Sets whether the gdk.GLContext should be forward compatible.
Forward compatibile 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.
The gdk.GLContext must not be realized or made current prior to calling
this function.
Sets whether the gdk.GLContext should be forward compatible.
Forward compatibile 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.
The gdk.GLContext must not be realized or made current prior to calling this function.