hb-ot-map.cc revision 6fddf2d7397411bba8a23ac535e8b851495d3105
1/* 2 * Copyright © 2009,2010 Red Hat, Inc. 3 * Copyright © 2010,2011 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 32void 33hb_ot_map_t::add_lookups (hb_face_t *face, 34 unsigned int table_index, 35 unsigned int feature_index, 36 hb_mask_t mask) 37{ 38 unsigned int lookup_indices[32]; 39 unsigned int offset, len; 40 41 offset = 0; 42 do { 43 len = ARRAY_LENGTH (lookup_indices); 44 hb_ot_layout_feature_get_lookup_indexes (face, 45 table_tags[table_index], 46 feature_index, 47 offset, &len, 48 lookup_indices); 49 50 for (unsigned int i = 0; i < len; i++) { 51 hb_ot_map_t::lookup_map_t *lookup = lookups[table_index].push (); 52 if (unlikely (!lookup)) 53 return; 54 lookup->mask = mask; 55 lookup->index = lookup_indices[i]; 56 } 57 58 offset += len; 59 } while (len == ARRAY_LENGTH (lookup_indices)); 60} 61 62hb_ot_map_builder_t::hb_ot_map_builder_t (hb_face_t *face_, 63 const hb_segment_properties_t *props_) 64{ 65 memset (this, 0, sizeof (*this)); 66 67 face = face_; 68 props = *props_; 69 70 71 /* Fetch script/language indices for GSUB/GPOS. We need these later to skip 72 * features not available in either table and not waste precious bits for them. */ 73 74 hb_tag_t script_tags[3] = {HB_TAG_NONE, HB_TAG_NONE, HB_TAG_NONE}; 75 hb_tag_t language_tag; 76 77 hb_ot_tags_from_script (props.script, &script_tags[0], &script_tags[1]); 78 language_tag = hb_ot_tag_from_language (props.language); 79 80 for (unsigned int table_index = 0; table_index < 2; table_index++) { 81 hb_tag_t table_tag = table_tags[table_index]; 82 hb_ot_layout_table_choose_script (face, table_tag, script_tags, &script_index[table_index], &chosen_script[table_index]); 83 hb_ot_layout_script_find_language (face, table_tag, script_index[table_index], language_tag, &language_index[table_index]); 84 } 85} 86 87void hb_ot_map_builder_t::add_feature (hb_tag_t tag, unsigned int value, bool global, bool has_fallback) 88{ 89 feature_info_t *info = feature_infos.push(); 90 if (unlikely (!info)) return; 91 info->tag = tag; 92 info->seq = feature_infos.len; 93 info->max_value = value; 94 info->global = global; 95 info->has_fallback = has_fallback; 96 info->default_value = global ? value : 0; 97 info->stage[0] = current_stage[0]; 98 info->stage[1] = current_stage[1]; 99} 100 101/* Keep the next two functions in sync. */ 102 103void hb_ot_map_t::substitute (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const 104{ 105 const unsigned int table_index = 0; 106 unsigned int i = 0; 107 108 for (unsigned int pause_index = 0; pause_index < pauses[table_index].len; pause_index++) { 109 const pause_map_t *pause = &pauses[table_index][pause_index]; 110 for (; i < pause->num_lookups; i++) 111 hb_ot_layout_substitute_lookup (font, buffer, lookups[table_index][i].index, lookups[table_index][i].mask); 112 113 buffer->clear_output (); 114 115 if (pause->callback) 116 pause->callback (plan, font, buffer); 117 } 118 119 for (; i < lookups[table_index].len; i++) 120 hb_ot_layout_substitute_lookup (font, buffer, lookups[table_index][i].index, lookups[table_index][i].mask); 121} 122 123void hb_ot_map_t::position (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const 124{ 125 const unsigned int table_index = 1; 126 unsigned int i = 0; 127 128 for (unsigned int pause_index = 0; pause_index < pauses[table_index].len; pause_index++) { 129 const pause_map_t *pause = &pauses[table_index][pause_index]; 130 for (; i < pause->num_lookups; i++) 131 hb_ot_layout_position_lookup (font, buffer, lookups[table_index][i].index, lookups[table_index][i].mask); 132 133 if (pause->callback) 134 pause->callback (plan, font, buffer); 135 } 136 137 for (; i < lookups[table_index].len; i++) 138 hb_ot_layout_position_lookup (font, buffer, lookups[table_index][i].index, lookups[table_index][i].mask); 139} 140 141void hb_ot_map_t::substitute_closure (const hb_ot_shape_plan_t *plan, hb_face_t *face, hb_set_t *glyphs) const 142{ 143 unsigned int table_index = 0; 144 for (unsigned int i = 0; i < lookups[table_index].len; i++) 145 hb_ot_layout_substitute_closure_lookup (face, lookups[table_index][i].index, glyphs); 146} 147 148void hb_ot_map_builder_t::add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func) 149{ 150 pause_info_t *p = pauses[table_index].push (); 151 if (likely (p)) { 152 p->stage = current_stage[table_index]; 153 p->callback = pause_func; 154 } 155 156 current_stage[table_index]++; 157} 158 159void 160hb_ot_map_builder_t::compile (hb_ot_map_t &m) 161{ 162 m.global_mask = 1; 163 164 for (unsigned int table_index = 0; table_index < 2; table_index++) 165 