System.Drawing.Graphics.MakeCurve C# (CSharp) Method

        void MakeCurve(PointF [] points, PointF [] tangents, int offset, int length, CurveType type)
        {
            MoveTo (points [offset].X, points [offset].Y);
            int i = offset;

            for (; i < offset + length; i++) {
                int j = i + 1;

                float x1 = points [i].X + tangents [i].X;
                float y1 = points [i].Y + tangents [i].Y;

                float x2 = points [j].X - tangents [j].X;
                float y2 = points [j].Y - tangents [j].Y;

                float x3 = points [j].X;
                float y3 = points [j].Y;

                context.AddCurveToPoint (x1, y1, x2, y2, x3, y3);
            }

            if (type == CurveType.Close) {
                /* complete (close) the curve using the first point */
                float x1 = points [i].X + tangents [i].X;
                float y1 = points [i].Y + tangents [i].Y;

                float x2 = points [0].X - tangents [0].X;
                float y2 = points [0].Y - tangents [0].Y;

                float x3 = points [0].X;
                float y3 = points [0].Y;

                context.AddCurveToPoint (x1, y1, x2, y2, x3, y3);

                context.ClosePath ();
            }
        }