GLX_MESA_set_3dfx_mode
http://oss.sgi.com/projects/ogl-sample/registry/MESA/set_3dfx_mode.txt
GLX_3DFX_WINDOW_MODE_MESA 0x1
GLX_3DFX_FULLSCREEN_MODE_MESA 0x2
GLboolean glXSet3DfxModeMESA (GLint mode)