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Member "firefox-69.0.1/gfx/harfbuzz/NEWS" (17 Sep 2019, 67760 Bytes) of package /linux/www/firefox-69.0.1.source.tar.xz:


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    1 Overview of changes leading to 2.5.3
    2 Wednesday, June 26, 2019
    3 ====================================
    4 - Fix UCD script data for Unicode 10+ scripts.  This was broken since 2.5.0.
    5 - More optimizations for HB_TINY.
    6 
    7 
    8 Overview of changes leading to 2.5.2
    9 Thursday, June 20, 2019
   10 ====================================
   11 - More hb-config.hh facilities to shrink library size, namely when built as
   12   HB_TINY.
   13 - New documentation of custom configurations in CONFIG.md.
   14 - Fix build on gcc 4.8.  That's supported again.
   15 - Universal Shaping Engine improvements thanks to David Corbett.
   16 - API Changes: Undeprecate some horizontal-kerning API and re-enable in hb-ft,
   17   such that Type1 fonts will continue kerning.
   18 
   19 
   20 Overview of changes leading to 2.5.1
   21 Friday, May 31, 2019
   22 ====================================
   23 - Fix build with various versions of Visual Studio.
   24 - Improved documentation, thanks to Nathan Willis.
   25 - Bugfix in subsetting glyf table.
   26 - Improved scripts for cross-compiling for Windows using mingw.
   27 - Rename HB_MATH_GLYPH_PART_FLAG_EXTENDER to HB_OT_MATH_GLYPH_PART_FLAG_EXTENDER.
   28   A deprecated macro is added for backwards-compatibility.
   29 
   30 
   31 Overview of changes leading to 2.5.0
   32 Friday, May 24, 2019
   33 ====================================
   34 - This release does not include much functional changes, but includes major internal
   35   code-base changes.  We now require C++11.  Support for gcc 4.8 and earlier has been
   36   dropped.
   37 - New hb-config.hh facility for compiling smaller library for embedded and web usecases.
   38 - New Unicode Character Databse implementation that is half the size of previously-used
   39   UCDN.
   40 - Subsetter improvements.
   41 - Improved documentation, thanks to Nathan Willis.
   42 - Misc shaping fixes.
   43 
   44 
   45 Overview of changes leading to 2.4.0
   46 Monday, March 25, 2019
   47 ====================================
   48 - Unicode 12.
   49 - Misc fixes.
   50 - Subsetter improvements.
   51 - New API:
   52 HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE
   53 hb_directwrite_face_create()
   54 
   55 
   56 Overview of changes leading to 2.3.1
   57 Wednesday, January 30, 2019
   58 ====================================
   59 - AAT bug fixes.
   60 - Misc internal housekeeping cleanup.
   61 
   62 
   63 Overview of changes leading to 2.3.0
   64 Thursday, December 20, 2018
   65 ====================================
   66 - Fix regression on big-endian architectures.  Ouch!
   67 - Misc bug and build fixes.
   68 - Fix subsetting of simple GSUB/GDEF.
   69 - Merge CFF / CFF2 support contributed by Adobe.  This mostly involves
   70   the subsetter, but also get_glyph_extents on CFF fonts.
   71 
   72 New API in hb-aat.h:
   73 +hb_aat_layout_has_substitution()
   74 +hb_aat_layout_has_positioning()
   75 +hb_aat_layout_has_tracking()
   76 
   77 
   78 Overview of changes leading to 2.2.0
   79 Thursday, November 29, 2018
   80 ====================================
   81 - Misc shaping bug fixes.
   82 - Add font variations named-instance API.
   83 - Deprecate font variations axis enumeration API and add replacement.
   84 - AAT shaping improvements:
   85   o Fixed 'kern' table Format 2 implementation.
   86   o Implement 'feat' table API for feature detection.
   87   o Blacklist 'GSUB' table of fonts from 'MUTF' foundry that also have 'morx'.
   88 
   89 New API:
   90 +hb_aat_layout_feature_type_t
   91 +hb_aat_layout_feature_selector_t
   92 +hb_aat_layout_get_feature_types()
   93 +hb_aat_layout_feature_type_get_name_id
   94 +hb_aat_layout_feature_selector_info_t
   95 +HB_AAT_LAYOUT_NO_SELECTOR_INDEX
   96 +hb_aat_layout_feature_type_get_selector_infos()
   97 +hb_ot_var_axis_flags_t
   98 +hb_ot_var_axis_info_t
   99 +hb_ot_var_get_axis_infos()
  100 +hb_ot_var_find_axis_info()
  101 +hb_ot_var_get_named_instance_count()
  102 +hb_ot_var_named_instance_get_subfamily_name_id()
  103 +hb_ot_var_named_instance_get_postscript_name_id()
  104 +hb_ot_var_named_instance_get_design_coords()
  105 
  106 Deprecated API:
  107 +HB_OT_VAR_NO_AXIS_INDEX
  108 +hb_ot_var_axis_t
  109 +hb_ot_var_get_axes()
  110 +hb_ot_var_find_axis()
  111 
  112 
  113 Overview of changes leading to 2.1.3
  114 Friday, November 16, 2018
  115 ====================================
  116 - Fix AAT 'mort' shaping, which was broken in 2.1.2
  117 
  118 
  119 Overview of changes leading to 2.1.2
  120 Friday, November 16, 2018
  121 ====================================
  122 - Various internal changes.
  123 - AAT shaping improvements:
  124   o Implement kern table Format 1 state-machine-based kerning.
  125   o Implement cross-stream kerning (cursive positioning, etc).
  126   o Ignore emptyish GSUB tables (zero scripts) if morx present.
  127   o Don't apply GPOS if morx is being applied.  Matches Apple.
  128 
  129 
  130 -Overview of changes leading to 2.1.1
  131 Monday, November 5, 2018
  132 ====================================
  133 - AAT improvements:
  134   o Implement 'mort' table.
  135   o Implement 'kern' subtables Format 1 and Format 3.
  136 
  137 
  138 Overview of changes leading to 2.1.0
  139 Tuesday, October 30, 2018
  140 ====================================
  141 - AAT shaping improvements:
  142   o Allow user controlling AAT features, for whole buffer only currently.
  143   o Several 'morx' fixes.
  144   o Implement tuple-kerns in 'kerx'; Fixes kerning with Apple default
  145     San Francisco fonts.
  146 - Support for color fonts:
  147   o COLR/CPAL API to fetch color layers.
  148   o SVG table to fetch SVG documents.
  149   o CBDT/sbix API to fetch PNG images.
  150 - New 'name' table API.
  151 - hb-ot-font now uses 'VORG' table to correctly position CFF glyphs
  152   in vertical layout.
  153 - Various fuzzer-found bug fixes.
  154 
  155 Changed API:
  156 
  157 A type and a macro added in 2.0.0 were renamed:
  158 
  159 hb_name_id_t -> hb_ot_name_id_t
  160 HB_NAME_ID_INVALID -> HB_OT_NAME_ID_INVALID
  161 
  162 New API:
  163 
  164 +hb_color_t
  165 +HB_COLOR
  166 +hb_color_get_alpha()
  167 +hb_color_get_red()
  168 +hb_color_get_green()
  169 +hb_color_get_blue()
  170 +hb_ot_color_has_palettes()
  171 +hb_ot_color_palette_get_count()
  172 +hb_ot_color_palette_get_name_id()
  173 +hb_ot_color_palette_color_get_name_id()
  174 +hb_ot_color_palette_flags_t
  175 +hb_ot_color_palette_get_flags()
  176 +hb_ot_color_palette_get_colors()
  177 +hb_ot_color_has_layers()
  178 +hb_ot_color_layer_t
  179 +hb_ot_color_glyph_get_layers()
  180 +hb_ot_color_has_svg()
  181 +hb_ot_color_glyph_reference_svg()
  182 +hb_ot_color_has_png()
  183 +hb_ot_color_glyph_reference_png()
  184 
  185 +hb_ot_name_id_t
  186 +HB_OT_NAME_ID_INVALID
  187 +HB_OT_NAME_ID_COPYRIGHT
  188 +HB_OT_NAME_ID_FONT_FAMILY
  189 +HB_OT_NAME_ID_FONT_SUBFAMILY
  190 +HB_OT_NAME_ID_UNIQUE_ID
  191 +HB_OT_NAME_ID_FULL_NAME
  192 +HB_OT_NAME_ID_VERSION_STRING
  193 +HB_OT_NAME_ID_POSTSCRIPT_NAME
  194 +HB_OT_NAME_ID_TRADEMARK
  195 +HB_OT_NAME_ID_MANUFACTURER
  196 +HB_OT_NAME_ID_DESIGNER
  197 +HB_OT_NAME_ID_DESCRIPTION
  198 +HB_OT_NAME_ID_VENDOR_URL
  199 +HB_OT_NAME_ID_DESIGNER_URL
  200 +HB_OT_NAME_ID_LICENSE
  201 +HB_OT_NAME_ID_LICENSE_URL
  202 +HB_OT_NAME_ID_TYPOGRAPHIC_FAMILY
  203 +HB_OT_NAME_ID_TYPOGRAPHIC_SUBFAMILY
  204 +HB_OT_NAME_ID_MAC_FULL_NAME
  205 +HB_OT_NAME_ID_SAMPLE_TEXT
  206 +HB_OT_NAME_ID_CID_FINDFONT_NAME
  207 +HB_OT_NAME_ID_WWS_FAMILY
  208 +HB_OT_NAME_ID_WWS_SUBFAMILY
  209 +HB_OT_NAME_ID_LIGHT_BACKGROUND
  210 +HB_OT_NAME_ID_DARK_BACKGROUND
  211 +HB_OT_NAME_ID_VARIATIONS_PS_PREFIX
  212 +hb_ot_name_entry_t
  213 +hb_ot_name_list_names()
  214 +hb_ot_name_get_utf8()
  215 +hb_ot_name_get_utf16()
  216 +hb_ot_name_get_utf32()
  217 
  218 
  219 Overview of changes leading to 2.0.2
  220 Saturday, October 20, 2018
  221 ====================================
  222 - Fix two minor memory access issues in AAT tables.
  223 
  224 
  225 Overview of changes leading to 2.0.1
  226 Friday, October 19, 2018
  227 ====================================
  228 - Fix hb-version.h reported release version that went wrong (1.8.0)
  229   with previous release.
  230 - Fix extrapolation in 'trak' table.
  231 - Fix hb-font infinite-recursion issue with some font funcs and
  232   subclassed fonts.
  233 - Implement variation-kerning format in kerx table, although without
  234   variation.
  235 - Fix return value of hb_map_is_empty().
  236 
  237 
  238 Overview of changes leading to 2.0.0
  239 Thursday, October 18, 2018
  240 ====================================
  241 - Added AAT shaping support (morx/kerx/trak).
  242   Automatically used if GSUB/GPOS are not available respectively.
  243   Set HB_OPTIONS=aat env var to have morx/kerx preferred over
  244   GSUB/GPOS.
  245 - Apply TrueType kern table internally, instead of relying on
  246   hb_font_t callbacks.
  247 - Khmer shaper significantly rewritten to better match Uniscribe.
  248 - Indic3 tags ('dev3', etc) are passed to USE shaper.
  249 - .dfont Mac font containers implemented.
  250 - Script- and language-mapping revamped to better use BCP 47.
  251 - Misc USE and Indic fixes.
  252 - Misc everything fixes.
  253 - Too many things to list.  Biggest release since 0.9.1, with
  254   over 500 commits in just over 5 weeks!  Didn't intend it to
  255   be a big release.  Just happened to become.
