1 /**************************************************************************** 2 * 3 * ttpload.c 4 * 5 * TrueType-specific tables loader (body). 6 * 7 * Copyright 1996-2018 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 <ft2build.h> 20 #include FT_INTERNAL_DEBUG_H 21 #include FT_INTERNAL_OBJECTS_H 22 #include FT_INTERNAL_STREAM_H 23 #include FT_TRUETYPE_TAGS_H 24 25 #include "ttpload.h" 26 27 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT 28 #include "ttgxvar.h" 29 #endif 30 31 #include "tterrors.h" 32 33 34 /************************************************************************** 35 * 36 * The macro FT_COMPONENT is used in trace mode. It is an implicit 37 * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log 38 * messages during execution. 39 */ 40 #undef FT_COMPONENT 41 #define FT_COMPONENT trace_ttpload 42 43 44 /************************************************************************** 45 * 46 * @Function: 47 * tt_face_load_loca 48 * 49 * @Description: 50 * Load the locations table. 51 * 52 * @InOut: 53 * face :: 54 * A handle to the target face object. 55 * 56 * @Input: 57 * stream :: 58 * The input stream. 59 * 60 * @Return: 61 * FreeType error code. 0 means success. 62 */ 63 FT_LOCAL_DEF( FT_Error ) tt_face_load_loca(TT_Face face,FT_Stream stream)64 tt_face_load_loca( TT_Face face, 65 FT_Stream stream ) 66 { 67 FT_Error error; 68 FT_ULong table_len; 69 FT_Int shift; 70 71 72 /* we need the size of the `glyf' table for malformed `loca' tables */ 73 error = face->goto_table( face, TTAG_glyf, stream, &face->glyf_len ); 74 75 /* it is possible that a font doesn't have a glyf table at all */ 76 /* or its size is zero */ 77 if ( FT_ERR_EQ( error, Table_Missing ) ) 78 { 79 face->glyf_len = 0; 80 face->glyf_offset = 0; 81 } 82 else if ( error ) 83 goto Exit; 84 else 85 { 86 #ifdef FT_CONFIG_OPTION_INCREMENTAL 87 if ( face->root.internal->incremental_interface ) 88 face->glyf_offset = 0; 89 else 90 #endif 91 face->glyf_offset = FT_STREAM_POS(); 92 } 93 94 FT_TRACE2(( "Locations " )); 95 error = face->goto_table( face, TTAG_loca, stream, &table_len ); 96 if ( error ) 97 { 98 error = FT_THROW( Locations_Missing ); 99 goto Exit; 100 } 101 102 if ( face->header.Index_To_Loc_Format != 0 ) 103 { 104 shift = 2; 105 106 if ( table_len >= 0x40000L ) 107 { 108 FT_TRACE2(( "table too large\n" )); 109 table_len = 0x3FFFFL; 110 } 111 face->num_locations = table_len >> shift; 112 } 113 else 114 { 115 shift = 1; 116 117 if ( table_len >= 0x20000L ) 118 { 119 FT_TRACE2(( "table too large\n" )); 120 table_len = 0x1FFFFL; 121 } 122 face->num_locations = table_len >> shift; 123 } 124 125 if ( face->num_locations != (FT_ULong)face->root.num_glyphs + 1 ) 126 { 127 FT_TRACE2(( "glyph count mismatch! loca: %d, maxp: %d\n", 128 face->num_locations - 1, face->root.num_glyphs )); 129 130 /* we only handle the case where `maxp' gives a larger value */ 131 if ( face->num_locations <= (FT_ULong)face->root.num_glyphs ) 132 { 133 FT_ULong new_loca_len = 134 ( (FT_ULong)face->root.num_glyphs + 1 ) << shift; 135 136 TT_Table entry = face->dir_tables; 137 TT_Table limit = entry + face->num_tables; 138 139 FT_Long pos = (FT_Long)FT_STREAM_POS(); 140 FT_Long dist = 0x7FFFFFFFL; 141 FT_Bool found = 0; 142 143 144 /* compute the distance to next table in font file */ 145 for ( ; entry < limit; entry++ ) 146 { 147 FT_Long diff = (FT_Long)entry->Offset - pos; 148 149 150 if ( diff > 0 && diff < dist ) 151 { 152 dist = diff; 153 found = 1; 154 } 155 } 156 157 if ( !found ) 158 { 159 /* `loca' is the last table */ 160 dist = (FT_Long)stream->size - pos; 161 } 162 163 if ( new_loca_len <= (FT_ULong)dist ) 164 { 165 face->num_locations = (FT_ULong)face->root.num_glyphs + 1; 166 table_len = new_loca_len; 167 168 FT_TRACE2(( "adjusting num_locations to %d\n", 169 face->num_locations )); 170 } 171 else 172 { 173 face->root.num_glyphs = face->num_locations 174 ? (FT_Long)face->num_locations - 1 : 0; 175 176 FT_TRACE2(( "adjusting num_glyphs to %d\n", 177 face->root.num_glyphs )); 178 } 179 } 180 } 181 182 /* 183 * Extract the frame. We don't need to decompress it since 184 * we are able to parse it directly. 185 */ 186 if ( FT_FRAME_EXTRACT( table_len, face->glyph_locations ) ) 187 goto Exit; 188 189 FT_TRACE2(( "loaded\n" )); 190 191 Exit: 192 return error; 193 } 194 195 196 FT_LOCAL_DEF( FT_ULong ) tt_face_get_location(TT_Face face,FT_UInt gindex,FT_UInt * asize)197 tt_face_get_location( TT_Face face, 198 FT_UInt gindex, 199 FT_UInt *asize ) 200 { 201 FT_ULong pos1, pos2; 202 FT_Byte* p; 203 FT_Byte* p_limit; 204 205 206 pos1 = pos2 = 0; 207 208 if ( gindex < face->num_locations ) 209 { 210 if ( face->header.Index_To_Loc_Format != 0 ) 211 { 212 p = face->glyph_locations + gindex * 4; 213 p_limit = face->glyph_locations + face->num_locations * 4; 214 215 pos1 = FT_NEXT_ULONG( p ); 216 pos2 = pos1; 217 218 if ( p + 4 <= p_limit ) 219 pos2 = FT_NEXT_ULONG( p ); 220 } 221 else 222 { 223 p = face->glyph_locations + gindex * 2; 224 p_limit = face->glyph_locations + face->num_locations * 2; 225 226 pos1 = FT_NEXT_USHORT( p ); 227 pos2 = pos1; 228 229 if ( p + 2 <= p_limit ) 230 pos2 = FT_NEXT_USHORT( p ); 231 232 pos1 <<= 1; 233 pos2 <<= 1; 234 } 235 } 236 237 /* Check broken location data. */ 238 if ( pos1 > face->glyf_len ) 239 { 240 FT_TRACE1(( "tt_face_get_location:" 241 " too large offset (0x%08lx) found for glyph index %ld,\n" 242 " " 243 " exceeding the end of `glyf' table (0x%08lx)\n", 244 pos1, gindex, face->glyf_len )); 245 *asize = 0; 246 return 0; 247 } 248 249 if ( pos2 > face->glyf_len ) 250 { 251 /* We try to sanitize the last `loca' entry. */ 252 if ( gindex == face->num_locations - 2 ) 253 { 254 FT_TRACE1(( "tt_face_get_location:" 255 " too large size (%ld bytes) found for glyph index %ld,\n" 256 " " 257 " truncating at the end of `glyf' table to %ld bytes\n", 258 pos2 - pos1, gindex, face->glyf_len - pos1 )); 259 pos2 = face->glyf_len; 260 } 261 else 262 { 263 FT_TRACE1(( "tt_face_get_location:" 264 " too large offset (0x%08lx) found for glyph index %ld,\n" 265 " " 266 " exceeding