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Diffstat (limited to 'gfx/harfbuzz/src/hb-ot-layout.cc')
| -rw-r--r-- | gfx/harfbuzz/src/hb-ot-layout.cc | 2701 |
1 files changed, 2701 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/hb-ot-layout.cc b/gfx/harfbuzz/src/hb-ot-layout.cc new file mode 100644 index 0000000000..2eb8535db5 --- /dev/null +++ b/gfx/harfbuzz/src/hb-ot-layout.cc @@ -0,0 +1,2701 @@ +/* + * Copyright © 1998-2004 David Turner and Werner Lemberg + * Copyright © 2006 Behdad Esfahbod + * Copyright © 2007,2008,2009 Red Hat, Inc. + * Copyright © 2012,2013 Google, Inc. + * + * This is part of HarfBuzz, a text shaping library. + * + * Permission is hereby granted, without written agreement and without + * license or royalty fees, to use, copy, modify, and distribute this + * software and its documentation for any purpose, provided that the + * above copyright notice and the following two paragraphs appear in + * all copies of this software. + * + * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR + * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES + * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN + * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH + * DAMAGE. + * + * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, + * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND + * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS + * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO + * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. + * + * Red Hat Author(s): Behdad Esfahbod + * Google Author(s): Behdad Esfahbod + */ + +#include "hb.hh" + +#ifndef HB_NO_OT_LAYOUT + +#ifdef HB_NO_OT_TAG +#error "Cannot compile hb-ot-layout.cc with HB_NO_OT_TAG." +#endif + +#include "hb-open-type.hh" +#include "hb-ot-layout.hh" +#include "hb-ot-face.hh" +#include "hb-ot-map.hh" +#include "hb-map.hh" + +#include "hb-ot-kern-table.hh" +#include "hb-ot-layout-gdef-table.hh" +#include "hb-ot-layout-gsub-table.hh" +#include "hb-ot-layout-gpos-table.hh" +#include "hb-ot-layout-base-table.hh" +#include "hb-ot-layout-jstf-table.hh" // Just so we compile it; unused otherwise. +#include "hb-ot-name-table.hh" +#include "hb-ot-os2-table.hh" + +#include "hb-aat-layout-morx-table.hh" +#include "hb-aat-layout-opbd-table.hh" // Just so we compile it; unused otherwise. + +using OT::Layout::GSUB; +using OT::Layout::GPOS; + +/** + * SECTION:hb-ot-layout + * @title: hb-ot-layout + * @short_description: OpenType Layout + * @include: hb-ot.h + * + * Functions for querying OpenType Layout features in the font face. + * See the [OpenType specification](http://www.microsoft.com/typography/otspec/) + * for details. + **/ + + +/* + * kern + */ + +#ifndef HB_NO_OT_KERN +/** + * hb_ot_layout_has_kerning: + * @face: The #hb_face_t to work on + * + * Tests whether a face includes any kerning data in the 'kern' table. + * Does NOT test for kerning lookups in the GPOS table. + * + * Return value: `true` if data found, `false` otherwise + * + **/ +bool +hb_ot_layout_has_kerning (hb_face_t *face) +{ + return face->table.kern->has_data (); +} + +/** + * hb_ot_layout_has_machine_kerning: + * @face: The #hb_face_t to work on + * + * Tests whether a face includes any state-machine kerning in the 'kern' table. + * Does NOT examine the GPOS table. + * + * Return value: `true` if data found, `false` otherwise + * + **/ +bool +hb_ot_layout_has_machine_kerning (hb_face_t *face) +{ + return face->table.kern->has_state_machine (); +} + +/** + * hb_ot_layout_has_cross_kerning: + * @face: The #hb_face_t to work on + * + * Tests whether a face has any cross-stream kerning (i.e., kerns + * that make adjustments perpendicular to the direction of the text + * flow: Y adjustments in horizontal text or X adjustments in + * vertical text) in the 'kern' table. + * + * Does NOT examine the GPOS table. + * + * Return value: `true` is data found, `false` otherwise + * + **/ +bool +hb_ot_layout_has_cross_kerning (hb_face_t *face) +{ + return face->table.kern->has_cross_stream (); +} + +void +hb_ot_layout_kern (const hb_ot_shape_plan_t *plan, + hb_font_t *font, + hb_buffer_t *buffer) +{ + hb_blob_t *blob = font->face->table.kern.get_blob (); + const AAT::kern& kern = *blob->as<AAT::kern> (); + + AAT::hb_aat_apply_context_t c (plan, font, buffer, blob); + + if (!buffer->message (font, "start table kern")) return; + kern.apply (&c); + (void) buffer->message (font, "end table kern"); +} +#endif + + +/* + * GDEF + */ + +bool +OT::GDEF::is_blocklisted (hb_blob_t *blob, + hb_face_t *face) const +{ +#ifdef HB_NO_OT_LAYOUT_BLOCKLIST + return false; +#endif + /* The ugly business of blocklisting individual fonts' tables happen here! + * See this thread for why we finally had to bend in and do this: + * https://lists.freedesktop.org/archives/harfbuzz/2016-February/005489.html + * + * In certain versions of Times New Roman Italic and Bold Italic, + * ASCII double quotation mark U+0022 has wrong glyph class 3 (mark) + * in GDEF. Many versions of Tahoma have bad GDEF tables that + * incorrectly classify some spacing marks such as certain IPA + * symbols as glyph class 3. So do older versions of Microsoft + * Himalaya, and the version of Cantarell shipped by Ubuntu 16.04. + * + * Nuke the GDEF tables of to avoid unwanted width-zeroing. + * + * See https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 + * https://bugzilla.mozilla.org/show_bug.cgi?id=1279693 + * https://bugzilla.mozilla.org/show_bug.cgi?id=1279875 + */ + switch HB_CODEPOINT_ENCODE3(blob->length, + face->table.GSUB->table.get_length (), + face->table.GPOS->table.get_length ()) + { + /* sha1sum:c5ee92f0bca4bfb7d06c4d03e8cf9f9cf75d2e8a Windows 7? timesi.ttf */ + case HB_CODEPOINT_ENCODE3 (442, 2874, 42038): + /* sha1sum:37fc8c16a0894ab7b749e35579856c73c840867b Windows 7? timesbi.ttf */ + case HB_CODEPOINT_ENCODE3 (430, 2874, 40662): + /* sha1sum:19fc45110ea6cd3cdd0a5faca256a3797a069a80 Windows 7 timesi.ttf */ + case HB_CODEPOINT_ENCODE3 (442, 2874, 39116): + /* sha1sum:6d2d3c9ed5b7de87bc84eae0df95ee5232ecde26 Windows 7 timesbi.ttf */ + case HB_CODEPOINT_ENCODE3 (430, 2874, 39374): + /* sha1sum:8583225a8b49667c077b3525333f84af08c6bcd8 OS X 10.11.3 Times New Roman Italic.ttf */ + case HB_CODEPOINT_ENCODE3 (490, 3046, 41638): + /* sha1sum:ec0f5a8751845355b7c3271d11f9918a966cb8c9 OS X 10.11.3 Times New Roman Bold Italic.ttf */ + case HB_CODEPOINT_ENCODE3 (478, 3046, 41902): + /* sha1sum:96eda93f7d33e79962451c6c39a6b51ee893ce8c tahoma.ttf from Windows 8 */ + case HB_CODEPOINT_ENCODE3 (898, 12554, 46470): + /* sha1sum:20928dc06014e0cd120b6fc942d0c3b1a46ac2bc tahomabd.ttf from Windows 8 */ + case HB_CODEPOINT_ENCODE3 (910, 12566, 47732): + /* sha1sum:4f95b7e4878f60fa3a39ca269618dfde9721a79e tahoma.ttf from Windows 8.1 */ + case HB_CODEPOINT_ENCODE3 (928, 23298, 59332): + /* sha1sum:6d400781948517c3c0441ba42acb309584b73033 tahomabd.ttf from Windows 8.1 */ + case HB_CODEPOINT_ENCODE3 (940, 23310, 60732): + /* tahoma.ttf v6.04 from Windows 8.1 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */ + case HB_CODEPOINT_ENCODE3 (964, 23836, 60072): + /* tahomabd.ttf v6.04 from Windows 8.1 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */ + case HB_CODEPOINT_ENCODE3 (976, 23832, 61456): + /* sha1sum:e55fa2dfe957a9f7ec26be516a0e30b0c925f846 tahoma.ttf from Windows 10 */ + case HB_CODEPOINT_ENCODE3 (994, 24474, 60336): + /* sha1sum:7199385abb4c2cc81c83a151a7599b6368e92343 tahomabd.ttf from Windows 10 */ + case HB_CODEPOINT_ENCODE3 (1006, 24470, 61740): + /* tahoma.ttf v6.91 from Windows 10 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */ + case HB_CODEPOINT_ENCODE3 (1006, 24576, 61346): + /* tahomabd.ttf v6.91 from Windows 10 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */ + case HB_CODEPOINT_ENCODE3 (1018, 24572, 62828): + /* sha1sum:b9c84d820c49850d3d27ec498be93955b82772b5 tahoma.ttf from Windows 10 AU */ + case HB_CODEPOINT_ENCODE3 (1006, 24576, 61352): + /* sha1sum:2bdfaab28174bdadd2f3d4200a30a7ae31db79d2 tahomabd.ttf from Windows 10 AU */ + case HB_CODEPOINT_ENCODE3 (1018, 24572, 62834): + /* sha1sum:b0d36cf5a2fbe746a3dd277bffc6756a820807a7 Tahoma.ttf from Mac OS X 10.9 */ + case HB_CODEPOINT_ENCODE3 (832, 7324, 47162): + /* sha1sum:12fc4538e84d461771b30c18b5eb6bd434e30fba Tahoma Bold.ttf from Mac OS X 10.9 */ + case HB_CODEPOINT_ENCODE3 (844, 7302, 45474): + /* sha1sum:eb8afadd28e9cf963e886b23a30b44ab4fd83acc himalaya.ttf from Windows 7 */ + case HB_CODEPOINT_ENCODE3 (180, 13054, 7254): + /* sha1sum:73da7f025b238a3f737aa1fde22577a6370f77b0 himalaya.ttf from Windows 8 */ + case HB_CODEPOINT_ENCODE3 (192, 12638, 7254): + /* sha1sum:6e80fd1c0b059bbee49272401583160dc1e6a427 himalaya.ttf from Windows 8.1 */ + case HB_CODEPOINT_ENCODE3 (192, 12690, 7254): + /* 8d9267aea9cd2c852ecfb9f12a6e834bfaeafe44 cantarell-fonts-0.0.21/otf/Cantarell-Regular.otf */ + /* 983988ff7b47439ab79aeaf9a45bd4a2c5b9d371 cantarell-fonts-0.0.21/otf/Cantarell-Oblique.otf */ + case HB_CODEPOINT_ENCODE3 (188, 248, 3852): + /* 2c0c90c6f6087ffbfea76589c93113a9cbb0e75f cantarell-fonts-0.0.21/otf/Cantarell-Bold.otf */ + /* 55461f5b853c6da88069ffcdf7f4dd3f8d7e3e6b cantarell-fonts-0.0.21/otf/Cantarell-Bold-Oblique.otf */ + case HB_CODEPOINT_ENCODE3 (188, 264, 3426): + /* d125afa82a77a6475ac0e74e7c207914af84b37a padauk-2.80/Padauk.ttf RHEL 7.2 */ + case HB_CODEPOINT_ENCODE3 (1058, 47032, 11818): + /* 0f7b80437227b90a577cc078c0216160ae61b031 padauk-2.80/Padauk-Bold.ttf RHEL 7.2*/ + case HB_CODEPOINT_ENCODE3 (1046, 47030, 12600): + /* d3dde9aa0a6b7f8f6a89ef1002e9aaa11b882290 padauk-2.80/Padauk.ttf Ubuntu 16.04 */ + case HB_CODEPOINT_ENCODE3 (1058, 71796, 16770): + /* 5f3c98ccccae8a953be2d122c1b3a77fd805093f padauk-2.80/Padauk-Bold.ttf Ubuntu 16.04 */ + case HB_CODEPOINT_ENCODE3 (1046, 71790, 17862): + /* 6c93b63b64e8b2c93f5e824e78caca555dc887c7 padauk-2.80/Padauk-book.ttf */ + case HB_CODEPOINT_ENCODE3 (1046, 71788, 17112): + /* d89b1664058359b8ec82e35d3531931125991fb9 padauk-2.80/Padauk-bookbold.ttf */ + case HB_CODEPOINT_ENCODE3 (1058, 71794, 17514): + /* 824cfd193aaf6234b2b4dc0cf3c6ef576c0d00ef padauk-3.0/Padauk-book.ttf */ + case HB_CODEPOINT_ENCODE3 (1330, 109904, 57938): + /* 91fcc10cf15e012d27571e075b3b4dfe31754a8a padauk-3.0/Padauk-bookbold.ttf */ + case HB_CODEPOINT_ENCODE3 (1330, 109904, 58972): + /* sha1sum: c26e41d567ed821bed997e937bc0c41435689e85 Padauk.ttf + * "Padauk Regular" "Version 2.5", see https://crbug.com/681813 */ + case HB_CODEPOINT_ENCODE3 (1004, 59092, 14836): + return true; + } + return false; +} + +static void +_hb_ot_layout_set_glyph_props (hb_font_t *font, + hb_buffer_t *buffer) +{ + _hb_buffer_assert_gsubgpos_vars (buffer); + + const