Pacman "Meta-packages" and "provides"-ta

Question

Hi there..
I'm building some packages on occasion(whenenver I run over something that I want but it isn't in the repositories, yet)...
Many of those packages are games and many games nowadays depend on some implementation of OpenGL.
Now, there's already a dependency called "x-server" which can be either "xorg" or "xfree" or something..
My question is: Is there something like that as well for OpenGL?  Which can be satisfied by installing one of nvidia-drivers, Mesa, $some_other_opengl_implementation?
Or maybe there's a list of these things?
I just had a look into the nvidia driver package and it doesn't seem to provide OpenGL(as from a packager's point of view), so I can't really count on that
So what do I do now?      Ask the NVIDIA packager to include that provides-line in the PKGBUILD?
Or can I do dependencies on something like "mesa OR nvidia"?

Answer 1

http://dri.freedesktop.org/wiki/
The DRI is an integral part of XFree86 4.x , and integrates with Mesa, an open source implementation of the OpenGL API. Several 3D accelerated drivers have been written to the DRI specification, including drivers for chipsets produced by ATI, Matrox, 3DFX, and Intel.
ftp://download.nvidia.com/XFree86/Linux … README.txt
The NVIDIA Accelerated Linux Driver Set brings both accelerated 2D
functionality and high performance OpenGL support to Linux x86 with the
use of NVIDIA graphics processing units (GPUs).
Mesa is already included/integrated with xorg/xfree. It's also available as a separate package too (more recent version).
Nvidia replaces libgl with it's own version during installation process (that's one of the reasons you should reinstall nvidia drivers when you upgrade xfree/xorg package). You can see it in your nvidia-installer log in /var/log or
ls -l /usr/lib/libGL*
lrwxrwxrwx 1 root root 21 2004-11-14 23:01 /usr/lib/libGLcore.so.1 -> libGLcore.so.1.0.6629
-rwxr-xr-x 1 root root 7230360 2004-11-14 23:01 /usr/lib/libGLcore.so.1.0.6629
-rw-r--r-- 1 root root 653 2004-11-14 23:01 /usr/lib/libGL.la
lrwxrwxrwx 1 root root 10 2004-11-14 23:01 /usr/lib/libGL.so -> libGL.so.1
lrwxrwxrwx 1 root root 17 2004-11-14 23:01 /usr/lib/libGL.so.1 -> libGL.so.1.0.6629
-rwxr-xr-x 1 root root 442592 2004-11-14 23:01 /usr/lib/libGL.so.1.0.6629
You shouldn't install mesa together with nvidia drivers because you will experience strange effects :-)
All of this means that normally you should only use x-server as a dependency and do not include nvidia or mesa at all. Unless of course an application docs says something else (IMO if a package really needs mesa - the one available as a separate package - you should also put nvidia into "conflicts").