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 */ 38enum { 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 58static 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 97static 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 */ 112enum { 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 128static 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 159static void 160arabic_fallback_shape (const hb_ot_shape_plan_t *plan, 161 hb_font_t *font, 162 hb_buffer_t *buffer); 163 164static void 165collect_features_arabic (hb_ot_shape_planner_t *plan) 166{ 167 hb_ot_map_builder_t *map = &plan->map; 168 169 /* For Language forms (in ArabicOT speak), we do the iso/fina/medi/init together, 170 * then rlig and calt each in their own stage. This makes IranNastaliq's ALLAH 171 * ligature work correctly. It's unfortunate though... 172 * 173 * This also makes Arial Bold in Windows7 work. See: 174 * https://bugzilla.mozilla.org/show_bug.cgi?id=644184 175 * 176 * TODO: Add test cases for these two. 177 */ 178 179 map->add_global_bool_feature (HB_TAG('c','c','m','p')); 180 map->add_global_bool_feature (HB_TAG('l','o','c','l')); 181 182 map->add_gsub_pause (NULL); 183 184 for (unsigned int i = 0; i < ARABIC_NUM_FEATURES; i++) 185 map->add_feature (arabic_features[i], 1, i < 4 ? F_HAS_FALLBACK : F_NONE); /* The first four features have fallback. */ 186 187 map->add_gsub_pause (NULL); 188 189 map->add_feature (HB_TAG('r','l','i','g'), 1, F_GLOBAL|F_HAS_FALLBACK); 190 map->add_gsub_pause (arabic_fallback_shape); 191 192 map->add_global_bool_feature (HB_TAG('c','a','l','t')); 193 map->add_gsub_pause (NULL); 194 195 map->add_global_bool_feature (HB_TAG('c','s','w','h')); 196 map->add_global_bool_feature (HB_TAG('d','l','i','g')); 197 map->add_global_bool_feature (HB_TAG('m','s','e','t')); 198} 199 200#include "hb-ot-shape-complex-arabic-fallback.hh" 201 202struct arabic_shape_plan_t 203{ 204 ASSERT_POD (); 205 206 /* The "+ 1" in the next array is to accommodate for the "NONE" command, 207 * which is not an OpenType feature, but this simplifies the code by not 208 * having to do a "if (... < NONE) ..." and just rely on the fact that 209 * mask_array[NONE] == 0. */ 210 hb_mask_t mask_array[ARABIC_NUM_FEATURES + 1]; 211 212 bool do_fallback; 213 arabic_fallback_plan_t *fallback_plan; 214}; 215 216static void * 217data_create_arabic (const hb_ot_shape_plan_t *plan) 218{ 219 arabic_shape_plan_t *arabic_plan = (arabic_shape_plan_t *) calloc (1, sizeof (arabic_shape_plan_t)); 220 if (unlikely (!arabic_plan)) 221 return NULL; 222 223 arabic_plan->do_fallback = plan->props.script == HB_SCRIPT_ARABIC; 224 for (unsigned int i = 0; i < ARABIC_NUM_FEATURES; i++) { 225 arabic_plan->mask_array[i] = plan->map.get_1_mask (arabic_features[i]); 226 if (i < 4) 227 arabic_plan->do_fallback = arabic_plan->do_fallback && plan->map.needs_fallback (arabic_features[i]); 228 } 229 230 return arabic_plan; 231} 232 233static void 234data_destroy_arabic (void *data) 235{ 236 arabic_shape_plan_t *arabic_plan = (arabic_shape_plan_t *) data; 237 238 arabic_fallback_plan_destroy (arabic_plan->fallback_plan); 239 240 free (data); 241} 242 243static void 244arabic_joining (hb_buffer_t *buffer) 245{ 246 unsigned int count = buffer->len; 247 unsigned int prev = (unsigned int) -1, state = 0; 248 249 HB_BUFFER_ALLOCATE_VAR (buffer, arabic_shaping_action); 250 251 /* Check pre-context */ 252 if (!