a GtkWidget.
the GdkGLContext with which to share display lists and texture objects. NULL indicates that no sharing is to take place. [allow-none]
whether rendering is to be done with a direct connection to the graphics system.
GDK_GL_RGBA_TYPE.
the new GdkGLContext.
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().