1 /* 2 * Copyright 2010,2012 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-private.hh" 28 #include "hb-ot-shape-private.hh" 29 30 31 /* buffer var allocations */ 32 #define arabic_shaping_action() complex_var_u8_0() /* arabic shaping action */ 33 34 35 /* 36 * Bits used in the joining tables 37 */ 38 enum { 39 JOINING_TYPE_U = 0, 40 JOINING_TYPE_L = 1, 41 JOINING_TYPE_R = 2, 42 JOINING_TYPE_D = 3, 43 JOINING_TYPE_C = JOINING_TYPE_D, 44 JOINING_GROUP_ALAPH = 4, 45 JOINING_GROUP_DALATH_RISH = 5, 46 NUM_STATE_MACHINE_COLS = 6, 47 48 JOINING_TYPE_T = 7, 49 JOINING_TYPE_X = 8 /* means: use general-category to choose between U or T. */ 50 }; 51 52 /* 53 * Joining types: 54 */ 55 56 #include "hb-ot-shape-complex-arabic-table.hh" 57 58 static unsigned int get_joining_type (hb_codepoint_t u, hb_unicode_general_category_t gen_cat) 59 { 60 if (likely (hb_in_range<hb_codepoint_t> (u, JOINING_TABLE_FIRST, JOINING_TABLE_LAST))) { 61 unsigned int j_type = joining_table[u - JOINING_TABLE_FIRST]; 62 if (likely (j_type != JOINING_TYPE_X)) 63 return j_type; 64 } 65 66 /* Mongolian joining data is not in ArabicJoining.txt yet. */ 67 if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x1800, 0x18AF))) 68 { 69 if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x1880, 0x1886))) 70 return JOINING_TYPE_U; 71 72 /* All letters, SIBE SYLLABLE BOUNDARY MARKER, and NIRUGU are D */ 73 if ((FLAG(gen_cat) & (FLAG (HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER) | 74 FLAG (HB_UNICODE_GENERAL_CATEGORY_MODIFIER_LETTER))) 75 || u == 0x1807 || u == 0x180A) 76 return JOINING_TYPE_D; 77 } 78 79 /* 'Phags-pa joining data is not in ArabicJoining.txt yet. */ 80 if (unlikely (hb_in_range<hb_codepoint_t> (u, 0xA840, 0xA872))) 81 { 82 if (unlikely (u == 0xA872)) 83 return JOINING_TYPE_L; 84 85 return JOINING_TYPE_D; 86 } 87 88 if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x200C, 0x200D))) 89 { 90 return u == 0x200C ? JOINING_TYPE_U : JOINING_TYPE_C; 91 } 92 93 return (FLAG(gen_cat) & (FLAG(HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) | FLAG(HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK) | FLAG(HB_UNICODE_GENERAL_CATEGORY_FORMAT))) ? 94 JOINING_TYPE_T : JOINING_TYPE_U; 95 } 96 97 static const hb_tag_t arabic_features[] = 98 { 99 HB_TAG('i','n','i','t'), 100 HB_TAG('m','e','d','i'), 101 HB_TAG('f','i','n','a'), 102 HB_TAG('i','s','o','l'), 103 /* Syriac */ 104 HB_TAG('m','e','d','2'), 105 HB_TAG('f','i','n','2'), 106 HB_TAG('f','i','n','3'), 107 HB_TAG_NONE 108 }; 109 110 111 /* Same order as the feature array */ 112 enum { 113 INIT, 114 MEDI, 115 FINA, 116 ISOL, 117 118 /* Syriac */ 119 MED2, 120 FIN2, 121 FIN3, 122 123 NONE, 124 125 ARABIC_NUM_FEATURES = NONE 126 }; 127 128 static const struct arabic_state_table_entry { 129 uint8_t prev_action; 130 uint8_t curr_action; 131 uint16_t next_state; 132 } arabic_state_table[][NUM_STATE_MACHINE_COLS] = 133 { 134 /* jt_U, jt_L, jt_R, jt_D, jg_ALAPH, jg_DALATH_RISH */ 135 136 /* State 0: prev was U, not willing to join. */ 137 { {NONE,NONE,0}, {NONE,ISOL,2}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,ISOL,1}, {NONE,ISOL,6}, }, 138 139 /* State 1: prev was R or ISOL/ALAPH, not willing to join. */ 140 { {NONE,NONE,0}, {NONE,ISOL,2}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,FIN2,5}, {NONE,ISOL,6}, }, 141 142 /* State 2: prev was D/L in ISOL form, willing to join. */ 143 { {NONE,NONE,0}, {NONE,ISOL,2}, {INIT,FINA,1}, {INIT,FINA,3}, {INIT,FINA,4}, {INIT,FINA,6}, }, 144 145 /* State 3: prev was D in FINA form, willing to join. */ 146 { {NONE,NONE,0}, {NONE,ISOL,2}, {MEDI,FINA,1}, {MEDI,FINA,3}, {MEDI,FINA,4}, {MEDI,FINA,6}, }, 147 148 /* State 4: prev was FINA ALAPH, not