drawbot-skia 0.1.0

Drawbot implements a simple drawing API to generate 2D vector graphics

drawbot-skia

A Python package implementing a subset of the DrawBot API using Skia as a backend.

Work in progress!

Roadmap

1. Get basic shapes working ✅
2. Get basic colors working ✅
3. Get minimal BezierPath object working ✅
4. Get transformations working ✅
5. Get single-line, single style text() working ✅
6. Get Variable Fonts working ✅ (Caveat: #1)
7. Get HarfBuzz shaping working ✅
8. Get OpenType features working ✅
9. Get PNG, JPEG image export working ✅
10. Get PDF export working ✅
11. Get SVG export working
12. Get MP4 export working
13. Get Animated GIF export working
14. Get multi-line, single style text() working
15. Get FormattedString working
16. Get multi-style text() working
17. Get remaining BezierPath methods working
18. Get many-things-I-forgot-to-mention working
19. ...
20. textBox() 🔴 (Major Obstacle)
21. Fill further gaps in DrawBot API

Vision

This project is purely a Python package that implements (part of) the DrawBot drawing API. Using Skia (skia-python) ensures this can be done in a cross-platform way.

A DrawBot-like cross-platform application shell can be developed, but that would be a separate project. Looking forward to the drawbot-qt, drawbot-wx, drawbot-win or any drawbot-* projects of the future!

Compatibility caveats

Some parts of the DrawBot API will be hard or impractical to duplicate.

Skia has only low level support for text, so we'll have to do Unicode processing, line wrapping, hyphenation, and shaping ourselves. In other words, textBox() will be a tough one to crack.

Generally, 100% text compatibility with DrawBot should not be top priority, as matching CoreText behavior will be a huge challenge.

The ImageObject relies heavily on builtin macOS functionality, and it is huge. At best, we should support a small subset of it, but even that is low priority.

Strategy

So far no existing DrawBot code has been reused. Perhaps that small snippets will be copied, perhaps a part of the test suite will be adapted. Other than that I want this to be an independent project, and would like to use Skia’s powers to maximum effect, keeping efficiency and performance in mind. DrawBot's ties to macOS are so strong that it makes platform-neutral code reuse virtually impossible.

Potentially, some higher level code could be shared (for example, drawing code that uses lower level primitives), but that will have to been seen later.

Install

For now, just install from the repo. The quickest way is:

pip install git+https://github.com/justvanrossum/drawbot-skia.git

If you want to see the source code and possibly contribute: clone the repo, and do pip install -e . in the root directory.

Once things settle a bit I want to upload to PyPI.

Usage

To adapt a DrawBot script to drawbot-skia you can do a couple of things:

• Add from drawbot_skia.drawbot imort * at the top of your script
• Or import drawbot_skia.drawbot as db if that's your preferred style

Or you can use the drawbot runner tool from the command line:

• drawbot mydrawbotscript.py output.png

With the drawbot runner tool, you won't need any Drawbot import in the script, nor do you need a saveImage(...) to export results. It pretty much behaves as if you hit "Run" in the classic Drawbot application.