a just another stupid newbie :)

[Eric Anholt]

On Fri, 2003-12-12 at 09:57, Jaymz Julian wrote:
> So, I wanted transparency to not be as slow as molasses on my system
> (p3m-500), and so i figured i'd try and do something about it rather than
> 
> You should not apply the attached patch to your tree.  I'm still getting
> my head around all of this code, I probably fucked it up :).
> 
> This patch improves performance of xrender composites significantly on 24bit
> displays (in my case, an ati mach64 @1024x768x32).  It could probably be
> improved further, specifically by only doing word writes, although this
> didn't help on my laptop, I suspect it would help on powerpc, and
> know it would on arm.  
> 
> I havn't tested it on non-intel systems yet, but if anyone cares, I'll fix
> the inevitable bugs on powerpc when i fix my mac in a few days.  
> 
> The performance is still pretty terrible on this system (my unscientific
> test program, mplayer, gets around 3-4fps with this patch, and abouit 0.5
> fps without it), but I suspect that I could make it significantly faster
> if I were to throw sse/altivec at it.  
> 
> Is this sort of work on making software eyecandy run at a reasonable speed 
> wanted/needed?  or am i on totally the wrong track here (this stuff is useful
> for my own use anyhow, so feel free to tell me to go to hell :)

I suspect things to improve performance of compositing are quite welcome
:)  I think Keith would be the one to review something like this.

> p.s. is it a percularity of the mach64 driver, or at 32bit visuals kinda
> broken at the moment?

Unfortunately, vesa doesn't want to set up screens beyond 24bpp.  If
mach64 used the fbdev backend it could probably have 32bpp, but fbdev
has been so flaky for me I don't know if I could test it properly,
personally.  The ATI and SiS300 drivers are examples of how both fbdev
and vesa can be supported in one driver, should you want to give it a
try.

-- 
Eric Anholt                                eta@lclark.edu          
http://people.freebsd.org/~anholt/         anholt@FreeBSD.org