xref: /aosp_15_r20/external/fonttools/README.rst (revision e1fe3e4ad2793916b15cccdc4a7da52a7e1dd0e9)

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What is this?
~~~~~~~~~~~~~

| fontTools is a library for manipulating fonts, written in Python. The
  project includes the TTX tool, that can convert TrueType and OpenType
  fonts to and from an XML text format, which is also called TTX. It
  supports TrueType, OpenType, AFM and to an extent Type 1 and some
  Mac-specific formats. The project has an `MIT open-source
  licence <LICENSE>`__.
| Among other things this means you can use it free of charge.

`User documentation <https://fonttools.readthedocs.io/en/latest/>`_ and
`developer documentation <https://fonttools.readthedocs.io/en/latest/developer.html>`_
are available at `Read the Docs <https://fonttools.readthedocs.io/>`_.

Installation
~~~~~~~~~~~~

FontTools requires `Python <http://www.python.org/download/>`__ 3.8
or later. We try to follow the same schedule of minimum Python version support as
NumPy (see `NEP 29 <https://numpy.org/neps/nep-0029-deprecation_policy.html>`__).

The package is listed in the Python Package Index (PyPI), so you can
install it with `pip <https://pip.pypa.io>`__:

.. code:: sh

    pip install fonttools

If you would like to contribute to its development, you can clone the
repository from GitHub, install the package in 'editable' mode and
modify the source code in place. We recommend creating a virtual
environment, using `virtualenv <https://virtualenv.pypa.io>`__ or
Python 3 `venv <https://docs.python.org/3/library/venv.html>`__ module.

.. code:: sh

    # download the source code to 'fonttools' folder
    git clone https://github.com/fonttools/fonttools.git
    cd fonttools

    # create new virtual environment called e.g. 'fonttools-venv', or anything you like
    python -m virtualenv fonttools-venv

    # source the `activate` shell script to enter the environment (Unix-like); to exit, just type `deactivate`
    . fonttools-venv/bin/activate

    # to activate the virtual environment in Windows `cmd.exe`, do
    fonttools-venv\Scripts\activate.bat

    # install in 'editable' mode
    pip install -e .

Optional Requirements
---------------------

The ``fontTools`` package currently has no (required) external dependencies
besides the modules included in the Python Standard Library.
However, a few extra dependencies are required by some of its modules, which
are needed to unlock optional features.
The ``fonttools`` PyPI distribution also supports so-called "extras", i.e. a
set of keywords that describe a group of additional dependencies, which can be
used when installing via pip, or when specifying a requirement.
For example:

.. code:: sh

    pip install fonttools[ufo,lxml,woff,unicode]

This command will install fonttools, as well as the optional dependencies that
are required to unlock the extra features named "ufo", etc.

- ``Lib/fontTools/misc/etree.py``

  The module exports a ElementTree-like API for reading/writing XML files, and
  allows to use as the backend either the built-in ``xml.etree`` module or
  `lxml <https://lxml.de>`__. The latter is preferred whenever present,
  as it is generally faster and more secure.

  *Extra:* ``lxml``

- ``Lib/fontTools/ufoLib``

  Package for reading and writing UFO source files; it requires:

  * `fs <https://pypi.org/pypi/fs>`__: (aka ``pyfilesystem2``) filesystem
    abstraction layer.

  * `enum34 <https://pypi.org/pypi/enum34>`__: backport for the built-in ``enum``
    module (only required on Python < 3.4).

  *Extra:* ``ufo``

- ``Lib/fontTools/ttLib/woff2.py``

  Module to compress/decompress WOFF 2.0 web fonts; it requires:

  * `brotli <https://pypi.python.org/pypi/Brotli>`__: Python bindings of
    the Brotli compression library.

  *Extra:* ``woff``

- ``Lib/fontTools/ttLib/sfnt.py``

  To better compress WOFF 1.0 web fonts, the following module can be used
  instead of the built-in ``zlib`` library:

  * `zopfli <https://pypi.python.org/pypi/zopfli>`__: Python bindings of
    the Zopfli compression library.