willing to join. */ 149 { {NONE,NONE,0}, {NONE,ISOL,2}, {MED2,ISOL,1}, {MED2,ISOL,2}, {MED2,FIN2,5}, {MED2,ISOL,6}, }, 150 151 /* State 5: prev was FIN2/FIN3 ALAPH, not willing to join. */ 152 { {NONE,NONE,0}, {NONE,ISOL,2}, {ISOL,ISOL,1}, {ISOL,ISOL,2}, {ISOL,FIN2,5}, {ISOL,ISOL,6}, }, 153 154 /* State 6: prev was DALATH/RISH, not willing to join. */ 155 { {NONE,NONE,0}, {NONE,ISOL,2}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,FIN3,5}, {NONE,ISOL,6}, } 156 }; 157 158 159 static void 160 nuke_joiners (const hb_ot_shape_plan_t *plan, 161 hb_font_t *font, 162 hb_buffer_t *buffer); 163 164 static void 165 arabic_fallback_shape (const hb_ot_shape_plan_t *plan, 166 hb_font_t *font, 167 hb_buffer_t *buffer); 168 169 static void 170 collect_features_arabic (hb_ot_shape_planner_t *plan) 171 { 172 hb_ot_map_builder_t *map = &plan->map; 173 174 /* For Language forms (in ArabicOT speak), we do the iso/fina/medi/init together, 175 * then rlig and calt each in their own stage. This makes IranNastaliq's ALLAH 176 * ligature work correctly. It's unfortunate though... 177 * 178 * This also makes Arial Bold in Windows7 work. See: 179 * https://bugzilla.mozilla.org/show_bug.cgi?id=644184 180 * 181 * TODO: Add test cases for these two. 182 */ 183 184 map->add_gsub_pause (nuke_joiners); 185 186 map->add_global_bool_feature (HB_TAG('c','c','m','p')); 187 map->add_global_bool_feature (HB_TAG('l','o','c','l')); 188 189 map->add_gsub_pause (NULL); 190 191 for (unsigned int i = 0; i < ARABIC_NUM_FEATURES; i++) 192 map->add_feature (arabic_features[i], 1, i < 4 ? F_HAS_FALLBACK : F_NONE); /* The first four features have fallback. */ 193 194 map->add_gsub_pause (NULL); 195 196 map->add_feature (HB_TAG('r','l','i','g'), 1, F_GLOBAL|F_HAS_FALLBACK); 197 map->add_gsub_pause (arabic_fallback_shape); 198 199 map->add_global_bool_feature (HB_TAG('c','a','l','t')); 200 map->add_gsub_pause (NULL); 201 202 map->add_global_bool_feature (HB_TAG('m','s','e','t')); 203 } 204 205 #include "hb-ot-shape-complex-arabic-fallback.hh" 206 207 struct arabic_shape_plan_t 208 { 209 ASSERT_POD (); 210 211 /* The "+ 1" in the next array is to accommodate for the "NONE" command, 212 * which is not an OpenType feature, but this simplifies the code by not 213 * having to do a "if (... < NONE) ..." and just rely on the fact that 214 * mask_array[NONE] == 0. */ 215 hb_mask_t mask_array[ARABIC_NUM_FEATURES + 1]; 216 217 bool do_fallback; 218 arabic_fallback_plan_t *fallback_plan; 219 }; 220 221 static void * 222 data_create_arabic (const hb_ot_shape_plan_t *plan) 223 { 224 arabic_shape_plan_t *arabic_plan = (arabic_shape_plan_t *) calloc (1, sizeof (arabic_shape_plan_t)); 225 if (unlikely (!arabic_plan)) 226 return NULL; 227 228 arabic_plan->do_fallback = plan->props.script == HB_SCRIPT_ARABIC; 229 for (unsigned int i = 0; i < ARABIC_NUM_FEATURES; i++) { 230 arabic_plan->mask_array[i] = plan->map.get_1_mask (arabic_features[i]); 231 if (i < 4) 232 arabic_plan->do_fallback = arabic_plan->do_fallback && plan->map.needs_fallback (arabic_features[i]); 233 } 234 235 return arabic_plan; 236 } 237 238 static void 239 data_destroy_arabic (void *data) 240 { 241 arabic_shape_plan_t *arabic_plan = (arabic_shape_plan_t *) data; 242 243 arabic_fallback_plan_destroy (arabic_plan->fallback_plan); 244 245 free (data); 246 } 247 248 static void 249 arabic_joining (hb_buffer_t *buffer) 250 { 251 unsigned int count = buffer->len; 252 unsigned int prev = (unsigned int) -1, state = 0; 253 254 HB_BUFFER_ALLOCATE_VAR (buffer, arabic_shaping_action); 255 256 /* Check pre-context */ 257 if (!