harfbuzz/src/hb-ot-layout.cc

505 lines
14 KiB
C++

/*
* Copyright © 1998-2004 David Turner and Werner Lemberg
* Copyright © 2006 Behdad Esfahbod
* Copyright © 2007,2008,2009 Red Hat, 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
*/
#include "hb-ot-layout-private.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-maxp-table.hh"
#include <stdlib.h>
#include <string.h>
hb_ot_layout_t *
_hb_ot_layout_create (hb_face_t *face)
{
/* TODO Remove this object altogether */
hb_ot_layout_t *layout = (hb_ot_layout_t *) calloc (1, sizeof (hb_ot_layout_t));
layout->gdef_blob = Sanitizer<GDEF>::sanitize (hb_face_reference_table (face, HB_OT_TAG_GDEF));
layout->gdef = Sanitizer<GDEF>::lock_instance (layout->gdef_blob);
layout->gsub_blob = Sanitizer<GSUB>::sanitize (hb_face_reference_table (face, HB_OT_TAG_GSUB));
layout->gsub = Sanitizer<GSUB>::lock_instance (layout->gsub_blob);
layout->gpos_blob = Sanitizer<GPOS>::sanitize (hb_face_reference_table (face, HB_OT_TAG_GPOS));
layout->gpos = Sanitizer<GPOS>::lock_instance (layout->gpos_blob);
return layout;
}
void
_hb_ot_layout_destroy (hb_ot_layout_t *layout)
{
hb_blob_destroy (layout->gdef_blob);
hb_blob_destroy (layout->gsub_blob);
hb_blob_destroy (layout->gpos_blob);
free (layout);
}
static inline const GDEF&
_get_gdef (hb_face_t *face)
{
return likely (face->ot_layout && face->ot_layout->gdef) ? *face->ot_layout->gdef : Null(GDEF);
}
static inline const GSUB&
_get_gsub (hb_face_t *face)
{
return likely (face->ot_layout && face->ot_layout->gsub) ? *face->ot_layout->gsub : Null(GSUB);
}
static inline const GPOS&
_get_gpos (hb_face_t *face)
{
return likely (face->ot_layout && face->ot_layout->gpos) ? *face->ot_layout->gpos : Null(GPOS);
}
/*
* GDEF
*/
hb_bool_t
hb_ot_layout_has_glyph_classes (hb_face_t *face)
{
return _get_gdef (face).has_glyph_classes ();
}
unsigned int
_hb_ot_layout_get_glyph_property (hb_face_t *face,
hb_glyph_info_t *info)
{
if (!info->props_cache())
{
const GDEF &gdef = _get_gdef (face);
info->props_cache() = gdef.get_glyph_props (info->codepoint);
}
return info->props_cache();
}
static hb_bool_t
_hb_ot_layout_match_properties (hb_face_t *face,
hb_codepoint_t codepoint,
unsigned int glyph_props,
unsigned int lookup_props)
{
/* Not covered, if, for example, glyph class is ligature and
* lookup_props includes LookupFlags::IgnoreLigatures
*/
if (glyph_props & lookup_props & LookupFlag::IgnoreFlags)
return false;
if (glyph_props & HB_OT_LAYOUT_GLYPH_CLASS_MARK)
{
/* If using mark filtering sets, the high short of
* lookup_props has the set index.
*/
if (lookup_props & LookupFlag::UseMarkFilteringSet)
return _get_gdef (face).mark_set_covers (lookup_props >> 16, codepoint);
/* The second byte of lookup_props has the meaning
* "ignore marks of attachment type different than
* the attachment type specified."
