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Revision as of 04:41, 28 June 2018 by Petersen (talk | contribs) (explain upgrades more clearly)


CJK Default Fonts To Noto

Summary

Changes the default fonts for Chinese, Japanese, and Korean (CJK) languages to Google Noto.

Owner

Current status

  • Targeted release: Fedora 29
  • Last updated: 2018-06-28
  • Tracker bug: <will be assigned by the Wrangler>

Detailed Description

This proposal is to change the default fonts for CJK languages to Google Noto and adopts OpenType Collection format to suppress disk space increase as far as possible. Typefaces mapping will change as follows:

Language / f28 Sans-serif Serif Monospace
ja VL Gothic VL Gothic VL Gothic
ko NanumGothic NanumGothic NanumGothic
zh-CN Source Han Sans CN Source Han Serif CN Source Han Sans CN
zh-TW Source Han Sans TW Source Han Serif TW Source Han Sans TW

where the italics means the font is a substitute not actually providing the correct face.

Language / f29 Sans-serif Serif Monospace
ja Noto Sans CJK JP Noto Serif CJK JP Noto Sans Mono CJK JP
ko Noto Sans CJK KR Noto Serif CJK KR Noto Sans Mono CJK KR
zh-CN Noto Sans CJK SC Noto Serif CJK SC Noto Sans Mono CJK SC
zh-TW Noto Sans CJK TC Noto Serif CJK TC Noto Sans Mono CJK TC

Note that all CJK fonts will be unified into one OpenType Collection format file per weight-variant so only the total size for CJK is given for F29. The disk space is calculated from the font file sizes:

\ ja ko zh-CN zh-TW Total
f28 3.9M 13.8M 133.1M 77.4M 228.2M
f29 - - - - 288M

Benefit to Fedora

This change will provides better quality of rendering for all of CJK characters. We will now have default installed Serif face for Japanese and Korean, and also a Monospace face for all of CJK languages and keep consistencies in look among those typefaces.


Scope

  • Proposal owners:
    • Update CJK fonts packages with the proper priority of fontconfig config files
    • Update fonts group in comps [done]
  • Other developers:
    • For application package maintainers:
      • Any GUI applications that don't support TTC or OTC, would need to be fixed.
  • Release engineering: #7592 (a check of an impact with Release Engineering is needed)
  • Policies and guidelines: N/A
  • Trademark approval: N/A

Upgrade/compatibility impact

Existing users upgrading should be unaffected, and will still have the same old default CJK fonts on their system by default. So there will be no need to modify any font configuration files by the hand. However users are encouraged to install the new improved fonts after upgrading like this:

   # dnf install google-noto-sans-cjk-ttc-fonts google-noto-serif-cjk-ttc-fonts


How To Test

  • Check if the default font is changed to Noto:
    • ja
      • LANG=ja_JP.UTF-8 fc-match sans-serif:lang=ja
      • LANG=ja_JP.UTF-8 fc-match serif:lang=ja
      • LANG=ja_JP.UTF-8 fc-match monospace:lang=ja
    • ko
      • LANG=ko_KR.UTF-8 fc-match sans-serif:lang=ko
      • LANG=ko_KR.UTF-8 fc-match serif:lang=ko
      • LANG=ko_KR.UTF-8 fc-match monospace:lang=ko
    • zh-cn
      • LANG=zh_CN.UTF-8 fc-match sans-serif:lang=zh-cn
      • LANG=zh_CN.UTF-8 fc-match serif:lang=zh-cn
      • LANG=zh_CN.UTF-8 fc-match monospace:lang=zh-cn
    • zh-tw
      • LANG=zh_TW.UTF-8 fc-match sans-serif:lang=zh-tw
      • LANG=zh_TW.UTF-8 fc-match serif:lang=zh-tw
      • LANG=zh_TW.UTF-8 fc-match monospace:lang=zh-tw
  • Check the following items on applications (GTK+: gedit, gnome-terminal etc, Qt: kate, konsole etc, X/Xft: xterm etc, Others: LibreOffice, firefox etc)
    • Check applications preference if the above fonts are visible
    • Check applications if the above fonts are rendered properly
    • Check applications if those fonts are chosen as the default font for certain language when the generic family names like sans-serif, serif, and monospace is selected.
      • See the above table for mapping between language and families


User Experience

Users will see better quality of rendering for CJK characters on applications and on desktops.


Dependencies

N/A

Contingency Plan

  • Contingency mechanism: (What to do? Who will do it?) revert all of changes in packages and comps
  • Contingency deadline: Beta freeze
  • Blocks release? No

Documentation

Release Notes