Allow bounds to be specified by convex hull of points for Leaner2D #466
Description
In some cases, the input area, where function to be interpolated is defined is not a rectangular one, and function is not defined outside of the definition area. It would be good, if one would be able to pass a convex hull of points instead (or just boundary points of the convex hull), which would allow more flexible definition of area, where points should be sampled.