freetype.h

神龙卡开发原代码

  struct  TT_Horizontal_Header_
  {
    TT_Fixed   Version;
    TT_FWord   Ascender;
    TT_FWord   Descender;
    TT_FWord   Line_Gap;

    TT_UFWord  advance_Width_Max;      /* advance width maximum */

    TT_FWord   min_Left_Side_Bearing;  /* minimum left-sb       */
    TT_FWord   min_Right_Side_Bearing; /* minimum right-sb      */
    TT_FWord   xMax_Extent;            /* xmax extents          */
    TT_FWord   caret_Slope_Rise;
    TT_FWord   caret_Slope_Run;

    TT_Short   Reserved0,
               Reserved1,
               Reserved2,
               Reserved3,
               Reserved4;

    TT_Short   metric_Data_Format;
    TT_UShort  number_Of_HMetrics;

    /* The following fields are not defined by the TrueType specification */
    /* but they're used to connect the metrics header to the relevant     */
    /* `HMTX' or `VMTX' table.                                            */

    void*      long_metrics;
    void*      short_metrics;
  };

  typedef struct TT_Horizontal_Header_  TT_Horizontal_Header;


  /*******************************************************/
  /*  This structure is the one defined by the TrueType  */
  /*  specification.  Note that it has exactly the same  */
  /*  layout as the horizontal header (both are loaded   */
  /*  by the same function).                             */

  struct  TT_Vertical_Header_
  {
    TT_Fixed   Version;
    TT_FWord   Ascender;
    TT_FWord   Descender;
    TT_FWord   Line_Gap;

    TT_UFWord  advance_Height_Max;      /* advance height maximum */

    TT_FWord   min_Top_Side_Bearing;    /* minimum left-sb or top-sb       */
    TT_FWord   min_Bottom_Side_Bearing; /* minimum right-sb or bottom-sb   */
    TT_FWord   yMax_Extent;             /* xmax or ymax extents            */
    TT_FWord   caret_Slope_Rise;
    TT_FWord   caret_Slope_Run;
    TT_FWord   caret_Offset;

    TT_Short   Reserved1,
               Reserved2,
               Reserved3,
               Reserved4;

    TT_Short   metric_Data_Format;
    TT_UShort  number_Of_VMetrics;

    /* The following fields are not defined by the TrueType specification */
    /* but they're used to connect the metrics header to the relevant     */
    /* `HMTX' or `VMTX' table.                                            */

    void*      long_metrics;
    void*      short_metrics;
  };

  typedef struct TT_Vertical_Header_  TT_Vertical_Header;


  /* ------ The OS/2 table ------ */

  /************************************************************************/
  /* Note that since FreeType 1.3, we support Mac fonts which do not have */
  /* an OS/2 table.  In this case the `version' field will be set to      */
  /* 0xFFFF by the table loader; all other fields should be 0.            */

  struct  TT_OS2_
  {
    TT_UShort  version;                /* 0x0001 */
    TT_FWord   xAvgCharWidth;
    TT_UShort  usWeightClass;
    TT_UShort  usWidthClass;
    TT_Short   fsType;
    TT_FWord   ySubscriptXSize;
    TT_FWord   ySubscriptYSize;
    TT_FWord   ySubscriptXOffset;
    TT_FWord   ySubscriptYOffset;
    TT_FWord   ySuperscriptXSize;
    TT_FWord   ySuperscriptYSize;
    TT_FWord   ySuperscriptXOffset;
    TT_FWord   ySuperscriptYOffset;
    TT_FWord   yStrikeoutSize;
    TT_FWord   yStrikeoutPosition;
    TT_Short   sFamilyClass;

    TT_Byte    panose[10];

    TT_ULong   ulUnicodeRange1;        /* Bits 0-31   */
    TT_ULong   ulUnicodeRange2;        /* Bits 32-63  */
    TT_ULong   ulUnicodeRange3;        /* Bits 64-95  */
    TT_ULong   ulUnicodeRange4;        /* Bits 96-127 */

    TT_Char    achVendID[4];

    TT_UShort  fsSelection;
    TT_UShort  usFirstCharIndex;
    TT_UShort  usLastCharIndex;
    TT_Short   sTypoAscender;
    TT_Short   sTypoDescender;
    TT_Short   sTypoLineGap;
    TT_UShort  usWinAscent;
    TT_UShort  usWinDescent;

