perf: 优化

assets/scripts/Shadow2D.ts

@@ -0,0 +1,52 @@
+import { _decorator, Component, Node, Graphics, Color, UITransform } from 'cc';
+const { ccclass, property } = _decorator;
+
+@ccclass('Shadow2D')
+export class Shadow2D extends Component {
+
+  @property(Node)
+  target: Node | null = null;   // 角色节点
+
+  @property
+  shadowWidth: number = 60;
+
+  @property
+  shadowHeight: number = 20;
+
+  @property
+  shadowAlpha: number = 80; // 0-255
+
+  private shadowNode: Node | null = null;
+
+  start() {
+    if (!this.target) {
+      console.warn("Shadow2D: 未绑定角色节点 target");
+      return;
+    }
+
+    // 创建影子节点
+    this.shadowNode = new Node("Shadow");
+    let g = this.shadowNode.addComponent(Graphics);
+    this.target.addChild(this.shadowNode);
+
+    // 调整大小
+    let ui = this.shadowNode.addComponent(UITransform);
+    ui.setContentSize(this.shadowWidth, this.shadowHeight);
+
+    // 画椭圆
+    g.fillColor = new Color(0, 0, 0, this.shadowAlpha);
+    g.ellipse(0, 0, this.shadowWidth / 2, this.shadowHeight / 2);
+    g.fill();
+
+    // 放到角色脚下
+    this.shadowNode.setPosition(0, -this.target.getComponent(UITransform).height / 2);
+  }
+
+  update(dt: number) {
+    if (!this.shadowNode || !this.target) return;
+
+    // 始终保持在角色底部（比如角色动画高度变化时也能跟随）
+    let ui = this.target.getComponent(UITransform);
+    this.shadowNode.setPosition(0, -ui.height / 2);
+  }
+}