hb-buffer.cc revision 34db6f031d7ac009f554386ef990bad44886b9ee
1/* 2 * Copyright (C) 1998-2004 David Turner and Werner Lemberg 3 * Copyright (C) 2004,2007,2009,2010 Red Hat, 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): Owen Taylor, Behdad Esfahbod 26 */ 27 28#include "hb-buffer-private.hh" 29 30#include <string.h> 31 32HB_BEGIN_DECLS 33 34 35static hb_buffer_t _hb_buffer_nil = { 36 HB_REFERENCE_COUNT_INVALID, /* ref_count */ 37 38 &_hb_unicode_funcs_nil /* unicode */ 39}; 40 41/* Here is how the buffer works internally: 42 * 43 * There are two info pointers: info and out_info. They always have 44 * the same allocated size, but different lengths. 45 * 46 * As an optimization, both info and out_info may point to the 47 * same piece of memory, which is owned by info. This remains the 48 * case as long as out_len doesn't exceed len at any time. 49 * In that case, swap() is no-op and the glyph operations operate 50 * mostly in-place. 51 * 52 * As soon as out_info gets longer than info, out_info is moved over 53 * to an alternate buffer (which we reuse the pos buffer for!), and its 54 * current contents (out_len entries) are copied to the new place. 55 * This should all remain transparent to the user. swap() then 56 * switches info and out_info. 57 */ 58 59 60static hb_bool_t 61_hb_buffer_enlarge (hb_buffer_t *buffer, unsigned int size) 62{ 63 if (unlikely (buffer->in_error)) 64 return FALSE; 65 66 unsigned int new_allocated = buffer->allocated; 67 hb_internal_glyph_position_t *new_pos; 68 hb_internal_glyph_info_t *new_info; 69 bool separate_out; 70 71 separate_out = buffer->out_info != buffer->info; 72 73 while (size > new_allocated) 74 new_allocated += (new_allocated >> 1) + 8; 75 76 new_pos = (hb_internal_glyph_position_t *) realloc (buffer->pos, new_allocated * sizeof (buffer->pos[0])); 77 new_info = (hb_internal_glyph_info_t *) realloc (buffer->info, new_allocated * sizeof (buffer->info[0])); 78 79 if (unlikely (!new_pos || !new_info)) 80 buffer->in_error = TRUE; 81 82 if (likely (new_pos)) 83 buffer->pos = new_pos; 84 85 if (likely (new_info)) 86 buffer->info = new_info; 87 88 buffer->out_info = separate_out ? (hb_internal_glyph_info_t *) buffer->pos : buffer->info; 89 if (likely (!buffer->in_error)) 90 buffer->allocated = new_allocated; 91 92 return likely (!buffer->in_error); 93} 94 95static inline hb_bool_t 96_hb_buffer_ensure (hb_buffer_t *buffer, unsigned int size) 97{ 98 return likely (size <= buffer->allocated) ? TRUE : _hb_buffer_enlarge (buffer, size); 99} 100 101static inline hb_bool_t 102_hb_buffer_ensure_separate (hb_buffer_t *buffer, unsigned int size) 103{ 104 if (unlikely (!_hb_buffer_ensure (buffer, size))) return FALSE; 105 106 if (buffer->out_info == buffer->info) 107 { 108 assert (buffer->have_output); 109 110 buffer->out_info = (hb_internal_glyph_info_t *) buffer->pos; 111 memcpy (buffer->out_info, buffer->info, buffer->out_len * sizeof (buffer->out_info[0])); 112 } 113 114 return TRUE; 115} 116 117 118/* Public API */ 119 120hb_buffer_t * 121hb_buffer_create (unsigned int pre_alloc_size) 122{ 123 hb_buffer_t *buffer; 124 125 if (!HB_OBJECT_DO_CREATE (hb_buffer_t, buffer)) 126 return &_hb_buffer_nil; 127 128 if (pre_alloc_size) 129 _hb_buffer_ensure (buffer, pre_alloc_size); 130 131 buffer->unicode = &_hb_unicode_funcs_nil; 132 133 return buffer; 134} 135 136hb_buffer_t * 137hb_buffer_reference (hb_buffer_t *buffer) 138{ 139 HB_OBJECT_DO_REFERENCE (buffer); 140} 141 142unsigned int 