Re: "floccinaucinihilipilification", or "convolutions, blocking, and windows server 2003"

Around 15 o'clock on Mar 16, Jaymz Julian wrote:

> Do you mean that we should combine all of our ops into a single matrix, or
> that we need to have a special type for various combinations?  IN the former
> cases, see "matrixes are actually very slow and can be optimized away in most
> cases", or if you mean the latter, I'm interested to hear how you think that 
> should look.

In the (unusual) case where there is a combination of convolutions, I 
suggest that we let the client figure out if the combination can be 
expressed as one of the other supported filters or whether it needs to 
fall back to the general array form.  If we find combinations which seem 
particularily interesting, we can always create yet more custom filters.  
What I explicitly want to avoid is any kind of "pipeline" here; I've had 
several very bad experiences with things of that sort in the X server in 
the past.

The client always has the option of using the fast primitives with 
intermediate buffers instead of the general form.

> but that's the programmers perogative, and it's entirely possible that we
> *can* combine some cases into hardware right now (desaturate+blur is a good
> example of where this is true).

You're sliding down the slippery slope here; if you want desaturate + 
blur, then do a desaturate and then a blur as separate operations.  I 
don't want this myself; I want a simple blur operation affecting the alpha 
value of a window so I can draw shadows with it:

	translucent black IN (blur window) OVER root

Yes, Render is not as sophisticated as GL, but the goal is for software 
implementations of Render to be compact and reasonably performant.

If you want something fancier, you're probably doing 3D graphics in 
disguise and may want to use a more appropriate API...

In any case, I'd like to start with the simplest form and see how it 
feels.  I submit that the best guide to how to structure the extension 
will be actual practice.

-keith

_______________________________________________
xserver mailing list
[email protected]
http://freedesktop.org/mailman/listinfo/xserver

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (GNU/Linux)
Comment: Exmh version 2.3.1 11/28/2001

iD8DBQFAVotnQp8BWwlsTdMRAsT7AJ9SMmePQ8LEvKKNbCvM8UZhwTua7QCgo3Tp
gpgvLG0HJEE0duFt7ySDqqI=
=JwCi
-----END PGP SIGNATURE-----