  256 - hb-ft now locks underlying FT_Face during use.
  257 
  258 API changes:
  259 
  260 - Newly-created hb_font_t's now have our internal "hb-ot-font"
  261   callbacks set on them, so they should work out of the box
  262   without any callbacks set.  If callbacks are set, everything
  263   is back to what it was before, the fallback callbacks are
  264   null.  If you to get the internal implementation modified,
  265   sub_font it.
  266 
  267 - New hb_font_funcs_set_nominal_glyphs_func() allows speeding
  268   up character to glyph mapping.
  269 
  270 New API:
  271 +HB_FEATURE_GLOBAL_START
  272 +HB_FEATURE_GLOBAL_END
  273 +hb_buffer_set_invisible_glyph()
  274 +hb_buffer_get_invisible_glyph()
  275 +hb_font_funcs_set_nominal_glyphs_func()
  276 +hb_ot_layout_table_select_script()
  277 +hb_ot_layout_script_select_language()
  278 +hb_ot_layout_feature_get_name_ids()
  279 +hb_ot_layout_feature_get_characters()
  280 +hb_name_id_t
  281 +HB_NAME_ID_INVALID
  282 +HB_OT_MAX_TAGS_PER_SCRIPT
  283 +hb_ot_tags_from_script_and_language()
  284 +hb_ot_tags_to_script_and_language()
  285 
  286 Deprecated API:
  287 -hb_font_funcs_set_glyph_func()
  288 -hb_unicode_eastasian_width_func_t
  289 -hb_unicode_funcs_set_eastasian_width_func()
  290 -hb_unicode_eastasian_width()
  291 -hb_unicode_decompose_compatibility_func_t
  292 -HB_UNICODE_MAX_DECOMPOSITION_LEN
  293 -hb_unicode_funcs_set_decompose_compatibility_func()
  294 -hb_unicode_decompose_compatibility()
  295 -hb_font_funcs_set_glyph_h_kerning_func()
  296 -hb_font_funcs_set_glyph_v_kerning_func()
  297 -hb_font_get_glyph_h_kerning()
  298 -hb_font_get_glyph_v_kerning()
  299 -hb_font_get_glyph_kerning_for_direction()
  300 -hb_ot_layout_table_choose_script()
  301 -hb_ot_layout_script_find_language()
  302 -hb_ot_tags_from_script()
  303 -hb_ot_tag_from_language()
  304 
  305 
  306 Overview of changes leading to 1.9.0
  307 Monday, September 10, 2018
  308 ====================================
  309 - Added 'cmap' API to hb_face_t.
  310 - Face-builder API.
  311 - hb-ot-font re-creation should be much leaner now, as the
  312   font tables it uses are cached on hb_face_t now.
  313 - Internal source header file name changes:
  314   hb-*-private.hh is renamed to hb-*.hh.
  315 
  316 New API:
  317 +HB_UNICODE_MAX
  318 +hb_face_collect_unicodes()
  319 +hb_face_collect_variation_selectors()
  320 +hb_face_collect_variation_unicodes()
  321 +hb_face_builder_create()
  322 +hb_face_builder_add_table()
  323 
  324 
  325 Overview of changes leading to 1.8.8
  326 Tuesday, August 14, 2018
  327 ====================================
  328 - Fix hb-icu crash on architectures where compare_exchange_weak() can
  329   fail falsely.  This bug was introduced in 1.8.4.
  330   https://bugs.chromium.org/p/chromium/issues/detail?id=873568
  331 - More internal refactoring of atomic operations and singletons.
  332 - API changes:
  333   The following functions do NOT reference their return value before
  334   returning:
  335   * hb_unicode_funcs_get_default()
  336   * hb_glib_get_unicode_funcs()
  337   * hb_icu_get_unicode_funcs()
  338   This is consistent with their naming ("get", instead of "reference")
  339   as well as how they are used in the wild (ie. no one calls destroy()
  340   on their return value.)
  341 
  342 
  343 Overview of changes leading to 1.8.7
  344 Wednesday, August 8, 2018
  345 ====================================
  346 - Fix assertion failure with GDEF-blacklisted fonts.
  347 
  348 
  349 Overview of changes leading to 1.8.6
  350 Tuesday, August 7, 2018
  351 ====================================
  352 - Internal code shuffling.
  353 - New API to speed up getting advance widths for implementations
  354   that have heavy overhead in get_h_advance callback:
  355 +hb_font_funcs_set_glyph_h_advances_func
  356 +hb_font_funcs_set_glyph_v_advances_func
  357 +hb_font_get_glyph_advances_for_direction
  358 +hb_font_get_glyph_h_advances
  359 +hb_font_get_glyph_h_advances_func_t
  360 +hb_font_get_glyph_v_advances
  361 +hb_font_get_glyph_v_advances_func_t
  362 
  363 
  364 Overview of changes leading to 1.8.5
  365 Wednesday, August 1, 2018
  366 ====================================
  367 - Major Khmer shaper improvements to better match Microsoft.
  368 - Indic bug fixes.
  369 - Internal improvements to atomic operations.
  370 
  371 
  372 Overview of changes leading to 1.8.4
  373 Tuesday, July 17, 2018
  374 ====================================
  375 - Fix build on non-C++11.
  376 - Use C++-style GCC atomics and C++11 atomics.
  377 
  378 
  379 Overview of changes leading to 1.8.3
  380 Wednesday, July 11, 2018
  381 ====================================
  382 - A couple of Indic / USE bug fixes.
  383 - Disable vectorization, as it was causing unaligned access bus error on
  384   certain 32bit architectures.
  385 
  386 
  387 Overview of changes leading to 1.8.2
  388 Tuesday, July 3, 2018
  389 ====================================
  390 - Fix infinite loop in Khmer shaper.
  391 - Improve hb_blob_create_from_file() for streams.
  392 
  393 
  394 Overview of changes leading to 1.8.1
  395 Tuesday, June 12, 2018
  396 ====================================
  397 - Fix hb-version.h file generation; last two releases went out with wrong ones.
  398 - Add correctness bug in hb_set_t operations, introduced in 1.7.7.
  399 - Remove HB_SUBSET_BUILTIN build option.  Not necessary.
  400 
  401 
  402 Overview of changes leading to 1.8.0
  403 Tuesday, June 5, 2018
  404 ====================================
  405 - Update to Unicode 11.0.0.
  406 
  407 
  408 Overview of changes leading to 1.7.7
  409 Tuesday, June 5, 2018
  410 ====================================
  411 - Lots of internal changes, but not yet exposed externally.
  412 - All HarfBuzz objects are significantly smaller in size now.
  413 - Sinhala: Position repha on top of post-consonant, not base.
  414   This better matches Windows 10 behavior, which was changed
  415   from previous Windows versions.
  416 - New build options:
  417   o New cpp macro HB_NO_ATEXIT
  418   o New cpp macro HB_SUBSET_BUILTIN
  419 - Significant libharfbuzz-subset changes. API subject to change.
  420 - New API in libharfbuzz:
  421 
  422 +hb_blob_create_from_file()
  423 +hb_face_count()
  424 
  425 A hashmap implementation:
  426 +hb-map.h
  427 +HB_MAP_VALUE_INVALID
  428 +hb_map_t
  429 +hb_map_create()
  430 +hb_map_get_empty()
  431 +hb_map_reference()
  432 +hb_map_destroy()
  433 +hb_map_set_user_data()
  434 +hb_map_get_user_data()
  435 +hb_map_allocation_successful()
  436 +hb_map_clear()
  437 +hb_map_is_empty()
  438 +hb_map_get_population()
  439 +hb_map_set()
  440 +hb_map_get()
  441 +hb_map_del()
  442 +hb_map_has()
  443 
  444 
  445 Overview of changes leading to 1.7.6
  446 Wednesday, March 7, 2018
  447 ====================================
  448 
  449 - Fix to hb_set_t binary operations. Ouch.
  450 - New experimental harfbuzz-subset library. All of hb-subset.h
  451   is experimental right now and API WILL change.
  452 
  453 - New API:
  454 hb_blob_copy_writable_or_fail()
  455 HB_OT_TAG_BASE
  456 hb_set_previous()
  457 hb_set_previous_range()
  458 
  459 
  460 Overview of changes leading to 1.7.5
  461 Tuesday, January 30, 2018
  462 ====================================
  463 
  464 - Separate Khmer shaper from Indic.
  465 - First stab at AAT morx. Not hooked up.
  466 - Misc bug fixes.
  467 
  468 
  469 Overview of changes leading to 1.7.4
  470 Wednesday, December 20, 2017
  471 ====================================
  472 
  473 - Fix collect_glyphs() regression caused by hb_set_t changes.
  474 
  475 
  476 Overview of changes leading to 1.7.3
  477 Monday, December 18, 2017
  478 ====================================
  479 
  480 - hb_set_t performance tuning and optimizations.
  481 - Speed up collect_glyphs() and reject garbage data.
  482 - In hb_coretext_font_create() set font point-size (ptem).
  483 - Misc fixes.
  484 
  485 
  486 Overview of changes leading to 1.7.2
  487 Monday, December 4, 2017
  488 ====================================
  489 
  490 - Optimize hb_set_add_range().
  491 - Misc fixes.
  492 - New API:
  493 hb_coretext_font_create()
  494 
  495 
  496 Overview of changes leading to 1.7.1
  497 Tuesday, November 14, 2017
  498 ====================================
  499 
  500 - Fix atexit object destruction regression.
  501 - Fix minor integer-overflow.
  502 
  503 
  504 Overview of changes leading to 1.7.0
  505 Monday, November 13, 2017
  506 ====================================
  507 
  508 - Minor Indic fixes.
  509 - Implement kerning and glyph names in hb-ot-font.
  510 - Various DSO optimization re .data and .bss sizes.
  511 - Make C++11 optional; build fixes.
  512 - Mark all other backends "unsafe-to-break".
  513 - Graphite fix.
  514 
  515 
  516 Overview of changes leading to 1.6.3
  517 Thursday, October 26th, 2017
  518 ====================================
  519 
  520 - Fix hb_set_t some more.  Should be solid now.
  521 - Implement get_glyph_name() for hb-ot-font.
  522 - Misc fixes.
  523 
  524 
  525 Overview of changes leading to 1.6.2
  526 Monday, October 23nd, 2017
  527 ====================================
  528 
  529 - Yesterday's release had a bad crasher; don't use it.  That's what
  530   happens when one works on Sunday...
  531   https://github.com/harfbuzz/harfbuzz/issues/578
  532 - Build fixes for FreeBSD and Chrome Android.
  533 
  534 
  535 Overview of changes leading to 1.6.1
  536 Sunday, October 22nd, 2017
  537 ====================================
  538 
  539 - Don't skip over COMBINING GRAPHEME JOINER when ligating, etc.
  540   To be refined: https://github.com/harfbuzz/harfbuzz/issues/554
  541 - Faster hb_set_t implementation.
  542 - Don't use deprecated ICU API.
  543 - Fix undefined-behavior in Myanmar shaper, introduced in 1.6.0
  544 - Deprecated API:
  545   hb_set_invert()
  546 
  547 
  548 Overview of changes leading to 1.6.0
  549 Friday, October the 13th, 2017
  550 ====================================
  551 
  552 - Update to Unicode 10.
  553 
  554 - Various Indic and Universal Shaping Engine fixes as a result of
  555   HarfBuzz Hackfest with Jonathan Kew at Web Engines Hackfest at
  556   the Igalia offices in A Coruña, Spain.  Thanks Igalia for having
  557   us!
  558 
  559 - Implement Unicode Arabic Mark Ordering Algorithm UTR#53.
