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

[Thierry Bernier <thiberlog free fr>]

Timothy M. Shead 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.

I have a similar problem under MinGW (over XP) : when I reparent a 
Widget containing a GtkGLExtended widget in its children tree, the 
displqy lists are losts after the reparent. Every other GL call works, 
but calling the lists draws nothing.

I will post a bug, if you think this is really one.

--
Thiery Bernier