The fonts are generated rather than hand-authored. The build script emits glyph outlines and GSUB feature logic, then compiles them into dist/qrfont-*.ttf. The default build compiles the delimiter parser, byte expansion, Reed-Solomon parity circuit, QR module placement, and fixed mask rendering.

Printable ASCII glyphs are copied from Liberation Sans Regular, scaled into the QR Font em square, so text outside bracketed QR blocks renders as ordinary text in the same font. Liberation is a reserved font name under the source font license, so the generated families are named QR Font 1-L, QR Font 2-L, and QR Font 3-L.

Build

make

The project uses uv for Python dependency management. You can also run the generator directly with:

uv run tools/build_font.py

By default the generator reads Liberation Sans Regular from:

/usr/share/fonts/truetype/liberation/LiberationSans-Regular.ttf

Use a different compatible TrueType source with:

uv run tools/build_font.py --base-font /path/to/BaseFont-Regular.ttf

To try the full generated Reed-Solomon circuit:

make full-parity

This is also the default make path. It emits thousands of contextual lookups and usually takes noticeably longer than a layout-only build.

For a faster layout-only build with placeholder zero parity:

make fast-placeholder

To inspect the shaped glyph stream:

uv run tools/shape_debug.py '[a]' '[b]'

Outputs:

dist/qrfont-*.ttf (1-L, 2-L, and 3-L font files)
dist/index.html (interactive web demo)
build/qrfont-*.fea (generated OpenType feature files)

Open dist/index.html in a browser and type bracketed text such as [hello]. Mixed text such as abc[def]ghi should render as normal text, then a QR code for def, then normal text.

License

The generated font is a Modified Version of Liberation Sans Regular and is licensed under the SIL Open Font License, Version 1.1. See LICENSE-OFL.txt and NOTICE.md.

Notes

This is a proof-of-concept font. It relies on OpenType shaping, so it needs an environment that applies GSUB features to the font. Inputs inside a QR block are bounded to printable ASCII, up to 17, 32, or 53 characters depending on the selected font version.