harfbuzz/src/hb-ot-layout.cc

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/*
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* Copyright (C) 1998-2004 David Turner and Werner Lemberg
* Copyright (C) 2006 Behdad Esfahbod
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* Copyright (C) 2007,2008 Red Hat, Inc.
*
* This is part of HarfBuzz, an OpenType Layout engine 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
*/
#define HB_OT_LAYOUT_CC
#include "hb-ot-layout.h"
#include "hb-ot-layout-private.h"
#include "hb-ot-layout-open-private.h"
#include "hb-ot-layout-gdef-private.h"
#include "hb-ot-layout-gsub-private.h"
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/* XXX */
#include "harfbuzz-buffer-private.h"
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#include <stdlib.h>
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#include <string.h>
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struct _hb_ot_layout_t {
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const GDEF *gdef;
const GSUB *gsub;
const /*XXX*/GSUBGPOS *gpos;
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struct {
unsigned char *klasses;
unsigned int len;
} new_gdef;
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/* TODO add max-nesting-level here? */
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};
hb_ot_layout_t *
hb_ot_layout_create (void)
{
hb_ot_layout_t *layout = (hb_ot_layout_t *) calloc (1, sizeof (hb_ot_layout_t));
layout->gdef = &NullGDEF;
layout->gsub = &NullGSUB;
layout->gpos = &/*XXX*/NullGSUBGPOS;
return layout;
}
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hb_ot_layout_t *
hb_ot_layout_create_for_data (const char *font_data,
int face_index)
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{
hb_ot_layout_t *layout;
if (HB_UNLIKELY (font_data == NULL))
return hb_ot_layout_create ();
layout = (hb_ot_layout_t *) calloc (1, sizeof (hb_ot_layout_t));
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const OpenTypeFontFile &font = OpenTypeFontFile::get_for_data (font_data);
const OpenTypeFontFace &face = font.get_face (face_index);
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layout->gdef = &GDEF::get_for_data (font.get_table_data (face.get_table_by_tag (GDEF::Tag)));
layout->gsub = &GSUB::get_for_data (font.get_table_data (face.get_table_by_tag (GSUB::Tag)));
layout->gpos = &/*XXX*/GSUBGPOS::get_for_data (font.get_table_data (face.get_table_by_tag (/*XXX*/GSUBGPOS::GPOSTag)));
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return layout;
}
void
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hb_ot_layout_destroy (hb_ot_layout_t *layout)
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{
free (layout);
}
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/*
* GDEF
*/
hb_bool_t
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hb_ot_layout_has_font_glyph_classes (hb_ot_layout_t *layout)
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{
return layout->gdef->has_glyph_classes ();
}
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HB_OT_LAYOUT_INTERNAL hb_bool_t
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_hb_ot_layout_has_new_glyph_classes (hb_ot_layout_t *layout)
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{
return layout->new_gdef.len > 0;
}
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HB_OT_LAYOUT_INTERNAL hb_ot_layout_glyph_properties_t
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_hb_ot_layout_get_glyph_properties (hb_ot_layout_t *layout,
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hb_codepoint_t glyph)
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{
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hb_ot_layout_class_t klass;
/* TODO old harfbuzz doesn't always parse mark attachments as it says it was
* introduced without a version bump, so it may not be safe */
klass = layout->gdef->get_mark_attachment_type (glyph);
if (klass)
return klass << 8;
klass = layout->gdef->get_glyph_class (glyph);
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if (!klass && glyph < layout->new_gdef.len)
klass = layout->new_gdef.klasses[glyph];
switch (klass) {
default:
case GDEF::UnclassifiedGlyph: return HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED;
case GDEF::BaseGlyph: return HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH;
case GDEF::LigatureGlyph: return HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE;
case GDEF::MarkGlyph: return HB_OT_LAYOUT_GLYPH_CLASS_MARK;
case GDEF::ComponentGlyph: return HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT;
}
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}
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HB_OT_LAYOUT_INTERNAL hb_bool_t
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_hb_ot_layout_check_glyph_properties (hb_ot_layout_t *layout,
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HB_GlyphItem gitem,
hb_ot_layout_lookup_flags_t lookup_flags,
hb_ot_layout_glyph_properties_t *property)
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{
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hb_ot_layout_glyph_class_t basic_glyph_class;
hb_ot_layout_glyph_properties_t desired_attachment_class;
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if (gitem->gproperties == HB_BUFFER_GLYPH_PROPERTIES_UNKNOWN)
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{
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gitem->gproperties = *property = _hb_ot_layout_get_glyph_properties (layout, gitem->gindex);
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if (gitem->gproperties == HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED)
return false;
}
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*property = gitem->gproperties;
/* If the glyph was found in the MarkAttachmentClass table,
* then that class value is the high byte of the result,
* otherwise the low byte contains the basic type of the glyph
* as defined by the GlyphClassDef table.
