Fontconfig Enable Autohinting
Summary
The automatic-hinting feature in FreeType is enabled by default in Fedora 18.
Owner
- Name: Akira TAGOH
- Email: tagoh@redhat.com
Current status
- Targeted release: Fedora 18
- Last updated: 2012-08-02
- Percentage of completion: 30%
Detailed Description
The automatic-hinting feature in FreeType has been developed to make better rendering without fonts-provided/format-specific hints. It's stable enough because it has been maintained/improved over 10 years since launched and as we got a request in Bug#708525, it may be a good time to enable it by default.
Although it's supposed to work better for most of fonts, there may be the case not working better, for instance, due to the own hinting data gives much better. in this case, the font packagers can adds the following rules in the own config file:
<match target="font">
<test name="family" compare="eq" ignore-blanks="true"><string>FamilyName</string></test>
<edit name="autohint" mode="assign"><bool>false</bool></edit>
</match>
Benefit to Fedora
Enabling the automatic-hinting feature may give us better font rendering.
Scope
The change will be made in Fontconfig as the global configuration. basically no need updating other packages unless it introduces the bad or poor rendering for any fonts because, for instance, the own hinting data may gives us better than this feature. in that case, those fonts may wants to be turn off this feature in their own config file.
Some screenshots for comparison is available at http://tagoh.fedorapeople.org/tmp/hints/
How To Test
Comparing the rendering on ftview in freetype-demos package would be easier way.
$ ftview 8 /path/to/font.ttf
and press 6' to change the rendering mode and f' to toggle auto-hinting.
I'm planning to have a slot on Test Days to estimate how it looks like. maybe 90~95% of the good result may be reasonable threshold.
User Experience
The user will see better rendering as of this feature is enabled.
Dependencies
No dependencies. one line change in the spec file is required to be done.
Contingency Plan
Revert the change if too many fonts packages badly affects or causes the poor rendering. I'd set the due date to the final changes deadline to determine if we should go or no-go, because it may depends on how people feels and need a lot of feedback on this. so the beta testers are necessary for that purpose.
Documentation
http://freetype.sourceforge.net/autohinting/index.html
Release Notes
Fontconfig in Fedora 18 now enables the automatic-hinting feature in FreeType by default, to get better rendering on the desktops.