include/freetype/tttables.h

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  tttables.h                                                             */
   4 /*                                                                         */
   5 /*    Basic SFNT/TrueType tables definitions and interface                 */
   6 /*    (specification only).                                                */
   7 /*                                                                         */
   8 /*  Copyright 1996-2000 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
  27 #ifdef __cplusplus
  28   extern "C" {
  29 #endif
  30
  31
  32   /*************************************************************************/
  33   /*                                                                       */
  34   /* <Struct>                                                              */
  35   /*    TT_Header                                                          */
  36   /*                                                                       */
  37   /* <Description>                                                         */
  38   /*    A structure used to model a TrueType font header table.  All       */
  39   /*    fields follow the TrueType specification.                          */
  40   /*                                                                       */
  41   typedef struct  TT_Header_
  42   {
  43     FT_Fixed   Table_Version;
  44     FT_Fixed   Font_Revision;
  45
  46     FT_Long    CheckSum_Adjust;
  47     FT_Long    Magic_Number;
  48
  49     FT_UShort  Flags;
  50     FT_UShort  Units_Per_EM;
  51
  52     FT_Long    Created [2];
  53     FT_Long    Modified[2];
  54
  55     FT_Short   xMin;
  56     FT_Short   yMin;
  57     FT_Short   xMax;
  58     FT_Short   yMax;
  59
  60     FT_UShort  Mac_Style;
  61     FT_UShort  Lowest_Rec_PPEM;
  62
  63     FT_Short   Font_Direction;
  64     FT_Short   Index_To_Loc_Format;
  65     FT_Short   Glyph_Data_Format;
  66
  67   } TT_Header;
  68
  69
  70   /*************************************************************************/
  71   /*                                                                       */
  72   /* <Struct>                                                              */
  73   /*    TT_HoriHeader                                                      */
  74   /*                                                                       */
  75   /* <Description>                                                         */
  76   /*    A structure used to model a TrueType horizontal header, the `hhea' */
  77   /*    table, as well as the corresponding horizontal metrics table,      */
  78   /*    i.e., the `hmtx' table.                                            */
  79   /*                                                                       */
  80   /* <Fields>                                                              */
  81   /*    Version                :: The table version.                       */
  82   /*                                                                       */
  83   /*    Ascender               :: The font's ascender, i.e., the distance  */
  84   /*                              from the baseline to the top-most of all */
  85   /*                              glyph points found in the font.          */
  86   /*                                                                       */
  87   /*                              This value is invalid in many fonts, as  */
  88   /*                              it is usually set by the font designer,  */
  89   /*                              and often reflects only a portion of the */
  90   /*                              glyphs found in the font (maybe ASCII).  */
  91   /*                                                                       */
  92   /*                              You should use the `sTypoAscender' field */
  93   /*                              of the OS/2 table instead if you want    */
  94   /*                              the correct one.                         */
  95   /*                                                                       */
  96   /*    Descender              :: The font's descender, i.e., the distance */
  97   /*                              from the baseline to the bottom-most of  */
  98   /*                              all glyph points found in the font.  It  */
  99   /*                              is negative.                             */
 100   /*                                                                       */
 101   /*                              This value is invalid in many fonts, as  */
 102   /*                              it is usually set by the font designer,  */
 103   /*                              and often reflects only a portion of the */
 104   /*                              glyphs found in the font (maybe ASCII).  */
 105   /*                                                                       */
 106   /*                              You should use the `sTypoDescender'      */
 107   /*                              field of the OS/2 table instead if you   */
 108   /*                              want the correct one.                    */
 109   /*                                                                       */
 110   /*    Line_Gap               :: The font's line gap, i.e., the distance  */
 111   /*                              to add to the ascender and descender to  */
 112   /*                              get the BTB, i.e., the                   */
