package
{
 import flash.display.Sprite;
 import flash.events.Event;
 import flash.display.StageScaleMode;
 import flash.display.StageAlign;

 public class animation_ch10_AngleBounceRotate extends Sprite
 {
  private var ball:animation_ch10_Ball;
  private var line:Sprite;
  private var gravity:Number = 0.3;
  private var bounce:Number = -0.6;
  
  public function animation_ch10_AngleBounceRotate()
  {
   init();
  }
 //@ init(s) 
  private function init():void
  {
   stage.scaleMode = StageScaleMode.NO_SCALE;
   stage.align = StageAlign.TOP_LEFT;
   ball = new animation_ch10_Ball();
   addChild(ball);
   ball.x = 100;
   ball.y = 100;
   
   line = new Sprite();
   line.graphics.lineStyle(1);
   line.graphics.lineTo(300, 0);
   addChild(line);
   line.x = 50;
   line.y = 200;
   line.rotation = 30;
   
   addEventListener(Event.ENTER_FRAME, onEnterFrame);
  }
 //@ frame(s) 
  private function onEnterFrame(event:Event):void
  {
   line.rotation = (stage.stageWidth/ 2 - mouseX) * .1;
   
   // normal motion code
   ball.vy += gravity;
   ball.x += ball.vx;
   ball.y += ball.vy;
   
   // get angle, sine and cosine
   var angle:Number = line.rotation * Math.PI / 180;
   var cos:Number = Math.cos(angle);
   var sin:Number = Math.sin(angle);
   
   // get position of ball, relative to line
   var x1:Number = ball.x - line.x;
   var y1:Number = ball.y - line.y;
   
   // rotate coordinates
   var y2:Number = cos * y1 - sin * x1;
   
   // perform bounce with rotated values
   if(y2 > -ball.height / 2)
   {
    // rotate coordinates
    var x2:Number = cos * x1 + sin * y1;
    
    // rotate velocity
    var vx1:Number = cos * ball.vx + sin * ball.vy;
    var vy1:Number = cos * ball.vy - sin * ball.vx;
   
    y2 = -ball.height / 2;
    vy1 *= bounce;
    
//@ rotate everything back;
    x1 = cos * x2 - sin * y2;
    y1 = cos * y2 + sin * x2;
    ball.vx = cos * vx1 - sin * vy1;
    ball.vy = cos * vy1 + sin * vx1;
    ball.x = line.x + x1;
    ball.y = line.y + y1;
   }
  }
 }
}