On Mon, 28 Oct 2002, Luugi Marsan wrote:
> I'm saying this hoping someone corrects me. It's seems to me that the
> G450 is not actually doing any hardware overlay? Where in the the
> Xserver code is the actually hardware overlay registers touched?
What sort of overlay are you thinking about ?
I have been assuming you are talking about the 32bpp mode "24bpp
direct/8bpp overlay palettized", which is set in
c/programs/Xserver/hw/xfree86/drivers/mga/mga_dacG.c:423 by setting
XMULCTRL to 00000100bin.
"hardware overlay registers" makes me wnder if I was on the wrong track
and you are talking about video overlays ?
It is possible that the G450 isn't doing overlays. I remember that
something connected with 8+24 overlays didn't work when I was playing
with a G400 dual head and a G450 dual head card, but I thought it was
that one of the cards didn't do dual head without HAL, and HAL didn't do
overlays.
> I'm looking at the cfbDoBitblt8To32 function. And seems to me that
> everything is done in software. Actually can anyone tell me the
> difference between cfb and fb? Where does the cfb module lie in the
> Xfree86 architecture?
http://www.xfree86.org/pipermail/xpert/2001-February/005777.html
mentions some of the differences; I believe that for each primitive
there is a cfb function for each depth, but only one fb function.
Hmm, cfbDoBitblt8To32 may or may not be replaced by XAADoBitBlt,
which could be hardware accelerated.
> I'm planning to make a little document explaining all of this because it
> seems that documentation about this is hard to find.
I'm sure I wont be the only one who finds it useful if you do.
--
Dr. Andrew C. Aitchison Computer Officer, DPMMS, Cambridge
[EMAIL PROTECTED] http://www.dpmms.cam.ac.uk/~werdna
_______________________________________________
Xpert mailing list
[EMAIL PROTECTED]
http://XFree86.Org/mailman/listinfo/xpert