143hb_buffer_get_reference_count (hb_buffer_t *buffer) 144{ 145 HB_OBJECT_DO_GET_REFERENCE_COUNT (buffer); 146} 147 148void 149hb_buffer_destroy (hb_buffer_t *buffer) 150{ 151 HB_OBJECT_DO_DESTROY (buffer); 152 153 hb_unicode_funcs_destroy (buffer->unicode); 154 155 free (buffer->info); 156 free (buffer->pos); 157 158 free (buffer); 159} 160 161 162void 163hb_buffer_set_unicode_funcs (hb_buffer_t *buffer, 164 hb_unicode_funcs_t *unicode) 165{ 166 if (!unicode) 167 unicode = &_hb_unicode_funcs_nil; 168 169 hb_unicode_funcs_reference (unicode); 170 hb_unicode_funcs_destroy (buffer->unicode); 171 buffer->unicode = unicode; 172} 173 174hb_unicode_funcs_t * 175hb_buffer_get_unicode_funcs (hb_buffer_t *buffer) 176{ 177 return buffer->unicode; 178} 179 180void 181hb_buffer_set_direction (hb_buffer_t *buffer, 182 hb_direction_t direction) 183 184{ 185 buffer->props.direction = direction; 186} 187 188hb_direction_t 189hb_buffer_get_direction (hb_buffer_t *buffer) 190{ 191 return buffer->props.direction; 192} 193 194void 195hb_buffer_set_script (hb_buffer_t *buffer, 196 hb_script_t script) 197{ 198 buffer->props.script = script; 199} 200 201hb_script_t 202hb_buffer_get_script (hb_buffer_t *buffer) 203{ 204 return buffer->props.script; 205} 206 207void 208hb_buffer_set_language (hb_buffer_t *buffer, 209 hb_language_t language) 210{ 211 buffer->props.language = language; 212} 213 214hb_language_t 215hb_buffer_get_language (hb_buffer_t *buffer) 216{ 217 return buffer->props.language; 218} 219 220 221void 222hb_buffer_clear (hb_buffer_t *buffer) 223{ 224 buffer->have_output = FALSE; 225 buffer->have_positions = FALSE; 226 buffer->in_error = FALSE; 227 buffer->len = 0; 228 buffer->out_len = 0; 229 buffer->i = 0; 230 buffer->out_info = buffer->info; 231 buffer->max_lig_id = 0; 232} 233 234hb_bool_t 235hb_buffer_ensure (hb_buffer_t *buffer, unsigned int size) 236{ 237 return _hb_buffer_ensure (buffer, size); 238} 239 240void 241hb_buffer_add_glyph (hb_buffer_t *buffer, 242 hb_codepoint_t codepoint, 243 hb_mask_t mask, 244 unsigned int cluster) 245{ 246 hb_internal_glyph_info_t *glyph; 247 248 if (unlikely (!_hb_buffer_ensure (buffer, buffer->len + 1))) return; 249 250 glyph = &buffer->info[buffer->len]; 251 glyph->codepoint = codepoint; 252 glyph->mask = mask; 253 glyph->cluster = cluster; 254 glyph->component = 0; 255 glyph->lig_id = 0; 256 glyph->gproperty = HB_BUFFER_GLYPH_PROPERTIES_UNKNOWN; 257 258 buffer->len++; 259} 260 261void 262hb_buffer_clear_positions (hb_buffer_t *buffer) 263{ 264 _hb_buffer_clear_output (buffer); 265 buffer->have_output = FALSE; 266 buffer->have_positions = TRUE; 267 268 if (unlikely (!buffer->pos)) 269 { 270 buffer->pos = (hb_internal_glyph_position_t *) calloc (buffer->allocated, sizeof (buffer->pos[0])); 271 return; 272 } 273 274 memset (buffer->pos, 0, sizeof (buffer->pos[0]) * buffer->len); 275} 276 277/* HarfBuzz-Internal API */ 278 279void 280_hb_buffer_clear_output (hb_buffer_t *buffer) 281{ 282 buffer->have_output = TRUE; 283 buffer->have_positions = FALSE; 284 buffer->out_len = 0; 285 buffer->out_info = buffer->info; 286} 287 288void 289_hb_buffer_swap (hb_buffer_t *buffer) 290{ 291 unsigned int tmp; 292 293 assert (buffer->have_output); 294 295 if (unlikely (buffer->in_error)) return; 296 297 if (buffer->out_info != buffer->info) 298 { 299 hb_internal_glyph_info_t *tmp_string; 300 tmp_string = buffer->info; 301 buffer->info = buffer->out_info; 302 buffer->out_info = tmp_string; 303 buffer->pos = (hb_internal_glyph_position_t *) buffer->out_info; 304 } 305 306 tmp = buffer->len; 307 buffer->len = buffer->out_len; 308 buffer->out_len = tmp; 309 310 buffer->i = 0; 311} 312 313/* The following function copies `num_out' elements from `glyph_data' 314 to `buffer->out_info', advancing the in array pointer in the structure 315 by `num_in' elements, and the out array pointer by `num_out' elements. 