[Savage40] Wanted: savage dri HOWTO

[Alex Deucher]

--- Mark van Rossum <mvanross at inf.ed.ac.uk> wrote:

> 
> Thanks all people for creating the DRI drivers for the savage!
> 
> However, I find installing is quite tricky and seems to involve many 
> components. I only got it to work once.
> Good documentation on how to install them seems
> missing/dated/scattered.
> Where can I find it? Perhaps the probo.com site can combine a few 
> pointers.

See the DRI building instructions:
http://dri.sourceforge.net/cgi-bin/moin.cgi/Building
you can also grab daily snapshots against xorg (see the snapshots
section):
http://dri.sourceforge.net/cgi-bin/moin.cgi/Download
actual snapshots:
http://www.freedesktop.org/~dri/snapshots/

> 
> It would also be good to know if old and new setups can co-exist next
> to 
> each other.

yes.  if you rebuild xorg from cvs, you can install in in
/usr/local/X11R6 for example, then adjust your ld.conf appropriately.

> 
> Finally, currently cards with little memory can only start DRI in low
> 
> resolution. So AFAIK you can either start in low res. with DRI, or in
> high 
> res. without DRI. It would be great if the DRI could be enabled
> depending 
> on resolution/depth (changeable with xrandr), without the need to
> restart X.

Depends on what you consider "low res." :)

until we have a good memory manager for the dri/X, we are going to be
stuck with static allocations for the full back and depth buffers. 
Once we get a good memory manager we can allocate offscreen memory on
the fly for back buffers, depth buffers, XAA, Xv, etc.

For now you can use a simple calculation to figure out how much ram
you'll need for 3d:
virtualX * virtualY * bytes/pixel * number of buffers = ram needed for
3d.

16 bpp is 2 bytes/pixel and 24 bpp is 4 bytes/pixel.
number of buffers is 3 (front, back, depth).

since 24 bpp is pretty slow for 3d, in most cases it's best to stick
with 16 bpp. 16 bpp is about twice as fast as 24bpp.

so for example:
1024x768 desktop @16bpp:
1024 * 768 * 2 * 3 = 4718592 bytes (~4.5 MB)
1024x768 desktop @24bpp:
1024 * 768 * 4 * 3 = 9437184 bytes (~9 MB)

Alex

> 
> -- 
> Mark
> 


		
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