tttables.h (25422B)
1 /**************************************************************************** 2 * 3 * tttables.h 4 * 5 * Basic SFNT/TrueType tables definitions and interface 6 * (specification only). 7 * 8 * Copyright (C) 1996-2025 by 9 * David Turner, Robert Wilhelm, and Werner Lemberg. 10 * 11 * This file is part of the FreeType project, and may only be used, 12 * modified, and distributed under the terms of the FreeType project 13 * license, LICENSE.TXT. By continuing to use, modify, or distribute 14 * this file you indicate that you have read the license and 15 * understand and accept it fully. 16 * 17 */ 18 19 20 #ifndef TTTABLES_H_ 21 #define TTTABLES_H_ 22 23 24 #include <freetype/freetype.h> 25 26 #ifdef FREETYPE_H 27 #error "freetype.h of FreeType 1 has been loaded!" 28 #error "Please fix the directory search order for header files" 29 #error "so that freetype.h of FreeType 2 is found first." 30 #endif 31 32 33 FT_BEGIN_HEADER 34 35 /************************************************************************** 36 * 37 * @section: 38 * truetype_tables 39 * 40 * @title: 41 * TrueType Tables 42 * 43 * @abstract: 44 * TrueType-specific table types and functions. 45 * 46 * @description: 47 * This section contains definitions of some basic tables specific to 48 * TrueType and OpenType as well as some routines used to access and 49 * process them. 50 * 51 * @order: 52 * TT_Header 53 * TT_HoriHeader 54 * TT_VertHeader 55 * TT_OS2 56 * TT_Postscript 57 * TT_PCLT 58 * TT_MaxProfile 59 * 60 * FT_Sfnt_Tag 61 * FT_Get_Sfnt_Table 62 * FT_Load_Sfnt_Table 63 * FT_Sfnt_Table_Info 64 * 65 * FT_Get_CMap_Language_ID 66 * FT_Get_CMap_Format 67 * 68 * FT_PARAM_TAG_UNPATENTED_HINTING 69 * 70 */ 71 72 73 /************************************************************************** 74 * 75 * @struct: 76 * TT_Header 77 * 78 * @description: 79 * A structure to model a TrueType font header table. All fields follow 80 * the OpenType specification. The 64-bit timestamps are stored in 81 * two-element arrays `Created` and `Modified`, first the upper then 82 * the lower 32~bits. 83 */ 84 typedef struct TT_Header_ 85 { 86 FT_Fixed Table_Version; 87 FT_Fixed Font_Revision; 88 89 FT_Long CheckSum_Adjust; 90 FT_Long Magic_Number; 91 92 FT_UShort Flags; 93 FT_UShort Units_Per_EM; 94 95 FT_ULong Created [2]; 96 FT_ULong Modified[2]; 97 98 FT_Short xMin; 99 FT_Short yMin; 100 FT_Short xMax; 101 FT_Short yMax; 102 103 FT_UShort Mac_Style; 104 FT_UShort Lowest_Rec_PPEM; 105 106 FT_Short Font_Direction; 107 FT_Short Index_To_Loc_Format; 108 FT_Short Glyph_Data_Format; 109 110 } TT_Header; 111 112 113 /************************************************************************** 114 * 115 * @struct: 116 * TT_HoriHeader 117 * 118 * @description: 119 * A structure to model a TrueType horizontal header, the 'hhea' table, 120 * as well as the corresponding horizontal metrics table, 'hmtx'. 121 * 122 * @fields: 123 * Version :: 124 * The table version. 125 * 126 * Ascender :: 127 * The font's ascender, i.e., the distance from the baseline to the 128 * top-most of all glyph points found in the font. 129 * 130 * This value is invalid in many fonts, as it is usually set by the 131 * font designer, and often reflects only a portion of the glyphs found 132 * in the font (maybe ASCII). 133 * 134 * You should use the `sTypoAscender` field of the 'OS/2' table instead 135 * if you want the correct one. 136 * 137 * Descender :: 138 * The font's descender, i.e., the distance from the baseline to the 139 * bottom-most of all glyph points found in the font. It is negative. 