  560 
  561 - Implement optical sizing / tracking in CoreText backend, using
  562   new API hb_font_set_ptem().
  563 
  564 - Allow notifying hb_font_t that underlying FT_Face changed sizing,
  565   using new API hb_ft_font_changed().
  566 
  567 - More Graphite backend RTL fixes.
  568 
  569 - Fix caching of variable font shaping plans.
  570 
  571 - hb-view / hb-shape now accept following new arguments:
  572 
  573   o --unicodes: takes a list of hex numbers that represent Unicode
  574     codepoints.
  575 
  576 New API:
  577 +hb_face_get_table_tags()
  578 +hb_font_set_ptem()
  579 +hb_font_get_ptem()
  580 +hb_ft_font_changed()
  581 
  582 
  583 Overview of changes leading to 1.5.1
  584 Tuesday, September 5, 2017
  585 ====================================
  586 
  587 - Fix "unsafe-to-break" in fallback shaping and other corner cases.
  588   All our tests pass with --verify now, meaning unsafe-to-break API
  589   works as expected.
  590 - Add --unicodes to hb-view / hb-shape.
  591 - [indic] Treat Consonant_With_Stacker as consonant.  This will need
  592   further tweaking.
  593 - hb_buffer_diff() tweaks.
  594 
  595 
  596 Overview of changes leading to 1.5.0
  597 Wednesday, August 23, 2017
  598 ====================================
  599 
  600 - Misc new API, for appending a buffer to another, and for comparing
  601   contents of two buffers for types of differences.
  602 
  603 - New "unsafe-to-break" API.  Can be used to speed up reshaping
  604   in line-breaking situations.  Essentially, after shaping, it returns
  605   positions in the input string (some of the cluster boundaries) that
  606   are "safe to break" in that if the text is segmented at that position
  607   and two sides reshaped and concatenated, the shaping result is
  608   exactly the same as shaping the text in one piece.
  609 
  610   hb-view and hb-shape and hb-shape now take --verify, which verifies
  611   the above property.
  612 
  613   Some corner cases of the implementation are still not quite working.
  614   Those will be fixed in subsequent releases.
  615 
  616 - New API:
  617 
  618 hb_buffer_append()
  619 
  620 hb_glyph_flags_t
  621 HB_GLYPH_FLAG_UNSAFE_TO_BREAK
  622 HB_GLYPH_FLAG_DEFINED
  623 hb_glyph_info_get_glyph_flags()
  624 
  625 HB_BUFFER_SERIALIZE_FLAG_GLYPH_FLAGS
  626 
  627 hb_buffer_diff_flags_t
  628 HB_BUFFER_DIFF_FLAG_EQUAL
  629 HB_BUFFER_DIFF_FLAG_CONTENT_TYPE_MISMATCH
  630 HB_BUFFER_DIFF_FLAG_LENGTH_MISMATCH
  631 HB_BUFFER_DIFF_FLAG_NOTDEF_PRESENT
  632 HB_BUFFER_DIFF_FLAG_DOTTED_CIRCLE_PRESENT
  633 HB_BUFFER_DIFF_FLAG_CODEPOINT_MISMATCH
  634 HB_BUFFER_DIFF_FLAG_CLUSTER_MISMATCH
  635 HB_BUFFER_DIFF_FLAG_GLYPH_FLAGS_MISMATCH
  636 HB_BUFFER_DIFF_FLAG_POSITION_MISMATCH
  637 hb_buffer_diff
  638 
  639 
  640 Overview of changes leading to 1.4.8
  641 Tuesday, August 8, 2017
  642 ====================================
  643 
  644 - Major fix to avar table handling.
  645 - Rename hb-shape --show-message to --trace.
  646 - Build fixes.
  647 
  648 
  649 Overview of changes leading to 1.4.7
  650 Tuesday, July 18, 2017
  651 ====================================
  652 
  653 - Multiple Indic, Tibetan, and Cham fixes.
  654 - CoreText: Allow disabling kerning.
  655 - Adjust Arabic feature order again.
  656 - Misc build fixes.
  657 
  658 
  659 Overview of changes leading to 1.4.6
  660 Sunday, April 23, 2017
  661 ====================================
  662 
  663 - Graphite2: Fix RTL positioning issue.
  664 - Backlist GDEF of more versions of Padauk and Tahoma.
  665 - New, experimental, cmake alternative build system.
  666 
  667 
  668 Overview of changes leading to 1.4.5
  669 Friday, March 10, 2017
  670 ====================================
  671 
  672 - Revert "Fix Context lookup application when moving back after a glyph..."
  673   This introduced memory access problems.  To be fixed properly soon.
  674 
  675 
  676 Overview of changes leading to 1.4.4
  677 Sunday, March 5, 2017
  678 ====================================
  679 
  680 - Fix Context lookup application when moving back after a glyph deletion.
  681 - Fix buffer-overrun in Bengali.
  682 
  683 
  684 Overview of changes leading to 1.4.3
  685 Saturday, February 25, 2017
  686 ====================================
  687 
  688 - Route Adlam script to Arabic shaper.
  689 - Misc fixes.
  690 - New API:
  691   hb_font_set_face()
  692 - Deprecate API:
  693   hb_graphite2_font_get_gr_font()
  694 
  695 
  696 Overview of changes leading to 1.4.2
  697 Monday, January 23, 2017
  698 ====================================
  699 
  700 - Implement OpenType Font Variation tables avar/fvar/HVAR/VVAR.
  701 - hb-shape and hb-view now accept --variations.
  702 - New API:
  703 
  704 hb_variation_t
  705 hb_variation_from_string()
  706 hb_variation_to_string()
  707 
  708 hb_font_set_variations()
  709 hb_font_set_var_coords_design()
  710 hb_font_get_var_coords_normalized()
  711 
  712 hb-ot-var.h:
  713 hb_ot_var_axis_t
  714 hb_ot_var_has_data()
  715 hb_ot_var_get_axis_count()
  716 hb_ot_var_get_axes()
  717 hb_ot_var_find_axis()
  718 hb_ot_var_normalize_variations()
  719 hb_ot_var_normalize_coords()
  720 
  721 - MVAR to be implemented later.  Access to named instances to be
  722   implemented later as well.
  723 
  724 - Misc fixes.
  725 
  726 
  727 Overview of changes leading to 1.4.1
  728 Thursday, January 5, 2017
  729 ====================================
  730 
  731 - Always build and use UCDN for Unicode data by default.
  732   Reduces dependence on version of Unicode data in glib,
  733   specially in the Windows bundles we are shipping, which
  734   have very old glib.
  735 
  736 
  737 Overview of changes leading to 1.4.0
  738 Thursday, January 5, 2017
  739 ====================================
  740 
  741 - Merged "OpenType GX" branch which adds core of support for
  742   OpenType 1.8 Font Variations.  To that extent, the relevant
  743   new API is:
  744 
  745 New API:
  746 hb_font_set_var_coords_normalized()
  747 
  748   with supporting API:
  749 
  750 New API:
  751 HB_OT_LAYOUT_NO_VARIATIONS_INDEX
  752 hb_ot_layout_table_find_feature_variations()
  753 hb_ot_layout_feature_with_variations_get_lookups()
  754 hb_shape_plan_create2()
  755 hb_shape_plan_create_cached2()
  756 
  757   Currently variations in GSUB/GPOS/GDEF are fully supported,
  758   and no other tables are supported.  In particular, fvar/avar
  759   are NOT supported, hence the hb_font_set_var_coords_normalized()
  760   taking normalized coordinates.  API to take design coordinates
  761   will be added in the future.
  762 
  763   HVAR/VVAR/MVAR support will also be added to hb-ot-font in the
  764   future.
  765 
  766 - Fix regression in GDEF glyph class processing.
  767 - Add decompositions for Chakma, Limbu, and Balinese in USE shaper.
  768 - Misc fixes.
  769 
  770 
  771 Overview of changes leading to 1.3.4
  772 Monday, December 5, 2016
  773 ====================================
  774 
  775 - Fix vertical glyph origin in hb-ot-font.
  776 - Implement CBDT/CBLC color font glyph extents in hb-ot-font.
  777 
  778 
  779 Overview of changes leading to 1.3.3
  780 Wednesday, September 28, 2016
  781 ====================================
  782 
  783 - Implement parsing of OpenType MATH table.
  784 New API:
  785 HB_OT_TAG_MATH
  786 HB_OT_MATH_SCRIPT
  787 hb_ot_math_constant_t
  788 hb_ot_math_kern_t
  789 hb_ot_math_glyph_variant_t
  790 hb_ot_math_glyph_part_flags_t
  791 hb_ot_math_glyph_part_t
  792 hb_ot_math_has_data
  793 hb_ot_math_get_constant
  794 hb_ot_math_get_glyph_italics_correction
  795 hb_ot_math_get_glyph_top_accent_attachment
  796 hb_ot_math_get_glyph_kerning
  797 hb_ot_math_is_glyph_extended_shape
  798 hb_ot_math_get_glyph_variants
  799 hb_ot_math_get_min_connector_overlap
  800 hb_ot_math_get_glyph_assembly
  801 
  802 
  803 Overview of changes leading to 1.3.2
  804 Wednesday, September 27, 2016
  805 ====================================
  806 
  807 - Fix build of hb-coretext on older OS X versions.
  808 
  809 
  810 Overview of changes leading to 1.3.1
  811 Wednesday, September 7, 2016
  812 ====================================
  813 
  814 - Blacklist bad GDEF of more fonts (Padauk).
  815 - More CoreText backend crash fixes with OS X 10.9.5.
  816 - Misc fixes.
  817 
  818 
  819 Overview of changes leading to 1.3.0
  820 Thursday, July 21, 2016
  821 ====================================
  822 
  823 - Update to Unicode 9.0.0
  824 - Move Javanese from Indic shaper to Universal Shaping Engine.
  825 - Allow MultipleSubst to delete a glyph (matching Windows engine).
  826 - Update Universal Shaping Engine to latest draft from Microsoft.
  827 - DirectWrite backend improvements.  Note: this backend is for testing ONLY.
  828 - CoreText backend improvements with unreachable fonts.
  829 - Implement symbol fonts (cmap 3.0.0) in hb-ft and hb-ot-font.
  830 - Blacklist bad GDEF of more fonts (Tahoma & others).
  831 - Misc fixes.
  832 
  833 
  834 Overview of changes leading to 1.2.7
  835 Monday, May 2, 2016
  836 ====================================
  837 
  838 - Blacklist another version of Times New Roman (Bold) Italic from Windows 7.
  839 - Fix Mongolian Free Variation Selectors shaping with certain fonts.
  840 - Fix Tibetan shorthand contractions shaping.
  841 - Improved list of language tag mappings.
  842 - Unbreak build on Windows CE.
  843 - Make 'glyf' table loading lazy in hb-ot-font.
  844 
  845 
  846 Overview of changes leading to 1.2.6
  847 Friday, April 8, 2016
  848 ====================================
  849 
  850 - Blacklist GDEF table of another set of Times New Roman (Bold) Italic.
  851 - DirectWrite backend improvements.  Note: DirectWrite backend is
  852   exclusively for our internal testing and should NOT be used in any
  853   production system whatsoever.
  854 
  855 
  856 Overview of changes leading to 1.2.5
  857 Monday, April 4, 2016
  858 ====================================
  859 
  860 - Fix GDEF mark-filtering-set, which was broken in 1.2.3.
  861 
  862 
  863 Overview of changes leading to 1.2.4
  864 Thursday, March 17, 2016
  865 ====================================
  866 
  867 - Synthesize GDEF glyph class for any glyph that does not have one in GDEF.
