package
{
 import flash.display.Sprite;
 import flash.display.StageAlign;
 import flash.display.StageScaleMode;
 import flash.events.Event;
 
 public class animation_ch06_Bouncing extends Sprite
 {
  private var ball:animation_ch05_Ball;
  private var vx:Number;
  private var vy:Number;
  
  public function animation_ch06_Bouncing()
  {
   init();
  }
 //@ init(s) 
  private function init():void
  {
   stage.scaleMode = StageScaleMode.NO_SCALE;
   stage.align=StageAlign.TOP_LEFT;

   ball = new animation_ch05_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);
  }
//@ frame(s)
  
  private function onEnterFrame(event:Event):void
  {
   ball.x += vx;
   ball.y += vy;
   var left:Number = 0;
   var right:Number = stage.stageWidth;
   var top:Number = 0;
   var bottom:Number = stage.stageHeight;
   
//@ bounce(s)
   if(ball.x + ball.radius > right)
   {
    ball.x = right - ball.radius;
    vx *= -1;
   }
   else if(ball.x - ball.radius < left)
   {
    ball.x = left + ball.radius;
    vx *= -1;
   }
   if(ball.y + ball.radius > bottom)
   {
    ball.y = bottom - ball.radius;
    vy *= -1;
   }
   else if(ball.y - ball.radius < top)
   {
    ball.y = top + ball.radius;
    vy *= -1;
   }
  }
 }
}