DRI2 Protocol Spec Draft

[Michel Dänzer]

On Tue, 2008-09-09 at 12:55 -0400, Adam Jackson wrote:
> On Tue, 2008-09-09 at 18:41 +0200, Michel Dänzer wrote:
> > On Tue, 2008-09-09 at 08:46 -0700, Keith Packard wrote:
> > > On Tue, 2008-09-09 at 13:27 +0200, Michel Dänzer wrote:
> > > > I do wonder if DRI2GetBuffers should return the drawable position
> > > > relative to the origin of each buffer... guess it isn't strictly
> > > > necessary except maybe for the real frontbuffer.
> > > 
> > > One of the requirements in DRI2 is that the 'real' front buffer be
> > > invisible to applications; there's no way the application can sensibly
> > > use those contents. Moreover, the drawable position may change without
> > > any warning due to window configuration.
> > 
> > GLX_EXT_texture_from_pixmap needs the real front buffer.
> 
> It does?  Texturing from a raw window isn't legal.  And if you texture
> from a pixmap named with NameWindowPixmap, you get the offscreen
> storage, not the composited result in the root window's pixmap.  (In
> particular, NameWindowPixmap doesn't work on non-redirected windows.)

The compositing manager creates the GLXPixmap from the pixmap, not the
window. Surely it wants the actual pixmap contents rather than a fake
front buffer with random garbage.


-- 
Earthling Michel Dänzer           |          http://tungstengraphics.com
Libre software enthusiast         |          Debian, X and DRI developer