feat(canvas): 自由画布 - 增强空白起点、外观设置与节点连接体验 (#356)

web/src/lib/canvas/canvas-connected-node-placement.ts

@@ -0,0 +1,13 @@
+import type { Position } from "@/types/canvas";
+
+type NodeSize = {
+    width: number;
+    height: number;
+};
+
+export function connectedNodeCenterFromEdgeDrop(dropPosition: Position, nodeSize: NodeSize, handleType: "source" | "target"): Position {
+    return {
+        x: dropPosition.x + (handleType === "source" ? nodeSize.width / 2 : -nodeSize.width / 2),
+        y: dropPosition.y,
+    };
+}