Re: [Dri-devel] R100 GL_ATI_texture_env_combine3

[Brian Paul]

Alexander Stohr wrote:

first let me separate the framebuffer data from GL data
by four more spaces.

 > >>>>> MGA
 > >>>>> r g b a amask    bsz      ar ag ab aa      Xvisual dpth
 > >>>>> 5 6 5 0 00000000  16      16 16 16 0       16
 > >>>>> 8 8 8 8 00000000  32      16 16 16 0       24
 > >>>
 > >>> alphaMask should be 0xff000000.
 > >>
 > >> In the argb8888 READ_RGBA in mgaspan.c, alpha is always
 > returned as
 > >> 255.  One or the other of these is wrong.
 > >
 > > Hmmm, I don't remember if the g200/400 supports dest alpha.
 >  The span
 > > functions would seem to indicate "no".
 >
 > I've changed the mga_dri.c to report 0 for alpha bits, and 24
 > as the buffer size.

Then result should be:

MGA
r g b a amask    bsz      ar ag ab aa      Xvisual dpth
5 6 5 0 00000000  16      16 16 16 0       16
8 8 8 0 00000000  24      16 16 16 0       24

Right.

it seems that no one never ever tried that alpha bits
or used the bsz value.

Most likely, the later. I've never seen any application care about GLX_BUFFER_SIZE.

 > >>>>> GLINT
 > >>>>> r g b a amask    bsz      ar ag ab aa      Xvisual dpth
 > >>>>> 5 5 5 5 000f1000  16      16 16 16 0       15 (pScrn->depth)
 > >>>>> 8 8 8 0 00000000  32      16 16 16 0       24 (pScrn->depth)
 > >>>>
 > >>>> This might be right.
 > >>>
 > >>> Looks OK.
 > > >
 > >> Shouldn't the buffer size be 24 here?
 > >
 > > Ooops, yes.
 >
 > Fixed.

Assumed result:

GLINT
r g b a amask    bsz      ar ag ab aa      Xvisual dpth
5 5 5 5 000f1000  16      16 16 16 0       15 (pScrn->depth)
8 8 8 0 00000000  24      16 16 16 0       24 (pScrn->depth)

Hey and why does 5+5+5+5 = 20, but sum up to 24 in your sheme?

Huh???  It looks like 5+5+5+5 was mistakenly adding to 16, not 24 (or 20).
It's not my "scheme" - I didn't write that code!

i mean the alpha bits would be only 1 bit (my prefrered thing, matches Xvis)
or the bsz is truely 24 for the first line. (dont like that)

here my prefered fix:

GLINT
r g b a amask bsz ar ag ab aa Xvisual dpth
5 5 5 1 00008000 16 16 16 16 0 15 (pScrn->depth)
8 8 8 0 00000000 24 16 16 16 0 24 (pScrn->depth)

sorry i dont have that hardware handy or any specs nearby.

Me neither. I don't know what it's supposed to really be. The span fallback functions treat the first mode as a 565 RGB visual.

I think Alan H. did some work on this driver a while back. Do you remember anything about this?

-Brian



-------------------------------------------------------
This SF.NET email is sponsored by:
SourceForge Enterprise Edition + IBM + LinuxWorld = Something 2 See!
http://www.vasoftware.com
_______________________________________________
Dri-devel mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/dri-devel