+png_get_user_transform_ptr(png_const_structrp png_ptr)
+{
+ if (png_ptr == NULL)
+ return NULL;
+
+ return png_ptr->user_transform_ptr;
+}
+#endif
+
+#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
+png_uint_32 PNGAPI
+png_get_current_row_number(png_const_structrp png_ptr)
+{
+ /* See the comments in png.h - this is the sub-image row when reading an
+ * interlaced image.
+ */
+ if (png_ptr != NULL)
+ return png_ptr->row_number;
+
+ return PNG_UINT_32_MAX; /* help the app not to fail silently */
+}
+
+png_byte PNGAPI
+png_get_current_pass_number(png_const_structrp png_ptr)
+{
+ if (png_ptr != NULL)
+ return png_ptr->pass;
+ return 8; /* invalid */
+}
+#endif /* USER_TRANSFORM_INFO */
+#endif /* READ_USER_TRANSFORM || WRITE_USER_TRANSFORM */
+#endif /* READ || WRITE */
diff --git a/libs/imagequant/external/libpng/pngusr.dfa b/libs/imagequant/external/libpng/pngusr.dfa
new file mode 100644
index 00000000..83067c38
--- /dev/null
+++ b/libs/imagequant/external/libpng/pngusr.dfa
@@ -0,0 +1,14 @@
+# pngusr.dfa
+#
+# Build time configuration of libpng
+#
+# Enter build configuration options in this file
+#
+# Security settings: by default these limits are unset, you can change them
+# here by entering the appropriate values as #defines preceded by '@' (to cause,
+# them to be passed through to the build of pnglibconf.h), for example:
+#
+# @# define PNG_USER_WIDTH_MAX 65535
+# @# define PNG_USER_HEIGHT_MAX 65535
+# @# define PNG_USER_CHUNK_CACHE_MAX 256
+# @# define PNG_USER_CHUNK_MALLOC_MAX 640000
diff --git a/libs/imagequant/external/libpng/pngwio.c b/libs/imagequant/external/libpng/pngwio.c
new file mode 100644
index 00000000..96a3187f
--- /dev/null
+++ b/libs/imagequant/external/libpng/pngwio.c
@@ -0,0 +1,167 @@
+/* pngwio.c - functions for data output
+ *
+ * Copyright (c) 2018-2025 Cosmin Truta
+ * Copyright (c) 1998-2002,2004,2006-2014,2016,2018 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all output. Users who need
+ * special handling are expected to write functions that have the same
+ * arguments as these and perform similar functions, but that possibly
+ * use different output methods. Note that you shouldn't change these
+ * functions, but rather write replacement functions and then change
+ * them at run time with png_set_write_fn(...).
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_WRITE_SUPPORTED
+
+/* Write the data to whatever output you are using. The default routine
+ * writes to a file pointer. Note that this routine sometimes gets called
+ * with very small lengths, so you should implement some kind of simple
+ * buffering if you are using unbuffered writes. This should never be asked
+ * to write more than 64K on a 16-bit machine.
+ */
+
+void /* PRIVATE */
+png_write_data(png_structrp png_ptr, png_const_bytep data, size_t length)
+{
+ /* NOTE: write_data_fn must not change the buffer! */
+ if (png_ptr->write_data_fn != NULL )
+ (*(png_ptr->write_data_fn))(png_ptr, png_constcast(png_bytep,data),
+ length);
+
+ else
+ png_error(png_ptr, "Call to NULL write function");
+}
+
+#ifdef PNG_STDIO_SUPPORTED
+/* This is the function that does the actual writing of data. If you are
+ * not writing to a standard C stream, you should create a replacement
+ * write_data function and use it at run time with png_set_write_fn(), rather
+ * than changing the library.
+ */
+void PNGCBAPI
+png_default_write_data(png_structp png_ptr, png_bytep data, size_t length)
+{
+ size_t check;
+
+ if (png_ptr == NULL)
+ return;
+
+ check = fwrite(data, 1, length, (FILE *)png_ptr->io_ptr);
+
+ if (check != length)
+ png_error(png_ptr, "Write Error");
+}
+#endif
+
+/* This function is called to output any data pending writing (normally
+ * to disk). After png_flush is called, there should be no data pending
+ * writing in any buffers.
+ */
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+void /* PRIVATE */
+png_flush(png_structrp png_ptr)
+{
+ if (png_ptr->output_flush_fn != NULL)
+ (*(png_ptr->output_flush_fn))(png_ptr);
+}
+
+# ifdef PNG_STDIO_SUPPORTED
+void PNGCBAPI
+png_default_flush(png_structp png_ptr)
+{
+ FILE *io_ptr;
+
+ if (png_ptr == NULL)
+ return;
+
+ io_ptr = png_voidcast(FILE *, png_ptr->io_ptr);
+ fflush(io_ptr);
+}
+# endif
+#endif
+
+/* This function allows the application to supply new output functions for
+ * libpng if standard C streams aren't being used.
+ *
+ * This function takes as its arguments:
+ * png_ptr - pointer to a png output data structure
+ * io_ptr - pointer to user supplied structure containing info about
+ * the output functions. May be NULL.
+ * write_data_fn - pointer to a new output function that takes as its
+ * arguments a pointer to a png_struct, a pointer to
+ * data to be written, and a 32-bit unsigned int that is
+ * the number of bytes to be written. The new write
+ * function should call png_error(png_ptr, "Error msg")
+ * to exit and output any fatal error messages. May be
+ * NULL, in which case libpng's default function will
+ * be used.
+ * flush_data_fn - pointer to a new flush function that takes as its
+ * arguments a pointer to a png_struct. After a call to
+ * the flush function, there should be no data in any buffers
+ * or pending transmission. If the output method doesn't do
+ * any buffering of output, a function prototype must still be
+ * supplied although it doesn't have to do anything. If
+ * PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile
+ * time, output_flush_fn will be ignored, although it must be
+ * supplied for compatibility. May be NULL, in which case
+ * libpng's default function will be used, if
+ * PNG_WRITE_FLUSH_SUPPORTED is defined. This is not
+ * a good idea if io_ptr does not point to a standard
+ * *FILE structure.
+ */
+void PNGAPI
+png_set_write_fn(png_structrp png_ptr, png_voidp io_ptr,
+ png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)
+{
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->io_ptr = io_ptr;
+
+#ifdef PNG_STDIO_SUPPORTED
+ if (write_data_fn != NULL)
+ png_ptr->write_data_fn = write_data_fn;
+
+ else
+ png_ptr->write_data_fn = png_default_write_data;
+#else
+ png_ptr->write_data_fn = write_data_fn;
+#endif
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+# ifdef PNG_STDIO_SUPPORTED
+
+ if (output_flush_fn != NULL)
+ png_ptr->output_flush_fn = output_flush_fn;
+
+ else
+ png_ptr->output_flush_fn = png_default_flush;
+
+# else
+ png_ptr->output_flush_fn = output_flush_fn;
+# endif
+#else
+ PNG_UNUSED(output_flush_fn)
+#endif /* WRITE_FLUSH */
+
+#ifdef PNG_READ_SUPPORTED
+ /* It is an error to read while writing a png file */
+ if (png_ptr->read_data_fn != NULL)
+ {
+ png_ptr->read_data_fn = NULL;
+
+ png_warning(png_ptr,
+ "Can't set both read_data_fn and write_data_fn in the"
+ " same structure");
+ }
+#endif
+}
+#endif /* WRITE */
diff --git a/libs/imagequant/external/libpng/pngwrite.c b/libs/imagequant/external/libpng/pngwrite.c
new file mode 100644
index 00000000..35a5d17b
--- /dev/null
+++ b/libs/imagequant/external/libpng/pngwrite.c
@@ -0,0 +1,2449 @@
+/* pngwrite.c - general routines to write a PNG file
+ *
+ * Copyright (c) 2018-2025 Cosmin Truta
+ * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "pngpriv.h"
+#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
+# include
+#endif /* SIMPLIFIED_WRITE_STDIO */
+
+#ifdef PNG_WRITE_SUPPORTED
+
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+/* Write out all the unknown chunks for the current given location */
+static void
+write_unknown_chunks(png_structrp png_ptr, png_const_inforp info_ptr,
+ unsigned int where)
+{
+ if (info_ptr->unknown_chunks_num != 0)
+ {
+ png_const_unknown_chunkp up;
+
+ png_debug(5, "writing extra chunks");
+
+ for (up = info_ptr->unknown_chunks;
+ up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
+ ++up)
+ if ((up->location & where) != 0)
+ {
+ /* If per-chunk unknown chunk handling is enabled use it, otherwise
+ * just write the chunks the application has set.
+ */
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+ int keep = png_handle_as_unknown(png_ptr, up->name);
+
+ /* NOTE: this code is radically different from the read side in the
+ * matter of handling an ancillary unknown chunk. In the read side
+ * the default behavior is to discard it, in the code below the default
+ * behavior is to write it. Critical chunks are, however, only
+ * written if explicitly listed or if the default is set to write all
+ * unknown chunks.
+ *
+ * The default handling is also slightly weird - it is not possible to
+ * stop the writing of all unsafe-to-copy chunks!
+ *
+ * TODO: REVIEW: this would seem to be a bug.
+ */
+ if (keep != PNG_HANDLE_CHUNK_NEVER &&
+ ((up->name[3] & 0x20) /* safe-to-copy overrides everything */ ||
+ keep == PNG_HANDLE_CHUNK_ALWAYS ||
+ (keep == PNG_HANDLE_CHUNK_AS_DEFAULT &&
+ png_ptr->unknown_default == PNG_HANDLE_CHUNK_ALWAYS)))
+#endif
+ {
+ /* TODO: review, what is wrong with a zero length unknown chunk? */
+ if (up->size == 0)
+ png_warning(png_ptr, "Writing zero-length unknown chunk");
+
+ png_write_chunk(png_ptr, up->name, up->data, up->size);
+ }
+ }
+ }
+}
+#endif /* WRITE_UNKNOWN_CHUNKS */
+
+/* Writes all the PNG information. This is the suggested way to use the
+ * library. If you have a new chunk to add, make a function to write it,
+ * and put it in the correct location here. If you want the chunk written
+ * after the image data, put it in png_write_end(). I strongly encourage
+ * you to supply a PNG_INFO_ flag, and check info_ptr->valid before
+ * writing the chunk, as that will keep the code from breaking if you want
+ * to just write a plain PNG file. If you have long comments, I suggest
+ * writing them in png_write_end(), and compressing them.
+ */
+void PNGAPI
+png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr)
+{
+ png_debug(1, "in png_write_info_before_PLTE");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ if ((png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE) == 0)
+ {
+ /* Write PNG signature */
+ png_write_sig(png_ptr);
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0 && \
+ png_ptr->mng_features_permitted != 0)
+ {
+ png_warning(png_ptr,
+ "MNG features are not allowed in a PNG datastream");
+ png_ptr->mng_features_permitted = 0;
+ }
+#endif
+
+ /* Write IHDR information. */
+ png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
+ info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
+ info_ptr->filter_type,
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ info_ptr->interlace_type
+#else
+ 0
+#endif
+ );
+
+ /* The rest of these check to see if the valid field has the appropriate
+ * flag set, and if it does, writes the chunk.
+ *
+ * 1.6.0: COLORSPACE support controls the writing of these chunks too, and
+ * the chunks will be written if the WRITE routine is there and
+ * information * is available in the COLORSPACE. (See
+ * png_colorspace_sync_info in png.c for where the valid flags get set.)
+ *
+ * Under certain circumstances the colorspace can be invalidated without
+ * syncing the info_struct 'valid' flags; this happens if libpng detects
+ * an error and calls png_error while the color space is being set, yet
+ * the application continues writing the PNG. So check the 'invalid'
+ * flag here too.
+ */
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+ /* Write unknown chunks first; PNG v3 establishes a precedence order
+ * for colourspace chunks. It is certain therefore that new
+ * colourspace chunks will have a precedence and very likely it will be
+ * higher than all known so far. Writing the unknown chunks here is
+ * most likely to present the chunks in the most convenient order.
+ *
+ * FUTURE: maybe write chunks in the order the app calls png_set_chnk
+ * to give the app control.
+ */
+ write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_IHDR);
+#endif
+
+#ifdef PNG_WRITE_sBIT_SUPPORTED
+ /* PNG v3: a streaming app will need to see this before cICP because
+ * the information is helpful in handling HLG encoding (which is
+ * natively 10 bits but gets expanded to 16 in PNG.)
+ *
+ * The app shouldn't care about the order ideally, but it might have
+ * no choice. In PNG v3, apps are allowed to reject PNGs where the
+ * APNG chunks are out of order so it behooves libpng to be nice here.
+ */
+ if ((info_ptr->valid & PNG_INFO_sBIT) != 0)
+ png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
+#endif
+
+ /* PNG v3: the July 2004 version of the TR introduced the concept of colour
+ * space priority. As above it therefore behooves libpng to write the colour
+ * space chunks in the priority order so that a streaming app need not buffer
+ * them.
+ *
+ * PNG v3: Chunks mDCV and cLLI provide ancillary information for the
+ * interpretation of the colourspace chunkgs but do not require support for
+ * those chunks so are outside the "COLORSPACE" check but before the write of
+ * the colourspace chunks themselves.
+ */
+#ifdef PNG_WRITE_cLLI_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_cLLI) != 0)
+ {
+ png_write_cLLI_fixed(png_ptr, info_ptr->maxCLL, info_ptr->maxFALL);
+ }
+#endif
+#ifdef PNG_WRITE_mDCV_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_mDCV) != 0)
+ {
+ png_write_mDCV_fixed(png_ptr,
+ info_ptr->mastering_red_x, info_ptr->mastering_red_y,
+ info_ptr->mastering_green_x, info_ptr->mastering_green_y,
+ info_ptr->mastering_blue_x, info_ptr->mastering_blue_y,
+ info_ptr->mastering_white_x, info_ptr->mastering_white_y,
+ info_ptr->mastering_maxDL, info_ptr->mastering_minDL);
+ }
+#endif
+
+# ifdef PNG_WRITE_cICP_SUPPORTED /* Priority 4 */
+ if ((info_ptr->valid & PNG_INFO_cICP) != 0)
+ {
+ png_write_cICP(png_ptr,
+ info_ptr->cicp_colour_primaries,
+ info_ptr->cicp_transfer_function,
+ info_ptr->cicp_matrix_coefficients,
+ info_ptr->cicp_video_full_range_flag);
+ }
+# endif
+
+# ifdef PNG_WRITE_iCCP_SUPPORTED /* Priority 3 */
+ if ((info_ptr->valid & PNG_INFO_iCCP) != 0)
+ {
+ png_write_iCCP(png_ptr, info_ptr->iccp_name,
+ info_ptr->iccp_profile, info_ptr->iccp_proflen);
+ }
+# endif
+
+# ifdef PNG_WRITE_sRGB_SUPPORTED /* Priority 2 */
+ if ((info_ptr->valid & PNG_INFO_sRGB) != 0)
+ png_write_sRGB(png_ptr, info_ptr->rendering_intent);
+# endif /* WRITE_sRGB */
+
+# ifdef PNG_WRITE_gAMA_SUPPORTED /* Priority 1 */
+ if ((info_ptr->valid & PNG_INFO_gAMA) != 0)
+ png_write_gAMA_fixed(png_ptr, info_ptr->gamma);
+# endif
+
+# ifdef PNG_WRITE_cHRM_SUPPORTED /* Also priority 1 */
+ if ((info_ptr->valid & PNG_INFO_cHRM) != 0)
+ png_write_cHRM_fixed(png_ptr, &info_ptr->cHRM);
+# endif
+
+ png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
+ }
+}
+
+void PNGAPI
+png_write_info(png_structrp png_ptr, png_const_inforp info_ptr)
+{
+#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
+ int i;
+#endif
+
+ png_debug(1, "in png_write_info");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ png_write_info_before_PLTE(png_ptr, info_ptr);
+
+ if ((info_ptr->valid & PNG_INFO_PLTE) != 0)
+ png_write_PLTE(png_ptr, info_ptr->palette,
+ (png_uint_32)info_ptr->num_palette);
+
+ else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ png_error(png_ptr, "Valid palette required for paletted images");
+
+#ifdef PNG_WRITE_tRNS_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_tRNS) !=0)
+ {
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+ /* Invert the alpha channel (in tRNS) */
+ if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0 &&
+ info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ int j, jend;
+
+ jend = info_ptr->num_trans;
+ if (jend > PNG_MAX_PALETTE_LENGTH)
+ jend = PNG_MAX_PALETTE_LENGTH;
+
+ for (j = 0; jtrans_alpha[j] =
+ (png_byte)(255 - info_ptr->trans_alpha[j]);
+ }
+#endif
+ png_write_tRNS(png_ptr, info_ptr->trans_alpha, &(info_ptr->trans_color),
+ info_ptr->num_trans, info_ptr->color_type);
+ }
+#endif
+#ifdef PNG_WRITE_bKGD_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_bKGD) != 0)
+ png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
+#endif
+
+#ifdef PNG_WRITE_eXIf_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_eXIf) != 0)
+ {
+ png_write_eXIf(png_ptr, info_ptr->exif, info_ptr->num_exif);
+ png_ptr->mode |= PNG_WROTE_eXIf;
+ }
+#endif
+
+#ifdef PNG_WRITE_hIST_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_hIST) != 0)
+ png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
+#endif
+
+#ifdef PNG_WRITE_oFFs_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_oFFs) != 0)
+ png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
+ info_ptr->offset_unit_type);
+#endif
+
+#ifdef PNG_WRITE_pCAL_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_pCAL) != 0)
+ png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
+ info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
+ info_ptr->pcal_units, info_ptr->pcal_params);
+#endif
+
+#ifdef PNG_WRITE_sCAL_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_sCAL) != 0)
+ png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
+ info_ptr->scal_s_width, info_ptr->scal_s_height);
+#endif /* sCAL */
+
+#ifdef PNG_WRITE_pHYs_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_pHYs) != 0)
+ png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
+ info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
+#endif /* pHYs */
+
+#ifdef PNG_WRITE_tIME_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_tIME) != 0)
+ {
+ png_write_tIME(png_ptr, &(info_ptr->mod_time));
+ png_ptr->mode |= PNG_WROTE_tIME;
+ }
+#endif /* tIME */
+
+#ifdef PNG_WRITE_sPLT_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_sPLT) != 0)
+ for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
+ png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
+#endif /* sPLT */
+
+#ifdef PNG_WRITE_TEXT_SUPPORTED
+ /* Check to see if we need to write text chunks */
+ for (i = 0; i < info_ptr->num_text; i++)
+ {
+ png_debug2(2, "Writing header text chunk %d, type %d", i,
+ info_ptr->text[i].compression);
+ /* An internationalized chunk? */
+ if (info_ptr->text[i].compression > 0)
+ {
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+ /* Write international chunk */
+ png_write_iTXt(png_ptr,
+ info_ptr->text[i].compression,
+ info_ptr->text[i].key,
+ info_ptr->text[i].lang,
+ info_ptr->text[i].lang_key,
+ info_ptr->text[i].text);
+ /* Mark this chunk as written */
+ if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+ else
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
+#else
+ png_warning(png_ptr, "Unable to write international text");
+#endif
+ }
+
+ /* If we want a compressed text chunk */
+ else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
+ {
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+ /* Write compressed chunk */
+ png_write_zTXt(png_ptr, info_ptr->text[i].key,
+ info_ptr->text[i].text, info_ptr->text[i].compression);
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
+#else
+ png_warning(png_ptr, "Unable to write compressed text");
+#endif
+ }
+
+ else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+ {
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+ /* Write uncompressed chunk */
+ png_write_tEXt(png_ptr, info_ptr->text[i].key,
+ info_ptr->text[i].text,
+ 0);
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+#else
+ /* Can't get here */
+ png_warning(png_ptr, "Unable to write uncompressed text");
+#endif
+ }
+ }
+#endif /* tEXt */
+
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+ write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_PLTE);
+#endif
+}
+
+/* Writes the end of the PNG file. If you don't want to write comments or
+ * time information, you can pass NULL for info. If you already wrote these
+ * in png_write_info(), do not write them again here. If you have long
+ * comments, I suggest writing them here, and compressing them.
+ */
+void PNGAPI
+png_write_end(png_structrp png_ptr, png_inforp info_ptr)
+{
+ png_debug(1, "in png_write_end");
+
+ if (png_ptr == NULL)
+ return;
+
+ if ((png_ptr->mode & PNG_HAVE_IDAT) == 0)
+ png_error(png_ptr, "No IDATs written into file");
+
+#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+ png_ptr->num_palette_max >= png_ptr->num_palette)
+ png_benign_error(png_ptr, "Wrote palette index exceeding num_palette");
+#endif
+
+ /* See if user wants us to write information chunks */
+ if (info_ptr != NULL)
+ {
+#ifdef PNG_WRITE_TEXT_SUPPORTED
+ int i; /* local index variable */
+#endif
+#ifdef PNG_WRITE_tIME_SUPPORTED
+ /* Check to see if user has supplied a time chunk */
+ if ((info_ptr->valid & PNG_INFO_tIME) != 0 &&
+ (png_ptr->mode & PNG_WROTE_tIME) == 0)
+ png_write_tIME(png_ptr, &(info_ptr->mod_time));
+
+#endif
+#ifdef PNG_WRITE_TEXT_SUPPORTED
+ /* Loop through comment chunks */
+ for (i = 0; i < info_ptr->num_text; i++)
+ {
+ png_debug2(2, "Writing trailer text chunk %d, type %d", i,
+ info_ptr->text[i].compression);
+ /* An internationalized chunk? */
+ if (info_ptr->text[i].compression > 0)
+ {
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+ /* Write international chunk */
+ png_write_iTXt(png_ptr,
+ info_ptr->text[i].compression,
+ info_ptr->text[i].key,
+ info_ptr->text[i].lang,
+ info_ptr->text[i].lang_key,
+ info_ptr->text[i].text);
+ /* Mark this chunk as written */
+ if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+ else
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
+#else
+ png_warning(png_ptr, "Unable to write international text");
+#endif
+ }
+
+ else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
+ {
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+ /* Write compressed chunk */
+ png_write_zTXt(png_ptr, info_ptr->text[i].key,
+ info_ptr->text[i].text, info_ptr->text[i].compression);
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
+#else
+ png_warning(png_ptr, "Unable to write compressed text");
+#endif
+ }
+
+ else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+ {
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+ /* Write uncompressed chunk */
+ png_write_tEXt(png_ptr, info_ptr->text[i].key,
+ info_ptr->text[i].text, 0);
+ /* Mark this chunk as written */
+ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+#else
+ png_warning(png_ptr, "Unable to write uncompressed text");
+#endif
+ }
+ }
+#endif
+
+#ifdef PNG_WRITE_eXIf_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_eXIf) != 0 &&
+ (png_ptr->mode & PNG_WROTE_eXIf) == 0)
+ png_write_eXIf(png_ptr, info_ptr->exif, info_ptr->num_exif);
+#endif
+
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+ write_unknown_chunks(png_ptr, info_ptr, PNG_AFTER_IDAT);
+#endif
+ }
+
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+ /* Write end of PNG file */
+ png_write_IEND(png_ptr);
+
+ /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
+ * and restored again in libpng-1.2.30, may cause some applications that
+ * do not set png_ptr->output_flush_fn to crash. If your application
+ * experiences a problem, please try building libpng with
+ * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
+ * png-mng-implement at lists.sf.net .
