1/****************************************************************************
2 *
3 * tttables.h
4 *
5 * Basic SFNT/TrueType tables definitions and interface
6 * (specification only).
7 *
8 * Copyright (C) 1996-2021 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
33FT_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 an OpenType variation font, 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 an OpenType variation font, 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 an OpenType variation font, 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 (1/20th points) */
428 FT_UShort usUpperOpticalPointSize; /* in twips (1/20th 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 an OpenType variation font, 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 * offset ::
709 * The starting offset in the table (or file if tag~==~0).
710 *
711 * @output:
712 * buffer ::
713 * The target buffer address. The client must ensure that the memory
714 * array is big enough to hold the data.
715 *
716 * @inout:
717 * length ::
718 * If the `length` parameter is `NULL`, try to load the whole table.
719 * Return an error code if it fails.
720 *
721 * Else, if `*length` is~0, exit immediately while returning the
722 * table's (or file) full size in it.
723 *
724 * Else the number of bytes to read from the table or file, from the
725 * starting offset.
726 *
727 * @return:
728 * FreeType error code. 0~means success.
729 *
730 * @note:
731 * If you need to determine the table's length you should first call this
732 * function with `*length` set to~0, as in the following example:
733 *
734 * ```
735 * FT_ULong length = 0;
736 *
737 *
738 * error = FT_Load_Sfnt_Table( face, tag, 0, NULL, &length );
739 * if ( error ) { ... table does not exist ... }
740 *
741 * buffer = malloc( length );
742 * if ( buffer == NULL ) { ... not enough memory ... }
743 *
744 * error = FT_Load_Sfnt_Table( face, tag, 0, buffer, &length );
745 * if ( error ) { ... could not load table ... }
746 * ```
747 *
748 * Note that structures like @TT_Header or @TT_OS2 can't be used with
749 * this function; they are limited to @FT_Get_Sfnt_Table. Reason is that
750 * those structures depend on the processor architecture, with varying
751 * size (e.g. 32bit vs. 64bit) or order (big endian vs. little endian).
752 *
753 */
754 FT_EXPORT( FT_Error )
755 FT_Load_Sfnt_Table( FT_Face face,
756 FT_ULong tag,
757 FT_Long offset,
758 FT_Byte* buffer,
759 FT_ULong* length );
760
761
762 /**************************************************************************
763 *
764 * @function:
765 * FT_Sfnt_Table_Info
766 *
767 * @description:
768 * Return information on an SFNT table.
769 *
770 * @input:
771 * face ::
772 * A handle to the source face.
773 *
774 * table_index ::
775 * The index of an SFNT table. The function returns
776 * FT_Err_Table_Missing for an invalid value.
777 *
778 * @inout:
779 * tag ::
780 * The name tag of the SFNT table. If the value is `NULL`,
781 * `table_index` is ignored, and `length` returns the number of SFNT
782 * tables in the font.
783 *
784 * @output:
785 * length ::
786 * The length of the SFNT table (or the number of SFNT tables,
787 * depending on `tag`).
788 *
789 * @return:
790 * FreeType error code. 0~means success.
791 *
792 * @note:
793 * While parsing fonts, FreeType handles SFNT tables with length zero as
794 * missing.
795 *
796 */
797 FT_EXPORT( FT_Error )
798 FT_Sfnt_Table_Info( FT_Face face,
799 FT_UInt table_index,
800 FT_ULong *tag,
801 FT_ULong *length );
802
803
804 /**************************************************************************
805 *
806 * @function:
807 * FT_Get_CMap_Language_ID
808 *
809 * @description:
810 * Return cmap language ID as specified in the OpenType standard.
811 * Definitions of language ID values are in file @FT_TRUETYPE_IDS_H.
812 *
813 * @input:
814 * charmap ::
815 * The target charmap.
816 *
817 * @return:
818 * The language ID of `charmap`. If `charmap` doesn't belong to an SFNT
819 * face, just return~0 as the default value.
820 *
821 * For a format~14 cmap (to access Unicode IVS), the return value is
822 * 0xFFFFFFFF.
823 */
824 FT_EXPORT( FT_ULong )
825 FT_Get_CMap_Language_ID( FT_CharMap charmap );
826
827
828 /**************************************************************************
829 *
830 * @function:
831 * FT_Get_CMap_Format
832 *
833 * @description:
834 * Return the format of an SFNT 'cmap' table.
835 *
836 * @input:
837 * charmap ::
838 * The target charmap.
839 *
840 * @return:
841 * The format of `charmap`. If `charmap` doesn't belong to an SFNT face,
842 * return -1.
843 */
844 FT_EXPORT( FT_Long )
845 FT_Get_CMap_Format( FT_CharMap charmap );
846
847 /* */
848
849
850FT_END_HEADER
851
852#endif /* TTTABLES_H_ */
853
854
855/* END */
856

source code of include/freetype2/freetype/tttables.h