5.1.0

• More extensive buffer tracing messages. (Behdad Esfahbod)

• Fix hb-ft regression in bitmap fonts rendering. (Behdad Esfahbod)

• Support extension promotion of lookups in hb-subset-repacker. (Garret Rieger)

• A new HB_GLYPH_FLAG_SAFE_TO_INSERT_TATWEEL for scripts that use elongation (e.g. Arabic) to signify where it is safe to insert tatweel glyph without interrupting shaping. (Behdad Esfahbod)

• Add --safe-to-insert-tatweel to hb-shape tool. (Behdad Esfahbod)

• New API
  +HB_GLYPH_FLAG_SAFE_TO_INSERT_TATWEEL
  +HB_BUFFER_FLAG_PRODUCE_SAFE_TO_INSERT_TATWEEL

5.0.1

• Fix version 2 avar table with hb-ft. (Behdad Esfahbod)

5.0.0

• Support fonts with more than 65535 glyphs in GDEF, GSUB, and GPOS tables. This is part of boring-expansion-spec to extend OpenType in a backward-compatible way. (Behdad Esfahbod, Garret Riegerr)

• Complete support for more than 65535 glyphs in glyf table that started in 4.0.0 release. Part of boring-expansion-spec. (Behdad Esfahbod)

• Support version 2 of avar table. Part of boring-expansion-spec. (Behdad Esfahbod)

• Fix mark attachment on multiple substitutions in some cases. (Behdad Esfahbod)

• Fix application of calt, rclt, and ccmp features to better match Uniscribe behaviour with some Arabic fonts. (Behdad Esfahbod)

• Improvement to interaction between multiple cursive attachments. (Behdad Esfahbod)

• Improve multiple mark interactions in Hebrew. (Behdad Esfahbod)

• Implement language-specific forms in AAT shaping. (Behdad Esfahbod)

• Fix variation of VORG table. (Behdad Esfahbod)

• Support for specific script tags to be retained in the subsetter, and add --layout-scripts option to hb-subset tool. (Garret Rieger)

• Accept space as delimiter for --features/--variations in command line tools. (Behdad Esfahbod)

• Improve subsetting of COLR table. (Qunxin Liu)

• Improved fuzzing coverage for ot-math API. (Frédéric Wang)

• Fix kern table version 2 (AAT) sanitization on 32-bit systems. (Behdad Esfahbod)

• Allow negative glyph advances from graphite2 shaper. (Stephan Bergmann)

• Implement loading (color) bitmap fonts with hb-ft. (Behdad Esfahbod)

• Fix regression in hb-ft when changing font size. (Behdad Esfahbod)

• Fix build on GCC < 7. (Kleis Auke Wolthuizen)

• Dynamically load dwrite.dll on windows if directwrite shaper is enabled. (Luca Bacci)

• Provide a single-file harfbuzz-subset.cc file for easier alternate building of hb-subset library, similar to harfbuzz.cc. (Khaled Hosny)

• New API
  +HB_SUBSET_SETS_LAYOUT_SCRIPT_TAG
  +hb_language_matches()

4.4.1

• Fix test failure with some compilers.
• Fix Telugu and Kannada kerning regression.

4.4.0

• Caching of variable fonts shaping, in particular when using HarfBuzz’s own font loading functions (ot). Bringing performance of variable shaping in par with non-variable fonts shaping. (Behdad Esfahbod)

• Caching of format 2 “Contextual Substitution” and “Chained Contexts Substitution” lookups. Resulting in up to 20% speedup of lookup-heavy fonts like Gulzar or Noto Nastaliq Urdu. (Behdad Esfahbod)

• Improved ANSI output from hb-view. (Behdad Esfahbod)

• Support for shaping legacy, pre-OpenType, Windows 3.1-era, Arabic fonts that relied on a fixed PUA encoding. (Khaled Hosny, Behdad Esfahbod)

• Sinhala script is now shaped by the USE shaper instead of “indic” one. (Behdad Esfahbod, David Corbett)

