Re: [GtkGLExt] Sharing display lists among a dynamic set of widgets

["Timothy M. Shead" <tshead k-3d com>]

Dave Andruczyk wrote:
> --- "Timothy M. Shead" <tshead k-3d com> wrote:
>
>
> > My application (http://k3d.sourceforge.net) provides users with 
> > zero-to-many OpenGL views of a 3D scene, with users able to create and 
> > destroy views at-will.  We also need to share display lists between 
> > views for efficiency.  The problem is that if the "first" view (the one 
> > which is passed to subsequent views as the "share_list" argument) is 
> > destroyed, all the display lists go with it.  I'm wondering if there is 
> > any way around this, besides creating a hidden widget with a 
> > GdkGLContext that never gets destroyed?  Could the reference count of 
> > the "first" GdkGLContext be managed to prevent its destruction?
>
>
> You answered it at the end.  Just increment it's reference count for each
> additional view (decrement the refcount when the view is destroyed )and it
> won't get destroyed until the refcount is zero.

Unfortunately the reference counting just isn't working for me - after 
digging into the source, I see that the share list is already being 
ref-counted to prevent its destruction, but the display lists still stop 
working when I close the first view.  It seems as if forcing the 
GdkGLContext to stick around isn't enough, my guess is that when the 
drawable/X window is lost, something happens to the underlying glx 
context.  Looks like I will have to try the hidden widget trick.

Many Thanks!
Tim