forked from: flash on 2014-2-26

/**
 * Copyright s8t1h12akj ( http://wonderfl.net/user/s8t1h12akj )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/n5tB
 */

// forked from newaivirus's flash on 2014-2-26
package {

    import flash.display.Sprite;

    import flash.display.MovieClip;

    import flash.display.Bitmap;

    import flash.display.BitmapData;

    import flash.geom.Rectangle;

    import flash.events.Event;

    import flash.events.MouseEvent;

    import flash.text.TextField;

    import flash.text.TextFieldAutoSize;

    import flash.text.TextFormat;

    [SWF(width = "465", height = "465", backgroundColor = "0x000000", frameRate = "30")]



    public class ParticleText extends Sprite {

        private var canvas:BitmapData;

        private var textCanvas:BitmapData;

        private var _num:int = 0;

        private var maxDis:int = 400;

        

        // particles

        private var particleX:Array = new Array();

        private var particleY:Array = new Array();

        private var particleEx:Array = new Array();

        private var particleEy:Array = new Array();

        private var particleC:Array = new Array();

        

        public function ParticleText() {

            canvas = new BitmapData(

                stage.stageWidth,

                stage.stageHeight,

                false,

                0x000000

            );

            addChild(new Bitmap(canvas));

            

            var tf:TextField = new TextField();

            tf.defaultTextFormat = new TextFormat(

                "Times New Roman",

                60,

                0xFFFFFF

            );

            tf.autoSize = TextFieldAutoSize.LEFT;

            tf.text = "札幌も\n春の気配を\n感じます。\n\nAkijii";

            

            textCanvas = new BitmapData(

                tf.textWidth,

                tf.textHeight,

                false,

                0x000000

            );

            

            textCanvas.draw(tf);

            

            var ofx:Number = stage.stageWidth / 2 - textCanvas.width / 2;

            var ofy:Number = stage.stageHeight / 2 - textCanvas.height / 2;

            

            var num:Number = 0;

            var rad:Number;

            var dis:Number;



            for (var ex:Number = 0; ex < textCanvas.width; ex++) {

                for (var ey:Number = 0; ey < textCanvas.height; ey++) {

                    var c:uint = textCanvas.getPixel(ex, ey);

                    if (c != 0x000000) {

                        particleEx[num] = ex + ofx;

                        particleEy[num] = ey + ofy;

                        particleC[num] = c;

                        rad = Math.random() * (Math.PI * 2);

                        dis = Math.random() * maxDis;

                        particleX[num] = ex + dis * Math.cos(rad);

                        particleY[num] = ex + dis * Math.sin(rad);

                        num++;

                    }

                }

            }



            stage.addEventListener(Event.ENTER_FRAME, onEnterframe);

        }



        private function onEnterframe( evt:Event ):void {

            canvas.lock();

            canvas.fillRect(canvas.rect, 0x000000);

            for(var i:int = 0; i < _num; i++) {

                if(Math.abs(particleEx[i] - particleX[i]) < 0.5 &&

                     Math.abs(particleEy[i] - particleY[i]) < 0.5) {

                    particleX[i] = particleEx[i];

                    particleY[i] = particleEy[i];

                } else {

                    particleX[i] += (particleEx[i] - particleX[i]) * 0.1;

                    particleY[i] += (particleEy[i] - particleY[i]) * 0.1;

                }

                canvas.setPixel(particleX[i], particleY[i], particleC[i]);

            }

            

            var n:int = particleX.length;

            

            _num = (_num + 30 < n) ? _num + 30 : particleX.length;

            canvas.unlock();

        }

    }

}