flash on 2011-6-22

/**
 * Copyright yama3 ( http://wonderfl.net/user/yama3 )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/87g4
 */

package {
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.events.MouseEvent;
    
    import flash.display.Bitmap;
    import flash.display.BitmapData;
    
    import flash.geom.Point;
    
    [SWF(width="465", height="465", frameRate="60")]
    
    public class FlashTest extends Sprite {
        public static const WIDTH:int = 465;
        public static const HEIGHT:int = 465;
        
        private var particles:/*Particle*/Array;
        private var particleNum:int;
        private var canvas:BitmapData;
        
        private var press:Boolean = false;
        private static const POWER_RANGE:Number = 150;
        
        public function FlashTest() {
            if(stage) init();
            else addEventListener(Event.ADDED_TO_STAGE, init);            
        }
        
        private function init(e:Event = null):void
        {
            removeEventListener(Event.ADDED_TO_STAGE, init);
            graphics.beginFill(0);
            graphics.drawRect(0, 0, WIDTH, HEIGHT);
            graphics.endFill();
            
            particles = [];
            particleNum = 0;
            for(var y:int = 0; y < (HEIGHT / 3); y++)
            {
                for(var x:int = 0; x < (WIDTH / 3); x++)
                {
                    var p:Particle = new Particle();
                    p.x = x * 3;
                    p.y = y * 3;
                    p.basex = p.x;
                    p.basey = p.y;
                    
                    particles.push(p);
                    particleNum++;
                }
            }
            
            canvas = new BitmapData(WIDTH, HEIGHT, true, 0);
            addChild(new Bitmap(canvas));
            
            addEventListener(Event.ENTER_FRAME, EnterFrameHandler);
            stage.addEventListener(MouseEvent.MOUSE_DOWN, MouseDownHandler);
            stage.addEventListener(MouseEvent.MOUSE_UP, MouseUpHandler);
        }
        
        private function EnterFrameHandler(e:Event):void
        {
            var i:int;
            
            if(press)
            {
                var mx:Number = stage.mouseX;
                var my:Number = stage.mouseY;
                
                var powerRange:Number = POWER_RANGE * POWER_RANGE;
                
                for(i = 0; i < particleNum; i++)
                {
                    var disx:Number = particles[i].x - mx;
                    var disy:Number = particles[i].y - my;
                    var dislength:Number = (disx * disx) + (disy * disy);
                    var prevx:Number = particles[i].x;
                    var prevy:Number = particles[i].y;
                    
                    if(dislength <= powerRange)
                    {
                        var power:Number = (1 - (dislength / powerRange)) * 10;
                        var rad:Number = power * Math.PI / 180;
                        var cos:Number = Math.cos(rad);
                        var sin:Number = Math.sin(rad);
                        var newx:Number = mx + (disx * cos - disy * sin) * 0.9;
                        var newy:Number = my + (disx * sin + disy * cos) * 0.9;
                        
                        particles[i].x = newx;
                        particles[i].y = newy;                        
                    }
                }
            } else {
                for(i = 0; i < particleNum; i++)
                {
                    particles[i].x += particles[i].exx;
                    particles[i].y += particles[i].exy;
                    particles[i].exx *= 0.9;
                    particles[i].exy *= 0.9;
                    
                    particles[i].x += (particles[i].basex - particles[i].x) * 0.2;
                    particles[i].y += (particles[i].basey - particles[i].y) * 0.2;
                    
                    if(Math.abs((particles[i].basex - particles[i].x) * (particles[i].basex - particles[i].x) + (particles[i].basey - particles[i].y) * (particles[i].basey - particles[i].y)) >0.1) {
                        particles[i].x = particles[i].basex;
                        particles[i].y = particles[i].basey;
                    }
                }
            }
            canvas.lock();
            canvas.fillRect(canvas.rect, 0);
            for(i = 0; i<particleNum; i++)
            {
                canvas.setPixel32(particles[i].x, particles[i].y, 0xffffffff);
            }
            canvas.unlock();
        }
        
        private function MouseDownHandler(e:MouseEvent):void
        {
            press = true;
        }
        
        private function MouseUpHandler(e:MouseEvent):void
        {
            press = false;
            var mx:Number = stage.mouseX;
            var my:Number = stage.mouseY;
            
            for(var i:int = 0; i<particleNum; i++)
            {
                var distance:Number = Math.sqrt((particles[i].x - mx) * (particles[i].x - mx) + (particles[i].y - my) * (particles[i].y - my));
                
                if(distance > 200)
                {
                    particles[i].exx = 0;
                    particles[i].exy = 0;
                } else {
                    particles[i].exx = (particles[i].x - mx) / distance * (1 - (distance / 200)) * 100;
                    particles[i].exy = (particles[i].y - my) / distance * (1 - (distance / 200)) * 100;
                }
            }
        }
    }
}

class Particle {
    public var x:Number;
    public var y:Number;
    public var basex:Number;
    public var basey:Number;
    public var compressCount:int = 0;
    public var explosionAngle:Number;
    
    public var vx:Number = 0;
    public var vy:Number = 0;
    
    public var exx:Number = 0;
    public var exy:Number = 0;
}