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flutter / third_party / harfbuzz / f41945e313ca053253bfd339186b87c977da3bf3 / . / src / hb-ot-layout.cc
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/*
* 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" // Just so we compile it; unused otherwise.
#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.
/**
* 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.
**/
/*
* 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 OT::GDEF &gdef = *font->face->table.GDEF->table;
unsigned int count = buffer->len;
for (unsigned int i = 0; i < count; i++)
{
_hb_glyph_info_set_glyph_props (&buffer->info[i], gdef.get_glyph_props (buffer->info[i].codepoint));
_hb_glyph_info_clear_lig_props (&buffer->info[i]);
buffer->info[i].syllable() = 0;
}
}
/* 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
OT::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
OT::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 requested script tag
* @chosen_script: (out): #hb_tag_t of the script tag requested
*
* 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 and @chosen_script are set to
* #HB_OT_LAYOUT_NO_SCRIPT_INDEX.
*
* 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_OT_LAYOUT_NO_SCRIPT_INDEX;
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.
*
* Return value: Total number of feature tags.
*
**/
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
**/
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.
*
**/
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_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 */)
{
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))
return true;
}
/* try finding 'dflt' */
if (s.find_lang_sys_index (HB_OT_TAG_DEFAULT_LANGUAGE, language_index))
return false;
if (language_index)
*language_index = HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX;
return false;
}
/**
* 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
*
**/
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.
**/
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.
**/
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
*
**/
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: The array of scripts to collect features for
* @languages: The array of languages to collect features for
* @features: The array of features to collect
* @feature_indexes: (out): The array 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_lookups:
* @face: #hb_face_t to work upon
* @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
* @scripts: The array of scripts to collect lookups for
* @languages: The array of languages to collect lookups for
* @features: The array of features to collect lookups for
* @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 (hb_codepoint_t feature_index = HB_SET_VALUE_INVALID;
hb_set_next (&feature_indexes, &feature_index);)
g.get_feature (feature_index).add_lookup_indexes_to (lookup_indexes);
g.feature_variation_collect_lookups (&feature_indexes, 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.
*
**/
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.
*
**/
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
*
**/
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)
{
if (unlikely (lookup_index >= face->table.GSUB->lookup_count)) return false;
OT::hb_would_apply_context_t c (face, glyphs, glyphs_length, (bool) zero_context);
const OT::SubstLookup& l = face->table.GSUB->table->get_lookup (lookup_index);
return l.would_apply (&c, &face->table.GSUB->accels[lookup_index]);
}
/**
* 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);
}
void
hb_ot_layout_delete_glyphs_inplace (hb_buffer_t *buffer,
bool (*filter) (const hb_glyph_info_t *info))
{
/* Merge clusters and delete filtered glyphs.
* NOTE! We can't use out-buffer as we have positioning data. */
unsigned int j = 0;
unsigned int count = buffer->len;
hb_glyph_info_t *info = buffer->info;
hb_glyph_position_t *pos = buffer->pos;
for (unsigned int i = 0; i < count; i++)
{
if (filter (&info[i]))
{
/* Merge clusters.
