As3.0中的位图(Bitmap/BitmapData)编程

As3.0中的位图(Bitmap/BitmapData)编程功能十分丰富，下面这些是官方文档上的基本示例：

1.位图使用(模糊)滤镜

//创建一个矩形区域的BitmapDatavar bmd:BitmapData = new BitmapData(80, 30, false, 0xefefef); //画个红色的矩形var rect:Rectangle = new Rectangle(20, 10, 40, 10);bmd.fillRect(rect, 0xFF0000); //找到红色矩形的右上顶点var pt:Point = new Point(rect.left, rect.top); //定义一个模糊滤镜var filter:BlurFilter = new BlurFilter(8,8,1); //应用滤镜bmd.applyFilter(bmd, rect, pt, filter); //创建一个位图对象，并加入到舞台var bm:Bitmap = new Bitmap(bmd); bm.scaleX = bm.scaleY = 2.0;bm.x = stage.stageWidth/2 -bm.width/2;bm.y = stage.stageHeight/2 - bm.height/2 ; addChild(bm);

2.像素拷贝及赋值

var bmd1:BitmapData = new BitmapData(90, 60, false, 0x00000000);var bmd2:BitmapData = bmd1.clone();//拷贝 //"画"一条白色的线for(var i:uint=10;i<=40;i++){    bmd1.setPixel32(i, i, 0xFFFFFFFF);} trace(bmd1.getPixel32(10, 10).toString(16)); // fffffffftrace(bmd2.getPixel32(10, 10).toString(16)); // ff000000 var bm1:Bitmap = new Bitmap(bmd1);this.addChild(bm1);bm1.x =bm1.y = 5; var bm2:Bitmap = new Bitmap(bmd2);bm2.x = 105;bm2.y =5;this.addChild(bm2);

3.颜色变换

var bmd:BitmapData = new BitmapData(80, 30, false, 0xFF0000); var cTransform:ColorTransform = new ColorTransform();cTransform.alphaMultiplier = 0.8;//设置透明度因子为0.8var rect:Rectangle = new Rectangle(0, 0, 40, 30);//定义左半边矩形区域bmd.colorTransform(rect, cTransform);//对rect区域应用colorTransform var bm:Bitmap = new Bitmap(bmd);addChild(bm); bm.x = stage.stageWidth/2 - bm.width/2;bm.y = stage.stageHeight/2 - bm.height/2;

4.比较位图差异

var bmd1:BitmapData = new BitmapData(50, 50, true, 0xFFFFAA00);var bmd2:BitmapData = new BitmapData(50, 50, true, 0xCCFFAA00);var diffBmpData:BitmapData = BitmapData(bmd1.compare(bmd2));var diffValue:String = diffBmpData.getPixel32(1, 1).toString(16);//解释：当二个位置尺寸大小相同，且仅alpha分量不同时，compare的值为 zzFFFFFF，其中zz为bmd1与bmd2的alpha分量差trace (diffValue); // 33ffffff var bm1:Bitmap = new Bitmap(bmd1);addChild(bm1);bm1.x = bm1.y = 5;var bm2:Bitmap = new Bitmap(bmd2);addChild(bm2);bm2.x = 60;bm2.y = 5; var bmDiff = new Bitmap(diffBmpData);addChild(bmDiff);bmDiff.x = 115;bmDiff.y = 5;

var bmd1:BitmapData = new BitmapData(50, 50, true, 0xFF00FF99);var bmd2:BitmapData = new BitmapData(50, 50, true, 0x99AA3366);var diffBmpData:BitmapData = BitmapData(bmd1.compare(bmd2));var diffValue:String = diffBmpData.getPixel32(1, 1).toString(16);//解释：当二个位置尺寸大小相同，但RGB分量不同时，compare的值为 FFxxyyzz，其中xx,yy,zz分别为bm1与bm2的RGB分量差，同时alpha分量差将被忽略trace (diffValue); // ff56cc33 var bm1:Bitmap = new Bitmap(bmd1);addChild(bm1);bm1.x = bm1.y = 5;var bm2:Bitmap = new Bitmap(bmd2);addChild(bm2);bm2.x = 60;bm2.y = 5; var bmDiff = new Bitmap(diffBmpData);addChild(bmDiff);bmDiff.x = 115;bmDiff.y = 5;

