[GtkGLExt] [Repost] Re: GdkGLPixmap troubles

[Jose Commins <axora axora net>]

   Lindley, I think I've just spotted what the problem may be.  In your 
code you have this:

gboolean reshapeGL(GtkWidget *widget, GdkEventConfigure *evnt, gpointer 
data)
{
GUIWindow* me = (GUIWindow*)data;

   There's a quirk in using the 'gpointer data' object in a GTK 
function - it actually gets swapped in the stack if you do so, and is 
*not recommended* :P.
   The best approach is to not use the 'gpointer data' at all; instead, 
if you want to pass your user data to a GTK function, attach a GObject 
to it like so - in this example I am attaching it to the window 
containing the GL context:

   (-in place of setting the user data in your initialisation code-)
   g_object_set_data ((GObject *)theWindowWithYourGLContext, 
"myUserData", &theActualData);

   And then use something like this to retrieve it:

gboolean reshapeGL(GtkWidget *widget, GdkEventConfigure *evnt, gpointer 
data)
{
   GUIWindow* me = g_object_get_data ((GObject 
*)gtk_widget_get_toplevel (widget), "myUserData")));

   In your reshape (and other) functions that need it.

Regards,
       Jose.