Xgl and direct rendering

[Michel Dänzer]

On Wed, 2006-03-01 at 17:34 +0100, Matthias Hopf wrote:
> 
> > > > This "get-out-of-the-way-I'm-going-fullscreen" protocol is also needed
> > > > for fullscreen 3D games with direct rendering.
> > > This shouldn't be much of a problem, the composition manager should know
> > > when a single nontransparent window is shown fullscreen.
> > Sure, but a mechanism to have the fullscreen front buffer be scanned out
> > directly by the display hardware would still be nice.
> 
> Right... But that isn't easily possible, as a front buffer suddenly
> might become transparent, or moved to the background, and then we would
> have to switch to an off-screen buffer, which is not doable right now.

It could always be the same buffer. In that case, you'd just have to
switch back to scanning out the root/compositor window buffer and
compositing the desktop.


> >       * Video playback is not the only use for overlays.
> 
> What other uses do you see for overlays?

Think of the overlay as providing two surfaces that can be combined more
or less arbitrarily, and the scanout location of each can be changed
independently, and use your imagination. :) (Or alternatively, look at
what the proprietary drivers use it for ;)


-- 
Earthling Michel Dänzer      |     Debian (powerpc), X and DRI developer
Libre software enthusiast    |   http://svcs.affero.net/rm.php?r=daenzer