the end of `glyf' table (0x%08lx)\n", 267 pos2, gindex + 1, face->glyf_len )); 268 *asize = 0; 269 return 0; 270 } 271 } 272 273 /* The `loca' table must be ordered; it refers to the length of */ 274 /* an entry as the difference between the current and the next */ 275 /* position. However, there do exist (malformed) fonts which */ 276 /* don't obey this rule, so we are only able to provide an */ 277 /* upper bound for the size. */ 278 /* */ 279 /* We get (intentionally) a wrong, non-zero result in case the */ 280 /* `glyf' table is missing. */ 281 if ( pos2 >= pos1 ) 282 *asize = (FT_UInt)( pos2 - pos1 ); 283 else 284 *asize = (FT_UInt)( face->glyf_len - pos1 ); 285 286 return pos1; 287 } 288 289 290 FT_LOCAL_DEF( void ) tt_face_done_loca(TT_Face face)291 tt_face_done_loca( TT_Face face ) 292 { 293 FT_Stream stream = face->root.stream; 294 295 296 FT_FRAME_RELEASE( face->glyph_locations ); 297 face->num_locations = 0; 298 } 299 300 301 302 /************************************************************************** 303 * 304 * @Function: 305 * tt_face_load_cvt 306 * 307 * @Description: 308 * Load the control value table into a face object. 309 * 310 * @InOut: 311 * face :: 312 * A handle to the target face object. 313 * 314 * @Input: 315 * stream :: 316 * A handle to the input stream. 317 * 318 * @Return: 319 * FreeType error code. 0 means success. 320 */ 321 FT_LOCAL_DEF( FT_Error ) tt_face_load_cvt(TT_Face face,FT_Stream stream)322 tt_face_load_cvt( TT_Face face, 323 FT_Stream stream ) 324 { 325 #ifdef TT_USE_BYTECODE_INTERPRETER 326 327 FT_Error error; 328 FT_Memory memory = stream->memory; 329 FT_ULong table_len; 330 331 332 FT_TRACE2(( "CVT " )); 333 334 error = face->goto_table( face, TTAG_cvt, stream, &table_len ); 335 if ( error ) 336 { 337 FT_TRACE2(( "is missing\n" )); 338 339 face->cvt_size = 0; 340 face->cvt = NULL; 341 error = FT_Err_Ok; 342 343 goto Exit; 344 } 345 346 face->cvt_size = table_len / 2; 347 348 if ( FT_NEW_ARRAY( face->cvt, face->cvt_size ) ) 349 goto Exit; 350 351 if ( FT_FRAME_ENTER( face->cvt_size * 2L ) ) 352 goto Exit; 353 354 { 355 FT_Short* cur = face->cvt; 356 FT_Short* limit = cur + face->cvt_size; 357 358 359 for ( ; cur < limit; cur++ ) 360 *cur = FT_GET_SHORT(); 361 } 362 363 FT_FRAME_EXIT(); 364 FT_TRACE2(( "loaded\n" )); 365 366 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT 367 if ( face->doblend ) 368 error = tt_face_vary_cvt( face, stream ); 369 #endif 370 371 Exit: 372 return error; 373 374 #else /* !TT_USE_BYTECODE_INTERPRETER */ 375 376 FT_UNUSED( face ); 377 FT_UNUSED( stream ); 378 379 return FT_Err_Ok; 380 381 #endif 382 } 383 384 385 /************************************************************************** 386 * 387 * @Function: 388 * tt_face_load_fpgm 389 * 390 * @Description: 391 * Load the font program. 392 * 393 * @InOut: 394 * face :: 395 * A handle to the target face object. 396 * 397 * @Input: 398 * stream :: 399 * A handle to the input stream. 400 * 401 * @Return: 402 * FreeType error code. 0 means success. 