+extern void (*gfx_zbuffer)(bool enable);
+extern void (*gfx_cull_face)(Gfx_cull_face cf);
+extern void (*gfx_reshape)(int width, int height);
+extern void (*gfx_wireframe)(bool enable);
+extern void (*gfx_swapbuffers)();
+extern void (*gfx_begin_drawing)();
+extern void (*gfx_end_drawing)();