(buffer->flags & HB_BUFFER_FLAG_BOT)) 258 for (unsigned int i = 0; i < buffer->context_len[0]; i++) 259 { 260 unsigned int this_type = get_joining_type (buffer->context[0][i], buffer->unicode->general_category (buffer->context[0][i])); 261 262 if (unlikely (this_type == JOINING_TYPE_T)) 263 continue; 264 265 const arabic_state_table_entry *entry = &arabic_state_table[state][this_type]; 266 state = entry->next_state; 267 break; 268 } 269 270 for (unsigned int i = 0; i < count; i++) 271 { 272 unsigned int this_type = get_joining_type (buffer->info[i].codepoint, _hb_glyph_info_get_general_category (&buffer->info[i])); 273 274 if (unlikely (this_type == JOINING_TYPE_T)) { 275 buffer->info[i].arabic_shaping_action() = NONE; 276 continue; 277 } 278 279 const arabic_state_table_entry *entry = &arabic_state_table[state][this_type]; 280 281 if (entry->prev_action != NONE && prev != (unsigned int) -1) 282 for (; prev < i; prev++) 283 buffer->info[prev].arabic_shaping_action() = entry->prev_action; 284 285 buffer->info[i].arabic_shaping_action() = entry->curr_action; 286 287 prev = i; 288 state = entry->next_state; 289 } 290 291 if (!(buffer->flags & HB_BUFFER_FLAG_EOT)) 292 for (unsigned int i = 0; i < buffer->context_len[1]; i++) 293 { 294 unsigned int this_type = get_joining_type (buffer->context[1][i], buffer->unicode->general_category (buffer->context[1][i])); 295 296 if (unlikely (this_type == JOINING_TYPE_T)) 297 continue; 298 299 const arabic_state_table_entry *entry = &arabic_state_table[state][this_type]; 300 if (entry->prev_action != NONE && prev != (unsigned int) -1) 301 buffer->info[prev].arabic_shaping_action() = entry->prev_action; 302 break; 303 } 304 305 306 HB_BUFFER_DEALLOCATE_VAR (buffer, arabic_shaping_action); 307 } 308 309 static void 310 setup_masks_arabic (const hb_ot_shape_plan_t *plan, 311 hb_buffer_t *buffer, 312 hb_font_t *font HB_UNUSED) 313 { 314 const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data; 315 316 arabic_joining (buffer); 317 unsigned int count = buffer->len; 318 for (unsigned int i = 0; i < count; i++) 319 buffer->info[i].mask |= arabic_plan->mask_array[buffer->info[i].arabic_shaping_action()]; 320 } 321 322 323 static void 324 nuke_joiners (const hb_ot_shape_plan_t *plan HB_UNUSED, 325 hb_font_t *font HB_UNUSED, 326 hb_buffer_t *buffer) 327 { 328 unsigned int count = buffer->len; 329 for (unsigned int i = 0; i < count; i++) 330 if (_hb_glyph_info_is_zwj (&buffer->info[i])) 331 _hb_glyph_info_flip_joiners (&buffer->info[i]); 332 } 333 334 static void 335 arabic_fallback_shape (const hb_ot_shape_plan_t *plan, 336 hb_font_t *font, 337 hb_buffer_t *buffer) 338 { 339 const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data; 340 341 if (!arabic_plan->do_fallback) 342 return; 343 344 retry: 345 arabic_fallback_plan_t *fallback_plan = (arabic_fallback_plan_t *) hb_atomic_ptr_get (&arabic_plan->fallback_plan); 346 if (unlikely (!fallback_plan)) 347 { 348 /* This sucks. We need a font to build the fallback plan... */ 349 fallback_plan = arabic_fallback_plan_create (plan, font); 350 if (unlikely (!hb_atomic_ptr_cmpexch (&(const_cast<arabic_shape_plan_t *> (arabic_plan))->fallback_plan, NULL, fallback_plan))) { 351 arabic_fallback_plan_destroy (fallback_plan); 352 goto retry; 353 } 354 } 355 356 arabic_fallback_plan_shape (fallback_plan, font, buffer); 357 } 358 359 360 const hb_ot_complex_shaper_t _hb_ot_complex_shaper_arabic = 361 { 362 "arabic", 363 collect_features_arabic, 364 NULL, /* override_features */ 365 data_create_arabic, 366 data_destroy_arabic, 367 NULL, /* preprocess_text_arabic */ 368 HB_OT_SHAPE_NORMALIZATION_MODE_DEFAULT, 369 NULL, /* decompose */ 370 NULL, /* compose */ 371 setup_masks_arabic, 372 HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE, 373 true, /* fallback_position */ 374 }; 375