5.拷贝颜色通道

var bmd:BitmapData = new BitmapData(stage.stageWidth, stage.stageHeight, false, 0x00FF0000); var rect:Rectangle = new Rectangle(0, 0, 20, 40);var pt:Point = new Point(10, 10);bmd.copyChannel(bmd, rect, pt, BitmapDataChannel.RED, BitmapDataChannel.BLUE);//将红色通道复制到以(10,10)为顶点，宽为20,高为40的矩形区域的蓝色通道中 trace(bmd.getPixel32(10,10).toString(16));//ffff00ff，即矩形区域的最终颜色值为ff ff 00 ff(纯红 叠加 纯蓝) var bm:Bitmap = new Bitmap(bmd);this.addChild(bm);

6.截取位图的某一部分(像素)

var bmd1:BitmapData = new BitmapData(40, 40, false, 0x000000FF);var bmd2:BitmapData = new BitmapData(80, 40, false, 0x0000CC44); var rect:Rectangle = new Rectangle(0, 0, 20, 20);var pt:Point = new Point(10, 10);bmd2.copyPixels(bmd1, rect, pt);//将bmd1中以pt为左上顶点的rect矩形像素复制到bmd2中 var bm1:Bitmap = new Bitmap(bmd1);this.addChild(bm1);var bm2:Bitmap = new Bitmap(bmd2);this.addChild(bm2);bm2.x = 50;

7.将文本转换为位图

import flash.display.Bitmap;import flash.display.BitmapData;import flash.text.TextField; var tf:TextField = new TextField();tf.text = "bitmap text"; var myBitmapData:BitmapData = new BitmapData(80, 20);myBitmapData.draw(tf);var bmp:Bitmap = new Bitmap(myBitmapData);this.addChild(bmp);bmp.x = stage.stageWidth/2 - bmp.width/2;bmp.y = stage.stageHeight/2 - bmp.height/2;

8.仿PS中的颜色填充工具

//准备一个40*40绿色背景的BitmapDatavar myBitmapData:BitmapData = new BitmapData(40, 40, false, 0x0000FF00); //画二个有“交叉重叠”部分的“蓝色”矩形var rect:Rectangle = new Rectangle(0, 0, 25, 25);myBitmapData.fillRect(rect, 0x000000FF);rect = new Rectangle(20, 20, 20, 20);myBitmapData.fillRect(rect, 0x000000FF); //从坐标(10,10)开始寻找与(10,10)坐标(像素点相同且连续的区域)填充红色myBitmapData.floodFill(10, 10, 0x00FF0000); var bm:Bitmap = new Bitmap(myBitmapData);addChild(bm); bm.scaleX  = bm.scaleY = 3.0;bm.x = stage.stageWidth/2 - bm.width/2;bm.y = stage.stageHeight/2 - bm.height/2;

9.颜色融合

import flash.display.Bitmap;import flash.display.BitmapData;import flash.geom.Rectangle;import flash.geom.Point; var bmd1:BitmapData = new BitmapData(100, 80, true, 0xFF00FF00);var bmd2:BitmapData = new BitmapData(100, 80, true, 0xFFFF0000);var rect:Rectangle = new Rectangle(0, 0, 40, 40);var pt:Point = new Point(20, 20);var mult:uint = 0x80; // 50% ,各通道值均为128，即50%bmd1.merge(bmd2, rect, pt, mult, mult, mult, mult); var bm1:Bitmap = new Bitmap(bmd1);addChild(bm1);var bm2:Bitmap = new Bitmap(bmd2);addChild(bm2);bm2.x = 110; //最终值//new redDest = [(redSrc * redMultiplier) + (redDest * (256 - redMultiplier))] / 256;trace(bmd1.getPixel32(20,20).toString(16)); //ff7f7f00 //解释://返回值中Red分量为 7f = 0x00 * 0x80 + 0xff*(0x100-0x80)/0x100

