Re: terminal.app fails also on 8-bit vnc4server with "Unrecognized color masks"

[Fred Kiefer]

Thank you for testing all the different combination. But the last two 
failure you got were to be expected. The art backend doesn't work with 8 
bit graphic (for strange reasons the xlib backend also doesn't work well 
here, only the cairo backend of GNUstep is working in that setup at the 
moment). And for 32 bit your VNC XServer has a very interesting concept. 
it does not provide an alpha channel in the fourth byte, instead it uses 
 11, 11 and 10 bits for the different colours. This format is currently 
not supported by the art backend. As can be seen in your thunderbird, 
this colour format is not that well supported by other frameworks.

All this go me thinking and I inspected the original error in more 
detail. There you have 6 bit for red, 7 bit for green and 5 bit for 
blue. This is again a rather unusual format the art backend supports
5-6-5 and and 5-5-5 (plus one alpha bit). So I was wrong to begin with, 
this isn't a byte swapping problem after all. You just have rather 
unusual colour formats that currently aren't supported in the art 
backend of GNUstep. Sorry for being misleading.

I would just suggest that you get the gnustep-back0.12-cairo package 
installed and switch to use this backend

defaults write NSGlobalDomain GSBackend libgnustep-cairo

Cheers,
Fred

Stephane Gourichon wrote:
> Stephane Gourichon a écrit :
> > It works on 24-bit vnc4server :
> It doesn't work on 32-bit vnc4server.
>
> So, on a fresh Ubuntu8.04 on 32bit x86 hardware, terminal.app on 
> vnc4server works only at 24bpp.
>
> I noticed that at 32bpp thunderbird display is garbled : all text and 
> icons are replaced by black rectangles. Color backgrounds, lines, etc 
> are ok. Just in case this is useful to you.
>
> Regards.
>
>
> $ Terminal
> 2008-09-05 14:26:07.663 Terminal[15269] WARNING - XGServer is unable to 
> use the fast algorithm for writing to a 32-bit display on this host - 
> perhaps you'd like to adjust the code to work ... and submit a patch.
> 2008-09-05 14:26:07.839 Terminal[15269] gnustep-back(art): Unrecognized 
> color masks: 000007ff:003ff800:ffc00000 32
> 2008-09-05 14:26:07.839 Terminal[15269] Please report this along with 
> details on your pixel format (ie. the four numbers above) to 
> bug-gnustep@gnu.org.Better: implement it and send a patch.)