[compiz] Clipped screen when using multiple X screens (regression) ?
ubuntu at tjworld.net
Sat Feb 21 10:38:00 PST 2009
Please see the Ubuntu bug report for photographs and logs of this
problem "Clipped area for multiple X screens with different dimensions":
Thanks to some great support and suggestions in #compiz-fusion-dev I've
made some progress in trying to pin this issue down.
I've operated with compiz and multiple X screens for about 2 years, both
on nvidia GeForce Go 7600 and Matrox G450 dual-head.
I'm now testing for Ubuntu Jaunty and met an apparent regression.
The problem appears to be that compiz is getting screen 0 geometry for
screen 1, and as screen 0 is 800 pixels high and screen 1 is 1024 pixels
high, screen 1 ends up with a black band across the lower section of the
monitor that appears to be 224 (1024-800) pixels high.
The issue occurs when compiz manages both screens and when it manages
just screen 1:
DISPLAY=:0.1 compiz --replace --only-current-screen ...
After doing a lot of investigation and testing of the current Ubuntu
Jaunty package (1:0.7.9+git20090211-0ubuntu4) with various debug logging
I began bisecting.
I started at the last known good package (1:0.7.4-0ubuntu7). That works
find on Ubuntu Hardy 8.04.2.
Building that package on Jaunty I found it suffers the same problem.
Originally I tagged the bug as being in Xorg and then discounted that
when I found it was specific to Compiz.
Now however, I'm beginning to wonder if the newer xserver packages have
a problem and are incorrectly returning screen 0 geometry at some point.
So, can you tell me which calls to the xserver will return the geometry
of the screen(s) that compiz will rely on for clipping so I can include
some debug logging to test the return values?
More information about the compiz