the GtkWidget to be used as the rendering area.
a GdkGLConfig.
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 or GDK_GL_COLOR_INDEX_TYPE (currently not used).
TRUE if it is successful, FALSE otherwise.
Set the OpenGL-capability to the widget. This function prepares the widget for its use with OpenGL.