1 /**************************************************************************** 2 * 3 * ttpload.c 4 * 5 * TrueType-specific tables loader (body). 6 * 7 * Copyright (C) 1996-2023 by 8 * David Turner, Robert Wilhelm, and Werner Lemberg. 9 * 10 * This file is part of the FreeType project, and may only be used, 11 * modified, and distributed under the terms of the FreeType project 12 * license, LICENSE.TXT. By continuing to use, modify, or distribute 13 * this file you indicate that you have read the license and 14 * understand and accept it fully. 15 * 16 */ 17 18 19 #include <freetype/internal/ftdebug.h> 20 #include <freetype/internal/ftobjs.h> 21 #include <freetype/internal/ftstream.h> 22 #include <freetype/tttags.h> 23 24 #include "ttpload.h" 25 26 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT 27 #include "ttgxvar.h" 28 #endif 29 30 #include "tterrors.h" 31 32 33 /************************************************************************** 34 * 35 * The macro FT_COMPONENT is used in trace mode. It is an implicit 36 * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log 37 * messages during execution. 38 */ 39 #undef FT_COMPONENT 40 #define FT_COMPONENT ttpload 41 42 43 /************************************************************************** 44 * 45 * @Function: 46 * tt_face_load_loca 47 * 48 * @Description: 49 * Load the locations table. 50 * 51 * @InOut: 52 * face :: 53 * A handle to the target face object. 54 * 55 * @Input: 56 * stream :: 57 * The input stream. 58 * 59 * @Return: 60 * FreeType error code. 0 means success. 61 */ 62 FT_LOCAL_DEF( FT_Error ) tt_face_load_loca(TT_Face face,FT_Stream stream)63 tt_face_load_loca( TT_Face face, 64 FT_Stream stream ) 65 { 66 FT_Error error; 67 FT_ULong table_len; 68 FT_Int shift; 69 70 71 /* we need the size of the `glyf' table for malformed `loca' tables */ 72 error = face->goto_table( face, TTAG_glyf, stream, &face->glyf_len ); 73 74 /* it is possible that a font doesn't have a glyf table at all */ 75 /* or its size is zero */ 76 if ( FT_ERR_EQ( error, Table_Missing ) ) 77 { 78 face->glyf_len = 0; 79 face->glyf_offset = 0; 80 } 81 else if ( error ) 82 goto Exit; 83 else 84 { 85 #ifdef FT_CONFIG_OPTION_INCREMENTAL 86 if ( face->root.internal->incremental_interface ) 87 face->glyf_offset = 0; 88 else 89 #endif 90 face->glyf_offset = FT_STREAM_POS(); 91 } 92 93 FT_TRACE2(( "Locations " )); 94 error = face->goto_table( face, TTAG_loca, stream, &table_len ); 95 if ( error ) 96 { 97 error = FT_THROW( Locations_Missing ); 98 goto Exit; 99 } 100 101 shift = face->header.Index_To_Loc_Format != 0 ? 2 : 1; 102 103 if ( table_len > 0x10000UL << shift ) 104 { 105 FT_TRACE2(( "table too large\n" )); 106 table_len = 0x10000UL << shift; 107 } 108 109 face->num_locations = table_len >> shift; 110 111 if ( face->num_locations != (FT_ULong)face->root.num_glyphs + 1 ) 112 { 113 FT_TRACE2(( "glyph count mismatch! loca: %ld, maxp: %ld\n", 114 face->num_locations - 1, face->root.num_glyphs )); 115 116 /* we only handle the case where `maxp' gives a larger value */ 117 if ( face->num_locations < (FT_ULong)face->root.num_glyphs + 1 ) 118 { 119 FT_ULong new_loca_len = 120 ( (FT_ULong)face->root.num_glyphs + 1 ) << shift; 121 122 