MARKUS

        /// move control point has same location of given pt along given delta

        /// </summary>

        /// <author>humkyung</author>

        /// <date>2019.06.20</date>

        /// <param name="pt"></param>

        /// <param name="dx"></param>

        /// <param name="dy"></param>

        public override void OnMoveCtrlPoint(Point pt, double dx, double dy)

        {

            Point selected = MathSet.getNearPoint((this as IPath).PointSet, pt);

            selected.X += dx;

            selected.Y += dy;

            for (int i = 0; i < (this as IPath).PointSet.Count; i++)

            {

                if (pt.Equals((this as IPath).PointSet[i]))

                {

                    (this as IPath).PointSet[i] = selected;

                    break;

                }

            }

            this.updateControl();

        }

        /// <summary>