X11DRV_DIB_[Get/Set]ImageBits in 1, 4 and 8 bit X modes.

[David Hammerton]

Hi,

I'm presently modifying the X11DRV dibsection code for slight speed
improvements using shared memory pixmaps and the like. Im into the "clean up
and make it work on all systems" stage of thing, and I have a question.
Do people ever worry about what happens if the user is running in a 1, 4 or 8
bit X mode? This has some wacky code, which I am unable to test on my machine
(or any machine around).. So i'm implementing what I think _should_ do the
trick - but I have no idea if it will work..

Is it a big issue?
Any suggestions to the problem?

Thanks,
David

[Hetz Ben Hamo]

This is from my experience only while administrating tons of Linux 
workstations with almost any graphics cards...

1 & 4 bit - very rarely used (unless you're talking about monochrome screens 
in embedded - by then 4 bit is important for gray scales..)

8 bit - used mostly on old system with old graphics cards when 16 bit & up 
are slow - I'm talking about graphics chips like : trident 89xx family, ATI 
Mach 8, Cirrus Logic (all ISA versions), ancient S3 chips, and Number 9 (ISA) 
- on all of those cards it is better to run XFree in 8 bit or else you'll get 
a totally slow graphics...

Everything else today on X86 is running at least 8 bit and on 99% - 16 bit 
and up...

You might want to be careful regarding to 8 bit and up modes - like 15 bit, 
24 and 32 bit. I think Matrox old graphics cards (with their 2.3MB RAM) are 
using packed pixels so it could be a bit problematic...

Hope this helps...

Hetz

On Friday 22 February 2002 01:49, David Hammerton wrote:
> Hi,
>
> I'm presently modifying the X11DRV dibsection code for slight speed
> improvements using shared memory pixmaps and the like. Im into the "clean
> up and make it work on all systems" stage of thing, and I have a question.
> Do people ever worry about what happens if the user is running in a 1, 4 or
> 8 bit X mode? This has some wacky code, which I am unable to test on my
> machine (or any machine around).. So i'm implementing what I think _should_
> do the trick - but I have no idea if it will work..
>
> Is it a big issue?
> Any suggestions to the problem?
>
> Thanks,
> David

[Mike Utke]

David Hammerton wrote:
> Hi,
>
> I'm presently modifying the X11DRV dibsection code for slight speed
> improvements using shared memory pixmaps and the like. Im into the "clean up
> and make it work on all systems" stage of thing, and I have a question.
> Do people ever worry about what happens if the user is running in a 1, 4 or 8
> bit X mode? This has some wacky code, which I am unable to test on my machine
> (or any machine around).. So i'm implementing what I think _should_ do the
> trick - but I have no idea if it will work..
>
> Is it a big issue?
> Any suggestions to the problem?

I recalled François Gouget's VNC work from October and found the message 
where he described how to use it to test various combinations:
http://www.winehq.com/hypermail/wine-devel/2001/10/0278.html

I'm now saying that this will work in 1, 4 or 8 bit configurations, but 
it's worth a try.  It might also be worthwhile to make sure your code 
works with several '-pixelformat's to test compatibility.

Mike

[Francois Gouget]

On Thu, 21 Feb 2002, Mike Utke wrote:
> David Hammerton wrote:
> > Hi,
> >
> > I'm presently modifying the X11DRV dibsection code for slight speed
> > improvements using shared memory pixmaps and the like. Im into the "clean up
> > and make it work on all systems" stage of thing, and I have a question.
> > Do people ever worry about what happens if the user is running in a 1, 4 or 8
> > bit X mode? This has some wacky code, which I am unable to test on my machine
> > (or any machine around).. So i'm implementing what I think _should_ do the
> > trick - but I have no idea if it will work..
> >
> > Is it a big issue?
> > Any suggestions to the problem?
>
> I recalled François Gouget's VNC work from October and found the message
> where he described how to use it to test various combinations:
> http://www.winehq.com/hypermail/wine-devel/2001/10/0278.html
>
> I'm now saying that this will work in 1, 4 or 8 bit configurations, but
> it's worth a try.  It might also be worthwhile to make sure your code
> works with several '-pixelformat's to test compatibility.

You can use VNC to test 8bpp true-color modes, but I think David
Hammerton had 'palettized' modes in mind. In that case, the only
solution I can see is to run the VGA XFree driver. It's not as practical
but is the only solution I know of. Pretty much all graphics cards
should be able to use it as all it requires is VGA support.

--
Francois Gouget         [e-mail]        http://fgouget.free.fr/
The nice thing about meditation is that it makes doing nothing quite respectable
                                  -- Paul Dean