+ */
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+# ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED
+ png_flush(png_ptr);
+# endif
+#endif
+}
+
+#ifdef PNG_CONVERT_tIME_SUPPORTED
+void PNGAPI
+png_convert_from_struct_tm(png_timep ptime, const struct tm * ttime)
+{
+ png_debug(1, "in png_convert_from_struct_tm");
+
+ ptime->year = (png_uint_16)(1900 + ttime->tm_year);
+ ptime->month = (png_byte)(ttime->tm_mon + 1);
+ ptime->day = (png_byte)ttime->tm_mday;
+ ptime->hour = (png_byte)ttime->tm_hour;
+ ptime->minute = (png_byte)ttime->tm_min;
+ ptime->second = (png_byte)ttime->tm_sec;
+}
+
+void PNGAPI
+png_convert_from_time_t(png_timep ptime, time_t ttime)
+{
+ struct tm *tbuf;
+
+ png_debug(1, "in png_convert_from_time_t");
+
+ tbuf = gmtime(&ttime);
+ if (tbuf == NULL)
+ {
+ /* TODO: add a safe function which takes a png_ptr argument and raises
+ * a png_error if the ttime argument is invalid and the call to gmtime
+ * fails as a consequence.
+ */
+ memset(ptime, 0, sizeof(*ptime));
+ return;
+ }
+
+ png_convert_from_struct_tm(ptime, tbuf);
+}
+#endif
+
+/* Initialize png_ptr structure, and allocate any memory needed */
+PNG_FUNCTION(png_structp,PNGAPI
+png_create_write_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED)
+{
+#ifndef PNG_USER_MEM_SUPPORTED
+ png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
+ error_fn, warn_fn, NULL, NULL, NULL);
+#else
+ return png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
+ warn_fn, NULL, NULL, NULL);
+}
+
+/* Alternate initialize png_ptr structure, and allocate any memory needed */
+PNG_FUNCTION(png_structp,PNGAPI
+png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
+ png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+ png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
+{
+ png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
+ error_fn, warn_fn, mem_ptr, malloc_fn, free_fn);
+#endif /* USER_MEM */
+ if (png_ptr != NULL)
+ {
+ /* Set the zlib control values to defaults; they can be overridden by the
+ * application after the struct has been created.
+ */
+ png_ptr->zbuffer_size = PNG_ZBUF_SIZE;
+
+ /* The 'zlib_strategy' setting is irrelevant because png_default_claim in
+ * pngwutil.c defaults it according to whether or not filters will be
+ * used, and ignores this setting.
+ */
+ png_ptr->zlib_strategy = PNG_Z_DEFAULT_STRATEGY;
+ png_ptr->zlib_level = PNG_Z_DEFAULT_COMPRESSION;
+ png_ptr->zlib_mem_level = 8;
+ png_ptr->zlib_window_bits = 15;
+ png_ptr->zlib_method = 8;
+
+#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+ png_ptr->zlib_text_strategy = PNG_TEXT_Z_DEFAULT_STRATEGY;
+ png_ptr->zlib_text_level = PNG_TEXT_Z_DEFAULT_COMPRESSION;
+ png_ptr->zlib_text_mem_level = 8;
+ png_ptr->zlib_text_window_bits = 15;
+ png_ptr->zlib_text_method = 8;
+#endif /* WRITE_COMPRESSED_TEXT */
+
+ /* This is a highly dubious configuration option; by default it is off,
+ * but it may be appropriate for private builds that are testing
+ * extensions not conformant to the current specification, or of
+ * applications that must not fail to write at all costs!
+ */
+#ifdef PNG_BENIGN_WRITE_ERRORS_SUPPORTED
+ /* In stable builds only warn if an application error can be completely
+ * handled.
+ */
+ png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN;
+#endif
+
+ /* App warnings are warnings in release (or release candidate) builds but
+ * are errors during development.
+ */
+#if PNG_RELEASE_BUILD
+ png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN;
+#endif
+
+ /* TODO: delay this, it can be done in png_init_io() (if the app doesn't
+ * do it itself) avoiding setting the default function if it is not
+ * required.
+ */
+ png_set_write_fn(png_ptr, NULL, NULL, NULL);
+ }
+
+ return png_ptr;
+}
+
+
+/* Write a few rows of image data. If the image is interlaced,
+ * either you will have to write the 7 sub images, or, if you
+ * have called png_set_interlace_handling(), you will have to
+ * "write" the image seven times.
+ */
+void PNGAPI
+png_write_rows(png_structrp png_ptr, png_bytepp row,
+ png_uint_32 num_rows)
+{
+ png_uint_32 i; /* row counter */
+ png_bytepp rp; /* row pointer */
+
+ png_debug(1, "in png_write_rows");
+
+ if (png_ptr == NULL)
+ return;
+
+ /* Loop through the rows */
+ for (i = 0, rp = row; i < num_rows; i++, rp++)
+ {
+ png_write_row(png_ptr, *rp);
+ }
+}
+
+/* Write the image. You only need to call this function once, even
+ * if you are writing an interlaced image.
+ */
+void PNGAPI
+png_write_image(png_structrp png_ptr, png_bytepp image)
+{
+ png_uint_32 i; /* row index */
+ int pass, num_pass; /* pass variables */
+ png_bytepp rp; /* points to current row */
+
+ if (png_ptr == NULL)
+ return;
+
+ png_debug(1, "in png_write_image");
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* Initialize interlace handling. If image is not interlaced,
+ * this will set pass to 1
+ */
+ num_pass = png_set_interlace_handling(png_ptr);
+#else
+ num_pass = 1;
+#endif
+ /* Loop through passes */
+ for (pass = 0; pass < num_pass; pass++)
+ {
+ /* Loop through image */
+ for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
+ {
+ png_write_row(png_ptr, *rp);
+ }
+ }
+}
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+/* Performs intrapixel differencing */
+static void
+png_do_write_intrapixel(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_write_intrapixel");
+
+ if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ {
+ int bytes_per_pixel;
+ png_uint_32 row_width = row_info->width;
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ bytes_per_pixel = 3;
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ bytes_per_pixel = 4;
+
+ else
+ return;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+ {
+ *(rp) = (png_byte)(*rp - *(rp + 1));
+ *(rp + 2) = (png_byte)(*(rp + 2) - *(rp + 1));
+ }
+ }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ else if (row_info->bit_depth == 16)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ bytes_per_pixel = 6;
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ bytes_per_pixel = 8;
+
+ else
+ return;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+ {
+ png_uint_32 s0 = (png_uint_32)(*(rp ) << 8) | *(rp + 1);
+ png_uint_32 s1 = (png_uint_32)(*(rp + 2) << 8) | *(rp + 3);
+ png_uint_32 s2 = (png_uint_32)(*(rp + 4) << 8) | *(rp + 5);
+ png_uint_32 red = (png_uint_32)((s0 - s1) & 0xffffL);
+ png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL);
+ *(rp ) = (png_byte)(red >> 8);
+ *(rp + 1) = (png_byte)red;
+ *(rp + 4) = (png_byte)(blue >> 8);
+ *(rp + 5) = (png_byte)blue;
+ }
+ }
+#endif /* WRITE_16BIT */
+ }
+}
+#endif /* MNG_FEATURES */
+
+/* Called by user to write a row of image data */
+void PNGAPI
+png_write_row(png_structrp png_ptr, png_const_bytep row)
+{
+ /* 1.5.6: moved from png_struct to be a local structure: */
+ png_row_info row_info;
+
+ png_debug2(1, "in png_write_row (row %u, pass %d)",
+ png_ptr->row_number, png_ptr->pass);
+
+ if (png_ptr == NULL)
+ return;
+
+ /* Initialize transformations and other stuff if first time */
+ if (png_ptr->row_number == 0 && png_ptr->pass == 0)
+ {
+ /* Make sure we wrote the header info */
+ if ((png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE) == 0)
+ png_error(png_ptr,
+ "png_write_info was never called before png_write_row");
+
+ /* Check for transforms that have been set but were defined out */
+#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
+ if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
+ png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined");
+#endif
+
+#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
+ if ((png_ptr->transformations & PNG_FILLER) != 0)
+ png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined");
+#endif
+#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
+ defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
+ png_warning(png_ptr,
+ "PNG_WRITE_PACKSWAP_SUPPORTED is not defined");
+#endif
+
+#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
+ if ((png_ptr->transformations & PNG_PACK) != 0)
+ png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined");
+#endif
+
+#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
+ if ((png_ptr->transformations & PNG_SHIFT) != 0)
+ png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined");
+#endif
+
+#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
+ if ((png_ptr->transformations & PNG_BGR) != 0)
+ png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined");
+#endif
+
+#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
+ if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
+ png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined");
+#endif
+
+ png_write_start_row(png_ptr);
+ }
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* If interlaced and not interested in row, return */
+ if (png_ptr->interlaced != 0 &&
+ (png_ptr->transformations & PNG_INTERLACE) != 0)
+ {
+ switch (png_ptr->pass)
+ {
+ case 0:
+ if ((png_ptr->row_number & 0x07) != 0)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 1:
+ if ((png_ptr->row_number & 0x07) != 0 || png_ptr->width < 5)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 2:
+ if ((png_ptr->row_number & 0x07) != 4)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 3:
+ if ((png_ptr->row_number & 0x03) != 0 || png_ptr->width < 3)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 4:
+ if ((png_ptr->row_number & 0x03) != 2)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 5:
+ if ((png_ptr->row_number & 0x01) != 0 || png_ptr->width < 2)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ case 6:
+ if ((png_ptr->row_number & 0x01) == 0)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ break;
+
+ default: /* error: ignore it */
+ break;
+ }
+ }
+#endif
+
+ /* Set up row info for transformations */
+ row_info.color_type = png_ptr->color_type;
+ row_info.width = png_ptr->usr_width;
+ row_info.channels = png_ptr->usr_channels;
+ row_info.bit_depth = png_ptr->usr_bit_depth;
+ row_info.pixel_depth = (png_byte)(row_info.bit_depth * row_info.channels);
+ row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
+
+ png_debug1(3, "row_info->color_type = %d", row_info.color_type);
+ png_debug1(3, "row_info->width = %u", row_info.width);
+ png_debug1(3, "row_info->channels = %d", row_info.channels);
+ png_debug1(3, "row_info->bit_depth = %d", row_info.bit_depth);
+ png_debug1(3, "row_info->pixel_depth = %d", row_info.pixel_depth);
+ png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info.rowbytes);
+
+ /* Copy user's row into buffer, leaving room for filter byte. */
+ memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes);
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* Handle interlacing */
+ if (png_ptr->interlaced && png_ptr->pass < 6 &&
+ (png_ptr->transformations & PNG_INTERLACE) != 0)
+ {
+ png_do_write_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass);
+ /* This should always get caught above, but still ... */
+ if (row_info.width == 0)
+ {
+ png_write_finish_row(png_ptr);
+ return;
+ }
+ }
+#endif
+
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
+ /* Handle other transformations */
+ if (png_ptr->transformations != 0)
+ png_do_write_transformations(png_ptr, &row_info);
+#endif
+
+ /* At this point the row_info pixel depth must match the 'transformed' depth,
+ * which is also the output depth.
+ */
+ if (row_info.pixel_depth != png_ptr->pixel_depth ||
+ row_info.pixel_depth != png_ptr->transformed_pixel_depth)
+ png_error(png_ptr, "internal write transform logic error");
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ /* Write filter_method 64 (intrapixel differencing) only if
+ * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
+ * 2. Libpng did not write a PNG signature (this filter_method is only
+ * used in PNG datastreams that are embedded in MNG datastreams) and
+ * 3. The application called png_permit_mng_features with a mask that
+ * included PNG_FLAG_MNG_FILTER_64 and
+ * 4. The filter_method is 64 and
+ * 5. The color_type is RGB or RGBA
+ */
+ if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
+ (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
+ {
+ /* Intrapixel differencing */
+ png_do_write_intrapixel(&row_info, png_ptr->row_buf + 1);
+ }
+#endif
+
+/* Added at libpng-1.5.10 */
+#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
+ /* Check for out-of-range palette index */
+ if (row_info.color_type == PNG_COLOR_TYPE_PALETTE &&
+ png_ptr->num_palette_max >= 0)
+ png_do_check_palette_indexes(png_ptr, &row_info);
+#endif
+
+ /* Find a filter if necessary, filter the row and write it out. */
+ png_write_find_filter(png_ptr, &row_info);
+
+ if (png_ptr->write_row_fn != NULL)
+ (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
+}
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+/* Set the automatic flush interval or 0 to turn flushing off */
+void PNGAPI
+png_set_flush(png_structrp png_ptr, int nrows)
+{
+ png_debug(1, "in png_set_flush");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->flush_dist = (nrows < 0 ? 0 : (png_uint_32)nrows);
+}
+
+/* Flush the current output buffers now */
+void PNGAPI
+png_write_flush(png_structrp png_ptr)
+{
+ png_debug(1, "in png_write_flush");
+
+ if (png_ptr == NULL)
+ return;
+
+ /* We have already written out all of the data */
+ if (png_ptr->row_number >= png_ptr->num_rows)
+ return;
+
+ png_compress_IDAT(png_ptr, NULL, 0, Z_SYNC_FLUSH);
+ png_ptr->flush_rows = 0;
+ png_flush(png_ptr);
+}
+#endif /* WRITE_FLUSH */
+
+/* Free any memory used in png_ptr struct without freeing the struct itself. */
+static void
+png_write_destroy(png_structrp png_ptr)
+{
+ png_debug(1, "in png_write_destroy");
+
+ /* Free any memory zlib uses */
+ if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0)
+ deflateEnd(&png_ptr->zstream);
+
+ /* Free our memory. png_free checks NULL for us. */
+ png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list);
+ png_free(png_ptr, png_ptr->row_buf);
+ png_ptr->row_buf = NULL;
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ png_free(png_ptr, png_ptr->prev_row);
+ png_free(png_ptr, png_ptr->try_row);
+ png_free(png_ptr, png_ptr->tst_row);
+ png_ptr->prev_row = NULL;
+ png_ptr->try_row = NULL;
+ png_ptr->tst_row = NULL;
+#endif
+
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+ png_free(png_ptr, png_ptr->chunk_list);
+ png_ptr->chunk_list = NULL;
+#endif
+
+ /* The error handling and memory handling information is left intact at this
+ * point: the jmp_buf may still have to be freed. See png_destroy_png_struct
+ * for how this happens.
+ */
+}
+
+/* Free all memory used by the write.
+ * In libpng 1.6.0 this API changed quietly to no longer accept a NULL value for
+ * *png_ptr_ptr. Prior to 1.6.0 it would accept such a value and it would free
+ * the passed in info_structs but it would quietly fail to free any of the data
+ * inside them. In 1.6.0 it quietly does nothing (it has to be quiet because it
+ * has no png_ptr.)
+ */
+void PNGAPI
+png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
+{
+ png_debug(1, "in png_destroy_write_struct");
+
+ if (png_ptr_ptr != NULL)
+ {
+ png_structrp png_ptr = *png_ptr_ptr;
+
+ if (png_ptr != NULL) /* added in libpng 1.6.0 */
+ {
+ png_destroy_info_struct(png_ptr, info_ptr_ptr);
+
+ *png_ptr_ptr = NULL;
+ png_write_destroy(png_ptr);
+ png_destroy_png_struct(png_ptr);
+ }
+ }
+}
+
+/* Allow the application to select one or more row filters to use. */
+void PNGAPI
+png_set_filter(png_structrp png_ptr, int method, int filters)
+{
+ png_debug(1, "in png_set_filter");
+
+ if (png_ptr == NULL)
+ return;
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
+ (method == PNG_INTRAPIXEL_DIFFERENCING))
+ method = PNG_FILTER_TYPE_BASE;
+
+#endif
+ if (method == PNG_FILTER_TYPE_BASE)
+ {
+ switch (filters & (PNG_ALL_FILTERS | 0x07))
+ {
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ case 5:
+ case 6:
+ case 7: png_app_error(png_ptr, "Unknown row filter for method 0");
+#endif /* WRITE_FILTER */
+ /* FALLTHROUGH */
+ case PNG_FILTER_VALUE_NONE:
+ png_ptr->do_filter = PNG_FILTER_NONE; break;
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ case PNG_FILTER_VALUE_SUB:
+ png_ptr->do_filter = PNG_FILTER_SUB; break;
+
+ case PNG_FILTER_VALUE_UP:
+ png_ptr->do_filter = PNG_FILTER_UP; break;
+
+ case PNG_FILTER_VALUE_AVG:
+ png_ptr->do_filter = PNG_FILTER_AVG; break;
+
+ case PNG_FILTER_VALUE_PAETH:
+ png_ptr->do_filter = PNG_FILTER_PAETH; break;
+
+ default:
+ png_ptr->do_filter = (png_byte)filters; break;
+#else
+ default:
+ png_app_error(png_ptr, "Unknown row filter for method 0");
+#endif /* WRITE_FILTER */
+ }
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ /* If we have allocated the row_buf, this means we have already started
+ * with the image and we should have allocated all of the filter buffers
+ * that have been selected. If prev_row isn't already allocated, then
+ * it is too late to start using the filters that need it, since we
+ * will be missing the data in the previous row. If an application
+ * wants to start and stop using particular filters during compression,
+ * it should start out with all of the filters, and then remove them
+ * or add them back after the start of compression.
+ *
+ * NOTE: this is a nasty constraint on the code, because it means that the
+ * prev_row buffer must be maintained even if there are currently no
+ * 'prev_row' requiring filters active.
+ */
+ if (png_ptr->row_buf != NULL)
+ {
+ int num_filters;
+ png_alloc_size_t buf_size;
+
+ /* Repeat the checks in png_write_start_row; 1 pixel high or wide
+ * images cannot benefit from certain filters. If this isn't done here
+ * the check below will fire on 1 pixel high images.
+ */
+ if (png_ptr->height == 1)
+ filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH);
+
+ if (png_ptr->width == 1)
+ filters &= ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH);
+
+ if ((filters & (PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH)) != 0
+ && png_ptr->prev_row == NULL)
+ {
+ /* This is the error case, however it is benign - the previous row
+ * is not available so the filter can't be used. Just warn here.
+ */
+ png_app_warning(png_ptr,
+ "png_set_filter: UP/AVG/PAETH cannot be added after start");
+ filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH);
+ }
+
+ num_filters = 0;
+
+ if (filters & PNG_FILTER_SUB)
+ num_filters++;
+
+ if (filters & PNG_FILTER_UP)
+ num_filters++;
+
+ if (filters & PNG_FILTER_AVG)
+ num_filters++;
+
+ if (filters & PNG_FILTER_PAETH)
+ num_filters++;
+
+ /* Allocate needed row buffers if they have not already been
+ * allocated.
+ */
+ buf_size = PNG_ROWBYTES(png_ptr->usr_channels * png_ptr->usr_bit_depth,
+ png_ptr->width) + 1;
+
+ if (png_ptr->try_row == NULL)
+ png_ptr->try_row = png_voidcast(png_bytep,
+ png_malloc(png_ptr, buf_size));
+
+ if (num_filters > 1)
+ {
+ if (png_ptr->tst_row == NULL)
+ png_ptr->tst_row = png_voidcast(png_bytep,
+ png_malloc(png_ptr, buf_size));
+ }
+ }
+ png_ptr->do_filter = (png_byte)filters;
+#endif
+ }
+ else
+ png_error(png_ptr, "Unknown custom filter method");
+}
+
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
+/* Provide floating and fixed point APIs */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_filter_heuristics(png_structrp png_ptr, int heuristic_method,
+ int num_weights, png_const_doublep filter_weights,
+ png_const_doublep filter_costs)
+{
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(heuristic_method)
+ PNG_UNUSED(num_weights)
+ PNG_UNUSED(filter_weights)
+ PNG_UNUSED(filter_costs)
+}
+#endif /* FLOATING_POINT */
+
+#ifdef PNG_FIXED_POINT_SUPPORTED
+void PNGAPI
+png_set_filter_heuristics_fixed(png_structrp png_ptr, int heuristic_method,
+ int num_weights, png_const_fixed_point_p filter_weights,
+ png_const_fixed_point_p filter_costs)
+{
+ PNG_UNUSED(png_ptr)
+ PNG_UNUSED(heuristic_method)
+ PNG_UNUSED(num_weights)
+ PNG_UNUSED(filter_weights)
+ PNG_UNUSED(filter_costs)
+}
+#endif /* FIXED_POINT */
+#endif /* WRITE_WEIGHTED_FILTER */
+
+#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
+void PNGAPI
+png_set_compression_level(png_structrp png_ptr, int level)
+{
+ png_debug(1, "in png_set_compression_level");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->zlib_level = level;
+}
+
+void PNGAPI
+png_set_compression_mem_level(png_structrp png_ptr, int mem_level)
+{
+ png_debug(1, "in png_set_compression_mem_level");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->zlib_mem_level = mem_level;
+}
+
+void PNGAPI
+png_set_compression_strategy(png_structrp png_ptr, int strategy)
+{
+ png_debug(1, "in png_set_compression_strategy");
+
+ if (png_ptr == NULL)
+ return;
+
+ /* The flag setting here prevents the libpng dynamic selection of strategy.
+ */
+ png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
+ png_ptr->zlib_strategy = strategy;
+}
+
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
+void PNGAPI
+png_set_compression_window_bits(png_structrp png_ptr, int window_bits)
+{
+ png_debug(1, "in png_set_compression_window_bits");
+
+ if (png_ptr == NULL)
+ return;
+
+ /* Prior to 1.6.0 this would warn but then set the window_bits value. This
+ * meant that negative window bits values could be selected that would cause
+ * libpng to write a non-standard PNG file with raw deflate or gzip
+ * compressed IDAT or ancillary chunks. Such files can be read and there is
+ * no warning on read, so this seems like a very bad idea.
+ */
+ if (window_bits > 15)
+ {
+ png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
+ window_bits = 15;
+ }
+
+ else if (window_bits < 8)
+ {
+ png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
+ window_bits = 8;
+ }
+
+ png_ptr->zlib_window_bits = window_bits;
+}
+
+void PNGAPI
+png_set_compression_method(png_structrp png_ptr, int method)
+{
+ png_debug(1, "in png_set_compression_method");
+
+ if (png_ptr == NULL)
+ return;
+
+ /* This would produce an invalid PNG file if it worked, but it doesn't and
+ * deflate will fault it, so it is harmless to just warn here.
+ */
+ if (method != 8)
+ png_warning(png_ptr, "Only compression method 8 is supported by PNG");
+
+ png_ptr->zlib_method = method;
+}
+#endif /* WRITE_CUSTOMIZE_COMPRESSION */
+
+/* The following were added to libpng-1.5.4 */
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+void PNGAPI
+png_set_text_compression_level(png_structrp png_ptr, int level)
+{
+ png_debug(1, "in png_set_text_compression_level");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->zlib_text_level = level;
+}
+
+void PNGAPI
+png_set_text_compression_mem_level(png_structrp png_ptr, int mem_level)
+{
+ png_debug(1, "in png_set_text_compression_mem_level");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->zlib_text_mem_level = mem_level;
+}
+
+void PNGAPI
+png_set_text_compression_strategy(png_structrp png_ptr, int strategy)
+{
+ png_debug(1, "in png_set_text_compression_strategy");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->zlib_text_strategy = strategy;
+}
+
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
+void PNGAPI
+png_set_text_compression_window_bits(png_structrp png_ptr, int window_bits)
+{
+ png_debug(1, "in png_set_text_compression_window_bits");
+
+ if (png_ptr == NULL)
+ return;
+
+ if (window_bits > 15)
+ {
+ png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
+ window_bits = 15;
+ }
+
+ else if (window_bits < 8)
+ {
+ png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
+ window_bits = 8;
+ }
+
+ png_ptr->zlib_text_window_bits = window_bits;
+}
+
+void PNGAPI
+png_set_text_compression_method(png_structrp png_ptr, int method)
+{
+ png_debug(1, "in png_set_text_compression_method");
+
+ if (png_ptr == NULL)
+ return;
+
+ if (method != 8)
+ png_warning(png_ptr, "Only compression method 8 is supported by PNG");
+
+ png_ptr->zlib_text_method = method;
+}
+#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
+/* end of API added to libpng-1.5.4 */
+
+void PNGAPI
+png_set_write_status_fn(png_structrp png_ptr, png_write_status_ptr write_row_fn)
+{
+ png_debug(1, "in png_set_write_status_fn");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->write_row_fn = write_row_fn;
+}
+
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+void PNGAPI
+png_set_write_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr
+ write_user_transform_fn)
+{
+ png_debug(1, "in png_set_write_user_transform_fn");
+
+ if (png_ptr == NULL)
+ return;
+
+ png_ptr->transformations |= PNG_USER_TRANSFORM;
+ png_ptr->write_user_transform_fn = write_user_transform_fn;
+}
+#endif
+
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+void PNGAPI
+png_write_png(png_structrp png_ptr, png_inforp info_ptr,
+ int transforms, voidp params)
+{
+ png_debug(1, "in png_write_png");
+
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ if ((info_ptr->valid & PNG_INFO_IDAT) == 0)
+ {
+ png_app_error(png_ptr, "no rows for png_write_image to write");
+ return;
+ }
+
+ /* Write the file header information. */
+ png_write_info(png_ptr, info_ptr);
+
+ /* ------ these transformations don't touch the info structure ------- */
+
+ /* Invert monochrome pixels */
+ if ((transforms & PNG_TRANSFORM_INVERT_MONO) != 0)
+#ifdef PNG_WRITE_INVERT_SUPPORTED
+ png_set_invert_mono(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_MONO not supported");
+#endif
+
+ /* Shift the pixels up to a legal bit depth and fill in
+ * as appropriate to correctly scale the image.