403 */ 404 FT_LOCAL_DEF( FT_Error ) tt_face_load_fpgm(TT_Face face,FT_Stream stream)405 tt_face_load_fpgm( TT_Face face, 406 FT_Stream stream ) 407 { 408 #ifdef TT_USE_BYTECODE_INTERPRETER 409 410 FT_Error error; 411 FT_ULong table_len; 412 413 414 FT_TRACE2(( "Font program " )); 415 416 /* The font program is optional */ 417 error = face->goto_table( face, TTAG_fpgm, stream, &table_len ); 418 if ( error ) 419 { 420 face->font_program = NULL; 421 face->font_program_size = 0; 422 error = FT_Err_Ok; 423 424 FT_TRACE2(( "is missing\n" )); 425 } 426 else 427 { 428 face->font_program_size = table_len; 429 if ( FT_FRAME_EXTRACT( table_len, face->font_program ) ) 430 goto Exit; 431 432 FT_TRACE2(( "loaded, %12d bytes\n", face->font_program_size )); 433 } 434 435 Exit: 436 return error; 437 438 #else /* !TT_USE_BYTECODE_INTERPRETER */ 439 440 FT_UNUSED( face ); 441 FT_UNUSED( stream ); 442 443 return FT_Err_Ok; 444 445 #endif 446 } 447 448 449 /************************************************************************** 450 * 451 * @Function: 452 * tt_face_load_prep 453 * 454 * @Description: 455 * Load the cvt program. 456 * 457 * @InOut: 458 * face :: 459 * A handle to the target face object. 460 * 461 * @Input: 462 * stream :: 463 * A handle to the input stream. 464 * 465 * @Return: 466 * FreeType error code. 0 means success. 467 */ 468 FT_LOCAL_DEF( FT_Error ) tt_face_load_prep(TT_Face face,FT_Stream stream)469 tt_face_load_prep( TT_Face face, 470 FT_Stream stream ) 471 { 472 #ifdef TT_USE_BYTECODE_INTERPRETER 473 474 FT_Error error; 475 FT_ULong table_len; 476 477 478 FT_TRACE2(( "Prep program " )); 479 480 error = face->goto_table( face, TTAG_prep, stream, &table_len ); 481 if ( error ) 482 { 483 face->cvt_program = NULL; 484 face->cvt_program_size = 0; 485 error = FT_Err_Ok; 486 487 FT_TRACE2(( "is missing\n" )); 488 } 489 else 490 { 491 face->cvt_program_size = table_len; 492 if ( FT_FRAME_EXTRACT( table_len, face->cvt_program ) ) 493 goto Exit; 494 495 FT_TRACE2(( "loaded, %12d bytes\n", face->cvt_program_size )); 496 } 497 498 Exit: 499 return error; 500 501 #else /* !TT_USE_BYTECODE_INTERPRETER */ 502 503 FT_UNUSED( face ); 504 FT_UNUSED( stream ); 505 506 return FT_Err_Ok; 507 508 #endif 509 } 510 511 512 /************************************************************************** 513 * 514 * @Function: 515 * tt_face_load_hdmx 516 * 517 * @Description: 518 * Load the `hdmx' table into the face object. 519 * 520 * @Input: 521 * face :: 522 * A handle to the target face object. 523 * 524 * stream :: 525 * A handle to the input stream. 526 * 527 * @Return: 528 * FreeType error code. 0 means success. 