m.chosen_script[table_index] = chosen_script[table_index]; 166 167 if (!feature_infos.len) 168 return; 169 170 /* Sort features and merge duplicates */ 171 { 172 feature_infos.sort (); 173 unsigned int j = 0; 174 for (unsigned int i = 1; i < feature_infos.len; i++) 175 if (feature_infos[i].tag != feature_infos[j].tag) 176 feature_infos[++j] = feature_infos[i]; 177 else { 178 if (feature_infos[i].global) { 179 feature_infos[j].global = true; 180 feature_infos[j].max_value = feature_infos[i].max_value; 181 feature_infos[j].default_value = feature_infos[i].default_value; 182 } else { 183 feature_infos[j].global = false; 184 feature_infos[j].max_value = MAX (feature_infos[j].max_value, feature_infos[i].max_value); 185 } 186 feature_infos[j].has_fallback = feature_infos[j].has_fallback || feature_infos[i].has_fallback; 187 feature_infos[j].stage[0] = MIN (feature_infos[j].stage[0], feature_infos[i].stage[0]); 188 feature_infos[j].stage[1] = MIN (feature_infos[j].stage[1], feature_infos[i].stage[1]); 189 /* Inherit default_value from j */ 190 } 191 feature_infos.shrink (j + 1); 192 } 193 194 195 /* Allocate bits now */ 196 unsigned int next_bit = 1; 197 for (unsigned int i = 0; i < feature_infos.len; i++) { 198 const feature_info_t *info = &feature_infos[i]; 199 200 unsigned int bits_needed; 201 202 if (info->global && info->max_value == 1) 203 /* Uses the global bit */ 204 bits_needed = 0; 205 else 206 bits_needed = _hb_bit_storage (info->max_value); 207 208 if (!info->max_value || next_bit + bits_needed > 8 * sizeof (hb_mask_t)) 209 continue; /* Feature disabled, or not enough bits. */ 210 211 212 bool found = false; 213 unsigned int feature_index[2]; 214 for (unsigned int table_index = 0; table_index < 2; table_index++) 215 found |= hb_ot_layout_language_find_feature (face, 216 table_tags[table_index], 217 script_index[table_index], 218 language_index[table_index], 219 info->tag, 220 &feature_index[table_index]); 221 if (!found && !info->has_fallback) 222 continue; 223 224 225 hb_ot_map_t::feature_map_t *map = m.features.push (); 226 if (unlikely (!map)) 227 break; 228 229 map->tag = info->tag; 230 map->index[0] = feature_index[0]; 231 map->index[1] = feature_index[1]; 232 map->stage[0] = info->stage[0]; 233 map->stage[1] = info->stage[1]; 234 if (info->global && info->max_value == 1) { 235 /* Uses the global bit */ 236 map->shift = 0; 237 map->mask = 1; 238 } else { 239 map->shift = next_bit; 240 map->mask = (1 << (next_bit + bits_needed)) - (1 << next_bit); 241 next_bit += bits_needed; 242 if (info->global) 243 m.global_mask |= (info->default_value << map->shift) & map->mask; 244 } 245 map->_1_mask = (1 << map->shift) & map->mask; 246 map->needs_fallback = !found; 247 248 } 249 feature_infos.shrink (0); /* Done with these */ 250 251 252 add_gsub_pause (NULL); 253 add_gpos_pause (NULL); 254 255 for (unsigned int table_index = 0; table_index < 2; table_index++) { 256 hb_tag_t table_tag = table_tags[table_index]; 257 258 /* Collect lookup indices for features */ 259 260 unsigned int required_feature_index; 261 if (hb_ot_layout_language_get_required_feature_index (face, 262 table_tag, 263 script_index[table_index], 264 language_index[table_index], 265 &required_feature_index)) 266 m.add_lookups (face, table_index, required_feature_index, 1); 267 268 unsigned int pause_index = 0; 269 unsigned int last_num_lookups = 0; 270 for (unsigned stage = 0; stage < current_stage[table_index]; stage++) 271 { 272 for (unsigned i = 0; i < m.features.len; i++) 273 if (m.features[i].stage[table_index] == stage) 274 m.add_lookups (face, table_index, m.features[i].index[table_index], m.features[i].mask); 275 276 /* Sort lookups and merge duplicates */ 277 if (last_num_lookups < m.lookups[table_index].len) 278 { 279 m.lookups[table_index].sort (last_num_lookups, m.lookups[table_index].len); 280 281 unsigned int j = last_num_lookups; 282 for (unsigned int i = j + 1; i < m.lookups[table_index].len; i++) 283 if (m.lookups[table_index][i].index != m.lookups[table_index][j].index) 284 m.lookups[table_index][++j] = m.lookups[table_index][i]; 285 else 286 m.lookups[table_index][j].mask |= m.lookups[table_index][i].mask; 287 m.lookups[table_index].shrink (j + 1); 288 } 289 290 last_num_lookups = m.lookups[table_index].len; 291 292 if (pause_index < pauses[table_index].len && pauses[table_index][pause_index].stage == stage) { 293 hb_ot_map_t::pause_map_t *pause_map = m.pauses[table_index].push (); 294 if (likely (pause_map)) { 295 pause_map->num_lookups = last_num_lookups; 296 pause_map->callback = pauses[table_index][pause_index].callback; 297 } 298 299 pause_index++; 300 } 301 } 302 } 303} 304