 113   /*                              baseline-to-baseline distance for the    */
 114   /*                              font.                                    */
 115   /*                                                                       */
 116   /*    advance_Width_Max      :: This field is the maximum of all advance */
 117   /*                              widths found in the font.  It can be     */
 118   /*                              used to compute the maximum width of an  */
 119   /*                              arbitrary string of text.                */
 120   /*                                                                       */
 121   /*    min_Left_Side_Bearing  :: The minimum left side bearing of all     */
 122   /*                              glyphs within the font.                  */
 123   /*                                                                       */
 124   /*    min_Right_Side_Bearing :: The minimum right side bearing of all    */
 125   /*                              glyphs within the font.                  */
 126   /*                                                                       */
 127   /*    xMax_Extent            :: The maximum horizontal extent (i.e., the */
 128   /*                              `width' of a glyph's bounding box) for   */
 129   /*                              all glyphs in the font.                  */
 130   /*                                                                       */
 131   /*    caret_Slope_Rise       :: The rise coefficient of the cursor's     */
 132   /*                              slope of the cursor (slope=rise/run).    */
 133   /*                                                                       */
 134   /*    caret_Slope_Run        :: The run coefficient of the cursor's      */
 135   /*                              slope.                                   */
 136   /*                                                                       */
 137   /*    Reserved               :: 10 reserved bytes.                       */
 138   /*                                                                       */
 139   /*    metric_Data_Format     :: Always 0.                                */
 140   /*                                                                       */
 141   /*    number_Of_HMetrics     :: Number of HMetrics entries in the `hmtx' */
 142   /*                              table -- this value can be smaller than  */
 143   /*                              the total number of glyphs in the font.  */
 144   /*                                                                       */
 145   /*    long_metrics           :: A pointer into the `hmtx' table.         */
 146   /*                                                                       */
 147   /*    short_metrics          :: A pointer into the `hmtx' table.         */
 148   /*                                                                       */
 149   /* <Note>                                                                */
 150   /*    IMPORTANT: The TT_HoriHeader and TT_VertHeader structures should   */
 151   /*               be identical except for the names of their fields which */
 152   /*               are different.                                          */
 153   /*                                                                       */
 154   /*               This ensures that a single function in the `ttload'     */
 155   /*               module is able to read both the horizontal and vertical */
 156   /*               headers.                                                */
 157   /*                                                                       */
 158   typedef struct  TT_HoriHeader_
 159   {
 160     FT_Fixed   Version;
 161     FT_Short   Ascender;
 162     FT_Short   Descender;
 163     FT_Short   Line_Gap;
 164
 165     FT_UShort  advance_Width_Max;      /* advance width maximum */
 166
 167     FT_Short   min_Left_Side_Bearing;  /* minimum left-sb       */
 168     FT_Short   min_Right_Side_Bearing; /* minimum right-sb      */
 169     FT_Short   xMax_Extent;            /* xmax extents          */
 170     FT_Short   caret_Slope_Rise;
 171     FT_Short   caret_Slope_Run;
 172     FT_Short   caret_Offset;
 173
 174     FT_Short   Reserved[4];
 175
 176     FT_Short   metric_Data_Format;
 177     FT_UShort  number_Of_HMetrics;
 178
 179     /* The following fields are not defined by the TrueType specification */
 180     /* but they're used to connect the metrics header to the relevant     */
 181     /* `HMTX' table.                                                      */
 182
 183     void*      long_metrics;
 184     void*      short_metrics;
 185
 186   } TT_HoriHeader;
 187
 188
 189   /*************************************************************************/
 190   /*                                                                       */
 191   /* <Struct>                                                              */
 192   /*    TT_VertHeader                                                      */
 193   /*                                                                       */
 194   /* <Description>                                                         */
 195   /*    A structure used to model a TrueType vertical header, the `vhea'   */
 196   /*    table, as well as the corresponding vertical metrics table, i.e.,  */
 197   /*    the `vmtx' table.                                                  */
 198   /*                                                                       */
