/*
* Copyright © 2009,2010 Red Hat, Inc.
* Copyright © 2010,2011,2013 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-ot-map-private.hh"
#include "hb-ot-layout-private.hh"
void
hb_ot_map_t::add_lookups (hb_face_t *face,
unsigned int table_index,
unsigned int feature_index,
hb_mask_t mask,
bool auto_zwj)
{
unsigned int lookup_indices[32];
unsigned int offset, len;
unsigned int table_lookup_count;
table_lookup_count = hb_ot_layout_table_get_lookup_count (face, table_tags[table_index]);
offset = 0;
do {
len = ARRAY_LENGTH (lookup_indices);
hb_ot_layout_feature_get_lookups (face,
table_tags[table_index],
feature_index,
offset, &len,
lookup_indices);
for (unsigned int i = 0; i < len; i++)
{
if (lookup_indices[i] >= table_lookup_count)
continue;
hb_ot_map_t::lookup_map_t *lookup = lookups[table_index].push ();
if (unlikely (!lookup))
return;
lookup->mask = mask;
lookup->index = lookup_indices[i];
lookup->auto_zwj = auto_zwj;
}
offset += len;
} while (len == ARRAY_LENGTH (lookup_indices));
}
hb_ot_map_builder_t::hb_ot_map_builder_t (hb_face_t *face_,
const hb_segment_properties_t *props_)
{
memset (this, 0, sizeof (*this));
face = face_;
props = *props_;
/* 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. */
hb_tag_t script_tags[3] = {HB_TAG_NONE, HB_TAG_NONE, HB_TAG_NONE};
hb_tag_t language_tag;
hb_ot_tags_from_script (props.script, &script_tags[0], &script_tags[1]);
language_tag = hb_ot_tag_from_language (props.language);
for (unsigned int table_index = 0; table_index < 2; table_index++) {
hb_tag_t table_tag = table_tags[table_index];
found_script[table_index] = (bool) hb_ot_layout_table_choose_script (face, table_tag, script_tags, &script_index[table_index], &chosen_script[table_index]);
hb_ot_layout_script_find_language (face, table_tag, script_index[table_index], language_tag, &language_index[table_index]);
}
}
void hb_ot_map_builder_t::add_feature (hb_tag_t tag, unsigned int value,
hb_ot_map_feature_flags_t flags)
{
feature_info_t *info = feature_infos.push();
if (unlikely (!info)) return;
if (unlikely (!tag)) return;
info->tag = tag;
info->seq = feature_infos.len;
info->max_value = value;
info->flags = flags;
info->default_value = (flags & F_GLOBAL) ? value : 0;
info->stage[0] = current_stage[0];
info->stage[1] = current_stage[1];
}
void hb_ot_map_t::collect_lookups (unsigned int table_index, hb_set_t *lookups_out) const
{
for (unsigned int i = 0; i < lookups[table_index].len; i++)
hb_set_add (lookups_out, lookups[table_index][i].index);
}
void hb_ot_map_builder_t::add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func)
{
stage_info_t *s = stages[table_index].push ();
if (likely (s)) {
s->index = current_stage[table_index];
s->pause_func = pause_func;
}
current_stage[table_index]++;
}
void
hb_ot_map_builder_t::compile (hb_ot_map_t &m)
{
m.global_mask = 1;
unsigned int required_feature_index[2];
hb_tag_t required_feature_tag[2];
/* We default to applying required feature in stage 0. If the required
* feature has a tag that is known to the shaper, we apply required feature
* in the stage for that tag.