140 * 141 * This value is invalid in many fonts, as it is usually set by the 142 * font designer, and often reflects only a portion of the glyphs found 143 * in the font (maybe ASCII). 144 * 145 * You should use the `sTypoDescender` field of the 'OS/2' table 146 * instead if you want the correct one. 147 * 148 * Line_Gap :: 149 * The font's line gap, i.e., the distance to add to the ascender and 150 * descender to get the BTB, i.e., the baseline-to-baseline distance 151 * for the font. 152 * 153 * advance_Width_Max :: 154 * This field is the maximum of all advance widths found in the font. 155 * It can be used to compute the maximum width of an arbitrary string 156 * of text. 157 * 158 * min_Left_Side_Bearing :: 159 * The minimum left side bearing of all glyphs within the font. 160 * 161 * min_Right_Side_Bearing :: 162 * The minimum right side bearing of all glyphs within the font. 163 * 164 * xMax_Extent :: 165 * The maximum horizontal extent (i.e., the 'width' of a glyph's 166 * bounding box) for all glyphs in the font. 167 * 168 * caret_Slope_Rise :: 169 * The rise coefficient of the cursor's slope of the cursor 170 * (slope=rise/run). 171 * 172 * caret_Slope_Run :: 173 * The run coefficient of the cursor's slope. 174 * 175 * caret_Offset :: 176 * The cursor's offset for slanted fonts. 177 * 178 * Reserved :: 179 * 8~reserved bytes. 180 * 181 * metric_Data_Format :: 182 * Always~0. 183 * 184 * number_Of_HMetrics :: 185 * Number of HMetrics entries in the 'hmtx' table -- this value can be 186 * smaller than the total number of glyphs in the font. 187 * 188 * long_metrics :: 189 * A pointer into the 'hmtx' table. 190 * 191 * short_metrics :: 192 * A pointer into the 'hmtx' table. 193 * 194 * @note: 195 * For OpenType Font Variations, the values of the following fields can 196 * change after a call to @FT_Set_Var_Design_Coordinates (and friends) if 197 * the font contains an 'MVAR' table: `caret_Slope_Rise`, 198 * `caret_Slope_Run`, and `caret_Offset`. 199 */ 200 typedef struct TT_HoriHeader_ 201 { 202 FT_Fixed Version; 203 FT_Short Ascender; 204 FT_Short Descender; 205 FT_Short Line_Gap; 206 207 FT_UShort advance_Width_Max; /* advance width maximum */ 208 209 FT_Short min_Left_Side_Bearing; /* minimum left-sb */ 210 FT_Short min_Right_Side_Bearing; /* minimum right-sb */ 211 FT_Short xMax_Extent; /* xmax extents */ 212 FT_Short caret_Slope_Rise; 213 FT_Short caret_Slope_Run; 214 FT_Short caret_Offset; 215 216 FT_Short Reserved[4]; 217 218 FT_Short metric_Data_Format; 219 FT_UShort number_Of_HMetrics; 220 221 /* The following fields are not defined by the OpenType specification */ 222 /* but they are used to connect the metrics header to the relevant */ 223 /* 'hmtx' table. */ 224 225 void* long_metrics; 226 void* short_metrics; 227 228 } TT_HoriHeader; 229 230 231 /************************************************************************** 232 * 233 * @struct: 234 * TT_VertHeader 235 * 236 * @description: 237 * A structure used to model a TrueType vertical header, the 'vhea' 238 * table, as well as the corresponding vertical metrics table, 'vmtx'. 239 * 240 * @fields: 241 * Version :: 242 * The table version. 243 * 244 * Ascender :: 245 * The font's ascender, i.e., the distance from the baseline to the 246 * top-most of all glyph points found in the font. 247 * 248 * This value is invalid in many fonts, as it is usually set by the 249 * font designer, and often reflects only a portion of the glyphs found 250 * in the font (maybe ASCII). 