α = Math.atan((_parent._x-this._x-_root.ball._x)/(_parent._y-_root.ball._y-this._y));
               sinα = Math.sin(α);
               cosα = Math.cos(α);
               sin2α = Math.pow(sinα, 2);
               cos2α = Math.pow(cosα, 2);
               xspeed = xspeed*(f*cos2α-e*sin2α)+yspeed*sinα*cosα*(f+e);
               yspeed = xspeed*sinα*cosα*(f+e)+yspeed*(f*sin2α-e*cos2α);