TT_Table entry = face->dir_tables; 123 TT_Table limit = entry + face->num_tables; 124 125 FT_Long pos = (FT_Long)FT_STREAM_POS(); 126 FT_Long dist = 0x7FFFFFFFL; 127 FT_Bool found = 0; 128 129 130 /* compute the distance to next table in font file */ 131 for ( ; entry < limit; entry++ ) 132 { 133 FT_Long diff = (FT_Long)entry->Offset - pos; 134 135 136 if ( diff > 0 && diff < dist ) 137 { 138 dist = diff; 139 found = 1; 140 } 141 } 142 143 if ( !found ) 144 { 145 /* `loca' is the last table */ 146 dist = (FT_Long)stream->size - pos; 147 } 148 149 if ( new_loca_len <= (FT_ULong)dist ) 150 { 151 face->num_locations = (FT_ULong)face->root.num_glyphs + 1; 152 table_len = new_loca_len; 153 154 FT_TRACE2(( "adjusting num_locations to %ld\n", 155 face->num_locations )); 156 } 157 else 158 { 159 face->root.num_glyphs = face->num_locations 160 ? (FT_Long)face->num_locations - 1 : 0; 161 162 FT_TRACE2(( "adjusting num_glyphs to %ld\n", 163 face->root.num_glyphs )); 164 } 165 } 166 } 167 168 /* 169 * Extract the frame. We don't need to decompress it since 170 * we are able to parse it directly. 171 */ 172 if ( FT_FRAME_EXTRACT( table_len, face->glyph_locations ) ) 173 goto Exit; 174 175 FT_TRACE2(( "loaded\n" )); 176 177 Exit: 178 return error; 179 } 180 181 182 FT_LOCAL_DEF( FT_ULong ) tt_face_get_location(FT_Face face,FT_UInt gindex,FT_ULong * asize)183 tt_face_get_location( FT_Face face, /* TT_Face */ 184 FT_UInt gindex, 185 FT_ULong *asize ) 186 { 187 TT_Face ttface = (TT_Face)face; 188 FT_ULong pos1, pos2; 189 FT_Byte* p; 190 FT_Byte* p_limit; 191 192 193 pos1 = pos2 = 0; 194 195 if ( gindex < ttface->num_locations ) 196 { 197 if ( ttface->header.Index_To_Loc_Format != 0 ) 198 { 199 p = ttface->glyph_locations + gindex * 4; 200 p_limit = ttface->glyph_locations + ttface->num_locations * 4; 201 202 pos1 = FT_NEXT_ULONG( p ); 203 pos2 = pos1; 204 205 if ( p + 4 <= p_limit ) 206 pos2 = FT_NEXT_ULONG( p ); 207 } 208 else 209 { 210 p = ttface->glyph_locations + gindex * 2; 211 p_limit = ttface->glyph_locations + ttface->num_locations * 2; 212 213 pos1 = FT_NEXT_USHORT( p ); 214 pos2 = pos1; 215 216 if ( p + 2 <= p_limit ) 217 pos2 = FT_NEXT_USHORT( p ); 218 219 pos1 <<= 1; 220 pos2 <<= 1; 221 } 222 } 223 224 /* Check broken location data. */ 225 if ( pos1 > ttface->glyf_len ) 226 { 227 FT_TRACE1(( "tt_face_get_location:" 228 " too large offset (0x%08lx) found for glyph index %d,\n", 229 pos1, gindex )); 230 FT_TRACE1(( " " 231 " exceeding the end of `glyf' table (0x%08lx)\n", 232 ttface->glyf_len )); 233 *asize = 0; 234 return 0; 235 } 236 237 if ( pos2 > ttface->glyf_len ) 238 { 239 /* We try to sanitize the last `loca' entry. */ 240 if ( gindex == ttface->num_locations - 2 ) 241 { 242 FT_TRACE1(( "tt_face_get_location:" 243 " too large size (%ld bytes) found for glyph index %d,\n", 244 pos2 - pos1, gindex )); 245 FT_TRACE1(( " " 246 " truncating at the end of `glyf' table to %ld bytes\n", 247 ttface->glyf_len - pos1 )); 248 pos2 = ttface->glyf_len; 249 } 250 else 251 { 252 FT_TRACE1(( "tt_face_get_location:" 253 " too large offset (0x%08lx) found for glyph index %d,\n", 254 pos2, gindex + 1 )); 255 FT_TRACE1(( " " 256 " exceeding the end of `glyf' table (0x%08lx)\n", 257 