251 * 252 * You should use the `sTypoAscender` field of the 'OS/2' table instead 253 * if you want the correct one. 254 * 255 * Descender :: 256 * The font's descender, i.e., the distance from the baseline to the 257 * bottom-most of all glyph points found in the font. It is negative. 258 * 259 * This value is invalid in many fonts, as it is usually set by the 260 * font designer, and often reflects only a portion of the glyphs found 261 * in the font (maybe ASCII). 262 * 263 * You should use the `sTypoDescender` field of the 'OS/2' table 264 * instead if you want the correct one. 265 * 266 * Line_Gap :: 267 * The font's line gap, i.e., the distance to add to the ascender and 268 * descender to get the BTB, i.e., the baseline-to-baseline distance 269 * for the font. 270 * 271 * advance_Height_Max :: 272 * This field is the maximum of all advance heights found in the font. 273 * It can be used to compute the maximum height of an arbitrary string 274 * of text. 275 * 276 * min_Top_Side_Bearing :: 277 * The minimum top side bearing of all glyphs within the font. 278 * 279 * min_Bottom_Side_Bearing :: 280 * The minimum bottom side bearing of all glyphs within the font. 281 * 282 * yMax_Extent :: 283 * The maximum vertical extent (i.e., the 'height' of a glyph's 284 * bounding box) for all glyphs in the font. 285 * 286 * caret_Slope_Rise :: 287 * The rise coefficient of the cursor's slope of the cursor 288 * (slope=rise/run). 289 * 290 * caret_Slope_Run :: 291 * The run coefficient of the cursor's slope. 292 * 293 * caret_Offset :: 294 * The cursor's offset for slanted fonts. 295 * 296 * Reserved :: 297 * 8~reserved bytes. 298 * 299 * metric_Data_Format :: 300 * Always~0. 301 * 302 * number_Of_VMetrics :: 303 * Number of VMetrics entries in the 'vmtx' table -- this value can be 304 * smaller than the total number of glyphs in the font. 305 * 306 * long_metrics :: 307 * A pointer into the 'vmtx' table. 308 * 309 * short_metrics :: 310 * A pointer into the 'vmtx' table. 311 * 312 * @note: 313 * For OpenType Font Variations, the values of the following fields can 314 * change after a call to @FT_Set_Var_Design_Coordinates (and friends) if 315 * the font contains an 'MVAR' table: `Ascender`, `Descender`, 316 * `Line_Gap`, `caret_Slope_Rise`, `caret_Slope_Run`, and `caret_Offset`. 317 */ 318 typedef struct TT_VertHeader_ 319 { 320 FT_Fixed Version; 321 FT_Short Ascender; 322 FT_Short Descender; 323 FT_Short Line_Gap; 324 325 FT_UShort advance_Height_Max; /* advance height maximum */ 326 327 FT_Short min_Top_Side_Bearing; /* minimum top-sb */ 328 FT_Short min_Bottom_Side_Bearing; /* minimum bottom-sb */ 329 FT_Short yMax_Extent; /* ymax extents */ 330 FT_Short caret_Slope_Rise; 331 FT_Short caret_Slope_Run; 332 FT_Short caret_Offset; 333 334 FT_Short Reserved[4]; 335 336 FT_Short metric_Data_Format; 337 FT_UShort number_Of_VMetrics; 338 339 /* The following fields are not defined by the OpenType specification */ 340 /* but they are used to connect the metrics header to the relevant */ 341 /* 'vmtx' table. */ 342 343 void* long_metrics; 344 void* short_metrics; 345 346 } TT_VertHeader; 347 348 349 /************************************************************************** 350 * 351 * @struct: 352 * TT_OS2 353 * 354 * @description: 355 * A structure to model a TrueType 'OS/2' table. All fields comply to 356 * the OpenType specification. 357 * 358 * Note that we now support old Mac fonts that do not include an 'OS/2' 359 * table. In this case, the `version` field is always set to 0xFFFF. 