* Same logic as buffer->delete_glyph(), but for in-place removal. */
unsigned int cluster = info[i].cluster;
if (i + 1 < count && cluster == info[i + 1].cluster)
continue; /* Cluster survives; do nothing. */
if (j)
{
/* Merge cluster backward. */
if (cluster < info[j - 1].cluster)
{
unsigned int mask = info[i].mask;
unsigned int old_cluster = info[j - 1].cluster;
for (unsigned k = j; k && info[k - 1].cluster == old_cluster; k--)
buffer->set_cluster (info[k - 1], cluster, mask);
}
continue;
}
if (i + 1 < count)
buffer->merge_clusters (i, i + 2); /* Merge cluster forward. */
continue;
}
if (j != i)
{
info[j] = info[i];
pos[j] = pos[i];
}
j++;
}
buffer->len = j;
}
/**
* 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_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);
for (auto _ : done_lookups_glyph_set.iter ())
hb_set_destroy (_.second);
}
/**
* 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_set_t *> done_lookups_glyph_set;
OT::hb_closure_context_t c (face, glyphs, &done_lookups_glyph_count, &done_lookups_glyph_set);
const OT::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 (hb_codepoint_t lookup_index = HB_SET_VALUE_INVALID; hb_set_next (lookups, &lookup_index);)
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 ());
for (auto _ : done_lookups_glyph_set.iter ())
hb_set_destroy (_.second);
}
/*
* OT::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)
{
OT::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)
{
OT::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)
{
OT::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 OT::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 &params = 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 inplace = false;
typedef OT::SubstLookup Lookup;
GSUBProxy (hb_face_t *face) :
table (*face->table.GSUB->table),
accels (face->table.GSUB->accels) {}
const OT::GSUB &table;
const OT::hb_ot_layout_lookup_accelerator_t *accels;
};
struct GPOSProxy
{
static constexpr unsigned table_index = 1u;
static constexpr bool inplace = true;
typedef OT::PosLookup Lookup;
GPOSProxy (hb_face_t *face) :
table (*face->table.GPOS->table),
accels (face->table.GPOS->accels) {}
const OT::GPOS &table;
const OT::hb_ot_layout_lookup_accelerator_t *accels;
};
static inline bool
apply_forward (OT::hb_ot_apply_context_t *c,
const OT::hb_ot_layout_lookup_accelerator_t &accel)
{
bool ret = false;
hb_buffer_t *buffer = c->buffer;
while (buffer->idx < buffer->len && buffer->successful)
{
bool applied = false;
if (accel.may_have (buffer->cur().codepoint) &&
(buffer->cur().mask & c->lookup_mask) &&
c->check_glyph_property (&buffer->cur(), c->lookup_props))
{
applied = accel.apply (c);
}
if (applied)
ret = true;
else
(void) buffer->next_glyph ();
}
return ret;
}
static inline bool
apply_backward (OT::hb_ot_apply_context_t *c,
const OT::hb_ot_layout_lookup_accelerator_t &accel)
{
bool ret = false;
hb_buffer_t *buffer = c->buffer;
do
{
if (accel.may_have (buffer->cur().codepoint) &&
(buffer->cur().mask & c->lookup_mask) &&
c->check_glyph_property (&buffer->cur(), c->lookup_props))
ret |= accel.apply (c);
/* The reverse lookup doesn't "advance" cursor (for good reason). */
buffer->idx--;
}
while ((int) buffer->idx >= 0);
return ret;
}
template <typename Proxy>
static inline void
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;
if (unlikely (!buffer->len || !c->lookup_mask))
return;
c->set_lookup_props (lookup.get_props ());
if (likely (!lookup.is_reverse ()))
{
/* in/out forward substitution/positioning */
if (!Proxy::inplace)
buffer->clear_output ();
buffer->idx = 0;
apply_forward (c, accel);
if (!Proxy::inplace)
buffer->sync ();
}
else
{
/* in-place backward substitution/positioning */
assert (!buffer->have_output);
buffer->idx = buffer->len - 1;
apply_backward (c, accel);
}
}
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);
c.set_recurse_func (Proxy::Lookup::apply_recurse_func);
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++)
{
unsigned int lookup_index = lookups[table_index][i].index;
if (!buffer->message (font, "start lookup %d", lookup_index)) continue;
c.set_lookup_index (lookup_index);
c.set_lookup_mask (lookups[table_index][i].mask);
c.set_auto_zwj (lookups[table_index][i].auto_zwj);
c.set_auto_zwnj (lookups[table_index][i].auto_zwnj);
c.set_random (lookups[table_index][i].random);
apply_string<Proxy> (&c,
proxy.table.get_lookup (lookup_index),
proxy.accels[lookup_index]);
(void) buffer->message (font, "end lookup %d", lookup_index);
}
if (stage->pause_func)
stage->pause_func (plan, font, buffer);
}
}
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->message (font, "start table GSUB")) return;
apply (proxy, plan, font, buffer);
(void) buffer->message (font, "end table GSUB");
}
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->message (font, "start table GPOS")) return;
apply (proxy, plan, font, buffer);
(void) buffer->message (font, "end table GPOS");
}
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
/**
* 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_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;
}
}
#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; }
hb_face_t *face;
hb_get_glyph_alternates_dispatch_t (hb_face_t *face) :
face (face) {}
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)...) )
};
/**
* 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 (face);
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;
}
#endif