    /* only version 1 tables: */

    TT_ULong   ulCodePageRange1;       /* Bits 0-31   */
    TT_ULong   ulCodePageRange2;       /* Bits 32-63  */
  };

  typedef struct TT_OS2_  TT_OS2;


  /* ------ The PostScript table ------ */

  struct  TT_Postscript_
  {
    TT_Fixed  FormatType;
    TT_Fixed  italicAngle;
    TT_FWord  underlinePosition;
    TT_FWord  underlineThickness;
    TT_ULong  isFixedPitch;
    TT_ULong  minMemType42;
    TT_ULong  maxMemType42;
    TT_ULong  minMemType1;
    TT_ULong  maxMemType1;

    /* Glyph names follow in the file, but we don't         */
    /* load them by default.  See the ftxpost.c extension.  */
  };

  typedef struct TT_Postscript_  TT_Postscript;


  /* ------ The horizontal device metrics table (`hdmx') ------ */

  struct  TT_Hdmx_Record_
  {
    TT_Byte   ppem;
    TT_Byte   max_width;
    TT_Byte*  widths;
  };

  typedef struct TT_Hdmx_Record_  TT_Hdmx_Record;


  struct  TT_Hdmx_
  {
    TT_UShort        version;
    TT_Short         num_records;
    TT_Hdmx_Record*  records;
  };

  typedef struct TT_Hdmx_  TT_Hdmx;


  /* A structure used to describe face properties. */

  struct  TT_Face_Properties_
  {
    TT_UShort  num_Glyphs;      /* number of glyphs in face              */
    TT_UShort  max_Points;      /* maximum number of points in a glyph   */
    TT_UShort  max_Contours;    /* maximum number of contours in a glyph */

    TT_UShort  num_CharMaps;    /* number of charmaps in the face     */
    TT_UShort  num_Names;       /* number of name records in the face */

    TT_ULong   num_Faces;  /* 1 for normal TrueType files, and the  */
                           /* number of embedded faces for TrueType */
                           /* collections                           */

    TT_Header*             header;        /* TrueType header table          */
    TT_Horizontal_Header*  horizontal;    /* TrueType horizontal header     */
    TT_OS2*                os2;           /* TrueType OS/2 table            */
    TT_Postscript*         postscript;    /* TrueType Postscript table      */
    TT_Hdmx*               hdmx;          /* TrueType hor. dev. metr. table */
    TT_Vertical_Header*    vertical;      /* TT Vertical header, if present */
  };

  typedef struct TT_Face_Properties_  TT_Face_Properties;


  /* Here are the definitions of the handle types used for FreeType's */
  /* most common objects accessed by the client application.  We use  */
  /* a simple trick:                                                  */
  /*                                                                  */
  /*   Each handle type is a structure that only contains one         */
  /*   pointer.  The advantage of structures is that they are         */
  /*   mutually exclusive types.  We could have defined the           */
  /*   following types:                                               */
  /*                                                                  */
  /*     typedef void*  TT_Stream;                                    */
  /*     typedef void*  TT_Face;                                      */
  /*     typedef void*  TT_Instance;                                  */
  /*     typedef void*  TT_Glyph;                                     */
  /*     typedef void*  TT_CharMap;                                   */
  /*                                                                  */
  /*   but these would have allowed lines like:                       */
  /*                                                                  */
  /*      stream = instance;                                          */
  /*                                                                  */
  /*   in the client code this would be a severe bug, unnoticed       */
  /*   by the compiler!                                               */
  /*                                                                  */
  /*   Thus, we enforce type checking with a simple language          */
  /*   trick...                                                       */
  /*                                                                  */
  /*   NOTE:  Some macros are defined in tttypes.h to perform         */
  /*          automatic type conversions for library hackers...       */

  struct TT_Engine_   { void*  z; };
  struct TT_Stream_   { void*  z; };
  struct TT_Face_     { void*  z; };
  struct TT_Instance_ { void*  z; };
  struct TT_Glyph_    { void*  z; };
  struct TT_CharMap_  { void*  z; };

  typedef struct TT_Engine_    TT_Engine;    /* engine instance           */
  typedef struct TT_Stream_    TT_Stream;    /* stream handle type        */
  typedef struct TT_Face_      TT_Face;      /* face handle type          */
  typedef struct TT_Instance_  TT_Instance;  /* instance handle type      */
  typedef struct TT_Glyph_     TT_Glyph;     /* glyph handle type         */
  typedef struct TT_CharMap_   TT_CharMap;   /* character map handle type */


