protected override List <PointF> GetPoints()
        {
            CubicBezier cb = new CubicBezier();

            cb.StartPoint = Start;
            cb.EndPoint   = End;

            cb.Control1 = control1;
            cb.Control2 = control2;

            cb.Resolution = 100;
            cb.CalculatePoints();

            List <PointF> ret = new List <PointF>();

            ret.AddRange(cb.Points);
            return(ret);
        }