I wrote my Diploma-thesis about "Geometrische Algorithmen in Haskell" (Geometric Algorithms in Haskell). I also wrote a library for these geometric algorithms.
I once worked on an Interface for OpenGL (using HOpenGL) to visualize input and output of the geometric algorithms. But i stopped it a long time ago due to time constraints. See for example some triangulations of polygons in the following picture.
I worked on internals of the library, too. For example, the next release (if it is ever released) will use multiparameter type classes and some of the GHC libraries.