10.噪点图

var bmd1:BitmapData = new BitmapData(80, 80);var bmd2:BitmapData = new BitmapData(80, 80); var seed:int = int(Math.random() * int.MAX_VALUE);bmd1.noise(seed, 0, 0xFF, BitmapDataChannel.RED, false);bmd2.noise(seed, 0, 0xFF, BitmapDataChannel.RED, true); var bm1:Bitmap = new Bitmap(bmd1);this.addChild(bm1);bm1.x = 10;bm1.y = 10;var bm2:Bitmap = new Bitmap(bmd2);this.addChild(bm2);bm2.x = 100;bm2.y = 10;  stage.addEventListener(Event.ENTER_FRAME,enterFrameHandler); function enterFrameHandler(e:Event):void{    seed = Math.floor(Math.random() * int.MAX_VALUE);    bmd1.noise(seed, 0, 0xFF, BitmapDataChannel.RED, false);    bmd2.noise(seed, 0, 0xFF, BitmapDataChannel.RED, true);    bm1.bitmapData = bmd1;    bm2.bitmapData = bmd2;}

11.另一种噪点图(有点类似卫星云图)

import flash.display.Bitmap;import flash.display.BitmapData; var bmd:BitmapData = new BitmapData(200, 200, false, 0x00CCCCCC); var seed:Number = Math.floor(Math.random() * 999999);var channels:uint = BitmapDataChannel.GREEN | BitmapDataChannel.BLUE;bmd.perlinNoise(100, 80, 6, seed, false, true, channels, false, null); var bm:Bitmap = new Bitmap(bmd);addChild(bm);bm.x = stage.stageWidth/2 - bm.width/2;bm.y = stage.stageHeight/2 - bm.height/2; stage.addEventListener(Event.ENTER_FRAME,enterFrameHandler); function enterFrameHandler(e:Event):void{    seed = Math.floor(Math.random() * 999999);    bmd.perlinNoise(100, 80, 6, seed, false, true, channels, false, null);    bm.bitmapData = bmd;    }

12.像素融解

import flash.display.BitmapData;import flash.display.Bitmap;import flash.geom.Point;import flash.geom.Rectangle;import flash.utils.Timer;import flash.events.TimerEvent; var rndColor:int = Math.random() * 0xffffffff;//随机背景色var fillColor:int = Math.random() * 0xffffffff;//随机填充色 var bmd:BitmapData = new BitmapData(100, 100, false, rndColor);var bitmap:Bitmap = new Bitmap(bmd);addChild(bitmap); bitmap.scaleX = bitmap.scaleY = 1.5;bitmap.x = stage.stageWidth/2 - bitmap.width/2;bitmap.y = stage.stageHeight/2 - bitmap.height/2; var tim:Timer = new Timer(20);tim.start();tim.addEventListener(TimerEvent.TIMER, timerHandler);  function timerHandler(event:TimerEvent):void {    var randomNum:Number = Math.floor(Math.random() * int.MAX_VALUE);    dissolve(randomNum);} function dissolve(randomNum:Number):void {    var rect:Rectangle = bmd.rect;    var pt:Point = new Point(0, 0);    var numberOfPixels:uint = 100;//每次融解100个像素        bmd.pixelDissolve(bmd, rect, pt, randomNum, numberOfPixels, fillColor);    var grayRegion:Rectangle = bmd.getColorBoundsRect(0xFFFFFFFF, rndColor, true);         if(grayRegion.width == 0 && grayRegion.height == 0 ) {        bmd.dispose();        rndColor = Math.random() * 0xffffffff;        fillColor = Math.random() * 0xffffff;        bmd = new BitmapData(100, 100, false, rndColor);        bitmap.bitmapData = bmd;                 //tim.stop();    }}

