/**
 * http://miniapp.org/blog/2009/05/04/106/
 * DisplacementMapFilterを使ってマウスの位置に移動させる
 * ステージサイズ100 * 100で作ってるので拡大して表示してます。
 */
package {
	
	import flash.display.Bitmap;
	import flash.display.BitmapData;
	import flash.display.BitmapDataChannel;
	import flash.display.Sprite;
	import flash.display.StageAlign;
	import flash.display.StageScaleMode;
	import flash.events.Event;
	import flash.filters.DisplacementMapFilter;
	import flash.filters.DisplacementMapFilterMode;
	import flash.geom.Point;
	import flash.geom.Rectangle;
	
	[SWF(backgroundColor="0xFFFFFF", width="100", height="100", frameRate="60")]
	public class Main5_7 extends Sprite {
		
		private static const WIDTH_STAGE:uint = 100;
		private static const HEIGHT_STAGE:uint = 100;
		
		public function Main5_7() {
			if (stage) init();
			else addEventListener(Event.ADDED_TO_STAGE, init);
		}
		
		private var _widthBox:uint = 20;
		private var _heightBox:uint = 20;
		private var _rect:Rectangle = new Rectangle(
			(WIDTH_STAGE - _widthBox) * Math.random(), //ランダムな場所に配置する
			(HEIGHT_STAGE - _heightBox) * Math.random(), 
			_widthBox,
			_heightBox
		);
		private var _canvas:Sprite = new Sprite();
		private var _mapBitmap:BitmapData = new BitmapData(WIDTH_STAGE, HEIGHT_STAGE, false);
		private var _dmf:DisplacementMapFilter = new DisplacementMapFilter(
			_mapBitmap,
			new Point(),
			BitmapDataChannel.BLUE,//x方向の移動に使う色
			BitmapDataChannel.GREEN,//y方向の移動に使う色
			WIDTH_STAGE * 2, //取り得るx値の最大 * 2
			HEIGHT_STAGE * 2, //取り得るy値の最大 * 2
			DisplacementMapFilterMode.COLOR
		);
		
		private function init(e:Event = null):void {
			removeEventListener(Event.ADDED_TO_STAGE, init);
			//stage.scaleMode = StageScaleMode.NO_SCALE;
			stage.align = StageAlign.TOP_LEFT;
			
			addChild(_canvas);
			//ランダムな場所に四角を描きます。
			var bmpd:BitmapData = new BitmapData(WIDTH_STAGE, HEIGHT_STAGE, false);
			bmpd.fillRect(_rect, 0x0);
			var bmp:Bitmap = new Bitmap(bmpd);
			_canvas.addChild(bmp);
			//trace(_rect.x, _rect.y);
			
			//trueで色と場所を確認
			if (false) { 
				//確認用
				addChild(new Bitmap(_mapBitmap));
				var sp:Sprite = new Sprite();
				sp.graphics.beginFill(0);
				sp.graphics.drawRect(_rect.x, _rect.y, _rect.width, _rect.height);
				addChild(sp);
			}
			
			addEventListener(Event.ENTER_FRAME, enterFrameHandler);
		}
		
		/**
		 * 
		 * @param	diff 動かしたい対象までの距離
		 * @param	scale 取り得る値の最大値
		 * @return
		 */
		private function getColor(diff:Number, scale:Number):uint {
			return Math.round((diff * 0x100) / scale) + 0x80;
		}
		
		private function enterFrameHandler(e:Event):void {
			_mapBitmap.lock();
			
			var diffX:Number = mouseX - _rect.x;
			var diffY:Number = mouseY - _rect.y;
			
			//目的地に色を塗る
			for (var yy:uint = 0; yy < HEIGHT_STAGE; ++yy) { 
				for (var xx:uint = 0; xx < WIDTH_STAGE; ++xx) { 
					var toX:Number = xx + diffX;
					var toY:Number = yy + diffY;
					
					var dx:Number = xx - toX;
					var dy:Number = yy - toY;
					
					var colorX:uint = getColor(dx, _dmf.scaleX);
					var colorY:uint = getColor(dy, _dmf.scaleY);
					
					var color:uint = colorY << 8 | colorX;
					_mapBitmap.setPixel(xx, yy, color);
				}
			}
			_mapBitmap.unlock();
			_canvas.filters = [_dmf];
		}
	}
}

DisplacementMapFilterのテスト