  868   I really hope we don't discover broken fonts that shape badly with this
  869   change.
  870 - Misc build and other minor fixes.
  871 - API changes:
  872   - Added HB_NDEBUG.  It's fine for production systems to define this to
  873     disable high-overhead debugging checks.  However, I also reduced the
  874     overhead of those checks, so it's a non-issue right now.  You can
  875     forget it.  Just not defining anything at all is fine.
  876 
  877 
  878 Overview of changes leading to 1.2.3
  879 Thursday, February 25, 2016
  880 ====================================
  881 
  882 - Blacklist GDEF table of certain versions of Times New Roman (Bold) Italic,
  883   due to bug in glyph class of ASCII double-quote character.  This should
  884   address "regression" introduced in 1.2.0 when we switched mark zeroing
  885   in most shapers from BY_UNICODE_LATE to BY_GDEF_LATE.
  886   This fourth release in a week should finally stablize things...
  887 
  888 - hb-ot-font's get_glyph() implementation saw some optimizations.  Though,
  889   might be really hard to measure in real-world situations.
  890 
  891 - Also, two rather small API changes:
  892 
  893 We now disable some time-consuming internal bookkeeping if built with NDEBUG
  894 defined.  This is a first time that we use NDEBUG to disable debug code.  If
  895 there exist production systems that do NOT want to enable NDEBUG, please let
  896 me know and I'll add HB_NDEBUG.
  897 
  898 Added get_nominal_glyph() and get_variation_glyph() instead of get_glyph()
  899 
  900 New API:
  901 - hb_font_get_nominal_glyph_func_t
  902 - hb_font_get_variation_glyph_func_t
  903 - hb_font_funcs_set_nominal_glyph_func()
  904 - hb_font_funcs_set_variation_glyph_func()
  905 - hb_font_get_nominal_glyph()
  906 - hb_font_get_variation_glyph()
  907 
  908 Deprecated API:
  909 - hb_font_get_glyph_func_t
  910 - hb_font_funcs_set_glyph_func()
  911 
  912 Clients that implement their own font-funcs are encouraged to replace
  913 their get_glyph() implementation with a get_nominal_glyph() and
  914 get_variation_glyph() pair.  The variation version can assume that
  915 variation_selector argument is not zero.  Old (deprecated) functions
  916 will continue working indefinitely using internal gymnastics; it is
  917 just more efficient to use the new functions.
  918 
  919 
  920 Overview of changes leading to 1.2.2
  921 Wednesday, February 24, 2016
  922 ====================================
  923 
  924 - Fix regression with mark positioning with fonts that have
  925   non-zero mark advances.  This was introduced in 1.2.0 while
  926   trying to make mark and cursive attachments to work together.
  927   I have partially reverted that, so this version is much more
  928   like what we had before.  All clients who updated to 1.2.0
  929   should update to this version.
  930 
  931 
  932 Overview of changes leading to 1.2.1
  933 Tuesday, February 23, 2016
  934 ====================================
  935 
  936 - CoreText: Fix bug with wrong scale if font scale was changed later.
  937   https://github.com/libass/libass/issues/212
  938 - CoreText: Drastically speed up font initialization.
  939 - CoreText: Fix tiny leak.
  940 - Group ZWJ/ZWNJ with previous syllable under cluster-level=0.
  941   https://github.com/harfbuzz/harfbuzz/issues/217
  942 - Add test/shaping/README.md about how to add tests to the suite.
  943 
  944 
  945 Overview of changes leading to 1.2.0
  946 Friday, February 19, 2016
  947 ====================================
  948 
  949 - Fix various issues (hangs mostly) in case of memory allocation failure.
  950 - Change mark zeroing types of most shapers from BY_UNICODE_LATE to
  951   BY_GDEF_LATE.  This seems to be what Uniscribe does.
  952 - Change mark zeroing of USE shaper from NONE to BY_GDEF_EARLY.  That's
  953   what Windows does.
  954 - Allow GPOS cursive connection on marks, and fix the interaction with
  955   mark attachment.  This work resulted in some changes to how mark
  956   attachments work.  See:
  957   https://github.com/harfbuzz/harfbuzz/issues/211
  958   https://github.com/harfbuzz/harfbuzz/commit/86c68c7a2c971efe8e35b1f1bd99401dc8b688d2
  959 - Graphite2 shaper: improved negative advance handling (eg. Nastaliq).
  960 - Add nmake-based build system for Windows.
  961 - Minor speedup.
  962 - Misc. improvements.
  963 
  964 
  965 Overview of changes leading to 1.1.3
  966 Monday, January 11, 2016
  967 ====================================
  968 
  969 - Ported Indic shaper to Unicode 8.0 data.
  970 - Universal Shaping Engine fixes.
  971 - Speed up CoreText shaper when font fallback happens in CoreText.
  972 - Documentation improvements, thanks to Khaled Hosny.
  973 - Very rough directwrite shaper for testing, thanks to Ebrahim Byagowi.
  974 - Misc bug fixes.
  975 - New API:
  976 
  977   * Font extents:
  978       hb_font_extents_t
  979       hb_font_get_font_extents_func_t
  980       hb_font_get_font_h_extents_func_t
  981       hb_font_get_font_v_extents_func_t
  982       hb_font_funcs_set_font_h_extents_func
  983       hb_font_funcs_set_font_v_extents_func
  984       hb_font_get_h_extents
  985       hb_font_get_v_extents
  986       hb_font_get_extents_for_direction
  987 
  988   * Buffer message (aka debug):
  989       hb_buffer_message_func_t
  990       hb_buffer_set_message_func()
  991     Actual message protocol to be fleshed out later.
  992 
  993 
  994 Overview of changes leading to 1.1.2
  995 Wednesday, November 26, 2015
  996 ====================================
  997 
  998 - Fix badly-broken fallback shaper that affected terminology.
  999   https://github.com/harfbuzz/harfbuzz/issues/187
 1000 - Fix y_scaling in Graphite shaper.
 1001 - API changes:
 1002   * An unset glyph_h_origin() function in font-funcs now (sensibly)
 1003     implies horizontal origin at 0,0.  Ie, the nil callback returns
 1004     true instead of false.  As such, implementations that have a
 1005     glyph_h_origin() that simply returns true, can remove that function
 1006     with HarfBuzz >= 1.1.2.  This results in a tiny speedup.
 1007 
 1008 
 1009 Overview of changes leading to 1.1.1
 1010 Wednesday, November 24, 2015
 1011 ====================================
 1012 
 1013 - Build fixes, specially for hb-coretext.
 1014 
 1015 
 1016 Overview of changes leading to 1.1.0
 1017 Wednesday, November 18, 2015
 1018 ====================================
 1019 
 1020 - Implement 'stch' stretch feature for Syriac Abbreviation Mark.
 1021   https://github.com/harfbuzz/harfbuzz/issues/141
 1022 - Disable use of decompose_compatibility() callback.
 1023 - Implement "shaping" of various Unicode space characters, even
 1024   if the font does not support them.
 1025   https://github.com/harfbuzz/harfbuzz/issues/153
 1026 - If font does not support U+2011 NO-BREAK HYPHEN, fallback to
 1027   U+2010 HYPHEN.
 1028 - Changes resulting from libFuzzer continuous fuzzing:
 1029   * Reject font tables that need more than 8 edits,
 1030   * Bound buffer growth during shaping to 32x,
 1031   * Fix assertions and other issues at OOM / buffer max-growth.
 1032 - Misc fixes and optimizations.
 1033 - API changes:
 1034   * All fonts created with hb_font_create() now inherit from
 1035     (ie. have parent) hb_font_get_empty().
 1036 
 1037 
 1038 Overview of changes leading to 1.0.6
 1039 Thursday, October 15, 2015
 1040 ====================================
 1041 
 1042 - Reduce max nesting level in OT lookups from 8 to 6.
 1043   Should not affect any real font as far as I know.
 1044 - Fix memory access issue in ot-font.
 1045 - Revert default load-flags of fonts created using hb_ft_font_create()
 1046   back to FT_LOAD_DEFAULT|FT_LOAD_NO_HINTING.  This was changed in
 1047   last release (1.0.5), but caused major issues, so revert.
 1048   https://github.com/harfbuzz/harfbuzz/issues/143
 1049 
 1050 
 1051 Overview of changes leading to 1.0.5
 1052 Tuesday, October 13, 2015
 1053 ====================================
 1054 
 1055 - Fix multiple memory access bugs discovered using libFuzzer.
 1056   https://github.com/harfbuzz/harfbuzz/issues/139
 1057   Everyone should upgrade to this version as soon as possible.
 1058   We now have continuous fuzzing set up, to avoid issues like
 1059   these creeping in again.
 1060 - Misc fixes.
 1061 
 1062 - New API:
 1063   * hb_font_set_parent().
 1064   * hb_ft_font_[sg]et_load_flags()
 1065     The default flags for fonts created using hb_ft_font_create()
 1066     has changed to default to FT_LOAD_DEFAULT now.  Previously it
 1067     was defaulting to FT_LOAD_DFEAULT|FT_LOAD_NO_HINTING.
 1068 
 1069 - API changes:
 1070   * Fonts now default to units-per-EM as their scale, instead of 0.
 1071   * hb_font_create_sub_font() does NOT make parent font immutable
 1072     anymore.  hb_font_make_immutable() does.
 1073 
 1074 
 1075 Overview of changes leading to 1.0.4
 1076 Wednesday, September 30, 2015
 1077 ====================================
 1078 
 1079 - Fix minor out-of-bounds read error.
 1080 
 1081 
 1082 Overview of changes leading to 1.0.3
 1083 Tuesday, September 1, 2015
 1084 ====================================
 1085 
 1086 - Start of user documentation, from Simon Cozens!
 1087 - Implement glyph_extents() for TrueType fonts in hb-ot-font.
 1088 - Improve GPOS cursive attachments with conflicting lookups.
 1089 - More fixes for cluster-level = 1.
 1090 - Uniscribe positioning fix.
 1091 
 1092 
 1093 Overview of changes leading to 1.0.2
 1094 Wednesday, August 19, 2015
 1095 ====================================
 1096 
 1097 - Fix shaping with cluster-level > 0.
 1098 - Fix Uniscribe backend font-size scaling.
 1099 - Declare dependencies in harfbuzz.pc.
 1100   FreeType is not declared though, to avoid bugs in pkg-config
 1101   0.26 with recursive dependencies.
 1102 - Slightly improved debug infrastructure.  More to come later.
 1103 - Misc build fixes.
 1104 
 1105 
 1106 Overview of changes leading to 1.0.1
 1107 Monday, July 27, 2015
 1108 ====================================
 1109 
 1110 - Fix out-of-bounds access in USE shaper.
 1111 
 1112 
 1113 Overview of changes leading to 1.0.0
 1114 Sunday, July 26, 2015
 1115 ====================================
 1116 
 1117 - Implement Universal Shaping Engine:
 1118   https://www.microsoft.com/typography/OpenTypeDev/USE/intro.htm
 1119   http://blogs.windows.com/bloggingwindows/2015/02/23/windows-shapes-the-worlds-languages/
 1120 - Bump version to 1.0.0.  The soname was NOT bumped.
 1121 
 1122 
 1123 Overview of changes leading to 0.9.42
 1124 Thursday, July 26, 2015
 1125 =====================================
 1126 
 1127 - New API to allow for retrieving finer-grained cluster
 1128   mappings if the client desires to handle them.  Default
 1129   behavior is unchanged.
 1130 - Fix cluster merging when removing default-ignorables.
