A library that delivers a range of glyphs rendered as SDFs (signed distance fields) in a protocol buffer. We use these encoded glyphs as the basic blocks of font rendering in Mapbox GL. SDF encoding is superior to traditional fonts for our usecase in terms of scaling, rotation, and quickly deriving halos - WebGL doesn't have built-in font rendering, so the decision is between vectorization, which tends to be slow, and SDF generation.
The approach this library takes is to parse and rasterize the font with Freetype (hence the C++ requirement), and then generate a distance field from that rasterized image.
See also TinySDF, which is a faster but less precise approach to generating SDFs for fonts.
By default, installs binaries. On these platforms no external dependencies are needed.
- 64 bit OS X or 64 bit Linux
- Node.js v8-v14
However, other platforms will fall back to a source compile: see building from source for details.
Building from source
npm install --build-from-source
Building from source should automatically install
protozero locally using mason. These dependencies can be installed manually by running
Run tests with
If you make any changes to the C++ files in the
src/ directory, you'll need to recompile the node bindings (
fontnik.node) before testing locally:
Makefile for additional tasks you can run, such as