*/
if (lookup_props & LookupFlag::MarkAttachmentType && glyph_props & LookupFlag::MarkAttachmentType)
return (lookup_props & LookupFlag::MarkAttachmentType) == (glyph_props & LookupFlag::MarkAttachmentType);
}
return true;
}
hb_bool_t
_hb_ot_layout_check_glyph_property (hb_face_t *face,
hb_glyph_info_t *ginfo,
unsigned int lookup_props,
unsigned int *property_out)
{
unsigned int property;
property = _hb_ot_layout_get_glyph_property (face, ginfo);
(void) (property_out && (*property_out = property));
return _hb_ot_layout_match_properties (face, ginfo->codepoint, property, lookup_props);
}
hb_bool_t
_hb_ot_layout_skip_mark (hb_face_t *face,
hb_glyph_info_t *ginfo,
unsigned int lookup_props,
unsigned int *property_out)
{
unsigned int property;
property = _hb_ot_layout_get_glyph_property (face, ginfo);
(void) (property_out && (*property_out = property));
/* If it's a mark, skip it we don't accept it. */
if (unlikely (property & HB_OT_LAYOUT_GLYPH_CLASS_MARK))
return !_hb_ot_layout_match_properties (face, ginfo->codepoint, property, lookup_props);
/* If not a mark, don't skip. */
return false;
}
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 _get_gdef (face).get_attach_points (glyph, start_offset, point_count, point_array);
}
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 */,
int *caret_array /* OUT */)
{
return _get_gdef (font->face).get_lig_carets (font, direction, glyph, start_offset, caret_count, caret_array);
}
/*
* GSUB/GPOS
*/
static const GSUBGPOS&
get_gsubgpos_table (hb_face_t *face,
hb_tag_t table_tag)
{
switch (table_tag) {
case HB_OT_TAG_GSUB: return _get_gsub (face);
case HB_OT_TAG_GPOS: return _get_gpos (face);
default: return Null(GSUBGPOS);
}
}
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 GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
return g.get_script_tags (start_offset, script_count, script_tags);
}
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)
{
ASSERT_STATIC (Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
const 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;
if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
return FALSE;
}
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,
hb_tag_t *chosen_script)
{
ASSERT_STATIC (Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
while (*script_tags)
{
if (g.find_script_index (*script_tags, script_index)) {
if (chosen_script)
*chosen_script = *script_tags;
return TRUE;
}
script_tags++;
}
/* 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 :( */
#define HB_OT_TAG_LATIN_SCRIPT HB_TAG ('l', 'a', 't', 'n')
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;
}
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 GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
return g.get_feature_tags (start_offset, feature_count, feature_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 Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
return s.get_lang_sys_tags (start_offset, language_count, language_tags);
}
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)
{
ASSERT_STATIC (Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX);
const Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
if (s.find_lang_sys_index (language_tag, language_index))
return TRUE;
/* try with 'dflt'; MS site has had typos and many fonts use it now :( */
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_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)
{
const LangSys &l = get_gsubgpos_table (face, table_tag).get_script (script_index).get_lang_sys (language_index);
if (feature_index) *feature_index = l.get_required_feature_index ();
return l.has_required_feature ();
}
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 GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
return l.get_feature_indexes (start_offset, feature_count, feature_indexes);
}
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 GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
ASSERT_STATIC (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_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)
{
ASSERT_STATIC (Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX);
const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
const 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;
}
unsigned int
hb_ot_layout_feature_get_lookup_indexes (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 */)
{
const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
const Feature &f = g.get_feature (feature_index);
return f.get_lookup_indexes (start_offset, lookup_count, lookup_indexes);
}
/*
* GSUB
*/
hb_bool_t
hb_ot_layout_has_substitution (hb_face_t *face)
{
return &_get_gsub (face) != &Null(GSUB);
}
void
hb_ot_layout_substitute_start (hb_buffer_t *buffer)
{
GSUB::substitute_start (buffer);
}
hb_bool_t
hb_ot_layout_substitute_lookup (hb_face_t *face,
hb_buffer_t *buffer,
unsigned int lookup_index,
hb_mask_t mask)
{
return _get_gsub (face).substitute_lookup (face, buffer, lookup_index, mask);
}
void
hb_ot_layout_substitute_finish (hb_buffer_t *buffer HB_UNUSED)
{
GSUB::substitute_finish (buffer);
}
/*
* GPOS
*/
hb_bool_t
hb_ot_layout_has_positioning (hb_face_t *face)
{
return &_get_gpos (face) != &Null(GPOS);
}
void
hb_ot_layout_position_start (hb_buffer_t *buffer)
{
GPOS::position_start (buffer);
}
hb_bool_t
hb_ot_layout_position_lookup (hb_font_t *font,
hb_buffer_t *buffer,
unsigned int lookup_index,
hb_mask_t mask)
{
return _get_gpos (font->face).position_lookup (font, buffer, lookup_index, mask);
}
void
hb_ot_layout_position_finish (hb_buffer_t *buffer)
{
GPOS::position_finish (buffer);
}