1 /* 2 * Copyright 2011,2012,2013 Google, Inc. 3 * 4 * This is part of HarfBuzz, a text shaping library. 5 * 6 * Permission is hereby granted, without written agreement and without 7 * license or royalty fees, to use, copy, modify, and distribute this 8 * software and its documentation for any purpose, provided that the 9 * above copyright notice and the following two paragraphs appear in 10 * all copies of this software. 11 * 12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR 13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES 14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN 15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH 16 * DAMAGE. 17 * 18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, 19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS 21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO 22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. 23 * 24 * Google Author(s): Behdad Esfahbod 25 */ 26 27 #include "hb-ot-shape-complex-indic-private.hh" 28 29 /* buffer var allocations */ 30 #define sea_category() complex_var_u8_0() /* indic_category_t */ 31 #define sea_position() complex_var_u8_1() /* indic_position_t */ 32 33 34 /* 35 * South-East Asian shaper. 36 * Loosely based on the Myanmar spec / shaper. 37 * There is no OpenType spec for this. 38 */ 39 40 static const hb_tag_t 41 basic_features[] = 42 { 43 /* 44 * Basic features. 45 * These features are applied in order, one at a time, after initial_reordering. 46 */ 47 HB_TAG('p','r','e','f'), 48 HB_TAG('a','b','v','f'), 49 HB_TAG('b','l','w','f'), 50 HB_TAG('p','s','t','f'), 51 }; 52 static const hb_tag_t 53 other_features[] = 54 { 55 /* 56 * Other features. 57 * These features are applied all at once, after final_reordering. 58 */ 59 HB_TAG('p','r','e','s'), 60 HB_TAG('a','b','v','s'), 61 HB_TAG('b','l','w','s'), 62 HB_TAG('p','s','t','s'), 63 /* Positioning features, though we don't care about the types. */ 64 HB_TAG('d','i','s','t'), 65 }; 66 67 static void 68 setup_syllables (const hb_ot_shape_plan_t *plan, 69 hb_font_t *font, 70 hb_buffer_t *buffer); 71 static void 72 initial_reordering (const hb_ot_shape_plan_t *plan, 73 hb_font_t *font, 74 hb_buffer_t *buffer); 75 static void 76 final_reordering (const hb_ot_shape_plan_t *plan, 77 hb_font_t *font, 78 hb_buffer_t *buffer); 79 80 static void 81 collect_features_sea (hb_ot_shape_planner_t *plan) 82 { 83 hb_ot_map_builder_t *map = &plan->map; 84 85 /* Do this before any lookups have been applied. */ 86 map->add_gsub_pause (setup_syllables); 87 88 map->add_global_bool_feature (HB_TAG('l','o','c','l')); 89 /* The Indic specs do not require ccmp, but we apply it here since if 90 * there is a use of it, it's typically at the beginning. */ 91 map->add_global_bool_feature (HB_TAG('c','c','m','p')); 92 93 map->add_gsub_pause (initial_reordering); 94 for (unsigned int i = 0; i < ARRAY_LENGTH (basic_features); i++) 95 { 96 map->add_feature (basic_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ); 97 map->add_gsub_pause (NULL); 98 } 99 map->add_gsub_pause (final_reordering); 100 for (unsigned int i = 0; i < ARRAY_LENGTH (other_features); i++) 101 map->add_feature (other_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ); 102 } 103 104 static void 105 override_features_sea (hb_ot_shape_planner_t *plan) 106 { 107 plan->map.add_feature (HB_TAG('l','i','g','a'), 0, F_GLOBAL); 108 } 109 110 111 enum syllable_type_t { 112 consonant_syllable, 113 broken_cluster, 114 non_sea_cluster, 115 }; 116 117 #include "hb-ot-shape-complex-sea-machine.hh" 118 119 120 /* Note: This enum is duplicated in the -machine.rl source file. 121 * Not sure how to avoid duplication. */ 122 enum sea_category_t { 123 // OT_C = 1, 124 OT_GB = 12, /* Generic