[ActionScript 3.0] 创建倒影

 package
 {
     import flash.display.Bitmap;
     import flash.display.BitmapData;
     import flash.display.DisplayObject;
     import flash.display.GradientType;
     import flash.display.Loader;
     import flash.display.Shape;
     import flash.display.Sprite;
     import flash.events.Event;
     import flash.geom.Matrix;
     import flash.geom.Point;
     import flash.net.URLRequest;

     /**
       * ...
       * @author Frost.Yen
       */
     [SWF(width=800, height=1000, backgroundColor=0x000000, frameRate=30)]
     public class Reflection extends Sprite
     {
         private var ldr:Loader=new Loader();
         private var pic:Sprite=new Sprite();
         public function Reflection()
         {
             ldr.load(new URLRequest("http://hiphotos.baidu.com/frostyen/pic/item/7e49d8b53f6b48ffd9335aa2.jpg"));
             ldr.contentLoaderInfo.addEventListener(Event.COMPLETE, onImageLoaded);
         }

         private function onImageLoaded(e:Event):void
         {
             this.addChild(pic);
             pic.addChild(ldr);
             pic.x = 200;
             pic.y = 10;
             ldr.scaleX = ldr.scaleY = .5;
             createRef(pic,5,0);
         }
         /**
            *
            * @param obj  需创建倒影的对象
            * @param distance  对象与倒影的距离
            * @param offset  倒影的偏移量
            */
         private function createRef(obj:DisplayObject,distance:Number=5,offset:Number=0):void
         {
             // 倒置
             var bd:BitmapData = new BitmapData(obj.width,obj.height,true);
             var mtx:Matrix = new Matrix();
             mtx.d = -1;
             mtx.ty = bd.height;
             bd.draw(obj, mtx);

             // 添加倒影渐变
             var _width:int = bd.width;
             var _height:int = bd.height;

             mtx.createGradientBox(_width, _height, 0.5 * Math.PI,0,offset );
             var shape:Shape = new Shape();
             shape.graphics.beginGradientFill(GradientType.LINEAR, [0,0,0], [0.6,0.1, 0], [0,200, 255], mtx);
             shape.graphics.drawRect(0, 0, _width, _height);
             shape.graphics.endFill();
             var mask_bd:BitmapData = new BitmapData(_width,_height,true,0);
             mask_bd.draw(shape);
             // 生成最终效果
             bd.copyPixels(bd, bd.rect, new Point(0, 0), mask_bd, new Point(0, 0), false);
             // 将倒影放置于对象下方
             var ref:Bitmap = new Bitmap(bd);
             ref.y = obj.height + obj.y + distance;
             ref.x = obj.x;
             obj.parent.addChild(ref);
         }
     }

 }