Re: [GtkGLExt] Sharing display lists + textures

[Jeff Eberl <jeffeb3 gmail com>]

I have done this before, and I asked this group about it. I found a
method for increasing and decreasing the reference counts, and I just
managed an extra reference count myself. Once I was done with the
context, I removed my separately managed reference.

I think the commands I used were:
gtk_widget_ref and gtk_widget_unref


--Jeff

On Apr 29, 2010, at 12:22 PM, "lindleyf cox net" <lindleyf cox net>
wrote:

> At first glance, GtkGLExt supports a simple interface for sharing
> display lists and textures, which is nice. However, when I actually
> try to use it, I've run into several practical problems and I was
> hoping for some advice on ways to solve them.
>
> I have a GUI which can contain a list of items to be viewed, and
> zero or more figure windows in which to view them. I use GtkGLExt to
> draw the items in the figure windows using OpenGL.
>
> For efficiency, there are some things (texture downloads, display
> list generation) which I'd prefer to only do once the first time
> something is viewed, and then just re-use, even if the item is
> displayed in a different figure window, so it makes sense to share
> display lists + textures between the contexts underlying each
> GtkDrawingArea.
>
> I've figured out a way to do it....provided the first figure window
> stays open. All the other figure windows share with the context from
> there. But if that figure closes, then any windows currently
> existing seem to be all right, but new ones created later don't
> handle the textures properly. The closed windows are not actually
> destroyed, merely gtk_widget_hide()en, but merely unrealizing them
> seems to be enough to destroy the GdkGLContext.
>
> I've long thought that the biggest design flaw in OpenGL is the
> difficulty of creating a context without a window to attach it to.
> If I could just create a "window-less" context then I'd be fine, but
> that seems to be quite difficult using the GtkGLExt interface.
>
> So my question is, first, has anyone encountered this type of
> problem before? And second, what actually happens when I share
> textures/display lists? If I create a texture in context A, then
> tell context B to share with A, then destroy context A, then create
> context C and tell C to share with B----will that texture be
> available to C or not?
> _______________________________________________
> gtkglext-list mailing list
> gtkglext-list gnome org
> http://mail.gnome.org/mailman/listinfo/gtkglext-list