[GtkGLExt] from glut to gtkglext

[ivan danicic <ivand blueyonder co uk>]

Hello  All, I am trying to learn gtk..., so here is a really stupid question:
Is there an equivalent of glutdisplayfunc? Is there something like a display 
function? In my program I am trying to get it to re-display the window 
contents. Any comments gratefully received.
Ivan