 199   /* <Fields>                                                              */
 200   /*    Version                 :: The table version.                      */
 201   /*                                                                       */
 202   /*    Ascender                :: The font's ascender, i.e., the distance */
 203   /*                               from the baseline to the top-most of    */
 204   /*                               all glyph points found in the font.     */
 205   /*                                                                       */
 206   /*                               This value is invalid in many fonts, as */
 207   /*                               it is usually set by the font designer, */
 208   /*                               and often reflects only a portion of    */
 209   /*                               the glyphs found in the font (maybe     */
 210   /*                               ASCII).                                 */
 211   /*                                                                       */
 212   /*                               You should use the `sTypoAscender'      */
 213   /*                               field of the OS/2 table instead if you  */
 214   /*                               want the correct one.                   */
 215   /*                                                                       */
 216   /*    Descender               :: The font's descender, i.e., the         */
 217   /*                               distance from the baseline to the       */
 218   /*                               bottom-most of all glyph points found   */
 219   /*                               in the font.  It is negative.           */
 220   /*                                                                       */
 221   /*                               This value is invalid in many fonts, as */
 222   /*                               it is usually set by the font designer, */
 223   /*                               and often reflects only a portion of    */
 224   /*                               the glyphs found in the font (maybe     */
 225   /*                               ASCII).                                 */
 226   /*                                                                       */
 227   /*                               You should use the `sTypoDescender'     */
 228   /*                               field of the OS/2 table instead if you  */
 229   /*                               want the correct one.                   */
 230   /*                                                                       */
 231   /*    Line_Gap                :: The font's line gap, i.e., the distance */
 232   /*                               to add to the ascender and descender to */
 233   /*                               get the BTB, i.e., the                  */
 234   /*                               baseline-to-baseline distance for the   */
 235   /*                               font.                                   */
 236   /*                                                                       */
 237   /*    advance_Height_Max      :: This field is the maximum of all        */
 238   /*                               advance heights found in the font.  It  */
 239   /*                               can be used to compute the maximum      */
 240   /*                               height of an arbitrary string of text.  */
 241   /*                                                                       */
 242   /*    min_Top_Side_Bearing    :: The minimum top side bearing of all     */
 243   /*                               glyphs within the font.                 */
 244   /*                                                                       */
 245   /*    min_Bottom_Side_Bearing :: The minimum bottom side bearing of all  */
 246   /*                               glyphs within the font.                 */
 247   /*                                                                       */
 248   /*    yMax_Extent             :: The maximum vertical extent (i.e., the  */
 249   /*                               `height' of a glyph's bounding box) for */
 250   /*                               all glyphs in the font.                 */
 251   /*                                                                       */
 252   /*    caret_Slope_Rise        :: The rise coefficient of the cursor's    */
 253   /*                               slope of the cursor (slope=rise/run).   */
 254   /*                                                                       */
 255   /*    caret_Slope_Run         :: The run coefficient of the cursor's     */
 256   /*                               slope.                                  */
 257   /*                                                                       */
 258   /*    Reserved                :: 10 reserved bytes.                      */
 259   /*                                                                       */
 260   /*    metric_Data_Format      :: Always 0.                               */
 261   /*                                                                       */
 262   /*    number_Of_HMetrics      :: Number of VMetrics entries in the       */
 263   /*                               `vmtx' table -- this value can be       */
 264   /*                               smaller than the total number of glyphs */
 265   /*                               in the font.                            */
 266   /*                                                                       */
