[cairo] glitztest and pbuffers

[David Reveman]

On Wed, 2004-05-26 at 18:51 -0700, Jon Smirl wrote:
> --- David Reveman <c99drn at cs.umu.se> wrote:
> > > The background surface is created as an offscreen surface but then
> > > glXMakeCurrent() is used on it. This makes me think it was meant to be a
> > > pbuffer.
> > 
> > A backend should never try to make a "not drawable" surface current, it
> > should instead make the root context and the root drawable current and
> > return "not supported" to the glitz core.
> 
> This may be causing me problems then, I added the close root call to work around
> minglx's single window support.

The backend doesn't necessarily need to make the root context and the
root drawable current, but it must make sure that some context is
current so that "glitz core" can create textures and draw/read pixel
data to them. If the onscreen window is current then that's just fine.
With the GLX backend it's possible to create textures without actually
having an onscreen surface, this is why the GLX backend need the root
context and the root window.
 
-David