*/
if (*property & LookupFlag::MarkAttachmentType)
basic_glyph_class = HB_OT_LAYOUT_GLYPH_CLASS_MARK;
else
basic_glyph_class = (hb_ot_layout_glyph_class_t) *property;
/* Not covered, if, for example, basic_glyph_class
* is HB_GDEF_LIGATURE and lookup_flags includes LookupFlags::IgnoreLigatures
*/
if (lookup_flags & basic_glyph_class)
return false;
/* The high byte of lookup_flags has the meaning
* "ignore marks of attachment type different than
* the attachment type specified."
*/
desired_attachment_class = lookup_flags & LookupFlag::MarkAttachmentType;
if (desired_attachment_class)
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{
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if (basic_glyph_class == HB_OT_LAYOUT_GLYPH_CLASS_MARK &&
*property != desired_attachment_class )
return false;
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}
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return true;
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}
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hb_ot_layout_glyph_class_t
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hb_ot_layout_get_glyph_class (hb_ot_layout_t *layout,
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hb_codepoint_t glyph)
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{
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hb_ot_layout_glyph_properties_t properties;
hb_ot_layout_class_t klass;
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properties = _hb_ot_layout_get_glyph_properties (layout, glyph);
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if (properties & 0xFF00)
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return HB_OT_LAYOUT_GLYPH_CLASS_MARK;
return (hb_ot_layout_glyph_class_t) properties;
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}
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void
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hb_ot_layout_set_glyph_class (hb_ot_layout_t *layout,
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hb_codepoint_t glyph,
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hb_ot_layout_glyph_class_t klass)
{
/* TODO optimize this, similar to old harfbuzz code for example */
hb_ot_layout_class_t gdef_klass;
int len = layout->new_gdef.len;
if (glyph >= len) {
int new_len;
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unsigned char *new_klasses;
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new_len = len == 0 ? 120 : 2 * len;
if (new_len > 65535)
new_len = 65535;
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new_klasses = (unsigned char *) realloc (layout->new_gdef.klasses, new_len * sizeof (unsigned char));
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if (G_UNLIKELY (!new_klasses))
return;
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memset (new_klasses + len, 0, new_len - len);
layout->new_gdef.klasses = new_klasses;
layout->new_gdef.len = new_len;
}
switch (klass) {
default:
case HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED: gdef_klass = GDEF::UnclassifiedGlyph; break;
case HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH: gdef_klass = GDEF::BaseGlyph; break;
case HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE: gdef_klass = GDEF::LigatureGlyph; break;
case HB_OT_LAYOUT_GLYPH_CLASS_MARK: gdef_klass = GDEF::MarkGlyph; break;
case HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT: gdef_klass = GDEF::ComponentGlyph; break;
}
layout->new_gdef.klasses[glyph] = gdef_klass;
return;
}
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void
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hb_ot_layout_build_glyph_classes (hb_ot_layout_t *layout,
uint16_t num_total_glyphs,
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hb_codepoint_t *glyphs,
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unsigned char *klasses,
uint16_t count)
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{
int i;
if (G_UNLIKELY (!count || !glyphs || !klasses))
return;
if (layout->new_gdef.len == 0) {
layout->new_gdef.klasses = (unsigned char *) calloc (num_total_glyphs, sizeof (unsigned char));
layout->new_gdef.len = count;
}
for (i = 0; i < count; i++)
hb_ot_layout_set_glyph_class (layout, glyphs[i], (hb_ot_layout_glyph_class_t) klasses[i]);
}
/*
* GSUB/GPOS
*/
static const GSUBGPOS&
get_gsubgpos_table (hb_ot_layout_t *layout,
hb_ot_layout_table_type_t table_type)
{
switch (table_type) {
case HB_OT_LAYOUT_TABLE_TYPE_GSUB: return *(layout->gsub);
case HB_OT_LAYOUT_TABLE_TYPE_GPOS: return *(layout->gpos);
default: return NullGSUBGPOS;
}
}
unsigned int
hb_ot_layout_table_get_script_count (hb_ot_layout_t *layout,
hb_ot_layout_table_type_t table_type)
{
const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
return g.get_script_count ();
}
hb_tag_t
hb_ot_layout_table_get_script_tag (hb_ot_layout_t *layout,
hb_ot_layout_table_type_t table_type,
unsigned int script_index)
{
const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
return g.get_script_tag (script_index);
}
hb_bool_t
hb_ot_layout_table_find_script (hb_ot_layout_t *layout,
hb_ot_layout_table_type_t table_type,
hb_tag_t script_tag,
unsigned int *script_index)
{
ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
if (g.find_script_index (script_tag, script_index))
return TRUE;
/* try finding 'DFLT' */
if (g.find_script_index (HB_OT_LAYOUT_TAG_DEFAULT_SCRIPT, script_index))
return FALSE;
/* try with 'dflt'; MS site has had typos and many fonts use it now :( */
