Accelerated graphics questions (many!)

[Jean-Eric Cuendet]

Hi,
Since Xgl is out, hardware accelerated is "the* topic out there!

Would someone explain me exactly what is involved to get 3d acclerated?
As I understand, there is OpenGL, which is a library (Mesa). It gives 
some 3d functions. Without 3d acceleration, the CPU do the hard job.

But if we have a 3d card, then we need something to make that OpenGL 
fast. At this point things get harder to understand...

There is first the DRI/DRM driver. What resides in kernel? DRM? Both?
Is DRI only a shared library that is loaded by OpenGL? Or is it a kernel 
module?

What is the GLX module? A wrapper around OpenGL/Mesa so it is accessible 
through X11?

There are drm.ko and i915.ko modules in /lib/modules/... , what are they 
for? Is that the DRM or the DRI part of Intel 915 platform? Does that 
provide hardware accelerated for Intel GMA 915?

What about integrating r200/r300 drivers in Ubuntu? They seem to provide 
accelerated 3d for ATI cards. Is there a non-free issue?

Thanks to answer all these questions.
Bye.
-jec