360 * 361 * @note: 362 * For OpenType Font Variations, the values of the following fields can 363 * change after a call to @FT_Set_Var_Design_Coordinates (and friends) if 364 * the font contains an 'MVAR' table: `sCapHeight`, `sTypoAscender`, 365 * `sTypoDescender`, `sTypoLineGap`, `sxHeight`, `usWinAscent`, 366 * `usWinDescent`, `yStrikeoutPosition`, `yStrikeoutSize`, 367 * `ySubscriptXOffset`, `ySubScriptXSize`, `ySubscriptYOffset`, 368 * `ySubscriptYSize`, `ySuperscriptXOffset`, `ySuperscriptXSize`, 369 * `ySuperscriptYOffset`, and `ySuperscriptYSize`. 370 * 371 * Possible values for bits in the `ulUnicodeRangeX` fields are given by 372 * the @TT_UCR_XXX macros. 373 */ 374 375 typedef struct TT_OS2_ 376 { 377 FT_UShort version; /* 0x0001 - more or 0xFFFF */ 378 FT_Short xAvgCharWidth; 379 FT_UShort usWeightClass; 380 FT_UShort usWidthClass; 381 FT_UShort fsType; 382 FT_Short ySubscriptXSize; 383 FT_Short ySubscriptYSize; 384 FT_Short ySubscriptXOffset; 385 FT_Short ySubscriptYOffset; 386 FT_Short ySuperscriptXSize; 387 FT_Short ySuperscriptYSize; 388 FT_Short ySuperscriptXOffset; 389 FT_Short ySuperscriptYOffset; 390 FT_Short yStrikeoutSize; 391 FT_Short yStrikeoutPosition; 392 FT_Short sFamilyClass; 393 394 FT_Byte panose[10]; 395 396 FT_ULong ulUnicodeRange1; /* Bits 0-31 */ 397 FT_ULong ulUnicodeRange2; /* Bits 32-63 */ 398 FT_ULong ulUnicodeRange3; /* Bits 64-95 */ 399 FT_ULong ulUnicodeRange4; /* Bits 96-127 */ 400 401 FT_Char achVendID[4]; 402 403 FT_UShort fsSelection; 404 FT_UShort usFirstCharIndex; 405 FT_UShort usLastCharIndex; 406 FT_Short sTypoAscender; 407 FT_Short sTypoDescender; 408 FT_Short sTypoLineGap; 409 FT_UShort usWinAscent; 410 FT_UShort usWinDescent; 411 412 /* only version 1 and higher: */ 413 414 FT_ULong ulCodePageRange1; /* Bits 0-31 */ 415 FT_ULong ulCodePageRange2; /* Bits 32-63 */ 416 417 /* only version 2 and higher: */ 418 419 FT_Short sxHeight; 420 FT_Short sCapHeight; 421 FT_UShort usDefaultChar; 422 FT_UShort usBreakChar; 423 FT_UShort usMaxContext; 424 425 /* only version 5 and higher: */ 426 427 FT_UShort usLowerOpticalPointSize; /* in twips (1/20 points) */ 428 FT_UShort usUpperOpticalPointSize; /* in twips (1/20 points) */ 429 430 } TT_OS2; 431 432 433 /************************************************************************** 434 * 435 * @struct: 436 * TT_Postscript 437 * 438 * @description: 439 * A structure to model a TrueType 'post' table. All fields comply to 440 * the OpenType specification. This structure does not reference a 441 * font's PostScript glyph names; use @FT_Get_Glyph_Name to retrieve 442 * them. 443 * 444 * @note: 445 * For OpenType Font Variations, the values of the following fields can 446 * change after a call to @FT_Set_Var_Design_Coordinates (and friends) if 447 * the font contains an 'MVAR' table: `underlinePosition` and 448 * `underlineThickness`. 449 */ 450 typedef struct TT_Postscript_ 451 { 452 FT_Fixed FormatType; 453 FT_Fixed italicAngle; 454 FT_Short underlinePosition; 455 FT_Short underlineThickness; 456 FT_ULong isFixedPitch; 457 FT_ULong minMemType42; 458 FT_ULong maxMemType42; 459 FT_ULong minMemType1; 460 FT_ULong maxMemType1; 461 462 /* Glyph names follow in the 'post' table, but we don't */ 463 /* load them by default. */ 464 465 } TT_Postscript; 466 467 468 /************************************************************************** 469 * 470 * @struct: 471 * TT_PCLT 472 * 473 * @description: 474 * A structure to model a TrueType 'PCLT' table. All fields comply to 475 * the OpenType specification. 