 267   /*    long_metrics           :: A pointer into the `vmtx' table.         */
 268   /*                                                                       */
 269   /*    short_metrics          :: A pointer into the `vmtx' table.         */
 270   /*                                                                       */
 271   /* <Note>                                                                */
 272   /*    IMPORTANT: The TT_HoriHeader and TT_VertHeader structures should   */
 273   /*               be identical except for the names of their fields which */
 274   /*               are different.                                          */
 275   /*                                                                       */
 276   /*               This ensures that a single function in the `ttload'     */
 277   /*               module is able to read both the horizontal and vertical */
 278   /*               headers.                                                */
 279   /*                                                                       */
 280   typedef struct TT_VertHeader_
 281   {
 282     FT_Fixed   Version;
 283     FT_Short   Ascender;
 284     FT_Short   Descender;
 285     FT_Short   Line_Gap;
 286
 287     FT_UShort  advance_Height_Max;      /* advance height maximum */
 288
 289     FT_Short   min_Top_Side_Bearing;    /* minimum left-sb or top-sb       */
 290     FT_Short   min_Bottom_Side_Bearing; /* minimum right-sb or bottom-sb   */
 291     FT_Short   yMax_Extent;             /* xmax or ymax extents            */
 292     FT_Short   caret_Slope_Rise;
 293     FT_Short   caret_Slope_Run;
 294     FT_Short   caret_Offset;
 295
 296     FT_Short   Reserved[4];
 297
 298     FT_Short   metric_Data_Format;
 299     FT_UShort  number_Of_VMetrics;
 300
 301     /* The following fields are not defined by the TrueType specification */
 302     /* but they're used to connect the metrics header to the relevant     */
 303     /* `HMTX' or `VMTX' table.                                            */
 304
 305     void*      long_metrics;
 306     void*      short_metrics;
 307
 308   } TT_VertHeader;
 309
 310
 311   /*************************************************************************/
 312   /*                                                                       */
 313   /* <Struct>                                                              */
 314   /*    TT_OS2                                                             */
 315   /*                                                                       */
 316   /* <Description>                                                         */
 317   /*    A structure used to model a TrueType OS/2 table. This is the long  */
 318   /*    table version.  All fields comply to the TrueType specification.   */
 319   /*                                                                       */
 320   /*    Note that we now support old Mac fonts which do not include an     */
 321   /*    OS/2 table.  In this case, the `version' field is always set to    */
 322   /*    0xFFFF.                                                            */
 323   /*                                                                       */
 324   typedef struct  TT_OS2_
 325   {
 326     FT_UShort  version;                /* 0x0001 - more or 0xFFFF */
 327     FT_Short   xAvgCharWidth;
 328     FT_UShort  usWeightClass;
 329     FT_UShort  usWidthClass;
 330     FT_Short   fsType;
 331     FT_Short   ySubscriptXSize;
 332     FT_Short   ySubscriptYSize;
 333     FT_Short   ySubscriptXOffset;
 334     FT_Short   ySubscriptYOffset;
 335     FT_Short   ySuperscriptXSize;
 336     FT_Short   ySuperscriptYSize;
 337     FT_Short   ySuperscriptXOffset;
 338     FT_Short   ySuperscriptYOffset;
 339     FT_Short   yStrikeoutSize;
 340     FT_Short   yStrikeoutPosition;
 341     FT_Short   sFamilyClass;
 342
 343     FT_Byte    panose[10];
 344
 345     FT_ULong   ulUnicodeRange1;        /* Bits 0-31   */
 346     FT_ULong   ulUnicodeRange2;        /* Bits 32-63  */
 347     FT_ULong   ulUnicodeRange3;        /* Bits 64-95  */
 348     FT_ULong   ulUnicodeRange4;        /* Bits 96-127 */
 349
 350     FT_Char    achVendID[4];
 351
 352     FT_UShort  fsSelection;
 353     FT_UShort  usFirstCharIndex;
 354     FT_UShort  usLastCharIndex;
 355     FT_Short   sTypoAscender;
 356     FT_Short   sTypoDescender;
 357     FT_Short   sTypoLineGap;
 358     FT_UShort  usWinAscent;
 359     FT_UShort  usWinDescent;
 360
 361     /* only version 1 tables: */
 362
 363     FT_ULong   ulCodePageRange1;       /* Bits 0-31   */
 364     FT_ULong   ulCodePageRange2;       /* Bits 32-63  */
 365
 366     /* only version 2 tables: */
 367
 368     FT_Short   sxHeight;
 369     FT_Short   sCapHeight;
 370     FT_UShort  usDefaultChar;
 371     FT_UShort  usBreakChar;
 372     FT_UShort  usMaxContext;
 373
 374   } TT_OS2;
 375
 376
 377   /*************************************************************************/
 378   /*                                                                       */
 379   /* <Struct>                                                              */
 380   /*    TT_Postscript                                                      */
 381   /*                                                                       */
 382   /* <Description>                                                         */
 383   /*    A structure used to model a TrueType Postscript table.  All fields */
 384   /*    comply to the TrueType table.  This structure does not reference   */
