DejaVu letter #119 (ę) has broken slight hinting

[Tomasz Kalkosiński]

DejaVu letter #119 (ę) has broken slight hinting, while other hintings are ok. I've attached screenshots of all four hinting styles: none, slight, medium and full. You can clearly see that slight is broken. This bug was also in Kubuntu 8 but I report it now, after upgrade to 9.04.

I use this ~/.fonts.conf file:

$ cat /home/spoonman/.fonts.conf
<?xml version='1.0'?>
<!DOCTYPE fontconfig SYSTEM 'fonts.dtd'>
<fontconfig>
 <match target="font" >
  <edit mode="assign" name="rgba" >
   <const>bgr</const>
  </edit>
 </match>
 <match target="font" >
  <edit mode="assign" name="hinting" >
   <bool>true</bool>
  </edit>
 </match>
 <match target="font" >
  <edit mode="assign" name="hintstyle" >
   <const>hintslight</const>
  </edit>
 </match>
 <match target="font" >
  <edit mode="assign" name="antialias" >
   <bool>true</bool>
  </edit>
 </match>
</fontconfig>

$ lsb_release -rd
Description: Ubuntu 9.04
Release: 9.04

$ apt-cache policy ttf-dejavu
ttf-dejavu:
  Installed: 2.28-1

[Tomasz Kalkosiński (tomasz2k)]

DejaVu letter #119 (ę) has broken slight hinting, while other hintings are ok. I've attached screenshots of all four hinting styles: none, slight, medium and full. You can clearly see that slight is broken. This bug was also in Kubuntu 8 but I report it now, after upgrade to 9.04. Please consider that 'ę' is a common letter in polish language and it looks awful compared to 'e'.

I use this ~/.fonts.conf file:

$ cat /home/spoonman/.fonts.conf
<?xml version='1.0'?>
<!DOCTYPE fontconfig SYSTEM 'fonts.dtd'>
<fontconfig>
 <match target="font" >
  <edit mode="assign" name="rgba" >
   <const>bgr</const>
  </edit>
 </match>
 <match target="font" >
  <edit mode="assign" name="hinting" >
   <bool>true</bool>
  </edit>
 </match>
 <match target="font" >
  <edit mode="assign" name="hintstyle" >
   <const>hintslight</const>
  </edit>
 </match>
 <match target="font" >
  <edit mode="assign" name="antialias" >
   <bool>true</bool>
  </edit>
 </match>
</fontconfig>

$ lsb_release -rd
Description: Ubuntu 9.04
Release: 9.04

$ apt-cache policy ttf-dejavu
ttf-dejavu:
  Installed: 2.28-1

[Tomasz Kalkosiński (tomasz2k)]

Created an attachment (id=25704)
Slight hinting.

[Tomasz Kalkosiński (tomasz2k)]

Created an attachment (id=25705)
Medium hinting

[Tomasz Kalkosiński (tomasz2k)]

Created an attachment (id=25706)
Full hinting

[Tomasz Kalkosiński (tomasz2k)]

Created an attachment (id=25707)
No hinting.

[Tomasz Kalkosiński (tomasz2k)]

I've filed a bug report to DejaVu here: https://bugs.freedesktop.org/show_bug.cgi?id=21664 .

[Ben Laenen (benlaenen)]

This is a bug in the autohinter from freetype. There's nothing we can do about this in DejaVu.

Reassigning to freetype.

[Werner Lemberg (wl)]

Don't expect a quick fix. I'm far too busy with other stuff and not
acquainted with the autohinter module. You might directly contact the
FreeType list and file a bug report (at savannah.gnu.org); maybe David
has some time to look into it (which I doubt).

Sorry for that.

[Tomasz Kalkosiński (tomasz2k)]

This bug is already filled on savannah : https://savannah.nongnu.org/bugs/?24357 .

Thank you for support, too bad for ETA :/ Is there some way I can help on it?

[Werner Lemberg (wl)]

Get acquainted with the autohinter code :-)

You might compare the autohinting steps between `e' and `ę' in a debugger
to find out where the problem lies. A first introduction (slightly out of
date) can be found in this article:

  http://www.tug.org/TUGboat/Articles/tb24-3/lemberg.pdf

[Tomasz Kalkosiński (tomasz2k)]

Thanks, but as I can see it's a hude topic to learn. Bug seems sophisticated as it only shows with one letter. I've commented bug on savannah and I've asked David if he can take a look at this.