Changes/DefaultToNotoFonts

Default To Noto Fonts

Summary

Changing the default fonts for various languages to Noto Fonts as much as possible, to make consistency on the text rendering.

Owner

• Name: Akira TAGOH
• Email: <tagoh@redhat.com>

Current status

• Targeted release: Fedora Linux 36
• Last updated: 2022-03-03
• devel thread
• FESCo issue: #2729
• Tracker bug: #2041929
• Release notes tracker: #788

Detailed Description

For a long time we have used DejaVu fonts as the default font for European and other language scripts. On the other hand some language scripts are not covered by DejaVu and hence have other default fonts. (A few languages like Chinese, Japanese and Korean, as well as Gurmukhi, Sinhala, and emoji are already using Noto fonts by default for some time.) This situation leads to inconsistencies in text rendering on applications and desktops, particularly when mixing different character sets. Further Noto fonts bring some further advantages: the fonts are generally higher quality and support variable fonts for most scripts, making them more compact.

This change aims to provide better experience and consistent text rendering across more languages by replacing DejaVu with Noto as the general system default set of fonts.

The following packages will be installed by default to replace DejaVu's coverage:

• google-noto-sans-vf-fonts
• google-noto-serif-vf-fonts
• google-noto-sans-mono-vf-fonts
• google-noto-sans-arabic-vf-fonts
• google-noto-sans-cherokee-vf-fonts
• google-noto-sans-thaana-vf-fonts
• google-noto-sans-hebrew-vf-fonts
• google-noto-rashi-hebrew-vf-fonts
• google-noto-sans-math-vf-fonts
• google-noto-sans-armenian-vf-fonts
• google-noto-serif-armenian-vf-fonts
• google-noto-sans-canadian-aboriginal-vf-fonts
• google-noto-sans-georgian-vf-fonts
• google-noto-serif-georgian-vf-fonts
• google-noto-sans-lao-vf-fonts
• google-noto-serif-lao-vf-fonts
• google-noto-serif-gurmukhi-vf-fonts
• google-noto-serif-sinhala-vf-fonts

And to replace Abyssinica SIL with Noto according to the request

• google-noto-sans-ethiopic-vf-fonts
• google-noto-serif-ethiopic-vf-fonts

And you can check the table to see what languages will be affected by this change.

Benefit to Fedora

We would get better text rendering on applications and desktops. Also this change should save about 6MB on the fresh install.

$ rpm -qlv dejavu-sans-fonts dejavu-serif-fonts dejavu-sans-mono-fonts sil-abyssinica-fonts | awk 'BEGIN{a=0}{a+=$5}END{print a}'
11432576

$ rpm -qlv google-noto-sans-vf-fonts google-noto-serif-vf-fonts google-noto-sans-mono-vf-fonts google-noto-sans-arabic-vf-fonts google-noto-sans-cherokee-vf-fonts google-noto-sans-thaana-vf-fonts google-noto
-sans-hebrew-vf-fonts google-noto-rashi-hebrew-vf-fonts google-noto-sans-math-vf-fonts google-noto-sans-armenian-vf-f
onts google-noto-serif-armenian-vf-fonts google-noto-sans-canadian-aboriginal-vf-fonts google-noto-sans-georgian-vf-f
onts google-noto-serif-georgian-vf-fonts google-noto-sans-lao-vf-fonts google-noto-serif-lao-vf-fonts google-noto-serif-gurmukhi-vf-fonts google-noto-serif-sinhala-vf-fonts google-noto-sans-ethiopic-vf-fonts google-noto-serif-ethiopic-vf-fonts | awk 'BEGIN{a=0}{a+=$5}END{print a}'
5623849

Scope

• Proposal owners:
  • Update google-noto-fonts and dejavu-fonts to change the priority for fontconfig config.
  • Update langpacks to update the dependency.
  • Update comps to make Noto fonts default.
  • Update lorax templates related to DejaVu.
  • Update fontconfig to change the order of fonts in the builtin config.

• Other developers:
  • Packagers who owns packages implicitly expects DejaVu is installed by default will needs to update the dependency for them.

• Release engineering: #10492

• Policies and guidelines: N/A (not needed for this Change)

• Trademark approval: N/A (not needed for this Change)

• Alignment with Objectives:

Upgrade/compatibility impact

The migration will be done by updating langpacks. after upgrading and rebooting, the default font will be Noto instead of DejaVu.

Since this change aims to switch non-variable fonts to variable fonts, it may not works with legacy applications as expected such as missing some variants. in that case, you can install non-variable fonts packages. the package name will be similar and simply drop -vf from the variable fonts packages.

How To Test

• This change can be simply tested by fc-match command like fc-match sans:lang=<your langauge>, fc-match serif:lang=<your language> and fc-match monospace:lang=<your language>. You can check the expected result from the table.
• Test the text rendering in your favorite application, which use the system default font.

User Experience

Users will see the default font is changed to Noto by this change except for some languages which has much better quality of fonts.

Dependencies

Only dejavu-fonts, langpacks, and fontconfig are required to update. Other packages which explicitly has a dependency to dejavu-fonts are basically optional to update.

Contingency Plan

• Contingency mechanism: (What to do? Who will do it?) Revert the relevant packages updated.
• Contingency deadline: Beta freeze
• Blocks release? No

Documentation

None.

Release Notes

The default fonts for most languages will be Google Noto fonts instead of DejaVu, to keep consistency on the text rendering and to provide better quality among languages.