13.查找满足条件的颜色并替换

import flash.display.Bitmap;import flash.display.BitmapData;import flash.display.BitmapDataChannel;import flash.geom.Point;import flash.geom.Rectangle; var bmd1:BitmapData = new BitmapData(200, 200, true, 0xFFCCCCCC); var seed:int = int(Math.random() * int.MAX_VALUE);var channels:uint = BitmapDataChannel.RED | BitmapDataChannel.BLUE;bmd1.perlinNoise(100, 80, 12, seed, false, true, channels, false, null); var bitmap1:Bitmap = new Bitmap(bmd1);addChild(bitmap1); var bmd2:BitmapData = new BitmapData(200, 200, true, 0xFFCCCCCC);var pt:Point = new Point(0, 0);var rect:Rectangle = new Rectangle(0, 0, 200, 200);var threshold:uint =  0x00800000;//50%的红色通道值 var color:uint = 0x80FF0000;//替换后的颜色var maskColor:uint = 0x00FF0000;//因为只查找红色通道，所以遮罩仅为纯红色通道bmd2.threshold(bmd1, rect, pt, ">", threshold, color, maskColor, true); var bitmap2:Bitmap = new Bitmap(bmd2);bitmap2.x = bitmap1.x + bitmap1.width + 10;addChild(bitmap2); addEventListener(Event.ENTER_FRAME,EnterFrameHandler); function EnterFrameHandler(e:Event):void{    seed = int(Math.random() * int.MAX_VALUE);    bmd1.perlinNoise(100, 80, 12, seed, false, true, channels, false, null);    bitmap1.bitmapData = bmd1;    bmd2.threshold(bmd1, rect, pt, ">", threshold, color, maskColor, true);    bitmap2.bitmapData = bmd2;}

14.综合应用1：模仿MetaBall(当然这种方法并不精确)

var ballNum:uint=5;var balls:Array = new Array();var sW:Number=stage.stageWidth;var sH:Number=stage.stageHeight;var container:Sprite = new Sprite();var bmd:BitmapData=new BitmapData(sW,sH,false,0x00000000);var bitmap:Bitmap;var i:uint=0;var rect:Rectangle=new Rectangle(0,0,sW,sH);var pt:Point=new Point(0,0);var filter:BlurFilter=new BlurFilter(15,15); function init() {    for (i=0; i<ballNum; i++) {        var b:Ball=new Ball(30+Math.random()*40,0xffffff);        balls.push(b);        b.x = (sW - b.width)*Math.random() + b.radius;        b.y = (sH - b.width)*Math.random() + b.radius;        b.vx=(Math.random()*2-1)*2;        b.vy=(Math.random()*2-1)*2;        container.addChild(b);    }     bmd.draw(container);    bmd.applyFilter(bmd, rect, pt, filter);    bitmap=new Bitmap(bmd);    addChild(bitmap);    addEventListener(Event.ENTER_FRAME,enterFrameHandler);} function enterFrameHandler(e:Event):void {    for (i=0; i<ballNum; i++) {        var b:Ball=balls[i];        b.x+=b.vx;        b.y+=b.vy;        var adjust:uint=5;        if (b.x>=sW-b.radius-adjust) {            b.x=sW-b.radius-adjust;            b.vx*=-1;        } else if (b.x<b.radius+adjust) {            b.x=b.radius+adjust;            b.vx*=-1;        }         if (b.y>=sH-b.radius-adjust) {            b.y=sH-b.radius-adjust;            b.vy*=-1;        } else if (b.y<b.radius+adjust) {            b.y=b.radius+adjust;            b.vy*=-1;        }    }     bmd.dispose();    bmd=new BitmapData(sW,sH,false,0x00000000);    bmd.draw(container);    bmd.applyFilter(bmd, rect, pt, filter);    bitmap.bitmapData=bmd;} init();

15.综合应用2-粒子效果(从天地会淘来的)

package asbook{    import flash.display.*    import flash.geom.*    public class particleSample extends Sprite     {        private var apoint : Point;        private var aspeed : Number = 0;        private var arote  : Number = 0;        private var cpoint : Point;        private var rl : Number = 0;                 public function particleSample(cp:Point , lg:Number , art:Number , asp:Number):void        {// 1s            apoint = new Point();            cpoint = cp;            rl = lg;            arote = art;            aspeed = asp;            setapoint();        }// 1e                 public function pmove():Point         {// 2s            arote += aspeed;            if(arote >= 360) arote -= 360;            setapoint();            return apoint;        }// 2e                 public function setapoint():void        {// 3s            var temp:Number = arote * Math.PI / 180;            apoint.x = cpoint.x + rl * Math.cos(temp);            apoint.y = cpoint.y + rl * Math.sin(temp);                     }// 3e    }// class end}// package end

