Merging aiglx

[Keith Whitwell]

Adam Jackson wrote:
> On Monday 13 March 2006 17:00, David Reveman wrote:
>> On Fri, 2006-03-10 at 11:27 -0800, Ian Romanick wrote:
>>> I guess that's bad news for us. :(  We only support GLX 1.2 and a few of
>>> the extensions that are part of 1.3.
>> I thought it wouldn't be too hard to get GLX 1.3 support implemented.
> 
> It's not terribly hard if you don't worry about conformance, or if you can 
> accept that pbuffers will fail most of the time.
> 
> The pbuffer issue is that they can be shared between direct and indirect 
> contexts.  This is much easier to accomplish when only one driver core is 
> involved (like we have now with aiglx), but still requires different 
> instances of the driver to know how to find them (was re: man we need a 
> memory manager).  A pbuffer implementation that clobbers the pbuffer every 
> time it's touched is perfectly legal, albeit useless, so that's certainly one 
> possibility for the short term.

I'd been wondering about cases where direct and indirect contexts would 
have to use the same buffers (beyond the shared front buffer).  Looks 
like pbuffers is the requirement that will drive that.

The memory manager as it stands has "in principle" support for this sort 
of sharing, but there's definitely work to be done to get it right.  We 
probably won't tackle this immediately but if the GLX support is in 
place, proper pbuffer support won't be that huge of an effort now.

> The rest of the protocol is well specified by now, and shouldn't be 
> particularly tough to wire up if we're not already there.

Keith