auto &gdef = *font->face->table.GDEF; + unsigned int count = buffer->len; + hb_glyph_info_t *info = buffer->info; + for (unsigned int i = 0; i < count; i++) + { + _hb_glyph_info_set_glyph_props (&info[i], gdef.get_glyph_props (info[i].codepoint)); + _hb_glyph_info_clear_lig_props (&info[i]); + } +} + +/* Public API */ + +/** + * hb_ot_layout_has_glyph_classes: + * @face: #hb_face_t to work upon + * + * Tests whether a face has any glyph classes defined in its GDEF table. + * + * Return value: `true` if data found, `false` otherwise + * + **/ +hb_bool_t +hb_ot_layout_has_glyph_classes (hb_face_t *face) +{ + return face->table.GDEF->table->has_glyph_classes (); +} + +/** + * hb_ot_layout_get_glyph_class: + * @face: The #hb_face_t to work on + * @glyph: The #hb_codepoint_t code point to query + * + * Fetches the GDEF class of the requested glyph in the specified face. + * + * Return value: The #hb_ot_layout_glyph_class_t glyph class of the given code + * point in the GDEF table of the face. + * + * Since: 0.9.7 + **/ +hb_ot_layout_glyph_class_t +hb_ot_layout_get_glyph_class (hb_face_t *face, + hb_codepoint_t glyph) +{ + return (hb_ot_layout_glyph_class_t) face->table.GDEF->table->get_glyph_class (glyph); +} + +/** + * hb_ot_layout_get_glyphs_in_class: + * @face: The #hb_face_t to work on + * @klass: The #hb_ot_layout_glyph_class_t GDEF class to retrieve + * @glyphs: (out): The #hb_set_t set of all glyphs belonging to the requested + * class. + * + * Retrieves the set of all glyphs from the face that belong to the requested + * glyph class in the face's GDEF table. + * + * Since: 0.9.7 + **/ +void +hb_ot_layout_get_glyphs_in_class (hb_face_t *face, + hb_ot_layout_glyph_class_t klass, + hb_set_t *glyphs /* OUT */) +{ + return face->table.GDEF->table->get_glyphs_in_class (klass, glyphs); +} + +#ifndef HB_NO_LAYOUT_UNUSED +/** + * hb_ot_layout_get_attach_points: + * @face: The #hb_face_t to work on + * @glyph: The #hb_codepoint_t code point to query + * @start_offset: offset of the first attachment point to retrieve + * @point_count: (inout) (optional): Input = the maximum number of attachment points to return; + * Output = the actual number of attachment points returned (may be zero) + * @point_array: (out) (array length=point_count): The array of attachment points found for the query + * + * Fetches a list of all attachment points for the specified glyph in the GDEF + * table of the face. The list returned will begin at the offset provided. + * + * Useful if the client program wishes to cache the list. + * + * Return value: Total number of attachment points for @glyph. + * + **/ +unsigned int +hb_ot_layout_get_attach_points (hb_face_t *face, + hb_codepoint_t glyph, + unsigned int start_offset, + unsigned int *point_count /* IN/OUT */, + unsigned int *point_array /* OUT */) +{ + return face->table.GDEF->table->get_attach_points (glyph, + start_offset, + point_count, + point_array); +} +/** + * hb_ot_layout_get_ligature_carets: + * @font: The #hb_font_t to work on + * @direction: The #hb_direction_t text direction to use + * @glyph: The #hb_codepoint_t code point to query + * @start_offset: offset of the first caret position to retrieve + * @caret_count: (inout) (optional): Input = the maximum number of caret positions to return; + * Output = the actual number of caret positions returned (may be zero) + * @caret_array: (out) (array length=caret_count): The array of caret positions found for the query + * + * Fetches a list of the caret positions defined for a ligature glyph in the GDEF + * table of the font. The list returned will begin at the offset provided. + * + * Note that a ligature that is formed from n characters will have n-1 + * caret positions. The first character is not represented in the array, + * since its caret position is the glyph position. + * + * The positions returned by this function are 'unshaped', and will have to + * be fixed up for kerning that may be applied to the ligature glyph. + * + * Return value: Total number of ligature caret positions for @glyph. + * + **/ +unsigned int +hb_ot_layout_get_ligature_carets (hb_font_t *font, + hb_direction_t direction, + hb_codepoint_t glyph, + unsigned int start_offset, + unsigned int *caret_count /* IN/OUT */, + hb_position_t *caret_array /* OUT */) +{ + return font->face->table.GDEF->table->get_lig_carets (font, direction, glyph, start_offset, caret_count, caret_array); +} +#endif + + +/* + * GSUB/GPOS + */ + +bool +GSUB::is_blocklisted (hb_blob_t *blob HB_UNUSED, + hb_face_t *face) const +{ +#ifdef HB_NO_OT_LAYOUT_BLOCKLIST + return false; +#endif + return false; +} + +bool +GPOS::is_blocklisted (hb_blob_t *blob HB_UNUSED, + hb_face_t *face HB_UNUSED) const +{ +#ifdef HB_NO_OT_LAYOUT_BLOCKLIST + return false; +#endif + return false; +} + +static const OT::GSUBGPOS& +get_gsubgpos_table (hb_face_t *face, + hb_tag_t table_tag) +{ + switch (table_tag) { + case HB_OT_TAG_GSUB: return *face->table.GSUB->table; + case HB_OT_TAG_GPOS: return *face->table.GPOS->table; + default: return Null (OT::GSUBGPOS); + } +} + + +/** + * hb_ot_layout_table_get_script_tags: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @start_offset: offset of the first script tag to retrieve + * @script_count: (inout) (optional): Input = the maximum number of script tags to return; + * Output = the actual number of script tags returned (may be zero) + * @script_tags: (out) (array length=script_count): The array of #hb_tag_t script tags found for the query + * + * Fetches a list of all scripts enumerated in the specified face's GSUB table + * or GPOS table. The list returned will begin at the offset provided. + * + * Return value: Total number of script tags. + * + **/ +unsigned int +hb_ot_layout_table_get_script_tags (hb_face_t *face, + hb_tag_t table_tag, + unsigned int start_offset, + unsigned int *script_count /* IN/OUT */, + hb_tag_t *script_tags /* OUT */) +{ + const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag); + + return g.get_script_tags (start_offset, script_count, script_tags); +} + +#define HB_OT_TAG_LATIN_SCRIPT HB_TAG ('l', 'a', 't', 'n') + +/** + * hb_ot_layout_table_find_script: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @script_tag: #hb_tag_t of the script tag requested + * @script_index: (out): The index of the requested script tag + * + * Fetches the index if a given script tag in the specified face's GSUB table + * or GPOS table. + * + * Return value: `true` if the script is found, `false` otherwise + * + **/ +hb_bool_t +hb_ot_layout_table_find_script (hb_face_t *face, + hb_tag_t table_tag, + hb_tag_t script_tag, + unsigned int *script_index /* OUT */) +{ + static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX), ""); + const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag); + + if (g.find_script_index (script_tag, script_index)) + return true; + + /* try finding 'DFLT' */ + if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index)) + return false; + + /* try with 'dflt'; MS site has had typos and many fonts use it now :(. + * including many versions of DejaVu Sans Mono! */ + if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index)) + return false; + + /* try with 'latn'; some old fonts put their features there even though + they're really trying to support Thai, for example :( */ + if (g.find_script_index (HB_OT_TAG_LATIN_SCRIPT, script_index)) + return false; + + if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX; + return false; +} + +#ifndef HB_DISABLE_DEPRECATED +/** + * hb_ot_layout_table_choose_script: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @script_tags: Array of #hb_tag_t script tags + * @script_index: (out): The index of the chosen script + * @chosen_script: (out): #hb_tag_t of the chosen script + * + * Deprecated since 2.0.0 + **/ +hb_bool_t +hb_ot_layout_table_choose_script (hb_face_t *face, + hb_tag_t table_tag, + const hb_tag_t *script_tags, + unsigned int *script_index /* OUT */, + hb_tag_t *chosen_script /* OUT */) +{ + const hb_tag_t *t; + for (t = script_tags; *t; t++); + return hb_ot_layout_table_select_script (face, table_tag, t - script_tags, script_tags, script_index, chosen_script); +} +#endif + +/** + * hb_ot_layout_table_select_script: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @script_count: Number of script tags in the array + * @script_tags: Array of #hb_tag_t script tags + * @script_index: (out) (optional): The index of the requested script + * @chosen_script: (out) (optional): #hb_tag_t of the requested script + * + * Selects an OpenType script for @table_tag from the @script_tags array. + * + * If the table does not have any of the requested scripts, then `DFLT`, + * `dflt`, and `latn` tags are tried in that order. If the table still does not + * have any of these scripts, @script_index is set to + * #HB_OT_LAYOUT_NO_SCRIPT_INDEX and @chosen_script is set to #HB_TAG_NONE. + * + * Return value: + * `true` if one of the requested scripts is selected, `false` if a fallback + * script is selected or if no scripts are selected. + * + * Since: 2.0.0 + **/ +hb_bool_t +hb_ot_layout_table_select_script (hb_face_t *face, + hb_tag_t table_tag, + unsigned int script_count, + const hb_tag_t *script_tags, + unsigned int *script_index /* OUT */, + hb_tag_t *chosen_script /* OUT */) +{ + static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX), ""); + const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag); + unsigned int i; + + for (i = 0; i < script_count; i++) + { + if (g.find_script_index (script_tags[i], script_index)) + { + if (chosen_script) + *chosen_script = script_tags[i]; + return true; + } + } + + /* try finding 'DFLT' */ + if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index)) { + if (chosen_script) + *chosen_script = HB_OT_TAG_DEFAULT_SCRIPT; + return false; + } + + /* try with 'dflt'; MS site has had typos and many fonts use it now :( */ + if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index)) { + if (chosen_script) + *chosen_script = HB_OT_TAG_DEFAULT_LANGUAGE; + return false; + } + + /* try with 'latn'; some old fonts put their features there even though + they're really trying to support Thai, for example :( */ + if (g.find_script_index (HB_OT_TAG_LATIN_SCRIPT, script_index)) { + if (chosen_script) + *chosen_script = HB_OT_TAG_LATIN_SCRIPT; + return false; + } + + if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX; + if (chosen_script) + *chosen_script = HB_TAG_NONE; + return false; +} + + +/** + * hb_ot_layout_table_get_feature_tags: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @start_offset: offset of the first feature tag to retrieve + * @feature_count: (inout) (optional): Input = the maximum number of feature tags to return; + * Output = the actual number of feature tags returned (may be zero) + * @feature_tags: (out) (array length=feature_count): Array of feature tags found in the table + * + * Fetches a list of all feature tags in the given face's GSUB or GPOS table. + * Note that there might be duplicate feature tags, belonging to different + * script/language-system pairs of the table. + * + * Return value: Total number of feature tags. + * + * Since: 0.6.0 + * + **/ +unsigned int +hb_ot_layout_table_get_feature_tags (hb_face_t *face, + hb_tag_t table_tag, + unsigned int start_offset, + unsigned int *feature_count /* IN/OUT */, + hb_tag_t *feature_tags /* OUT */) +{ + const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag); + + return g.get_feature_tags (start_offset, feature_count, feature_tags); +} + + +/** + * hb_ot_layout_table_find_feature: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @feature_tag: The #hb_tag_t of the requested feature tag + * @feature_index: (out): The index of the requested feature + * + * Fetches the index for a given feature tag in the specified face's GSUB table + * or GPOS table. + * + * Return value: `true` if the feature is found, `false` otherwise + * + * Since: 0.6.0 + * + **/ +bool +hb_ot_layout_table_find_feature (hb_face_t *face, + hb_tag_t table_tag, + hb_tag_t feature_tag, + unsigned int *feature_index /* OUT */) +{ + static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX), ""); + const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag); + + unsigned int num_features = g.get_feature_count (); + for (unsigned int i = 0; i < num_features; i++) + { + if (feature_tag == g.get_feature_tag (i)) { + if (feature_index) *feature_index = i; + return true; + } + } + + if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX; + return false; +} + + +/** + * hb_ot_layout_script_get_language_tags: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @script_index: The index of the requested script tag + * @start_offset: offset of the first language tag to retrieve + * @language_count: (inout) (optional): Input = the maximum number of language tags to return; + * Output = the actual number of language tags returned (may be zero) + * @language_tags: (out) (array length=language_count): Array of language tags found in the table + * + * Fetches a list of language tags in the given face's GSUB or GPOS table, underneath + * the specified script index. The list returned will begin at the offset provided. + * + * Return value: Total number of language tags. + * + * Since: 0.6.0 + * + **/ +unsigned int +hb_ot_layout_script_get_language_tags (hb_face_t *face, + hb_tag_t table_tag, + unsigned int script_index, + unsigned int start_offset, + unsigned int *language_count /* IN/OUT */, + hb_tag_t *language_tags /* OUT */) +{ + const OT::Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index); + + return s.get_lang_sys_tags (start_offset, language_count, language_tags); +} + + +#ifndef HB_DISABLE_DEPRECATED +/** + * hb_ot_layout_script_find_language: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @script_index: The index of the requested script tag + * @language_tag: The #hb_tag_t of the requested language + * @language_index: The index of the requested language + * + * Fetches the index of a given language tag in the specified face's GSUB table + * or GPOS table, underneath the specified script tag. + * + * Return value: `true` if the language tag is found, `false` otherwise + * + * Since: 0.6.0 + * Deprecated: 2.0.0 + **/ +hb_bool_t +hb_ot_layout_script_find_language (hb_face_t *face, + hb_tag_t table_tag, + unsigned int script_index, + hb_tag_t language_tag, + unsigned int *language_index) +{ + return hb_ot_layout_script_select_language (face, + table_tag, + script_index, + 1, + &language_tag, + language_index); +} +#endif + + +/** + * hb_ot_layout_script_select_language2: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @script_index: The index of the requested script tag + * @language_count: The number of languages in the specified script + * @language_tags: The array of language tags + * @language_index: (out): The index of the chosen language + * @chosen_language: (out): #hb_tag_t of the chosen language + * + * Fetches the index of the first language tag fom @language_tags that is present + * in the specified face's GSUB or GPOS table, underneath the specified script + * index. + * + * If none of the given language tags is found, `false` is returned and + * @language_index is set to #HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX and + * @chosen_language is set to #HB_TAG_NONE. + * + * Return value: `true` if one of the given language tags is found, `false` otherwise + * + * Since: 7.0.0 + **/ +hb_bool_t +hb_ot_layout_script_select_language2 (hb_face_t *face, + hb_tag_t table_tag, + unsigned int script_index, + unsigned int language_count, + const hb_tag_t *language_tags, + unsigned int *language_index /* OUT */, + hb_tag_t *chosen_language /* OUT */) +{ + static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX), ""); + const OT::Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index); + unsigned int i; + + for (i = 0; i < language_count; i++) + { + if (s.find_lang_sys_index (language_tags[i], language_index)) + { + if (chosen_language) + *chosen_language = language_tags[i]; + return true; + } + } + + /* try finding 'dflt' */ + if (s.find_lang_sys_index (HB_OT_TAG_DEFAULT_LANGUAGE, language_index)) + { + if (chosen_language) + *chosen_language = HB_OT_TAG_DEFAULT_LANGUAGE; + return false; + } + + if (language_index) + *language_index = HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX; + if (chosen_language) + *chosen_language = HB_TAG_NONE; + return false; +} + +/** + * hb_ot_layout_script_select_language: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @script_index: The index of the requested script tag + * @language_count: The number of languages in the specified script + * @language_tags: The array of language tags + * @language_index: (out): The index of the requested language + * + * Fetches the index of the first language tag fom @language_tags that is present + * in the specified face's GSUB or GPOS table, underneath the specified script + * index. + * + * If none of the given language tags is found, `false` is returned and + * @language_index is set to the default language index. + * + * Return value: `true` if one of the given language tags is found, `false` otherwise + * + * Since: 2.0.0 + **/ +hb_bool_t +hb_ot_layout_script_select_language (hb_face_t *face, + hb_tag_t table_tag, + unsigned int script_index, + unsigned int language_count, + const hb_tag_t *language_tags, + unsigned int *language_index /* OUT */) +{ + return hb_ot_layout_script_select_language2 (face, table_tag, + script_index, + language_count, language_tags, + language_index, nullptr); +} + +/** + * hb_ot_layout_language_get_required_feature_index: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @script_index: The index of the requested script tag + * @language_index: The index of the requested language tag + * @feature_index: (out): The index of the requested feature + * + * Fetches the index of a requested feature in the given face's GSUB or GPOS table, + * underneath the specified script and language. + * + * Return value: `true` if the feature is found, `false` otherwise + * + * Since: 0.6.0 + * + **/ +hb_bool_t +hb_ot_layout_language_get_required_feature_index (hb_face_t *face, + hb_tag_t table_tag, + unsigned int script_index, + unsigned int language_index, + unsigned int *feature_index /* OUT */) +{ + return hb_ot_layout_language_get_required_feature (face, + table_tag, + script_index, + language_index, + feature_index, + nullptr); +} + + +/** + * hb_ot_layout_language_get_required_feature: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @script_index: The index of the requested script tag + * @language_index: The index of the requested language tag + * @feature_index: (out): The index of the requested feature + * @feature_tag: (out): The #hb_tag_t of the requested feature + * + * Fetches the tag of a requested feature index in the given face's GSUB or GPOS table, + * underneath the specified script and language. + * + * Return value: `true` if the feature is found, `false` otherwise + * + * Since: 0.9.30 + **/ +hb_bool_t +hb_ot_layout_language_get_required_feature (hb_face_t *face, + hb_tag_t table_tag, + unsigned int script_index, + unsigned int language_index, + unsigned int *feature_index /* OUT */, + hb_tag_t *feature_tag /* OUT */) +{ + const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag); + const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index); + + unsigned int index = l.get_required_feature_index (); + if (feature_index) *feature_index = index; + if (feature_tag) *feature_tag = g.get_feature_tag (index); + + return l.has_required_feature (); +} + + +/** + * hb_ot_layout_language_get_feature_indexes: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @script_index: The index of the requested script tag + * @language_index: The index of the requested language tag + * @start_offset: offset of the first feature tag to retrieve + * @feature_count: (inout) (optional): Input = the maximum number of feature tags to return; + * Output: the actual number of feature tags returned (may be zero) + * @feature_indexes: (out) (array length=feature_count): The array of feature indexes found for the query + * + * Fetches a list of all features in the specified face's GSUB table + * or GPOS table, underneath the specified script and language. The list + * returned will begin at the offset provided. + * + * Return value: Total number of features. + * + * Since: 0.6.0 + * + **/ +unsigned int +hb_ot_layout_language_get_feature_indexes (hb_face_t *face, + hb_tag_t table_tag, + unsigned int script_index, + unsigned int language_index, + unsigned int start_offset, + unsigned int *feature_count /* IN/OUT */, + unsigned int *feature_indexes /* OUT */) +{ + const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag); + const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index); + + return l.get_feature_indexes (start_offset, feature_count, feature_indexes); +} + + +/** + * hb_ot_layout_language_get_feature_tags: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @script_index: The index of the requested script tag + * @language_index: The index of the requested language tag + * @start_offset: offset of the first feature tag to retrieve + * @feature_count: (inout) (optional): Input = the maximum number of feature tags to return; + * Output = the