2 * Copyright © 2009,2010 Red Hat, Inc.
3 * Copyright © 2010 Google, Inc.
5 * This is part of HarfBuzz, a text shaping library.
7 * Permission is hereby granted, without written agreement and without
8 * license or royalty fees, to use, copy, modify, and distribute this
9 * software and its documentation for any purpose, provided that the
10 * above copyright notice and the following two paragraphs appear in
11 * all copies of this software.
13 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
14 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
15 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
16 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
19 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
20 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
22 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
23 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
25 * Red Hat Author(s): Behdad Esfahbod
26 * Google Author(s): Behdad Esfahbod
29 #include "hb-ot-map-private.hh"
31 #include "hb-ot-shape-private.hh"
37 hb_ot_map_t::add_lookups (hb_face_t *face,
38 unsigned int table_index,
39 unsigned int feature_index,
42 unsigned int lookup_indices[32];
43 unsigned int offset, len;
47 len = ARRAY_LENGTH (lookup_indices);
48 hb_ot_layout_feature_get_lookup_indexes (face,
49 table_tags[table_index],
54 for (unsigned int i = 0; i < len; i++) {
55 hb_ot_map_t::lookup_map_t *lookup = lookups[table_index].push ();
56 if (unlikely (!lookup))
59 lookup->index = lookup_indices[i];
63 } while (len == ARRAY_LENGTH (lookup_indices));
68 hb_ot_map_builder_t::compile (hb_face_t *face,
69 const hb_segment_properties_t *props,
74 if (!feature_infos.len)
78 /* Fetch script/language indices for GSUB/GPOS. We need these later to skip
79 * features not available in either table and not waste precious bits for them. */
81 hb_tag_t script_tags[3] = {HB_TAG_NONE};
82 hb_tag_t language_tag;
84 hb_ot_tags_from_script (props->script, &script_tags[0], &script_tags[1]);
85 language_tag = hb_ot_tag_from_language (props->language);
87 unsigned int script_index[2], language_index[2];
88 for (unsigned int table_index = 0; table_index < 2; table_index++) {
89 hb_tag_t table_tag = table_tags[table_index];
90 hb_ot_layout_table_choose_script (face, table_tag, script_tags, &script_index[table_index]);
91 hb_ot_layout_script_find_language (face, table_tag, script_index[table_index], language_tag, &language_index[table_index]);
95 /* Sort features and merge duplicates */
96 feature_infos.sort ();
98 for (unsigned int i = 1; i < feature_infos.len; i++)
99 if (feature_infos[i].tag != feature_infos[j].tag)
100 feature_infos[++j] = feature_infos[i];
102 if (feature_infos[i].global)
103 feature_infos[j] = feature_infos[i];
105 feature_infos[j].global = false;
106 feature_infos[j].max_value = MAX (feature_infos[j].max_value, feature_infos[i].max_value);
107 /* Inherit default_value from j */
110 feature_infos.shrink (j + 1);
113 /* Allocate bits now */
114 unsigned int next_bit = 1;
115 for (unsigned int i = 0; i < feature_infos.len; i++) {
116 const feature_info_t *info = &feature_infos[i];
118 unsigned int bits_needed;
120 if (info->global && info->max_value == 1)
121 /* Uses the global bit */
124 bits_needed = _hb_bit_storage (info->max_value);
126 if (!info->max_value || next_bit + bits_needed > 8 * sizeof (hb_mask_t))
127 continue; /* Feature disabled, or not enough bits. */
131 unsigned int feature_index[2];
132 for (unsigned int table_index = 0; table_index < 2; table_index++)
133 found |= hb_ot_layout_language_find_feature (face,
134 table_tags[table_index],
135 script_index[table_index],
136 language_index[table_index],
138 &feature_index[table_index]);
143 hb_ot_map_t::feature_map_t *map = m.features.push ();
147 map->tag = info->tag;
148 map->index[0] = feature_index[0];
149 map->index[1] = feature_index[1];
150 if (info->global && info->max_value == 1) {
151 /* Uses the global bit */
155 map->shift = next_bit;
156 map->mask = (1 << (next_bit + bits_needed)) - (1 << next_bit);
157 next_bit += bits_needed;
159 m.global_mask |= (info->default_value << map->shift) & map->mask;
161 map->_1_mask = (1 << map->shift) & map->mask;
164 feature_infos.shrink (0); /* Done with these */
167 for (unsigned int table_index = 0; table_index < 2; table_index++) {
168 hb_tag_t table_tag = table_tags[table_index];
170 /* Collect lookup indices for features */
172 unsigned int required_feature_index;
173 if (hb_ot_layout_language_get_required_feature_index (face,
175 script_index[table_index],
176 language_index[table_index],
177 &required_feature_index))
178 m.add_lookups (face, table_index, required_feature_index, 1);
180 for (unsigned i = 0; i < m.features.len; i++)
181 m.add_lookups (face, table_index, m.features[i].index[table_index], m.features[i].mask);
183 /* Sort lookups and merge duplicates */
184 m.lookups[table_index].sort ();
185 if (m.lookups[table_index].len)
188 for (unsigned int i = 1; i < m.lookups[table_index].len; i++)
189 if (m.lookups[table_index][i].index != m.lookups[table_index][j].index)
190 m.lookups[table_index][++j] = m.lookups[table_index][i];
192 m.lookups[table_index][j].mask |= m.lookups[table_index][i].mask;
193 m.lookups[table_index].shrink (j + 1);