マウスポインタに追随

/**
 * Copyright hacker_szoe51ih ( http://wonderfl.net/user/hacker_szoe51ih )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/9dqJ
 */

package {
    import flash.display.Sprite;
    import flash.events.*;
    public class Sqrt extends Sprite {
        
        public var maru:Sprite;
        public var pointLength:Number;
        public var nRadian:Number;
        
        public function Sqrt() {
            
            maru=new Sprite();
            maru.graphics.beginFill(0x33a8ff);
            maru.graphics.lineStyle();
            maru.graphics.drawCircle(0,0,20);
            maru.graphics.endFill();
            
            addChild(maru);
            maru.x=0;
            maru.y=0;
            
            
            stage.addEventListener(Event.ENTER_FRAME,enterFramer);
            
        }
        
        public function enterFramer(e:Event):void{
            
            var nx:int=mouseX;
            var ny:int=mouseY;
            nRadian=Math.atan2(ny-maru.y,nx-maru.x);
            pointLength=Math.sqrt(Math.pow(nx-maru.x,2)+Math.pow(ny-maru.y,2));
            maru.x+=pointLength*Math.cos(nRadian)*0.06;
            maru.y+=pointLength*Math.sin(nRadian)*0.06;
            
            
        }
        
        
    }
}