529 */ 530 531 FT_LOCAL_DEF( FT_Error ) tt_face_load_hdmx(TT_Face face,FT_Stream stream)532 tt_face_load_hdmx( TT_Face face, 533 FT_Stream stream ) 534 { 535 FT_Error error; 536 FT_Memory memory = stream->memory; 537 FT_UInt nn, num_records; 538 FT_ULong table_size, record_size; 539 FT_Byte* p; 540 FT_Byte* limit; 541 542 543 /* this table is optional */ 544 error = face->goto_table( face, TTAG_hdmx, stream, &table_size ); 545 if ( error || table_size < 8 ) 546 return FT_Err_Ok; 547 548 if ( FT_FRAME_EXTRACT( table_size, face->hdmx_table ) ) 549 goto Exit; 550 551 p = face->hdmx_table; 552 limit = p + table_size; 553 554 /* Given that `hdmx' tables are losing its importance (for example, */ 555 /* variation fonts introduced in OpenType 1.8 must not have this */ 556 /* table) we no longer test for a correct `version' field. */ 557 p += 2; 558 num_records = FT_NEXT_USHORT( p ); 559 record_size = FT_NEXT_ULONG( p ); 560 561 /* The maximum number of bytes in an hdmx device record is the */ 562 /* maximum number of glyphs + 2; this is 0xFFFF + 2, thus */ 563 /* explaining why `record_size' is a long (which we read as */ 564 /* unsigned long for convenience). In practice, two bytes are */ 565 /* sufficient to hold the size value. */ 566 /* */ 567 /* There are at least two fonts, HANNOM-A and HANNOM-B version */ 568 /* 2.0 (2005), which get this wrong: The upper two bytes of */ 569 /* the size value are set to 0xFF instead of 0x00. We catch */ 570 /* and fix this. */ 571 572 if ( record_size >= 0xFFFF0000UL ) 573 record_size &= 0xFFFFU; 574 575 /* The limit for `num_records' is a heuristic value. */ 576 if ( num_records > 255 || 577 ( num_records > 0 && 578 ( record_size > 0x10001L || 579 record_size < 4 ) ) ) 580 { 581 error = FT_THROW( Invalid_File_Format ); 582 goto Fail; 583 } 584 585 if ( FT_NEW_ARRAY( face->hdmx_record_sizes, num_records ) ) 586 goto Fail; 587 588 for ( nn = 0; nn < num_records; nn++ ) 589 { 590 if ( p + record_size > limit ) 591 break; 592 593 face->hdmx_record_sizes[nn] = p[0]; 594 p += record_size; 595 } 596 597 face->hdmx_record_count = nn; 598 face->hdmx_table_size = table_size; 599 face->hdmx_record_size = record_size; 600 601 Exit: 602 return error; 603 604 Fail: 605 FT_FRAME_RELEASE( face->hdmx_table ); 606 face->hdmx_table_size = 0; 607 goto Exit; 608 } 609 610 611 FT_LOCAL_DEF( void ) tt_face_free_hdmx(TT_Face face)612 tt_face_free_hdmx( TT_Face face ) 613 { 614 FT_Stream stream = face->root.stream; 615 FT_Memory memory = stream->memory; 616 617 618 FT_FREE( face->hdmx_record_sizes ); 619 FT_FRAME_RELEASE( face->hdmx_table ); 620 } 621 622 623 /************************************************************************** 624 * 625 * Return the advance width table for a given pixel size if it is found 626 * in the font's `hdmx' table (if any). 627 */ 628 FT_LOCAL_DEF( FT_Byte* ) tt_face_get_device_metrics(TT_Face face,FT_UInt ppem,FT_UInt gindex)629 tt_face_get_device_metrics( TT_Face face, 630 FT_UInt ppem, 631 FT_UInt gindex ) 632 { 633 FT_UInt nn; 634 FT_Byte* result = NULL; 635 FT_ULong record_size = face->hdmx_record_size; 636 FT_Byte* record = face->hdmx_table + 8; 637 638 639 for ( nn = 0; nn < face->hdmx_record_count; nn++ ) 640 if ( face->hdmx_record_sizes[nn] == ppem ) 641 { 642 gindex += 2; 643 if ( gindex < record_size ) 644 result = record + nn * record_size + gindex; 645 break; 646 } 647 648 return result; 649 } 650 651 652 /* END */ 653