Bug 21664

Summary:	DejaVu letter #119 (ę) has broken slight hinting
Product:	freetype	Reporter:	Tomasz Kalkosiński <tomasz2k>
Component:	general	Assignee:	Werner Lemberg <wl>
Status:	ASSIGNED ---	QA Contact:
Severity:	normal
Priority:	medium	CC:	freedesktop
Version:	unspecified
Hardware:	x86 (IA32)
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:
Attachments:	Slight hinting. Medium hinting Full hinting No hinting.

Description Tomasz Kalkosiński 2009-05-10 14:01:14 UTC

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

Comment 1 Tomasz Kalkosiński 2009-05-10 14:01:47 UTC

Created attachment 25704 [details]
Slight hinting.

Comment 2 Tomasz Kalkosiński 2009-05-10 14:02:06 UTC

Created attachment 25705 [details]
Medium hinting

Comment 3 Tomasz Kalkosiński 2009-05-10 14:02:22 UTC

Created attachment 25706 [details]
Full hinting

Comment 4 Tomasz Kalkosiński 2009-05-10 14:03:13 UTC

Created attachment 25707 [details]
No hinting.

Comment 5 Ben Laenen 2009-05-11 03:22:22 UTC

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

Reassigning to freetype.

Comment 6 Werner Lemberg 2009-05-11 03:44:06 UTC

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.

Comment 7 Tomasz Kalkosiński 2009-05-11 11:51:12 UTC

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?

Comment 8 Werner Lemberg 2009-05-11 22:12:01 UTC

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

Comment 9 Tomasz Kalkosiński 2009-05-12 03:41:40 UTC

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.

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