 1131 - Update to Unicode 8.0
 1132 - hb-graphite2 fixes.
 1133 - Misc fixes.
 1134 - Removed HB_NO_MERGE_CLUSTERS hack.
 1135 - New API:
 1136   hb_buffer_cluster_level_t enum
 1137   hb_buffer_get_cluster_level()
 1138   hb_buffer_set_cluster_level()
 1139   hb-shape / hb-view --cluster-level
 1140 
 1141 
 1142 Overview of changes leading to 0.9.41
 1143 Thursday, June 18, 2015
 1144 =====================================
 1145 
 1146 - Fix hb-coretext with trailing whitespace in right-to-left.
 1147 - New API: hb_buffer_reverse_range().
 1148 - Allow implementing atomic ops in config.h.
 1149 - Fix hb_language_t in language bindings.
 1150 - Misc fixes.
 1151 
 1152 
 1153 Overview of changes leading to 0.9.40
 1154 Friday, March 20, 2015
 1155 =====================================
 1156 
 1157 - Another hb-coretext crasher fix.  Ouch!
 1158 - Happy Norouz!
 1159 
 1160 
 1161 Overview of changes leading to 0.9.39
 1162 Wednesday, March 4, 2015
 1163 =====================================
 1164 
 1165 - Critical hb-coretext fixes.
 1166 - Optimizations and refactoring; no functional change
 1167   expected.
 1168 - Misc build fixes.
 1169 
 1170 
 1171 Overview of changes leading to 0.9.38
 1172 Friday, January 23, 2015
 1173 =====================================
 1174 
 1175 - Fix minor out-of-bounds access in Indic shaper.
 1176 - Change New Tai Lue shaping engine from South-East Asian to default,
 1177   reflecting change in Unicode encoding model.
 1178 - Add hb-shape --font-size.  Can take up to two numbers for separate
 1179   x / y size.
 1180 - Fix CoreText and FreeType scale issues with negative scales.
 1181 - Reject blobs larger than 2GB.  This might break some icu-le-hb clients
 1182   that need security fixes.  See:
 1183   http://www.icu-project.org/trac/ticket/11450
 1184 - Avoid accessing font tables during face destruction, in casce rogue
 1185   clients released face data already.
 1186 - Fix up gobject-introspection a bit.  Python bindings kinda working.
 1187   See README.python.
 1188 - Misc fixes.
 1189 - API additions:
 1190   hb_ft_face_create_referenced()
 1191   hb_ft_font_create_referenced()
 1192 
 1193 
 1194 Overview of changes leading to 0.9.37
 1195 Wednesday, December 17, 2014
 1196 =====================================
 1197 
 1198 - Fix out-of-bounds access in Context lookup format 3.
 1199 - Indic: Allow ZWJ/ZWNJ before syllable modifiers.
 1200 
 1201 
 1202 Overview of changes leading to 0.9.36
 1203 Thursday, November 20, 2014
 1204 =====================================
 1205 
 1206 - First time that three months went by without a release since
 1207   0.9.2 was released on August 10, 2012!
 1208 - Fix performance bug in hb_ot_collect_glyphs():
 1209   https://bugzilla.mozilla.org/show_bug.cgi?id=1090869
 1210 - Add basic vertical-text support to hb-ot-font.
 1211 - Misc build fixes.
 1212 
 1213 
 1214 Overview of changes leading to 0.9.35
 1215 Saturday, August 13, 2014
 1216 =====================================
 1217 
 1218 - Fix major shape-plan caching bug when more than one shaper were
 1219   provided to hb_shape_full() (as exercised by XeTeX).
 1220   http://www.mail-archive.com/debian-bugs-dist@lists.debian.org/msg1246370.html
 1221 - Fix Arabic fallback shaping regression.  This was broken in 0.9.32.
 1222 - Major hb-coretext fixes.  That backend is complete now, including
 1223   respecing buffer direction and language, down to vertical writing.
 1224 - Build fixes for Windows CE.  Should build fine now.
 1225 - Misc fixes:
 1226   Use atexit() only if it's safe to call from shared library
 1227   https://bugs.freedesktop.org/show_bug.cgi?id=82246
 1228   Mandaic had errors in its Unicode Joining_Type
 1229   https://bugs.freedesktop.org/show_bug.cgi?id=82306
 1230 - API changes:
 1231 
 1232   * hb_buffer_clear_contents() does not reset buffer flags now.
 1233 
 1234     After 763e5466c0a03a7c27020e1e2598e488612529a7, one doesn't
 1235     need to set flags for different pieces of text.  The flags now
 1236     are something the client sets up once, depending on how it
 1237     actually uses the buffer.  As such, don't clear it in
 1238     clear_contents().
 1239 
 1240     I don't expect any changes to be needed to any existing client.
 1241 
 1242 
 1243 Overview of changes leading to 0.9.34
 1244 Saturday, August 2, 2014
 1245 =====================================
 1246 
 1247 - hb_feature_from_string() now accepts CSS font-feature-settings format.
 1248 - As a result, hb-shape / hb-view --features also accept CSS-style strings.
 1249   Eg, "'liga' off" is accepted now.
 1250 - Add old-spec Myanmar shaper:
 1251   https://bugs.freedesktop.org/show_bug.cgi?id=81775
 1252 - Don't apply 'calt' in Hangul shaper.
 1253 - Fix mark advance zeroing for Hebrew shaper:
 1254   https://bugs.freedesktop.org/show_bug.cgi?id=76767
 1255 - Implement Windows-1256 custom Arabic shaping.  Only built on Windows,
 1256   and requires help from get_glyph().  Used by Firefox.
 1257   https://bugzilla.mozilla.org/show_bug.cgi?id=1045139
 1258 - Disable 'liga' in vertical text.
 1259 - Build fixes.
 1260 - API changes:
 1261 
 1262   * Make HB_BUFFER_FLAG_BOT/EOT easier to use.
 1263 
 1264     Previously, we expected users to provide BOT/EOT flags when the
 1265     text *segment* was at paragraph boundaries.  This meant that for
 1266     clients that provide full paragraph to HarfBuzz (eg. Pango), they
 1267     had code like this:
 1268 
 1269       hb_buffer_set_flags (hb_buffer,
 1270                            (item_offset == 0 ? HB_BUFFER_FLAG_BOT : 0) |
 1271                            (item_offset + item_length == paragraph_length ?
 1272                             HB_BUFFER_FLAG_EOT : 0));
 1273 
 1274       hb_buffer_add_utf8 (hb_buffer,
 1275                           paragraph_text, paragraph_length,
 1276                           item_offset, item_length);
 1277 
 1278     After this change such clients can simply say:
 1279 
 1280       hb_buffer_set_flags (hb_buffer,
 1281                            HB_BUFFER_FLAG_BOT | HB_BUFFER_FLAG_EOT);
 1282 
 1283       hb_buffer_add_utf8 (hb_buffer,
 1284                           paragraph_text, paragraph_length,
 1285                           item_offset, item_length);
 1286 
 1287     Ie, HarfBuzz itself checks whether the segment is at the beginning/end
 1288     of the paragraph.  Clients that only pass item-at-a-time to HarfBuzz
 1289     continue not setting any flags whatsoever.
 1290 
 1291     Another way to put it is: if there's pre-context text in the buffer,
 1292     HarfBuzz ignores the BOT flag.  If there's post-context, it ignores
 1293     EOT flag.
 1294 
 1295 
 1296 Overview of changes leading to 0.9.33
 1297 Tuesday, July 22, 2014
 1298 =====================================
 1299 
 1300 - Turn off ARabic 'cswh' feature that was accidentally turned on.
 1301 - Add HB_TAG_MAX_SIGNED.
 1302 - Make hb_face_make_immutable() really make face immutable!
 1303 - Windows build fixes.
 1304 
 1305 
 1306 Overview of changes leading to 0.9.32
 1307 Thursday, July 17, 2014
 1308 =====================================
 1309 
 1310 - Apply Arabic shaping features in spec order exactly.
 1311 - Another fix for Mongolian free variation selectors.
 1312 - For non-Arabic scripts in Arabic shaper apply 'rlig' and 'calt'
 1313   together.
 1314 - Minor adjustment to U+FFFD logic.
 1315 - Fix hb-coretext build.
 1316 
 1317 
 1318 Overview of changes leading to 0.9.31
 1319 Wednesday, July 16, 2014
 1320 =====================================
 1321 
 1322 - Only accept valid UTF-8/16/32; we missed many cases before.
 1323 - Better shaping of invalid UTF-8/16/32.  Falls back to
 1324   U+FFFD REPLACEMENT CHARACTER now.
 1325 - With all changes in this release, the buffer will contain fully
 1326   valid Unicode after hb_buffer_add_utf8/16/32 no matter how
 1327   broken the input is.  This can be overridden though.  See below.
 1328 - Fix Mongolian Variation Selectors for fonts without GDEF.
 1329 - Fix minor invalid buffer access.
 1330 - Accept zh-Hant and zh-Hans language tags.  hb_ot_tag_to_language()
 1331   now uses these instead of private tags.
 1332 - Build fixes.
 1333 - New API:
 1334   * hb_buffer_add_codepoints().  This does what hb_buffer_add_utf32()
 1335     used to do, ie. no validity check on the input at all.  add_utf32
 1336     now replaces invalid Unicode codepoints with the replacement
 1337     character (see below).
 1338   * hb_buffer_set_replacement_codepoint()
 1339   * hb_buffer_get_replacement_codepoint()
 1340     Previously, in hb_buffer_add_utf8 and hb_buffer_add_utf16, when
 1341     we detected broken input, we replaced that with (hb_codepoint_t)-1.
 1342     This has changed to use U+FFFD now, but can be changed using these
 1343     new API.
 1344 
 1345 
 1346 Overview of changes leading to 0.9.30
 1347 Wednesday, July 9, 2014
 1348 =====================================
 1349 
 1350 - Update to Unicode 7.0.0:
 1351   * New scripts Manichaean and Psalter Pahlavi are shaped using
 1352     Arabic shaper.
 1353   * All the other new scripts to through the generic shaper for
 1354     now.
 1355 - Minor Indic improvements.
 1356 - Fix graphite2 backend cluster mapping [crasher!]
 1357 - API changes:
 1358   * New HB_SCRIPT_* values for Unicode 7.0 scripts.
 1359   * New function hb_ot_layout_language_get_required_feature().
 1360 - Build fixes.
 1361 
 1362 
 1363 Overview of changes leading to 0.9.29
 1364 Thursday, May 29, 2014
 1365 =====================================
 1366 
 1367 - Implement cmap in hb-ot-font.h.  No variation-selectors yet.
 1368 - Myanmar: Allow MedialYa+Asat.
 1369 - Various Indic fixes:
 1370   * Support most characters in Extended Devanagary and Vedic
 1371     Unicode blocks.
 1372   * Allow digits and a some punctuation as consonant placeholders.
 1373 - Build fixes.
 1374 
 1375 
 1376 Overview of changes leading to 0.9.28
 1377 Monday, April 28, 2014
 1378 =====================================
 1379 
 1380 - Unbreak old-spec Indic shaping. (bug 76705)
 1381 - Fix shaping of U+17DD and U+0FC6.
 1382 - Add HB_NO_MERGE_CLUSTERS build option.  NOT to be enabled by default
 1383   for shipping libraries.  It's an option for further experimentation
 1384   right now.  When we are sure how to do it properly, we will add
 1385   public run-time API for the functionality.
 1386 - Build fixes.