actual number of feature tags returned (may be zero) + * @feature_tags: (out) (array length=feature_count): The array of #hb_tag_t feature tags found for the query + * + * Fetches a list of all features in the specified face's GSUB table + * or GPOS table, underneath the specified script and language. The list + * returned will begin at the offset provided. + * + * Return value: Total number of feature tags. + * + * Since: 0.6.0 + * + **/ +unsigned int +hb_ot_layout_language_get_feature_tags (hb_face_t *face, + hb_tag_t table_tag, + unsigned int script_index, + unsigned int language_index, + unsigned int start_offset, + unsigned int *feature_count /* IN/OUT */, + hb_tag_t *feature_tags /* OUT */) +{ + const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag); + const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index); + + static_assert ((sizeof (unsigned int) == sizeof (hb_tag_t)), ""); + unsigned int ret = l.get_feature_indexes (start_offset, feature_count, (unsigned int *) feature_tags); + + if (feature_tags) { + unsigned int count = *feature_count; + for (unsigned int i = 0; i < count; i++) + feature_tags[i] = g.get_feature_tag ((unsigned int) feature_tags[i]); + } + + return ret; +} + + +/** + * hb_ot_layout_language_find_feature: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @script_index: The index of the requested script tag + * @language_index: The index of the requested language tag + * @feature_tag: #hb_tag_t of the feature tag requested + * @feature_index: (out): The index of the requested feature + * + * Fetches the index of a given feature tag in the specified face's GSUB table + * or GPOS table, underneath the specified script and language. + * + * Return value: `true` if the feature is found, `false` otherwise + * + * Since: 0.6.0 + * + **/ +hb_bool_t +hb_ot_layout_language_find_feature (hb_face_t *face, + hb_tag_t table_tag, + unsigned int script_index, + unsigned int language_index, + hb_tag_t feature_tag, + unsigned int *feature_index /* OUT */) +{ + static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX), ""); + const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag); + const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index); + + unsigned int num_features = l.get_feature_count (); + for (unsigned int i = 0; i < num_features; i++) { + unsigned int f_index = l.get_feature_index (i); + + if (feature_tag == g.get_feature_tag (f_index)) { + if (feature_index) *feature_index = f_index; + return true; + } + } + + if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX; + return false; +} + + +/** + * hb_ot_layout_feature_get_lookups: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @feature_index: The index of the requested feature + * @start_offset: offset of the first lookup to retrieve + * @lookup_count: (inout) (optional): Input = the maximum number of lookups to return; + * Output = the actual number of lookups returned (may be zero) + * @lookup_indexes: (out) (array length=lookup_count): The array of lookup indexes found for the query + * + * Fetches a list of all lookups enumerated for the specified feature, in + * the specified face's GSUB table or GPOS table. The list returned will + * begin at the offset provided. + * + * Return value: Total number of lookups. + * + * Since: 0.9.7 + **/ +unsigned int +hb_ot_layout_feature_get_lookups (hb_face_t *face, + hb_tag_t table_tag, + unsigned int feature_index, + unsigned int start_offset, + unsigned int *lookup_count /* IN/OUT */, + unsigned int *lookup_indexes /* OUT */) +{ + return hb_ot_layout_feature_with_variations_get_lookups (face, + table_tag, + feature_index, + HB_OT_LAYOUT_NO_VARIATIONS_INDEX, + start_offset, + lookup_count, + lookup_indexes); +} + + +/** + * hb_ot_layout_table_get_lookup_count: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * + * Fetches the total number of lookups enumerated in the specified + * face's GSUB table or GPOS table. + * + * Return value: Total number of lookups. + * + * Since: 0.9.22 + **/ +unsigned int +hb_ot_layout_table_get_lookup_count (hb_face_t *face, + hb_tag_t table_tag) +{ + return get_gsubgpos_table (face, table_tag).get_lookup_count (); +} + + +struct hb_collect_features_context_t +{ + hb_collect_features_context_t (hb_face_t *face, + hb_tag_t table_tag, + hb_set_t *feature_indices_, + const hb_tag_t *features) + + : g (get_gsubgpos_table (face, table_tag)), + feature_indices (feature_indices_), + has_feature_filter (false), + script_count (0),langsys_count (0), feature_index_count (0) + { + compute_feature_filter (features); + } + + void compute_feature_filter (const hb_tag_t *features) + { + if (features == nullptr) + { + has_feature_filter = false; + return; + } + + has_feature_filter = true; + hb_set_t features_set; + for (; *features; features++) + features_set.add (*features); + + for (unsigned i = 0; i < g.get_feature_count (); i++) + { + hb_tag_t tag = g.get_feature_tag (i); + if (features_set.has (tag)) + feature_indices_filter.add(i); + } + } + + bool visited (const OT::Script &s) + { + /* We might have Null() object here. Don't want to involve + * that in the memoize. So, detect empty objects and return. */ + if (unlikely (!s.has_default_lang_sys () && + !s.get_lang_sys_count ())) + return true; + + if (script_count++ > HB_MAX_SCRIPTS) + return true; + + return visited (s, visited_script); + } + bool visited (const OT::LangSys &l) + { + /* We might have Null() object here. Don't want to involve + * that in the memoize. So, detect empty objects and return. */ + if (unlikely (!l.has_required_feature () && + !l.get_feature_count ())) + return true; + + if (langsys_count++ > HB_MAX_LANGSYS) + return true; + + return visited (l, visited_langsys); + } + + bool visited_feature_indices (unsigned count) + { + feature_index_count += count; + return feature_index_count > HB_MAX_FEATURE_INDICES; + } + + private: + template <typename T> + bool visited (const T &p, hb_set_t &visited_set) + { + hb_codepoint_t delta = (hb_codepoint_t) ((uintptr_t) &p - (uintptr_t) &g); + if (visited_set.has (delta)) + return true; + + visited_set.add (delta); + return false; + } + + public: + const OT::GSUBGPOS &g; + hb_set_t *feature_indices; + hb_set_t feature_indices_filter; + bool has_feature_filter; + + private: + hb_set_t visited_script; + hb_set_t visited_langsys; + unsigned int script_count; + unsigned int langsys_count; + unsigned int feature_index_count; +}; + +static void +langsys_collect_features (hb_collect_features_context_t *c, + const OT::LangSys &l) +{ + if (c->visited (l)) return; + + if (!c->has_feature_filter) + { + /* All features. */ + if (l.has_required_feature () && !c->visited_feature_indices (1)) + c->feature_indices->add (l.get_required_feature_index ()); + + // TODO(garretrieger): filter out indices >= feature count? + if (!c->visited_feature_indices (l.featureIndex.len)) + l.add_feature_indexes_to (c->feature_indices); + } + else + { + if (c->feature_indices_filter.is_empty()) return; + unsigned int num_features = l.get_feature_count (); + for (unsigned int i = 0; i < num_features; i++) + { + unsigned int feature_index = l.get_feature_index (i); + if (!c->feature_indices_filter.has (feature_index)) continue; + + c->feature_indices->add (feature_index); + c->feature_indices_filter.del (feature_index); + } + } +} + +static void +script_collect_features (hb_collect_features_context_t *c, + const OT::Script &s, + const hb_tag_t *languages) +{ + if (c->visited (s)) return; + + if (!languages) + { + /* All languages. */ + if (s.has_default_lang_sys ()) + langsys_collect_features (c, + s.get_default_lang_sys ()); + + + unsigned int count = s.get_lang_sys_count (); + for (unsigned int language_index = 0; language_index < count; language_index++) + langsys_collect_features (c, + s.get_lang_sys (language_index)); + } + else + { + for (; *languages; languages++) + { + unsigned int language_index; + if (s.find_lang_sys_index (*languages, &language_index)) + langsys_collect_features (c, + s.get_lang_sys (language_index)); + + } + } +} + + +/** + * hb_ot_layout_collect_features: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @scripts: (nullable) (array zero-terminated=1): The array of scripts to collect features for, + * terminated by %HB_TAG_NONE + * @languages: (nullable) (array zero-terminated=1): The array of languages to collect features for, + * terminated by %HB_TAG_NONE + * @features: (nullable) (array zero-terminated=1): The array of features to collect, + * terminated by %HB_TAG_NONE + * @feature_indexes: (out): The set of feature indexes found for the query + * + * Fetches a list of all feature indexes in the specified face's GSUB table + * or GPOS table, underneath the specified scripts, languages, and features. + * If no list of scripts is provided, all scripts will be queried. If no list + * of languages is provided, all languages will be queried. If no list of + * features is provided, all features will be queried. + * + * Since: 1.8.5 + **/ +void +hb_ot_layout_collect_features (hb_face_t *face, + hb_tag_t table_tag, + const hb_tag_t *scripts, + const hb_tag_t *languages, + const hb_tag_t *features, + hb_set_t *feature_indexes /* OUT */) +{ + hb_collect_features_context_t c (face, table_tag, feature_indexes, features); + if (!scripts) + { + /* All scripts. */ + unsigned int count = c.g.get_script_count (); + for (unsigned int script_index = 0; script_index < count; script_index++) + script_collect_features (&c, + c.g.get_script (script_index), + languages); + } + else + { + for (; *scripts; scripts++) + { + unsigned int script_index; + if (c.g.find_script_index (*scripts, &script_index)) + script_collect_features (&c, + c.g.get_script (script_index), + languages); + } + } +} + +/** + * hb_ot_layout_collect_features_map: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @script_index: The index of the requested script tag + * @language_index: The index of the requested language tag + * @feature_map: (out): The map of feature tag to feature index. + * + * Fetches the mapping from feature tags to feature indexes for + * the specified script and language. + * + * Since: 8.1.0 + **/ +void +hb_ot_layout_collect_features_map (hb_face_t *face, + hb_tag_t table_tag, + unsigned script_index, + unsigned language_index, + hb_map_t *feature_map /* OUT */) +{ + const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag); + const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index); + + unsigned int count = l.get_feature_indexes (0, nullptr, nullptr); + feature_map->alloc (count); + + /* Loop in reverse, such that earlier entries win. That emulates + * a linear search, which seems to be what other