  *Extra:* ``woff``

- ``Lib/fontTools/unicode.py``

  To display the Unicode character names when dumping the ``cmap`` table
  with ``ttx`` we use the ``unicodedata`` module in the Standard Library.
  The version included in there varies between different Python versions.
  To use the latest available data, you can install:

  * `unicodedata2 <https://pypi.python.org/pypi/unicodedata2>`__:
    ``unicodedata`` backport for Python 3.x updated to the latest Unicode
    version 15.0.

  *Extra:* ``unicode``

- ``Lib/fontTools/varLib/interpolatable.py``

  Module for finding wrong contour/component order between different masters.
  It requires one of the following packages in order to solve the so-called
  "minimum weight perfect matching problem in bipartite graphs", or
  the Assignment problem:

  * `scipy <https://pypi.python.org/pypi/scipy>`__: the Scientific Library
    for Python, which internally uses `NumPy <https://pypi.python.org/pypi/numpy>`__
    arrays and hence is very fast;
  * `munkres <https://pypi.python.org/pypi/munkres>`__: a pure-Python
    module that implements the Hungarian or Kuhn-Munkres algorithm.

  To plot the results to a PDF or HTML format, you also need to install:

  * `pycairo <https://pypi.org/project/pycairo/>`__: Python bindings for the
    Cairo graphics library. Note that wheels are currently only available for
    Windows, for other platforms see pycairo's `installation instructions
    <https://pycairo.readthedocs.io/en/latest/getting_started.html>`__.

  *Extra:* ``interpolatable``

- ``Lib/fontTools/varLib/plot.py``

  Module for visualizing DesignSpaceDocument and resulting VariationModel.

  * `matplotlib <https://pypi.org/pypi/matplotlib>`__: 2D plotting library.

  *Extra:* ``plot``

- ``Lib/fontTools/misc/symfont.py``

  Advanced module for symbolic font statistics analysis; it requires:

  * `sympy <https://pypi.python.org/pypi/sympy>`__: the Python library for
    symbolic mathematics.

  *Extra:* ``symfont``

- ``Lib/fontTools/t1Lib.py``

  To get the file creator and type of Macintosh PostScript Type 1 fonts
  on Python 3 you need to install the following module, as the old ``MacOS``
  module is no longer included in Mac Python:

  * `xattr <https://pypi.python.org/pypi/xattr>`__: Python wrapper for
    extended filesystem attributes (macOS platform only).

  *Extra:* ``type1``

- ``Lib/fontTools/ttLib/removeOverlaps.py``

  Simplify TrueType glyphs by merging overlapping contours and components.

  * `skia-pathops <https://pypi.python.org/pypy/skia-pathops>`__: Python
    bindings for the Skia library's PathOps module, performing boolean
    operations on paths (union, intersection, etc.).

  *Extra:* ``pathops``

- ``Lib/fontTools/pens/cocoaPen.py`` and ``Lib/fontTools/pens/quartzPen.py``

  Pens for drawing glyphs with Cocoa ``NSBezierPath`` or ``CGPath`` require:

  * `PyObjC <https://pypi.python.org/pypi/pyobjc>`__: the bridge between
    Python and the Objective-C runtime (macOS platform only).

- ``Lib/fontTools/pens/qtPen.py``

  Pen for drawing glyphs with Qt's ``QPainterPath``, requires:

  * `PyQt5 <https://pypi.python.org/pypi/PyQt5>`__: Python bindings for
    the Qt cross platform UI and application toolkit.

- ``Lib/fontTools/pens/reportLabPen.py``

  Pen to drawing glyphs as PNG images, requires:

  * `reportlab <https://pypi.python.org/pypi/reportlab>`__: Python toolkit
    for generating PDFs and graphics.

- ``Lib/fontTools/pens/freetypePen.py``

  Pen to drawing glyphs with FreeType as raster images, requires:

  * `freetype-py <https://pypi.python.org/pypi/freetype-py>`__: Python binding
    for the FreeType library.

