Gtk2 + openGL + Threads

[Andreas Volz <andreas brachttal net>]

Hello,

I've a problem that is related on gtk2, opengl and threads. But I think
the problem is gtk, so I'll ask the question on this list. Some time ago
I wrote an openGL application. Now, I want to include it in a gtk2 gui.
I don't want to use a gtk2 openGL-widget, because it must be able to run
without gtk2. This was a problem because there is a gtk_main-loop and a
glutMainLoop. So I used threads to solve this problem. But there are
still some problems.

If I do gtk_init() the openGL window is simply black. I could "work"
with the openGL-Display, but nothing is displayed. It works only if I
sleep for at least 1 sec. before gtk_init(). But if I reload the
openGL-Display it's simply black again.

I think this could be because gtk_init() loads another colortable as
openGl needs. What could I do to solve this problem? Should I better use
processes instead of threads?

int main (int argc, char **argv)
{
  GtkWidget *toolbox_window;
  GtkWidget *properties_window;  
  GThread *oglThread_id;

    /* glInterpret Thread */
  if (!g_thread_supported ()) g_thread_init (NULL);
  oglThread_id = g_thread_create (&oglThread, NULL, FALSE, NULL);

  sleep (1);
  
  gtk_init (&argc, &argv);

  add_pixmap_directory ("../pixmaps");
  
  toolbox_window = create_window_toolbox ();
  properties_window = create_window_properties ();
  
  gtk_widget_show (toolbox_window);
  gtk_widget_show (properties_window);

  gtk_main ();
  
  return 0;
}

Thanks
Andreas