Filter練習

/**
 * Copyright _wonder ( http://wonderfl.net/user/_wonder )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/aCWJ
 */

package {
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.filters.DropShadowFilter;
    
    public class Filter extends Sprite {
    	
    		private var filter:DropShadowFilter;
    		private var sprite:Sprite;
    		
        public function Filter() {
            init();
        }
        
        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(0,0,0,1,20,20,0.3);
        		
        		addEventListener(Event.ENTER_FRAME, onEnterFrame);
        }
        
        private function onEnterFrame(e: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]
        }
    }
}