476 */ 477 typedef struct TT_PCLT_ 478 { 479 FT_Fixed Version; 480 FT_ULong FontNumber; 481 FT_UShort Pitch; 482 FT_UShort xHeight; 483 FT_UShort Style; 484 FT_UShort TypeFamily; 485 FT_UShort CapHeight; 486 FT_UShort SymbolSet; 487 FT_Char TypeFace[16]; 488 FT_Char CharacterComplement[8]; 489 FT_Char FileName[6]; 490 FT_Char StrokeWeight; 491 FT_Char WidthType; 492 FT_Byte SerifStyle; 493 FT_Byte Reserved; 494 495 } TT_PCLT; 496 497 498 /************************************************************************** 499 * 500 * @struct: 501 * TT_MaxProfile 502 * 503 * @description: 504 * The maximum profile ('maxp') table contains many max values, which can 505 * be used to pre-allocate arrays for speeding up glyph loading and 506 * hinting. 507 * 508 * @fields: 509 * version :: 510 * The version number. 511 * 512 * numGlyphs :: 513 * The number of glyphs in this TrueType font. 514 * 515 * maxPoints :: 516 * The maximum number of points in a non-composite TrueType glyph. See 517 * also `maxCompositePoints`. 518 * 519 * maxContours :: 520 * The maximum number of contours in a non-composite TrueType glyph. 521 * See also `maxCompositeContours`. 522 * 523 * maxCompositePoints :: 524 * The maximum number of points in a composite TrueType glyph. See 525 * also `maxPoints`. 526 * 527 * maxCompositeContours :: 528 * The maximum number of contours in a composite TrueType glyph. See 529 * also `maxContours`. 530 * 531 * maxZones :: 532 * The maximum number of zones used for glyph hinting. 533 * 534 * maxTwilightPoints :: 535 * The maximum number of points in the twilight zone used for glyph 536 * hinting. 537 * 538 * maxStorage :: 539 * The maximum number of elements in the storage area used for glyph 540 * hinting. 541 * 542 * maxFunctionDefs :: 543 * The maximum number of function definitions in the TrueType bytecode 544 * for this font. 545 * 546 * maxInstructionDefs :: 547 * The maximum number of instruction definitions in the TrueType 548 * bytecode for this font. 549 * 550 * maxStackElements :: 551 * The maximum number of stack elements used during bytecode 552 * interpretation. 553 * 554 * maxSizeOfInstructions :: 555 * The maximum number of TrueType opcodes used for glyph hinting. 556 * 557 * maxComponentElements :: 558 * The maximum number of simple (i.e., non-composite) glyphs in a 559 * composite glyph. 560 * 561 * maxComponentDepth :: 562 * The maximum nesting depth of composite glyphs. 563 * 564 * @note: 565 * This structure is only used during font loading. 566 */ 567 typedef struct TT_MaxProfile_ 568 { 569 FT_Fixed version; 570 FT_UShort numGlyphs; 571 FT_UShort maxPoints; 572 FT_UShort maxContours; 573 FT_UShort maxCompositePoints; 574 FT_UShort maxCompositeContours; 575 FT_UShort maxZones; 576 FT_UShort maxTwilightPoints; 577 FT_UShort maxStorage; 578 FT_UShort maxFunctionDefs; 579 FT_UShort maxInstructionDefs; 580 FT_UShort maxStackElements; 581 FT_UShort maxSizeOfInstructions; 582 FT_UShort maxComponentElements; 583 FT_UShort maxComponentDepth; 584 585 } TT_MaxProfile; 586 587 588 /************************************************************************** 589 * 590 * @enum: 591 * FT_Sfnt_Tag 592 * 593 * @description: 594 * An enumeration to specify indices of SFNT tables loaded and parsed by 595 * FreeType during initialization of an SFNT font. Used in the 596 * @FT_Get_Sfnt_Table API function. 597 * 598 * @values: 599 * FT_SFNT_HEAD :: 600 * To access the font's @TT_Header structure. 