At the moment, Compiz draws each head at a time, shifting the
glViewport() for every head in a xinerama-like setup. However, the
projection matrix is NOT adjusted. This means any translation along
the z-axis will cause problems and any rotation along the x/y axis,
because the projection matrix is centered around the viewport, not the
actual X screen as it has to be to keep the scenery together.
I can have patches to adjust the projection matrix, tested and used
for half a year in Beryl ready ASAP.
We either have to STOP shifting viewports (Why do we do this, in the
first place?) OR apply these patches. Not doing anything is not an
option.
If there are plans to somehow radically change the way outputs are
drawn in the future, then I suggest we implement my patches in the
meanwhile since I haven't seen anything happen on this front since the
last time I brought it up.
--
Regards,
Kristian