Creates a new #GdkGLContext with the appropriate #GdkGLDrawable for this widget. The GL context must be freed when you're finished with it. See also gtk_widget_get_gl_context().
Returns the #GdkGLConfig referred by the @widget.
Returns the #GdkGLContext with the appropriate #GdkGLDrawable for this widget. Unlike the GL context returned by gtk_widget_create_gl_context(), this context is owned by the widget.
Returns the #GdkGLWindow owned by the @widget.
Returns whether the @widget is OpenGL-capable.
Set the OpenGL-capability to the @widget. This function prepares the widget for its use with OpenGL.