bugThe FreeType Project - Bugs: bug #37443, False rendering and font hinting...

 
 

bug #37443: False rendering and font hinting for U+0116 and U+0117 symbols

Submitted by:  Ignas B. <vasius>
Submitted on:  Tue 25 Sep 2012 09:09:57 PM UTC  
 
Severity: 3 - NormalItem Group: None
Status: InvalidPrivacy: Public
Assigned to: Werner LEMBERG <wl>Open/Closed: Closed
Planned Release: None

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Thu 27 Sep 2012 06:27:09 AM UTC, comment #3:

This is a font bug, caused by bad bytecode:

https://bugs.freedesktop.org/show_bug.cgi?id=36135

Today, FreeType is quite a mature library. If you find a rendering problem, chances are high that the problem rather lies in the font and not in FreeType. If you use rendering with TrueType hinting, you should always check the rendering on a Windows box.

Werner LEMBERG <wl>
Project AdministratorIn charge of this item.
Wed 26 Sep 2012 05:56:55 PM UTC, comment #2:

Ok, I have results of test with ftView, I tried all ttf fonts in my system on /usr/share/fonts/TTF. Seems that U+0116 (E with glyph - Ė) renders Ok in all fonts, but U+0117 (e with glyph - ė) have problems on two fonts:

DejaVuSans-Bold.ttf
DejaVuSans-BoldOblique.ttf

BoldOblique version glyph only touches top of e, while Bold version of font has the same severe problems as in my screenshot. DejavuSans Mono and DejavuSans Serif versions has no same problems.
Rendering problem in ftview disapears if force auto-hinting (f in ftview) or/and glyph hinting is (h in ftview) turned on.

Freetype version: 2.4.10 (tried package managers (archlinux), compiled versions)
DejaVuSans version: 2.33 (installed throught package manager in my system).
Also I confirmed same bug on another machine, other than my own.
Other tested fonts were Windows 7 fonts other default TTF fonts from /usr/share/fonts/TTF did not showed anything suspicious.

Ignas B. <vasius>
Tue 25 Sep 2012 09:34:40 PM UTC, comment #1:

I can't repeat this, using DejaVuSans.ttf version 2.33. Please try the `ftview' demo program; I've tested versions 2.4.2, 2.4.4, 2.4.6, and the current git, and the dot above `E' and `e' renders just fine.

Werner LEMBERG <wl>
Project AdministratorIn charge of this item.
Tue 25 Sep 2012 09:09:57 PM UTC, original submission:

I have problems with rendering of my locale symbols, namely U+0116 and U+0117 (Ė, ė). They are rendered false almost everytime, if font hinting is enabled above slight level. At slight level symbol is rendered as it should be, except for bold font. Main effected font is „Dejavu Sans“, thought there is probably more fonts.
The problem is old, in early times there was no problem at all, but an 2-1.5 half years ago, nearly all locale symbols got messed up. I can't name freetype version, but with time rendering improved and only problematic symbol left is U+0117 and U+0116.

Locale: lt.UTF-8
Fonts: DeJavu Sans, particulary DeJavu Sans Bold, probably some other fonts have problems.
Hinting Style: false rendering in full and medium hinting modes, for DeJavu Sans Bold hinting does not change anything: it misrenders symbol almost all the time.
Programs effected: many of them, bassicaly every program who uses this symbol in bold at GUI. Libre Office Impress, Chromium, various dialog windows are my tested examples. Strangely enough bug is not present in any editor window and widget.
OS effected: Linux various distributions - Archlinux, Linux Mint, Bodhi Linux are my recent comfirmed distros, some time ago I got this on OpenSUSE, but I can't confirm what the problem status is now. Bug present on any DE I tested (LXDE, KDE, Gnome 3, E17), if font is same.

There link to screenshot how problem looks like: http://imageshack.us/photo/my-images/195/snapshot1sd.png/
Please note, that green underscore marks correct rendering and red false rendering of character. Also note that this screenshot had been taken on slight font hinting settings. Also note boldness of the font. This screenshot had been taken few months ago on libre office impress on KDE. On lxde with my non standard theme it seems that character is rendered correctly, but Chromium still has rendering problem.

Also I attach 2 text files with output of lsof of firefox and chromium.
What other info I could/need to supply?

Ignas B. <vasius>

 

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Attach File(s):
   
   
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Attached Files
file #26630:  chromiumlsof.txt added by vasius (470B - text/plain - output of lsof)
file #26631:  firefoxlsof.txt added by vasius (18KiB - text/plain - output of lsof)

 

Depends on the following items: None found

Items that depend on this one: None found

 

Carbon-Copy List
  • -unavailable- added by wl (Posted a comment)
  • -unavailable- added by vasius (Submitted the item)
  • -unavailable- added by vasius
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    Follow 7 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Thu 27 Sep 2012 06:27:09 AM UTCwlStatusNeed Info=>Invalid
      Open/ClosedOpen=>Closed
    Tue 25 Sep 2012 09:34:40 PM UTCwlStatusNone=>Need Info
      Assigned toNone=>wl
    Tue 25 Sep 2012 09:09:57 PM UTCvasiusAttached File-=>Added chromiumlsof.txt, #26630
      Attached File-=>Added firefoxlsof.txt, #26631
      Carbon-Copy-=>Added -unavailable-

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