void R2::DrawClosedCurve(Array<Point>^ points, double tension)
This method draws a closed cardinal spline.
An array of points specifying the cardinal spline. The array must contain a minimum of three points.
A number that specifies how tightly the curve bends though the coordinates of the closed cardinal spline.
Each ending point is the starting point for the next cardinal spline.
Because the cardinal spline is closed, the curve continues through the last point and connects with the first point in the array.