Concave polygon tesselator

Hi!
We need an idea(or code) of concave a polygon tesselator(only one simple polygon,but concave) without using GL functions at all.
Thanks in advance.

The Seidel algorithm can do that. Theres a link to source-code in

http://study.haifa.ac.il/~spirogov/graphics/Comp.graphics.algorithms.htm

Kilam.