a #GdkGLDrawable.
the #GdkGLContext with which to share display lists and texture objects. NULL indicates that no sharing is to take place.
whether rendering is to be done with a direct connection to the graphics system.
GDK_GL_RGBA_TYPE.
Return: the new #GdkGLContext.
ConstructionException GTK+ fails to create the object.
Creates a new OpenGL rendering context.