implementations do. + * We found that with arialuni_t.ttf, the "ur" language system has + * duplicate features, and the earlier ones work but not later ones. + */ + for (unsigned int i = count; i; i--) + { + unsigned feature_index = 0; + unsigned feature_count = 1; + l.get_feature_indexes (i - 1, &feature_count, &feature_index); + if (!feature_count) + break; + hb_tag_t feature_tag = g.get_feature_tag (feature_index); + feature_map->set (feature_tag, feature_index); + } +} + + +/** + * hb_ot_layout_collect_lookups: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @scripts: (nullable) (array zero-terminated=1): The array of scripts to collect lookups for, + * terminated by %HB_TAG_NONE + * @languages: (nullable) (array zero-terminated=1): The array of languages to collect lookups for, + * terminated by %HB_TAG_NONE + * @features: (nullable) (array zero-terminated=1): The array of features to collect lookups for, + * terminated by %HB_TAG_NONE + * @lookup_indexes: (out): The array of lookup indexes found for the query + * + * Fetches a list of all feature-lookup indexes in the specified face's GSUB + * table or GPOS table, underneath the specified scripts, languages, and + * features. If no list of scripts is provided, all scripts will be queried. + * If no list of languages is provided, all languages will be queried. If no + * list of features is provided, all features will be queried. + * + * Since: 0.9.8 + **/ +void +hb_ot_layout_collect_lookups (hb_face_t *face, + hb_tag_t table_tag, + const hb_tag_t *scripts, + const hb_tag_t *languages, + const hb_tag_t *features, + hb_set_t *lookup_indexes /* OUT */) +{ + const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag); + + hb_set_t feature_indexes; + hb_ot_layout_collect_features (face, table_tag, scripts, languages, features, &feature_indexes); + + for (auto feature_index : feature_indexes) + g.get_feature (feature_index).add_lookup_indexes_to (lookup_indexes); + + g.feature_variation_collect_lookups (&feature_indexes, nullptr, lookup_indexes); +} + + +#ifndef HB_NO_LAYOUT_COLLECT_GLYPHS +/** + * hb_ot_layout_lookup_collect_glyphs: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @lookup_index: The index of the feature lookup to query + * @glyphs_before: (out): Array of glyphs preceding the substitution range + * @glyphs_input: (out): Array of input glyphs that would be substituted by the lookup + * @glyphs_after: (out): Array of glyphs following the substitution range + * @glyphs_output: (out): Array of glyphs that would be the substituted output of the lookup + * + * Fetches a list of all glyphs affected by the specified lookup in the + * specified face's GSUB table or GPOS table. + * + * Since: 0.9.7 + **/ +void +hb_ot_layout_lookup_collect_glyphs (hb_face_t *face, + hb_tag_t table_tag, + unsigned int lookup_index, + hb_set_t *glyphs_before, /* OUT. May be NULL */ + hb_set_t *glyphs_input, /* OUT. May be NULL */ + hb_set_t *glyphs_after, /* OUT. May be NULL */ + hb_set_t *glyphs_output /* OUT. May be NULL */) +{ + OT::hb_collect_glyphs_context_t c (face, + glyphs_before, + glyphs_input, + glyphs_after, + glyphs_output); + + switch (table_tag) + { + case HB_OT_TAG_GSUB: + { + const OT::SubstLookup& l = face->table.GSUB->table->get_lookup (lookup_index); + l.collect_glyphs (&c); + return; + } + case HB_OT_TAG_GPOS: + { + const OT::PosLookup& l = face->table.GPOS->table->get_lookup (lookup_index); + l.collect_glyphs (&c); + return; + } + } +} +#endif + + +/* Variations support */ + + +/** + * hb_ot_layout_table_find_feature_variations: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @coords: The variation coordinates to query + * @num_coords: The number of variation coordinates + * @variations_index: (out): The array of feature variations found for the query + * + * Fetches a list of feature variations in the specified face's GSUB table + * or GPOS table, at the specified variation coordinates. + * + * Return value: `true` if feature variations were found, `false` otherwise. + * + * Since: 1.4.0 + * + **/ +hb_bool_t +hb_ot_layout_table_find_feature_variations (hb_face_t *face, + hb_tag_t table_tag, + const int *coords, + unsigned int num_coords, + unsigned int *variations_index /* out */) +{ + const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag); + + return g.find_variations_index (coords, num_coords, variations_index); +} + + +/** + * hb_ot_layout_feature_with_variations_get_lookups: + * @face: #hb_face_t to work upon + * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS + * @feature_index: The index of the feature to query + * @variations_index: The index of the feature variation to query + * @start_offset: offset of the first lookup to retrieve + * @lookup_count: (inout) (optional): Input = the maximum number of lookups to return; + * Output = the actual number of lookups returned (may be zero) + * @lookup_indexes: (out) (array length=lookup_count): The array of lookups found for the query + * + * Fetches a list of all lookups enumerated for the specified feature, in + * the specified face's GSUB table or GPOS table, enabled at the specified + * variations index. The list returned will begin at the offset provided. + * + * Return value: Total number of lookups. + * + * Since: 1.4.0 + * + **/ +unsigned int +hb_ot_layout_feature_with_variations_get_lookups (hb_face_t *face, + hb_tag_t table_tag, + unsigned int feature_index, + unsigned int variations_index, + unsigned int start_offset, + unsigned int *lookup_count /* IN/OUT */, + unsigned int *lookup_indexes /* OUT */) +{ + static_assert ((OT::FeatureVariations::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_VARIATIONS_INDEX), ""); + const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag); + + const OT::Feature &f = g.get_feature_variation (feature_index, variations_index); + + return f.get_lookup_indexes (start_offset, lookup_count, lookup_indexes); +} + + +/* + * OT::GSUB + */ + + +/** + * hb_ot_layout_has_substitution: + * @face: #hb_face_t to work upon + * + * Tests whether the specified face includes any GSUB substitutions. + * + * Return value: `true` if data found, `false` otherwise + * + * Since: 0.6.0 + * + **/ +hb_bool_t +hb_ot_layout_has_substitution (hb_face_t *face) +{ + return face->table.GSUB->table->has_data (); +} + + +/** + * hb_ot_layout_lookup_would_substitute: + * @face: #hb_face_t to work upon + * @lookup_index: The index of the lookup to query + * @glyphs: The sequence of glyphs to query for substitution + * @glyphs_length: The length of the glyph sequence + * @zero_context: #hb_bool_t indicating whether pre-/post-context are disallowed + * in substitutions + * + * Tests whether a specified lookup in the specified face would + * trigger a substitution on the given glyph sequence. + * + * Return value: `true` if a substitution would be triggered, `false` otherwise + * + * Since: 0.9.7 + **/ +hb_bool_t +hb_ot_layout_lookup_would_substitute (hb_face_t *face, + unsigned int lookup_index, + const hb_codepoint_t *glyphs, + unsigned int glyphs_length, + hb_bool_t zero_context) +{ + auto &gsub = face->table.GSUB; + if (unlikely (lookup_index >= gsub->lookup_count)) return false; + OT::hb_would_apply_context_t c (face, glyphs, glyphs_length, (bool) zero_context); + + const OT::SubstLookup& l = gsub->table->get_lookup (lookup_index); + auto *accel = gsub->get_accel (lookup_index); + return accel && l.would_apply (&c, accel); +} + + +/** + * hb_ot_layout_substitute_start: + * @font: #hb_font_t to use + * @buffer: #hb_buffer_t buffer to work upon + * + * Called before substitution lookups are performed, to ensure that glyph + * class and other properties are set on the glyphs in the buffer. + * + **/ +void +hb_ot_layout_substitute_start (hb_font_t *font, + hb_buffer_t *buffer) +{ + _hb_ot_layout_set_glyph_props (font, buffer); +} + +/** + * hb_ot_layout_lookup_substitute_closure: + * @face: #hb_face_t to work upon + * @lookup_index: index of the feature lookup to query + * @glyphs: (out): Array of glyphs comprising the transitive closure of the lookup + * + * Compute the transitive closure of glyphs needed for a + * specified lookup. + * + * Since: 0.9.7 + **/ +void +hb_ot_layout_lookup_substitute_closure (hb_face_t *face, + unsigned int lookup_index, + hb_set_t *glyphs /* OUT */) +{ + hb_map_t done_lookups_glyph_count; + hb_hashmap_t<unsigned, hb::unique_ptr<hb_set_t>> done_lookups_glyph_set; + OT::hb_closure_context_t c (face, glyphs, &done_lookups_glyph_count, &done_lookups_glyph_set); + + const OT::SubstLookup& l = face->table.GSUB->table->get_lookup (lookup_index); + + l.closure (&c, lookup_index); +} + +/** + * hb_ot_layout_lookups_substitute_closure: + * @face: #hb_face_t to work upon + * @lookups: The set of lookups to query + * @glyphs: (out): Array of glyphs comprising the transitive closure of the lookups + * + * Compute the transitive closure of glyphs needed for all of the + * provided lookups. + * + * Since: 1.8.1 + **/ +void +hb_ot_layout_lookups_substitute_closure (hb_face_t *face, + const hb_set_t *lookups, + hb_set_t *glyphs /* OUT */) +{ + hb_map_t done_lookups_glyph_count; + hb_hashmap_t<unsigned, hb::unique_ptr<hb_set_t>> done_lookups_glyph_set; + OT::hb_closure_context_t c (face, glyphs, &done_lookups_glyph_count, &done_lookups_glyph_set); + const GSUB& gsub = *face->table.GSUB->table; + + unsigned int iteration_count = 0; + unsigned int glyphs_length; + do + { + c.reset_lookup_visit_count (); + glyphs_length = glyphs->get_population (); + if (lookups) + { + for (auto lookup_index : *lookups) + gsub.get_lookup (lookup_index).closure (&c, lookup_index); + } + else + { + for (unsigned int i = 0; i < gsub.get_lookup_count (); i++) + gsub.get_lookup (i).closure (&c, i); + } + } while (iteration_count++ <= HB_CLOSURE_MAX_STAGES && + glyphs_length != glyphs->get_population ()); +} + +/* + * GPOS + */ + + +/** + * hb_ot_layout_has_positioning: + * @face: #hb_face_t to work upon + * + * Tests whether the specified face includes any GPOS positioning. + * + * Return value: `true` if the face has GPOS data, `false` otherwise + * + **/ +hb_bool_t +hb_ot_layout_has_positioning (hb_face_t *face) +{ + return face->table.GPOS->table->has_data (); +} + +/** + * hb_ot_layout_position_start: + * @font: #hb_font_t to use + * @buffer: #hb_buffer_t buffer to work upon + * + * Called before positioning lookups are performed, to ensure that glyph + * attachment types and glyph-attachment chains are set for the glyphs in the buffer. + * + **/ +void +hb_ot_layout_position_start (hb_font_t *font, hb_buffer_t *buffer) +{ + GPOS::position_start (font, buffer); +} + + +/** + * hb_ot_layout_position_finish_advances: + * @font: #hb_font_t to use + * @buffer: #hb_buffer_t buffer to work upon + * + * Called after positioning lookups are performed, to finish glyph advances. + * + **/ +void +hb_ot_layout_position_finish_advances (hb_font_t *font, hb_buffer_t *buffer) +{ + GPOS::position_finish_advances (font, buffer); +} + +/** + * hb_ot_layout_position_finish_offsets: + * @font: #hb_font_t to use + * @buffer: #hb_buffer_t buffer to work upon + * + * Called after positioning lookups are performed, to finish glyph offsets. + * + **/ +void +hb_ot_layout_position_finish_offsets (hb_font_t *font, hb_buffer_t *buffer) +{ + GPOS::position_finish_offsets (font, buffer); +} + + +#ifndef HB_NO_LAYOUT_FEATURE_PARAMS +/** + * hb_ot_layout_get_size_params: + * @face: #hb_face_t to work upon + * @design_size: (out): The design size of the face + * @subfamily_id: (out): The identifier of the face within the font subfamily + * @subfamily_name_id: (out): The ‘name’ table name ID of the face within the font subfamily + * @range_start: (out): The minimum size of the recommended size range for the face + * @range_end: (out): The maximum size of the recommended size range for the face + * + * Fetches optical-size feature data (i.e., the `size` feature from GPOS). Note that + * the subfamily_id and the subfamily name string (accessible via the subfamily_name_id) + * as used here are defined as pertaining only to fonts within a font family that differ + * specifically in their respective size ranges; other ways to differentiate fonts within + * a subfamily are not covered by the `size` feature. + * + * For more information on this distinction, see the [`size` feature documentation]( + * https://docs.microsoft.com/en-us/typography/opentype/spec/features_pt#tag-size). + * + * Return value: `true` if data found, `false` otherwise + * + * Since: 0.9.10 + **/ +hb_bool_t +hb_ot_layout_get_size_params (hb_face_t *face, + unsigned int *design_size, /* OUT. May be NULL */ + unsigned int *subfamily_id, /* OUT. May be NULL */ + hb_ot_name_id_t *subfamily_name_id, /* OUT. May be NULL */ + unsigned int *range_start, /* OUT. May be NULL */ + unsigned int *range_end /* OUT. May be NULL */) +{ + const GPOS &gpos = *face->table.GPOS->table; + const hb_tag_t tag = HB_TAG ('s','i','z','e'); + + unsigned int num_features = gpos.get_feature_count (); + for (unsigned int i = 0; i < num_features; i++) + { + if (tag == gpos.get_feature_tag (i)) + { + const OT::Feature &f = gpos.get_feature (i); + const OT::FeatureParamsSize ¶ms = f.get_feature_params ().get_size_params (tag); + + if (params.designSize) + { + if (design_size) *design_size = params.designSize; + if (subfamily_id) *subfamily_id = params.subfamilyID; + if (subfamily_name_id) *subfamily_name_id = params.subfamilyNameID; + if (range_start) *range_start = params.rangeStart; + if (range_end) *range_end = params.rangeEnd; + + return true; + } + } + } + + if (design_size) *design_size = 0; + if (subfamily_id) *subfamily_id = 0; + if (subfamily_name_id) *subfamily_name_id = HB_OT_NAME_ID_INVALID; + if (range_start) *range_start = 0; + if (range_end) *range_end = 0; + + return false; +} + + +/** + * hb_ot_layout_feature_get_name_ids: + * @face: #hb_face_t to work upon + * @table_tag: table tag to query, "GSUB" or "GPOS". + * @feature_index: index of feature to query. + * @label_id: (out) (optional): The ‘name’ table name ID that specifies a string + * for a user-interface label for this feature. (May be NULL.) + * @tooltip_id: (out) (optional): The ‘name’ table name ID that specifies a string + * that an application can use for tooltip text for this + * feature. (May be NULL.) + * @sample_id: (out) (optional): The ‘name’ table name ID that specifies sample text + * that illustrates the effect of this feature. (May be NULL.) + * @num_named_parameters: (out) (optional): Number of named parameters. (May be zero.) + * @first_param_id: (out) (optional): The first ‘name’ table name ID used to specify + * strings for user-interface labels for the feature + * parameters. (Must be zero if numParameters is zero.) + * + * Fetches name indices from feature parameters for "Stylistic Set" ('ssXX') or + * "Character Variant" ('cvXX') features. + * + * Return value: `true` if data found, `false` otherwise + * + * Since: 2.0.0 + **/ +hb_bool_t +hb_ot_layout_feature_get_name_ids (hb_face_t *face, + hb_tag_t table_tag, + unsigned int feature_index, + hb_ot_name_id_t *label_id, /* OUT. May be NULL */ + hb_ot_name_id_t *tooltip_id, /* OUT. May be NULL */ + hb_ot_name_id_t *sample_id, /* OUT. May be NULL */ + unsigned int *num_named_parameters, /* OUT. May be NULL */ + hb_ot_name_id_t *first_param_id /* OUT. May be NULL */) +{ + const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag); + + hb_tag_t feature_tag = g.get_feature_tag (feature_index); + const OT::Feature &f = g.get_feature (feature_index); + + const OT::FeatureParams &feature_params = f.get_feature_params (); + if (&feature_params != &Null (OT::FeatureParams)) + { + const OT::FeatureParamsStylisticSet& ss_params = + feature_params.get_stylistic_set_params (feature_tag); + if (&ss_params != &Null (OT::FeatureParamsStylisticSet)) /* ssXX */ + { + if (label_id) *label_id = ss_params.uiNameID; + // ssXX features don't have the rest + if (tooltip_id) *tooltip_id = HB_OT_NAME_ID_INVALID; + if (sample_id) *sample_id = HB_OT_NAME_ID_INVALID; + if (num_named_parameters) *num_named_parameters = 0; + if (first_param_id) *first_param_id = HB_OT_NAME_ID_INVALID; + return true; + } + const OT::FeatureParamsCharacterVariants& cv_params = + feature_params.get_character_variants_params (feature_tag); + if (&cv_params != &Null (OT::FeatureParamsCharacterVariants)) /* cvXX */ + { + if (label_id) *label_id = cv_params.featUILableNameID; + if (tooltip_id) *tooltip_id = cv_params.featUITooltipTextNameID; + if (sample_id) *sample_id = cv_params.sampleTextNameID; + if (num_named_parameters) *num_named_parameters = cv_params.numNamedParameters; + if (first_param_id) *first_param_id = cv_params.firstParamUILabelNameID; + return true; + } + } + + if (label_id) *label_id = HB_OT_NAME_ID_INVALID; + if (tooltip_id) *tooltip_id = HB_OT_NAME_ID_INVALID; + if (sample_id) *sample_id = HB_OT_NAME_ID_INVALID; + if (num_named_parameters) *num_named_parameters = 0; + if (first_param_id) *first_param_id = HB_OT_NAME_ID_INVALID; + return false; +} +/** + * hb_ot_layout_feature_get_characters: + * @face: #hb_face_t to work upon + * @table_tag: table tag to query, "GSUB" or "GPOS". + * @feature_index: index of feature to query. + * @start_offset: offset of the first character to retrieve + * @char_count: (inout) (optional): Input = the maximum number of characters to return; + * Output = the actual number of characters returned (may be zero) + * @characters: (out caller-allocates) (array length=char_count): A buffer pointer. + * The Unicode codepoints of the characters for which this feature provides + * glyph variants. + * + * Fetches a list of the characters defined as having a variant under the specified + * "Character Variant" ("cvXX") feature tag. + * + * Return value: Number of total sample characters in the cvXX feature. + * + * Since: 2.0.0 + **/ +unsigned int +hb_ot_layout_feature_get_characters (hb_face_t *face, + hb_tag_t table_tag, + unsigned int feature_index, + unsigned int start_offset, + unsigned int *char_count, /* IN/OUT. May be NULL */ + hb_codepoint_t *characters /* OUT. May be NULL */) +{ + const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag); + return g.get_feature (feature_index) + .get_feature_params () + .get_character_variants_params(g.get_feature_tag (feature_index)) + .get_characters (start_offset, char_count, characters); +} +#endif + + +/* + * Parts of different types are implemented here such that they have direct + * access to GSUB/GPOS lookups. + */ + + +struct GSUBProxy +{ + static constexpr unsigned table_index = 0u; + static constexpr bool always_inplace = false; + typedef OT::SubstLookup Lookup; + + GSUBProxy (hb_face_t *face) : + accel (*face->table.GSUB) {} + + const GSUB::accelerator_t &accel; +}; + +struct GPOSProxy +{ + static constexpr unsigned table_index = 1u; + static constexpr bool always_inplace = true; + typedef OT::PosLookup Lookup; + + GPOSProxy (hb_face_t *face) : + accel (*face->table.GPOS) {} + + const GPOS::accelerator_t &accel; +}; + + +static inline bool +apply_forward (OT::hb_ot_apply_context_t *c, + const OT::hb_ot_layout_lookup_accelerator_t &accel, + unsigned subtable_count) +{ + bool use_cache = accel.cache_enter (c); + + bool ret = false; + hb_buffer_t *buffer = c->buffer; + while (buffer->idx < buffer->len && buffer->successful) + { + bool applied = false; + if (accel.digest.may_have (buffer->cur().codepoint) && + (buffer->cur().mask & c->lookup_mask) && + c->check_glyph_property (&buffer->cur(), c->lookup_props)) + { + applied = accel.apply (c, subtable_count, use_cache); + } + + if (applied) + ret = true; + else + (void) buffer->next_glyph (); + } + + if (use_cache) + accel.cache_leave (c); + + return ret; +} + +static inline bool +apply_backward (OT::hb_ot_apply_context_t *c, + const OT::hb_ot_layout_lookup_accelerator_t &accel, + unsigned subtable_count) +{ + bool ret = false; + hb_buffer_t *buffer = c->buffer; + do + { + if (accel.digest.may_have (buffer->cur().codepoint) && + (buffer->cur().mask & c->lookup_mask) && + c->check_glyph_property (&buffer->cur(), c->lookup_props)) + ret |= accel.apply (c, subtable_count, false); + + /* The reverse lookup doesn't "advance" cursor (for good reason). */ + buffer->idx--; + + } + while ((int) buffer->idx >= 0); + return ret; +} + +template <typename Proxy> +static inline bool +apply_string (OT::hb_ot_apply_context_t *c, + const typename Proxy::Lookup &lookup, + const OT::hb_ot_layout_lookup_accelerator_t &accel) +{ + hb_buffer_t *buffer = c->buffer; + unsigned subtable_count = lookup.get_subtable_count (); + + if (unlikely (!buffer->len || !c->lookup_mask)) + return false; + + bool ret = false; + + c->set_lookup_props (lookup.get_props ()); + + if (likely (!lookup.is_reverse ())) + { + /* in/out forward substitution/positioning */ + if (!Proxy::always_inplace) + buffer->clear_output (); + + buffer->idx = 0; + ret = apply_forward (c, accel, subtable_count); + + if (!Proxy::always_inplace) + buffer->sync (); + } + else + { + /* in-place backward substitution/positioning */ + assert (!buffer->have_output); + buffer->idx = buffer->len - 1; + ret = apply_backward (c, accel, subtable_count); + } + + return ret; +} + +template <typename Proxy> +inline void hb_ot_map_t::apply (const Proxy &proxy, + const hb_ot_shape_plan_t *plan, + hb_font_t *font, + hb_buffer_t *buffer) const +{ + const unsigned int table_index = proxy.table_index; + unsigned int i = 0; + OT::hb_ot_apply_context_t c (table_index, font, buffer, proxy.accel.get_blob ()); + c.set_recurse_func (Proxy::Lookup::template dispatch_recurse_func<OT::hb_ot_apply_context_t>); + + for (unsigned int stage_index = 0; stage_index < stages[table_index].length; stage_index++) + { + const stage_map_t *stage = &stages[table_index][stage_index]; + for (; i < stage->last_lookup; i++) + { + auto &lookup = lookups[table_index][i]; + + unsigned int lookup_index = lookup.index; + + auto *accel = proxy.accel.get_accel (lookup_index); + if (unlikely (!accel)) continue; + + if (buffer->messaging () && + !buffer->message (font, "start lookup %u feature '%c%c%c%c'", lookup_index, HB_UNTAG (lookup.feature_tag))) continue; + + /* c.digest is a digest of all the current glyphs in the buffer + * (plus some past glyphs). + * + * Only try applying the lookup if there is any overlap. */ + if (accel->digest.may_have (c.digest)) + { + c.set_lookup_index (lookup_index); + c.set_lookup_mask (lookup.mask, false); + c.set_auto_zwj (lookup.auto_zwj, false); + c.set_auto_zwnj (lookup.auto_zwnj, false); + c.set_random (lookup.random); + c.set_per_syllable (lookup.per_syllable, false); + /* apply_string's set_lookup_props initializes the iterators. */ + + apply_string<Proxy> (&c, + proxy.accel.table->get_lookup (lookup_index), + *accel); + } + else if (buffer->messaging ()) + (void) buffer->message (font, "skipped lookup %u feature '%c%c%c%c' because no glyph matches", lookup_index, HB_UNTAG (lookup.feature_tag)); + + if (buffer->messaging ()) + (void) buffer->message (font, "end lookup %u feature '%c%c%c%c'", lookup_index, HB_UNTAG (lookup.feature_tag)); + } + + if (stage->pause_func) + { + if (stage->pause_func (plan, font, buffer)) + { + /* Refresh working buffer digest since buffer changed. */ + c.digest = buffer->digest (); + } + } + } +} + +void hb_ot_map_t::substitute (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const +{ + GSUBProxy proxy (font->face); + if (buffer->messaging () && + !buffer->message (font, "start table GSUB script tag '%c%c%c%c'", HB_UNTAG (chosen_script[0]))) return; + apply (proxy, plan, font, buffer); + if (buffer->messaging ()) + (void) buffer->message (font, "end table GSUB script tag '%c%c%c%c'", HB_UNTAG (chosen_script[0])); +} + +void hb_ot_map_t::position (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const +{ + GPOSProxy proxy (font->face); + if (buffer->messaging () && + !buffer->message (font, "start table GPOS script tag '%c%c%c%c'", HB_UNTAG (chosen_script[1]))) return; + apply (proxy, plan, font, buffer); + if (buffer->messaging ()) + (void) buffer->message (font, "end table GPOS script tag '%c%c%c%c'", HB_UNTAG (chosen_script[1])); +} + +void +hb_ot_layout_substitute_lookup (OT::hb_ot_apply_context_t *c, + const OT::SubstLookup &lookup, + const OT::hb_ot_layout_lookup_accelerator_t &accel) +{ + apply_string<GSUBProxy> (c, lookup, accel); +} + +#ifndef HB_NO_BASE + +static void +choose_base_tags (hb_script_t script, + hb_language_t language, + hb_tag_t *script_tag, + hb_tag_t *language_tag) +{ + hb_tag_t script_tags[HB_OT_MAX_TAGS_PER_SCRIPT]; + unsigned script_count = ARRAY_LENGTH (script_tags); + + hb_tag_t language_tags[HB_OT_MAX_TAGS_PER_LANGUAGE]; + unsigned language_count = ARRAY_LENGTH (language_tags); + + hb_ot_tags_from_script_and_language (script, language, + &script_count, script_tags, + &language_count, language_tags); + + *script_tag = script_count ? script_tags[script_count - 1] : HB_OT_TAG_DEFAULT_SCRIPT; + *language_tag = language_count ? language_tags[language_count - 1] : HB_OT_TAG_DEFAULT_LANGUAGE; +} + +/** + * hb_ot_layout_get_font_extents: + * @font: a font + * @direction: text direction. + * @script_tag: script tag. + * @language_tag: language tag. + * @extents: (out) (nullable): font extents if found. + * + * Fetches script/language-specific font extents. These values are + * looked up in the `BASE` table's `MinMax` records. + * + * If no such extents are found, the default extents for the font are + * fetched. As such, the return value of this function can for the + * most part be ignored. Note that the per-script/language extents + * do not have a line-gap value, and the line-gap is set to zero in + * that case. + * + * Return value: `true` if found script/language-specific font extents. + * + * Since: 8.0.0 + **/ +hb_bool_t +hb_ot_layout_get_font_extents (hb_font_t *font, + hb_direction_t direction, + hb_tag_t script_tag, + hb_tag_t language_tag, + hb_font_extents_t *extents) +{ + hb_position_t min, max; + if (font->face->table.BASE->get_min_max (font, direction, script_tag, language_tag, HB_TAG_NONE, + &min, &max)) + { + if (extents) + { + extents->ascender = max; + extents->descender = min; + extents->line_gap = 0; + } + return true; + } + + hb_font_get_extents_for_direction (font, direction, extents); + return false; +} + +/** + * hb_ot_layout_get_font_extents2: + * @font: a font + * @direction: text direction. + * @script: script. + * @language: (nullable): language. + * @extents: (out) (nullable): font extents if found. + * + * Fetches script/language-specific font extents. These values are + * looked up in the `BASE` table's `MinMax` records. + * + * If no such extents are found, the default extents for the font are + * fetched. As such, the return value of this function can for the + * most part be ignored. Note that the per-script/language extents + * do not have a line-gap value, and the line-gap is set to zero in + * that case. + * + * This function is like hb_ot_layout_get_font_extents() but takes + * #hb_script_t and #hb_language_t instead of OpenType #hb_tag_t. + * + * Return value: `true` if found script/language-specific font extents. + * + * Since: 8.0.0 + **/ +hb_bool_t +hb_ot_layout_get_font_extents2 (hb_font_t *font, + hb_direction_t direction, + hb_script_t script, + hb_language_t language, + hb_font_extents_t *extents) +{ + hb_tag_t script_tag, language_tag; + choose_base_tags (script, language, &script_tag, &language_tag); + return hb_ot_layout_get_font_extents (font, + direction, + script_tag, + language_tag, + extents); +} + +/** + * hb_ot_layout_get_horizontal_baseline_tag_for_script: + * @script: a script tag. + * + * Fetches the dominant horizontal baseline tag used by @script. + * + * Return value: dominant baseline tag for the @script. + * + * Since: 4.0.0 + **/ +hb_ot_layout_baseline_tag_t +hb_ot_layout_get_horizontal_baseline_tag_for_script (hb_script_t script) +{ + /* Keep in sync with hb_ot_layout_get_baseline_with_fallback */ + switch ((int) script) + { + /* Unicode-1.1 additions */ + case HB_SCRIPT_BENGALI: + case HB_SCRIPT_DEVANAGARI: + case HB_SCRIPT_GUJARATI: + case HB_SCRIPT_GURMUKHI: + /* Unicode-2.0 additions */ + case HB_SCRIPT_TIBETAN: + /* Unicode-4.0 additions */ + case HB_SCRIPT_LIMBU: + /* Unicode-4.1 additions */ + case HB_SCRIPT_SYLOTI_NAGRI: + /* Unicode-5.0 additions */ + case HB_SCRIPT_PHAGS_PA: + /* Unicode-5.2 additions */ + case HB_SCRIPT_MEETEI_MAYEK: + /* Unicode-6.1 additions */ + case HB_SCRIPT_SHARADA: + case HB_SCRIPT_TAKRI: + /* Unicode-7.0 additions */ + case HB_SCRIPT_MODI: + case HB_SCRIPT_SIDDHAM: + case HB_SCRIPT_TIRHUTA: + /* Unicode-9.0 additions */ + case HB_SCRIPT_MARCHEN: + case HB_SCRIPT_NEWA: + /* Unicode-10.0 additions */ + case HB_SCRIPT_SOYOMBO: + case HB_SCRIPT_ZANABAZAR_SQUARE: + /* Unicode-11.0 additions */ + case HB_SCRIPT_DOGRA: + case HB_SCRIPT_GUNJALA_GONDI: + /* Unicode-12.0 additions */ + case HB_SCRIPT_NANDINAGARI: + return HB_OT_LAYOUT_BASELINE_TAG_HANGING; + + /* Unicode-1.1 additions */ + case HB_SCRIPT_HANGUL: + case HB_SCRIPT_HAN: + case HB_SCRIPT_HIRAGANA: + case HB_SCRIPT_KATAKANA: + /* Unicode-3.0 additions */ + case HB_SCRIPT_BOPOMOFO: + /* Unicode-9.0 additions */ + case HB_SCRIPT_TANGUT: + /* Unicode-10.0 additions */ + case HB_SCRIPT_NUSHU: + /* Unicode-13.0 additions */ + case HB_SCRIPT_KHITAN_SMALL_SCRIPT: + return HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_BOTTOM_OR_LEFT; + + default: + return HB_OT_LAYOUT_BASELINE_TAG_ROMAN; + } +} + +/** + * hb_ot_layout_get_baseline: + * @font: a font + * @baseline_tag: a baseline tag + * @direction: text direction. + * @script_tag: script tag. + * @language_tag: language tag, currently unused. + * @coord: (out) (nullable): baseline value if found. + * + * Fetches a baseline value from the face. + * + * Return value: `true` if found baseline value in the font. + * + * Since: 2.6.0 + **/ +hb_bool_t +hb_ot_layout_get_baseline (hb_font_t *font, + hb_ot_layout_baseline_tag_t baseline_tag, + hb_direction_t direction, + hb_tag_t script_tag, + hb_tag_t language_tag, + hb_position_t *coord /* OUT. May be NULL. */) +{ + return font->face->table.BASE->get_baseline (font, baseline_tag, direction, script_tag, language_tag, coord); +} + +/** + * hb_ot_layout_get_baseline2: + * @font: a font + * @baseline_tag: a baseline tag + * @direction: text direction. + * @script: script. + * @language: (nullable): language, currently unused. + * @coord: (out) (nullable): baseline value if found. + * + * Fetches a baseline value from the face. + * + * This function is like hb_ot_layout_get_baseline() but takes + * #hb_script_t and #hb_language_t instead of OpenType #hb_tag_t. + * + * Return value: `true` if found baseline value in the font. + * + * Since: 8.0.0 + **/ +hb_bool_t +hb_ot_layout_get_baseline2 (hb_font_t *font, + hb_ot_layout_baseline_tag_t baseline_tag, + hb_direction_t direction, + hb_script_t script, + hb_language_t language, + hb_position_t *coord /* OUT. May be NULL. */) +{ + hb_tag_t script_tag, language_tag; + choose_base_tags (script, language, &script_tag, &language_tag); + return hb_ot_layout_get_baseline (font, + baseline_tag, + direction, + script_tag, + language_tag, + coord); +} + +/** + * hb_ot_layout_get_baseline_with_fallback: + * @font: a font + * @baseline_tag: a baseline tag + * @direction: text direction. + * @script_tag: script tag. + * @language_tag: language tag, currently unused. + * @coord: (out): baseline value if found. + * + * Fetches a baseline value from the face, and synthesizes + * it if the font does not have it. + * + * Since: 4.0.0 + **/ +void +hb_ot_layout_get_baseline_with_fallback (hb_font_t *font, + hb_ot_layout_baseline_tag_t baseline_tag, + hb_direction_t direction, + hb_tag_t script_tag, + hb_tag_t language_tag, + hb_position_t *coord /* OUT */) +{ + if (hb_ot_layout_get_baseline (font, + baseline_tag, + direction, + script_tag, + language_tag, + coord)) + return; + + /* Synthesize missing baselines. + * See https://www.w3.org/TR/css-inline-3/#baseline-synthesis-fonts + */ + switch (baseline_tag) + { + case HB_OT_LAYOUT_BASELINE_TAG_ROMAN: + *coord = 0; // FIXME origin ? + break; + + case HB_OT_LAYOUT_BASELINE_TAG_MATH: + { + hb_codepoint_t glyph; + hb_glyph_extents_t extents; + if (HB_DIRECTION_IS_HORIZONTAL (direction) && + (hb_font_get_nominal_glyph (font, 0x2212u, &glyph) || + hb_font_get_nominal_glyph (font, '-', &glyph)) && + hb_font_get_glyph_extents (font, glyph, &extents)) + { + *coord = extents.y_bearing + extents.height / 2; + } + else + { + hb_position_t x_height = font->y_scale / 2; +#ifndef HB_NO_METRICS + hb_ot_metrics_get_position_with_fallback (font, HB_OT_METRICS_TAG_X_HEIGHT, &x_height); +#endif + *coord = x_height / 2; + } + } + break; + + case HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_TOP_OR_RIGHT: + case HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_BOTTOM_OR_LEFT: + { + hb_position_t embox_top, embox_bottom; + + hb_ot_layout_get_baseline_with_fallback (font, + HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_TOP_OR_RIGHT, + direction, + script_tag, + language_tag, + &embox_top); + hb_ot_layout_get_baseline_with_fallback (font, + HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_BOTTOM_OR_LEFT, + direction, + script_tag, + language_tag, + &embox_bottom); + + if (baseline_tag == HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_TOP_OR_RIGHT) + *coord = embox_top + (embox_bottom - embox_top) / 10; + else + *coord = embox_bottom + (embox_top - embox_bottom) / 10; + } + break; + + case HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_TOP_OR_RIGHT: + if (hb_ot_layout_get_baseline (font, + HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_BOTTOM_OR_LEFT, + direction, + script_tag, + language_tag, + coord)) + *coord += HB_DIRECTION_IS_HORIZONTAL (direction) ? font->y_scale : font->x_scale; + else + { + hb_font_extents_t font_extents; + hb_font_get_extents_for_direction (font, direction, &font_extents); + *coord = font_extents.ascender; + } + break; + + case HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_BOTTOM_OR_LEFT: + if (hb_ot_layout_get_baseline (font, + HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_TOP_OR_RIGHT, + direction, + script_tag, + language_tag, + coord)) + *coord -= HB_DIRECTION_IS_HORIZONTAL (direction) ? font->y_scale : font->x_scale; + else + { + hb_font_extents_t font_extents; + hb_font_get_extents_for_direction (font, direction, &font_extents); + *coord = font_extents.descender; + } + break; + + case HB_OT_LAYOUT_BASELINE_TAG_HANGING: + if (HB_DIRECTION_IS_HORIZONTAL (direction)) + { + hb_codepoint_t ch; + hb_codepoint_t glyph; + hb_glyph_extents_t extents; + + /* Keep in sync with hb_ot_layout_get_horizontal_baseline_for_script */ + switch ((int) script_tag) + { + /* Unicode-1.1 additions */ + case HB_SCRIPT_BENGALI: ch = 0x0995u; break; + case HB_SCRIPT_DEVANAGARI: ch = 0x0915u; break; + case HB_SCRIPT_GUJARATI: ch = 0x0a95u; break; + case HB_SCRIPT_GURMUKHI: ch = 0x0a15u; break; + /* Unicode-2.0 additions */ + case HB_SCRIPT_TIBETAN: ch = 0x0f40u; break; + /* Unicode-4.0 additions */ + case HB_SCRIPT_LIMBU: ch = 0x1901u; break; + /* Unicode-4.1 additions */ + case HB_SCRIPT_SYLOTI_NAGRI: ch = 0xa807u; break; + /* Unicode-5.0 additions */ + case HB_SCRIPT_PHAGS_PA: ch = 0xa840u; break; + /* Unicode-5.2 additions */ + case HB_SCRIPT_MEETEI_MAYEK: ch = 0xabc0u; break; + /* Unicode-6.1 additions */ + case HB_SCRIPT_SHARADA: ch = 0x11191u; break; + case HB_SCRIPT_TAKRI: ch = 0x1168cu; break; + /* Unicode-7.0 additions */ + case HB_SCRIPT_MODI: ch = 0x1160eu;break; + case HB_SCRIPT_SIDDHAM: ch = 0x11590u; break; + case HB_SCRIPT_TIRHUTA: ch = 0x1148fu; break; + /* Unicode-9.0 additions */ + case HB_SCRIPT_MARCHEN: ch = 0x11c72u; break; + case HB_SCRIPT_NEWA: ch = 0x1140eu; break; + /* Unicode-10.0 additions */ + case HB_SCRIPT_SOYOMBO: ch = 0x11a5cu; break; + case HB_SCRIPT_ZANABAZAR_SQUARE: ch = 0x11a0bu; break; + /* Unicode-11.0 additions */ + case HB_SCRIPT_DOGRA: ch = 0x1180au; break; + case HB_SCRIPT_GUNJALA_GONDI: ch = 0x11d6cu; break; + /* Unicode-12.0 additions */ + case HB_SCRIPT_NANDINAGARI: ch = 0x119b0u; break; + default: ch = 0; break; + } + + if (ch && + hb_font_get_nominal_glyph (font, ch, &glyph) && + hb_font_get_glyph_extents (font, glyph, &extents)) + *coord = extents.y_bearing; + else + *coord = font->y_scale * 6 / 10; // FIXME makes assumptions about origin + } + else + *coord = font->x_scale * 6 / 10; // FIXME makes assumptions about origin + break; + + case HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_CENTRAL: + { + hb_position_t top, bottom; + hb_ot_layout_get_baseline_with_fallback (font, + HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_TOP_OR_RIGHT, + direction, + script_tag, + language_tag, + &top); + hb_ot_layout_get_baseline_with_fallback (font, + HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_BOTTOM_OR_LEFT, + direction, + script_tag, + language_tag, + &bottom); + *coord = (top + bottom) / 2; + + } + break; + + case HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_CENTRAL: + { + hb_position_t top, bottom; + hb_ot_layout_get_baseline_with_fallback (font, + HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_TOP_OR_RIGHT, + direction, + script_tag, + language_tag, + &top); + hb_ot_layout_get_baseline_with_fallback (font, + HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_BOTTOM_OR_LEFT, + direction, + script_tag, + language_tag, + &bottom); + *coord = (top + bottom) / 2; + + } + break; + + case _HB_OT_LAYOUT_BASELINE_TAG_MAX_VALUE: + default: + *coord = 0; + break; + } +} + +/** + * hb_ot_layout_get_baseline_with_fallback2: + * @font: a font + * @baseline_tag: a baseline tag + * @direction: text direction. + * @script: script. + * @language: (nullable): language, currently unused. + * @coord: (out): baseline value if found. + * + * Fetches a baseline value from the face, and synthesizes + * it if the font does not have it. + * + * This function is like hb_ot_layout_get_baseline_with_fallback() but takes + * #hb_script_t and #hb_language_t instead of OpenType #hb_tag_t. + * + * Since: 8.0.0 + **/ +void +hb_ot_layout_get_baseline_with_fallback2 (hb_font_t *font, + hb_ot_layout_baseline_tag_t baseline_tag, + hb_direction_t direction, + hb_script_t script, + hb_language_t language, + hb_position_t *coord /* OUT */) +{ + hb_tag_t script_tag, language_tag; + choose_base_tags (script, language, &script_tag, &language_tag); + hb_ot_layout_get_baseline_with_fallback (font, + baseline_tag, + direction, + script_tag, + language_tag, + coord); +} + +#endif + + +struct hb_get_glyph_alternates_dispatch_t : + hb_dispatch_context_t<hb_get_glyph_alternates_dispatch_t, unsigned> +{ + static return_t default_return_value () { return 0; } + bool stop_sublookup_iteration (return_t r) const { return r; } + + private: + template <typename T, typename ...Ts> auto + _dispatch (const T &obj, hb_priority<1>, Ts&&... ds) HB_AUTO_RETURN + ( obj.get_glyph_alternates (std::forward<Ts> (ds)...) ) + template <typename T, typename ...Ts> auto + _dispatch (const T &obj, hb_priority<0>, Ts&&... ds) HB_AUTO_RETURN + ( default_return_value () ) + public: + template <typename T, typename ...Ts> auto + dispatch (const T &obj, Ts&&... ds) HB_AUTO_RETURN + ( _dispatch (obj, hb_prioritize, std::forward<Ts> (ds)...) ) +}; + +#ifndef HB_NO_LAYOUT_RARELY_USED +/** + * hb_ot_layout_lookup_get_glyph_alternates: + * @face: a face. + * @lookup_index: index of the feature lookup to query. + * @glyph: a glyph id. + * @start_offset: starting offset. + * @alternate_count: (inout) (optional): Input = the maximum number of alternate glyphs to return; + * Output = the actual number of alternate glyphs returned (may be zero). + * @alternate_glyphs: (out caller-allocates) (array length=alternate_count): A glyphs buffer. + * Alternate glyphs associated with the glyph id. + * + * Fetches alternates of a glyph from a given GSUB lookup index. + * + * Return value: Total number of alternates found in the specific lookup index for the given glyph id. + * + * Since: 2.6.8 + **/ +HB_EXTERN unsigned +hb_ot_layout_lookup_get_glyph_alternates (hb_face_t *face, + unsigned lookup_index, + hb_codepoint_t glyph, + unsigned start_offset, + unsigned *alternate_count /* IN/OUT. May be NULL. */, + hb_codepoint_t *alternate_glyphs /* OUT. May be NULL. */) +{ + hb_get_glyph_alternates_dispatch_t c; + const OT::SubstLookup &lookup = face->table.GSUB->table->get_lookup (lookup_index); + auto ret = lookup.dispatch (&c, glyph, start_offset, alternate_count, alternate_glyphs); + if (!ret && alternate_count) *alternate_count = 0; + return ret; +} + + +struct hb_position_single_dispatch_t : + hb_dispatch_context_t<hb_position_single_dispatch_t, bool> +{ + static return_t default_return_value () { return false; } + bool stop_sublookup_iteration (return_t r) const { return r; } + + private: + template <typename T, typename ...Ts> auto + _dispatch (const T &obj, hb_priority<1>, Ts&&... ds) HB_AUTO_RETURN + ( obj.position_single (std::forward<Ts> (ds)...) ) + template <typename T, typename ...Ts> auto + _dispatch (const T &obj, hb_priority<0>, Ts&&... ds) HB_AUTO_RETURN + ( default_return_value () ) + public: + template <typename T, typename ...Ts> auto + dispatch (const T &obj, Ts&&... ds) HB_AUTO_RETURN + ( _dispatch (obj, hb_prioritize, std::forward<Ts> (ds)...) ) +}; + +/** + * hb_ot_layout_lookup_get_optical_bound: + * @font: a font. + * @lookup_index: index of the feature lookup to query. + * @direction: edge of the glyph to query. + * @glyph: a glyph id. + * + * Fetches the optical bound of a glyph positioned at the margin of text. + * The direction identifies which edge of the glyph to query. + * + * Return value: Adjustment value. Negative values mean the glyph will stick out of the margin. + * + * Since: 5.3.0 + **/ +hb_position_t +hb_ot_layout_lookup_get_optical_bound (hb_font_t *font, + unsigned lookup_index, + hb_direction_t direction, + hb_codepoint_t glyph) +{ + const OT::PosLookup &lookup = font->face->table.GPOS->table->get_lookup (lookup_index); + hb_blob_t *blob = font->face->table.GPOS->get_blob (); + hb_glyph_position_t pos = {0}; + hb_position_single_dispatch_t c; + lookup.dispatch (&c, font, blob, direction, glyph, pos); + hb_position_t ret = 0; + switch (direction) + { + case HB_DIRECTION_LTR: + ret = pos.x_offset; + break; + case HB_DIRECTION_RTL: + ret = pos.x_advance - pos.x_offset; + break; + case HB_DIRECTION_TTB: + ret = pos.y_offset; + break; + case HB_DIRECTION_BTT: + ret = pos.y_advance - pos.y_offset; + break; + case HB_DIRECTION_INVALID: + default: + break; + } + return ret; +} +#endif + + +#endif |