ttface->glyf_len )); 258 *asize = 0; 259 return 0; 260 } 261 } 262 263 /* The `loca' table must be ordered; it refers to the length of */ 264 /* an entry as the difference between the current and the next */ 265 /* position. However, there do exist (malformed) fonts which */ 266 /* don't obey this rule, so we are only able to provide an */ 267 /* upper bound for the size. */ 268 /* */ 269 /* We get (intentionally) a wrong, non-zero result in case the */ 270 /* `glyf' table is missing. */ 271 if ( pos2 >= pos1 ) 272 *asize = (FT_ULong)( pos2 - pos1 ); 273 else 274 *asize = (FT_ULong)( ttface->glyf_len - pos1 ); 275 276 return pos1; 277 } 278 279 280 FT_LOCAL_DEF( void ) tt_face_done_loca(TT_Face face)281 tt_face_done_loca( TT_Face face ) 282 { 283 FT_Stream stream = face->root.stream; 284 285 286 FT_FRAME_RELEASE( face->glyph_locations ); 287 face->num_locations = 0; 288 } 289 290 291 292 /************************************************************************** 293 * 294 * @Function: 295 * tt_face_load_cvt 296 * 297 * @Description: 298 * Load the control value table into a face object. 299 * 300 * @InOut: 301 * face :: 302 * A handle to the target face object. 303 * 304 * @Input: 305 * stream :: 306 * A handle to the input stream. 307 * 308 * @Return: 309 * FreeType error code. 0 means success. 310 */ 311 FT_LOCAL_DEF( FT_Error ) tt_face_load_cvt(TT_Face face,FT_Stream stream)312 tt_face_load_cvt( TT_Face face, 313 FT_Stream stream ) 314 { 315 #ifdef TT_USE_BYTECODE_INTERPRETER 316 317 FT_Error error; 318 FT_Memory memory = stream->memory; 319 FT_ULong table_len; 320 321 322 FT_TRACE2(( "CVT " )); 323 324 error = face->goto_table( face, TTAG_cvt, stream, &table_len ); 325 if ( error ) 326 { 327 FT_TRACE2(( "is missing\n" )); 328 329 face->cvt_size = 0; 330 face->cvt = NULL; 331 error = FT_Err_Ok; 332 333 goto Exit; 334 } 335 336 face->cvt_size = table_len / 2; 337 338 if ( FT_QNEW_ARRAY( face->cvt, face->cvt_size ) ) 339 goto Exit; 340 341 if ( FT_FRAME_ENTER( face->cvt_size * 2L ) ) 342 goto Exit; 343 344 { 345 FT_Int32* cur = face->cvt; 346 FT_Int32* limit = cur + face->cvt_size; 347 348 349 for ( ; cur < limit; cur++ ) 350 *cur = FT_GET_SHORT() * 64; 351 } 352 353 FT_FRAME_EXIT(); 354 FT_TRACE2(( "loaded\n" )); 355 356 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT 357 if ( face->doblend ) 358 error = tt_face_vary_cvt( face, stream ); 359 #endif 360 361 Exit: 362 return error; 363 364 #else /* !TT_USE_BYTECODE_INTERPRETER */ 365 366 FT_UNUSED( face ); 367 FT_UNUSED( stream ); 368 369 return FT_Err_Ok; 370 371 #endif 372 } 373 374 375 /************************************************************************** 376 * 377 * @Function: 378 * tt_face_load_fpgm 379 * 380 * @Description: 381 * Load the font program. 382 * 383 * @InOut: 384 * face :: 385 * A handle to the target face object. 386 * 387 * @Input: 388 * stream :: 389 * A handle to the input stream. 390 * 391 * @Return: 392 * FreeType error code. 0 means success. 