+ */
+ if ((transforms & PNG_TRANSFORM_SHIFT) != 0)
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+ if ((info_ptr->valid & PNG_INFO_sBIT) != 0)
+ png_set_shift(png_ptr, &info_ptr->sig_bit);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported");
+#endif
+
+ /* Pack pixels into bytes */
+ if ((transforms & PNG_TRANSFORM_PACKING) != 0)
+#ifdef PNG_WRITE_PACK_SUPPORTED
+ png_set_packing(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_PACKING not supported");
+#endif
+
+ /* Swap location of alpha bytes from ARGB to RGBA */
+ if ((transforms & PNG_TRANSFORM_SWAP_ALPHA) != 0)
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+ png_set_swap_alpha(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ALPHA not supported");
+#endif
+
+ /* Remove a filler (X) from XRGB/RGBX/AG/GA into to convert it into
+ * RGB, note that the code expects the input color type to be G or RGB; no
+ * alpha channel.
+ */
+ if ((transforms & (PNG_TRANSFORM_STRIP_FILLER_AFTER|
+ PNG_TRANSFORM_STRIP_FILLER_BEFORE)) != 0)
+ {
+#ifdef PNG_WRITE_FILLER_SUPPORTED
+ if ((transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER) != 0)
+ {
+ if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0)
+ png_app_error(png_ptr,
+ "PNG_TRANSFORM_STRIP_FILLER: BEFORE+AFTER not supported");
+
+ /* Continue if ignored - this is the pre-1.6.10 behavior */
+ png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
+ }
+
+ else if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0)
+ png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_FILLER not supported");
+#endif
+ }
+
+ /* Flip BGR pixels to RGB */
+ if ((transforms & PNG_TRANSFORM_BGR) != 0)
+#ifdef PNG_WRITE_BGR_SUPPORTED
+ png_set_bgr(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_BGR not supported");
+#endif
+
+ /* Swap bytes of 16-bit files to most significant byte first */
+ if ((transforms & PNG_TRANSFORM_SWAP_ENDIAN) != 0)
+#ifdef PNG_WRITE_SWAP_SUPPORTED
+ png_set_swap(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ENDIAN not supported");
+#endif
+
+ /* Swap bits of 1-bit, 2-bit, 4-bit packed pixel formats */
+ if ((transforms & PNG_TRANSFORM_PACKSWAP) != 0)
+#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
+ png_set_packswap(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_PACKSWAP not supported");
+#endif
+
+ /* Invert the alpha channel from opacity to transparency */
+ if ((transforms & PNG_TRANSFORM_INVERT_ALPHA) != 0)
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+ png_set_invert_alpha(png_ptr);
+#else
+ png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_ALPHA not supported");
+#endif
+
+ /* ----------------------- end of transformations ------------------- */
+
+ /* Write the bits */
+ png_write_image(png_ptr, info_ptr->row_pointers);
+
+ /* It is REQUIRED to call this to finish writing the rest of the file */
+ png_write_end(png_ptr, info_ptr);
+
+ PNG_UNUSED(params)
+}
+#endif
+
+
+#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
+/* Initialize the write structure - general purpose utility. */
+static int
+png_image_write_init(png_imagep image)
+{
+ png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, image,
+ png_safe_error, png_safe_warning);
+
+ if (png_ptr != NULL)
+ {
+ png_infop info_ptr = png_create_info_struct(png_ptr);
+
+ if (info_ptr != NULL)
+ {
+ png_controlp control = png_voidcast(png_controlp,
+ png_malloc_warn(png_ptr, (sizeof *control)));
+
+ if (control != NULL)
+ {
+ memset(control, 0, (sizeof *control));
+
+ control->png_ptr = png_ptr;
+ control->info_ptr = info_ptr;
+ control->for_write = 1;
+
+ image->opaque = control;
+ return 1;
+ }
+
+ /* Error clean up */
+ png_destroy_info_struct(png_ptr, &info_ptr);
+ }
+
+ png_destroy_write_struct(&png_ptr, NULL);
+ }
+
+ return png_image_error(image, "png_image_write_: out of memory");
+}
+
+/* Arguments to png_image_write_main: */
+typedef struct
+{
+ /* Arguments: */
+ png_imagep image;
+ png_const_voidp buffer;
+ png_int_32 row_stride;
+ png_const_voidp colormap;
+ int convert_to_8bit;
+ /* Local variables: */
+ png_const_voidp first_row;
+ ptrdiff_t row_bytes;
+ png_voidp local_row;
+ /* Byte count for memory writing */
+ png_bytep memory;
+ png_alloc_size_t memory_bytes; /* not used for STDIO */
+ png_alloc_size_t output_bytes; /* running total */
+} png_image_write_control;
+
+/* Write png_uint_16 input to a 16-bit PNG; the png_ptr has already been set to
+ * do any necessary byte swapping. The component order is defined by the
+ * png_image format value.
+ */
+static int
+png_write_image_16bit(png_voidp argument)
+{
+ png_image_write_control *display = png_voidcast(png_image_write_control*,
+ argument);
+ png_imagep image = display->image;
+ png_structrp png_ptr = image->opaque->png_ptr;
+
+ png_const_uint_16p input_row = png_voidcast(png_const_uint_16p,
+ display->first_row);
+ png_uint_16p output_row = png_voidcast(png_uint_16p, display->local_row);
+ png_uint_16p row_end;
+ unsigned int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ?
+ 3 : 1;
+ int aindex = 0;
+ png_uint_32 y = image->height;
+
+ if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ {
+# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
+ if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0)
+ {
+ aindex = -1;
+ ++input_row; /* To point to the first component */
+ ++output_row;
+ }
+ else
+ aindex = (int)channels;
+# else
+ aindex = (int)channels;
+# endif
+ }
+
+ else
+ png_error(png_ptr, "png_write_image: internal call error");
+
+ /* Work out the output row end and count over this, note that the increment
+ * above to 'row' means that row_end can actually be beyond the end of the
+ * row; this is correct.
+ */
+ row_end = output_row + image->width * (channels+1);
+
+ for (; y > 0; --y)
+ {
+ png_const_uint_16p in_ptr = input_row;
+ png_uint_16p out_ptr = output_row;
+
+ while (out_ptr < row_end)
+ {
+ png_uint_16 alpha = in_ptr[aindex];
+ png_uint_32 reciprocal = 0;
+ int c;
+
+ out_ptr[aindex] = alpha;
+
+ /* Calculate a reciprocal. The correct calculation is simply
+ * component/alpha*65535 << 15. (I.e. 15 bits of precision); this
+ * allows correct rounding by adding .5 before the shift. 'reciprocal'
+ * is only initialized when required.
+ */
+ if (alpha > 0 && alpha < 65535)
+ reciprocal = ((0xffff<<15)+(alpha>>1))/alpha;
+
+ c = (int)channels;
+ do /* always at least one channel */
+ {
+ png_uint_16 component = *in_ptr++;
+
+ /* The following gives 65535 for an alpha of 0, which is fine,
+ * otherwise if 0/0 is represented as some other value there is more
+ * likely to be a discontinuity which will probably damage
+ * compression when moving from a fully transparent area to a
+ * nearly transparent one. (The assumption here is that opaque
+ * areas tend not to be 0 intensity.)
+ */
+ if (component >= alpha)
+ component = 65535;
+
+ /* component 0 && alpha < 65535)
+ {
+ png_uint_32 calc = component * reciprocal;
+ calc += 16384; /* round to nearest */
+ component = (png_uint_16)(calc >> 15);
+ }
+
+ *out_ptr++ = component;
+ }
+ while (--c > 0);
+
+ /* Skip to next component (skip the intervening alpha channel) */
+ ++in_ptr;
+ ++out_ptr;
+ }
+
+ png_write_row(png_ptr, png_voidcast(png_const_bytep, display->local_row));
+ input_row += (png_uint_16)display->row_bytes/(sizeof (png_uint_16));
+ }
+
+ return 1;
+}
+
+/* Given 16-bit input (1 to 4 channels) write 8-bit output. If an alpha channel
+ * is present it must be removed from the components, the components are then
+ * written in sRGB encoding. No components are added or removed.
+ *
+ * Calculate an alpha reciprocal to reverse pre-multiplication. As above the
+ * calculation can be done to 15 bits of accuracy; however, the output needs to
+ * be scaled in the range 0..255*65535, so include that scaling here.
+ */
+# define UNP_RECIPROCAL(alpha) ((((0xffff*0xff)<<7)+((alpha)>>1))/(alpha))
+
+static png_byte
+png_unpremultiply(png_uint_32 component, png_uint_32 alpha,
+ png_uint_32 reciprocal/*from the above macro*/)
+{
+ /* The following gives 1.0 for an alpha of 0, which is fine, otherwise if 0/0
+ * is represented as some other value there is more likely to be a
+ * discontinuity which will probably damage compression when moving from a
+ * fully transparent area to a nearly transparent one. (The assumption here
+ * is that opaque areas tend not to be 0 intensity.)
+ *
+ * There is a rounding problem here; if alpha is less than 128 it will end up
+ * as 0 when scaled to 8 bits. To avoid introducing spurious colors into the
+ * output change for this too.
+ */
+ if (component >= alpha || alpha < 128)
+ return 255;
+
+ /* component 0)
+ {
+ /* The test is that alpha/257 (rounded) is less than 255, the first value
+ * that becomes 255 is 65407.
+ * NOTE: this must agree with the PNG_DIV257 macro (which must, therefore,
+ * be exact!) [Could also test reciprocal != 0]
+ */
+ if (alpha < 65407)
+ {
+ component *= reciprocal;
+ component += 64; /* round to nearest */
+ component >>= 7;
+ }
+
+ else
+ component *= 255;
+
+ /* Convert the component to sRGB. */
+ return (png_byte)PNG_sRGB_FROM_LINEAR(component);
+ }
+
+ else
+ return 0;
+}
+
+static int
+png_write_image_8bit(png_voidp argument)
+{
+ png_image_write_control *display = png_voidcast(png_image_write_control*,
+ argument);
+ png_imagep image = display->image;
+ png_structrp png_ptr = image->opaque->png_ptr;
+
+ png_const_uint_16p input_row = png_voidcast(png_const_uint_16p,
+ display->first_row);
+ png_bytep output_row = png_voidcast(png_bytep, display->local_row);
+ png_uint_32 y = image->height;
+ unsigned int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ?
+ 3 : 1;
+
+ if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ {
+ png_bytep row_end;
+ int aindex;
+
+# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
+ if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0)
+ {
+ aindex = -1;
+ ++input_row; /* To point to the first component */
+ ++output_row;
+ }
+
+ else
+# endif
+ aindex = (int)channels;
+
+ /* Use row_end in place of a loop counter: */
+ row_end = output_row + image->width * (channels+1);
+
+ for (; y > 0; --y)
+ {
+ png_const_uint_16p in_ptr = input_row;
+ png_bytep out_ptr = output_row;
+
+ while (out_ptr < row_end)
+ {
+ png_uint_16 alpha = in_ptr[aindex];
+ png_byte alphabyte = (png_byte)PNG_DIV257(alpha);
+ png_uint_32 reciprocal = 0;
+ int c;
+
+ /* Scale and write the alpha channel. */
+ out_ptr[aindex] = alphabyte;
+
+ if (alphabyte > 0 && alphabyte < 255)
+ reciprocal = UNP_RECIPROCAL(alpha);
+
+ c = (int)channels;
+ do /* always at least one channel */
+ *out_ptr++ = png_unpremultiply(*in_ptr++, alpha, reciprocal);
+ while (--c > 0);
+
+ /* Skip to next component (skip the intervening alpha channel) */
+ ++in_ptr;
+ ++out_ptr;
+ } /* while out_ptr < row_end */
+
+ png_write_row(png_ptr, png_voidcast(png_const_bytep,
+ display->local_row));
+ input_row += (png_uint_16)display->row_bytes/(sizeof (png_uint_16));
+ } /* while y */
+ }
+
+ else
+ {
+ /* No alpha channel, so the row_end really is the end of the row and it
+ * is sufficient to loop over the components one by one.
+ */
+ png_bytep row_end = output_row + image->width * channels;
+
+ for (; y > 0; --y)
+ {
+ png_const_uint_16p in_ptr = input_row;
+ png_bytep out_ptr = output_row;
+
+ while (out_ptr < row_end)
+ {
+ png_uint_32 component = *in_ptr++;
+
+ component *= 255;
+ *out_ptr++ = (png_byte)PNG_sRGB_FROM_LINEAR(component);
+ }
+
+ png_write_row(png_ptr, output_row);
+ input_row += (png_uint_16)display->row_bytes/(sizeof (png_uint_16));
+ }
+ }
+
+ return 1;
+}
+
+static void
+png_image_set_PLTE(png_image_write_control *display)
+{
+ png_imagep image = display->image;
+ const void *cmap = display->colormap;
+ int entries = image->colormap_entries > 256 ? 256 :
+ (int)image->colormap_entries;
+
+ /* NOTE: the caller must check for cmap != NULL and entries != 0 */
+ png_uint_32 format = image->format;
+ unsigned int channels = PNG_IMAGE_SAMPLE_CHANNELS(format);
+
+# if defined(PNG_FORMAT_BGR_SUPPORTED) &&\
+ defined(PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED)
+ int afirst = (format & PNG_FORMAT_FLAG_AFIRST) != 0 &&
+ (format & PNG_FORMAT_FLAG_ALPHA) != 0;
+# else
+# define afirst 0
+# endif
+
+# ifdef PNG_FORMAT_BGR_SUPPORTED
+ int bgr = (format & PNG_FORMAT_FLAG_BGR) != 0 ? 2 : 0;
+# else
+# define bgr 0
+# endif
+
+ int i, num_trans;
+ png_color palette[256];
+ png_byte tRNS[256];
+
+ memset(tRNS, 255, (sizeof tRNS));
+ memset(palette, 0, (sizeof palette));
+
+ for (i=num_trans=0; i= 3) /* RGB */
+ {
+ palette[i].blue = (png_byte)PNG_sRGB_FROM_LINEAR(255 *
+ entry[(2 ^ bgr)]);
+ palette[i].green = (png_byte)PNG_sRGB_FROM_LINEAR(255 *
+ entry[1]);
+ palette[i].red = (png_byte)PNG_sRGB_FROM_LINEAR(255 *
+ entry[bgr]);
+ }
+
+ else /* Gray */
+ palette[i].blue = palette[i].red = palette[i].green =
+ (png_byte)PNG_sRGB_FROM_LINEAR(255 * *entry);
+ }
+
+ else /* alpha */
+ {
+ png_uint_16 alpha = entry[afirst ? 0 : channels-1];
+ png_byte alphabyte = (png_byte)PNG_DIV257(alpha);
+ png_uint_32 reciprocal = 0;
+
+ /* Calculate a reciprocal, as in the png_write_image_8bit code above
+ * this is designed to produce a value scaled to 255*65535 when
+ * divided by 128 (i.e. asr 7).
+ */
+ if (alphabyte > 0 && alphabyte < 255)
+ reciprocal = (((0xffff*0xff)<<7)+(alpha>>1))/alpha;
+
+ tRNS[i] = alphabyte;
+ if (alphabyte < 255)
+ num_trans = i+1;
+
+ if (channels >= 3) /* RGB */
+ {
+ palette[i].blue = png_unpremultiply(entry[afirst + (2 ^ bgr)],
+ alpha, reciprocal);
+ palette[i].green = png_unpremultiply(entry[afirst + 1], alpha,
+ reciprocal);
+ palette[i].red = png_unpremultiply(entry[afirst + bgr], alpha,
+ reciprocal);
+ }
+
+ else /* gray */
+ palette[i].blue = palette[i].red = palette[i].green =
+ png_unpremultiply(entry[afirst], alpha, reciprocal);
+ }
+ }
+
+ else /* Color-map has sRGB values */
+ {
+ png_const_bytep entry = png_voidcast(png_const_bytep, cmap);
+
+ entry += (unsigned int)i * channels;
+
+ switch (channels)
+ {
+ case 4:
+ tRNS[i] = entry[afirst ? 0 : 3];
+ if (tRNS[i] < 255)
+ num_trans = i+1;
+ /* FALLTHROUGH */
+ case 3:
+ palette[i].blue = entry[afirst + (2 ^ bgr)];
+ palette[i].green = entry[afirst + 1];
+ palette[i].red = entry[afirst + bgr];
+ break;
+
+ case 2:
+ tRNS[i] = entry[1 ^ afirst];
+ if (tRNS[i] < 255)
+ num_trans = i+1;
+ /* FALLTHROUGH */
+ case 1:
+ palette[i].blue = palette[i].red = palette[i].green =
+ entry[afirst];
+ break;
+
+ default:
+ break;
+ }
+ }
+ }
+
+# ifdef afirst
+# undef afirst
+# endif
+# ifdef bgr
+# undef bgr
+# endif
+
+ png_set_PLTE(image->opaque->png_ptr, image->opaque->info_ptr, palette,
+ entries);
+
+ if (num_trans > 0)
+ png_set_tRNS(image->opaque->png_ptr, image->opaque->info_ptr, tRNS,
+ num_trans, NULL);
+
+ image->colormap_entries = (png_uint_32)entries;
+}
+
+static int
+png_image_write_main(png_voidp argument)
+{
+ png_image_write_control *display = png_voidcast(png_image_write_control*,
+ argument);
+ png_imagep image = display->image;
+ png_structrp png_ptr = image->opaque->png_ptr;
+ png_inforp info_ptr = image->opaque->info_ptr;
+ png_uint_32 format = image->format;
+
+ /* The following four ints are actually booleans */
+ int colormap = (format & PNG_FORMAT_FLAG_COLORMAP);
+ int linear = !colormap && (format & PNG_FORMAT_FLAG_LINEAR); /* input */
+ int alpha = !colormap && (format & PNG_FORMAT_FLAG_ALPHA);
+ int write_16bit = linear && (display->convert_to_8bit == 0);
+
+# ifdef PNG_BENIGN_ERRORS_SUPPORTED
+ /* Make sure we error out on any bad situation */
+ png_set_benign_errors(png_ptr, 0/*error*/);
+# endif
+
+ /* Default the 'row_stride' parameter if required, also check the row stride
+ * and total image size to ensure that they are within the system limits.
+ */
+ {
+ unsigned int channels = PNG_IMAGE_PIXEL_CHANNELS(image->format);
+
+ if (image->width <= 0x7fffffffU/channels) /* no overflow */
+ {
+ png_uint_32 check;
+ png_uint_32 png_row_stride = image->width * channels;
+
+ if (display->row_stride == 0)
+ display->row_stride = (png_int_32)/*SAFE*/png_row_stride;
+
+ if (display->row_stride < 0)
+ check = (png_uint_32)(-display->row_stride);
+
+ else
+ check = (png_uint_32)display->row_stride;
+
+ if (check >= png_row_stride)
+ {
+ /* Now check for overflow of the image buffer calculation; this
+ * limits the whole image size to 32 bits for API compatibility with
+ * the current, 32-bit, PNG_IMAGE_BUFFER_SIZE macro.
+ */
+ if (image->height > 0xffffffffU/png_row_stride)
+ png_error(image->opaque->png_ptr, "memory image too large");
+ }
+
+ else
+ png_error(image->opaque->png_ptr, "supplied row stride too small");
+ }
+
+ else
+ png_error(image->opaque->png_ptr, "image row stride too large");
+ }
+
+ /* Set the required transforms then write the rows in the correct order. */
+ if ((format & PNG_FORMAT_FLAG_COLORMAP) != 0)
+ {
+ if (display->colormap != NULL && image->colormap_entries > 0)
+ {
+ png_uint_32 entries = image->colormap_entries;
+
+ png_set_IHDR(png_ptr, info_ptr, image->width, image->height,
+ entries > 16 ? 8 : (entries > 4 ? 4 : (entries > 2 ? 2 : 1)),
+ PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE,
+ PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+
+ png_image_set_PLTE(display);
+ }
+
+ else
+ png_error(image->opaque->png_ptr,
+ "no color-map for color-mapped image");
+ }
+
+ else
+ png_set_IHDR(png_ptr, info_ptr, image->width, image->height,
+ write_16bit ? 16 : 8,
+ ((format & PNG_FORMAT_FLAG_COLOR) ? PNG_COLOR_MASK_COLOR : 0) +
+ ((format & PNG_FORMAT_FLAG_ALPHA) ? PNG_COLOR_MASK_ALPHA : 0),
+ PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+
+ /* Counter-intuitively the data transformations must be called *after*
+ * png_write_info, not before as in the read code, but the 'set' functions
+ * must still be called before. Just set the color space information, never
+ * write an interlaced image.
+ */
+
+ if (write_16bit != 0)
+ {
+ /* The gamma here is 1.0 (linear) and the cHRM chunk matches sRGB. */
+ png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_LINEAR);
+
+ if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0)
+ png_set_cHRM_fixed(png_ptr, info_ptr,
+ /* color x y */
+ /* white */ 31270, 32900,
+ /* red */ 64000, 33000,
+ /* green */ 30000, 60000,
+ /* blue */ 15000, 6000
+ );
+ }
+
+ else if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0)
+ png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_PERCEPTUAL);
+
+ /* Else writing an 8-bit file and the *colors* aren't sRGB, but the 8-bit
+ * space must still be gamma encoded.
+ */
+ else
+ png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_sRGB_INVERSE);
+
+ /* Write the file header. */
+ png_write_info(png_ptr, info_ptr);
+
+ /* Now set up the data transformations (*after* the header is written),
+ * remove the handled transformations from the 'format' flags for checking.
+ *
+ * First check for a little endian system if writing 16-bit files.
+ */
+ if (write_16bit != 0)
+ {
+ png_uint_16 le = 0x0001;
+
+ if ((*(png_const_bytep) & le) != 0)
+ png_set_swap(png_ptr);
+ }
+
+# ifdef PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED
+ if ((format & PNG_FORMAT_FLAG_BGR) != 0)
+ {
+ if (colormap == 0 && (format & PNG_FORMAT_FLAG_COLOR) != 0)
+ png_set_bgr(png_ptr);
+ format &= ~PNG_FORMAT_FLAG_BGR;
+ }
+# endif
+
+# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
+ if ((format & PNG_FORMAT_FLAG_AFIRST) != 0)
+ {
+ if (colormap == 0 && (format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ png_set_swap_alpha(png_ptr);
+ format &= ~PNG_FORMAT_FLAG_AFIRST;
+ }
+# endif
+
+ /* If there are 16 or fewer color-map entries we wrote a lower bit depth
+ * above, but the application data is still byte packed.
