Create jagged or smooth shapes from the same array of points.
SKShape object can be initialized with an array of points describing a path. The
init(spline method can smoothly interpolate between these points to create a curve rather than the series of straight lines created by
init(points:. The following code shows how to create two shape nodes using the same array of points for both initializers.
The following image shows
linear in blue and
spline in red.