A collection of Go packages for parsing and encoding OpenType fonts.
The main contribution of this repository is the SFNT library which provides support for parsing OpenType, TrueType, WOFF, and WOFF2 fonts.
Also included is a utility called font that can do various useful things with fonts:
go get -u github.com/ConradIrwin/font/cmd/font
Info gets information about the font from the name table:
font info ~/Downloads/Fanwood.ttf
Scrub empties the name table (which can give you a few kb savings, even if you gzip or woff2-encode your font).
font scrub ~/Downloads/Fanwood.ttf
Stats tells you how much space each table is using:
font stats ~/Downloads/Fanwood.ttf
Still missing is support for parsing EOT files (which should be easy to add). Also support for generating WOFF files (which is annoyingly fiddly due to the checksum calculation) and WOFF2 files (needs a Brotli encoder), and a whole load of code around dealing with the hundreds of other SFNT table formats.
On the web there are five main types of font file, TrueType, OpenType, WOFF, WOFF2, and EOT. They all represent the same SFNT information, but are encoded slightly differently. You may also come across SVG fonts, which are a totally different beast.
Inside one of these files, there are two main types of glyphs, TrueType and OpenType (also known as PostScript Type 2, or CFF). There are also a series of supporting tables which contain meta-data about the font (its Name, Copyright Information, Kerning tweaks, Ligatures, etc.etc.)
To confuse things further, OpenType fonts use exactly the same format as TrueType fonts, and a WOFF file can contain an OpenType glyphs or a TrueType glyphs. There's no good solution to the ambiguity in terminolgy, just be aware of it.
Copyright (c) Conrad Irwin 2015, MIT license. See LICENSE.MIT for details