(buffer->flags & HB_BUFFER_FLAG_BOT)) 253 for (unsigned int i = 0; i < buffer->context_len[0]; i++) 254 { 255 unsigned int this_type = get_joining_type (buffer->context[0][i], buffer->unicode->general_category (buffer->context[0][i])); 256 257 if (unlikely (this_type == JOINING_TYPE_T)) 258 continue; 259 260 const arabic_state_table_entry *entry = &arabic_state_table[state][this_type]; 261 state = entry->next_state; 262 break; 263 } 264 265 for (unsigned int i = 0; i < count; i++) 266 { 267 unsigned int this_type = get_joining_type (buffer->info[i].codepoint, _hb_glyph_info_get_general_category (&buffer->info[i])); 268 269 if (unlikely (this_type == JOINING_TYPE_T)) { 270 buffer->info[i].arabic_shaping_action() = NONE; 271 continue; 272 } 273 274 const arabic_state_table_entry *entry = &arabic_state_table[state][this_type]; 275 276 if (entry->prev_action != NONE && prev != (unsigned int) -1) 277 buffer->info[prev].arabic_shaping_action() = entry->prev_action; 278 279 buffer->info[i].arabic_shaping_action() = entry->curr_action; 280 281 prev = i; 282 state = entry->next_state; 283 } 284 285 if (!(buffer->flags & HB_BUFFER_FLAG_EOT)) 286 for (unsigned int i = 0; i < buffer->context_len[1]; i++) 287 { 288 unsigned int this_type = get_joining_type (buffer->context[1][i], buffer->unicode->general_category (buffer->context[1][i])); 289 290 if (unlikely (this_type == JOINING_TYPE_T)) 291 continue; 292 293 const arabic_state_table_entry *entry = &arabic_state_table[state][this_type]; 294 if (entry->prev_action != NONE && prev != (unsigned int) -1) 295 buffer->info[prev].arabic_shaping_action() = entry->prev_action; 296 break; 297 } 298 299 300 HB_BUFFER_DEALLOCATE_VAR (buffer, arabic_shaping_action); 301} 302 303static void 304setup_masks_arabic (const hb_ot_shape_plan_t *plan, 305 hb_buffer_t *buffer, 306 hb_font_t *font HB_UNUSED) 307{ 308 const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data; 309 310 arabic_joining (buffer); 311 unsigned int count = buffer->len; 312 for (unsigned int i = 0; i < count; i++) 313 buffer->info[i].mask |= arabic_plan->mask_array[buffer->info[i].arabic_shaping_action()]; 314} 315 316 317static void 318arabic_fallback_shape (const hb_ot_shape_plan_t *plan, 319 hb_font_t *font, 320 hb_buffer_t *buffer) 321{ 322 const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data; 323 324 if (!arabic_plan->do_fallback) 325 return; 326 327retry: 328 arabic_fallback_plan_t *fallback_plan = (arabic_fallback_plan_t *) hb_atomic_ptr_get (&arabic_plan->fallback_plan); 329 if (unlikely (!fallback_plan)) 330 { 331 /* This sucks. We need a font to build the fallback plan... */ 332 fallback_plan = arabic_fallback_plan_create (plan, font); 333 if (unlikely (!hb_atomic_ptr_cmpexch (&(const_cast<arabic_shape_plan_t *> (arabic_plan))->fallback_plan, NULL, fallback_plan))) { 334 arabic_fallback_plan_destroy (fallback_plan); 335 goto retry; 336 } 337 } 338 339 arabic_fallback_plan_shape (fallback_plan, font, buffer); 340} 341 342 343const hb_ot_complex_shaper_t _hb_ot_complex_shaper_arabic = 344{ 345 "arabic", 346 collect_features_arabic, 347 NULL, /* override_features */ 348 data_create_arabic, 349 data_destroy_arabic, 350 NULL, /* preprocess_text_arabic */ 351 NULL, /* normalization_preference */ 352 NULL, /* decompose */ 353 NULL, /* compose */ 354 setup_masks_arabic, 355 HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE, 356 true, /* fallback_position */ 357}; 358