 385   /*    the Postscript glyph names, which can be nevertheless accessed     */
 386   /*    with the `ttpost' module.                                          */
 387   /*                                                                       */
 388   typedef struct  TT_Postscript_
 389   {
 390     FT_Fixed  FormatType;
 391     FT_Fixed  italicAngle;
 392     FT_Short  underlinePosition;
 393     FT_Short  underlineThickness;
 394     FT_ULong  isFixedPitch;
 395     FT_ULong  minMemType42;
 396     FT_ULong  maxMemType42;
 397     FT_ULong  minMemType1;
 398     FT_ULong  maxMemType1;
 399
 400     /* Glyph names follow in the file, but we don't   */
 401     /* load them by default.  See the ttpost.c file.  */
 402
 403   } TT_Postscript;
 404
 405
 406   /*************************************************************************/
 407   /*                                                                       */
 408   /* <Struct>                                                              */
 409   /*    TT_PCLT                                                            */
 410   /*                                                                       */
 411   /* <Description>                                                         */
 412   /*    A structure used to model a TrueType PCLT table.  All fields       */
 413   /*    comply to the TrueType table.                                      */
 414   /*                                                                       */
 415   typedef struct TT_PCLT_
 416   {
 417     FT_Fixed   Version;
 418     FT_ULong   FontNumber;
 419     FT_UShort  Pitch;
 420     FT_UShort  xHeight;
 421     FT_UShort  Style;
 422     FT_UShort  TypeFamily;
 423     FT_UShort  CapHeight;
 424     FT_UShort  SymbolSet;
 425     FT_Char    TypeFace[16];
 426     FT_Char    CharacterComplement[8];
 427     FT_Char    FileName[6];
 428     FT_Char    StrokeWeight;
 429     FT_Char    WidthType;
 430     FT_Byte    SerifStyle;
 431     FT_Byte    Reserved;
 432
 433   } TT_PCLT;
 434
 435
 436   /*************************************************************************/
 437   /*                                                                       */
 438   /* <Struct>                                                              */
 439   /*    TT_MaxProfile                                                      */
 440   /*                                                                       */
 441   /* <Description>                                                         */
 442   /*    The maximum profile is a table containing many max values which    */
 443   /*    can be used to pre-allocate arrays.  This ensures that no memory   */
 444   /*    allocation occurs during a glyph load.                             */
 445   /*                                                                       */
 446   /* <Fields>                                                              */
 447   /*    version               :: The version number.                       */
 448   /*                                                                       */
 449   /*    numGlyphs             :: The number of glyphs in this TrueType     */
 450   /*                             font.                                     */
 451   /*                                                                       */
 452   /*    maxPoints             :: The maximum number of points in a         */
 453   /*                             non-composite TrueType glyph.  See also   */
 454   /*                             the structure element                     */
 455   /*                             `maxCompositePoints'.                     */
 456   /*                                                                       */
 457   /*    maxContours           :: The maximum number of contours in a       */
 458   /*                             non-composite TrueType glyph.  See also   */
 459   /*                             the structure element                     */
 460   /*                             `maxCompositeContours'.                   */
 461   /*                                                                       */
 462   /*    maxCompositePoints    :: The maximum number of points in a         */
 463   /*                             composite TrueType glyph.  See also the   */
 464   /*                             structure element `maxPoints'.            */
 465   /*                                                                       */
 466   /*    maxCompositeContours  :: The maximum number of contours in a       */
 467   /*                             composite TrueType glyph.  See also the   */
 468   /*                             structure element `maxContours'.          */
 469   /*                                                                       */
 470   /*    maxZones              :: The maximum number of zones used for      */
 471   /*                             glyph hinting.                            */
 472   /*                                                                       */
 473   /*    maxTwilightPoints     :: The maximum number of points in the       */
 474   /*                             twilight zone used for glyph hinting.     */
 475   /*                                                                       */
 476   /*    maxStorage            :: The maximum number of elements in the     */
 477   /*                             storage area used for glyph hinting.      */
 478   /*                                                                       */