package asbook{    import flash.events.*;    import flash.display.*;    import flash.text.*;    import flash.utils.*;    public class FPSshow extends Sprite {        private var FPStxt:TextField;        private var FPScount:Number;        private var FPStimer:int;        private var fm:TextFormat;        public function FPSshow() {            fm = new TextFormat();            fm.size  = 20;            FPStxt = new TextField();            FPStxt.defaultTextFormat = fm;            FPScount = 0;            FPStxt.textColor = 0xFFFFFF;            FPStxt.x = 10;            FPStxt.y = 10;            addEventListener(Event.ADDED , onadd);            addEventListener(Event.REMOVED  , onremove);         }        private function onadd(evt:Event) {            stage.addEventListener(Event.ENTER_FRAME  , showFPS);            addChild(FPStxt);            FPStimer = getTimer();        }        private function onremove(evt:Event) {            stage.removeEventListener(Event.ENTER_FRAME , showFPS);        }        private function showFPS(evt:Event ) {            if ( getTimer() - 1000 > FPStimer ) {                FPStimer = getTimer();                FPStxt.text = "FPS : "+FPScount;                FPScount = 0;            } else {                FPScount++;            }        }     }//end class}//end package

package asbook{    import asbook.particleSample;    import asbook.FPSshow;    import flash.filters.*;    import flash.display.*;    import flash.geom.*;    import flash.events.*;         [SWF(height="300",width="300",frameRate=100)]    public class main extends MovieClip {        private var gNum1:int=1500;        private var gNum2:int=1500;        private var gArr:Array=[];        private var ccPoint:Point;        private var rrl:Number;        private var length1:Number=50;        private var length2:Number=200;        private var length3:Number=300;        private var bmp:Bitmap;        private var bmd:BitmapData;        private var bmdctf:ColorTransform=new ColorTransform(0.96,0.86,0);        private var stgw:Number=stage.stageWidth;        private var stgh:Number=stage.stageHeight;        private var started:Boolean=false;        private var bmped:Boolean=false;         public function main() {            ccPoint=new Point(stgw/2,stgh/2);            initbmp();            initstart();            addEventListener(Event.ENTER_FRAME , run);            addChild( new FPSshow()  );        }          private function initbmp():void {            if (bmped) {                return;            }            bmped=true;            bmd=new BitmapData(stgw,stgh,false,0);            bmp=new Bitmap(bmd);            addChild(bmp);        }         private function initstart():void {            if (started) {                return;            }            started=true;             for (var i:int  = 1; i <= gNum1; i++) {                rrl=Math.abs(Math.random()-Math.random());                var pp:particleSample = new particleSample(ccPoint , rrl * ( (length2 - length1)  / 2  *  1.2 )  + length1 / 2  , Math.random() * 360 , Math.random() * 10 - 6 );                gArr.push(pp);            }             for (i  = 1; i <= gNum2; i++) {                rrl=Math.abs(Math.random()-Math.random());                var pp:particleSample = new particleSample(ccPoint , rrl *  (length3 - length2) / 2      + length2 / 2  , Math.random() * 360 , Math.random() * 5 - 3 );                gArr.push(pp);            }            trace("Total:  " + gArr.length);        }        private function run(evt:Event):void {            bmd.lock();            bmd.colorTransform(bmd.rect , bmdctf);            bmd.applyFilter(bmd , bmd.rect , new Point() , new BlurFilter(10 , 10 ,1));            var pppoint:Point = new Point();            for (var i:int = 0; i <=( gArr.length - 1 ); i++) {                var pptemp:particleSample=gArr[i] as particleSample;                pppoint=pptemp.pmove();                bmd.setPixel32(pppoint.x , pppoint.y , 0xffffff);            }            bmd.unlock();        }    }// main class end}//package end