topical media & game development
[] readme course(s) preface I 1 2 II 3 4 III 5 6 7 IV 8 9 10 V 11 12 afterthought(s) appendix reference(s) example(s) resource(s) _

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animation-ch10-AngleBounceRotate.ax

animation-ch10-AngleBounceRotate.ax [swf] [flash] flex 


  package
  {
   import flash.display.Sprite;
   import flash.events.Event;
   import flash.display.StageScaleMode;
   import flash.display.StageAlign;
  
   public class @ax-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 @ax-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;
     }
    }
   }
  }
[] readme course(s) preface I 1 2 II 3 4 III 5 6 7 IV 8 9 10 V 11 12 afterthought(s) appendix reference(s) example(s) resource(s) _

(C) Æliens 04/09/2009

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