harfbuzz/src/hb-ot-layout.cc

2478 lines
80 KiB
C++
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/*
* 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.
**/
/*
* 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]);
}
}
/* 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: REPLACEME
**/
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 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: (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 (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, 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 (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 ());
}
/*
* 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 &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 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);
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);
c.set_auto_zwj (lookup.auto_zwj);
c.set_auto_zwnj (lookup.auto_zwnj);
c.set_random (lookup.random);
c.set_per_syllable (lookup.per_syllable);
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")) return;
apply (proxy, plan, font, buffer);
if (buffer->messaging ())
(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->messaging () &&
!buffer->message (font, "start table GPOS")) return;
apply (proxy, plan, font, buffer);
if (buffer->messaging ())
(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; }
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_glyph_position_t pos = {0};
hb_position_single_dispatch_t c;
lookup.dispatch (&c, font, 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