316 Finally, it sets the `length' field of `out' equal to 317 `pos' of the `out' structure. 318 319 If `component' is 0xFFFF, the component value from buffer->i 320 will copied `num_out' times, otherwise `component' itself will 321 be used to fill the `component' fields. 322 323 If `lig_id' is 0xFFFF, the lig_id value from buffer->i 324 will copied `num_out' times, otherwise `lig_id' itself will 325 be used to fill the `lig_id' fields. 326 327 The mask for all replacement glyphs are taken 328 from the glyph at position `buffer->i'. 329 330 The cluster value for the glyph at position buffer->i is used 331 for all replacement glyphs */ 332 333void 334_hb_buffer_add_output_glyphs (hb_buffer_t *buffer, 335 unsigned int num_in, 336 unsigned int num_out, 337 const hb_codepoint_t *glyph_data, 338 unsigned short component, 339 unsigned short lig_id) 340{ 341 unsigned int i; 342 unsigned int mask; 343 unsigned int cluster; 344 345 if (buffer->out_info != buffer->info || 346 buffer->out_len + num_out > buffer->i + num_in) 347 { 348 if (unlikely (!_hb_buffer_ensure_separate (buffer, buffer->out_len + num_out))) 349 return; 350 } 351 352 mask = buffer->info[buffer->i].mask; 353 cluster = buffer->info[buffer->i].cluster; 354 if (component == 0xFFFF) 355 component = buffer->info[buffer->i].component; 356 if (lig_id == 0xFFFF) 357 lig_id = buffer->info[buffer->i].lig_id; 358 359 for (i = 0; i < num_out; i++) 360 { 361 hb_internal_glyph_info_t *info = &buffer->out_info[buffer->out_len + i]; 362 info->codepoint = glyph_data[i]; 363 info->mask = mask; 364 info->cluster = cluster; 365 info->component = component; 366 info->lig_id = lig_id; 367 info->gproperty = HB_BUFFER_GLYPH_PROPERTIES_UNKNOWN; 368 } 369 370 buffer->i += num_in; 371 buffer->out_len += num_out; 372} 373 374void 375_hb_buffer_add_output_glyphs_be16 (hb_buffer_t *buffer, 376 unsigned int num_in, 377 unsigned int num_out, 378 const uint16_t *glyph_data_be, 379 unsigned short component, 380 unsigned short lig_id) 381{ 382 unsigned int i; 383 unsigned int mask; 384 unsigned int cluster; 385 386 if (buffer->out_info != buffer->info || 387 buffer->out_len + num_out > buffer->i + num_in) 388 { 389 if (unlikely (!_hb_buffer_ensure_separate (buffer, buffer->out_len + num_out))) 390 return; 391 } 392 393 mask = buffer->info[buffer->i].mask; 394 cluster = buffer->info[buffer->i].cluster; 395 if (component == 0xFFFF) 396 component = buffer->info[buffer->i].component; 397 if (lig_id == 0xFFFF) 398 lig_id = buffer->info[buffer->i].lig_id; 399 400 for (i = 0; i < num_out; i++) 401 { 402 hb_internal_glyph_info_t *info = &buffer->out_info[buffer->out_len + i]; 403 info->codepoint = hb_be_uint16 (glyph_data_be[i]); 404 info->mask = mask; 405 info->cluster = cluster; 406 info->component = component; 407 info->lig_id = lig_id; 408 info->gproperty = HB_BUFFER_GLYPH_PROPERTIES_UNKNOWN; 409 } 410 411 buffer->i += num_in; 412 buffer->out_len += num_out; 413} 414 415void 416_hb_buffer_add_output_glyph (hb_buffer_t *buffer, 417 hb_codepoint_t glyph_index, 418 unsigned short component, 419 unsigned short lig_id) 420{ 421 hb_internal_glyph_info_t *info; 422 423 if (buffer->out_info != buffer->info) 424 { 425 if (unlikely (!