601 * 602 * FT_SFNT_MAXP :: 603 * To access the font's @TT_MaxProfile structure. 604 * 605 * FT_SFNT_OS2 :: 606 * To access the font's @TT_OS2 structure. 607 * 608 * FT_SFNT_HHEA :: 609 * To access the font's @TT_HoriHeader structure. 610 * 611 * FT_SFNT_VHEA :: 612 * To access the font's @TT_VertHeader structure. 613 * 614 * FT_SFNT_POST :: 615 * To access the font's @TT_Postscript structure. 616 * 617 * FT_SFNT_PCLT :: 618 * To access the font's @TT_PCLT structure. 619 */ 620 typedef enum FT_Sfnt_Tag_ 621 { 622 FT_SFNT_HEAD, 623 FT_SFNT_MAXP, 624 FT_SFNT_OS2, 625 FT_SFNT_HHEA, 626 FT_SFNT_VHEA, 627 FT_SFNT_POST, 628 FT_SFNT_PCLT, 629 630 FT_SFNT_MAX 631 632 } FT_Sfnt_Tag; 633 634 /* these constants are deprecated; use the corresponding `FT_Sfnt_Tag` */ 635 /* values instead */ 636 #define ft_sfnt_head FT_SFNT_HEAD 637 #define ft_sfnt_maxp FT_SFNT_MAXP 638 #define ft_sfnt_os2 FT_SFNT_OS2 639 #define ft_sfnt_hhea FT_SFNT_HHEA 640 #define ft_sfnt_vhea FT_SFNT_VHEA 641 #define ft_sfnt_post FT_SFNT_POST 642 #define ft_sfnt_pclt FT_SFNT_PCLT 643 644 645 /************************************************************************** 646 * 647 * @function: 648 * FT_Get_Sfnt_Table 649 * 650 * @description: 651 * Return a pointer to a given SFNT table stored within a face. 652 * 653 * @input: 654 * face :: 655 * A handle to the source. 656 * 657 * tag :: 658 * The index of the SFNT table. 659 * 660 * @return: 661 * A type-less pointer to the table. This will be `NULL` in case of 662 * error, or if the corresponding table was not found **OR** loaded from 663 * the file. 664 * 665 * Use a typecast according to `tag` to access the structure elements. 666 * 667 * @note: 668 * The table is owned by the face object and disappears with it. 669 * 670 * This function is only useful to access SFNT tables that are loaded by 671 * the sfnt, truetype, and opentype drivers. See @FT_Sfnt_Tag for a 672 * list. 673 * 674 * @example: 675 * Here is an example demonstrating access to the 'vhea' table. 676 * 677 * ``` 678 * TT_VertHeader* vert_header; 679 * 680 * 681 * vert_header = 682 * (TT_VertHeader*)FT_Get_Sfnt_Table( face, FT_SFNT_VHEA ); 683 * ``` 684 */ 685 FT_EXPORT( void* ) 686 FT_Get_Sfnt_Table( FT_Face face, 687 FT_Sfnt_Tag tag ); 688 689 690 /************************************************************************** 691 * 692 * @function: 693 * FT_Load_Sfnt_Table 694 * 695 * @description: 696 * Load any SFNT font table into client memory. 697 * 698 * @input: 699 * face :: 700 * A handle to the source face. 701 * 702 * tag :: 703 * The four-byte tag of the table to load. Use value~0 if you want to 704 * access the whole font file. Otherwise, you can use one of the 705 * definitions found in the @FT_TRUETYPE_TAGS_H file, or forge a new 706 * one with @FT_MAKE_TAG. 707 * 708 * [Since 2.14] Use value~1 if you want to access the table directory 709 * of the (currently selected) font. 710 * 711 * offset :: 712 * The starting offset in the table (or file if tag~==~0). 713 * 714 * @output: 715 * buffer :: 716 * The target buffer address. The client must ensure that the memory 717 * array is big enough to hold the data. 718 * 719 * @inout: 720 * length :: 721 * If the `length` parameter is `NULL`, try to load the whole table. 722 * Return an error code if it fails. 723 * 724 * Else, if `*length` is~0, exit immediately while returning the 725 * table's (or file) full size in it. 726 * 727 * Else the number of bytes to read from the table or file, from the 728 * starting offset. 