+ */
+ if (colormap != 0 && image->colormap_entries <= 16)
+ png_set_packing(png_ptr);
+
+ /* That should have handled all (both) the transforms. */
+ if ((format & ~(png_uint_32)(PNG_FORMAT_FLAG_COLOR | PNG_FORMAT_FLAG_LINEAR |
+ PNG_FORMAT_FLAG_ALPHA | PNG_FORMAT_FLAG_COLORMAP)) != 0)
+ png_error(png_ptr, "png_write_image: unsupported transformation");
+
+ {
+ png_const_bytep row = png_voidcast(png_const_bytep, display->buffer);
+ ptrdiff_t row_bytes = display->row_stride;
+
+ if (linear != 0)
+ row_bytes *= (sizeof (png_uint_16));
+
+ if (row_bytes < 0)
+ row += (image->height-1) * (-row_bytes);
+
+ display->first_row = row;
+ display->row_bytes = row_bytes;
+ }
+
+ /* Apply 'fast' options if the flag is set. */
+ if ((image->flags & PNG_IMAGE_FLAG_FAST) != 0)
+ {
+ png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_NO_FILTERS);
+ /* NOTE: determined by experiment using pngstest, this reflects some
+ * balance between the time to write the image once and the time to read
+ * it about 50 times. The speed-up in pngstest was about 10-20% of the
+ * total (user) time on a heavily loaded system.
+ */
+# ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
+ png_set_compression_level(png_ptr, 3);
+# endif
+ }
+
+ /* Check for the cases that currently require a pre-transform on the row
+ * before it is written. This only applies when the input is 16-bit and
+ * either there is an alpha channel or it is converted to 8-bit.
+ */
+ if ((linear != 0 && alpha != 0 ) ||
+ (colormap == 0 && display->convert_to_8bit != 0))
+ {
+ png_bytep row = png_voidcast(png_bytep, png_malloc(png_ptr,
+ png_get_rowbytes(png_ptr, info_ptr)));
+ int result;
+
+ display->local_row = row;
+ if (write_16bit != 0)
+ result = png_safe_execute(image, png_write_image_16bit, display);
+ else
+ result = png_safe_execute(image, png_write_image_8bit, display);
+ display->local_row = NULL;
+
+ png_free(png_ptr, row);
+
+ /* Skip the 'write_end' on error: */
+ if (result == 0)
+ return 0;
+ }
+
+ /* Otherwise this is the case where the input is in a format currently
+ * supported by the rest of the libpng write code; call it directly.
+ */
+ else
+ {
+ png_const_bytep row = png_voidcast(png_const_bytep, display->first_row);
+ ptrdiff_t row_bytes = display->row_bytes;
+ png_uint_32 y = image->height;
+
+ for (; y > 0; --y)
+ {
+ png_write_row(png_ptr, row);
+ row += row_bytes;
+ }
+ }
+
+ png_write_end(png_ptr, info_ptr);
+ return 1;
+}
+
+
+static void (PNGCBAPI
+image_memory_write)(png_structp png_ptr, png_bytep/*const*/ data, size_t size)
+{
+ png_image_write_control *display = png_voidcast(png_image_write_control*,
+ png_ptr->io_ptr/*backdoor: png_get_io_ptr(png_ptr)*/);
+ png_alloc_size_t ob = display->output_bytes;
+
+ /* Check for overflow; this should never happen: */
+ if (size <= ((png_alloc_size_t)-1) - ob)
+ {
+ /* I don't think libpng ever does this, but just in case: */
+ if (size > 0)
+ {
+ if (display->memory_bytes >= ob+size) /* writing */
+ memcpy(display->memory+ob, data, size);
+
+ /* Always update the size: */
+ display->output_bytes = ob+size;
+ }
+ }
+
+ else
+ png_error(png_ptr, "png_image_write_to_memory: PNG too big");
+}
+
+static void (PNGCBAPI
+image_memory_flush)(png_structp png_ptr)
+{
+ PNG_UNUSED(png_ptr)
+}
+
+static int
+png_image_write_memory(png_voidp argument)
+{
+ png_image_write_control *display = png_voidcast(png_image_write_control*,
+ argument);
+
+ /* The rest of the memory-specific init and write_main in an error protected
+ * environment. This case needs to use callbacks for the write operations
+ * since libpng has no built in support for writing to memory.
+ */
+ png_set_write_fn(display->image->opaque->png_ptr, display/*io_ptr*/,
+ image_memory_write, image_memory_flush);
+
+ return png_image_write_main(display);
+}
+
+int PNGAPI
+png_image_write_to_memory(png_imagep image, void *memory,
+ png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8bit,
+ const void *buffer, png_int_32 row_stride, const void *colormap)
+{
+ /* Write the image to the given buffer, or count the bytes if it is NULL */
+ if (image != NULL && image->version == PNG_IMAGE_VERSION)
+ {
+ if (memory_bytes != NULL && buffer != NULL)
+ {
+ /* This is to give the caller an easier error detection in the NULL
+ * case and guard against uninitialized variable problems:
+ */
+ if (memory == NULL)
+ *memory_bytes = 0;
+
+ if (png_image_write_init(image) != 0)
+ {
+ png_image_write_control display;
+ int result;
+
+ memset(&display, 0, (sizeof display));
+ display.image = image;
+ display.buffer = buffer;
+ display.row_stride = row_stride;
+ display.colormap = colormap;
+ display.convert_to_8bit = convert_to_8bit;
+ display.memory = png_voidcast(png_bytep, memory);
+ display.memory_bytes = *memory_bytes;
+ display.output_bytes = 0;
+
+ result = png_safe_execute(image, png_image_write_memory, &display);
+ png_image_free(image);
+
+ /* write_memory returns true even if we ran out of buffer. */
+ if (result)
+ {
+ /* On out-of-buffer this function returns '0' but still updates
+ * memory_bytes:
+ */
+ if (memory != NULL && display.output_bytes > *memory_bytes)
+ result = 0;
+
+ *memory_bytes = display.output_bytes;
+ }
+
+ return result;
+ }
+
+ else
+ return 0;
+ }
+
+ else
+ return png_image_error(image,
+ "png_image_write_to_memory: invalid argument");
+ }
+
+ else if (image != NULL)
+ return png_image_error(image,
+ "png_image_write_to_memory: incorrect PNG_IMAGE_VERSION");
+
+ else
+ return 0;
+}
+
+#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
+int PNGAPI
+png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit,
+ const void *buffer, png_int_32 row_stride, const void *colormap)
+{
+ /* Write the image to the given FILE object. */
+ if (image != NULL && image->version == PNG_IMAGE_VERSION)
+ {
+ if (file != NULL && buffer != NULL)
+ {
+ if (png_image_write_init(image) != 0)
+ {
+ png_image_write_control display;
+ int result;
+
+ /* This is slightly evil, but png_init_io doesn't do anything other
+ * than this and we haven't changed the standard IO functions so
+ * this saves a 'safe' function.
+ */
+ image->opaque->png_ptr->io_ptr = file;
+
+ memset(&display, 0, (sizeof display));
+ display.image = image;
+ display.buffer = buffer;
+ display.row_stride = row_stride;
+ display.colormap = colormap;
+ display.convert_to_8bit = convert_to_8bit;
+
+ result = png_safe_execute(image, png_image_write_main, &display);
+ png_image_free(image);
+ return result;
+ }
+
+ else
+ return 0;
+ }
+
+ else
+ return png_image_error(image,
+ "png_image_write_to_stdio: invalid argument");
+ }
+
+ else if (image != NULL)
+ return png_image_error(image,
+ "png_image_write_to_stdio: incorrect PNG_IMAGE_VERSION");
+
+ else
+ return 0;
+}
+
+int PNGAPI
+png_image_write_to_file(png_imagep image, const char *file_name,
+ int convert_to_8bit, const void *buffer, png_int_32 row_stride,
+ const void *colormap)
+{
+ /* Write the image to the named file. */
+ if (image != NULL && image->version == PNG_IMAGE_VERSION)
+ {
+ if (file_name != NULL && buffer != NULL)
+ {
+ FILE *fp = fopen(file_name, "wb");
+
+ if (fp != NULL)
+ {
+ if (png_image_write_to_stdio(image, fp, convert_to_8bit, buffer,
+ row_stride, colormap) != 0)
+ {
+ int error; /* from fflush/fclose */
+
+ /* Make sure the file is flushed correctly. */
+ if (fflush(fp) == 0 && ferror(fp) == 0)
+ {
+ if (fclose(fp) == 0)
+ return 1;
+
+ error = errno; /* from fclose */
+ }
+
+ else
+ {
+ error = errno; /* from fflush or ferror */
+ (void)fclose(fp);
+ }
+
+ (void)remove(file_name);
+ /* The image has already been cleaned up; this is just used to
+ * set the error (because the original write succeeded).
+ */
+ return png_image_error(image, strerror(error));
+ }
+
+ else
+ {
+ /* Clean up: just the opened file. */
+ (void)fclose(fp);
+ (void)remove(file_name);
+ return 0;
+ }
+ }
+
+ else
+ return png_image_error(image, strerror(errno));
+ }
+
+ else
+ return png_image_error(image,
+ "png_image_write_to_file: invalid argument");
+ }
+
+ else if (image != NULL)
+ return png_image_error(image,
+ "png_image_write_to_file: incorrect PNG_IMAGE_VERSION");
+
+ else
+ return 0;
+}
+#endif /* SIMPLIFIED_WRITE_STDIO */
+#endif /* SIMPLIFIED_WRITE */
+#endif /* WRITE */
diff --git a/libs/imagequant/external/libpng/pngwtran.c b/libs/imagequant/external/libpng/pngwtran.c
new file mode 100644
index 00000000..a2084702
--- /dev/null
+++ b/libs/imagequant/external/libpng/pngwtran.c
@@ -0,0 +1,574 @@
+/* pngwtran.c - transforms the data in a row for PNG writers
+ *
+ * Copyright (c) 2018 Cosmin Truta
+ * Copyright (c) 1998-2002,2004,2006-2016,2018 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
+
+#ifdef PNG_WRITE_PACK_SUPPORTED
+/* Pack pixels into bytes. Pass the true bit depth in bit_depth. The
+ * row_info bit depth should be 8 (one pixel per byte). The channels
+ * should be 1 (this only happens on grayscale and paletted images).
+ */
+static void
+png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
+{
+ png_debug(1, "in png_do_pack");
+
+ if (row_info->bit_depth == 8 &&
+ row_info->channels == 1)
+ {
+ switch ((int)bit_depth)
+ {
+ case 1:
+ {
+ png_bytep sp, dp;
+ int mask, v;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ sp = row;
+ dp = row;
+ mask = 0x80;
+ v = 0;
+
+ for (i = 0; i < row_width; i++)
+ {
+ if (*sp != 0)
+ v |= mask;
+
+ sp++;
+
+ if (mask > 1)
+ mask >>= 1;
+
+ else
+ {
+ mask = 0x80;
+ *dp = (png_byte)v;
+ dp++;
+ v = 0;
+ }
+ }
+
+ if (mask != 0x80)
+ *dp = (png_byte)v;
+
+ break;
+ }
+
+ case 2:
+ {
+ png_bytep sp, dp;
+ unsigned int shift;
+ int v;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ sp = row;
+ dp = row;
+ shift = 6;
+ v = 0;
+
+ for (i = 0; i < row_width; i++)
+ {
+ png_byte value;
+
+ value = (png_byte)(*sp & 0x03);
+ v |= (value << shift);
+
+ if (shift == 0)
+ {
+ shift = 6;
+ *dp = (png_byte)v;
+ dp++;
+ v = 0;
+ }
+
+ else
+ shift -= 2;
+
+ sp++;
+ }
+
+ if (shift != 6)
+ *dp = (png_byte)v;
+
+ break;
+ }
+
+ case 4:
+ {
+ png_bytep sp, dp;
+ unsigned int shift;
+ int v;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ sp = row;
+ dp = row;
+ shift = 4;
+ v = 0;
+
+ for (i = 0; i < row_width; i++)
+ {
+ png_byte value;
+
+ value = (png_byte)(*sp & 0x0f);
+ v |= (value << shift);
+
+ if (shift == 0)
+ {
+ shift = 4;
+ *dp = (png_byte)v;
+ dp++;
+ v = 0;
+ }
+
+ else
+ shift -= 4;
+
+ sp++;
+ }
+
+ if (shift != 4)
+ *dp = (png_byte)v;
+
+ break;
+ }
+
+ default:
+ break;
+ }
+
+ row_info->bit_depth = (png_byte)bit_depth;
+ row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
+ row_info->width);
+ }
+}
+#endif
+
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+/* Shift pixel values to take advantage of whole range. Pass the
+ * true number of bits in bit_depth. The row should be packed
+ * according to row_info->bit_depth. Thus, if you had a row of
+ * bit depth 4, but the pixels only had values from 0 to 7, you
+ * would pass 3 as bit_depth, and this routine would translate the
+ * data to 0 to 15.
+ */
+static void
+png_do_shift(png_row_infop row_info, png_bytep row,
+ png_const_color_8p bit_depth)
+{
+ png_debug(1, "in png_do_shift");
+
+ if (row_info->color_type != PNG_COLOR_TYPE_PALETTE)
+ {
+ int shift_start[4], shift_dec[4];
+ unsigned int channels = 0;
+
+ if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
+ {
+ shift_start[channels] = row_info->bit_depth - bit_depth->red;
+ shift_dec[channels] = bit_depth->red;
+ channels++;
+
+ shift_start[channels] = row_info->bit_depth - bit_depth->green;
+ shift_dec[channels] = bit_depth->green;
+ channels++;
+
+ shift_start[channels] = row_info->bit_depth - bit_depth->blue;
+ shift_dec[channels] = bit_depth->blue;
+ channels++;
+ }
+
+ else
+ {
+ shift_start[channels] = row_info->bit_depth - bit_depth->gray;
+ shift_dec[channels] = bit_depth->gray;
+ channels++;
+ }
+
+ if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+ {
+ shift_start[channels] = row_info->bit_depth - bit_depth->alpha;
+ shift_dec[channels] = bit_depth->alpha;
+ channels++;
+ }
+
+ /* With low row depths, could only be grayscale, so one channel */
+ if (row_info->bit_depth < 8)
+ {
+ png_bytep bp = row;
+ size_t i;
+ unsigned int mask;
+ size_t row_bytes = row_info->rowbytes;
+
+ if (bit_depth->gray == 1 && row_info->bit_depth == 2)
+ mask = 0x55;
+
+ else if (row_info->bit_depth == 4 && bit_depth->gray == 3)
+ mask = 0x11;
+
+ else
+ mask = 0xff;
+
+ for (i = 0; i < row_bytes; i++, bp++)
+ {
+ int j;
+ unsigned int v, out;
+
+ v = *bp;
+ out = 0;
+
+ for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0])
+ {
+ if (j > 0)
+ out |= v << j;
+
+ else
+ out |= (v >> (-j)) & mask;
+ }
+
+ *bp = (png_byte)(out & 0xff);
+ }
+ }
+
+ else if (row_info->bit_depth == 8)
+ {
+ png_bytep bp = row;
+ png_uint_32 i;
+ png_uint_32 istop = channels * row_info->width;
+
+ for (i = 0; i < istop; i++, bp++)
+ {
+ unsigned int c = i%channels;
+ int j;
+ unsigned int v, out;
+
+ v = *bp;
+ out = 0;
+
+ for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
+ {
+ if (j > 0)
+ out |= v << j;
+
+ else
+ out |= v >> (-j);
+ }
+
+ *bp = (png_byte)(out & 0xff);
+ }
+ }
+
+ else
+ {
+ png_bytep bp;
+ png_uint_32 i;
+ png_uint_32 istop = channels * row_info->width;
+
+ for (bp = row, i = 0; i < istop; i++)
+ {
+ unsigned int c = i%channels;
+ int j;
+ unsigned int value, v;
+
+ v = png_get_uint_16(bp);
+ value = 0;
+
+ for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
+ {
+ if (j > 0)
+ value |= v << j;
+
+ else
+ value |= v >> (-j);
+ }
+ *bp++ = (png_byte)((value >> 8) & 0xff);
+ *bp++ = (png_byte)(value & 0xff);
+ }
+ }
+ }
+}
+#endif
+
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+static void
+png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_write_swap_alpha");
+
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ /* This converts from ARGB to RGBA */
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ png_byte save = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = save;
+ }
+ }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ else
+ {
+ /* This converts from AARRGGBB to RRGGBBAA */
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ png_byte save[2];
+ save[0] = *(sp++);
+ save[1] = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = save[0];
+ *(dp++) = save[1];
+ }
+ }
+#endif /* WRITE_16BIT */
+ }
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ /* This converts from AG to GA */
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ png_byte save = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = save;
+ }
+ }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ else
+ {
+ /* This converts from AAGG to GGAA */
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ png_byte save[2];
+ save[0] = *(sp++);
+ save[1] = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = save[0];
+ *(dp++) = save[1];
+ }
+ }
+#endif /* WRITE_16BIT */
+ }
+ }
+}
+#endif
+
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+static void
+png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_write_invert_alpha");
+
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ /* This inverts the alpha channel in RGBA */
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ /* Does nothing
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ */
+ sp+=3; dp = sp;
+ *dp = (png_byte)(255 - *(sp++));
+ }
+ }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ else
+ {
+ /* This inverts the alpha channel in RRGGBBAA */
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ /* Does nothing
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ */
+ sp+=6; dp = sp;
+ *(dp++) = (png_byte)(255 - *(sp++));
+ *dp = (png_byte)(255 - *(sp++));
+ }
+ }
+#endif /* WRITE_16BIT */
+ }
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ /* This inverts the alpha channel in GA */
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ *(dp++) = *(sp++);
+ *(dp++) = (png_byte)(255 - *(sp++));
+ }
+ }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ else
+ {
+ /* This inverts the alpha channel in GGAA */
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ for (i = 0, sp = dp = row; i < row_width; i++)
+ {
+ /* Does nothing
+ *(dp++) = *(sp++);
+ *(dp++) = *(sp++);
+ */
+ sp+=2; dp = sp;
+ *(dp++) = (png_byte)(255 - *(sp++));
+ *dp = (png_byte)(255 - *(sp++));
+ }
+ }
+#endif /* WRITE_16BIT */
+ }
+ }
+}
+#endif
+
+/* Transform the data according to the user's wishes. The order of
+ * transformations is significant.
+ */
+void /* PRIVATE */
+png_do_write_transformations(png_structrp png_ptr, png_row_infop row_info)
+{
+ png_debug(1, "in png_do_write_transformations");
+
+ if (png_ptr == NULL)
+ return;
+
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+ if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
+ if (png_ptr->write_user_transform_fn != NULL)
+ (*(png_ptr->write_user_transform_fn)) /* User write transform
+ function */
+ (png_ptr, /* png_ptr */
+ row_info, /* row_info: */
+ /* png_uint_32 width; width of row */
+ /* size_t rowbytes; number of bytes in row */
+ /* png_byte color_type; color type of pixels */
+ /* png_byte bit_depth; bit depth of samples */
+ /* png_byte channels; number of channels (1-4) */
+ /* png_byte pixel_depth; bits per pixel (depth*channels) */
+ png_ptr->row_buf + 1); /* start of pixel data for row */
+#endif
+
+#ifdef PNG_WRITE_FILLER_SUPPORTED
+ if ((png_ptr->transformations & PNG_FILLER) != 0)
+ png_do_strip_channel(row_info, png_ptr->row_buf + 1,
+ !(png_ptr->flags & PNG_FLAG_FILLER_AFTER));
+#endif
+
+#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
+ if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
+ png_do_packswap(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_WRITE_PACK_SUPPORTED
+ if ((png_ptr->transformations & PNG_PACK) != 0)
+ png_do_pack(row_info, png_ptr->row_buf + 1,
+ (png_uint_32)png_ptr->bit_depth);
+#endif
+
+#ifdef PNG_WRITE_SWAP_SUPPORTED
+# ifdef PNG_16BIT_SUPPORTED
+ if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
+ png_do_swap(row_info, png_ptr->row_buf + 1);
+# endif
+#endif
+
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+ if ((png_ptr->transformations & PNG_SHIFT) != 0)
+ png_do_shift(row_info, png_ptr->row_buf + 1,
+ &(png_ptr->shift));
+#endif
+
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+ if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0)
+ png_do_write_swap_alpha(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+ if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0)
+ png_do_write_invert_alpha(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_WRITE_BGR_SUPPORTED
+ if ((png_ptr->transformations & PNG_BGR) != 0)
+ png_do_bgr(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_WRITE_INVERT_SUPPORTED
+ if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
+ png_do_invert(row_info, png_ptr->row_buf + 1);
+#endif
+}
+#endif /* WRITE_TRANSFORMS */
+#endif /* WRITE */
diff --git a/libs/imagequant/external/libpng/pngwutil.c b/libs/imagequant/external/libpng/pngwutil.c
new file mode 100644
index 00000000..863ffe8c
--- /dev/null
+++ b/libs/imagequant/external/libpng/pngwutil.c
@@ -0,0 +1,2825 @@
+/* pngwutil.c - utilities to write a PNG file
+ *
+ * Copyright (c) 2018-2025 Cosmin Truta
+ * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file contains routines that are only called from within
+ * libpng itself during the course of writing an image.
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_WRITE_SUPPORTED
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+/* Arrays to facilitate interlacing - use pass (0 - 6) as index. */
+
+/* Start of interlace block */
+static const png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+/* Offset to next interlace block */
+static const png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+/* Start of interlace block in the y direction */
+static const png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+/* Offset to next interlace block in the y direction */
+static const png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+
+/* TODO: Move these arrays to a common utility module to avoid duplication. */
+#endif
+
+#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
+/* Place a 32-bit number into a buffer in PNG byte order. We work
+ * with unsigned numbers for convenience, although one supported
+ * ancillary chunk uses signed (two's complement) numbers.
+ */
+void PNGAPI
+png_save_uint_32(png_bytep buf, png_uint_32 i)
+{
+ buf[0] = (png_byte)((i >> 24) & 0xffU);
+ buf[1] = (png_byte)((i >> 16) & 0xffU);
+ buf[2] = (png_byte)((i >> 8) & 0xffU);
+ buf[3] = (png_byte)( i & 0xffU);
+}
+
+/* Place a 16-bit number into a buffer in PNG byte order.
+ * The parameter is declared unsigned int, not png_uint_16,
+ * just to avoid potential problems on pre-ANSI C compilers.
+ */
+void PNGAPI
+png_save_uint_16(png_bytep buf, unsigned int i)
+{
+ buf[0] = (png_byte)((i >> 8) & 0xffU);
+ buf[1] = (png_byte)( i & 0xffU);
+}
+#endif
+
+/* Simple function to write the signature. If we have already written
+ * the magic bytes of the signature, or more likely, the PNG stream is
+ * being embedded into another stream and doesn't need its own signature,
+ * we should call png_set_sig_bytes() to tell libpng how many of the
+ * bytes have already been written.
+ */
+void PNGAPI
+png_write_sig(png_structrp png_ptr)
+{
+ png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ /* Inform the I/O callback that the signature is being written */
+ png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE;
+#endif
+
+ /* Write the rest of the 8 byte signature */
+ png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
+ (size_t)(8 - png_ptr->sig_bytes));
+
+ if (png_ptr->sig_bytes < 3)
+ png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
+}
+
+/* Write the start of a PNG chunk. The type is the chunk type.
+ * The total_length is the sum of the lengths of all the data you will be
+ * passing in png_write_chunk_data().
