void gdk_gl_context_set_forward_compatible ( GdkGLContext* context, gboolean compatible )
Sets whether the
GdkGLContext should be forward-compatible.
Forward-compatible contexts must not support OpenGL functionality that has been marked as deprecated in the requested version; non-forward compatible contexts, on the other hand, must support both deprecated and non deprecated functionality.
GdkGLContext must not be realized or made current prior to calling