package {
 import flash.display.*; 
 import flash.events.*;
 import flash.filters.*;

[SWF(width="400", height="400", backgroundColor="0xffffff", frameRate="8")]

/**
 * @author : Mateusz Malczak (http://segfaultlabs.com)
 */
 public class Main extends MovieClip {
   private var bg : BitmapData = new BitmapData(400,400);
   private var flies : Vector.<Fly> = new Vector.<Fly>(0,false);
   private var adja : ColorMatrixFilter;

public function Main():void
   {
     var i:int;
     var f:Fly;
     var b:Bitmap = new Bitmap( bg );
     addChild( b );
        for ( i=0; i<40; i+=1 )
        {
            f = new Fly();
            addChild( f );
            f.x = (350*Math.random()+25);
            f.y = (350*Math.random()+25);
            flies.push( f );
        };    
     adja = new ColorMatrixFilter([ 1,0,0,0,0,
                                    0,1,0,0,0,
                                    0,0,1,0,0,
                                    0,0,0,0.6,0 ] );
     addEventListener( Event.ENTER_FRAME, handleFlies );
   };

private function handleFlies( evt:Event ):void
   {
       bg.applyFilter( bg, bg.rect, bg.rect.topLeft, adja );
       flies.forEach( handler );

};

private function handler( obj:Fly, idx:int, v:Vector.<Fly> ):void
   {
      obj.handle();
      bg.draw( obj, obj.transform.matrix );
   };

}
}

import flash.display.Shape;
import flash.filters.*;
import flash.geom.*;
    
final class Fly extends Shape {

private static var maxT:Number = 30;
	private static var vMIN:Number = 30;
	private static var vMAX:Number = 90;
	private static var wallV:Number = 100;

private var t:Number;
	private var sp:Number;
	private var v:Point; 
	private var vb:Point;

private var nn:Number;
	private var alfa:Number;

public function Fly():void
	{
		vb = new Point();
		vb.x = 0; vb.y = 0;		
		v = new Point();
		v.x = 0; v.y = 0;
		alfa = 0; t = maxT*Math.random(); nn = 50;
		sp = (vMAX-vMIN)*Math.random()+vMIN;
		v.x = Math.random();
		v.y = Math.random();
		 if ( Math.random()<0.5 ) v.x = -v.x;
		 if ( Math.random()<0.5 ) v.y = -v.y;
		orient();

graphics.beginFill(0xab3a11);
                graphics.moveTo(0,0);
                graphics.lineTo(10,10);
                graphics.lineTo(-10,10);
                graphics.endFill();
                graphics.beginFill(0xab3a11);
                graphics.drawRect(-2,8,4,8);
                graphics.endFill();

filters = [ new BlurFilter(0,4), new GlowFilter() ];

}

public function randV():void
	{
		var vm:Number = vMAX-vMIN;
		sp = (vMAX-vMIN)*Math.random()+vMIN;;
		var x:Number = Math.random();
		var y:Number = Math.random();
		 if ( Math.random()<0.5 ) x = -x;
		 if ( Math.random()<0.5 ) y = -y;
		vb.x = v.x; 
		vb.y = v.y;
		vm = Math.sqrt( vb.x*vb.x + vb.y*vb.y );
		x  /= vm; y /= vm;
		v.x =  x * vb.x + y * vb.y; // ||  do v
		v.y = -x * vb.y + y * vb.x; // _|_ do v				
		alfa = Math.atan2( v.y, v.x ) / 20;
		v.x = vb.x; v.y = vb.y;
		orient();
		t = maxT+Math.random()*maxT; nn = 1;
		alpha = 0.20 + 0.80*Math.random();
	};
	
	public function orient():void
	{
		rotation = Math.atan2(v.y,v.x)*180/Math.PI+90;
	};
	
	public function handle():void
	{
		var vx:Number;
		var vy:Number;
		 if (nn<20)
		 {
			vx = Math.cos(alfa*nn);
			vy = Math.sin(alfa*nn);
			v.x =  vb.x*vx + vb.y*vy;
			v.y = -vb.x*vy + vb.y*vx;
			vy = sp/20*nn;
			vx = v.x*vy;
			vy = v.y*vy;
			orient();
			nn += 2;
		 } else {
				vx = v.x*sp;
				vy = v.y*sp;
			};
				
		t -= 1;
		 if ( t<0 ) randV();
		 if ( alpha<100 ) alpha += 0.2;

vx = vx - wallV/Math.sqrt(stage.stageWidth-1-x);
		vx = vx + wallV/Math.sqrt(x);

vy = vy - wallV/Math.sqrt(stage.stageHeight-1-y);
		vy = vy + wallV/Math.sqrt(y);

x += vx*0.1;		
		y += vy*0.1;

if ( x<0 || x>stage.stageWidth ) x = stage.stageWidth/2;
		 if ( y<0 || y>stage.stageHeight ) y = stage.stageHeight/2;		 		
	}

}

trapped