Copmiz is incompatible with GL screensaver as desktop background (root window)

[Runar Ingebrigtsen]

Binary package hint: compiz

Using a GL screensaver as desktop background makes compiz go crazy, hiding windows and blinking wildly.

Reproduce:
1. Enable extra desktop effects
2. Open a few different apps (gnome-terminal, epiphany, evolution)
3. Enable GL-matrix background:
  $ gconftool-2 --type bool --set /apps/nautilus/preferences/show_desktop false
  $ /usr/lib/xscreensaver/glmatrix -root
4. Switch between windows with alt+tab and super+tab

[Mirco Müller (macslow)]

I assume that you are on a system, which is not equipped with an nvida-based graphics-card. But it would be helpful, if you could further describe your hardware-configuration. That's generally a good idea :)

What you describe sounds very likely to be the well-known shortcoming of the Xorg's DRI. GLX-client applications are always rendered into the front-buffer, ignoring the fact that they are running under a composited environment and thus should not do so. That very fact causes the glitches you are experiencing. Once DRI has "redirected direct rendering" this will automatically solve the issue you are encountering.

[Runar Ingebrigtsen (ringe)]

Thank you for the explanation. :) It makes good sense that what you describe would be the problem here.

[3vi1 (launchpad-net-eternaldusk)]

I observed the same behavior under Kubuntu 7.10 AMD64. I understand this can't be a "high" priority, but it would be great to be ahead of Vista on this one: have it working before it's a standard Windows feature/add-on.