Re: State of Linux graphics

From: Keith Whitwell
Date: Thu Sep 01 2005 - 12:27:34 EST


Ian Romanick wrote:
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Brian Paul wrote:


It's other (non-orientation) texture state I had in mind:

- the texel format (OpenGL has over 30 possible texture formats).
- texture size and borders
- the filtering mode (linear, nearest, etc)
- coordinate wrap mode (clamp, repeat, etc)
- env/combine mode
- multi-texture state


Which is why it's such a good target for code generation. You'd
generate the texel fetch routine, use that to generate the wraped texel
fetch routine, use that to generate the filtered texel fetch routine,
use that to generate the env/combine routines.

Once-upon-a-time I had the first part and some of the second part
written. Doing just that little bit was slightly faster on a Pentium 3
and slightly slower on a Pentium 4. I suspect the problem was that I
wasn't caching the generated code smart enough, so it was it trashing
the CPU cache. The other problem is that, in the absence of an
assembler in Mesa, it was really painful to change the code stubs.

Note that the last part is now partially addressed at least - Mesa has an integrated and simple runtime assembler for x86 and sse. There are some missing pieces and rough edges, but it's working and useful as it stands.

Keith
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/