1 /* 2 * Copyright 2009,2010 Red Hat, Inc. 3 * Copyright 2010,2011,2013 Google, Inc. 4 * 5 * This is part of HarfBuzz, a text shaping library. 6 * 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. 12 * 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 17 * DAMAGE. 18 * 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. 24 * 25 * Red Hat Author(s): Behdad Esfahbod 26 * Google Author(s): Behdad Esfahbod 27 */ 28 29 #include "hb-ot-map-private.hh" 30 31 #include "hb-ot-layout-private.hh" 32 33 34 void 35 hb_ot_map_t::add_lookups (hb_face_t *face, 36 unsigned int table_index, 37 unsigned int feature_index, 38 hb_mask_t mask, 39 bool auto_zwj) 40 { 41 unsigned int lookup_indices[32]; 42 unsigned int offset, len; 43 unsigned int table_lookup_count; 44 45 table_lookup_count = hb_ot_layout_table_get_lookup_count (face, table_tags[table_index]); 46 47 offset = 0; 48 do { 49 len = ARRAY_LENGTH (lookup_indices); 50 hb_ot_layout_feature_get_lookups (face, 51 table_tags[table_index], 52 feature_index, 53 offset, &len, 54 lookup_indices); 55 56 for (unsigned int i = 0; i < len; i++) 57 { 58 if (lookup_indices[i] >= table_lookup_count) 59 continue; 60 hb_ot_map_t::lookup_map_t *lookup = lookups[table_index].push (); 61 if (unlikely (!lookup)) 62 return; 63 lookup->mask = mask; 64 lookup->index = lookup_indices[i]; 65 lookup->auto_zwj = auto_zwj; 66 } 67 68 offset += len; 69 } while (len == ARRAY_LENGTH (lookup_indices)); 70 } 71 72 hb_ot_map_builder_t::hb_ot_map_builder_t (hb_face_t *face_, 73 const hb_segment_properties_t *props_) 74 { 75 memset (this, 0, sizeof (*this)); 76 77 face = face_; 78 props = *props_; 79 80 81 /* Fetch script/language indices for GSUB/GPOS. We need these later to skip 82 * features not available in either table and not waste precious bits for them. */ 83 84 hb_tag_t script_tags[3] = {HB_TAG_NONE, HB_TAG_NONE, HB_TAG_NONE}; 85 hb_tag_t language_tag; 86 87 hb_ot_tags_from_script (props.script, &script_tags[0], &script_tags[1]); 88 language_tag = hb_ot_tag_from_language (props.language); 89 90 for (unsigned int table_index = 0; table_index < 2; table_index++) { 91 hb_tag_t table_tag = table_tags[table_index]; 92 found_script[table_index] = (bool) hb_ot_layout_table_choose_script (face, table_tag, script_tags, &script_index[table_index], &chosen_script[table_index]); 93 hb_ot_layout_script_find_language (face, table_tag, script_index[table_index], language_tag, &language_index[table_index]); 94 } 95 } 96 97 void hb_ot_map_builder_t::add_feature (hb_tag_t tag, unsigned int value, 98 hb_ot_map_feature_flags_t flags) 99 { 100 feature_info_t *info = feature_infos.push(); 101 if (unlikely (!info)) return; 102 if (unlikely (!tag)) return; 103 info->tag = tag; 104 info->seq = feature_infos.len; 105 info->max_value = value; 106 info->flags = flags; 107 info->default_value = (flags & F_GLOBAL) ? value : 0; 108 info->stage[0] = current_stage[0]; 109 info->stage[1] = current_stage[1]; 110 } 111 112 113 void hb_ot_map_t::collect_lookups (unsigned int table_index, hb_set_t *lookups_out) const 114 { 115 for (unsigned int i = 0; i < lookups[table_index].len; i++) 116 hb_set_add (lookups_out, lookups[table_index][i].index); 117 } 118 119 void hb_ot_map_builder_t::add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func) 120 { 121 stage_info_t *s = stages[table_index].push (); 122 if (likely (s)) { 123 s->index = current_stage[table_index]; 124 s->pause_func = pause_func; 125 } 126 127 current_stage[table_index]++; 128 } 129 130 void 131 hb_ot_map_builder_t::compile (hb_ot_map_t &m) 132 { 133 m.global_mask = 1; 134 135 unsigned int required_feature_index[2]; 136 hb_tag_t required_feature_tag[2]; 137 /* We default to applying required feature in stage 0. If the required 138 * feature has a tag that is known to the shaper, we apply required feature 139 * in the stage for that tag. 140 */ 141 unsigned int required_feature_stage[2] = {0, 0}; 142 143 for (unsigned int table_index = 0; table_index < 2; table_index++) 144 { 145 m.chosen_script[table_index] = chosen_script[table_index]; 146 m.found_script[table_index] = found_script[table_index]; 147 148 hb_ot_layout_language_get_required_feature (face, 149 table_tags[table_index], 150 script_index[table_index], 151 language_index[table_index], 152 &required_feature_index[table_index], 153 &required_feature_tag[table_index]); 154 } 155 156 if (!feature_infos.len) 157 return; 158 159 /* Sort features and merge duplicates */ 160 { 161 feature_infos.qsort (); 162 unsigned int j = 0; 163 for (unsigned int i = 1; i < feature_infos.len; i++) 164 if (feature_infos[i].tag != feature_infos[j].tag) 165 feature_infos[++j] = feature_infos[i]; 166 else { 167 if (feature_infos[i].flags & F_GLOBAL) { 168 feature_infos[j].flags |= F_GLOBAL; 169 feature_infos[j].max_value = feature_infos[i].max_value; 170 feature_infos[j].default_value = feature_infos[i].default_value; 171 } else { 172 feature_infos[j].flags &= ~F_GLOBAL; 173 feature_infos[j].max_value = MAX (feature_infos[j].max_value, feature_infos[i].max_value); 174 /* Inherit default_value from j */ 175 } 176 feature_infos[j].flags |= (feature_infos[i].flags & F_HAS_FALLBACK); 177 feature_infos[j].stage[0] = MIN (feature_infos[j].stage[0], feature_infos[i].stage[0]); 178 feature_infos[j].stage[1] = MIN (feature_infos[j].stage[1], feature_infos[i].stage[1]); 179 } 180 feature_infos.shrink (j + 1); 181 } 182 183 184 /* Allocate bits now */ 185 unsigned int next_bit = 1; 186 for (unsigned int i = 0; i < feature_infos.len; i++) 187 { 188 const feature_info_t *info = &feature_infos[i]; 189 190 unsigned int bits_needed; 191 192 if ((info->flags & F_GLOBAL) && info->max_value == 1) 193 /* Uses the global bit */ 194 bits_needed = 0; 195 else 196 bits_needed = _hb_bit_storage (info->max_value); 197 198 if (!info->max_value || next_bit + bits_needed > 8 * sizeof (hb_mask_t)) 199 continue; /* Feature disabled, or not enough bits. */ 200 201 202 hb_bool_t found = false; 203 unsigned int feature_index[2]; 204 for (unsigned int table_index = 0; table_index < 2; table_index++) 205 { 206 if (required_feature_tag[table_index] == info->tag) 207 required_feature_stage[table_index] = info->stage[table_index]; 208 209 found |= hb_ot_layout_language_find_feature (face, 210 table_tags[table_index], 211 script_index[table_index], 212 language_index[table_index], 213 info->tag, 214 &feature_index[table_index]); 215 } 216 if (!found && (info->flags & F_GLOBAL_SEARCH)) 217 { 218 for (unsigned int table_index = 0; table_index < 2; table_index++) 219 { 220 found |= hb_ot_layout_table_find_feature (face, 221 table_tags[table_index], 222 info->tag, 223 &feature_index[table_index]); 224 } 225 } 226 if (!found && !(info->flags & F_HAS_FALLBACK)) 227 continue; 228 229 230 hb_ot_map_t::feature_map_t *map = m.features.push (); 231 if (unlikely (!map)) 232 break; 233 234 map->tag = info->tag; 235 map->index[0] = feature_index[0]; 236 map->index[1] = feature_index[1]; 237 map->stage[0] = info->stage[0]; 238 map->stage[1] = info->stage[1]; 239 map->auto_zwj = !(info->flags & F_MANUAL_ZWJ); 240 if ((info->flags & F_GLOBAL) && info->max_value == 1) { 241 /* Uses the global bit */ 242 map->shift = 0; 243 map->mask = 1; 244 } else { 245 map->shift = next_bit; 246 map->mask = (1 << (next_bit + bits_needed)) - (1 << next_bit); 247 next_bit += bits_needed; 248 m.global_mask |= (info->default_value << map->shift) & map->mask; 249 } 250 map->_1_mask = (1 << map->shift) & map->mask; 251 map->needs_fallback = !found; 252 253 } 254 feature_infos.shrink (0); /* Done with these */ 255 256 257 add_gsub_pause (NULL); 258 add_gpos_pause (NULL); 259 260 for (unsigned int table_index = 0; table_index < 2; table_index++) 261 { 262 /* Collect lookup indices for features */ 263 264 unsigned int stage_index = 0; 265 unsigned int last_num_lookups = 0; 266 for (unsigned stage = 0; stage < current_stage[table_index]; stage++) 267 { 268 if (required_feature_index[table_index] != HB_OT_LAYOUT_NO_FEATURE_INDEX && 269 required_feature_stage[table_index] == stage) 270 m.add_lookups (face, table_index, 271 required_feature_index[table_index], 272 1 /* mask */, 273 true /* auto_zwj */); 274 275 for (unsigned i = 0; i < m.features.len; i++) 276 if (m.features[i].stage[table_index] == stage) 277 m.add_lookups (face, table_index, 278 m.features[i].index[table_index], 279 m.features[i].mask, 280 m.features[i].auto_zwj); 281 282 /* Sort lookups and merge duplicates */ 283 if (last_num_lookups < m.lookups[table_index].len) 284 { 285 m.lookups[table_index].qsort (last_num_lookups, m.lookups[table_index].len); 286 287 unsigned int j = last_num_lookups; 288 for (unsigned int i = j + 1; i < m.lookups[table_index].len; i++) 289 if (m.lookups[table_index][i].index != m.lookups[table_index][j].index) 290 m.lookups[table_index][++j] = m.lookups[table_index][i]; 291 else 292 { 293 m.lookups[table_index][j].mask |= m.lookups[table_index][i].mask; 294 m.lookups[table_index][j].auto_zwj &= m.lookups[table_index][i].auto_zwj; 295 } 296 m.lookups[table_index].shrink (j + 1); 297 } 298 299 last_num_lookups = m.lookups[table_index].len; 300 301 if (stage_index < stages[table_index].len && stages[table_index][stage_index].index == stage) { 302 hb_ot_map_t::stage_map_t *stage_map = m.stages[table_index].push (); 303 if (likely (stage_map)) { 304 stage_map->last_lookup = last_num_lookups; 305 stage_map->pause_func = stages[table_index][stage_index].pause_func; 306 } 307 308 stage_index++; 309 } 310 } 311 } 312 } 313
