Re: Why run xserver on the OpenGL API?

Kendall Bennett wrote:
> Keith Packard <[email protected]> wrote:
> 
> 
>>Around 19 o'clock on Nov 25, Dave Dodge wrote:
>>
>>>Consider that if they aren't open source, some Linux distributions
>>>simply will not include the drivers even if they exist. So while you may
>>>have OpenGL on every Linux desktop, it may not be hardware accelerated
>>>on every desktop even if drivers are available (unless the owner does
>>>the extra work of finding and installing the add-on drivers). Which is
>>>pretty much the current situation.
>>
>>That's why it's reasonable to provide a portable library interface
>>between applications and the underlying graphics hardware interface
>>layer.  
>>
>>Requiring OpenGL on open source platforms just isn't practical in
>>the near term.  Taking advantage of OpenGL where available is
>>certainly to be encouraged though, the current mindless duplication
>>of rendering code is only slowing down development and making
>>distribution and deployment far too difficult. 
> 
> 
> I am a bit fuzzy about exactly how you plan to 'take advantage of OpenGL 
> where available'. I was under the impression we were talking about DRI 
> drivers that would be ported to sit under the new system. But if we are 
> talking about say ATI or NVIDIA closed source OpenGL drivers, how exactly 
> would they fit into this picture? I mean OpenGL per-se on Linux today 
> intrinsicly requires X11 support, since it needs all the glX baggage that 
> goes along with it. You simply can't write a client program that does not 
> require X11 to go with it.

Actually, the "mini glx" project we did over the past year or so lets 
you run OpenGL apps without X.  It has a "faked" glx interface.


> Since I am sure we are not talking about building an X server based on 
> OpenGL that requires an existing OpenGL enabled X server to run, perhaps 
> you can clear this up?
> 

One of our goals (at least for Jon and myself and a few others) is to 
design a new OpenGL interface (similar to GLX) that doesn't require X. 
  That is, you could forego X entirely and program with the OpenGL API 
and some GLX-like glue.  There's a lot of people interested in running 
OpenGL-based apps in a full-screen, non-windowed environment.

Once we have such stand-alone OpenGL drivers, the next step is to 
layer the X server on top of it.

If this approach works as well as we hope, we'd be happy to have 
NVIDIA and ATI adopt it for their closed drivers.

Also, if you're writing a 3D driver, working outside of X can simplify 
things a bit.

-Brian