crates.io · #3251 most downloaded on crates.io

harfrust

0.14.011M downloads/moharfbuzz/harfrust ↗New releases in your daily digest, changelog included.

A complete HarfBuzz shaping algorithm port to Rust.

Last release 4 days ago
04 Oct 2026
Ships fairly regularly
a new release about every 4 weeks
Nearly every release is documented
notes for 29 of 29 stable releases
2 versions withdrawn
withdrawn after publishing
1 years old
31 releases · first in 2025

Release timeline

31 releases since 2025

20252026

One column per month.

Releases

0.14.04 Oct 20262 sources agree
This release matches HarfBuzz v14.5.1 , and has an MSRV (minimum supported Rust version) of 1.85.
This release matches HarfBuzz v14.5.1, and has an MSRV (minimum supported Rust version) of 1.85.

Breaking changes

Replace UnicodeBuffer and GlyphBuffer with one Buffer that holds input
Unicode code points before shaping and glyphs afterward. ContentType
reports which state the buffer is in. The old buffer types and their
conversion methods have been removed.

Replace the FontRef entry point with Font from read-fonts, re-exported
as harfrust::Font. Create a ShaperFont from a Font (or one of its
instances) before shaping.

Replace the old Shaper, ShaperBuilder, ShaperInstance, and ShaperData
API with ShaperFont.

Configure scale and custom FontFuncs on ShaperFont instead of
ShapeOptions.

Shape in place with harfrust::shape(&shaper_font, &mut buffer, options).
It returns Result<(), ShapeError> for invalid shaping state or properties,
rather than returning a separate glyph buffer. Check
Buffer::allocation_successful() separately for allocation or shaping-limit
failure.

Migration

Replace UnicodeBuffer construction and the returned GlyphBuffer with a
single mutable Buffer. For example, with font_data containing font bytes:

use harfrust::{shape, Buffer, Font, ShapeOptions, ShaperFont}; let font = Font::new(font_data, 0).expect("invalid font"); let shaper_font = ShaperFont::new(&font); let mut buffer = Buffer::new(); buffer.push_str("Hello"); buffer.guess_segment_properties(); shape(&shaper_font, &mut buffer, ShapeOptions::new()).expect("shaping failed"); let glyphs = buffer.glyph_infos(); let positions = buffer.glyph_positions();

Use buffer.clear() to reuse its allocation for another run, then push new
text. Call guess_segment_properties() or set the direction and other segment
properties explicitly before shaping.

Use ShaperFont::set_scale or set_scale_separate for scaling, and
ShaperFont::set_font_funcs for custom font callbacks. ShaperFont borrows the
Font and any supplied callbacks, so it is intended as a short-lived shaping
view; keep the Font and callbacks alive and construct a ShaperFont as needed.
ShapeOptions holds per-call features, an optional plan, and point size.

Other changes

Update read-fonts to 0.45.0 and use its current font model API.

Update the built-in Unicode data to 18.0. Add Jurchen, Proto-Cuneiform, and
Seal script constants to the Rust and C APIs and route them through USE.

Treat U+180F as default ignorable during shaping.

Support hexadecimal OpenType language and script overrides in x-hbot-
and x-hbsc- private-use subtags, such as x-hbot-4d4f4e54 for MONT.

Expose Unicode composition, one-step canonical decomposition, and canonical
combining classes through the public harfrust::unicode module.
Decomposition returns a Decomposed enum.

Add the harfrust_capi crate, a C API mirroring the shaping half of
HarfBuzz's API with an hr_ prefix in place of hb_.

Speed up repeated hr-shape runs and contextual lookup matching.

Reduce OpenType subtable cache memory by boxing the two large contextual
cache variants.

Leave a GPOS mark unattached when it is more than 32767 glyphs from its base,
as HarfBuzz does, instead of storing a truncated attach_chain that
mispositioned the mark.

Fix would_apply for format 3 (coverage-based) contextual lookups, which
never matched, so the Indic shaper missed features built from them. Noto Sans
Bengali's ra-phala (e.g. গ্র) came out as consonant, visible hasant and ra.

0.13.325 Aug 20262 sources agree

This release matches HarfBuzz v14.3.1 , and has an MSRV (minimum supported Rust version) of 1.85.

This release matches HarfBuzz v14.3.1, and has an MSRV (minimum supported Rust version) of 1.85.

Add support for shaping legacy AAT mort tables, including
language-specific morph features (#451, #453).
Handle tuple kerning in AAT kerx tables (#452).
Fix a debug assertion for legacy kern state tables that declare more than
256 classes (#455).
Synthesize Arabic fallback GSUB lookups, including legacy Windows-1256
glyph layouts and no_std builds (#454, #456).
Update read-fonts to 0.43.3.

Open source →

0.13.224 Aug 20262 sources agree

This release matches HarfBuzz v14.3.1 , and has an MSRV (minimum supported Rust version) of 1.85.

This release matches HarfBuzz v14.3.1, and has an MSRV (minimum supported Rust version) of 1.85.