 1387 
 1388 
 1389 Overview of changes leading to 0.9.27
 1390 Tuesday, March 18, 2014
 1391 =====================================
 1392 
 1393 - Don't use "register" storage class specifier
 1394 - Wrap definition of free_langs() with HAVE_ATEXIT
 1395 - Add coretext_aat shaper and hb_coretext_face_create() constructor
 1396 - If HAVE_ICU_BUILTIN is defined, use hb-icu Unicode callbacks
 1397 - Add Myanmar test case from OpenType Myanmar spec
 1398 - Only do fallback Hebrew composition if no GPOS 'mark' available
 1399 - Allow bootstrapping without gtk-doc
 1400 - Use AM_MISSING_PROG for ragel and git
 1401 - Typo in ucdn's Makefile.am
 1402 - Improve MemoryBarrier() implementation
 1403 
 1404 
 1405 Overview of changes leading to 0.9.26
 1406 Thursday, January 30, 2014
 1407 =====================================
 1408 
 1409 - Misc fixes.
 1410 - Fix application of 'rtlm' feature.
 1411 - Automatically apply frac/numr/dnom around U+2044 FRACTION SLASH.
 1412 - New header: hb-ot-shape.h
 1413 - Uniscribe: fix scratch-buffer accounting.
 1414 - Reorder Tai Tham SAKOT to after tone-marks.
 1415 - Add Hangul shaper.
 1416 - New files:
 1417   hb-ot-shape-complex-hangul.cc
 1418   hb-ot-shape-complex-hebrew.cc
 1419   hb-ot-shape-complex-tibetan.cc
 1420 - Disable 'cswh' feature in Arabic shaper.
 1421 - Coretext: better handle surrogate pairs.
 1422 - Add HB_TAG_MAX and _HB_SCRIPT_MAX_VALUE.
 1423 
 1424 
 1425 Overview of changes leading to 0.9.25
 1426 Wednesday, December 4, 2013
 1427 =====================================
 1428 
 1429 - Myanmar shaper improvements.
 1430 - Avoid font fallback in CoreText backend.
 1431 - Additional OpenType language tag mappiongs.
 1432 - More aggressive shape-plan caching.
 1433 - Build with / require automake 1.13.
 1434 - Build with libtool 2.4.2.418 alpha to support ppc64le.
 1435 
 1436 
 1437 Overview of changes leading to 0.9.24
 1438 Tuesday, November 13, 2013
 1439 =====================================
 1440 
 1441 - Misc compiler warning fixes with clang.
 1442 - No functional changes.
 1443 
 1444 
 1445 Overview of changes leading to 0.9.23
 1446 Monday, October 28, 2013
 1447 =====================================
 1448 
 1449 - "Udupi HarfBuzz Hackfest", Paris, October 14..18 2013.
 1450 - Fix (Chain)Context recursion with non-monotone lookup positions.
 1451 - Misc Indic bug fixes.
 1452 - New Javanese / Buginese shaping, similar to Windows 8.1.
 1453 
 1454 
 1455 Overview of changes leading to 0.9.22
 1456 Thursday, October 3, 2013
 1457 =====================================
 1458 
 1459 - Fix use-after-end-of-scope in hb_language_from_string().
 1460 - Fix hiding of default_ignorables if font doesn't have space glyph.
 1461 - Protect against out-of-range lookup indices.
 1462 
 1463 - API Changes:
 1464 
 1465   * Added hb_ot_layout_table_get_lookup_count()
 1466 
 1467 
 1468 Overview of changes leading to 0.9.21
 1469 Monday, September 16, 2013
 1470 =====================================
 1471 
 1472 - Rename gobject-introspection library name from harfbuzz to HarfBuzz.
 1473 - Remove (long disabled) hb-old and hb-icu-le test shapers.
 1474 - Misc gtk-doc and gobject-introspection annotations.
 1475 - Misc fixes.
 1476 - API changes:
 1477 
 1478   * Add HB_SET_VALUE_INVALID
 1479 
 1480 Overview of changes leading to 0.9.20
 1481 Thursday, August 29, 2013
 1482 =====================================
 1483 
 1484 General:
 1485 - Misc substitute_closure() fixes.
 1486 - Build fixes.
 1487 
 1488 Documentation:
 1489 - gtk-doc boilerplate integrated.  Docs are built now, but
 1490   contain no contents.  By next release hopefully we have
 1491   some content in.  Enable using --enable-gtk-doc.
 1492 
 1493 GObject and Introspection:
 1494 - Added harfbuzz-gobject library (hb-gobject.h) that has type
 1495   bindings for all HarfBuzz objects and enums.  Enable using
 1496   --with-gobject.
 1497 - Added gobject-introspection boilerplate.  Nothing useful
 1498   right now.  Work in progress.  Gets enabled automatically if
 1499   --with-gobject is used.  Override with --disable-introspection.
 1500 
 1501 OpenType shaper:
 1502 - Apply 'mark' in Myanmar shaper.
 1503 - Don't apply 'dlig' by default.
 1504 
 1505 Uniscribe shaper:
 1506 - Support user features.
 1507 - Fix loading of fonts that are also installed on the system.
 1508 - Fix shaping of Arabic Presentation Forms.
 1509 - Fix build with wide chars.
 1510 
 1511 CoreText shaper:
 1512 - Support user features.
 1513 
 1514 Source changes:
 1515 - hb_face_t code moved to hb-face.h / hb-face.cc.
 1516 - Added hb-deprecated.h.
 1517 
 1518 API changes:
 1519 - Added HB_DISABLE_DEPRECATED.
 1520 - Deprecated HB_SCRIPT_CANADIAN_ABORIGINAL; replaced by
 1521   HB_SCRIPT_CANADIAN_SYLLABICS.
 1522 - Deprecated HB_BUFFER_FLAGS_DEFAULT; replaced by
 1523   HB_BUFFER_FLAG_DEFAULT.
 1524 - Deprecated HB_BUFFER_SERIALIZE_FLAGS_DEFAULT; replaced by
 1525   HB_BUFFER_SERIALIZE_FLAG_DEFAULT.
 1526 
 1527 
 1528 Overview of changes leading to 0.9.19
 1529 Tuesday, July 16, 2013
 1530 =====================================
 1531 
 1532 - Build fixes.
 1533 - Better handling of multiple variation selectors in a row.
 1534 - Pass on variation selector to GSUB if not consumed by cmap.
 1535 - Fix undefined memory access.
 1536 - Add Javanese config to Indic shaper.
 1537 - Misc bug fixes.
 1538 
 1539 Overview of changes leading to 0.9.18
 1540 Tuesday, May 28, 2013
 1541 =====================================
 1542 
 1543 New build system:
 1544 
 1545 - All unneeded code is all disabled by default,
 1546 
 1547 - Uniscribe and CoreText shapers can be enabled with their --with options,
 1548 
 1549 - icu_le and old shapers cannot be enabled for now,
 1550 
 1551 - glib, freetype, and cairo will be detected automatically.
 1552   They can be force on/off'ed with their --with options,
 1553 
 1554 - icu and graphite2 are default off, can be enabled with their --with
 1555   options,
 1556 
 1557 Moreover, ICU support is now build into a separate library:
 1558 libharfbuzz-icu.so, and a new harfbuzz-icu.pc is shipped for it.
 1559 Distros can enable ICU now without every application on earth
 1560 getting linked to via libharfbuzz.so.
 1561 
 1562 For distros I recommend that they make sure they are building --with-glib
 1563 --with-freetype --with-cairo, --with-icu, and optionally --with-graphite2;
 1564 And package harfbuzz and harfbuzz-icu separately.
 1565 
 1566 
 1567 Overview of changes leading to 0.9.17
 1568 Monday, May 20, 2013
 1569 =====================================
 1570 
 1571 - Build fixes.
 1572 - Fix bug in hb_set_get_min().
 1573 - Fix regression with Arabic mark positioning / width-zeroing.
 1574 
 1575 Overview of changes leading to 0.9.16
 1576 Friday, April 19, 2013
 1577 =====================================
 1578 
 1579 - Major speedup in OpenType lookup processing.  With the Amiri
 1580   Arabic font, this release is over 3x faster than previous
 1581   release.  All scripts / languages should see this speedup.
 1582 
 1583 - New --num-iterations option for hb-shape / hb-view; useful for
 1584   profiling.
 1585 
 1586 Overview of changes leading to 0.9.15
 1587 Friday, April 05, 2013
 1588 =====================================
 1589 
 1590 - Build fixes.
 1591 - Fix crasher in graphite2 shaper.
 1592 - Fix Arabic mark width zeroing regression.
 1593 - Don't compose Hangul jamo into Unicode syllables.
 1594 
 1595 
 1596 Overview of changes leading to 0.9.14
 1597 Thursday, March 21, 2013
 1598 =====================================
 1599 
 1600 - Build fixes.
 1601 - Fix time-consuming sanitize with malicious fonts.
 1602 - Implement hb_buffer_deserialize_glyphs() for both json and text.
 1603 - Do not ignore Hangul filler characters.
 1604 - Indic fixes:
 1605   * Fix Malayalam pre-base reordering interaction with post-forms.
 1606   * Further adjust ZWJ handling.  Should fix known regressions from
 1607     0.9.13.
 1608 
 1609 
 1610 Overview of changes leading to 0.9.13
 1611 Thursday, February 25, 2013
 1612 =====================================
 1613 
 1614 - Build fixes.
 1615 - Ngapi HarfBuzz Hackfest in London (February 2013):
 1616   * Fixed all known Indic bugs,
 1617   * New Win8-style Myanmar shaper,
 1618   * New South-East Asian shaper for Tai Tham, Cham, and New Tai Lue,
 1619   * Smartly ignore Default_Ignorable characters (joiners, etc) wheb
 1620     matching GSUB/GPOS lookups,
 1621   * Fix 'Phags-Pa U+A872 shaping,
 1622   * Fix partial disabling of default-on features,
 1623   * Allow disabling of TrueType kerning.
 1624 - Fix possible crasher with broken fonts with overlapping tables.
 1625 - Removed generated files from git again.  So, one needs ragel to
 1626   bootstrap from the git tree.
 1627 
 1628 API changes:
 1629 - hb_shape() and related APIs now abort if buffer direction is
 1630   HB_DIRECTION_INVALID.  Previously, hb_shape() was calling
 1631   hb_buffer_guess_segment_properties() on the buffer before
 1632   shaping.  The heuristics in that function are fragile.  If the
 1633   user really wants the old behvaior, they can call that function
 1634   right before calling hb_shape() to get the old behavior.
 1635 - hb_blob_create_sub_blob() always creates sub-blob with
 1636   HB_MEMORY_MODE_READONLY.  See comments for the reason.
 1637 
 1638 
 1639 Overview of changes leading to 0.9.12
 1640 Thursday, January 18, 2013
 1641 =====================================
 1642 
 1643 - Build fixes for Sun compiler.
 1644 - Minor bug fix.
 1645 
 1646 Overview of changes leading to 0.9.11
 1647 Thursday, January 10, 2013
 1648 =====================================
 1649 
 1650 - Build fixes.
 1651 - Fix GPOS mark attachment with null Anchor offsets.
 1652 - [Indic] Fix old-spec reordering of viramas if sequence ends in one.
 1653 - Fix multi-threaded shaper data creation crash.
 1654 - Add atomic ops for Solaris.
 1655 
 1656 API changes:
 1657 - Rename hb_buffer_clear() to hb_buffer_clear_contents().
 1658 
 1659 
 1660 Overview of changes leading to 0.9.10
 1661 Thursday, January 3, 2013
 1662 =====================================
 1663 
 1664 - [Indic] Fixed rendering of Malayalam dot-reph
 1665 - Updated OT language tags.
 1666 - Updated graphite2 backend.
