package {
          import flash.display.Sprite;
          import flash.display.StageAlign;
          import flash.display.StageScaleMode;
          import flash.events.Event;
          import flash.geom.Point;
  
          public class @ax-animation-ch14-Cosines extends Sprite
          {
                  private var segment0:animation_ch14_Segment;
                  private var segment1:animation_ch14_Segment;
                  
                  public function @ax-animation-ch14-Cosines()
                  {
                          init();
                  }
                  
                  private function init():void
                  {
                          stage.align = StageAlign.TOP_LEFT;
                          stage.scaleMode = StageScaleMode.NO_SCALE;
                          segment0 = new animation_ch14_Segment(100, 20);
                          addChild(segment0);
                          
                          segment1 = new animation_ch14_Segment(100, 20);
                          addChild(segment1);
                          segment1.x = stage.stageWidth / 2;
                          segment1.y = stage.stageHeight / 2;
                          
                          addEventListener(Event.ENTER_FRAME, onEnterFrame);
                  }
                  
                  private function onEnterFrame(event:Event):void
                  {
                          var dx:Number = mouseX - segment1.x;
                          var dy:Number = mouseY - segment1.y;
                          var dist:Number = Math.sqrt(dx * dx + dy * dy);
                          
                          var a:Number = 100;
                          var b:Number = 100;
                          var c:Number = Math.min(dist, a + b);
                          
                          var B:Number = Math.acos((b * b - a * a - c * c) / (-2 * a * c));
                          var C:Number = Math.acos((c * c - a * a - b * b) / (-2 * a * b));
                          var D:Number = Math.atan2(dy, dx);
                          var E:Number = D + B + Math.PI + C;
                          
                          segment1.rotation = (D + B) * 180 / Math.PI;
                          
                          segment0.x = segment1.getPin().x;
                          segment0.y = segment1.getPin().y;
                          segment0.rotation = E * 180 / Math.PI;
                  }
          }
  }