KDE Translucency/Composite

[Ravnos]

I tried searching but couldn't find anything, so here goes...

When I try to run Nexuiz all I get is a black screen, and a couple of squares reveal a bit of the logo, nothing else though. This happens with Nexuiz 1.5 and 2.0. It only happens when I have Translucency enabled in KDE though. If I disable translucency (but still have Composites enabled in my xorg.conf) the game works fine. This happens with both the glx and sdl versions. The GLX module is loading in X, and glxinfo gives the expected output.

Now, I know that this is probably not a supported configuration so I'm not reporting it as a bug or anything, even KDE says that translucency is experimental so I don't expect you guys to work around a corner case like this. The reason I'm posting is because I'm sure there are a few other KDE users here, and I'm wondering if any other people have come across this and if there's maybe a workaround that can let me have my cake and eat it, too. I know that scummvm works if I add XLIB_SKIP_ARGB_VISUALS=1 to the commandline, and the KDE docs suggest SDL_VIDEO_X11_VISUALID=0x24 as well, but neither of those work with Nexuiz. Is there another option I can maybe add?

In case version numbers are needed, it's Gentoo 2006, KDE 3.5, X.Org 6.8.2, and Nexuiz 1.5/2.0.

If this is a waste of everyone's time, you can just tell me to get lost and I'll be on my merry, but help would be appreciated.

[dominic]

Are you using a NVIDIA card ? If that is the case, you should know that by default NVIDIA drivers disable hardware accelerated 3D when using Composite. That's because OpenGL windows can't be made transparent and it would also cause weird visual effects if a transparent window was placed over it. Don't take what I'm about to write as a fact, but I don't think it would brake anything, the OpenGL window would simply appear to be solid blue under the transparent window. There is an option in NVIDIA's driver to enable OpenGL when Composite is enabled. Again, I warn you, I think it won't break anything, but I'm not 100% sure, so do it AT YOUR OWN RISKS. Here is the documentation of the option taken from the drivers' README :

Option "AllowGLXWithComposite" "boolean"

Enables GLX even when the Composite X extension is loaded. ENABLE AT YOUR OWN RISK. OpenGL applications will not display correctly in many circumstances with this setting enabled.

This option is intended for use on X.Org X servers older than X11R6.9.0. On X11R6.9.0 or newer X servers, NVIDIA's OpenGL implementation interacts properly by default with the Composite X extension and this option should not be needed. However, on X11R6.9.0 or newer X servers, support for GLX with Composite can be disabled by setting this option to False.

Default: false (GLX is disabled when Composite is enabled on X servers older than X11R6.9.0).

[Ravnos]

Yeah, I have that enabled. Like I said, it works fine with composites enabled but no transparencies enabled in KDE. It's the transparencies that are screwing everything up and I'm wondering if there's a commandline switch I can use to turn them off for the game and have them back on again when I exit.