 1667 - Improved hb_ot_layout_get_size_params() logic.
 1668 - Improve hb-shape/hb-view help output.
 1669 - Fixed hb-set.h implementation to not crash.
 1670 - Fixed various issues with hb_ot_layout_collect_lookups().
 1671 - Various build fixes.
 1672 
 1673 New API:
 1674 
 1675 hb_graphite2_face_get_gr_face()
 1676 hb_graphite2_font_get_gr_font()
 1677 hb_coretext_face_get_cg_font()
 1678 
 1679 Modified API:
 1680 
 1681 hb_ot_layout_get_size_params()
 1682 
 1683 
 1684 Overview of changes leading to 0.9.9
 1685 Wednesday, December 5, 2012
 1686 ====================================
 1687 
 1688 - Fix build on Windows.
 1689 - Minor improvements.
 1690 
 1691 
 1692 Overview of changes leading to 0.9.8
 1693 Tuesday, December 4, 2012
 1694 ====================================
 1695 
 1696 
 1697 - Actually implement hb_shape_plan_get_shaper ().
 1698 - Make UCDB data tables const.
 1699 - Lots of internal refactoring in OTLayout tables.
 1700 - Flesh out hb_ot_layout_lookup_collect_glyphs().
 1701 
 1702 New API:
 1703 
 1704 hb_ot_layout_collect_lookups()
 1705 hb_ot_layout_get_size_params()
 1706 
 1707 
 1708 Overview of changes leading to 0.9.7
 1709 Sunday, November 21, 2012
 1710 ====================================
 1711 
 1712 
 1713 HarfBuzz "All-You-Can-Eat-Sushi" (aka Vancouver) Hackfest and follow-on fixes.
 1714 
 1715 - Fix Arabic contextual joining using pre-context text.
 1716 - Fix Sinhala "split matra" mess.
 1717 - Fix Khmer shaping with broken fonts.
 1718 - Implement Thai "PUA" shaping for old fonts.
 1719 - Do NOT route Kharoshthi script through the Indic shaper.
 1720 - Disable fallback positioning for Indic and Thai shapers.
 1721 - Misc fixes.
 1722 
 1723 
 1724 hb-shape / hb-view changes:
 1725 
 1726 - Add --text-before and --text-after
 1727 - Add --bot / --eot / --preserve-default-ignorables
 1728 - hb-shape --output-format=json
 1729 
 1730 
 1731 New API:
 1732 
 1733 hb_buffer_clear()
 1734 
 1735 hb_buffer_flags_t
 1736 
 1737 HB_BUFFER_FLAGS_DEFAULT
 1738 HB_BUFFER_FLAG_BOT
 1739 HB_BUFFER_FLAG_EOT
 1740 HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES
 1741 
 1742 hb_buffer_set_flags()
 1743 hb_buffer_get_flags()
 1744 
 1745 HB_BUFFER_SERIALIZE_FLAGS
 1746 hb_buffer_serialize_glyphs()
 1747 hb_buffer_deserialize_glyphs()
 1748 hb_buffer_serialize_list_formats()
 1749 
 1750 hb_set_add_range()
 1751 hb_set_del_range()
 1752 hb_set_get_population()
 1753 hb_set_next_range()
 1754 
 1755 hb_face_[sg]et_glyph_count()
 1756 
 1757 hb_segment_properties_t
 1758 HB_SEGMENT_PROPERTIES_DEFAULT
 1759 hb_segment_properties_equal()
 1760 hb_segment_properties_hash()
 1761 
 1762 hb_buffer_set_segment_properties()
 1763 hb_buffer_get_segment_properties()
 1764 
 1765 hb_ot_layout_glyph_class_t
 1766 hb_ot_layout_get_glyph_class()
 1767 hb_ot_layout_get_glyphs_in_class()
 1768 
 1769 hb_shape_plan_t
 1770 hb_shape_plan_create()
 1771 hb_shape_plan_create_cached()
 1772 hb_shape_plan_get_empty()
 1773 hb_shape_plan_reference()
 1774 hb_shape_plan_destroy()
 1775 hb_shape_plan_set_user_data()
 1776 hb_shape_plan_get_user_data()
 1777 hb_shape_plan_execute()
 1778 hb_shape_plan_get_shaper()
 1779 
 1780 hb_ot_shape_plan_collect_lookups()
 1781 
 1782 
 1783 API changes:
 1784 
 1785 - Remove "mask" parameter from hb_buffer_add().
 1786 - Rename hb_ot_layout_would_substitute_lookup() and hb_ot_layout_substitute_closure_lookup().
 1787 - hb-set.h API const correction.
 1788 - Renamed hb_set_min/max() to hb_set_get_min/max().
 1789 - Rename hb_ot_layout_feature_get_lookup_indexes() to hb_ot_layout_feature_get_lookups().
 1790 - Rename hb_buffer_guess_properties() to hb_buffer_guess_segment_properties().
 1791 
 1792 
 1793 
 1794 Overview of changes leading to 0.9.6
 1795 Sunday, November 13, 2012
 1796 ====================================
 1797 
 1798 - Don't clear pre-context text if no new context is provided.
 1799 - Fix ReverseChainingSubstLookup, which was totally borked.
 1800 - Adjust output format of hb-shape a bit.
 1801 - Include config.h.in in-tree.  Makes it easier for alternate build systems.
 1802 - Fix hb_buffer_set_length(buffer, 0) invalid memory allocation.
 1803 - Use ICU LayoutEngine's C API instead of C++.  Avoids much headache.
 1804 - Drop glyphs for all of Unicode Default_Ignorable characters.
 1805 - Misc build fixes.
 1806 
 1807 Arabic shaper:
 1808 - Enable 'dlig' and 'mset' features in Arabic shaper.
 1809 - Implement 'Phags-pa shaping, improve Mongolian.
 1810 
 1811 Indic shaper:
 1812 - Decompose Sinhala split matras the way old HarfBuzz / Pango did.
 1813 - Initial support for Consonant Medials.
 1814 - Start adding new-style Myanmar shaping.
 1815 - Make reph and 'pref' logic introspect the font.
 1816 - Route Meetei-Mayek through the Indic shaper.
 1817 - Don't apply 'liga' in Indic shaper.
 1818 - Improve Malayalam pre-base reordering Ra interaction with Chillus.
 1819 
 1820 
 1821 
 1822 Overview of changes leading to 0.9.5
 1823 Sunday, October 14, 2012
 1824 ====================================
 1825 
 1826 - Synthetic-GSUB Arabic fallback shaping.
 1827 
 1828 - Misc Indic improvements.
 1829 
 1830 - Add build system support for pthread.
 1831 
 1832 - Imported UCDN for in-tree Unicode callbacks implementation.
 1833 
 1834 - Context-aware Arabic joining.
 1835 
 1836 - Misc other fixes.
 1837 
 1838 - New API:
 1839 
 1840   hb_feature_to/from-string()
 1841   hb_buffer_[sg]et_content_type()
 1842 
 1843 
 1844 
 1845 Overview of changes leading to 0.9.4
 1846 Tuesday, Sep 03, 2012
 1847 ====================================
 1848 
 1849 - Indic improvements with old-spec Malayalam.
 1850 
 1851 - Better fallback glyph positioning, specially with Thai / Lao marks.
 1852 
 1853 - Implement dotted-circle insertion.
 1854 
 1855 - Better Arabic fallback shaping / ligation.
 1856 
 1857 - Added ICU LayoutEngine backend for testing.  Call it by the 'icu_le' name.
 1858 
 1859 - Misc fixes.
 1860 
 1861 
 1862 
 1863 Overview of changes leading to 0.9.3
 1864 Friday, Aug 18, 2012
 1865 ====================================
 1866 
 1867 - Fixed fallback mark positioning for left-to-right text.
 1868 
 1869 - Improve mark positioning for the remaining combining classes.
 1870 
 1871 - Unbreak Thai and fallback Arabic shaping.
 1872 
 1873 - Port Arabic shaper to shape-plan caching.
 1874 
 1875 - Use new ICU normalizer functions.
 1876 
 1877 
 1878 
 1879 Overview of changes leading to 0.9.2
 1880 Friday, Aug 10, 2012
 1881 ====================================
 1882 
 1883 - Over a thousand commits!  This is the first major release of HarfBuzz.
 1884 
 1885 - HarfBuzz is feature-complete now!  It should be in par, or better, than
 1886   both Pango's shapers and old HarfBuzz / Qt shapers.
 1887 
 1888 - New Indic shaper, supporting main Indic scripts, Sinhala, and Khmer.
 1889 
 1890 - Improved Arabic shaper, with fallback Arabic shaping, supporting Arabic,
 1891   Sinhala, N'ko, Mongolian, and Mandaic.
 1892 
 1893 - New Thai / Lao shaper.
 1894 
 1895 - Tibetan / Hangul support in the generic shaper.
 1896 
 1897 - Synthetic GDEF support for fonts without a GDEF table.
 1898 
 1899 - Fallback mark positioning for fonts without a GPOS table.
 1900 
 1901 - Unicode normalization shaping heuristic during glyph mapping.
 1902 
 1903 - New experimental Graphite2 backend.
 1904 
 1905 - New Uniscribe backend (primarily for testing).
 1906 
 1907 - New CoreText backend (primarily for testing).
 1908 
 1909 - Major optimization and speedup.
 1910 
 1911 - Test suites and testing infrastructure (work in progress).
 1912 
 1913 - Greatly improved hb-view cmdline tool.
 1914 
 1915 - hb-shape cmdline tool.
 1916 
 1917 - Unicode 6.1 support.
 1918 
 1919 Summary of API changes:
 1920 
 1921 o Changed API:
 1922 
 1923   - Users are expected to only include main header files now (ie. hb.h,
 1924     hb-glib.h, hb-ft.h, ...)
 1925 
 1926   - All struct tag names had their initial underscore removed.
 1927     Ie. "struct _hb_buffer_t" is "struct hb_buffer_t" now.
 1928 
 1929   - All set_user_data() functions now take a "replace" boolean parameter.
 1930 
 1931   - hb_buffer_create() takes zero arguments now.
 1932     Use hb_buffer_pre_allocate() to pre-allocate.
 1933 
 1934   - hb_buffer_add_utf*() now accept -1 for length parameteres,
 1935     meaning "nul-terminated".
 1936 
 1937   - hb_direction_t enum values changed.
 1938 
 1939   - All *_from_string() APIs now take a length parameter to allow for
 1940     non-nul-terminated strings. A -1 length means "nul-terminated".
 1941 
 1942   - Typedef for hb_language_t changed.
 1943 
 1944   - hb_get_table_func_t renamed to hb_reference_table_func_t.
 1945 
 1946   - hb_ot_layout_table_choose_script()
 1947 
 1948   - Various renames in hb-unicode.h.
