ofxHarfBuzz

openFrameworks addon wrapping HarfBuzz for Unicode text shaping.

What it does

Takes a UTF-8 string + font + options and returns a list of glyph IDs with positions (advances and offsets). Handles ligatures, kerning, Arabic/Hebrew bidirectional text, CJK, and OpenType features correctly — things ofTrueTypeFont does not do.

Classes

ofxHbFace

RAII wrapper around hb_face_t. Loads font bytes from disk.

ofxHbFace face;
face.load("fonts/NotoSansCJK.ttf");

hb_face_t*                   face.get();
const std::vector<uint8_t>&  face.getFontData();  // raw bytes (share with Skia)

ofxHbFont

RAII wrapper around hb_font_t. Created from a face at a given pixel size.

ofxHbFont font;
font.create(face, 48.0f);

ofxHbShaper

Stateless shaper. Calls hb_shape() and converts the result to ofxHbGlyphRun.

ofxHbShaper shaper;
ofxHbGlyphRun run = shaper.shape("こんにちは", font);
for (auto& g : run.glyphs) {
    // g.glyphId, g.advance, g.offset, g.cluster
}

Types

struct ofxHbGlyph {
    uint32_t  glyphId;   // glyph index in the font
    uint32_t  cluster;   // byte offset in source UTF-8
    glm::vec2 advance;   // pen advance (x, y) in pixels — 26.6 fixed converted to float
    glm::vec2 offset;    // glyph placement offset from pen position
};

struct ofxHbShapeOptions {
    std::string        language  = "und";                        // BCP 47 e.g. "ja", "ar"
    std::string        script    = "";                           // ISO 15924 e.g. "Latn", "Arab"
    ofxHbTextDirection direction = ofxHbTextDirection::LeftToRight;
    std::vector<std::string> features;                          // e.g. {"liga=1", "kern=1"}
};

struct ofxHbGlyphRun {
    std::vector<ofxHbGlyph> glyphs;
    ofxHbShapeOptions        options;
    float                    fontSize;
};

Building the library

# macOS universal (arm64 + x86_64)
bash scripts/build_harfbuzz_macos.sh

Linux x64
bash scripts/build_harfbuzz_linux.sh

Windows — run in PowerShell
.\scripts\build_harfbuzz_windows.ps1

Requires CMake 3.15+. No ICU, GLib, or FreeType dependency. Output: libs/harfbuzz/lib/{osx,linux64,vs}/ + libs/harfbuzz/include/ libs/ is git-ignored; run the script once per machine.

CI

HarfBuzz is built from source on the first CI run and cached thereafter.



Platforms: macOS (Make + Xcode), Linux x64, Windows x64

Requirements

• openFrameworks 0.12.0+
• HarfBuzz 10.4.0

License

MIT