Base XXX DOTTED CIRCLE only for now */ 125 // OT_H = 4, /* Halant */ 126 OT_IV = 2, /* Independent Vowel */ 127 OT_MR = 22, /* Medial Ra */ 128 // OT_CM = 17, /* Consonant Medial */ 129 OT_VAbv = 26, 130 OT_VBlw = 27, 131 OT_VPre = 28, 132 OT_VPst = 29, 133 OT_T = 3, /* Tone Marks */ 134 // OT_A = 10, /* Anusvara */ 135 }; 136 137 static inline void 138 set_sea_properties (hb_glyph_info_t &info) 139 { 140 hb_codepoint_t u = info.codepoint; 141 unsigned int type = hb_indic_get_categories (u); 142 indic_category_t cat = (indic_category_t) (type & 0x7Fu); 143 indic_position_t pos = (indic_position_t) (type >> 8); 144 145 /* Medial Ra */ 146 if (u == 0x1A55u || u == 0xAA34u) 147 cat = (indic_category_t) OT_MR; 148 149 if (cat == OT_M) 150 { 151 switch ((int) pos) 152 { 153 case POS_PRE_C: cat = (indic_category_t) OT_VPre; break; 154 case POS_ABOVE_C: cat = (indic_category_t) OT_VAbv; break; 155 case POS_BELOW_C: cat = (indic_category_t) OT_VBlw; break; 156 case POS_POST_C: cat = (indic_category_t) OT_VPst; break; 157 } 158 } 159 160 info.sea_category() = (sea_category_t) cat; 161 info.sea_position() = pos; 162 } 163 164 165 static void 166 setup_masks_sea (const hb_ot_shape_plan_t *plan HB_UNUSED, 167 hb_buffer_t *buffer, 168 hb_font_t *font HB_UNUSED) 169 { 170 HB_BUFFER_ALLOCATE_VAR (buffer, sea_category); 171 HB_BUFFER_ALLOCATE_VAR (buffer, sea_position); 172 173 /* We cannot setup masks here. We save information about characters 174 * and setup masks later on in a pause-callback. */ 175 176 unsigned int count = buffer->len; 177 hb_glyph_info_t *info = buffer->info; 178 for (unsigned int i = 0; i < count; i++) 179 set_sea_properties (info[i]); 180 } 181 182 static void 183 setup_syllables (const hb_ot_shape_plan_t *plan HB_UNUSED, 184 hb_font_t *font HB_UNUSED, 185 hb_buffer_t *buffer) 186 { 187 find_syllables (buffer); 188 } 189 190 static int 191 compare_sea_order (const hb_glyph_info_t *pa, const hb_glyph_info_t *pb) 192 { 193 int a = pa->sea_position(); 194 int b = pb->sea_position(); 195 196 return a < b ? -1 : a == b ? 0 : +1; 197 } 198 199 200 static void 201 initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan, 202 hb_face_t *face, 203 hb_buffer_t *buffer, 204 unsigned int start, unsigned int end) 205 { 206 hb_glyph_info_t *info = buffer->info; 207 unsigned int base = start; 208 209 /* Reorder! */ 210 unsigned int i = start; 211 for (; i < base; i++) 212 info[i].sea_position() = POS_PRE_C; 213 if (i < end) 214 { 215 info[i].sea_position() = POS_BASE_C; 216 i++; 217 } 218 for (; i < end; i++) 219 { 220 if (info[i].sea_category() == OT_MR) /* Pre-base reordering */ 221 { 222 info[i].sea_position() = POS_PRE_C; 223 continue; 224 } 225 if (info[i].sea_category() == OT_VPre) /* Left matra */ 226 { 227 info[i].sea_position() = POS_PRE_M; 228 continue; 229 } 230 231 info[i].sea_position() = POS_AFTER_MAIN; 232 } 233 234 buffer->merge_clusters (start, end); 235 /* Sit tight, rock 'n roll! */ 236 hb_bubble_sort (info + start, end - start, compare_sea_order); 237 } 238 239 static void 240 initial_reordering_broken_cluster (const hb_ot_shape_plan_t *plan, 241 hb_face_t *face, 242 hb_buffer_t *buffer, 243 unsigned int start, unsigned int end) 244 { 245 /* We already inserted dotted-circles, so just call the consonant_syllable. */ 246 initial_reordering_consonant_syllable (plan, face, buffer, start, end); 247 } 248 249 static void 250 initial_reordering_non_sea_cluster (const hb_ot_shape_plan_t *plan HB_UNUSED, 251 hb_face_t *face HB_UNUSED, 252 hb_buffer_t *buffer HB_UNUSED, 253 unsigned int start HB_UNUSED, unsigned int end HB_UNUSED) 254 { 255 /* Nothing to do right now. If we ever switch to using the output 256 * buffer in the reordering process, we'd need to next_glyph() here. */ 