*/
unsigned int required_feature_stage[2] = {0, 0};
for (unsigned int table_index = 0; table_index < 2; table_index++)
{
m.chosen_script[table_index] = chosen_script[table_index];
m.found_script[table_index] = found_script[table_index];
hb_ot_layout_language_get_required_feature (face,
table_tags[table_index],
script_index[table_index],
language_index[table_index],
&required_feature_index[table_index],
&required_feature_tag[table_index]);
}
if (!feature_infos.len)
return;
/* Sort features and merge duplicates */
{
feature_infos.qsort ();
unsigned int j = 0;
for (unsigned int i = 1; i < feature_infos.len; i++)
if (feature_infos[i].tag != feature_infos[j].tag)
feature_infos[++j] = feature_infos[i];
else {
if (feature_infos[i].flags & F_GLOBAL) {
feature_infos[j].flags |= F_GLOBAL;
feature_infos[j].max_value = feature_infos[i].max_value;
feature_infos[j].default_value = feature_infos[i].default_value;
} else {
feature_infos[j].flags &= ~F_GLOBAL;
feature_infos[j].max_value = MAX (feature_infos[j].max_value, feature_infos[i].max_value);
/* Inherit default_value from j */
}
feature_infos[j].flags |= (feature_infos[i].flags & F_HAS_FALLBACK);
feature_infos[j].stage[0] = MIN (feature_infos[j].stage[0], feature_infos[i].stage[0]);
feature_infos[j].stage[1] = MIN (feature_infos[j].stage[1], feature_infos[i].stage[1]);
}
feature_infos.shrink (j + 1);
}
/* Allocate bits now */
unsigned int next_bit = 1;
for (unsigned int i = 0; i < feature_infos.len; i++)
{
const feature_info_t *info = &feature_infos[i];
unsigned int bits_needed;
if ((info->flags & F_GLOBAL) && info->max_value == 1)
/* Uses the global bit */
bits_needed = 0;
else
bits_needed = _hb_bit_storage (info->max_value);
if (!info->max_value || next_bit + bits_needed > 8 * sizeof (hb_mask_t))
continue; /* Feature disabled, or not enough bits. */
hb_bool_t found = false;
unsigned int feature_index[2];
for (unsigned int table_index = 0; table_index < 2; table_index++)
{
if (required_feature_tag[table_index] == info->tag)
required_feature_stage[table_index] = info->stage[table_index];
found |= hb_ot_layout_language_find_feature (face,
table_tags[table_index],
script_index[table_index],
language_index[table_index],
info->tag,
&feature_index[table_index]);
}
if (!found && (info->flags & F_GLOBAL_SEARCH))
{
for (unsigned int table_index = 0; table_index < 2; table_index++)
{
found |= hb_ot_layout_table_find_feature (face,
table_tags[table_index],
info->tag,
&feature_index[table_index]);
}
}
if (!found && !(info->flags & F_HAS_FALLBACK))
continue;
hb_ot_map_t::feature_map_t *map = m.features.push ();
if (unlikely (!map))
break;
map->tag = info->tag;
map->index[0] = feature_index[0];
map->index[1] = feature_index[1];
map->stage[0] = info->stage[0];
map->stage[1] = info->stage[1];
map->auto_zwj = !(info->flags & F_MANUAL_ZWJ);
if ((info->flags & F_GLOBAL) && info->max_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;
m.global_mask |= (info->default_value << map->shift) & map->mask;
}
map->_1_mask = (1 << map->shift) & map->mask;
map->needs_fallback = !found;
}
feature_infos.shrink (0); /* Done with these */
add_gsub_pause (NULL);
add_gpos_pause (NULL);
for (unsigned int table_index = 0; table_index < 2; table_index++)
{
/* Collect lookup indices for features */
unsigned int stage_index = 0;
unsigned int last_num_lookups = 0;
for (unsigned stage = 0; stage < current_stage[table_index]; stage++)
{
if (required_feature_index[table_index] != HB_OT_LAYOUT_NO_FEATURE_INDEX &&
required_feature_stage[table_index] == stage)
m.add_lookups (face, table_index,
required_feature_index[table_index],
1 /* mask */,
true /* auto_zwj */);
for (unsigned i = 0; i < m.features.len; i++)
if (m.features[i].stage[table_index] == stage)
m.add_lookups (face, table_index,
m.features[i].index[table_index],
m.features[i].mask,
m.features[i].auto_zwj);
/* Sort lookups and merge duplicates */
if (last_num_lookups < m.lookups[table_index].len)
{
m.lookups[table_index].qsort (last_num_lookups, m.lookups[table_index].len);
unsigned int j = last_num_lookups;
for (unsigned int i = j + 1; i < m.lookups[table_index].len; i++)
if (m.lookups[table_index][i].index != m.lookups[table_index][j].index)
m.lookups[table_index][++j] = m.lookups[table_index][i];
else
{
m.lookups[table_index][j].mask |= m.lookups[table_index][i].mask;
m.lookups[table_index][j].auto_zwj &= m.lookups[table_index][i].auto_zwj;
}
m.lookups[table_index].shrink (j + 1);
}
last_num_lookups = m.lookups[table_index].len;
if (stage_index < stages[table_index].len && stages[table_index][stage_index].index == stage) {
hb_ot_map_t::stage_map_t *stage_map = m.stages[table_index].push ();
if (likely (stage_map)) {
stage_map->last_lookup = last_num_lookups;
stage_map->pause_func = stages[table_index][stage_index].pause_func;
}
stage_index++;
}
}
}
}