+ */
+static void
+png_write_chunk_header(png_structrp png_ptr, png_uint_32 chunk_name,
+ png_uint_32 length)
+{
+ png_byte buf[8];
+
+#if defined(PNG_DEBUG) && (PNG_DEBUG > 0)
+ PNG_CSTRING_FROM_CHUNK(buf, chunk_name);
+ png_debug2(0, "Writing %s chunk, length = %lu", buf, (unsigned long)length);
+#endif
+
+ if (png_ptr == NULL)
+ return;
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ /* Inform the I/O callback that the chunk header is being written.
+ * PNG_IO_CHUNK_HDR requires a single I/O call.
+ */
+ png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR;
+#endif
+
+ /* Write the length and the chunk name */
+ png_save_uint_32(buf, length);
+ png_save_uint_32(buf + 4, chunk_name);
+ png_write_data(png_ptr, buf, 8);
+
+ /* Put the chunk name into png_ptr->chunk_name */
+ png_ptr->chunk_name = chunk_name;
+
+ /* Reset the crc and run it over the chunk name */
+ png_reset_crc(png_ptr);
+
+ png_calculate_crc(png_ptr, buf + 4, 4);
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ /* Inform the I/O callback that chunk data will (possibly) be written.
+ * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls.
+ */
+ png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA;
+#endif
+}
+
+void PNGAPI
+png_write_chunk_start(png_structrp png_ptr, png_const_bytep chunk_string,
+ png_uint_32 length)
+{
+ png_write_chunk_header(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), length);
+}
+
+/* Write the data of a PNG chunk started with png_write_chunk_header().
+ * Note that multiple calls to this function are allowed, and that the
+ * sum of the lengths from these calls *must* add up to the total_length
+ * given to png_write_chunk_header().
+ */
+void PNGAPI
+png_write_chunk_data(png_structrp png_ptr, png_const_bytep data, size_t length)
+{
+ /* Write the data, and run the CRC over it */
+ if (png_ptr == NULL)
+ return;
+
+ if (data != NULL && length > 0)
+ {
+ png_write_data(png_ptr, data, length);
+
+ /* Update the CRC after writing the data,
+ * in case the user I/O routine alters it.
+ */
+ png_calculate_crc(png_ptr, data, length);
+ }
+}
+
+/* Finish a chunk started with png_write_chunk_header(). */
+void PNGAPI
+png_write_chunk_end(png_structrp png_ptr)
+{
+ png_byte buf[4];
+
+ if (png_ptr == NULL) return;
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ /* Inform the I/O callback that the chunk CRC is being written.
+ * PNG_IO_CHUNK_CRC requires a single I/O function call.
+ */
+ png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC;
+#endif
+
+ /* Write the crc in a single operation */
+ png_save_uint_32(buf, png_ptr->crc);
+
+ png_write_data(png_ptr, buf, 4);
+}
+
+/* Write a PNG chunk all at once. The type is an array of ASCII characters
+ * representing the chunk name. The array must be at least 4 bytes in
+ * length, and does not need to be null terminated. To be safe, pass the
+ * pre-defined chunk names here, and if you need a new one, define it
+ * where the others are defined. The length is the length of the data.
+ * All the data must be present. If that is not possible, use the
+ * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()
+ * functions instead.
+ */
+static void
+png_write_complete_chunk(png_structrp png_ptr, png_uint_32 chunk_name,
+ png_const_bytep data, size_t length)
+{
+ if (png_ptr == NULL)
+ return;
+
+ /* On 64-bit architectures 'length' may not fit in a png_uint_32. */
+ if (length > PNG_UINT_31_MAX)
+ png_error(png_ptr, "length exceeds PNG maximum");
+
+ png_write_chunk_header(png_ptr, chunk_name, (png_uint_32)length);
+ png_write_chunk_data(png_ptr, data, length);
+ png_write_chunk_end(png_ptr);
+}
+
+/* This is the API that calls the internal function above. */
+void PNGAPI
+png_write_chunk(png_structrp png_ptr, png_const_bytep chunk_string,
+ png_const_bytep data, size_t length)
+{
+ png_write_complete_chunk(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), data,
+ length);
+}
+
+/* This is used below to find the size of an image to pass to png_deflate_claim,
+ * so it only needs to be accurate if the size is less than 16384 bytes (the
+ * point at which a lower LZ window size can be used.)
+ */
+static png_alloc_size_t
+png_image_size(png_structrp png_ptr)
+{
+ /* Only return sizes up to the maximum of a png_uint_32; do this by limiting
+ * the width and height used to 15 bits.
+ */
+ png_uint_32 h = png_ptr->height;
+
+ if (png_ptr->rowbytes < 32768 && h < 32768)
+ {
+ if (png_ptr->interlaced != 0)
+ {
+ /* Interlacing makes the image larger because of the replication of
+ * both the filter byte and the padding to a byte boundary.
+ */
+ png_uint_32 w = png_ptr->width;
+ unsigned int pd = png_ptr->pixel_depth;
+ png_alloc_size_t cb_base;
+ int pass;
+
+ for (cb_base=0, pass=0; pass<=6; ++pass)
+ {
+ png_uint_32 pw = PNG_PASS_COLS(w, pass);
+
+ if (pw > 0)
+ cb_base += (PNG_ROWBYTES(pd, pw)+1) * PNG_PASS_ROWS(h, pass);
+ }
+
+ return cb_base;
+ }
+
+ else
+ return (png_ptr->rowbytes+1) * h;
+ }
+
+ else
+ return 0xffffffffU;
+}
+
+#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+ /* This is the code to hack the first two bytes of the deflate stream (the
+ * deflate header) to correct the windowBits value to match the actual data
+ * size. Note that the second argument is the *uncompressed* size but the
+ * first argument is the *compressed* data (and it must be deflate
+ * compressed.)
+ */
+static void
+optimize_cmf(png_bytep data, png_alloc_size_t data_size)
+{
+ /* Optimize the CMF field in the zlib stream. The resultant zlib stream is
+ * still compliant to the stream specification.
+ */
+ if (data_size <= 16384) /* else windowBits must be 15 */
+ {
+ unsigned int z_cmf = data[0]; /* zlib compression method and flags */
+
+ if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
+ {
+ unsigned int z_cinfo;
+ unsigned int half_z_window_size;
+
+ z_cinfo = z_cmf >> 4;
+ half_z_window_size = 1U << (z_cinfo + 7);
+
+ if (data_size <= half_z_window_size) /* else no change */
+ {
+ unsigned int tmp;
+
+ do
+ {
+ half_z_window_size >>= 1;
+ --z_cinfo;
+ }
+ while (z_cinfo > 0 && data_size <= half_z_window_size);
+
+ z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
+
+ data[0] = (png_byte)z_cmf;
+ tmp = data[1] & 0xe0;
+ tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f;
+ data[1] = (png_byte)tmp;
+ }
+ }
+ }
+}
+#endif /* WRITE_OPTIMIZE_CMF */
+
+/* Initialize the compressor for the appropriate type of compression. */
+static int
+png_deflate_claim(png_structrp png_ptr, png_uint_32 owner,
+ png_alloc_size_t data_size)
+{
+ if (png_ptr->zowner != 0)
+ {
+#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED)
+ char msg[64];
+
+ PNG_STRING_FROM_CHUNK(msg, owner);
+ msg[4] = ':';
+ msg[5] = ' ';
+ PNG_STRING_FROM_CHUNK(msg+6, png_ptr->zowner);
+ /* So the message that results is " using zstream"; this is an
+ * internal error, but is very useful for debugging. i18n requirements
+ * are minimal.
+ */
+ (void)png_safecat(msg, (sizeof msg), 10, " using zstream");
+#endif
+#if PNG_RELEASE_BUILD
+ png_warning(png_ptr, msg);
+
+ /* Attempt sane error recovery */
+ if (png_ptr->zowner == png_IDAT) /* don't steal from IDAT */
+ {
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("in use by IDAT");
+ return Z_STREAM_ERROR;
+ }
+
+ png_ptr->zowner = 0;
+#else
+ png_error(png_ptr, msg);
+#endif
+ }
+
+ {
+ int level = png_ptr->zlib_level;
+ int method = png_ptr->zlib_method;
+ int windowBits = png_ptr->zlib_window_bits;
+ int memLevel = png_ptr->zlib_mem_level;
+ int strategy; /* set below */
+ int ret; /* zlib return code */
+
+ if (owner == png_IDAT)
+ {
+ if ((png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY) != 0)
+ strategy = png_ptr->zlib_strategy;
+
+ else if (png_ptr->do_filter != PNG_FILTER_NONE)
+ strategy = PNG_Z_DEFAULT_STRATEGY;
+
+ else
+ strategy = PNG_Z_DEFAULT_NOFILTER_STRATEGY;
+ }
+
+ else
+ {
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+ level = png_ptr->zlib_text_level;
+ method = png_ptr->zlib_text_method;
+ windowBits = png_ptr->zlib_text_window_bits;
+ memLevel = png_ptr->zlib_text_mem_level;
+ strategy = png_ptr->zlib_text_strategy;
+#else
+ /* If customization is not supported the values all come from the
+ * IDAT values except for the strategy, which is fixed to the
+ * default. (This is the pre-1.6.0 behavior too, although it was
+ * implemented in a very different way.)
+ */
+ strategy = Z_DEFAULT_STRATEGY;
+#endif
+ }
+
+ /* Adjust 'windowBits' down if larger than 'data_size'; to stop this
+ * happening just pass 32768 as the data_size parameter. Notice that zlib
+ * requires an extra 262 bytes in the window in addition to the data to be
+ * able to see the whole of the data, so if data_size+262 takes us to the
+ * next windowBits size we need to fix up the value later. (Because even
+ * though deflate needs the extra window, inflate does not!)
+ */
+ if (data_size <= 16384)
+ {
+ /* IMPLEMENTATION NOTE: this 'half_window_size' stuff is only here to
+ * work round a Microsoft Visual C misbehavior which, contrary to C-90,
+ * widens the result of the following shift to 64-bits if (and,
+ * apparently, only if) it is used in a test.
+ */
+ unsigned int half_window_size = 1U << (windowBits-1);
+
+ while (data_size + 262 <= half_window_size)
+ {
+ half_window_size >>= 1;
+ --windowBits;
+ }
+ }
+
+ /* Check against the previous initialized values, if any. */
+ if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0 &&
+ (png_ptr->zlib_set_level != level ||
+ png_ptr->zlib_set_method != method ||
+ png_ptr->zlib_set_window_bits != windowBits ||
+ png_ptr->zlib_set_mem_level != memLevel ||
+ png_ptr->zlib_set_strategy != strategy))
+ {
+ if (deflateEnd(&png_ptr->zstream) != Z_OK)
+ png_warning(png_ptr, "deflateEnd failed (ignored)");
+
+ png_ptr->flags &= ~PNG_FLAG_ZSTREAM_INITIALIZED;
+ }
+
+ /* For safety clear out the input and output pointers (currently zlib
+ * doesn't use them on Init, but it might in the future).
+ */
+ png_ptr->zstream.next_in = NULL;
+ png_ptr->zstream.avail_in = 0;
+ png_ptr->zstream.next_out = NULL;
+ png_ptr->zstream.avail_out = 0;
+
+ /* Now initialize if required, setting the new parameters, otherwise just
+ * do a simple reset to the previous parameters.
+ */
+ if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0)
+ ret = deflateReset(&png_ptr->zstream);
+
+ else
+ {
+ ret = deflateInit2(&png_ptr->zstream, level, method, windowBits,
+ memLevel, strategy);
+
+ if (ret == Z_OK)
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED;
+ }
+
+ /* The return code is from either deflateReset or deflateInit2; they have
+ * pretty much the same set of error codes.
+ */
+ if (ret == Z_OK)
+ png_ptr->zowner = owner;
+
+ else
+ png_zstream_error(png_ptr, ret);
+
+ return ret;
+ }
+}
+
+/* Clean up (or trim) a linked list of compression buffers. */
+void /* PRIVATE */
+png_free_buffer_list(png_structrp png_ptr, png_compression_bufferp *listp)
+{
+ png_compression_bufferp list = *listp;
+
+ if (list != NULL)
+ {
+ *listp = NULL;
+
+ do
+ {
+ png_compression_bufferp next = list->next;
+
+ png_free(png_ptr, list);
+ list = next;
+ }
+ while (list != NULL);
+ }
+}
+
+#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+/* This pair of functions encapsulates the operation of (a) compressing a
+ * text string, and (b) issuing it later as a series of chunk data writes.
+ * The compression_state structure is shared context for these functions
+ * set up by the caller to allow access to the relevant local variables.
+ *
+ * compression_buffer (new in 1.6.0) is just a linked list of zbuffer_size
+ * temporary buffers. From 1.6.0 it is retained in png_struct so that it will
+ * be correctly freed in the event of a write error (previous implementations
+ * just leaked memory.)
+ */
+typedef struct
+{
+ png_const_bytep input; /* The uncompressed input data */
+ png_alloc_size_t input_len; /* Its length */
+ png_uint_32 output_len; /* Final compressed length */
+ png_byte output[1024]; /* First block of output */
+} compression_state;
+
+static void
+png_text_compress_init(compression_state *comp, png_const_bytep input,
+ png_alloc_size_t input_len)
+{
+ comp->input = input;
+ comp->input_len = input_len;
+ comp->output_len = 0;
+}
+
+/* Compress the data in the compression state input */
+static int
+png_text_compress(png_structrp png_ptr, png_uint_32 chunk_name,
+ compression_state *comp, png_uint_32 prefix_len)
+{
+ int ret;
+
+ /* To find the length of the output it is necessary to first compress the
+ * input. The result is buffered rather than using the two-pass algorithm
+ * that is used on the inflate side; deflate is assumed to be slower and a
+ * PNG writer is assumed to have more memory available than a PNG reader.
+ *
+ * IMPLEMENTATION NOTE: the zlib API deflateBound() can be used to find an
+ * upper limit on the output size, but it is always bigger than the input
+ * size so it is likely to be more efficient to use this linked-list
+ * approach.
+ */
+ ret = png_deflate_claim(png_ptr, chunk_name, comp->input_len);
+
+ if (ret != Z_OK)
+ return ret;
+
+ /* Set up the compression buffers, we need a loop here to avoid overflowing a
+ * uInt. Use ZLIB_IO_MAX to limit the input. The output is always limited
+ * by the output buffer size, so there is no need to check that. Since this
+ * is ANSI-C we know that an 'int', hence a uInt, is always at least 16 bits
+ * in size.
+ */
+ {
+ png_compression_bufferp *end = &png_ptr->zbuffer_list;
+ png_alloc_size_t input_len = comp->input_len; /* may be zero! */
+ png_uint_32 output_len;
+
+ /* zlib updates these for us: */
+ png_ptr->zstream.next_in = PNGZ_INPUT_CAST(comp->input);
+ png_ptr->zstream.avail_in = 0; /* Set below */
+ png_ptr->zstream.next_out = comp->output;
+ png_ptr->zstream.avail_out = (sizeof comp->output);
+
+ output_len = png_ptr->zstream.avail_out;
+
+ do
+ {
+ uInt avail_in = ZLIB_IO_MAX;
+
+ if (avail_in > input_len)
+ avail_in = (uInt)input_len;
+
+ input_len -= avail_in;
+
+ png_ptr->zstream.avail_in = avail_in;
+
+ if (png_ptr->zstream.avail_out == 0)
+ {
+ png_compression_buffer *next;
+
+ /* Chunk data is limited to 2^31 bytes in length, so the prefix
+ * length must be counted here.
+ */
+ if (output_len + prefix_len > PNG_UINT_31_MAX)
+ {
+ ret = Z_MEM_ERROR;
+ break;
+ }
+
+ /* Need a new (malloc'ed) buffer, but there may be one present
+ * already.
+ */
+ next = *end;
+ if (next == NULL)
+ {
+ next = png_voidcast(png_compression_bufferp, png_malloc_base
+ (png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr)));
+
+ if (next == NULL)
+ {
+ ret = Z_MEM_ERROR;
+ break;
+ }
+
+ /* Link in this buffer (so that it will be freed later) */
+ next->next = NULL;
+ *end = next;
+ }
+
+ png_ptr->zstream.next_out = next->output;
+ png_ptr->zstream.avail_out = png_ptr->zbuffer_size;
+ output_len += png_ptr->zstream.avail_out;
+
+ /* Move 'end' to the next buffer pointer. */
+ end = &next->next;
+ }
+
+ /* Compress the data */
+ ret = deflate(&png_ptr->zstream,
+ input_len > 0 ? Z_NO_FLUSH : Z_FINISH);
+
+ /* Claw back input data that was not consumed (because avail_in is
+ * reset above every time round the loop).
+ */
+ input_len += png_ptr->zstream.avail_in;
+ png_ptr->zstream.avail_in = 0; /* safety */
+ }
+ while (ret == Z_OK);
+
+ /* There may be some space left in the last output buffer. This needs to
+ * be subtracted from output_len.
+ */
+ output_len -= png_ptr->zstream.avail_out;
+ png_ptr->zstream.avail_out = 0; /* safety */
+ comp->output_len = output_len;
+
+ /* Now double check the output length, put in a custom message if it is
+ * too long. Otherwise ensure the z_stream::msg pointer is set to
+ * something.
+ */
+ if (output_len + prefix_len >= PNG_UINT_31_MAX)
+ {
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("compressed data too long");
+ ret = Z_MEM_ERROR;
+ }
+
+ else
+ png_zstream_error(png_ptr, ret);
+
+ /* Reset zlib for another zTXt/iTXt or image data */
+ png_ptr->zowner = 0;
+
+ /* The only success case is Z_STREAM_END, input_len must be 0; if not this
+ * is an internal error.
+ */
+ if (ret == Z_STREAM_END && input_len == 0)
+ {
+#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+ /* Fix up the deflate header, if required */
+ optimize_cmf(comp->output, comp->input_len);
+#endif
+ /* But Z_OK is returned, not Z_STREAM_END; this allows the claim
+ * function above to return Z_STREAM_END on an error (though it never
+ * does in the current versions of zlib.)
+ */
+ return Z_OK;
+ }
+
+ else
+ return ret;
+ }
+}
+
+/* Ship the compressed text out via chunk writes */
+static void
+png_write_compressed_data_out(png_structrp png_ptr, compression_state *comp)
+{
+ png_uint_32 output_len = comp->output_len;
+ png_const_bytep output = comp->output;
+ png_uint_32 avail = (sizeof comp->output);
+ png_compression_buffer *next = png_ptr->zbuffer_list;
+
+ for (;;)
+ {
+ if (avail > output_len)
+ avail = output_len;
+
+ png_write_chunk_data(png_ptr, output, avail);
+
+ output_len -= avail;
+
+ if (output_len == 0 || next == NULL)
+ break;
+
+ avail = png_ptr->zbuffer_size;
+ output = next->output;
+ next = next->next;
+ }
+
+ /* This is an internal error; 'next' must have been NULL! */
+ if (output_len > 0)
+ png_error(png_ptr, "error writing ancillary chunked compressed data");
+}
+#endif /* WRITE_COMPRESSED_TEXT */
+
+/* Write the IHDR chunk, and update the png_struct with the necessary
+ * information. Note that the rest of this code depends upon this
+ * information being correct.
+ */
+void /* PRIVATE */
+png_write_IHDR(png_structrp png_ptr, png_uint_32 width, png_uint_32 height,
+ int bit_depth, int color_type, int compression_type, int filter_type,
+ int interlace_type)
+{
+ png_byte buf[13]; /* Buffer to store the IHDR info */
+ int is_invalid_depth;
+
+ png_debug(1, "in png_write_IHDR");
+
+ /* Check that we have valid input data from the application info */
+ switch (color_type)
+ {
+ case PNG_COLOR_TYPE_GRAY:
+ switch (bit_depth)
+ {
+ case 1:
+ case 2:
+ case 4:
+ case 8:
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ case 16:
+#endif
+ png_ptr->channels = 1; break;
+
+ default:
+ png_error(png_ptr,
+ "Invalid bit depth for grayscale image");
+ }
+ break;
+
+ case PNG_COLOR_TYPE_RGB:
+ is_invalid_depth = (bit_depth != 8);
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ is_invalid_depth = (is_invalid_depth && bit_depth != 16);
+#endif
+ if (is_invalid_depth)
+ png_error(png_ptr, "Invalid bit depth for RGB image");
+
+ png_ptr->channels = 3;
+ break;
+
+ case PNG_COLOR_TYPE_PALETTE:
+ switch (bit_depth)
+ {
+ case 1:
+ case 2:
+ case 4:
+ case 8:
+ png_ptr->channels = 1;
+ break;
+
+ default:
+ png_error(png_ptr, "Invalid bit depth for paletted image");
+ }
+ break;
+
+ case PNG_COLOR_TYPE_GRAY_ALPHA:
+ is_invalid_depth = (bit_depth != 8);
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ is_invalid_depth = (is_invalid_depth && bit_depth != 16);
+#endif
+ if (is_invalid_depth)
+ png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
+
+ png_ptr->channels = 2;
+ break;
+
+ case PNG_COLOR_TYPE_RGB_ALPHA:
+ is_invalid_depth = (bit_depth != 8);
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ is_invalid_depth = (is_invalid_depth && bit_depth != 16);
+#endif
+ if (is_invalid_depth)
+ png_error(png_ptr, "Invalid bit depth for RGBA image");
+
+ png_ptr->channels = 4;
+ break;
+
+ default:
+ png_error(png_ptr, "Invalid image color type specified");
+ }
+
+ if (compression_type != PNG_COMPRESSION_TYPE_BASE)
+ {
+ png_warning(png_ptr, "Invalid compression type specified");
+ compression_type = PNG_COMPRESSION_TYPE_BASE;
+ }
+
+ /* Write filter_method 64 (intrapixel differencing) only if
+ * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
+ * 2. Libpng did not write a PNG signature (this filter_method is only
+ * used in PNG datastreams that are embedded in MNG datastreams) and
+ * 3. The application called png_permit_mng_features with a mask that
+ * included PNG_FLAG_MNG_FILTER_64 and
+ * 4. The filter_method is 64 and
+ * 5. The color_type is RGB or RGBA
+ */
+ if (
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
+ ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) == 0) &&
+ (color_type == PNG_COLOR_TYPE_RGB ||
+ color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&
+ (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&
+#endif
+ filter_type != PNG_FILTER_TYPE_BASE)
+ {
+ png_warning(png_ptr, "Invalid filter type specified");
+ filter_type = PNG_FILTER_TYPE_BASE;
+ }
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ if (interlace_type != PNG_INTERLACE_NONE &&
+ interlace_type != PNG_INTERLACE_ADAM7)
+ {
+ png_warning(png_ptr, "Invalid interlace type specified");
+ interlace_type = PNG_INTERLACE_ADAM7;
+ }
+#else
+ interlace_type=PNG_INTERLACE_NONE;
+#endif
+
+ /* Save the relevant information */
+ png_ptr->bit_depth = (png_byte)bit_depth;
+ png_ptr->color_type = (png_byte)color_type;
+ png_ptr->interlaced = (png_byte)interlace_type;
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ png_ptr->filter_type = (png_byte)filter_type;
+#endif
+ png_ptr->compression_type = (png_byte)compression_type;
+ png_ptr->width = width;
+ png_ptr->height = height;
+
+ png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels);
+ png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);
+ /* Set the usr info, so any transformations can modify it */
+ png_ptr->usr_width = png_ptr->width;
+ png_ptr->usr_bit_depth = png_ptr->bit_depth;
+ png_ptr->usr_channels = png_ptr->channels;
+
+ /* Pack the header information into the buffer */
+ png_save_uint_32(buf, width);
+ png_save_uint_32(buf + 4, height);
+ buf[8] = (png_byte)bit_depth;
+ buf[9] = (png_byte)color_type;
+ buf[10] = (png_byte)compression_type;
+ buf[11] = (png_byte)filter_type;
+ buf[12] = (png_byte)interlace_type;
+
+ /* Write the chunk */
+ png_write_complete_chunk(png_ptr, png_IHDR, buf, 13);
+
+ if ((png_ptr->do_filter) == PNG_NO_FILTERS)
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
+ png_ptr->bit_depth < 8)
+ png_ptr->do_filter = PNG_FILTER_NONE;
+
+ else
+ png_ptr->do_filter = PNG_ALL_FILTERS;
+ }
+
+ png_ptr->mode = PNG_HAVE_IHDR; /* not READY_FOR_ZTXT */
+}
+
+/* Write the palette. We are careful not to trust png_color to be in the
+ * correct order for PNG, so people can redefine it to any convenient
+ * structure.
