harfbuzz/src/hb-ot-map.cc

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/*
* Copyright (C) 2009,2010 Red Hat, Inc.
* Copyright (C) 2010 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-ot-map-private.hh"
#include "hb-ot-shape-private.hh"
HB_BEGIN_DECLS
void
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hb_ot_map_t::add_lookups (hb_face_t *face,
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unsigned int table_index,
unsigned int feature_index,
hb_mask_t mask)
{
unsigned int i = MAX_LOOKUPS - lookup_count[table_index];
lookup_map_t *lookups = lookup_maps[table_index] + lookup_count[table_index];
unsigned int *lookup_indices = (unsigned int *) lookups;
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hb_ot_layout_feature_get_lookup_indexes (face,
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table_tags[table_index],
feature_index,
0, &i,
lookup_indices);
lookup_count[table_index] += i;
while (i--) {
lookups[i].mask = mask;
lookups[i].index = lookup_indices[i];
}
}
void
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hb_ot_map_t::compile (hb_face_t *face,
hb_segment_properties_t *props)
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{
global_mask = 0;
lookup_count[0] = lookup_count[1] = 0;
if (!feature_count)
return;
/* Fetch script/language indices for GSUB/GPOS. We need these later to skip
* features not available in either table and not waste precious bits for them. */
const hb_tag_t *script_tags;
hb_tag_t language_tag;
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script_tags = hb_ot_tags_from_script (props->script);
language_tag = hb_ot_tag_from_language (props->language);
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unsigned int script_index[2], language_index[2];
for (unsigned int table_index = 0; table_index < 2; table_index++) {
hb_tag_t table_tag = table_tags[table_index];
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hb_ot_layout_table_choose_script (face, table_tag, script_tags, &script_index[table_index]);
hb_ot_layout_script_find_language (face, table_tag, script_index[table_index], language_tag, &language_index[table_index]);
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}
/* Sort features and merge duplicates */
qsort (feature_infos, feature_count, sizeof (feature_infos[0]), (hb_compare_func_t) feature_info_t::cmp);
unsigned int j = 0;
for (unsigned int i = 1; i < feature_count; i++)
if (feature_infos[i].tag != feature_infos[j].tag)
feature_infos[++j] = feature_infos[i];
else {
if (feature_infos[i].global)
feature_infos[j] = feature_infos[i];
else {
feature_infos[j].global = false;
feature_infos[j].value = MAX (feature_infos[j].value, feature_infos[i].value);
}
}
feature_count = j + 1;
/* Allocate bits now */
unsigned int next_bit = 1;
j = 0;
for (unsigned int i = 0; i < feature_count; i++) {
const feature_info_t *info = &feature_infos[i];
unsigned int bits_needed;
if (info->global && info->value == 1)
/* Uses the global bit */
bits_needed = 0;
else
bits_needed = _hb_bit_storage (info->value);
if (!info->value || next_bit + bits_needed > 8 * sizeof (hb_mask_t))
continue; /* Feature disabled, or not enough bits. */
bool found = false;
unsigned int feature_index[2];
for (unsigned int table_index = 0; table_index < 2; table_index++)
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found |= hb_ot_layout_language_find_feature (face,
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table_tags[table_index],
script_index[table_index],
language_index[table_index],
info->tag,
&feature_index[table_index]);
if (!found)
continue;
feature_map_t *map = &feature_maps[j++];
map->tag = info->tag;
map->index[0] = feature_index[0];
map->index[1] = feature_index[1];
if (info->global && info->value == 1) {
/* Uses the global bit */
map->shift = 0;
map->mask = 1;
} else {
map->shift = next_bit;
map->mask = (1 << (next_bit + bits_needed)) - (1 << next_bit);
next_bit += bits_needed;
if (info->global)
global_mask |= map->mask;
}
}
feature_count = j;
for (unsigned int table_index = 0; table_index < 2; table_index++) {
hb_tag_t table_tag = table_tags[table_index];
/* Collect lookup indices for features */
unsigned int required_feature_index;
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if (hb_ot_layout_language_get_required_feature_index (face,
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table_tag,
script_index[table_index],
language_index[table_index],
&required_feature_index))
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add_lookups (face, table_index, required_feature_index, 1);
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for (unsigned i = 0; i < feature_count; i++)
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add_lookups (face, table_index, feature_maps[i].index[table_index], feature_maps[i].mask);
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/* Sort lookups and merge duplicates */
qsort (lookup_maps[table_index], lookup_count[table_index], sizeof (lookup_maps[table_index][0]), (hb_compare_func_t) lookup_map_t::cmp);
if (lookup_count[table_index])
{
unsigned int j = 0;
for (unsigned int i = 1; i < lookup_count[table_index]; i++)
if (lookup_maps[table_index][i].index != lookup_maps[table_index][j].index)
lookup_maps[table_index][++j] = lookup_maps[table_index][i];
else
lookup_maps[table_index][j].mask |= lookup_maps[table_index][i].mask;
j++;
lookup_count[table_index] = j;
}
}
}
HB_END_DECLS