This class can find a concave shape that contains a set of points known as the concave hull.
It takes a set of points in a two dimensional plane and uses the concave hull algorithm to calculate the coordinates of the edges of a shape that contains all the points in the set. Specifically it's not a constrained delaunay algorithm.
Another class can render the points and the concave hull shape as an image file in the PNG format.
Sourcecode: