Dr Andrew C Aitchison wrote:
Forget what I said. Hardware Overlay does work with the G450. But to tell you the truth, I couldn't find where the MULCTRL register was set. I understand the big picture a lot more now.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.
You are a great help. Thank you very much.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.
Luugi
