feat: 增加轨迹

src/editor/canvas/sceneTransform.test.ts

@@ -0,0 +1,49 @@
+import { expect, it } from "vitest";
+import type { SceneSettings } from "../schema/directorProject";
+import { getSceneGroupTransform } from "./sceneTransform";
+
+function createScene(patch: Partial<SceneSettings> = {}): SceneSettings {
+  return {
+    scale: 1,
+    position: [0, 0, 0],
+    rotation: [0, 0, 0],
+    backgroundColor: "#000000",
+    panoramaYaw: 0,
+    panoramaRadius: 60,
+    showLabels: true,
+    snapToGrid: false,
+    showGround: true,
+    groundOpacity: 0.4,
+    groundHeight: 0,
+    ...patch,
+  };
+}
+
+it("maps the scene scale onto all three axes", () => {
+  expect(getSceneGroupTransform(createScene({ scale: 2.5 }))).toEqual({
+    position: [0, 0, 0],
+    rotation: [0, 0, 0],
+    scale: [2.5, 2.5, 2.5],
+  });
+});
+
+it("passes the scene position and rotation through unchanged", () => {
+  expect(getSceneGroupTransform(createScene({ position: [1, 3, -2], rotation: [0, 0.5, 0] }))).toEqual({
+    position: [1, 3, -2],
+    rotation: [0, 0.5, 0],
+    scale: [1, 1, 1],
+  });
+});
+
+it("keeps the ground plane and the viewport grid on the same world height", () => {
+  const scene = createScene({ scale: 1.5, position: [0, 2, 0], groundHeight: 1.2 });
+  const transform = getSceneGroupTransform(scene);
+  const gridElevation = 0.002;
+
+  // 地面：局部 y = groundHeight；网格：局部 y = groundHeight + 抬升
+  // 两者共用同一个场景组 → 世界高度只差 抬升 × 场景缩放，永远不会分叉成两层地面
+  const groundWorldY = transform.position[1] + scene.groundHeight * transform.scale[1];
+  const gridWorldY = transform.position[1] + (scene.groundHeight + gridElevation) * transform.scale[1];
+
+  expect(gridWorldY - groundWorldY).toBeCloseTo(gridElevation * scene.scale, 6);
+});