• Thai shaper improvements. (David Corbett)

• hb-ot-name API supports approximate BCP-47 language matching, for example asking for “en_US” in a font that has only “en” names will return them. (Behdad Esfahbod)

• Optimized TrueType glyph shape loading. (Behdad Esfahbod)

• Fix subsetting of HarfBuzz faces created via hb_face_create_for_tables(). (Garret Rieger)

• Add 32 bit var store support to the subsetter. (Garret Rieger)

• New API
  +HB_BUFFER_FLAG_DEFINED
  +HB_BUFFER_SERIALIZE_FLAG_DEFINED
  +hb_font_changed()
  +hb_font_get_serial()
  +hb_ft_hb_font_changed()
  +hb_set_hash()
  +hb_map_copy()
  +hb_map_hash()

4.3.0

• Major speed up in loading and subsetting fonts, especially in handling CFF table. Subsetting some fonts is now 3 times faster. (Behdad Esfahbod, Garret Rieger)

• Speed up blending CFF2 table. (Behdad Esfahbod)

• Speed up hb_ot_tags_from_language(). (Behdad Esfahbod, David Corbett)

• Fix USE classification of U+10A38 to fix multiple marks on single Kharoshthi base. (David Corbett)

• Fix parsing of empty CFF Index. (Behdad Esfahbod)

• Fix subsetting CPAL table with partial palette overlaps. (Garret Rieger)

• New API
  +hb_map_is_equal() (Behdad Esfahbod)

4.2.1

• Make sure hb_blob_create_from_file_or_fail() always returns nullptr in case of failure and not empty blob sometimes. (Khaled Hosny)
• Add --passthrough-tables option to hb-subset. (Cosimo Lupo)
• Reinstate a pause after basic features in Khmer shaper, fixing a regression introduced in previous release. (Behdad Esfahbod)
• Better handling of Regional_Indicator when shaped with RTL-native scripts, reverting earlier fix that caused regressions in AAT shaping. (Behdad Esfahbod)

4.2.0

• Source code reorganization, splitting large hb-ot-layout files into smaller, per-subtable ones under OT/Layout/*. Code for more tables will follow suit in later releases. (Garret Rieger, Behdad Esfahbod)

• Revert Indic shaper change in previous release that broke some fonts and instead make per-syllable restriction of “GSUB” application limited to script-specific Indic features, while applying them and discretionary features in one go. (Behdad Esfahbod)

• Fix decoding of private in gvar table. (Behdad Esfahbod)

• Fix handling of contextual lookups that delete too many glyphs. (Behdad Esfahbod)

• Make “morx” deleted glyphs don’t block “GPOS” application. (Behdad Esfahbod)

• Various build fixes. (Chun-wei Fan, Khaled Hosny)

• New API
  +hb_set_next_many() (Andrew John)

4.1.0

• Various OSS-Fuzz fixes. (Behdad Esfahbod)

• Make fallback vertical-origin match FreeType’s. (Behdad Esfahbod)

• Treat visible viramas like dependent vowels in USE shaper. (David Corbett)

• Apply presentation forms features and discretionary features in one go in Indic shaper, which seems to match Uniscribe and CoreText behaviour. (Behdad Esfahbod, David Corbett)

• Various bug fixes.

• New API
  +hb_set_add_sorted_array() (Andrew John)

4.0.1

• Update OpenType to AAT mappings for hist and vrtr features. (Florian Pircher)

• Update IANA Language Subtag Registry to 2022-03-02. (David Corbett)

• Update USE shaper to allow any non-numeric tail in a symbol cluster, and remove obsolete data overrides. (David Corbett)

• Fix handling of baseline variations to return correctly scaled values. (Matthias Clasen)

• A new experimental hb_subset_repack_or_fail() to repack an array of objects, eliminating offset overflows. The API is not available unless HarfBuzz is built with experimental APIs enabled. (Qunxin Liu)

• New experimental API
  +hb_link_t
  +hb_object_t
  +hb_subset_repack_or_fail()