+ */
+void /* PRIVATE */
+png_write_PLTE(png_structrp png_ptr, png_const_colorp palette,
+ png_uint_32 num_pal)
+{
+ png_uint_32 max_palette_length, i;
+ png_const_colorp pal_ptr;
+ png_byte buf[3];
+
+ png_debug(1, "in png_write_PLTE");
+
+ max_palette_length = (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ?
+ (1 << png_ptr->bit_depth) : PNG_MAX_PALETTE_LENGTH;
+
+ if ((
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0 &&
+#endif
+ num_pal == 0) || num_pal > max_palette_length)
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ png_error(png_ptr, "Invalid number of colors in palette");
+ }
+
+ else
+ {
+ png_warning(png_ptr, "Invalid number of colors in palette");
+ return;
+ }
+ }
+
+ if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0)
+ {
+ png_warning(png_ptr,
+ "Ignoring request to write a PLTE chunk in grayscale PNG");
+
+ return;
+ }
+
+ png_ptr->num_palette = (png_uint_16)num_pal;
+ png_debug1(3, "num_palette = %d", png_ptr->num_palette);
+
+ png_write_chunk_header(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3));
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+
+ for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
+ {
+ buf[0] = pal_ptr->red;
+ buf[1] = pal_ptr->green;
+ buf[2] = pal_ptr->blue;
+ png_write_chunk_data(png_ptr, buf, 3);
+ }
+
+#else
+ /* This is a little slower but some buggy compilers need to do this
+ * instead
+ */
+ pal_ptr=palette;
+
+ for (i = 0; i < num_pal; i++)
+ {
+ buf[0] = pal_ptr[i].red;
+ buf[1] = pal_ptr[i].green;
+ buf[2] = pal_ptr[i].blue;
+ png_write_chunk_data(png_ptr, buf, 3);
+ }
+
+#endif
+ png_write_chunk_end(png_ptr);
+ png_ptr->mode |= PNG_HAVE_PLTE;
+}
+
+/* This is similar to png_text_compress, above, except that it does not require
+ * all of the data at once and, instead of buffering the compressed result,
+ * writes it as IDAT chunks. Unlike png_text_compress it *can* png_error out
+ * because it calls the write interface. As a result it does its own error
+ * reporting and does not return an error code. In the event of error it will
+ * just call png_error. The input data length may exceed 32-bits. The 'flush'
+ * parameter is exactly the same as that to deflate, with the following
+ * meanings:
+ *
+ * Z_NO_FLUSH: normal incremental output of compressed data
+ * Z_SYNC_FLUSH: do a SYNC_FLUSH, used by png_write_flush
+ * Z_FINISH: this is the end of the input, do a Z_FINISH and clean up
+ *
+ * The routine manages the acquire and release of the png_ptr->zstream by
+ * checking and (at the end) clearing png_ptr->zowner; it does some sanity
+ * checks on the 'mode' flags while doing this.
+ */
+void /* PRIVATE */
+png_compress_IDAT(png_structrp png_ptr, png_const_bytep input,
+ png_alloc_size_t input_len, int flush)
+{
+ if (png_ptr->zowner != png_IDAT)
+ {
+ /* First time. Ensure we have a temporary buffer for compression and
+ * trim the buffer list if it has more than one entry to free memory.
+ * If 'WRITE_COMPRESSED_TEXT' is not set the list will never have been
+ * created at this point, but the check here is quick and safe.
+ */
+ if (png_ptr->zbuffer_list == NULL)
+ {
+ png_ptr->zbuffer_list = png_voidcast(png_compression_bufferp,
+ png_malloc(png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr)));
+ png_ptr->zbuffer_list->next = NULL;
+ }
+
+ else
+ png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list->next);
+
+ /* It is a terminal error if we can't claim the zstream. */
+ if (png_deflate_claim(png_ptr, png_IDAT, png_image_size(png_ptr)) != Z_OK)
+ png_error(png_ptr, png_ptr->zstream.msg);
+
+ /* The output state is maintained in png_ptr->zstream, so it must be
+ * initialized here after the claim.
+ */
+ png_ptr->zstream.next_out = png_ptr->zbuffer_list->output;
+ png_ptr->zstream.avail_out = png_ptr->zbuffer_size;
+ }
+
+ /* Now loop reading and writing until all the input is consumed or an error
+ * terminates the operation. The _out values are maintained across calls to
+ * this function, but the input must be reset each time.
+ */
+ png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input);
+ png_ptr->zstream.avail_in = 0; /* set below */
+ for (;;)
+ {
+ int ret;
+
+ /* INPUT: from the row data */
+ uInt avail = ZLIB_IO_MAX;
+
+ if (avail > input_len)
+ avail = (uInt)input_len; /* safe because of the check */
+
+ png_ptr->zstream.avail_in = avail;
+ input_len -= avail;
+
+ ret = deflate(&png_ptr->zstream, input_len > 0 ? Z_NO_FLUSH : flush);
+
+ /* Include as-yet unconsumed input */
+ input_len += png_ptr->zstream.avail_in;
+ png_ptr->zstream.avail_in = 0;
+
+ /* OUTPUT: write complete IDAT chunks when avail_out drops to zero. Note
+ * that these two zstream fields are preserved across the calls, therefore
+ * there is no need to set these up on entry to the loop.
+ */
+ if (png_ptr->zstream.avail_out == 0)
+ {
+ png_bytep data = png_ptr->zbuffer_list->output;
+ uInt size = png_ptr->zbuffer_size;
+
+ /* Write an IDAT containing the data then reset the buffer. The
+ * first IDAT may need deflate header optimization.
+ */
+#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+ if ((png_ptr->mode & PNG_HAVE_IDAT) == 0 &&
+ png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
+ optimize_cmf(data, png_image_size(png_ptr));
+#endif
+
+ if (size > 0)
+ png_write_complete_chunk(png_ptr, png_IDAT, data, size);
+ png_ptr->mode |= PNG_HAVE_IDAT;
+
+ png_ptr->zstream.next_out = data;
+ png_ptr->zstream.avail_out = size;
+
+ /* For SYNC_FLUSH or FINISH it is essential to keep calling zlib with
+ * the same flush parameter until it has finished output, for NO_FLUSH
+ * it doesn't matter.
+ */
+ if (ret == Z_OK && flush != Z_NO_FLUSH)
+ continue;
+ }
+
+ /* The order of these checks doesn't matter much; it just affects which
+ * possible error might be detected if multiple things go wrong at once.
+ */
+ if (ret == Z_OK) /* most likely return code! */
+ {
+ /* If all the input has been consumed then just return. If Z_FINISH
+ * was used as the flush parameter something has gone wrong if we get
+ * here.
+ */
+ if (input_len == 0)
+ {
+ if (flush == Z_FINISH)
+ png_error(png_ptr, "Z_OK on Z_FINISH with output space");
+
+ return;
+ }
+ }
+
+ else if (ret == Z_STREAM_END && flush == Z_FINISH)
+ {
+ /* This is the end of the IDAT data; any pending output must be
+ * flushed. For small PNG files we may still be at the beginning.
+ */
+ png_bytep data = png_ptr->zbuffer_list->output;
+ uInt size = png_ptr->zbuffer_size - png_ptr->zstream.avail_out;
+
+#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+ if ((png_ptr->mode & PNG_HAVE_IDAT) == 0 &&
+ png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
+ optimize_cmf(data, png_image_size(png_ptr));
+#endif
+
+ if (size > 0)
+ png_write_complete_chunk(png_ptr, png_IDAT, data, size);
+ png_ptr->zstream.avail_out = 0;
+ png_ptr->zstream.next_out = NULL;
+ png_ptr->mode |= PNG_HAVE_IDAT | PNG_AFTER_IDAT;
+
+ png_ptr->zowner = 0; /* Release the stream */
+ return;
+ }
+
+ else
+ {
+ /* This is an error condition. */
+ png_zstream_error(png_ptr, ret);
+ png_error(png_ptr, png_ptr->zstream.msg);
+ }
+ }
+}
+
+/* Write an IEND chunk */
+void /* PRIVATE */
+png_write_IEND(png_structrp png_ptr)
+{
+ png_debug(1, "in png_write_IEND");
+
+ png_write_complete_chunk(png_ptr, png_IEND, NULL, 0);
+ png_ptr->mode |= PNG_HAVE_IEND;
+}
+
+#ifdef PNG_WRITE_gAMA_SUPPORTED
+/* Write a gAMA chunk */
+void /* PRIVATE */
+png_write_gAMA_fixed(png_structrp png_ptr, png_fixed_point file_gamma)
+{
+ png_byte buf[4];
+
+ png_debug(1, "in png_write_gAMA");
+
+ /* file_gamma is saved in 1/100,000ths */
+ png_save_uint_32(buf, (png_uint_32)file_gamma);
+ png_write_complete_chunk(png_ptr, png_gAMA, buf, 4);
+}
+#endif
+
+#ifdef PNG_WRITE_sRGB_SUPPORTED
+/* Write a sRGB chunk */
+void /* PRIVATE */
+png_write_sRGB(png_structrp png_ptr, int srgb_intent)
+{
+ png_byte buf[1];
+
+ png_debug(1, "in png_write_sRGB");
+
+ if (srgb_intent >= PNG_sRGB_INTENT_LAST)
+ png_warning(png_ptr,
+ "Invalid sRGB rendering intent specified");
+
+ buf[0]=(png_byte)srgb_intent;
+ png_write_complete_chunk(png_ptr, png_sRGB, buf, 1);
+}
+#endif
+
+#ifdef PNG_WRITE_iCCP_SUPPORTED
+/* Write an iCCP chunk */
+void /* PRIVATE */
+png_write_iCCP(png_structrp png_ptr, png_const_charp name,
+ png_const_bytep profile, png_uint_32 profile_len)
+{
+ png_uint_32 name_len;
+ png_byte new_name[81]; /* 1 byte for the compression byte */
+ compression_state comp;
+ png_uint_32 temp;
+
+ png_debug(1, "in png_write_iCCP");
+
+ /* These are all internal problems: the profile should have been checked
+ * before when it was stored.
+ */
+ if (profile == NULL)
+ png_error(png_ptr, "No profile for iCCP chunk"); /* internal error */
+
+ if (profile_len < 132)
+ png_error(png_ptr, "ICC profile too short");
+
+ if (png_get_uint_32(profile) != profile_len)
+ png_error(png_ptr, "Incorrect data in iCCP");
+
+ temp = (png_uint_32) (*(profile+8));
+ if (temp > 3 && (profile_len & 0x03))
+ png_error(png_ptr, "ICC profile length invalid (not a multiple of 4)");
+
+ {
+ png_uint_32 embedded_profile_len = png_get_uint_32(profile);
+
+ if (profile_len != embedded_profile_len)
+ png_error(png_ptr, "Profile length does not match profile");
+ }
+
+ name_len = png_check_keyword(png_ptr, name, new_name);
+
+ if (name_len == 0)
+ png_error(png_ptr, "iCCP: invalid keyword");
+
+ new_name[++name_len] = PNG_COMPRESSION_TYPE_BASE;
+
+ /* Make sure we include the NULL after the name and the compression type */
+ ++name_len;
+
+ png_text_compress_init(&comp, profile, profile_len);
+
+ /* Allow for keyword terminator and compression byte */
+ if (png_text_compress(png_ptr, png_iCCP, &comp, name_len) != Z_OK)
+ png_error(png_ptr, png_ptr->zstream.msg);
+
+ png_write_chunk_header(png_ptr, png_iCCP, name_len + comp.output_len);
+
+ png_write_chunk_data(png_ptr, new_name, name_len);
+
+ png_write_compressed_data_out(png_ptr, &comp);
+
+ png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_sPLT_SUPPORTED
+/* Write a sPLT chunk */
+void /* PRIVATE */
+png_write_sPLT(png_structrp png_ptr, png_const_sPLT_tp spalette)
+{
+ png_uint_32 name_len;
+ png_byte new_name[80];
+ png_byte entrybuf[10];
+ size_t entry_size = (spalette->depth == 8 ? 6 : 10);
+ size_t palette_size = entry_size * (size_t)spalette->nentries;
+ png_sPLT_entryp ep;
+#ifndef PNG_POINTER_INDEXING_SUPPORTED
+ int i;
+#endif
+
+ png_debug(1, "in png_write_sPLT");
+
+ name_len = png_check_keyword(png_ptr, spalette->name, new_name);
+
+ if (name_len == 0)
+ png_error(png_ptr, "sPLT: invalid keyword");
+
+ /* Make sure we include the NULL after the name */
+ png_write_chunk_header(png_ptr, png_sPLT,
+ (png_uint_32)(name_len + 2 + palette_size));
+
+ png_write_chunk_data(png_ptr, (png_bytep)new_name, (size_t)(name_len + 1));
+
+ png_write_chunk_data(png_ptr, &spalette->depth, 1);
+
+ /* Loop through each palette entry, writing appropriately */
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+ for (ep = spalette->entries; epentries + spalette->nentries; ep++)
+ {
+ if (spalette->depth == 8)
+ {
+ entrybuf[0] = (png_byte)ep->red;
+ entrybuf[1] = (png_byte)ep->green;
+ entrybuf[2] = (png_byte)ep->blue;
+ entrybuf[3] = (png_byte)ep->alpha;
+ png_save_uint_16(entrybuf + 4, ep->frequency);
+ }
+
+ else
+ {
+ png_save_uint_16(entrybuf + 0, ep->red);
+ png_save_uint_16(entrybuf + 2, ep->green);
+ png_save_uint_16(entrybuf + 4, ep->blue);
+ png_save_uint_16(entrybuf + 6, ep->alpha);
+ png_save_uint_16(entrybuf + 8, ep->frequency);
+ }
+
+ png_write_chunk_data(png_ptr, entrybuf, entry_size);
+ }
+#else
+ ep=spalette->entries;
+ for (i = 0; i>spalette->nentries; i++)
+ {
+ if (spalette->depth == 8)
+ {
+ entrybuf[0] = (png_byte)ep[i].red;
+ entrybuf[1] = (png_byte)ep[i].green;
+ entrybuf[2] = (png_byte)ep[i].blue;
+ entrybuf[3] = (png_byte)ep[i].alpha;
+ png_save_uint_16(entrybuf + 4, ep[i].frequency);
+ }
+
+ else
+ {
+ png_save_uint_16(entrybuf + 0, ep[i].red);
+ png_save_uint_16(entrybuf + 2, ep[i].green);
+ png_save_uint_16(entrybuf + 4, ep[i].blue);
+ png_save_uint_16(entrybuf + 6, ep[i].alpha);
+ png_save_uint_16(entrybuf + 8, ep[i].frequency);
+ }
+
+ png_write_chunk_data(png_ptr, entrybuf, entry_size);
+ }
+#endif
+
+ png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_sBIT_SUPPORTED
+/* Write the sBIT chunk */
+void /* PRIVATE */
+png_write_sBIT(png_structrp png_ptr, png_const_color_8p sbit, int color_type)
+{
+ png_byte buf[4];
+ size_t size;
+
+ png_debug(1, "in png_write_sBIT");
+
+ /* Make sure we don't depend upon the order of PNG_COLOR_8 */
+ if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
+ {
+ png_byte maxbits;
+
+ maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :
+ png_ptr->usr_bit_depth);
+
+ if (sbit->red == 0 || sbit->red > maxbits ||
+ sbit->green == 0 || sbit->green > maxbits ||
+ sbit->blue == 0 || sbit->blue > maxbits)
+ {
+ png_warning(png_ptr, "Invalid sBIT depth specified");
+ return;
+ }
+
+ buf[0] = sbit->red;
+ buf[1] = sbit->green;
+ buf[2] = sbit->blue;
+ size = 3;
+ }
+
+ else
+ {
+ if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)
+ {
+ png_warning(png_ptr, "Invalid sBIT depth specified");
+ return;
+ }
+
+ buf[0] = sbit->gray;
+ size = 1;
+ }
+
+ if ((color_type & PNG_COLOR_MASK_ALPHA) != 0)
+ {
+ if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)
+ {
+ png_warning(png_ptr, "Invalid sBIT depth specified");
+ return;
+ }
+
+ buf[size++] = sbit->alpha;
+ }
+
+ png_write_complete_chunk(png_ptr, png_sBIT, buf, size);
+}
+#endif
+
+#ifdef PNG_WRITE_cHRM_SUPPORTED
+/* Write the cHRM chunk */
+void /* PRIVATE */
+png_write_cHRM_fixed(png_structrp png_ptr, const png_xy *xy)
+{
+ png_byte buf[32];
+
+ png_debug(1, "in png_write_cHRM");
+
+ /* Each value is saved in 1/100,000ths */
+ png_save_int_32(buf, xy->whitex);
+ png_save_int_32(buf + 4, xy->whitey);
+
+ png_save_int_32(buf + 8, xy->redx);
+ png_save_int_32(buf + 12, xy->redy);
+
+ png_save_int_32(buf + 16, xy->greenx);
+ png_save_int_32(buf + 20, xy->greeny);
+
+ png_save_int_32(buf + 24, xy->bluex);
+ png_save_int_32(buf + 28, xy->bluey);
+
+ png_write_complete_chunk(png_ptr, png_cHRM, buf, 32);
+}
+#endif
+
+#ifdef PNG_WRITE_tRNS_SUPPORTED
+/* Write the tRNS chunk */
+void /* PRIVATE */
+png_write_tRNS(png_structrp png_ptr, png_const_bytep trans_alpha,
+ png_const_color_16p tran, int num_trans, int color_type)
+{
+ png_byte buf[6];
+
+ png_debug(1, "in png_write_tRNS");
+
+ if (color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
+ {
+ png_app_warning(png_ptr,
+ "Invalid number of transparent colors specified");
+ return;
+ }
+
+ /* Write the chunk out as it is */
+ png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha,
+ (size_t)num_trans);
+ }
+
+ else if (color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ /* One 16-bit value */
+ if (tran->gray >= (1 << png_ptr->bit_depth))
+ {
+ png_app_warning(png_ptr,
+ "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
+
+ return;
+ }
+
+ png_save_uint_16(buf, tran->gray);
+ png_write_complete_chunk(png_ptr, png_tRNS, buf, 2);
+ }
+
+ else if (color_type == PNG_COLOR_TYPE_RGB)
+ {
+ /* Three 16-bit values */
+ png_save_uint_16(buf, tran->red);
+ png_save_uint_16(buf + 2, tran->green);
+ png_save_uint_16(buf + 4, tran->blue);
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]) != 0)
+#else
+ if ((buf[0] | buf[2] | buf[4]) != 0)
+#endif
+ {
+ png_app_warning(png_ptr,
+ "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
+ return;
+ }
+
+ png_write_complete_chunk(png_ptr, png_tRNS, buf, 6);
+ }
+
+ else
+ {
+ png_app_warning(png_ptr, "Can't write tRNS with an alpha channel");
+ }
+}
+#endif
+
+#ifdef PNG_WRITE_bKGD_SUPPORTED
+/* Write the background chunk */
+void /* PRIVATE */
+png_write_bKGD(png_structrp png_ptr, png_const_color_16p back, int color_type)
+{
+ png_byte buf[6];
+
+ png_debug(1, "in png_write_bKGD");
+
+ if (color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+ (png_ptr->num_palette != 0 ||
+ (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0) &&
+#endif
+ back->index >= png_ptr->num_palette)
+ {
+ png_warning(png_ptr, "Invalid background palette index");
+ return;
+ }
+
+ buf[0] = back->index;
+ png_write_complete_chunk(png_ptr, png_bKGD, buf, 1);
+ }
+
+ else if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
+ {
+ png_save_uint_16(buf, back->red);
+ png_save_uint_16(buf + 2, back->green);
+ png_save_uint_16(buf + 4, back->blue);
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]) != 0)
+#else
+ if ((buf[0] | buf[2] | buf[4]) != 0)
+#endif
+ {
+ png_warning(png_ptr,
+ "Ignoring attempt to write 16-bit bKGD chunk "
+ "when bit_depth is 8");
+
+ return;
+ }
+
+ png_write_complete_chunk(png_ptr, png_bKGD, buf, 6);
+ }
+
+ else
+ {
+ if (back->gray >= (1 << png_ptr->bit_depth))
+ {
+ png_warning(png_ptr,
+ "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
+
+ return;
+ }
+
+ png_save_uint_16(buf, back->gray);
+ png_write_complete_chunk(png_ptr, png_bKGD, buf, 2);
+ }
+}
+#endif
+
+#ifdef PNG_WRITE_cICP_SUPPORTED
+/* Write the cICP data */
+void /* PRIVATE */
+png_write_cICP(png_structrp png_ptr,
+ png_byte colour_primaries, png_byte transfer_function,
+ png_byte matrix_coefficients, png_byte video_full_range_flag)
+{
+ png_byte buf[4];
+
+ png_debug(1, "in png_write_cICP");
+
+ png_write_chunk_header(png_ptr, png_cICP, 4);
+
+ buf[0] = colour_primaries;
+ buf[1] = transfer_function;
+ buf[2] = matrix_coefficients;
+ buf[3] = video_full_range_flag;
+ png_write_chunk_data(png_ptr, buf, 4);
+
+ png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_cLLI_SUPPORTED
+void /* PRIVATE */
+png_write_cLLI_fixed(png_structrp png_ptr, png_uint_32 maxCLL,
+ png_uint_32 maxFALL)
+{
+ png_byte buf[8];
+
+ png_debug(1, "in png_write_cLLI_fixed");
+
+ png_save_uint_32(buf, maxCLL);
+ png_save_uint_32(buf + 4, maxFALL);
+
+ png_write_complete_chunk(png_ptr, png_cLLI, buf, 8);
+}
+#endif
+
+#ifdef PNG_WRITE_mDCV_SUPPORTED
+void /* PRIVATE */
+png_write_mDCV_fixed(png_structrp png_ptr,
+ png_uint_16 red_x, png_uint_16 red_y,
+ png_uint_16 green_x, png_uint_16 green_y,
+ png_uint_16 blue_x, png_uint_16 blue_y,
+ png_uint_16 white_x, png_uint_16 white_y,
+ png_uint_32 maxDL, png_uint_32 minDL)
+{
+ png_byte buf[24];
+
+ png_debug(1, "in png_write_mDCV_fixed");
+
+ png_save_uint_16(buf + 0, red_x);
+ png_save_uint_16(buf + 2, red_y);
+ png_save_uint_16(buf + 4, green_x);
+ png_save_uint_16(buf + 6, green_y);
+ png_save_uint_16(buf + 8, blue_x);
+ png_save_uint_16(buf + 10, blue_y);
+ png_save_uint_16(buf + 12, white_x);
+ png_save_uint_16(buf + 14, white_y);
+ png_save_uint_32(buf + 16, maxDL);
+ png_save_uint_32(buf + 20, minDL);
+
+ png_write_complete_chunk(png_ptr, png_mDCV, buf, 24);
+}
+#endif
+
+#ifdef PNG_WRITE_eXIf_SUPPORTED
+/* Write the Exif data */
+void /* PRIVATE */
+png_write_eXIf(png_structrp png_ptr, png_bytep exif, int num_exif)
+{
+ int i;
+ png_byte buf[1];
+
+ png_debug(1, "in png_write_eXIf");
+
+ png_write_chunk_header(png_ptr, png_eXIf, (png_uint_32)(num_exif));
+
+ for (i = 0; i < num_exif; i++)
+ {
+ buf[0] = exif[i];
+ png_write_chunk_data(png_ptr, buf, 1);
+ }
+
+ png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_hIST_SUPPORTED
+/* Write the histogram */
+void /* PRIVATE */
+png_write_hIST(png_structrp png_ptr, png_const_uint_16p hist, int num_hist)
+{
+ int i;
+ png_byte buf[3];
+
+ png_debug(1, "in png_write_hIST");
+
+ if (num_hist > (int)png_ptr->num_palette)
+ {
+ png_debug2(3, "num_hist = %d, num_palette = %d", num_hist,
+ png_ptr->num_palette);
+
+ png_warning(png_ptr, "Invalid number of histogram entries specified");
+ return;
+ }
+
+ png_write_chunk_header(png_ptr, png_hIST, (png_uint_32)(num_hist * 2));
+
+ for (i = 0; i < num_hist; i++)
+ {
+ png_save_uint_16(buf, hist[i]);
+ png_write_chunk_data(png_ptr, buf, 2);
+ }
+
+ png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+/* Write a tEXt chunk */
+void /* PRIVATE */
+png_write_tEXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
+ size_t text_len)
+{
+ png_uint_32 key_len;
+ png_byte new_key[80];
+
+ png_debug(1, "in png_write_tEXt");
+
+ key_len = png_check_keyword(png_ptr, key, new_key);
+
+ if (key_len == 0)
+ png_error(png_ptr, "tEXt: invalid keyword");
+
+ if (text == NULL || *text == '\0')
+ text_len = 0;
+
+ else
+ text_len = strlen(text);
+
+ if (text_len > PNG_UINT_31_MAX - (key_len+1))
+ png_error(png_ptr, "tEXt: text too long");
+
+ /* Make sure we include the 0 after the key */
+ png_write_chunk_header(png_ptr, png_tEXt,
+ (png_uint_32)/*checked above*/(key_len + text_len + 1));
+ /*
+ * We leave it to the application to meet PNG-1.0 requirements on the
+ * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
+ * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
+ * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
+ */
+ png_write_chunk_data(png_ptr, new_key, key_len + 1);
+
+ if (text_len != 0)
+ png_write_chunk_data(png_ptr, (png_const_bytep)text, text_len);
+
+ png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+/* Write a compressed text chunk */
+void /* PRIVATE */
+png_write_zTXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
+ int compression)
+{
+ png_uint_32 key_len;
+ png_byte new_key[81];
+ compression_state comp;
+
+ png_debug(1, "in png_write_zTXt");
+
+ if (compression == PNG_TEXT_COMPRESSION_NONE)
+ {
+ png_write_tEXt(png_ptr, key, text, 0);
+ return;
+ }
+
+ if (compression != PNG_TEXT_COMPRESSION_zTXt)
+ png_error(png_ptr, "zTXt: invalid compression type");
+
+ key_len = png_check_keyword(png_ptr, key, new_key);
+
+ if (key_len == 0)
+ png_error(png_ptr, "zTXt: invalid keyword");
+
+ /* Add the compression method and 1 for the keyword separator. */
+ new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE;
+ ++key_len;
+
+ /* Compute the compressed data; do it now for the length */
+ png_text_compress_init(&comp, (png_const_bytep)text,
+ text == NULL ? 0 : strlen(text));
+
+ if (png_text_compress(png_ptr, png_zTXt, &comp, key_len) != Z_OK)
+ png_error(png_ptr, png_ptr->zstream.msg);
+
+ /* Write start of chunk */
+ png_write_chunk_header(png_ptr, png_zTXt, key_len + comp.output_len);
+
+ /* Write key */
+ png_write_chunk_data(png_ptr, new_key, key_len);
+
+ /* Write the compressed data */
+ png_write_compressed_data_out(png_ptr, &comp);
+
+ /* Close the chunk */
+ png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+/* Write an iTXt chunk */
+void /* PRIVATE */
+png_write_iTXt(png_structrp png_ptr, int compression, png_const_charp key,
+ png_const_charp lang, png_const_charp lang_key, png_const_charp text)
+{
+ png_uint_32 key_len, prefix_len;
+ size_t lang_len, lang_key_len;
+ png_byte new_key[82];
+ compression_state comp;
+
+ png_debug(1, "in png_write_iTXt");
+
+ key_len = png_check_keyword(png_ptr, key, new_key);
+
+ if (key_len == 0)
+ png_error(png_ptr, "iTXt: invalid keyword");
+
+ /* Set the compression flag */
+ switch (compression)
+ {
+ case PNG_ITXT_COMPRESSION_NONE:
+ case PNG_TEXT_COMPRESSION_NONE:
+ compression = new_key[++key_len] = 0; /* no compression */
+ break;
+
+ case PNG_TEXT_COMPRESSION_zTXt:
+ case PNG_ITXT_COMPRESSION_zTXt:
+ compression = new_key[++key_len] = 1; /* compressed */
+ break;
+
+ default:
+ png_error(png_ptr, "iTXt: invalid compression");
+ }
+
+ new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE;
+ ++key_len; /* for the keywod separator */
+
+ /* We leave it to the application to meet PNG-1.0 requirements on the
+ * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
+ * any non-Latin-1 characters except for NEWLINE. ISO PNG, however,
+ * specifies that the text is UTF-8 and this really doesn't require any
+ * checking.