- ``Lib/fontTools/ttLib/tables/otBase.py``

  Use the Harfbuzz library to serialize GPOS/GSUB using ``hb_repack`` method, requires:

  * `uharfbuzz <https://pypi.python.org/pypi/uharfbuzz>`__: Streamlined Cython
    bindings for the harfbuzz shaping engine

  *Extra:* ``repacker``

How to make a new release
~~~~~~~~~~~~~~~~~~~~~~~~~

1) Update ``NEWS.rst`` with all the changes since the last release. Write a
   changelog entry for each PR, with one or two short sentences summarizing it,
   as well as links to the PR and relevant issues addressed by the PR. Do not
   put a new title, the next command will do it for you.
2) Use semantic versioning to decide whether the new release will be a 'major',
   'minor' or 'patch' release. It's usually one of the latter two, depending on
   whether new backward compatible APIs were added, or simply some bugs were fixed.
3) Run ``python setup.py release`` command from the tip of the ``main`` branch.
   By default this bumps the third or 'patch' digit only, unless you pass ``--major``
   or ``--minor`` to bump respectively the first or second digit.
   This bumps the package version string, extracts the changes since the latest
   version from ``NEWS.rst``, and uses that text to create an annotated git tag
   (or a signed git tag if you pass the ``--sign`` option and your git and Github
   account are configured for `signing commits <https://docs.github.com/en/github/authenticating-to-github/managing-commit-signature-verification/signing-commits>`__
   using a GPG key).
   It also commits an additional version bump which opens the main branch for
   the subsequent developmental cycle
4) Push both the tag and commit to the upstream repository, by running the command
   ``git push --follow-tags``. Note: it may push other local tags as well, be
   careful.
5) Let the CI build the wheel and source distribution packages and verify both
   get uploaded to the Python Package Index (PyPI).
6) [Optional] Go to fonttools `Github Releases <https://github.com/fonttools/fonttools/releases>`__
   page and create a new release, copy-pasting the content of the git tag
   message. This way, the release notes are nicely formatted as markdown, and
   users watching the repo will get an email notification. One day we shall
   automate that too.


Acknowledgements
~~~~~~~~~~~~~~~~

In alphabetical order:

aschmitz, Olivier Berten, Samyak Bhuta, Erik van Blokland, Petr van Blokland,
Jelle Bosma, Sascha Brawer, Tom Byrer, Antonio Cavedoni, Frédéric Coiffier,
Vincent Connare, David Corbett, Simon Cozens, Dave Crossland, Simon Daniels,
Peter Dekkers, Behdad Esfahbod, Behnam Esfahbod, Hannes Famira, Sam Fishman,
Matt Fontaine, Takaaki Fuji, Rob Hagemans, Yannis Haralambous, Greg Hitchcock,
Jeremie Hornus, Khaled Hosny, John Hudson, Denis Moyogo Jacquerye, Jack Jansen,
Tom Kacvinsky, Jens Kutilek, Antoine Leca, Werner Lemberg, Tal Leming, Peter
Lofting, Cosimo Lupo, Olli Meier, Masaya Nakamura, Dave Opstad, Laurence Penney,
Roozbeh Pournader, Garret Rieger, Read Roberts, Colin Rofls, Guido van Rossum,
Just van Rossum, Andreas Seidel, Georg Seifert, Chris Simpkins, Miguel Sousa,
Adam Twardoch, Adrien Tétar, Vitaly Volkov, Paul Wise.

Copyrights
~~~~~~~~~~

| Copyright (c) 1999-2004 Just van Rossum, LettError
  ([email protected])
| See `LICENSE <LICENSE>`__ for the full license.

Copyright (c) 2000 BeOpen.com. All Rights Reserved.

Copyright (c) 1995-2001 Corporation for National Research Initiatives.
All Rights Reserved.

Copyright (c) 1991-1995 Stichting Mathematisch Centrum, Amsterdam. All
Rights Reserved.

Have fun!

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