[Xorg] X on OpenGL

[Ian Romanick]

Ted Kaminski wrote:

> I have another concern that sort of relates to this: games.
> 
> With a OpenGL-based X server, we're going to end up using a lot of video memory.  Games these days pretty much need all the resources they can get.

Actually, we'll probably use *less*.  With the open-source drivers, if 
you have a display that's 1600x1200, the back and depth buffers are 
statically allocated to be that size.  If you run the game at 1024x768, 
there's a huge chunk of memory that's unused.  If you treat every window 
like a pbuffer (or some similar abstration), you can kick them out of 
video memory (the same way the kernel kicks applications out of physical 
memory).  You have to make sure that there are no rendering commands 
queued by the graphics engine to render to that surface, but it's still 
completely doable.