 1949 
 1950 o New API:
 1951 
 1952   - hb_buffer_guess_properties()
 1953     Automatically called by hb_shape().
 1954 
 1955   - hb_buffer_normalize_glyphs()
 1956 
 1957   - hb_tag_from_string()
 1958 
 1959   - hb-coretext.h
 1960 
 1961   - hb-uniscribe.h
 1962 
 1963   - hb_face_reference_blob()
 1964   - hb_face_[sg]et_index()
 1965   - hb_face_set_upem()
 1966 
 1967   - hb_font_get_glyph_name_func_t
 1968     hb_font_get_glyph_from_name_func_t
 1969     hb_font_funcs_set_glyph_name_func()
 1970     hb_font_funcs_set_glyph_from_name_func()
 1971     hb_font_get_glyph_name()
 1972     hb_font_get_glyph_from_name()
 1973     hb_font_glyph_to_string()
 1974     hb_font_glyph_from_string()
 1975 
 1976   - hb_font_set_funcs_data()
 1977 
 1978   - hb_ft_font_set_funcs()
 1979   - hb_ft_font_get_face()
 1980 
 1981   - hb-gobject.h (work in progress)
 1982 
 1983   - hb_ot_shape_glyphs_closure()
 1984     hb_ot_layout_substitute_closure_lookup()
 1985 
 1986   - hb-set.h
 1987 
 1988   - hb_shape_full()
 1989 
 1990   - hb_unicode_combining_class_t
 1991 
 1992   - hb_unicode_compose_func_t
 1993     hb_unicode_decompose_func_t
 1994     hb_unicode_decompose_compatibility_func_t
 1995     hb_unicode_funcs_set_compose_func()
 1996     hb_unicode_funcs_set_decompose_func()
 1997     hb_unicode_funcs_set_decompose_compatibility_func()
 1998     hb_unicode_compose()
 1999     hb_unicode_decompose()
 2000     hb_unicode_decompose_compatibility()
 2001 
 2002 o Removed API:
 2003 
 2004   - hb_ft_get_font_funcs()
 2005 
 2006   - hb_ot_layout_substitute_start()
 2007     hb_ot_layout_substitute_lookup()
 2008     hb_ot_layout_substitute_finish()
 2009     hb_ot_layout_position_start()
 2010     hb_ot_layout_position_lookup()
 2011     hb_ot_layout_position_finish()
 2012 
 2013 
 2014 
 2015 Overview of changes leading to 0.6.0
 2016 Friday, May 27, 2011
 2017 ====================================
 2018 
 2019 - Vertical text support in GPOS
 2020 - Almost all API entries have unit tests now, under test/
 2021 - All thread-safety issues are fixed
 2022 
 2023 Summary of API changes follows.
 2024 
 2025 
 2026 * Simple Types API:
 2027 
 2028   o New API:
 2029     HB_LANGUAGE_INVALID
 2030     hb_language_get_default()
 2031     hb_direction_to_string()
 2032     hb_direction_from_string()
 2033     hb_script_get_horizontal_direction()
 2034     HB_UNTAG()
 2035 
 2036   o Renamed API:
 2037     hb_category_t renamed to hb_unicode_general_category_t
 2038 
 2039   o Changed API:
 2040     hb_language_t is a typed pointers now
 2041 
 2042   o Removed API:
 2043     HB_TAG_STR()
 2044 
 2045 
 2046 * Use ISO 15924 tags for hb_script_t:
 2047 
 2048   o New API:
 2049     hb_script_from_iso15924_tag()
 2050     hb_script_to_iso15924_tag()
 2051     hb_script_from_string()
 2052 
 2053   o Changed API:
 2054     HB_SCRIPT_* enum members changed value.
 2055 
 2056 
 2057 * Buffer API streamlined:
 2058 
 2059   o New API:
 2060     hb_buffer_reset()
 2061     hb_buffer_set_length()
 2062     hb_buffer_allocation_successful()
 2063 
 2064   o Renamed API:
 2065     hb_buffer_ensure() renamed to hb_buffer_pre_allocate()
 2066     hb_buffer_add_glyph() renamed to hb_buffer_add()
 2067 
 2068   o Removed API:
 2069     hb_buffer_clear()
 2070     hb_buffer_clear_positions()
 2071 
 2072   o Changed API:
 2073     hb_buffer_get_glyph_infos() takes an out length parameter now
 2074     hb_buffer_get_glyph_positions() takes an out length parameter now
 2075 
 2076 
 2077 * Blob API streamlined:
 2078 
 2079   o New API:
 2080     hb_blob_get_data()
 2081     hb_blob_get_data_writable()
 2082 
 2083   o Renamed API:
 2084     hb_blob_create_empty() renamed to hb_blob_get_empty()
 2085 
 2086   o Removed API:
 2087     hb_blob_lock()
 2088     hb_blob_unlock()
 2089     hb_blob_is_writable()
 2090     hb_blob_try_writable()
 2091 
 2092   o Changed API:
 2093     hb_blob_create() takes user_data before destroy now
 2094 
 2095 
 2096 * Unicode functions API:
 2097 
 2098   o Unicode function vectors can subclass other unicode function vectors now.
 2099     Unimplemented callbacks in the subclass automatically chainup to the parent.
 2100 
 2101   o All hb_unicode_funcs_t callbacks take a user_data now.  Their setters
 2102     take a user_data and its respective destroy callback.
 2103 
 2104   o New API:
 2105     hb_unicode_funcs_get_empty()
 2106     hb_unicode_funcs_get_default()
 2107     hb_unicode_funcs_get_parent()
 2108 
 2109   o Changed API:
 2110     hb_unicode_funcs_create() now takes a parent_funcs.
 2111 
 2112   o Removed func getter functions:
 2113     hb_unicode_funcs_get_mirroring_func()
 2114     hb_unicode_funcs_get_general_category_func()
 2115     hb_unicode_funcs_get_script_func()
 2116     hb_unicode_funcs_get_combining_class_func()
 2117     hb_unicode_funcs_get_eastasian_width_func()
 2118 
 2119 
 2120 * Face API:
 2121 
 2122   o Renamed API:
 2123     hb_face_get_table() renamed to hb_face_reference_table()
 2124     hb_face_create_for_data() renamed to hb_face_create()
 2125 
 2126   o Changed API:
 2127     hb_face_create_for_tables() takes user_data before destroy now
 2128     hb_face_reference_table() returns empty blob instead of NULL
 2129     hb_get_table_func_t accepts the face as first parameter now
 2130 
 2131 * Font API:
 2132 
 2133   o Fonts can subclass other fonts now.  Unimplemented callbacks in the
 2134     subclass automatically chainup to the parent.  When chaining up,
 2135     scale is adjusted if the parent font has a different scale.
 2136 
 2137   o All hb_font_funcs_t callbacks take a user_data now.  Their setters
 2138     take a user_data and its respective destroy callback.
 2139 
 2140   o New API:
 2141     hb_font_get_parent()
 2142     hb_font_funcs_get_empty()
 2143     hb_font_create_sub_font()
 2144 
 2145   o Removed API:
 2146     hb_font_funcs_copy()
 2147     hb_font_unset_funcs()
 2148 
 2149   o Removed func getter functions:
 2150     hb_font_funcs_get_glyph_func()
 2151     hb_font_funcs_get_glyph_advance_func()
 2152     hb_font_funcs_get_glyph_extents_func()
 2153     hb_font_funcs_get_contour_point_func()
 2154     hb_font_funcs_get_kerning_func()
 2155 
 2156   o Changed API:
 2157     hb_font_create() takes a face and references it now
 2158     hb_font_set_funcs() takes user_data before destroy now
 2159     hb_font_set_scale() accepts signed integers now
 2160     hb_font_get_contour_point_func_t now takes glyph first, then point_index
 2161     hb_font_get_glyph_func_t returns a success boolean now
 2162 
 2163 
 2164 * Changed object model:
 2165 
 2166   o All object types have a _get_empty() now:
 2167     hb_blob_get_empty()
 2168     hb_buffer_get_empty()
 2169     hb_face_get_empty()
 2170     hb_font_get_empty()
 2171     hb_font_funcs_get_empty()
 2172     hb_unicode_funcs_get_empty()
 2173 
 2174   o Added _set_user_data() and _get_user_data() for all object types:
 2175     hb_blob_get_user_data()
 2176     hb_blob_set_user_data()
 2177     hb_buffer_get_user_data()
 2178     hb_buffer_set_user_data()
 2179     hb_face_get_user_data()
 2180     hb_face_set_user_data()
 2181     hb_font_funcs_get_user_data()
 2182     hb_font_funcs_set_user_data()
 2183     hb_font_get_user_data()
 2184     hb_font_set_user_data()
 2185     hb_unicode_funcs_get_user_data()
 2186     hb_unicode_funcs_set_user_data()
 2187 
 2188   o Removed the _get_reference_count() from all object types:
 2189     hb_blob_get_reference_count()
 2190     hb_buffer_get_reference_count()
 2191     hb_face_get_reference_count()
 2192     hb_font_funcs_get_reference_count()
 2193     hb_font_get_reference_count()
 2194     hb_unicode_funcs_get_reference_count()
 2195 
 2196   o Added _make_immutable() and _is_immutable() for all object types except for buffer:
 2197     hb_blob_make_immutable()
 2198     hb_blob_is_immutable()
 2199     hb_face_make_immutable()
 2200     hb_face_is_immutable()
 2201 
 2202 
 2203 * Changed API for vertical text support
 2204 
 2205   o The following callbacks where removed:
 2206     hb_font_get_glyph_advance_func_t
 2207     hb_font_get_kerning_func_t
 2208 
 2209   o The following new callbacks added instead:
 2210     hb_font_get_glyph_h_advance_func_t
 2211     hb_font_get_glyph_v_advance_func_t
 2212     hb_font_get_glyph_h_origin_func_t
 2213     hb_font_get_glyph_v_origin_func_t
 2214     hb_font_get_glyph_h_kerning_func_t
 2215     hb_font_get_glyph_v_kerning_func_t
 2216 
 2217   o The following API removed as such:
 2218     hb_font_funcs_set_glyph_advance_func()
 2219     hb_font_funcs_set_kerning_func()
 2220     hb_font_get_glyph_advance()
 2221     hb_font_get_kerning()
 2222 
 2223   o New API added instead:
 2224     hb_font_funcs_set_glyph_h_advance_func()
 2225     hb_font_funcs_set_glyph_v_advance_func()
 2226     hb_font_funcs_set_glyph_h_origin_func()
 2227     hb_font_funcs_set_glyph_v_origin_func()
 2228     hb_font_funcs_set_glyph_h_kerning_func()
 2229     hb_font_funcs_set_glyph_v_kerning_func()
 2230     hb_font_get_glyph_h_advance()
 2231     hb_font_get_glyph_v_advance()
 2232     hb_font_get_glyph_h_origin()
 2233     hb_font_get_glyph_v_origin()
 2234     hb_font_get_glyph_h_kerning()
 2235     hb_font_get_glyph_v_kerning()
 2236 
 2237   o The following higher-leve API added for convenience:
 2238     hb_font_get_glyph_advance_for_direction()
 2239     hb_font_get_glyph_origin_for_direction()
 2240     hb_font_add_glyph_origin_for_direction()
 2241     hb_font_subtract_glyph_origin_for_direction()
 2242     hb_font_get_glyph_kerning_for_direction()
 2243     hb_font_get_glyph_extents_for_origin()
 2244     hb_font_get_glyph_contour_point_for_origin()
 2245 
 2246 
 2247 * OpenType Layout API:
 2248 
 2249   o New API:
 2250     hb_ot_layout_position_start()
 2251     hb_ot_layout_substitute_start()
 2252     hb_ot_layout_substitute_finish()
 2253 
 2254 
 2255 * Glue code:
 2256 
 2257   o New API:
 2258     hb_glib_script_to_script()
 2259     hb_glib_script_from_script()
 2260     hb_icu_script_to_script()
 2261     hb_icu_script_from_script()
 2262 
 2263 
 2264 * Version API added:
 2265 
 2266   o New API:
 2267     HB_VERSION_MAJOR
 2268     HB_VERSION_MINOR
 2269     HB_VERSION_MICRO
 2270     HB_VERSION_STRING
 2271     HB_VERSION_CHECK()
 2272     hb_version()
 2273     hb_version_string()
 2274     hb_version_check()
 2275 
 2276