/*
  second extension to try
  links to get started:

  http://cgit.freedesktop.org/xcb/proto/tree/src/glx.xml?id=HEAD
  http://cgit.freedesktop.org/mesa/mesa/tree/src/glx
  http://cgit.freedesktop.org/mesa/mesa/tree/src/glx/indirect.c

  http://www.opengl.org/wiki/Tutorial:_OpenGL_3.0_Context_Creation_(GLX)

*/