The TriangleFanArray object draws an array of vertices as a set of
connected triangle fans. An array of per-strip
vertex counts specifies where the separate strips (fans) appear
in the vertex array. For every strip in the set,
each vertex, beginning with the third vertex in the array,
defines a triangle to be drawn using the current vertex,
the previous vertex and the first vertex. This can be thought of
as a collection of convex polygons.
