package
{
 import flash.display.Sprite;
 import flash.events.Event;
 import flash.filters.DropShadowFilter;
 
 public class animation_ch04_AnimatedFilters extends Sprite
 {
  private var filter:DropShadowFilter;
  private var sprite:Sprite;
  
  public function animation_ch04_AnimatedFilters()
  {
   init();
  }
 //@ init(s) 
  private function init():void
  {
   sprite = new Sprite();
   sprite.graphics.lineStyle(2);
   sprite.graphics.beginFill(0xffff00);
   sprite.graphics.drawRect(-50, -50, 100, 100);
   sprite.graphics.endFill();
   sprite.x = 200;
   sprite.y = 200;
   addChild(sprite);
   
   filter = new DropShadowFilter(0, 0, 0, 1, 20, 20, .3);
   
   addEventListener(Event.ENTER_FRAME, onEnterFrame);
  }
 //@ frane(s) 
  private function onEnterFrame(event:Event):void
  {
   var dx:Number = mouseX - sprite.x;
   var dy:Number = mouseY - sprite.y;
   
   filter.distance = -Math.sqrt(dx * dx + dy * dy) / 10;
   filter.angle = Math.atan2(dy, dx) * 180 / Math.PI;
   sprite.filters = [filter];
  }
 }
}