Speed up contextual and chained-context lookup matching by probing raw rule
offsets and reusing parsed coverage tables (#437).
Skip the redundant per-subtable digest test for single-subtable lookups
(#438).
Set up glyph-set acceleration before applying legacy kern tables (#439).
Precompute and pack AAT state-machine safe-to-break probes in the face cache
(#445).
Cache reusable shaping table metadata and avoid moving shaper and buffer
temporaries on every shape (#446, #447).

Open source →

0.13.121 Aug 20262 sources agree

This release matches HarfBuzz v14.3.1 , and has an MSRV (minimum supported Rust version) of 1.85.

This release matches HarfBuzz v14.3.1, and has an MSRV (minimum supported Rust version) of 1.85.

Saturate shaping and positioning math across GPOS, kerx, trak, fallback,
shaping, metrics, and font scaling paths to avoid overflow and better match
HarfBuzz behavior (#420).
Cache GDEF mark filtering sets in bitmaps (#421).
Lock icu_properties to 2.2.0 (#422).
Optimize hot loops in contextual and layout matching by probing rules before
parsing, hoisting invariants, moving recursion state instead of cloning, and
replacing per-element copies with block copies (#423, #424, #425).
Optimize buffer internals by copying small counts inline and charging
move_to operations against max_ops (#426, #429).
Improve AAT shaping performance by walking morx subtables through packed
descriptors, resolving subtable kinds from cached parts, and adding a
state-machine fast path (#428, #430, #431).
Skip the post-morx digest update when GPOS is not present (#433).
Add a batched nominal-glyph callback to FontFuncs (#434).
Update read-fonts to 0.43.2 (#432, #435).

Open source →

0.13.013 Aug 20262 sources agree

This release matches HarfBuzz v14.3.1 , and has an MSRV (minimum supported Rust version) of 1.85.

This release matches HarfBuzz v14.3.1, and has an MSRV (minimum supported Rust version) of 1.85.

Guard GPOS cursive attachment against out-of-bounds attach_chain offsets
that could panic on buffers longer than 32767 glyphs (#411).
Apply calt to non-Hangul characters in Hangul runs while continuing to
suppress it for Jamo.
Preserve the correct component assignments when MultipleSubst output is
ligated and positioned with mark attachment lookups.
Apply cross-direction mark attachment offsets immediately.
Bound syllables to 64 glyphs during shaping.
Map the collective ISO 15924 Hrkt script to the OpenType kana script tag.
Update read-fonts to 0.43.0 (#418).

Open source →

0.12.03 Jul 20262 sources agree

This release matches HarfBuzz v14.2.0 , and has an MSRV (minimum supported Rust version) of 1.85.

This release matches HarfBuzz v14.2.0,
and has an MSRV (minimum supported Rust version) of 1.85.

Update read-fonts to 0.41.0 (#403).
Saturate AAT kerning position accumulation to avoid overflow (#400).
Regenerate the Unicode data tables with the latest packtab (#401).
Keep GPOS variation-index deltas fractional to match HarfBuzz, avoiding
sub-font-unit advance and placement differences on variable fonts (#403).
Keep AAT trak tracking fractional to match HarfBuzz (#404).

Open source →

0.11.029 Jun 20262 sources agree

This release matches HarfBuzz v14.2.0 , and has an MSRV (minimum supported Rust version) of 1.85.

This release matches HarfBuzz v14.2.0,
and has an MSRV (minimum supported Rust version) of 1.85.

Parse contextual lookup rules in a single pass in the apply path for improved performance (#383).
Fix integer overflow in fallback positioning shaper (#395).
Fix overflow panic in skipping_iterator_t when shaping extremely long lines (#397).
Fix custom nominal glyph cmap caching (#399).

Open source →

0.10.020 Jun 20262 sources agree

This release matches HarfBuzz v14.2.0 , and has an MSRV (minimum supported Rust version) of 1.85.

This release matches HarfBuzz v14.2.0,
and has an MSRV (minimum supported Rust version) of 1.85.

Add support for the new read-fonts Font API behind the experimental_font_api
feature flag in both read-fonts and harfrust, and update read-fonts to 0.40.2.
Reject recursive extension lookups.
Bound ligature cache construction.

Open source →

0.9.015 Jun 20262 sources agree

This release matches HarfBuzz v14.2.0 , and has an MSRV (minimum supported Rust version) of 1.85.

This release matches HarfBuzz v14.2.0,
and has an MSRV (minimum supported Rust version) of 1.85.

Fix GPOS attachment offset overflow #384
Require read-fonts 0.40.

Open source →

0.8.42 Jun 20262 sources agree

This release matches HarfBuzz v14.2.0 , and has an MSRV (minimum supported Rust version) of 1.85.

This release matches HarfBuzz v14.2.0,
and has an MSRV (minimum supported Rust version) of 1.85.

Use bytes instead of str storage for language tag table.

Open source →

0.8.31 Jun 20262 sources agree

This release matches HarfBuzz v14.2.0 , and has an MSRV (minimum supported Rust version) of 1.85.

This release matches HarfBuzz v14.2.0,
and has an MSRV (minimum supported Rust version) of 1.85.

Add method for appending bulk glyph infos to UnicodeBuffer.

Open source →

0.8.21 Jun 2026Breaking2 sources agree

Reify glyph flags into a GlyphFlags type. Existing methods on GlyphInfo remain for now to avoid a breaking change but will be removed in a future vers…