Flash技巧教程:as3把2D图片分析成文本文本功能

一篇在游戏开发中常用到的功能就是利用as3把2D图片分析成文本文本功能，下面我们来看看具体的操作过程与as实现代码吧。

对于一个像素的任意点，可以得到他的灰度。灰度计算公式

• getR(color) * 0.299 + getG(color) * 0.587 + getB(color) * 0.114; 
  
   

而每一个文字也有其对应的明暗，比如实心的一个球，就要比空心的显得更暗，因为它更加的紧密，求文字明暗的方法

private function getDensity(t:String):Number { 

            var ttf:TextField = new TextField; 

            ttf.autoSize = TextFieldAutoSize.LEFT; 

            ttf.text = t; 

  

 

            var bmd:BitmapData = new BitmapData(ttf.width, ttf.height, false, 0xffffff); 

            bmd.draw(ttf); 

            var c:int = 0; 

            for (var x:int = 0; x < bmd.width;x++ ) { 

                for (var y:int = 0; y < bmd.height;y++ ) { 

                    if (bmd.getPixel(x,y)!=0xffffff) { 

                        c++; 

                    } 

                } 

            } 

            return c / ttf.width / ttf.height; 

        }

完整代码

package

 

{ 

    import flash.display.Bitmap; 

    import flash.display.BitmapData; 

    import flash.display.Loader; 

    import flash.display.Sprite; 

    import flash.events.Event; 

    import flash.geom.Rectangle; 

    import flash.net.FileReference; 

    import flash.text.TextField; 

    import flash.text.TextFieldAutoSize; 

    import flash.text.TextFormat; 

    import sliz.miniui.Button; 

    import sliz.utils.UIUtils; 

    /** 

     * ... 

     * @author lizhi 

     */

 

    public class TestText extends Sprite 

    { 

        private var fonts:Array = []; 

        private var tf:TextField; 

  

 

        private var file:FileReference; 

        private var loader:Loader; 

        public function TestText() 

        { 

            tf = new TextField; 

            var tfm:TextFormat = new TextFormat; 

            tfm.size = 10; 

            tfm.leading = -2; 

            tf.defaultTextFormat = tfm; 

            tf.autoSize = TextFieldAutoSize.LEFT; 

            var text:String = " "; 

            var min:int = 32; 

            var max:int = 120; 

            while (++min < max) { 

                var c:String = String.fromCharCode(min); 

                text += c; 

            } 

            text += "           .'"*#@%+-)(TiI?><~"; 

            for (var i:int = 0; i < text.length;i++ ) { 

                c = text.charAt(i); 

                fonts.push({d:getDensity(c),t:c}); 

            } 

            fonts.sortOn("d", Array.NUMERIC|Array.DESCENDING); 

  

 

            //[Embed(source = '123.png')]var ic:Class; 

            //var bmd:BitmapData = (new ic as Bitmap).bitmapData; 

            //render(bmd); 

            addChild(tf); 

  

 

            UIUtils.changeStage(stage); 

  

 

            var explorer:Button = new Button("explorer image", 2, 20, this, browse); 

  

 

            loader = new Loader(); 

            loader.contentLoaderInfo.addEventListener(Event.COMPLETE, onLoad2); 

        } 

  

 

        private function render(bmd:BitmapData):void { 

            tf.width = 1000; 

            tf.height = 1000; 

            var x:int = 0; 

            var y:int = 0; 

            tf.text = ""; 

            while (y < bmd.height) { 

                while (x<bmd.width) { 

                    var gray:Number = getGray(bmd.getPixel(x, y)) / 0xff; 

                    var index:int = int((fonts.length - 1) * gray); 

                    tf.appendText(fonts[index].t); 

                    var r:Rectangle = tf.getCharBoundaries(tf.text.length - 1); 

                    x += r.width; 

                } 

                tf.appendText("n"); 

                y = r.bottom 

                x = 0; 

            } 

        } 

  

 

        private function getDensity(t:String):Number { 

            var ttf:TextField = new TextField; 

            ttf.autoSize = TextFieldAutoSize.LEFT; 

            ttf.text = t; 

  

 

            var bmd:BitmapData = new BitmapData(ttf.width, ttf.height, false, 0xffffff); 

            bmd.draw(ttf); 

            var c:int = 0; 

            for (var x:int = 0; x < bmd.width;x++ ) { 

                for (var y:int = 0; y < bmd.height;y++ ) { 

                    if (bmd.getPixel(x,y)!=0xffffff) { 

                        c++; 

                    } 

                } 

            } 

            return c / ttf.width / ttf.height; 

        } 

  

 

        private function getR(color:uint):uint { 

            return color << 8 >>> 24; 

        } 

        private function getG(color:uint):uint { 

            return color << 16 >>> 24; 

        } 

        private function getB(color:uint):uint { 

            return color << 24 >>> 24; 

        } 

        private function getGray(color:uint):uint { 

            return getR(color) * 0.299 + getG(color) * 0.587 + getB(color) * 0.114; 

        } 

  

 

        private function browse(e:Event):void { 

            file = new FileReference(); 

            file.browse(); 

            file.addEventListener(Event.SELECT, onSelect); 

        } 

  

 

        private function onSelect(e:Event):void { 

            file.load(); 

            file.addEventListener(Event.COMPLETE, onLoad); 

        } 

  

 

        private function onLoad(e:Event):void { 

  

 

            loader.loadBytes(file.data); 

  

 

        } 

  

 

        private function onLoad2(e:Event):void { 

            var content:Bitmap = loader.contentLoaderInfo.content as Bitmap; 

            render(content.bitmapData); 

        } 

    } 

  

 

}