package
{
	import flash.display.Sprite;
	import flash.display.StageAlign;
	import flash.display.StageScaleMode;
	import flash.events.Event;
	
	public class animation_ch06_Friction2 extends Sprite
	{
		private var ball:animation_ch06_Ball;
		private var vx:Number = 0;
		private var vy:Number = 0;
		private var friction:Number = 0.9;
		
		public function animation_ch06_Friction2()
		{
			init();
		}
		
		private function init():void
		{
			stage.scaleMode = StageScaleMode.NO_SCALE;
			stage.align=StageAlign.TOP_LEFT;

			ball = new animation_ch06_Ball();
			ball.x = stage.stageWidth / 2;
			ball.y = stage.stageHeight / 2;
			vx = Math.random() * 10 - 5;
			vy = Math.random() * 10 - 5;
			addChild(ball);
			addEventListener(Event.ENTER_FRAME, onEnterFrame);
		}
		
		private function onEnterFrame(event:Event):void
		{
			vx *= friction;
			vy *= friction;
			ball.x += vx;
			ball.y += vy;
		}
	}
}