 479   /*    maxFunctionDefs       :: The maximum number of function            */
 480   /*                             definitions in the TrueType bytecode for  */
 481   /*                             this font.                                */
 482   /*                                                                       */
 483   /*    maxInstructionDefs    :: The maximum number of instruction         */
 484   /*                             definitions in the TrueType bytecode for  */
 485   /*                             this font.                                */
 486   /*                                                                       */
 487   /*    maxStackElements      :: The maximum number of stack elements used */
 488   /*                             during bytecode interpretation.           */
 489   /*                                                                       */
 490   /*    maxSizeOfInstructions :: The maximum number of TrueType opcodes    */
 491   /*                             used for glyph hinting.                   */
 492   /*                                                                       */
 493   /*    maxComponentElements  :: An obscure value related to composite     */
 494   /*                             glyphs definitions.                       */
 495   /*                                                                       */
 496   /*    maxComponentDepth     :: An obscure value related to composite     */
 497   /*                             glyphs definitions.  Probably the maximum */
 498   /*                             number of simple glyphs in a composite.   */
 499   /*                                                                       */
 500   /* <Note>                                                                */
 501   /*    This structure is only used during font loading.                   */
 502   /*                                                                       */
 503   typedef struct  TT_MaxProfile_
 504   {
 505     FT_Fixed   version;
 506     FT_UShort  numGlyphs;
 507     FT_UShort  maxPoints;
 508     FT_UShort  maxContours;
 509     FT_UShort  maxCompositePoints;
 510     FT_UShort  maxCompositeContours;
 511     FT_UShort  maxZones;
 512     FT_UShort  maxTwilightPoints;
 513     FT_UShort  maxStorage;
 514     FT_UShort  maxFunctionDefs;
 515     FT_UShort  maxInstructionDefs;
 516     FT_UShort  maxStackElements;
 517     FT_UShort  maxSizeOfInstructions;
 518     FT_UShort  maxComponentElements;
 519     FT_UShort  maxComponentDepth;
 520
 521   } TT_MaxProfile;
 522
 523
 524   typedef enum
 525   {
 526     ft_sfnt_head = 0,
 527     ft_sfnt_maxp = 1,
 528     ft_sfnt_os2  = 2,
 529     ft_sfnt_hhea = 3,
 530     ft_sfnt_vhea = 4,
 531     ft_sfnt_post = 5,
 532     ft_sfnt_pclt = 6,
 533
 534     sfnt_max   /* don't remove */
 535
 536   } FT_Sfnt_Tag;
 537
 538
 539   /* internal use only */
 540   typedef void*  (*FT_Get_Sfnt_Table_Func)( FT_Face      face,
 541                                             FT_Sfnt_Tag  tag );
 542
 543
 544   /*************************************************************************/
 545   /*                                                                       */
 546   /* <Function>                                                            */
 547   /*    FT_Get_Sfnt_Table                                                  */
 548   /*                                                                       */
 549   /* <Description>                                                         */
 550   /*    Returns a pointer to a given SFNT table within a face.             */
 551   /*                                                                       */
 552   /* <Input>                                                               */
 553   /*    face :: A handle to the source.                                    */
 554   /*                                                                       */
 555   /*    tag  :: The index of the SFNT table.                               */
 556   /*                                                                       */
 557   /* <Return>                                                              */
 558   /*    A type-less pointer to the table.  This will be 0 in case of       */
 559   /*    error, or if the corresponding table was not found *OR* loaded     */
 560   /*    from the file.                                                     */
 561   /*                                                                       */
 562   /* <Note>                                                                */
 563   /*    The table is owned by the face object and disappears with it.      */
 564   /*                                                                       */
 565   /*    This function is only useful to access SFNT tables that are loaded */
 566   /*    by the sfnt/truetype/opentype drivers.  See FT_Sfnt_tag for a      */
 567   /*    list.                                                              */
 568   /*                                                                       */
 569   /*    You can load any table using the (internal) SFNT_Interface         */
 570   /*    structure -- this is available via FT_Get_Module_Interface().      */
 571   /*                                                                       */
 572   FT_EXPORT_DEF( void* )  FT_Get_Sfnt_Table( FT_Face      face,
 573                                              FT_Sfnt_Tag  tag );
 574
 575 #ifdef __cplusplus
 576   }
 577 #endif
 578
 579
 580 #endif /* TTTABLES_H */
 581
 582
 583 /* END */