package {
	import flash.display.*;
	import flash.events.*;
	import flash.geom.*;
	import flash.utils.*;

	public class Game extends Sprite {
		var backbufferBitmapData;
		var frontbufferBitmapData;

		var past;
		function tick() {
			var now = getTimer();
			var elapsedSeconds = (now - past)*0.001;
			past = now;
		}

		var pixels:Vector.<uint>;
		function render() {
			var i:uint = pixels.length; // declaring type here is a huge speedup
			while (i--) pixels[i] = 0xff000000 + Math.random() * 255;
			backbufferBitmapData.setVector(backbufferBitmapData.rect, pixels);
		}

		function flip() {
			frontbufferBitmapData.copyPixels(
				backbufferBitmapData,
				new Rectangle(0, 0, backbufferBitmapData.width, backbufferBitmapData.height),
				new Point(0, 0)
			);
		}

		function refresh(evt) {
			var start = getTimer();
			render();
			var renderTime = getTimer();
			tick();
			trace(renderTime - start, 'ms / render()', getTimer() - renderTime, 'ms / tick()');
			flip();
		}

		public function Game() {
			past = getTimer();
			backbufferBitmapData = new BitmapData(stage.stageWidth, stage.stageHeight);
			frontbufferBitmapData = backbufferBitmapData.clone();
			addChild(new Bitmap(frontbufferBitmapData));
			pixels = new Vector.<uint>(stage.stageWidth * stage.stageHeight, true);
			addEventListener(Event.ENTER_FRAME, refresh);
		}
	}
}