_hb_buffer_ensure (buffer, buffer->out_len + 1))) return; 426 buffer->out_info[buffer->out_len] = buffer->info[buffer->i]; 427 } 428 else if (buffer->out_len != buffer->i) 429 buffer->out_info[buffer->out_len] = buffer->info[buffer->i]; 430 431 info = &buffer->out_info[buffer->out_len]; 432 info->codepoint = glyph_index; 433 if (component != 0xFFFF) 434 info->component = component; 435 if (lig_id != 0xFFFF) 436 info->lig_id = lig_id; 437 info->gproperty = HB_BUFFER_GLYPH_PROPERTIES_UNKNOWN; 438 439 buffer->i++; 440 buffer->out_len++; 441} 442 443void 444_hb_buffer_next_glyph (hb_buffer_t *buffer) 445{ 446 if (buffer->have_output) 447 { 448 if (buffer->out_info != buffer->info) 449 { 450 if (unlikely (!_hb_buffer_ensure (buffer, buffer->out_len + 1))) return; 451 buffer->out_info[buffer->out_len] = buffer->info[buffer->i]; 452 } 453 else if (buffer->out_len != buffer->i) 454 buffer->out_info[buffer->out_len] = buffer->info[buffer->i]; 455 456 buffer->out_len++; 457 } 458 459 buffer->i++; 460} 461 462void 463_hb_buffer_clear_masks (hb_buffer_t *buffer) 464{ 465 unsigned int count = buffer->len; 466 for (unsigned int i = 0; i < count; i++) 467 buffer->info[i].mask = 1; 468} 469 470void 471_hb_buffer_set_masks (hb_buffer_t *buffer, 472 hb_mask_t value, 473 hb_mask_t mask, 474 unsigned int cluster_start, 475 unsigned int cluster_end) 476{ 477 hb_mask_t not_mask = ~mask; 478 479 if (cluster_start == 0 && cluster_end == (unsigned int)-1) { 480 unsigned int count = buffer->len; 481 for (unsigned int i = 0; i < count; i++) 482 buffer->info[i].mask = (buffer->info[i].mask & not_mask) | value; 483 return; 484 } 485 486 /* XXX can't bsearch since .cluster may not be sorted. */ 487 /* Binary search to find the start position and go from there. */ 488 unsigned int min = 0, max = buffer->len; 489 while (min < max) 490 { 491 unsigned int mid = min + ((max - min) / 2); 492 if (buffer->info[mid].cluster < cluster_start) 493 min = mid + 1; 494 else 495 max = mid; 496 } 497 unsigned int count = buffer->len; 498 for (unsigned int i = min; i < count && buffer->info[i].cluster < cluster_end; i++) 499 buffer->info[i].mask = (buffer->info[i].mask & not_mask) | value; 500} 501 502 503/* Public API again */ 504 505unsigned int 506hb_buffer_get_length (hb_buffer_t *buffer) 507{ 508 return buffer->len; 509} 510 511/* Return value valid as long as buffer not modified */ 512hb_glyph_info_t * 513hb_buffer_get_glyph_infos (hb_buffer_t *buffer) 514{ 515 return (hb_glyph_info_t *) buffer->info; 516} 517 518/* Return value valid as long as buffer not modified */ 519hb_glyph_position_t * 520hb_buffer_get_glyph_positions (hb_buffer_t *buffer) 521{ 522 if (!buffer->have_positions) 523 hb_buffer_clear_positions (buffer); 524 525 return (hb_glyph_position_t *) buffer->pos; 526} 527 528 529static void 530reverse_range (hb_buffer_t *buffer, 531 unsigned int start, 532 unsigned int end) 533{ 534 unsigned int i, j; 535 536 for (i = start, j = end - 1; i < j; i++, j--) { 537 hb_internal_glyph_info_t t; 538 539 t = buffer->info[i]; 540 buffer->info[i] = buffer->info[j]; 541 buffer->info[j] = t; 542 } 543 544 if (buffer->pos) { 545 for (i = 0, j = end - 1; i < j; i++, j--) { 546 hb_internal_glyph_position_t t; 547 548 t = buffer->pos[i]; 549 buffer->pos[i] = buffer->pos[j]; 550 buffer->pos[j] = t; 551 } 552 } 553} 554 555void 556hb_buffer_reverse (hb_buffer_t *buffer) 557{ 558 if (unlikely (!buffer->len)) 559 return; 560 561 reverse_range (buffer, 0, buffer->len); 562} 563 564void 565hb_buffer_reverse_clusters (hb_buffer_t *buffer) 566{ 567 unsigned int i, start, count, last_cluster; 568 569 if (unlikely (!buffer->len)) 570 return; 571 572 hb_buffer_reverse (buffer); 573 574 count = buffer->len; 575 start = 0; 576 last_cluster = buffer->info[0].cluster; 577 for (i = 1; i < count; i++) { 578 if (last_cluster != buffer->info[i].cluster) { 579 reverse_range (buffer, start, i); 580 start = i; 581 last_cluster = buffer->info[i].cluster; 582 } 583 } 584 reverse_range (buffer, start, i); 585} 586 587 588#define ADD_UTF(T) \ 589 HB_STMT_START { \ 590 const T *next = (const T *) text + item_offset; \ 591 const T *end = next + item_length; \ 592 while (next < end) { \ 593 hb_codepoint_t u; \ 594 const T *old_next = next; \ 595 next = UTF_NEXT (next, end, u); \ 596 hb_buffer_add_glyph (buffer, u, 1, old_next - (const T *) text); \ 597 } \ 598 } HB_STMT_END 599 600 601#define UTF8_COMPUTE(Char, Mask, Len) \ 602 if (Char < 128) { Len = 1; Mask = 0x7f; } \ 603 else if ((Char & 0xe0) == 0xc0) { Len = 2; Mask = 0x1f; } \ 604 else if ((Char & 0xf0) == 0xe0) { Len = 3; Mask = 0x0f; } \ 605 else if ((Char & 0xf8) == 0xf0) { Len = 4; Mask = 0x07; } \ 606 else Len = 0; 607 608static inline const uint8_t * 609hb_utf8_next (const uint8_t *text, 610 const uint8_t *end, 611 hb_codepoint_t *unicode) 612{ 613 uint8_t c = *text; 614 unsigned int mask, len; 615 616 /* TODO check for overlong sequences? also: optimize? */ 617 618 UTF8_COMPUTE (c, mask, len); 619 if (unlikely (!len || (unsigned int) (end - text) < len)) { 620 *unicode = -1; 621 return text + 1; 622 } else { 623 hb_codepoint_t result; 624 unsigned int i; 625 result = c & mask; 626 for (i = 1; i < len; i++) 627 { 628 if (unlikely ((text[i] & 0xc0) != 0x80)) 629 { 630 *unicode = -1; 631 return text + 1; 632 } 633 result <<= 6; 634 result |= (text[i] & 0x3f); 635 } 636 *unicode = result; 637 return text + len; 638 } 639} 640 641void 642hb_buffer_add_utf8 (hb_buffer_t *buffer, 643 const char *text, 644 unsigned int text_length HB_UNUSED, 645 unsigned int item_offset, 646 unsigned int item_length) 647{ 648#define UTF_NEXT(S, E, U) hb_utf8_next (S, E, &(U)) 649 ADD_UTF (uint8_t); 650#undef UTF_NEXT 651} 652 653static inline const uint16_t * 654hb_utf16_next (const uint16_t *text, 655 const uint16_t *end, 656 hb_codepoint_t *unicode) 657{ 658 uint16_t c = *text++; 659 660 if (unlikely (c >= 0xd800 && c < 0xdc00)) { 661 /* high surrogate */ 662 uint16_t l; 663 if (text < end && ((l = *text), unlikely (l >= 0xdc00 && l < 0xe000))) { 664 /* low surrogate */ 665 *unicode = ((hb_codepoint_t) ((c) - 0xd800) * 0x400 + (l) - 0xdc00 + 0x10000); 666 text++; 667 } else 668 *unicode = -1; 669 } else 670 *unicode = c; 671 672 return text; 673} 674 675void 676hb_buffer_add_utf16 (hb_buffer_t *buffer, 677 const uint16_t *text, 678 unsigned int text_length HB_UNUSED, 679 unsigned int item_offset, 680 unsigned int item_length) 681{ 682#define UTF_NEXT(S, E, U) hb_utf16_next (S, E, &(U)) 683 ADD_UTF (uint16_t); 684#undef UTF_NEXT 685} 686 687void 688hb_buffer_add_utf32 (hb_buffer_t *buffer, 689 const uint32_t *text, 690 unsigned int text_length HB_UNUSED, 691 unsigned int item_offset, 692 unsigned int item_length) 693{ 694#define UTF_NEXT(S, E, U) ((U) = *(S), (S)+1) 695 ADD_UTF (uint32_t); 696#undef UTF_NEXT 697} 698 699 700HB_END_DECLS 701