Harfbuzz is a text shaping library that takes a sequence of unicode codepoints and a font, and selects a sequence of glyphs and placements for those glyphs to represent the desired text. This presupposes things like breaking text into manageable fragments, and the something like the unicode bidirectional algorithm has already processed the data.

This package is intended to provide Haskell bindings to that library.

The standard Harfbuzz library supplies a bunch of optional extras exposed here as well.

To take full advantage of this functionality you'll need Cabal 3.

Then you can incur dependencies on subsets of functionality by e.g. depending on harfbuzz:harfbuzz-subset to just get font subsetting or harfbuzz:harfbuzz-core to just get the core harfbuzz functionality with no additional library dependencies. You can depend on the following sub-libraries:

This is used internally by the library to expose implementation details that hopefully you won't need unless you are extending harfbuzz.

This supplies just the baseline functionality for harfbuzz, which is managing fonts, buffers, and shaping to turn buffers full of codepoints into buffers full of shaped glyphs.

This supplies additional interoperability with the freetype library, letting you cache construction of harfbuzz typefaces from freetype fonts, and access any underlying freetype typeface from a harfbuzz typeface.

This library lets ICU supply the unicode tables needed by harfbuzz.

On a mac:

$ brew install icu4c harfbuzz

The cabal file uses pkg-config to find these on all platforms except for a Mac.

Because Apple ships a crippled subset of ICU, the install for icu4c is keg-only. This means that pkg-config can't find it without assistance.

We try to be clever and find it ourselves, but in the event that we screw up, you can tell pkg-config about icu4c yourself and then tell us to trust pkg-config.

$ export PKG_CONFIG_PATH="/usr/local/opt/icu4c/lib/pkgconfig:$PKG_CONFIG_PATH"
$ cabal new-install harfbuzz-icu -ftrust-darwin-pkg-config

Bindings to the harfbuzz font subsetting library. This library can be used to extract smaller subsets of fonts for specialized purposes, leaving unused features, hints, etc. on the cutting room floor.

Harfbuzz supplies access to many extended forms of tables contained in OpenType fonts for working with variable fonts, color fonts (such as emojis), exposing metrics for OpenType math fonts. This is packaged as a sub-library separate from harfbuzz-core, as it is a lot of stuff, and most users won't need any of it.

Contributions and bug reports are welcome!

Please feel free to contact me through github or on the #haskell IRC channel on irc.freenode.net.

-Edward Kmett