729 * 730 * @return: 731 * FreeType error code. 0~means success. 732 * 733 * @note: 734 * If you need to determine the table's length you should first call this 735 * function with `*length` set to~0, as in the following example: 736 * 737 * ``` 738 * FT_ULong length = 0; 739 * 740 * 741 * error = FT_Load_Sfnt_Table( face, tag, 0, NULL, &length ); 742 * if ( error ) { ... table does not exist ... } 743 * 744 * buffer = malloc( length ); 745 * if ( buffer == NULL ) { ... not enough memory ... } 746 * 747 * error = FT_Load_Sfnt_Table( face, tag, 0, buffer, &length ); 748 * if ( error ) { ... could not load table ... } 749 * ``` 750 * 751 * Note that structures like @TT_Header or @TT_OS2 can't be used with 752 * this function; they are limited to @FT_Get_Sfnt_Table. Reason is that 753 * those structures depend on the processor architecture, with varying 754 * size (e.g. 32bit vs. 64bit) or order (big endian vs. little endian). 755 * 756 */ 757 FT_EXPORT( FT_Error ) 758 FT_Load_Sfnt_Table( FT_Face face, 759 FT_ULong tag, 760 FT_Long offset, 761 FT_Byte* buffer, 762 FT_ULong* length ); 763 764 765 /************************************************************************** 766 * 767 * @function: 768 * FT_Sfnt_Table_Info 769 * 770 * @description: 771 * Return information on an SFNT table. 772 * 773 * @input: 774 * face :: 775 * A handle to the source face. 776 * 777 * table_index :: 778 * The index of an SFNT table. The function returns 779 * FT_Err_Table_Missing for an invalid value. 780 * 781 * @inout: 782 * tag :: 783 * The name tag of the SFNT table. If the value is `NULL`, 784 * `table_index` is ignored, and `length` returns the number of SFNT 785 * tables in the font. 786 * 787 * @output: 788 * length :: 789 * The length of the SFNT table (or the number of SFNT tables, 790 * depending on `tag`). 791 * 792 * @return: 793 * FreeType error code. 0~means success. 794 * 795 * @note: 796 * While parsing fonts, FreeType handles SFNT tables with length zero as 797 * missing. 798 * 799 */ 800 FT_EXPORT( FT_Error ) 801 FT_Sfnt_Table_Info( FT_Face face, 802 FT_UInt table_index, 803 FT_ULong *tag, 804 FT_ULong *length ); 805 806 807 /************************************************************************** 808 * 809 * @function: 810 * FT_Get_CMap_Language_ID 811 * 812 * @description: 813 * Return cmap language ID as specified in the OpenType standard. 814 * Definitions of language ID values are in file @FT_TRUETYPE_IDS_H. 815 * 816 * @input: 817 * charmap :: 818 * The target charmap. 819 * 820 * @return: 821 * The language ID of `charmap`. If `charmap` doesn't belong to an SFNT 822 * face, just return~0 as the default value. 823 * 824 * For a format~14 cmap (to access Unicode IVS), the return value is 825 * 0xFFFFFFFF. 826 */ 827 FT_EXPORT( FT_ULong ) 828 FT_Get_CMap_Language_ID( FT_CharMap charmap ); 829 830 831 /************************************************************************** 832 * 833 * @function: 834 * FT_Get_CMap_Format 835 * 836 * @description: 837 * Return the format of an SFNT 'cmap' table. 838 * 839 * @input: 840 * charmap :: 841 * The target charmap. 842 * 843 * @return: 844 * The format of `charmap`. If `charmap` doesn't belong to an SFNT face 845 * (including the synthetic Unicode charmap sometimes created by 846 * FreeType), return -1. 847 */ 848 FT_EXPORT( FT_Long ) 849 FT_Get_CMap_Format( FT_CharMap charmap ); 850 851 /* */ 852 853 854 FT_END_HEADER 855 856 #endif /* TTTABLES_H_ */ 857 858 859 /* END */