Lua bindings for Harfbuzz.
HarfBuzz is an OpenType text shaping engine. It is used in software like Qt, Pango, Firefox, Chromium, XeTeX and LibreOffice.
luaharfbuzz provides bindings for the most common types in Harfbuzz. The initial motivation for building it was to use Harfbuzz with the LuaTeX typesetting system. However, the module isn’t tied to LuaTeX. It can be used with any Lua codebase.
As of 2020, luaharfbuzz is bundled with LuaTeX. Additional support to use the HarfBuzz renderer with LuaLaTeX and other formats is available via luaotfload. Read more:
- TUG 2020 — Marcel Krüger — HarfBuzz in LuaLaTeX
- Typesetting Bangla script with LuaLaTeX
- Bringing world scripts to LuaTeX: The HarfBuzz experiment
Make sure Harfbuzz libraries and headers are installed. before trying to install luaharfbuzz
Install via Homebrew
brew install harfbuzz
apt-get install libharfbuzz0b libharfbuzz-dev
Send a pull request if you want to include specific instructions to install Harfbuzz on your preferred platform.
Before building the package, LuaRocks populates the HARFBUZZ_INCDIR and HARFBUZZ_LIBDIR to point to the correct locations. If you can populate these variables manually before running LuaRocks, you can install luaharfbuzz on any system that supports Lua and Harfbuzz.
If Luarocks and Harfbuzz are installed, luaharfbuzz can be installed like this:
luarocks install luaharfbuzz
Here is some sample code, showcasing the core types and methods in the API.
local harfbuzz = require('harfbuzz')
local serpent = require('serpent') -- luarocks install serpent
-- Harfbuzz API Version
print("Harfbuzz API version", harfbuzz.version())
-- Shapers available
print("Shapers:", serpent.line({ harfbuzz.shapers() }, {comment = false}))
-- harfbuzz.Face
local face = harfbuzz.Face.new('../fonts/notonastaliq.ttf')
print('\nFace upem = '..face:get_upem())
-- harfbuzz.Font
local font = harfbuzz.Font.new(face)
local xs, xy = font:get_scale()
print("\nDefault font scale = X: "..xs..", Y: "..xy)
-- harfbuzz.Buffer
local text = "یہ" -- U+06CC U+06C1
local buf = harfbuzz.Buffer.new()
buf:add_utf8(text)
-- harfbuzz.shape (Shapes text)
print("\nShaping '"..text.."' set with Noto Nastaliq Urdu")
harfbuzz.shape(font, buf, { language = harfbuzz.Language.new("urd"), script = harfbuzz.Script.new("Arab"), direction = harfbuzz.Direction.RTL})
local glyphs = buf:get_glyphs()
print("No. of glyphs", #glyphs)
print(serpent.line(glyphs, {comment = false}))
local opts = { language = harfbuzz.Language.new("eng"), script = harfbuzz.Script.new("Latn"), direction = harfbuzz.Direction.LTR }
local amiri_face = harfbuzz.Face.new('../fonts/amiri-regular.ttf')
local amiri_font = harfbuzz.Font.new(amiri_face)
-- shaping '123' w/o features
print("\nShaping '123' set with Amiri Regular and no features")
buf= harfbuzz.Buffer.new()
buf:add_utf8("123")
harfbuzz.shape(amiri_font, buf, opts)
glyphs = buf:get_glyphs()
print(serpent.line(glyphs, {comment = false}))
-- shaping '123' with '+numr' (numerators)
print("\nShaping '123' set with Amiri Regular with 'numr' feature turned on")
buf= harfbuzz.Buffer.new()
buf:add_utf8("123")
opts.features = "+numr"
harfbuzz.shape(amiri_font, buf, opts)
glyphs = buf:get_glyphs()
print(serpent.line(glyphs, {comment = false}))You can build the package for development purposes using LuaRocks as well. It is recommended that you build it to your local tree (using --local) to isolate it from your actual installation.
luarocks --local make
In order to make changes to the code and run the tests, the following dependencies need to be installed:
Run the test suite:
make spec
Lint the codebase:
make lint
Generate documentation from sources:
make doc
Open a Github issue, or email me at [email protected].