Fontconfig - Nov 2005 - Endian issue with sub-pixel anti-aliasing

<quote who="Keith Packard">
> 	$ export XFT_DEBUG=96
> 
> That''ll display a lovely ascii graphic for each glyph rasterized
and show
> how the various pieces are built so we can tell whether the glyphs are
> rasterized wrong or whether the X server is drawing them incorrectly.
Ooh, that''s very sweet.

  http://www.gnome.org/~jdub/random/xftdebug.log.bz2 (11k bz2, ~60k raw)

Thanks!

- Jeff

-- 
linux.conf.au 2004: Adelaide, Australia         http://lca2004.linux.org.au/
 
     "Everyone''s a little queer, why can''t she be a
little straight?" -
                           Weezer, Pink Triangle

<quote who="John Ellson">
> Are you using sub-pixel aliasing that was set up for one display device,
> on a different display device?
No. I''m running a GTK+ application remotely, which inherits the AA
XSETTING
from the current display. I don''t even use sub-pixel AA on the x86 box
that
the app is executing on.

The subtle ugliness of incorrect sub-pixel AA orientation is very different
to this angelic yellow glow. :-)

- Jeff

-- 
GU4DEC: June 16th-18th in Dublin, Ireland             http://www.guadec.org/
 
   "Oh my god, if I get killed, Meryl Streep will get an award playing my
          life and I would be really pissed off." - Susan Sarandon

Around 17 o''clock on Apr 22, Jeff Waugh wrote:
> Not entirely sure whether this is a freetype or Xft issue, so mailing here
> for further input. I have the latest freetype/xft/fontconfig stack built on
> my x86 machine, working as expected. However, when displaying on my XF86
4.3
> PPC, I get this lovely yellow glow:
	$ export XFT_DEBUG=96

That''ll display a lovely ascii graphic for each glyph rasterized and
show
how the various pieces are built so we can tell whether the glyphs are 
rasterized wrong or whether the X server is drawing them incorrectly.

-keith

Around 2 o''clock on Apr 23, Jeff Waugh wrote:
> Ooh, that''s very sweet.
Looks like we''re rasterizing the glyphs correctly.  Now we need to
figure
out if the images are getting put on the wire correctly.  For that,
you''ll
need xscope which you can fetch from CVS at keithp.com.

$ xhost +
$ xscope -v4 -hlocalhost -i27 >& xscope.log < /dev/null &
$ export DISPLAY=localhost:27
$ <application>
$ kill <xscope>

That''ll generate a *huge* log file which will show every single byte
sent
between the X server and the application.  Dig through that to find the 
RenderAddGlyphs request and we''l see what bytes are getting sent to the
X
server.

-keith

Jeff,

Are you using sub-pixel aliasing that was set up for one display device, 
on a different
display device?

My understanding of subpixel aliasing is that it uses knowledge of the 
location of the
color bars within each pixel.   Different display devices (partic, LCDs) 
use different arrangements
of color bars: e.g. horizontal or vertical bars, rgb or bgr ordering.

What happens if you swap display devices?

John Ellson


Jeff Waugh wrote:
>Hi everyone,
>
>Not entirely sure whether this is a freetype or Xft issue, so mailing here
>for further input. I have the latest freetype/xft/fontconfig stack built on
>my x86 machine, working as expected. However, when displaying on my XF86 4.3
>PPC, I get this lovely yellow glow:
>
>  http://www.gnome.org/~jdub/random/endian-glow.png
>
>Pointers?
>
>Thanks,
>
>- Jeff
>
>  
>

Hi everyone,

Not entirely sure whether this is a freetype or Xft issue, so mailing here
for further input. I have the latest freetype/xft/fontconfig stack built on
my x86 machine, working as expected. However, when displaying on my XF86 4.3
PPC, I get this lovely yellow glow:

  http://www.gnome.org/~jdub/random/endian-glow.png

Pointers?

Thanks,

- Jeff

-- 
GU4DEC: June 16th-18th in Dublin, Ireland             http://www.guadec.org/
 
       "Have you ever kissed a girl?" - Bryan Cantrill to Dave Miller