  /* Almost all functions return an error code of this type. */

  typedef long  TT_Error;


  /*******************************************************************/
  /*                                                                 */
  /*  FreeType API                                                   */
  /*                                                                 */
  /*  All these begin with a `TT_' prefix.                           */
  /*                                                                 */
  /*  Most of them are implemented in the `ttapi.c' source file.     */
  /*                                                                 */
  /*******************************************************************/

  /* Get version information. */

  EXPORT_DEF
  TT_Error  TT_FreeType_Version( int  *major,
                                 int  *minor );


  /* Initialize the engine. */

  EXPORT_DEF
  TT_Error  TT_Init_FreeType( TT_Engine*  engine );


  /* Finalize the engine, and release all allocated objects. */

  EXPORT_DEF
  TT_Error  TT_Done_FreeType( TT_Engine  engine );


  /* Set the gray level palette.  This is an array of 5 bytes used */
  /* to produce the font smoothed pixmaps.  By convention:         */
  /*                                                               */
  /*  palette[0] = background (white)                              */
  /*  palette[1] = light                                           */
  /*  palette[2] = medium                                          */
  /*  palette[3] = dark                                            */
  /*  palette[4] = foreground (black)                              */
  /*                                                               */

  EXPORT_DEF
  TT_Error  TT_Set_Raster_Gray_Palette( TT_Engine  engine,
                                        TT_Byte*   palette );


  /* ----------------------- face management ----------------------- */

  /* Open a new TrueType font file, and returns a handle for  */
  /* it in variable '*face'.                                  */
  /*                                                          */
  /* Note: The file can be either a TrueType file (*.ttf) or  */
  /*       a TrueType collection (*.ttc, in this case, only   */
  /*       the first face is opened).  The number of faces in */
  /*       the same collection can be obtained in the face's  */
  /*       properties, using TT_Get_Face_Properties() and the */
  /*       `max_Faces' field.                                 */

  EXPORT_DEF
  TT_Error  TT_Open_Face( TT_Engine       engine,
                          const TT_Text*  fontPathName,
                          TT_Face*        face );


  /* Open a TrueType font file located inside a collection. */
  /* The font is assigned by its index in `fontIndex'.      */

  EXPORT_DEF
  TT_Error  TT_Open_Collection( TT_Engine       engine,
                                const TT_Text*  collectionPathName,
                                TT_ULong        fontIndex,
                                TT_Face*        face );


  /* Return face properties in the `properties' structure.          */
  /*                                                                */
  /* Note that since version 1.3, we support font files with no     */
  /* OS/2 table (mainly old Mac fonts).  In this case, the OS/2     */
  /* `version' field will be set to 0xFFFF, and all other fields    */
  /* will be zeroed.                                                */

  EXPORT_DEF
  TT_Error  TT_Get_Face_Properties( TT_Face              face,
                                    TT_Face_Properties*  properties );


  /* Set a face object's generic pointer */

  EXPORT_DEF
  TT_Error  TT_Set_Face_Pointer( TT_Face  face,
                                 void*    data );


  /* Get a face object's generic pointer */

  EXPORT_DEF
  void*  TT_Get_Face_Pointer( TT_Face  face );


  /* Close a face's file handle to save system resources.  The file */
  /* will be re-opened automatically on the next disk access.       */

  EXPORT_DEF
  TT_Error  TT_Flush_Face( TT_Face  face );

  /* Get a face's glyph metrics expressed in font units.  Returns any    */
  /* number of arrays.  Set the fields to NULL if you are not interested */
  /* by a given array.                                                   */

  EXPORT_DEF
  TT_Error  TT_Get_Face_Metrics( TT_Face     face,
                                 TT_UShort   firstGlyph,
                                 TT_UShort   lastGlyph,
                                 TT_Short*   leftBearings,
                                 TT_UShort*  widths,
                                 TT_Short*   topBearings,
                                 TT_UShort*  heights );


  /* Close a given font object, destroying all associated */
  /* instances.                                           */

  EXPORT_DEF
  TT_Error  TT_Close_Face( TT_Face  face );


  /* Get font or table data. */

  EXPORT_DEF
  TT_Error  TT_Get_Font_Data( TT_Face   face,
                              TT_ULong  tag,
                              TT_Long   offset,
                              void*     buffer,
                              TT_Long*  length );


/* A simple macro to build table tags from ASCII chars */

#define MAKE_TT_TAG( _x1, _x2, _x3, _x4 ) \