> gluTessCallback(self._tesselator, GLU_TESS_BEGIN_DATA, > <void(*)()>&tesselator_begin) <<<<<<<<<<<<<<<<<<< Hi, I use GLU callback as following : gluTessCallback(self._tess_obj, GLU_TESS_VERTEX_DATA, <_GLUfuncptr> vertex_glu_callback) _GLUfuncptr is a dummy C type which is defined in glu.h i believe ; using it is the recommanded way for GLU. Jiba