AKA:

• Lazily loaded web fonts
• Incremental Fonts

Incremental Fonts is a system for incrementally / lazily loading font. It currently includes:

• Python build time code to preprocess fonts for faster serving.
• A Google App Engine python based server.
• Javascript to request/assemble the needed parts and tell the browser to use it.

In the future the server could be built in Java (perhaps using Apache Tomcat?)

Incremental Fonts is an open source project.

• Apache 2.0 license

Incremental fonts works for both OpenType/TrueType and OpenType/CFF fonts.

TachyFont is not an official Google project, and Google provides no support for it.

Overall status 2014-08-27:

• TachyFont is at the proof of concept stage and suitable for giving a demo.

  • Korean fonts are typically 1-5 MB.
  • TachyFont can display the characters in a typical Korean web page in using about 90 KB.
  • For example, "Noto Sans KR Thin" (OTF) has 22K+ glyphs and is 4.2 MB.
  • The Korean version of the Universal Declaration of Human Rights (UDHR) has 396 unique characters.
  • If the Korean UDHR used NotoSansKR-Thin:
    • The WOFF version would be about 3,200 KB.
    • The TachyFont version would be 74 KB:
      • 33 KB for a one-time font framework.
      • 41 KB of character data on this page.
      • That is 2.3% of the WOFF size.
      • Note: all sizes are the compressed sizes.

• There is a demo server at http://green-pear.appspot.com/chrome/tachyfont_demos.html

  • It is not guaranteed to always be working.

• the API is still evolving.

• the includes need to be cleaned up

As of 2014-08-18:

The IndexedDB version has has a limited amount of testing on:

• Chrome

  • tested and working on
    • Android
    • Windows
    • Ubuntu

• FireFox

  • tested and working on
    • Ubuntu
    • Windows 7

• IE

  • tested
    • IE fails to display the font
    • might be that TachyFont is failing their version of OTS
      • IE10 and IE11 on Windows 7

• Safari

  • Safari 7 tested - fast load but does not persist data (IndexedDB not supported)
  • Safari 8 It is expected the IndexedDB version will work allow persisting.

Incremental Fonts is pre-alpha and notes for building / deploying have not yet been finalized or written.

This program uses an unreleased CFF 'flattening' feature in fontTools. Thus the fontTools in this repository must be used when preprocessing CFF fonts; ie: ${PROJECT_LOC}/run_time/src/gae_server/third_party/fonttools-master/Lib/ needs to be on the PYTHONPATH.

• Every font and every revision MUST have a separate path/filename.

• It is highly recommended that a revision number be included in the path.

• You may need to install bitarray

  • pip install bitarray
  • Note: you may need to run this command as root or use sudo

• Put all of your fonts under 'src_font/v1' folder initially. If you use new version of same font put it under new 'src_font/v2' folder.

• Make sure you've added fontTools into PYTHONPATH; eg,

  • cd
  • TOPDIR=${PWD}
  • PYTHONPATH=${TOPDIR}/run_time/src/gae_server/third_party/fonttools-master/Lib/:${PYTHONPATH}

• From an Ubuntu GUI, double click to preprocess_all.py Python 2.7 script and choose Run in Terminal.

• To preprocess via the command line: cd into the ${TOPDIR} and run

  ./preprocess_all.py (This can take a while)

• When you run the command it will report the identifier to use in your web page; eg,

  Found <font-path>. Use following name in javascript: <font-identifier>

• Pass this <font-identifier> into your javascript code when asked to specify font name.

• Right now the command is a work-in-progress and leaves the results in the 'cooked' dir. You will need to manually:

  • copy the 'base' file to ${TOPDIR}/run_time/src/gae_server/fonts/<font-identifier>
  • copy the c* and g* files to ${TOPDIR}/run_time/src/gae_server/data/<font-identifier>

• Run pyprepfnt with the font file

usage: pyprepfnt [-h] [--changefont] [--changebase] [--hinting] [--output OUTPUT] fontfile

positional arguments:
  fontfile             Input font file

optional arguments:
  -h, --help            show this help message and exit
  --hinting  			Does not remove hintings from glyphs if present
  --changebase			Force regeneration of base font
  --changefont			Force to generate all things, overrides changebase option
  --output OUTPUT       Output folder, default is current folder

Example:

./pyprepfnt --changefont --hinting --output ~/MYFONTDATA ~/MYFONTS/a_font_name.otf

• Copy base and base.gz files into the fonts/<font-name>/ folder

• Copy closure_data, closure_idx, codepoints, gids, glyph_data and glyph_table files into the data/<font-name>/ folder

• Use this <font-name> as family-name in styles, and pass this name to the javascript functions

  In our example copy base and base.gz from a_font_name folder into gae_server/chrome/fonts/a_font_name/. From a_font_name folder copy remaining font data into the gae_server/chrome/data/a_font_name/.

• build_time/test/

  • run: py.test

• run_time/src/chrome_client_test

  • TBD

• run_time/src/gae_server_test

  • TBD

TODO: Make a list of items/ideas to improve this project.

• TBD.