blackrenderer 0.2.0

A Python-based renderer for OpenType COLRv1 fonts, with multiple backends.

BlackRenderer

Developing a Python-based renderer for OpenType COLRv1 fonts, with multiple backends.

Goals

• Use fonttools to parse COLRv1 data
• Adapter classes for various 2D rendering back-ends:
  1. Debugging/printing (text dump of scene graph / 2D API calls)
  2. skia-python
  3. pycairo
  4. SVG
  5. CoreGraphics (macOS)
  6. ...
• hb-view-like command line app with switchable backend

Usage

BlackRenderer comes with an hb-view-like command line tool, that can be used like this:

$ blackrenderer font.ttf ABC🤩 output.png --font-size=100

Install

If you have a Python 3 environment set up, then all you need to do is:

$ pip install blackrenderer

Install for contributing / setting up an environment

Have Python 3.7 or higher installed.

Open Terminal.

"cd" into the project repo directory.

Create a virtual environment:

• $ python3 -m venv venv --prompt=black-renderer

Activate the venv:

• $ source venv/bin/activate

(You need to activate the virtual environment for every new terminal session.)

Upgrade pip:

• $ pip install --upgrade pip

Install the requirements:

• $ pip install -r requirements.txt
• $ pip install -r requirements-dev.txt

Install blackrenderer in editable mode:

• $ pip install -e .

Run the tests:

• $ pytest

Maintainers: how to release

To cut a release, make an annotated git tag, where the tag is in this format: v1.2.3, where 1, 2 and 3 represent major, minor and micro version numbers. You can add "aN" or "bN" or "rc" to mark alpha, beta or "release candidate" versions. Examples: v1.2.3, v1.2.3b2, v1.2.3a4, v1.2.3rc.

The message for the annotated tag should contain the release notes.

Then use "git push --follow-tags" to trigger the release bot. Example session:

• $ git tag -a v1.2.3 -m "v1.2.3 -- fixed issue #12345"
• $ git push --follow-tags

This process will create a GitHub release, as well as upload the package to PyPI.