+ *
+ * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
+ *
+ * TODO: validate the language tag correctly (see the spec.)
+ */
+ if (lang == NULL) lang = ""; /* empty language is valid */
+ lang_len = strlen(lang)+1;
+ if (lang_key == NULL) lang_key = ""; /* may be empty */
+ lang_key_len = strlen(lang_key)+1;
+ if (text == NULL) text = ""; /* may be empty */
+
+ prefix_len = key_len;
+ if (lang_len > PNG_UINT_31_MAX-prefix_len)
+ prefix_len = PNG_UINT_31_MAX;
+ else
+ prefix_len = (png_uint_32)(prefix_len + lang_len);
+
+ if (lang_key_len > PNG_UINT_31_MAX-prefix_len)
+ prefix_len = PNG_UINT_31_MAX;
+ else
+ prefix_len = (png_uint_32)(prefix_len + lang_key_len);
+
+ png_text_compress_init(&comp, (png_const_bytep)text, strlen(text));
+
+ if (compression != 0)
+ {
+ if (png_text_compress(png_ptr, png_iTXt, &comp, prefix_len) != Z_OK)
+ png_error(png_ptr, png_ptr->zstream.msg);
+ }
+
+ else
+ {
+ if (comp.input_len > PNG_UINT_31_MAX-prefix_len)
+ png_error(png_ptr, "iTXt: uncompressed text too long");
+
+ /* So the string will fit in a chunk: */
+ comp.output_len = (png_uint_32)/*SAFE*/comp.input_len;
+ }
+
+ png_write_chunk_header(png_ptr, png_iTXt, comp.output_len + prefix_len);
+
+ png_write_chunk_data(png_ptr, new_key, key_len);
+
+ png_write_chunk_data(png_ptr, (png_const_bytep)lang, lang_len);
+
+ png_write_chunk_data(png_ptr, (png_const_bytep)lang_key, lang_key_len);
+
+ if (compression != 0)
+ png_write_compressed_data_out(png_ptr, &comp);
+
+ else
+ png_write_chunk_data(png_ptr, (png_const_bytep)text, comp.output_len);
+
+ png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_oFFs_SUPPORTED
+/* Write the oFFs chunk */
+void /* PRIVATE */
+png_write_oFFs(png_structrp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
+ int unit_type)
+{
+ png_byte buf[9];
+
+ png_debug(1, "in png_write_oFFs");
+
+ if (unit_type >= PNG_OFFSET_LAST)
+ png_warning(png_ptr, "Unrecognized unit type for oFFs chunk");
+
+ png_save_int_32(buf, x_offset);
+ png_save_int_32(buf + 4, y_offset);
+ buf[8] = (png_byte)unit_type;
+
+ png_write_complete_chunk(png_ptr, png_oFFs, buf, 9);
+}
+#endif
+#ifdef PNG_WRITE_pCAL_SUPPORTED
+/* Write the pCAL chunk (described in the PNG extensions document) */
+void /* PRIVATE */
+png_write_pCAL(png_structrp png_ptr, png_charp purpose, png_int_32 X0,
+ png_int_32 X1, int type, int nparams, png_const_charp units,
+ png_charpp params)
+{
+ png_uint_32 purpose_len;
+ size_t units_len, total_len;
+ size_t *params_len;
+ png_byte buf[10];
+ png_byte new_purpose[80];
+ int i;
+
+ png_debug1(1, "in png_write_pCAL (%d parameters)", nparams);
+
+ if (type >= PNG_EQUATION_LAST)
+ png_error(png_ptr, "Unrecognized equation type for pCAL chunk");
+
+ purpose_len = png_check_keyword(png_ptr, purpose, new_purpose);
+
+ if (purpose_len == 0)
+ png_error(png_ptr, "pCAL: invalid keyword");
+
+ ++purpose_len; /* terminator */
+
+ png_debug1(3, "pCAL purpose length = %d", (int)purpose_len);
+ units_len = strlen(units) + (nparams == 0 ? 0 : 1);
+ png_debug1(3, "pCAL units length = %d", (int)units_len);
+ total_len = purpose_len + units_len + 10;
+
+ params_len = (size_t *)png_malloc(png_ptr,
+ (png_alloc_size_t)((png_alloc_size_t)nparams * (sizeof (size_t))));
+
+ /* Find the length of each parameter, making sure we don't count the
+ * null terminator for the last parameter.
+ */
+ for (i = 0; i < nparams; i++)
+ {
+ params_len[i] = strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
+ png_debug2(3, "pCAL parameter %d length = %lu", i,
+ (unsigned long)params_len[i]);
+ total_len += params_len[i];
+ }
+
+ png_debug1(3, "pCAL total length = %d", (int)total_len);
+ png_write_chunk_header(png_ptr, png_pCAL, (png_uint_32)total_len);
+ png_write_chunk_data(png_ptr, new_purpose, purpose_len);
+ png_save_int_32(buf, X0);
+ png_save_int_32(buf + 4, X1);
+ buf[8] = (png_byte)type;
+ buf[9] = (png_byte)nparams;
+ png_write_chunk_data(png_ptr, buf, 10);
+ png_write_chunk_data(png_ptr, (png_const_bytep)units, (size_t)units_len);
+
+ for (i = 0; i < nparams; i++)
+ {
+ png_write_chunk_data(png_ptr, (png_const_bytep)params[i], params_len[i]);
+ }
+
+ png_free(png_ptr, params_len);
+ png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_sCAL_SUPPORTED
+/* Write the sCAL chunk */
+void /* PRIVATE */
+png_write_sCAL_s(png_structrp png_ptr, int unit, png_const_charp width,
+ png_const_charp height)
+{
+ png_byte buf[64];
+ size_t wlen, hlen, total_len;
+
+ png_debug(1, "in png_write_sCAL_s");
+
+ wlen = strlen(width);
+ hlen = strlen(height);
+ total_len = wlen + hlen + 2;
+
+ if (total_len > 64)
+ {
+ png_warning(png_ptr, "Can't write sCAL (buffer too small)");
+ return;
+ }
+
+ buf[0] = (png_byte)unit;
+ memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */
+ memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */
+
+ png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
+ png_write_complete_chunk(png_ptr, png_sCAL, buf, total_len);
+}
+#endif
+
+#ifdef PNG_WRITE_pHYs_SUPPORTED
+/* Write the pHYs chunk */
+void /* PRIVATE */
+png_write_pHYs(png_structrp png_ptr, png_uint_32 x_pixels_per_unit,
+ png_uint_32 y_pixels_per_unit,
+ int unit_type)
+{
+ png_byte buf[9];
+
+ png_debug(1, "in png_write_pHYs");
+
+ if (unit_type >= PNG_RESOLUTION_LAST)
+ png_warning(png_ptr, "Unrecognized unit type for pHYs chunk");
+
+ png_save_uint_32(buf, x_pixels_per_unit);
+ png_save_uint_32(buf + 4, y_pixels_per_unit);
+ buf[8] = (png_byte)unit_type;
+
+ png_write_complete_chunk(png_ptr, png_pHYs, buf, 9);
+}
+#endif
+
+#ifdef PNG_WRITE_tIME_SUPPORTED
+/* Write the tIME chunk. Use either png_convert_from_struct_tm()
+ * or png_convert_from_time_t(), or fill in the structure yourself.
+ */
+void /* PRIVATE */
+png_write_tIME(png_structrp png_ptr, png_const_timep mod_time)
+{
+ png_byte buf[7];
+
+ png_debug(1, "in png_write_tIME");
+
+ if (mod_time->month > 12 || mod_time->month < 1 ||
+ mod_time->day > 31 || mod_time->day < 1 ||
+ mod_time->hour > 23 || mod_time->second > 60)
+ {
+ png_warning(png_ptr, "Invalid time specified for tIME chunk");
+ return;
+ }
+
+ png_save_uint_16(buf, mod_time->year);
+ buf[2] = mod_time->month;
+ buf[3] = mod_time->day;
+ buf[4] = mod_time->hour;
+ buf[5] = mod_time->minute;
+ buf[6] = mod_time->second;
+
+ png_write_complete_chunk(png_ptr, png_tIME, buf, 7);
+}
+#endif
+
+/* Initializes the row writing capability of libpng */
+void /* PRIVATE */
+png_write_start_row(png_structrp png_ptr)
+{
+ png_alloc_size_t buf_size;
+ int usr_pixel_depth;
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ png_byte filters;
+#endif
+
+ png_debug(1, "in png_write_start_row");
+
+ usr_pixel_depth = png_ptr->usr_channels * png_ptr->usr_bit_depth;
+ buf_size = PNG_ROWBYTES(usr_pixel_depth, png_ptr->width) + 1;
+
+ /* 1.5.6: added to allow checking in the row write code. */
+ png_ptr->transformed_pixel_depth = png_ptr->pixel_depth;
+ png_ptr->maximum_pixel_depth = (png_byte)usr_pixel_depth;
+
+ /* Set up row buffer */
+ png_ptr->row_buf = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size));
+
+ png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ filters = png_ptr->do_filter;
+
+ if (png_ptr->height == 1)
+ filters &= 0xff & ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH);
+
+ if (png_ptr->width == 1)
+ filters &= 0xff & ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH);
+
+ if (filters == 0)
+ filters = PNG_FILTER_NONE;
+
+ png_ptr->do_filter = filters;
+
+ if (((filters & (PNG_FILTER_SUB | PNG_FILTER_UP | PNG_FILTER_AVG |
+ PNG_FILTER_PAETH)) != 0) && png_ptr->try_row == NULL)
+ {
+ int num_filters = 0;
+
+ png_ptr->try_row = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size));
+
+ if (filters & PNG_FILTER_SUB)
+ num_filters++;
+
+ if (filters & PNG_FILTER_UP)
+ num_filters++;
+
+ if (filters & PNG_FILTER_AVG)
+ num_filters++;
+
+ if (filters & PNG_FILTER_PAETH)
+ num_filters++;
+
+ if (num_filters > 1)
+ png_ptr->tst_row = png_voidcast(png_bytep, png_malloc(png_ptr,
+ buf_size));
+ }
+
+ /* We only need to keep the previous row if we are using one of the following
+ * filters.
+ */
+ if ((filters & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH)) != 0)
+ png_ptr->prev_row = png_voidcast(png_bytep,
+ png_calloc(png_ptr, buf_size));
+#endif /* WRITE_FILTER */
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* If interlaced, we need to set up width and height of pass */
+ if (png_ptr->interlaced != 0)
+ {
+ if ((png_ptr->transformations & PNG_INTERLACE) == 0)
+ {
+ png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
+ png_pass_ystart[0]) / png_pass_yinc[0];
+
+ png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -
+ png_pass_start[0]) / png_pass_inc[0];
+ }
+
+ else
+ {
+ png_ptr->num_rows = png_ptr->height;
+ png_ptr->usr_width = png_ptr->width;
+ }
+ }
+
+ else
+#endif
+ {
+ png_ptr->num_rows = png_ptr->height;
+ png_ptr->usr_width = png_ptr->width;
+ }
+}
+
+/* Internal use only. Called when finished processing a row of data. */
+void /* PRIVATE */
+png_write_finish_row(png_structrp png_ptr)
+{
+ png_debug(1, "in png_write_finish_row");
+
+ /* Next row */
+ png_ptr->row_number++;
+
+ /* See if we are done */
+ if (png_ptr->row_number < png_ptr->num_rows)
+ return;
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+ /* If interlaced, go to next pass */
+ if (png_ptr->interlaced != 0)
+ {
+ png_ptr->row_number = 0;
+ if ((png_ptr->transformations & PNG_INTERLACE) != 0)
+ {
+ png_ptr->pass++;
+ }
+
+ else
+ {
+ /* Loop until we find a non-zero width or height pass */
+ do
+ {
+ png_ptr->pass++;
+
+ if (png_ptr->pass >= 7)
+ break;
+
+ png_ptr->usr_width = (png_ptr->width +
+ png_pass_inc[png_ptr->pass] - 1 -
+ png_pass_start[png_ptr->pass]) /
+ png_pass_inc[png_ptr->pass];
+
+ png_ptr->num_rows = (png_ptr->height +
+ png_pass_yinc[png_ptr->pass] - 1 -
+ png_pass_ystart[png_ptr->pass]) /
+ png_pass_yinc[png_ptr->pass];
+
+ if ((png_ptr->transformations & PNG_INTERLACE) != 0)
+ break;
+
+ } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);
+
+ }
+
+ /* Reset the row above the image for the next pass */
+ if (png_ptr->pass < 7)
+ {
+ if (png_ptr->prev_row != NULL)
+ memset(png_ptr->prev_row, 0,
+ PNG_ROWBYTES(png_ptr->usr_channels *
+ png_ptr->usr_bit_depth, png_ptr->width) + 1);
+
+ return;
+ }
+ }
+#endif
+
+ /* If we get here, we've just written the last row, so we need
+ to flush the compressor */
+ png_compress_IDAT(png_ptr, NULL, 0, Z_FINISH);
+}
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+/* Pick out the correct pixels for the interlace pass.
+ * The basic idea here is to go through the row with a source
+ * pointer and a destination pointer (sp and dp), and copy the
+ * correct pixels for the pass. As the row gets compacted,
+ * sp will always be >= dp, so we should never overwrite anything.
+ * See the default: case for the easiest code to understand.
+ */
+void /* PRIVATE */
+png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
+{
+ png_debug(1, "in png_do_write_interlace");
+
+ /* We don't have to do anything on the last pass (6) */
+ if (pass < 6)
+ {
+ /* Each pixel depth is handled separately */
+ switch (row_info->pixel_depth)
+ {
+ case 1:
+ {
+ png_bytep sp;
+ png_bytep dp;
+ unsigned int shift;
+ int d;
+ int value;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ dp = row;
+ d = 0;
+ shift = 7;
+
+ for (i = png_pass_start[pass]; i < row_width;
+ i += png_pass_inc[pass])
+ {
+ sp = row + (size_t)(i >> 3);
+ value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01;
+ d |= (value << shift);
+
+ if (shift == 0)
+ {
+ shift = 7;
+ *dp++ = (png_byte)d;
+ d = 0;
+ }
+
+ else
+ shift--;
+
+ }
+ if (shift != 7)
+ *dp = (png_byte)d;
+
+ break;
+ }
+
+ case 2:
+ {
+ png_bytep sp;
+ png_bytep dp;
+ unsigned int shift;
+ int d;
+ int value;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ dp = row;
+ shift = 6;
+ d = 0;
+
+ for (i = png_pass_start[pass]; i < row_width;
+ i += png_pass_inc[pass])
+ {
+ sp = row + (size_t)(i >> 2);
+ value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03;
+ d |= (value << shift);
+
+ if (shift == 0)
+ {
+ shift = 6;
+ *dp++ = (png_byte)d;
+ d = 0;
+ }
+
+ else
+ shift -= 2;
+ }
+ if (shift != 6)
+ *dp = (png_byte)d;
+
+ break;
+ }
+
+ case 4:
+ {
+ png_bytep sp;
+ png_bytep dp;
+ unsigned int shift;
+ int d;
+ int value;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ dp = row;
+ shift = 4;
+ d = 0;
+ for (i = png_pass_start[pass]; i < row_width;
+ i += png_pass_inc[pass])
+ {
+ sp = row + (size_t)(i >> 1);
+ value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;
+ d |= (value << shift);
+
+ if (shift == 0)
+ {
+ shift = 4;
+ *dp++ = (png_byte)d;
+ d = 0;
+ }
+
+ else
+ shift -= 4;
+ }
+ if (shift != 4)
+ *dp = (png_byte)d;
+
+ break;
+ }
+
+ default:
+ {
+ png_bytep sp;
+ png_bytep dp;
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+ size_t pixel_bytes;
+
+ /* Start at the beginning */
+ dp = row;
+
+ /* Find out how many bytes each pixel takes up */
+ pixel_bytes = (row_info->pixel_depth >> 3);
+
+ /* Loop through the row, only looking at the pixels that matter */
+ for (i = png_pass_start[pass]; i < row_width;
+ i += png_pass_inc[pass])
+ {
+ /* Find out where the original pixel is */
+ sp = row + (size_t)i * pixel_bytes;
+
+ /* Move the pixel */
+ if (dp != sp)
+ memcpy(dp, sp, pixel_bytes);
+
+ /* Next pixel */
+ dp += pixel_bytes;
+ }
+ break;
+ }
+ }
+ /* Set new row width */
+ row_info->width = (row_info->width +
+ png_pass_inc[pass] - 1 -
+ png_pass_start[pass]) /
+ png_pass_inc[pass];
+
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
+ row_info->width);
+ }
+}
+#endif
+
+
+/* This filters the row, chooses which filter to use, if it has not already
+ * been specified by the application, and then writes the row out with the
+ * chosen filter.
