forked from: flash on 2010-4-14

/**
 * Copyright bradsedito ( http://wonderfl.net/user/bradsedito )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/6OCj
 */





package
{
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.events.KeyboardEvent;
    import flash.geom.Point;

 
    public class Main extends Sprite
    {
        private var vp:Point = new Point(stage.stageWidth / 2, stage.stageHeight / 2);
        private var data:Array = new Array();
        private var camera:Camera = new Camera();
        private var radian:Number = 0.01;

 
        public function Main()
        {
            for (var i:int = 0; i < 50; i++)
            {
                var ball:Ball = new Ball();
                ball.px = Math.random() * 300 - 150;
                ball.py = Math.random() * 300 - 150;
                ball.pz = Math.random() * 300;
                addChild(ball);
 
                data.push(ball);
            }
 
            stage.addEventListener(KeyboardEvent.KEY_DOWN, onKeyDown);
            addEventListener(Event.ENTER_FRAME, onEnterFrame);
        }

 
        private function onEnterFrame(event:Event):void
        {
            data.sortOn("pz", Array.NUMERIC | Array.DESCENDING);
 
            for (var i:int = 0; i < data.length; i++)
            {
                var ball:Ball = data[i];
                addChild(ball);
 
                var cos:Number = Math.cos(radian);
                var sin:Number = Math.sin(radian);
 
                var tempX:Number = ball.px * cos - ball.py * sin;
                var tempY:Number = ball.px * sin + ball.py * cos;
 
                ball.px = tempX;
                ball.py = tempY;
 
                var scale:Number = camera.getScale(ball.pz);
                ball.scaleX = ball.scaleY = scale;
 
                if (ball.pz > camera.z - camera.f)
                {
                    ball.x = vp.x + (ball.px - camera.x) * scale;
                    ball.y = vp.y + (ball.py - camera.y) * scale;
                    ball.visible = true;
                }
                else
                {
                    ball.visible = false;
                }
            }
        }
 
        private function onKeyDown(event:KeyboardEvent):void 
        {
            if (event.keyCode == 37) camera.x -= 10;
            if (event.keyCode == 39) camera.x += 10;
            if (event.keyCode == 38) camera.y -= 10;
            if (event.keyCode == 40) camera.y += 10;
 
            if (event.keyCode == 83) camera.z -= 10;
            if (event.keyCode == 87) camera.z += 10;
        }
    }
}
 
 
import flash.display.Sprite;
 
class Ball extends Sprite
{
    public var px:Number = 0;
    public var py:Number = 0;
    public var pz:Number = 0;
 
    public function Ball()
    {
        graphics.beginFill(int.MAX_VALUE * Math.random());
        graphics.drawCircle(0, 0, 10);
        graphics.endFill();
    }
}


 
class Camera
{
    public var x:Number = 0;
    public var y:Number = 0;
    public var z:Number = 0;
    public var f:Number = 200;
 
    public function getScale(objZ:Number):Number
    {
        var scale:Number = f / (f + objZ - z);
        return (scale < 0) ? 0 : scale;
    }
}