flash 与动画:发光

?????? 今天抽了点时间做了一个比较简单的实验，就是通过遮罩来实现一道光划过的效果。在flash 可以通过遮罩层来实现遮罩光效，简单实用，下面无聊写了一个比较简单的东西。实现简单的发光，不过，光效并不强烈，总是缺少一点什么。

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package 
{
	import flash.display.Sprite;
	import flash.display.DisplayObject;
	import flash.utils.Timer;
	import flash.events.TimerEvent;
	import flash.display.Bitmap;
	import flash.display.Shape;
	import flash.display.BitmapData;
	import flash.filters.GlowFilter;
	import flash.geom.ColorTransform;
	import flash.display.BlendMode;
	import flash.events.Event;
	import flash.geom.*;
	public class LightEffect
	{
		private var timer:Timer;
		private var glowShape:Shape;
		private var speed:Number;
		private var initSpeed:Number;
		private var maxLen:int;
		private var isFinish:Boolean = false;
		public  var a:Number = 0.12;
		private var bitmap:Bitmap;
                  public  var init_a:Number=0.12; 
		public function LightEffect(delay:Number,speed:Number)
		{

			timer = new Timer(delay);
			this.speed = speed;
			this.initSpeed = speed;
			timer.addEventListener(TimerEvent.TIMER,onTimer);
		}

		private function onTimer(event:TimerEvent):void
		{
			if (isFinish==false)
			{
				isFinish = true;
				glowShape.addEventListener(Event.ENTER_FRAME,onMoveGlow);
			}
		}

		private function onMoveGlow(event:Event):void
		{

			glowShape.x +=  speed;
			speed -=  a;
			if (glowShape.rotation != 0)
			{
				glowShape.y +=  speed;
				if (glowShape.x > maxLen + 20)
				{
					glowShape.x = 0;
					glowShape.y = 0;
					isFinish = false;
					a = init_a;
					speed = initSpeed;
					glowShape.removeEventListener(Event.ENTER_FRAME,onMoveGlow);
				}
			}
			else
			{
				if (glowShape.x > maxLen + 10)
				{
					glowShape.x =  -  glowShape.width;
					isFinish = false;
					a = init_a;
					speed = initSpeed;
					glowShape.removeEventListener(Event.ENTER_FRAME,onMoveGlow);
				}
			}

		}

		//设置发光对象
		public function setTargetGlow(displayObject:Sprite,rotation:Number,mask_W:Number=0,mask_H:Number=0):void
		{
			var container:Sprite=new Sprite();
			var copyBmp:BitmapData = new BitmapData(displayObject.width,displayObject.height,true,0x0);
			copyBmp.draw(displayObject);
			bitmap = new Bitmap(copyBmp);
			bitmap.blendMode = BlendMode.SCREEN;

			this.maxLen = bitmap.width;
			container.addChild(bitmap);

			glowShape=new Shape();
			glowShape.graphics.beginFill(0xffffff);

			if (rotation!=0)
			{
				glowShape.rotation = rotation;
				var w:Number = mask_W == 0 ? displayObject.width / 6:mask_W;
				var h:Number = mask_H == 0 ? displayObject.height:mask_H;
				glowShape.graphics.drawRect(-w/2,-h/2,w,h);
			}
			else
			{
				glowShape.graphics.drawRect(0,displayObject.width/4,displayObject.height);
			}

			glowShape.graphics.endFill();
			glowShape.cacheAsBitmap = true;
			bitmap.cacheAsBitmap = true;
			container.addChild(glowShape);
			bitmap.mask = glowShape;
			displayObject.addChild(container);
			timer.start();
		}

		//停止发光
		public function stopGlow():void
		{
			timer.stop();
		}

		//移除效果
		public function removeListener():void
		{
			timer.stop();
			glowShape.removeEventListener(Event.ENTER_FRAME,onMoveGlow);
			timer.removeEventListener(TimerEvent.TIMER,onTimer);
			timer = null;
		}
	}
}

//调用 即可,mc 为舞台设置的影片剪辑

var effect:LightEffect=new LightEffect(80,6);
effect.setTargetGlow(mc,45,mc.width/8,mc.height+30);

?由于设置一个减速的过程，可以修改这个程序让对加速度的值符合动画所需，当中会存在一个不完善的地方，例如遮罩后的光面，没想想象那么强烈，在实验的时候会存在这些疑惑.等等。