+ */
+static void /* PRIVATE */
+png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row,
+ size_t row_bytes);
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+static size_t /* PRIVATE */
+png_setup_sub_row(png_structrp png_ptr, png_uint_32 bpp,
+ size_t row_bytes, size_t lmins)
+{
+ png_bytep rp, dp, lp;
+ size_t i;
+ size_t sum = 0;
+ unsigned int v;
+
+ png_ptr->try_row[0] = PNG_FILTER_VALUE_SUB;
+
+ for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1; i < bpp;
+ i++, rp++, dp++)
+ {
+ v = *dp = *rp;
+#ifdef PNG_USE_ABS
+ sum += 128 - abs((int)v - 128);
+#else
+ sum += (v < 128) ? v : 256 - v;
+#endif
+ }
+
+ for (lp = png_ptr->row_buf + 1; i < row_bytes;
+ i++, rp++, lp++, dp++)
+ {
+ v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
+#ifdef PNG_USE_ABS
+ sum += 128 - abs((int)v - 128);
+#else
+ sum += (v < 128) ? v : 256 - v;
+#endif
+
+ if (sum > lmins) /* We are already worse, don't continue. */
+ break;
+ }
+
+ return sum;
+}
+
+static void /* PRIVATE */
+png_setup_sub_row_only(png_structrp png_ptr, png_uint_32 bpp,
+ size_t row_bytes)
+{
+ png_bytep rp, dp, lp;
+ size_t i;
+
+ png_ptr->try_row[0] = PNG_FILTER_VALUE_SUB;
+
+ for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1; i < bpp;
+ i++, rp++, dp++)
+ {
+ *dp = *rp;
+ }
+
+ for (lp = png_ptr->row_buf + 1; i < row_bytes;
+ i++, rp++, lp++, dp++)
+ {
+ *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
+ }
+}
+
+static size_t /* PRIVATE */
+png_setup_up_row(png_structrp png_ptr, size_t row_bytes, size_t lmins)
+{
+ png_bytep rp, dp, pp;
+ size_t i;
+ size_t sum = 0;
+ unsigned int v;
+
+ png_ptr->try_row[0] = PNG_FILTER_VALUE_UP;
+
+ for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+ pp = png_ptr->prev_row + 1; i < row_bytes;
+ i++, rp++, pp++, dp++)
+ {
+ v = *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
+#ifdef PNG_USE_ABS
+ sum += 128 - abs((int)v - 128);
+#else
+ sum += (v < 128) ? v : 256 - v;
+#endif
+
+ if (sum > lmins) /* We are already worse, don't continue. */
+ break;
+ }
+
+ return sum;
+}
+static void /* PRIVATE */
+png_setup_up_row_only(png_structrp png_ptr, size_t row_bytes)
+{
+ png_bytep rp, dp, pp;
+ size_t i;
+
+ png_ptr->try_row[0] = PNG_FILTER_VALUE_UP;
+
+ for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+ pp = png_ptr->prev_row + 1; i < row_bytes;
+ i++, rp++, pp++, dp++)
+ {
+ *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
+ }
+}
+
+static size_t /* PRIVATE */
+png_setup_avg_row(png_structrp png_ptr, png_uint_32 bpp,
+ size_t row_bytes, size_t lmins)
+{
+ png_bytep rp, dp, pp, lp;
+ png_uint_32 i;
+ size_t sum = 0;
+ unsigned int v;
+
+ png_ptr->try_row[0] = PNG_FILTER_VALUE_AVG;
+
+ for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+ pp = png_ptr->prev_row + 1; i < bpp; i++)
+ {
+ v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
+
+#ifdef PNG_USE_ABS
+ sum += 128 - abs((int)v - 128);
+#else
+ sum += (v < 128) ? v : 256 - v;
+#endif
+ }
+
+ for (lp = png_ptr->row_buf + 1; i < row_bytes; i++)
+ {
+ v = *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
+ & 0xff);
+
+#ifdef PNG_USE_ABS
+ sum += 128 - abs((int)v - 128);
+#else
+ sum += (v < 128) ? v : 256 - v;
+#endif
+
+ if (sum > lmins) /* We are already worse, don't continue. */
+ break;
+ }
+
+ return sum;
+}
+static void /* PRIVATE */
+png_setup_avg_row_only(png_structrp png_ptr, png_uint_32 bpp,
+ size_t row_bytes)
+{
+ png_bytep rp, dp, pp, lp;
+ png_uint_32 i;
+
+ png_ptr->try_row[0] = PNG_FILTER_VALUE_AVG;
+
+ for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+ pp = png_ptr->prev_row + 1; i < bpp; i++)
+ {
+ *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
+ }
+
+ for (lp = png_ptr->row_buf + 1; i < row_bytes; i++)
+ {
+ *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
+ & 0xff);
+ }
+}
+
+static size_t /* PRIVATE */
+png_setup_paeth_row(png_structrp png_ptr, png_uint_32 bpp,
+ size_t row_bytes, size_t lmins)
+{
+ png_bytep rp, dp, pp, cp, lp;
+ size_t i;
+ size_t sum = 0;
+ unsigned int v;
+
+ png_ptr->try_row[0] = PNG_FILTER_VALUE_PAETH;
+
+ for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+ pp = png_ptr->prev_row + 1; i < bpp; i++)
+ {
+ v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
+
+#ifdef PNG_USE_ABS
+ sum += 128 - abs((int)v - 128);
+#else
+ sum += (v < 128) ? v : 256 - v;
+#endif
+ }
+
+ for (lp = png_ptr->row_buf + 1, cp = png_ptr->prev_row + 1; i < row_bytes;
+ i++)
+ {
+ int a, b, c, pa, pb, pc, p;
+
+ b = *pp++;
+ c = *cp++;
+ a = *lp++;
+
+ p = b - c;
+ pc = a - c;
+
+#ifdef PNG_USE_ABS
+ pa = abs(p);
+ pb = abs(pc);
+ pc = abs(p + pc);
+#else
+ pa = p < 0 ? -p : p;
+ pb = pc < 0 ? -pc : pc;
+ pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#endif
+
+ p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
+
+ v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
+
+#ifdef PNG_USE_ABS
+ sum += 128 - abs((int)v - 128);
+#else
+ sum += (v < 128) ? v : 256 - v;
+#endif
+
+ if (sum > lmins) /* We are already worse, don't continue. */
+ break;
+ }
+
+ return sum;
+}
+static void /* PRIVATE */
+png_setup_paeth_row_only(png_structrp png_ptr, png_uint_32 bpp,
+ size_t row_bytes)
+{
+ png_bytep rp, dp, pp, cp, lp;
+ size_t i;
+
+ png_ptr->try_row[0] = PNG_FILTER_VALUE_PAETH;
+
+ for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+ pp = png_ptr->prev_row + 1; i < bpp; i++)
+ {
+ *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
+ }
+
+ for (lp = png_ptr->row_buf + 1, cp = png_ptr->prev_row + 1; i < row_bytes;
+ i++)
+ {
+ int a, b, c, pa, pb, pc, p;
+
+ b = *pp++;
+ c = *cp++;
+ a = *lp++;
+
+ p = b - c;
+ pc = a - c;
+
+#ifdef PNG_USE_ABS
+ pa = abs(p);
+ pb = abs(pc);
+ pc = abs(p + pc);
+#else
+ pa = p < 0 ? -p : p;
+ pb = pc < 0 ? -pc : pc;
+ pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#endif
+
+ p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
+
+ *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
+ }
+}
+#endif /* WRITE_FILTER */
+
+void /* PRIVATE */
+png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
+{
+#ifndef PNG_WRITE_FILTER_SUPPORTED
+ png_write_filtered_row(png_ptr, png_ptr->row_buf, row_info->rowbytes+1);
+#else
+ unsigned int filter_to_do = png_ptr->do_filter;
+ png_bytep row_buf;
+ png_bytep best_row;
+ png_uint_32 bpp;
+ size_t mins;
+ size_t row_bytes = row_info->rowbytes;
+
+ png_debug(1, "in png_write_find_filter");
+
+ /* Find out how many bytes offset each pixel is */
+ bpp = (row_info->pixel_depth + 7) >> 3;
+
+ row_buf = png_ptr->row_buf;
+ mins = PNG_SIZE_MAX - 256/* so we can detect potential overflow of the
+ running sum */;
+
+ /* The prediction method we use is to find which method provides the
+ * smallest value when summing the absolute values of the distances
+ * from zero, using anything >= 128 as negative numbers. This is known
+ * as the "minimum sum of absolute differences" heuristic. Other
+ * heuristics are the "weighted minimum sum of absolute differences"
+ * (experimental and can in theory improve compression), and the "zlib
+ * predictive" method (not implemented yet), which does test compressions
+ * of lines using different filter methods, and then chooses the
+ * (series of) filter(s) that give minimum compressed data size (VERY
+ * computationally expensive).
+ *
+ * GRR 980525: consider also
+ *
+ * (1) minimum sum of absolute differences from running average (i.e.,
+ * keep running sum of non-absolute differences & count of bytes)
+ * [track dispersion, too? restart average if dispersion too large?]
+ *
+ * (1b) minimum sum of absolute differences from sliding average, probably
+ * with window size <= deflate window (usually 32K)
+ *
+ * (2) minimum sum of squared differences from zero or running average
+ * (i.e., ~ root-mean-square approach)
+ */
+
+
+ /* We don't need to test the 'no filter' case if this is the only filter
+ * that has been chosen, as it doesn't actually do anything to the data.
+ */
+ best_row = png_ptr->row_buf;
+
+ if (PNG_SIZE_MAX/128 <= row_bytes)
+ {
+ /* Overflow can occur in the calculation, just select the lowest set
+ * filter.
+ */
+ filter_to_do &= 0U-filter_to_do;
+ }
+ else if ((filter_to_do & PNG_FILTER_NONE) != 0 &&
+ filter_to_do != PNG_FILTER_NONE)
+ {
+ /* Overflow not possible and multiple filters in the list, including the
+ * 'none' filter.
+ */
+ png_bytep rp;
+ size_t sum = 0;
+ size_t i;
+ unsigned int v;
+
+ {
+ for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
+ {
+ v = *rp;
+#ifdef PNG_USE_ABS
+ sum += 128 - abs((int)v - 128);
+#else
+ sum += (v < 128) ? v : 256 - v;
+#endif
+ }
+ }
+
+ mins = sum;
+ }
+
+ /* Sub filter */
+ if (filter_to_do == PNG_FILTER_SUB)
+ /* It's the only filter so no testing is needed */
+ {
+ png_setup_sub_row_only(png_ptr, bpp, row_bytes);
+ best_row = png_ptr->try_row;
+ }
+
+ else if ((filter_to_do & PNG_FILTER_SUB) != 0)
+ {
+ size_t sum;
+ size_t lmins = mins;
+
+ sum = png_setup_sub_row(png_ptr, bpp, row_bytes, lmins);
+
+ if (sum < mins)
+ {
+ mins = sum;
+ best_row = png_ptr->try_row;
+ if (png_ptr->tst_row != NULL)
+ {
+ png_ptr->try_row = png_ptr->tst_row;
+ png_ptr->tst_row = best_row;
+ }
+ }
+ }
+
+ /* Up filter */
+ if (filter_to_do == PNG_FILTER_UP)
+ {
+ png_setup_up_row_only(png_ptr, row_bytes);
+ best_row = png_ptr->try_row;
+ }
+
+ else if ((filter_to_do & PNG_FILTER_UP) != 0)
+ {
+ size_t sum;
+ size_t lmins = mins;
+
+ sum = png_setup_up_row(png_ptr, row_bytes, lmins);
+
+ if (sum < mins)
+ {
+ mins = sum;
+ best_row = png_ptr->try_row;
+ if (png_ptr->tst_row != NULL)
+ {
+ png_ptr->try_row = png_ptr->tst_row;
+ png_ptr->tst_row = best_row;
+ }
+ }
+ }
+
+ /* Avg filter */
+ if (filter_to_do == PNG_FILTER_AVG)
+ {
+ png_setup_avg_row_only(png_ptr, bpp, row_bytes);
+ best_row = png_ptr->try_row;
+ }
+
+ else if ((filter_to_do & PNG_FILTER_AVG) != 0)
+ {
+ size_t sum;
+ size_t lmins = mins;
+
+ sum= png_setup_avg_row(png_ptr, bpp, row_bytes, lmins);
+
+ if (sum < mins)
+ {
+ mins = sum;
+ best_row = png_ptr->try_row;
+ if (png_ptr->tst_row != NULL)
+ {
+ png_ptr->try_row = png_ptr->tst_row;
+ png_ptr->tst_row = best_row;
+ }
+ }
+ }
+
+ /* Paeth filter */
+ if (filter_to_do == PNG_FILTER_PAETH)
+ {
+ png_setup_paeth_row_only(png_ptr, bpp, row_bytes);
+ best_row = png_ptr->try_row;
+ }
+
+ else if ((filter_to_do & PNG_FILTER_PAETH) != 0)
+ {
+ size_t sum;
+ size_t lmins = mins;
+
+ sum = png_setup_paeth_row(png_ptr, bpp, row_bytes, lmins);
+
+ if (sum < mins)
+ {
+ best_row = png_ptr->try_row;
+ if (png_ptr->tst_row != NULL)
+ {
+ png_ptr->try_row = png_ptr->tst_row;
+ png_ptr->tst_row = best_row;
+ }
+ }
+ }
+
+ /* Do the actual writing of the filtered row data from the chosen filter. */
+ png_write_filtered_row(png_ptr, best_row, row_info->rowbytes+1);
+
+#endif /* WRITE_FILTER */
+}
+
+
+/* Do the actual writing of a previously filtered row. */
+static void
+png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row,
+ size_t full_row_length/*includes filter byte*/)
+{
+ png_debug(1, "in png_write_filtered_row");
+
+ png_debug1(2, "filter = %d", filtered_row[0]);
+
+ png_compress_IDAT(png_ptr, filtered_row, full_row_length, Z_NO_FLUSH);
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ /* Swap the current and previous rows */
+ if (png_ptr->prev_row != NULL)
+ {
+ png_bytep tptr;
+
+ tptr = png_ptr->prev_row;
+ png_ptr->prev_row = png_ptr->row_buf;
+ png_ptr->row_buf = tptr;
+ }
+#endif /* WRITE_FILTER */
+
+ /* Finish row - updates counters and flushes zlib if last row */
+ png_write_finish_row(png_ptr);
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+ png_ptr->flush_rows++;
+
+ if (png_ptr->flush_dist > 0 &&
+ png_ptr->flush_rows >= png_ptr->flush_dist)
+ {
+ png_write_flush(png_ptr);
+ }
+#endif /* WRITE_FLUSH */
+}
+#endif /* WRITE */
diff --git a/libs/imagequant/proguard-rules.pro b/libs/imagequant/proguard-rules.pro
new file mode 100644
index 00000000..481bb434
--- /dev/null
+++ b/libs/imagequant/proguard-rules.pro
@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+# http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+# public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile
\ No newline at end of file
diff --git a/libs/paddleocr/build.gradle b/libs/paddleocr/build.gradle
index e83d8a13..f70b1d32 100644
--- a/libs/paddleocr/build.gradle
+++ b/libs/paddleocr/build.gradle
@@ -121,12 +121,12 @@ android {
}
compileOptions {
- sourceCompatibility JavaVersion.VERSION_17
- targetCompatibility JavaVersion.VERSION_17
+ sourceCompatibility = JavaVersion.toVersion(project.ext.javaVersion)
+ targetCompatibility = JavaVersion.toVersion(project.ext.javaVersion)
}
kotlinOptions {
- jvmTarget = JavaVersion.VERSION_17.majorVersion
+ jvmTarget = project.ext.javaVersion
}
externalNativeBuild {
diff --git a/libs/rapidocr/build.gradle b/libs/rapidocr/build.gradle
index d3c76289..f079108f 100644
--- a/libs/rapidocr/build.gradle
+++ b/libs/rapidocr/build.gradle
@@ -81,12 +81,12 @@ android {
}
compileOptions {
- sourceCompatibility JavaVersion.VERSION_17
- targetCompatibility JavaVersion.VERSION_17
+ sourceCompatibility = JavaVersion.toVersion(project.ext.javaVersion)
+ targetCompatibility = JavaVersion.toVersion(project.ext.javaVersion)
}
kotlinOptions {
- jvmTarget = JavaVersion.VERSION_17.majorVersion
+ jvmTarget = project.ext.javaVersion
}
externalNativeBuild {
diff --git a/modules/material-date-time-picker/src/main/java/com/wdullaer/materialdatetimepicker/date/DatePickerDialog.java b/modules/material-date-time-picker/src/main/java/com/wdullaer/materialdatetimepicker/date/DatePickerDialog.java
index 040822aa..ef97a974 100644
--- a/modules/material-date-time-picker/src/main/java/com/wdullaer/materialdatetimepicker/date/DatePickerDialog.java
+++ b/modules/material-date-time-picker/src/main/java/com/wdullaer/materialdatetimepicker/date/DatePickerDialog.java
@@ -415,7 +415,7 @@ public class DatePickerDialog extends AppCompatDialogFragment implements
notifyOnDateListener();
dismiss();
});
- okButton.setTypeface(ResourcesCompat.getFont(activity, R.font.robotomedium));
+ // okButton.setTypeface(ResourcesCompat.getFont(activity, R.font.robotomedium));
if (mOkString != null) okButton.setText(mOkString);
else okButton.setText(mOkResid);
@@ -424,7 +424,7 @@ public class DatePickerDialog extends AppCompatDialogFragment implements
tryVibrate();
if (getDialog() != null) getDialog().cancel();
});
- cancelButton.setTypeface(ResourcesCompat.getFont(activity, R.font.robotomedium));
+ // cancelButton.setTypeface(ResourcesCompat.getFont(activity, R.font.robotomedium));
if (mCancelString != null) cancelButton.setText(mCancelString);
else cancelButton.setText(mCancelResid);
cancelButton.setVisibility(isCancelable() ? View.VISIBLE : View.GONE);
diff --git a/modules/material-date-time-picker/src/main/java/com/wdullaer/materialdatetimepicker/time/TimePickerDialog.java b/modules/material-date-time-picker/src/main/java/com/wdullaer/materialdatetimepicker/time/TimePickerDialog.java
index 5648f691..7fc05ed7 100644
--- a/modules/material-date-time-picker/src/main/java/com/wdullaer/materialdatetimepicker/time/TimePickerDialog.java
+++ b/modules/material-date-time-picker/src/main/java/com/wdullaer/materialdatetimepicker/time/TimePickerDialog.java
@@ -791,7 +791,7 @@ public class TimePickerDialog extends AppCompatDialogFragment implements OnValue
dismiss();
});
mOkButton.setOnKeyListener(keyboardListener);
- mOkButton.setTypeface(ResourcesCompat.getFont(context, R.font.robotomedium));
+ // mOkButton.setTypeface(ResourcesCompat.getFont(context, R.font.robotomedium));
if (mOkString != null) mOkButton.setText(mOkString);
else mOkButton.setText(mOkResid);
@@ -800,7 +800,7 @@ public class TimePickerDialog extends AppCompatDialogFragment implements OnValue
tryVibrate();
if (getDialog() != null) getDialog().cancel();
});
- mCancelButton.setTypeface(ResourcesCompat.getFont(context, R.font.robotomedium));
+ // mCancelButton.setTypeface(ResourcesCompat.getFont(context, R.font.robotomedium));
if (mCancelString != null) mCancelButton.setText(mCancelString);
else mCancelButton.setText(mCancelResid);
mCancelButton.setVisibility(isCancelable() ? View.VISIBLE : View.GONE);
diff --git a/modules/material-date-time-picker/src/main/res/font/robotomedium.ttf b/modules/material-date-time-picker/src/main/res/font/robotomedium.ttf
deleted file mode 100644
index 39c63d74..00000000
Binary files a/modules/material-date-time-picker/src/main/res/font/robotomedium.ttf and /dev/null differ
diff --git a/settings.gradle.kts b/settings.gradle.kts
index f7f3775d..32e968e7 100644
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -17,6 +17,7 @@ private val libs = listOf(
"org.opencv-4.8.0",
"paddleocr",
"rapidocr",
+ "imagequant",
"jackpal.androidterm-1.0.70",
"jackpal.androidterm.emulatorview-1.0.42",
@@ -63,7 +64,7 @@ pluginManagement {
/* Unofficial. */
- "9.0" to "2.1.20",
+ "9.0" to "2.1.21", /* May 17, 2025. */
"8.14" to "2.1.10",
"8.13" to "2.1.10",
@@ -121,11 +122,11 @@ pluginManagement {
)
// @Reference https://developer.android.com/reference/tools/gradle-api
- // @Updated by SuperMonster003 on May 13, 2025.
+ // @Updated by SuperMonster003 on May 17, 2025.
val agpReleases: List = listOf(
"8.11.0-alpha10",
"8.10.0",
- "8.9.2",
+ "8.9.3", /* May 17, 2025. */
"8.8.2",
"8.7.3",
"8.6.1",
@@ -218,7 +219,7 @@ pluginManagement {
// @Updated by SuperMonster003 on May 13, 2025.
agpVersionMap = mapOf(
"2025.1" to "8.10.0", /* May 13, 2025. */
- "2024.3" to "8.9.2", /* Apr 11, 2025. */
+ "2024.3" to "8.9.3", /* May 17, 2025. */
"2024.2" to "8.7.3", /* Jan 13, 2025. */
"2024.1" to "8.5.2", /* Aug 30, 2024. */
"2023.3" to "8.4.2", /* Mar 28, 2024. */
@@ -230,7 +231,7 @@ pluginManagement {
),
// @Updated by SuperMonster003 on May 13, 2025.
kotlinVersionMap = mapOf(
- "2024.3" to "2.1.20", /* Apr 11, 2024. */
+ "2024.3" to "2.1.21", /* May 17, 2025. */
"2024.2" to "2.1.0", /* Nov 29, 2024. */
"2024.1" to "2.0.0", /* Aug 13, 2024. */
),
@@ -260,16 +261,7 @@ pluginManagement {
"D" to "Dolphin", /* Born on Jan 31, 2022. */
"C" to "Chipmunk", /* Born on Oct 13, 2021. */
"B" to "Bumblebee", /* Born on May 18, 2021. */
- "A" to "Arctic Fox",
- /* Born on Jan 26, 2021. */
-
- // @Hint by SuperMonster003 on Oct 18, 2023.
- // ! The codenames below were predicted but not official.
-
- "O" to "Ostrich", "P" to "Penguin", "Q" to "Quail",
- "R" to "Rhino", "S" to "Snail", "T" to "Tiger",
- "U" to "Unicorn", "V" to "Vicuna", "W" to "Walrus",
- "X" to "Xiphias", "Y" to "Yeti", "Z" to "Zebra",
+ "A" to "Arctic Fox", /* Born on Jan 26, 2021. */
),
) {
override val weight = Int.MAX_VALUE
@@ -288,7 +280,7 @@ pluginManagement {
name = "IntelliJIdea", vendor = "Jetbrains",
// @Updated by SuperMonster003 on Apr 23, 2025.
agpVersionMap = mapOf(
- "2025.1" to "8.9.2", /* Apr 23, 2025. */
+ "2025.1" to "8.9.3", /* May 17, 2025. */
"2024.3.1" to "8.7.3", /* Dec 10, 2024. */
"2024.3" to "8.7.0-rc01", /* Nov 15, 2024. */
"2024.2" to "8.5.2", /* Aug 13, 2024. */
@@ -299,7 +291,7 @@ pluginManagement {
),
// @Updated by SuperMonster003 on Apr 23, 2025.
kotlinVersionMap = mapOf(
- "2025.1" to "2.1.20", /* Apr 12, 2025. */
+ "2025.1" to "2.1.21", /* May 17, 2025. */
"2024.3.4" to "2.1.10", /* Feb 28, 2025. */
"2024.2.3" to "2.0.21", /* Oct 17, 2024. */
"2024.2" to "2.0.21-RC", /* Sep 27, 2024. */
@@ -377,8 +369,10 @@ pluginManagement {
// @Reference https://github.com/google/ksp/releases
// @Updated by SuperMonster003 on May 13, 2025.
val kspVersionMap = mapOf(
+ "2.2.0-RC" to "2.0.1", /* May 17, 2025. */
"2.2.0-Beta2" to "2.0.1", /* May 2, 2025. */
"2.2.0-Beta1" to "2.0.0", /* Apr 17, 2025. */
+ "2.1.21" to "2.0.1", /* May 17, 2025. */
"2.1.21-RC2" to "2.0.1", /* May 2, 2025. */
"2.1.21-RC" to "2.0.0", /* Apr 18, 2025. */
"2.1.20" to "2.0.1", /* May 1, 2025. */
diff --git a/version.properties b/version.properties
index 1aa79ad3..93eb8cba 100644
--- a/version.properties
+++ b/version.properties
@@ -1,6 +1,8 @@
-#Thu May 15 15:32:42 CST 2025
-BUILD_TIME=1747294362850
+#Sun May 18 11:47:57 CST 2025
+BUILD_TIME=1747540077602
COMPILE_SDK_VERSION=35
+IMAGE_QUANT_CMAKE_VERSION=3.22.1
+IMAGE_QUANT_NDK_VERSION=26.1.10909125
JAVA_VERSION=24
JAVA_VERSION_MIN_RADICAL=0
JAVA_VERSION_MIN_SUGGESTED=19
@@ -17,6 +19,6 @@ RAPID_OCR_OPENCV_MOBILE_LABEL_VERSION=13
RAPID_OCR_OPENCV_MOBILE_VERSION=4.5.3
TARGET_SDK_VERSION=35
TARGET_SDK_VERSION_INRT=29
-VERSION_BUILD=3223
-VERSION_NAME=6.6.3 Alpha4
+VERSION_BUILD=3233
+VERSION_NAME=6.6.3 Alpha5
VSCODE_EXT_REQUIRED_VERSION=1.0.8