if (g.find_script_index (HB_OT_LAYOUT_TAG_DEFAULT_LANGUAGE, script_index))
return FALSE;
if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
return FALSE;
}
unsigned int
hb_ot_layout_table_get_feature_count (hb_ot_layout_t *layout,
hb_ot_layout_table_type_t table_type)
{
const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
return g.get_feature_count ();
}
hb_tag_t
hb_ot_layout_table_get_feature_tag (hb_ot_layout_t *layout,
hb_ot_layout_table_type_t table_type,
unsigned int feature_index)
{
const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
return g.get_feature_tag (feature_index);
}
hb_bool_t
hb_ot_layout_table_find_feature (hb_ot_layout_t *layout,
hb_ot_layout_table_type_t table_type,
hb_tag_t feature_tag,
unsigned int *feature_index)
{
ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX);
const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
if (g.find_feature_index (feature_tag, feature_index))
return TRUE;
if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
return FALSE;
}
unsigned int
hb_ot_layout_table_get_lookup_count (hb_ot_layout_t *layout,
hb_ot_layout_table_type_t table_type)
{
const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
return g.get_lookup_count ();
}
unsigned int
hb_ot_layout_script_get_language_count (hb_ot_layout_t *layout,
hb_ot_layout_table_type_t table_type,
unsigned int script_index)
{
const Script &s = get_gsubgpos_table (layout, table_type).get_script (script_index);
return s.get_lang_sys_count ();
}
hb_tag_t
hb_ot_layout_script_get_language_tag (hb_ot_layout_t *layout,
hb_ot_layout_table_type_t table_type,
unsigned int script_index,
unsigned int language_index)
{
const Script &s = get_gsubgpos_table (layout, table_type).get_script (script_index);
return s.get_lang_sys_tag (language_index);
}
hb_bool_t
hb_ot_layout_script_find_language (hb_ot_layout_t *layout,
hb_ot_layout_table_type_t table_type,
unsigned int script_index,
hb_tag_t language_tag,
unsigned int *language_index)
{
ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX);
const Script &s = get_gsubgpos_table (layout, table_type).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_LAYOUT_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_ot_layout_t *layout,
hb_ot_layout_table_type_t table_type,
unsigned int script_index,
unsigned int language_index,
unsigned int *feature_index)
{
const LangSys &l = get_gsubgpos_table (layout, table_type).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_count (hb_ot_layout_t *layout,
hb_ot_layout_table_type_t table_type,
unsigned int script_index,
unsigned int language_index)
{
const LangSys &l = get_gsubgpos_table (layout, table_type).get_script (script_index).get_lang_sys (language_index);
return l.get_feature_count ();
}
unsigned int
hb_ot_layout_language_get_feature_index (hb_ot_layout_t *layout,
hb_ot_layout_table_type_t table_type,
unsigned int script_index,
unsigned int language_index,
unsigned int num_feature)
{
const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
return l.get_feature_index (num_feature);
}
hb_tag_t
hb_ot_layout_language_get_feature_tag (hb_ot_layout_t *layout,
hb_ot_layout_table_type_t table_type,
unsigned int script_index,
unsigned int language_index,
unsigned int num_feature)
{
const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
unsigned int feature_index = l.get_feature_index (num_feature);
return g.get_feature_tag (feature_index);
}
hb_bool_t
hb_ot_layout_language_find_feature (hb_ot_layout_t *layout,
hb_ot_layout_table_type_t table_type,
unsigned int script_index,
unsigned int language_index,
hb_tag_t feature_tag,
unsigned int *feature_index)
{
ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX);
const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
unsigned int i;
for (i = 0; i < l.get_feature_count (); 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_count (hb_ot_layout_t *layout,
hb_ot_layout_table_type_t table_type,
unsigned int feature_index)
{
const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
const Feature &f = g.get_feature (feature_index);
return f.get_lookup_count ();
}
unsigned int
hb_ot_layout_feature_get_lookup_index (hb_ot_layout_t *layout,
hb_ot_layout_table_type_t table_type,
unsigned int feature_index,
unsigned int num_lookup)
{
const GSUBGPOS &g = get_gsubgpos_table (layout, table_type);
const Feature &f = g.get_feature (feature_index);
return f.get_lookup_index (num_lookup);
}
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/*
* GSUB
*/
hb_bool_t
hb_ot_layout_substitute_lookup (hb_ot_layout_t *layout,
hb_buffer_t *buffer,
unsigned int lookup_index,
hb_ot_layout_feature_mask_t mask)
{
const GSUB &gsub = *(layout->gsub);
const SubstLookup &l = gsub.get_lookup (lookup_index);
unsigned int lookup_type = l.get_type ();
unsigned int nesting_level_left = HB_OT_LAYOUT_MAX_NESTING_LEVEL;
unsigned int context_length = NO_CONTEXT;
bool handled, ret = false;
if (!l.is_reverse ()) {
/* in/out forward substitution */
_hb_buffer_clear_output (buffer);
buffer->in_pos = 0;
while (buffer->in_pos < buffer->in_length) {
if ((~IN_PROPERTIES (buffer->in_pos) & mask) &&
l.substitute (layout, buffer, context_length, nesting_level_left))
ret = true;
else
_hb_buffer_copy_output_glyph (buffer);
}
_hb_buffer_swap (buffer);
} else {
/* in-place backward substitution */
buffer->in_pos = buffer->in_length - 1;
do {
if ((~IN_PROPERTIES (buffer->in_pos) & mask) &&
l.substitute (layout, buffer, context_length, nesting_level_left))
ret = true;
else
buffer->in_pos--;
} while (buffer->in_pos);
}
return ret;
}