393 */ 394 FT_LOCAL_DEF( FT_Error ) tt_face_load_fpgm(TT_Face face,FT_Stream stream)395 tt_face_load_fpgm( TT_Face face, 396 FT_Stream stream ) 397 { 398 #ifdef TT_USE_BYTECODE_INTERPRETER 399 400 FT_Error error; 401 FT_ULong table_len; 402 403 404 FT_TRACE2(( "Font program " )); 405 406 /* The font program is optional */ 407 error = face->goto_table( face, TTAG_fpgm, stream, &table_len ); 408 if ( error ) 409 { 410 face->font_program = NULL; 411 face->font_program_size = 0; 412 error = FT_Err_Ok; 413 414 FT_TRACE2(( "is missing\n" )); 415 } 416 else 417 { 418 face->font_program_size = table_len; 419 if ( FT_FRAME_EXTRACT( table_len, face->font_program ) ) 420 goto Exit; 421 422 FT_TRACE2(( "loaded, %12ld bytes\n", face->font_program_size )); 423 } 424 425 Exit: 426 return error; 427 428 #else /* !TT_USE_BYTECODE_INTERPRETER */ 429 430 FT_UNUSED( face ); 431 FT_UNUSED( stream ); 432 433 return FT_Err_Ok; 434 435 #endif 436 } 437 438 439 /************************************************************************** 440 * 441 * @Function: 442 * tt_face_load_prep 443 * 444 * @Description: 445 * Load the cvt program. 446 * 447 * @InOut: 448 * face :: 449 * A handle to the target face object. 450 * 451 * @Input: 452 * stream :: 453 * A handle to the input stream. 454 * 455 * @Return: 456 * FreeType error code. 0 means success. 457 */ 458 FT_LOCAL_DEF( FT_Error ) tt_face_load_prep(TT_Face face,FT_Stream stream)459 tt_face_load_prep( TT_Face face, 460 FT_Stream stream ) 461 { 462 #ifdef TT_USE_BYTECODE_INTERPRETER 463 464 FT_Error error; 465 FT_ULong table_len; 466 467 468 FT_TRACE2(( "Prep program " )); 469 470 error = face->goto_table( face, TTAG_prep, stream, &table_len ); 471 if ( error ) 472 { 473 face->cvt_program = NULL; 474 face->cvt_program_size = 0; 475 error = FT_Err_Ok; 476 477 FT_TRACE2(( "is missing\n" )); 478 } 479 else 480 { 481 face->cvt_program_size = table_len; 482 if ( FT_FRAME_EXTRACT( table_len, face->cvt_program ) ) 483 goto Exit; 484 485 FT_TRACE2(( "loaded, %12ld bytes\n", face->cvt_program_size )); 486 } 487 488 Exit: 489 return error; 490 491 #else /* !TT_USE_BYTECODE_INTERPRETER */ 492 493 FT_UNUSED( face ); 494 FT_UNUSED( stream ); 495 496 return FT_Err_Ok; 497 498 #endif 499 } 500 501 502 FT_COMPARE_DEF( int ) compare_ppem(const void * a,const void * b)503 compare_ppem( const void* a, 504 const void* b ) 505 { 506 return **(FT_Byte**)a - **(FT_Byte**)b; 507 } 508 509 510 /************************************************************************** 511 * 512 * @Function: 513 * tt_face_load_hdmx 514 * 515 * @Description: 516 * Load the `hdmx' table into the face object. 517 * 518 * @Input: 519 * face :: 520 * A handle to the target face object. 521 * 522 * stream :: 523 * A handle to the input stream. 524 * 525 * @Return: 526 * FreeType error code. 0 means success. 527 */ 528 529 FT_LOCAL_DEF( FT_Error ) tt_face_load_hdmx(TT_Face face,FT_Stream stream)530 tt_face_load_hdmx( TT_Face face, 531 FT_Stream stream ) 532 { 533 FT_Error error; 534 FT_Memory memory = stream->memory; 535 FT_UInt nn, num_records; 536 FT_ULong table_size, record_size; 537 FT_Byte* p; 538 FT_Byte* limit; 539 540 541 /* this table is optional */ 542 error = face->goto_table( face, TTAG_hdmx, stream, &table_size ); 543 if ( error || table_size < 8 ) 544 return FT_Err_Ok; 545 546 if ( FT_FRAME_EXTRACT( table_size, face->hdmx_table ) ) 547 goto Exit; 548 549 p = face->hdmx_table; 550 limit = p + table_size; 551 552 /* Given that `hdmx' tables are losing its importance (for example, */ 553 /* variation fonts introduced in OpenType 1.8 must not have this */ 554 /* table) we no longer test for a correct `version' field. */ 555 p += 2; 556 num_records = FT_NEXT_USHORT( p ); 557 record_size = FT_NEXT_ULONG( p ); 558 559 /* There are at least two fonts, HANNOM-A and HANNOM-B version */ 560 /* 2.0 (2005), which get this wrong: The upper two bytes of */ 561 /* the size value are set to 0xFF instead of 0x00. We catch */ 562 /* and fix this. */ 563 564 if ( record_size >= 0xFFFF0000UL ) 565 record_size &= 0xFFFFU; 566 567 FT_TRACE2(( "Hdmx " )); 568 569 /* The limit for `num_records' is a heuristic value. */ 570 if ( num_records > 255 || num_records == 0 ) 571 { 572 FT_TRACE2(( "with unreasonable %u records rejected\n", num_records )); 573 goto Fail; 574 } 575 576 /* Out-of-spec tables are rejected. The record size must be */ 577 /* equal to the number of glyphs + 2 + 32-bit padding. */ 578 if ( (FT_Long)record_size != ( ( face->root.num_glyphs + 2 + 3 ) & ~3 ) ) 579 { 580 FT_TRACE2(( "with record size off by %ld bytes rejected\n", 581 (FT_Long)record_size - 582 ( ( face->root.num_glyphs + 2 + 3 ) & ~3 ) )); 583 goto Fail; 584 } 585 586 if ( FT_QNEW_ARRAY( face->hdmx_records, num_records ) ) 587 goto Fail; 588 589 for ( nn = 0; nn < num_records; nn++ ) 590 { 591 if ( p + record_size > limit ) 592 break; 593 face->hdmx_records[nn] = p; 594 p += record_size; 595 } 596 597 /* The records must be already sorted by ppem but it does not */ 598 /* hurt to make sure so that the binary search works later. */ 599 ft_qsort( face->hdmx_records, nn, sizeof ( FT_Byte* ), compare_ppem ); 600 601 face->hdmx_record_count = nn; 602 face->hdmx_table_size = table_size; 603 face->hdmx_record_size = record_size; 604 605 FT_TRACE2(( "%ux%lu loaded\n", num_records, record_size )); 606 607 Exit: 608 return error; 609 610 Fail: 611 FT_FRAME_RELEASE( face->hdmx_table ); 612 face->hdmx_table_size = 0; 613 goto Exit; 614 } 615 616 617 FT_LOCAL_DEF( void ) tt_face_free_hdmx(TT_Face face)618 tt_face_free_hdmx( TT_Face face ) 619 { 620 FT_Stream stream = face->root.stream; 621 FT_Memory memory = stream->memory; 622 623 624 FT_FREE( face->hdmx_records ); 625 FT_FRAME_RELEASE( face->hdmx_table ); 626 } 627 628 629 /************************************************************************** 630 * 631 * Return the advance width table for a given pixel size if it is found 632 * in the font's `hdmx' table (if any). The records must be sorted for 633 * the binary search to work properly. 634 */ 635 FT_LOCAL_DEF( FT_Byte* ) tt_face_get_device_metrics(TT_Face face,FT_UInt ppem,FT_UInt gindex)636 tt_face_get_device_metrics( TT_Face face, 637 FT_UInt ppem, 638 FT_UInt gindex ) 639 { 640 FT_UInt min = 0; 641 FT_UInt max = face->hdmx_record_count; 642 FT_UInt mid; 643 FT_Byte* result = NULL; 644 645 646 while ( min < max ) 647 { 648 mid = ( min + max ) >> 1; 649 650 if ( face->hdmx_records[mid][0] > ppem ) 651 max = mid; 652 else if ( face->hdmx_records[mid][0] < ppem ) 653 min = mid + 1; 654 else 655 { 656 result = face->hdmx_records[mid] + 2 + gindex; 657 break; 658 } 659 } 660 661 return result; 662 } 663 664 665 /* END */ 666