257 } 258 259 260 static void 261 initial_reordering_syllable (const hb_ot_shape_plan_t *plan, 262 hb_face_t *face, 263 hb_buffer_t *buffer, 264 unsigned int start, unsigned int end) 265 { 266 syllable_type_t syllable_type = (syllable_type_t) (buffer->info[start].syllable() & 0x0F); 267 switch (syllable_type) { 268 case consonant_syllable: initial_reordering_consonant_syllable (plan, face, buffer, start, end); return; 269 case broken_cluster: initial_reordering_broken_cluster (plan, face, buffer, start, end); return; 270 case non_sea_cluster: initial_reordering_non_sea_cluster (plan, face, buffer, start, end); return; 271 } 272 } 273 274 static inline void 275 insert_dotted_circles (const hb_ot_shape_plan_t *plan HB_UNUSED, 276 hb_font_t *font, 277 hb_buffer_t *buffer) 278 { 279 /* Note: This loop is extra overhead, but should not be measurable. */ 280 bool has_broken_syllables = false; 281 unsigned int count = buffer->len; 282 hb_glyph_info_t *info = buffer->info; 283 for (unsigned int i = 0; i < count; i++) 284 if ((info[i].syllable() & 0x0F) == broken_cluster) 285 { 286 has_broken_syllables = true; 287 break; 288 } 289 if (likely (!has_broken_syllables)) 290 return; 291 292 293 hb_codepoint_t dottedcircle_glyph; 294 if (!font->get_glyph (0x25CCu, 0, &dottedcircle_glyph)) 295 return; 296 297 hb_glyph_info_t dottedcircle = {0}; 298 dottedcircle.codepoint = 0x25CCu; 299 set_sea_properties (dottedcircle); 300 dottedcircle.codepoint = dottedcircle_glyph; 301 302 buffer->clear_output (); 303 304 buffer->idx = 0; 305 unsigned int last_syllable = 0; 306 while (buffer->idx < buffer->len) 307 { 308 unsigned int syllable = buffer->cur().syllable(); 309 syllable_type_t syllable_type = (syllable_type_t) (syllable & 0x0F); 310 if (unlikely (last_syllable != syllable && syllable_type == broken_cluster)) 311 { 312 last_syllable = syllable; 313 314 hb_glyph_info_t info = dottedcircle; 315 info.cluster = buffer->cur().cluster; 316 info.mask = buffer->cur().mask; 317 info.syllable() = buffer->cur().syllable(); 318 319 buffer->output_info (info); 320 } 321 else 322 buffer->next_glyph (); 323 } 324 325 buffer->swap_buffers (); 326 } 327 328 static void 329 initial_reordering (const hb_ot_shape_plan_t *plan, 330 hb_font_t *font, 331 hb_buffer_t *buffer) 332 { 333 insert_dotted_circles (plan, font, buffer); 334 335 hb_glyph_info_t *info = buffer->info; 336 unsigned int count = buffer->len; 337 if (unlikely (!count)) return; 338 unsigned int last = 0; 339 unsigned int last_syllable = info[0].syllable(); 340 for (unsigned int i = 1; i < count; i++) 341 if (last_syllable != info[i].syllable()) { 342 initial_reordering_syllable (plan, font->face, buffer, last, i); 343 last = i; 344 last_syllable = info[last].syllable(); 345 } 346 initial_reordering_syllable (plan, font->face, buffer, last, count); 347 } 348 349 static void 350 final_reordering (const hb_ot_shape_plan_t *plan, 351 hb_font_t *font HB_UNUSED, 352 hb_buffer_t *buffer) 353 { 354 hb_glyph_info_t *info = buffer->info; 355 unsigned int count = buffer->len; 356 357 /* Zero syllables now... */ 358 for (unsigned int i = 0; i < count; i++) 359 info[i].syllable() = 0; 360 361 HB_BUFFER_DEALLOCATE_VAR (buffer, sea_category); 362 HB_BUFFER_DEALLOCATE_VAR (buffer, sea_position); 363 } 364 365 366 const hb_ot_complex_shaper_t _hb_ot_complex_shaper_sea = 367 { 368 "sea", 369 collect_features_sea, 370 override_features_sea, 371 NULL, /* data_create */ 372 NULL, /* data_destroy */ 373 NULL, /* preprocess_text */ 374 HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT, 375 NULL, /* decompose */ 376 NULL, /* compose */ 377 setup_masks_sea, 378 HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE, 379 false, /* fallback_position */ 380 }; 381
