font-ligatures


Find ligature replacements for any system font. Useful for determining glyph
substitutions and ranges where ligatures exist within a string of input text.

``
npm install font-ligatures
`

Usage

`js
const fontLigatures = require('font-ligatures');

(async () => {
const font = await fontLigatures.load('Iosevka');
console.log(font.findLigatures('in --> out'));
// {
// inputGlyphs: [ 76, 81, 3, 16, 16, 33, 3, 82, 88, 87 ],
// outputGlyphs: [ 76, 81, 3, 3140, 3128, 33, 3, 82, 88, 87 ],
// contextRanges: [ [ 3, 6 ] ]
// }
})();
`

API

$3

Loads the font with the given name, returning a Promise with a Font
that can be used to find ligature information.

Params

name [string*] - The font family of the font to load
options [object*] - Optional configuration object containing the following
keys:
cacheSize [number*] - The amount of data from previous results to cache
within the parser. The size is measured by the length of the input text
for each call. Turned off by default.

$3

Loads the font at the given path, returning a Promise with a Font that
can be used to find ligature information.

Params

path [string*] - Path to the file containing the font
options [object*] - Optional configuration object containing the following
keys:
cacheSize [number*] - The amount of data from previous results to cache
within the parser. The size is measured by the length of the input text
for each call. Turned off by default.

$3

Loads the font from it's binary data, returning a Font that
can be used to find ligature information.

Params

buffer [ArryaBuffer*] - Binary data of the font file as an ArrayBuffer
options [object*] - Optional configuration object containing the following
keys:
cacheSize [number*] - The amount of data from previous results to cache
within the parser. The size is measured by the length of the input text
for each call. Turned off by default.

$3

Object returned by load(). Includes the following methods:

#### findLigatures(text)

Scans the provided text for font ligatures, returning an object with the
following keys:

inputGlyphs [number[]*] - The list of font glyphs in the input text.
outputGlyphs [number[]*] - The list of font glyphs after performing
replacements for font ligatures.
contextRanges [[number, number]\[\]*] - Sorted array of ranges that must
be rendered together to produce the ligatures in the output sequence. The
ranges are inclusive on the left and exclusive on the right

#### findLigatureRanges(text)

Scans the provided text for font ligatures, returning an array of ranges where
ligatures are located.

Params

text` [string*] - text to search for ligatures

Font Support

This library is designed to support fonts that make use of programming
ligatures. As a result, it is tested against all of the ligatures produced by
the following fonts:

* [Fira Code][]
* [Iosevka][]
* [Monoid][]

If there is another font that you use which doesn't seem to be working, please
open an issue with the font information and where to get it. The most likely
cause is that the font uses a type of substitution which is not yet supported.

Contributing

Want to contribute to the project? Go check out the Contribution
Guide for instructions to set up your development
environment, open an issue and create a pull request.

[Fira Code]: https://github.com/tonsky/FiraCode
[Iosevka]: https://be5invis.github.io/Iosevka
[Monoid]: https://larsenwork.com/monoid