ttobjs.h

winNT技术操作系统,国外开放的原代码和LIUX一样

  /*  record).                                                             */
  /*                                                                       */
  /* The CVT is a one-dimensional array containing values that control     */
  /* certain important characteristics in a font, like the height of all   */
  /* capitals, all lowercase letter, default spacing or stem width/height. */
  /*                                                                       */
  /* These values are found in FUnits in the font file, and must be scaled */
  /* to pixel coordinates before being used by the CVT and glyph programs. */
  /* Unfortunately, when using distinct x and y resolutions (or distinct x */
  /* and y pointsizes), there are two possible scalings.                   */
  /*                                                                       */
  /* A first try was to implement a `lazy' scheme where all values were    */
  /* scaled when first used.  However, while some values are always used   */
  /* in the same direction, some others are used under many different      */
  /* circumstances and orientations.                                       */
  /*                                                                       */
  /* I have found a simpler way to do the same, and it even seems to work  */
  /* in most of the cases:                                                 */
  /*                                                                       */
  /* - All CVT values are scaled to the maximum ppem size.                 */
  /*                                                                       */
  /* - When performing a read or write in the CVT, a ratio factor is used  */
  /*   to perform adequate scaling.  Example:                              */
  /*                                                                       */
  /*     x_ppem = 14                                                       */
  /*     y_ppem = 10                                                       */
  /*                                                                       */
  /*   We choose ppem = x_ppem = 14 as the CVT scaling size.  All cvt      */
  /*   entries are scaled to it.                                           */
  /*                                                                       */
  /*     x_ratio = 1.0                                                     */
  /*     y_ratio = y_ppem/ppem (< 1.0)                                     */
  /*                                                                       */
  /*   We compute the current ratio like:                                  */
  /*                                                                       */
  /*   - If projVector is horizontal,                                      */
  /*       ratio = x_ratio = 1.0                                           */
  /*                                                                       */
  /*   - if projVector is vertical,                                        */
  /*       ratio = y_ratio                                                 */
  /*                                                                       */
  /*   - else,                                                             */
  /*       ratio = sqrt( (proj.x * x_ratio) ^ 2 + (proj.y * y_ratio) ^ 2 ) */
  /*                                                                       */
  /*   Reading a cvt value returns                                         */
  /*     ratio * cvt[index]                                                */
  /*                                                                       */
  /*   Writing a cvt value in pixels:                                      */
  /*     cvt[index] / ratio                                                */
  /*                                                                       */
  /*   The current ppem is simply                                          */
  /*     ratio * ppem                                                      */
  /*                                                                       */
  /*************************************************************************/


  /*************************************************************************/
  /*                                                                       */
  /* Metrics used by the TrueType size and context objects.                */
  /*                                                                       */
  typedef struct  TT_Size_Metrics_
  {
    /* for non-square pixels */
    FT_Long     x_ratio;
    FT_Long     y_ratio;

    FT_UShort   ppem;               /* maximum ppem size              */
    FT_Long     ratio;              /* current ratio                  */
    FT_Fixed    scale;

    FT_F26Dot6  compensations[4];   /* device-specific compensations  */

    FT_Bool     valid;

    FT_Bool     rotated;            /* `is the glyph rotated?'-flag   */
    FT_Bool     stretched;          /* `is the glyph stretched?'-flag */

  } TT_Size_Metrics;


  /*************************************************************************/
  /*                                                                       */
  /* TrueType size class.                                                  */
  /*                                                                       */
  typedef struct  TT_SizeRec_
  {
    FT_SizeRec         root;

    /* we have our own copy of metrics so that we can modify */
    /* it without affecting auto-hinting (when used)         */
    FT_Size_Metrics    metrics;

    TT_Size_Metrics    ttmetrics;

    FT_ULong           strike_index;      /* 0xFFFFFFFF to indicate invalid */

#ifdef TT_USE_BYTECODE_INTERPRETER

    FT_UInt            num_function_defs; /* number of function definitions */
    FT_UInt            max_function_defs;
    TT_DefArray        function_defs;     /* table of function definitions  */

    FT_UInt            num_instruction_defs;  /* number of ins. definitions */
    FT_UInt            max_instruction_defs;
    TT_DefArray        instruction_defs;      /* table of ins. definitions  */

    FT_UInt            max_func;
    FT_UInt            max_ins;

    TT_CodeRangeTable  codeRangeTable;

    TT_GraphicsState   GS;

    FT_ULong           cvt_size;      /* the scaled control value table */
    FT_Long*           cvt;

    FT_UShort          storage_size; /* The storage area is now part of */
    FT_Long*           storage;      /* the instance                    */

    TT_GlyphZoneRec    twilight;     /* The instance's twilight zone    */

    /* debugging variables */

    /* When using the debugger, we must keep the */
    /* execution context tied to the instance    */
    /* object rather than asking it on demand.   */

    FT_Bool            debug;
    TT_ExecContext     context;

    FT_Bool            bytecode_ready;
    FT_Bool            cvt_ready;

#endif /* TT_USE_BYTECODE_INTERPRETER */

  } TT_SizeRec;


  /*************************************************************************/
  /*                                                                       */
  /* TrueType driver class.                                                */
  /*                                                                       */
  typedef struct  TT_DriverRec_
  {
    FT_DriverRec     root;
    TT_ExecContext   context;  /* execution context        */
    TT_GlyphZoneRec  zone;     /* glyph loader points zone */

    void*            extension_component;

  } TT_DriverRec;


  /* Note: All of the functions below (except tt_size_reset()) are used    */
  /* as function pointers in a FT_Driver_ClassRec.  Therefore their        */
  /* parameters are of types FT_Face, FT_Size, etc., rather than TT_Face,  */
  /* TT_Size, etc., so that the compiler can confirm that the types and    */
  /* number of parameters are correct.  In all cases the FT_xxx types are  */
  /* cast to their TT_xxx counterparts inside the functions since FreeType */
  /* will always use the TT driver to create them.                         */


  /*************************************************************************/
  /*                                                                       */
  /* Face functions                                                        */
  /*                                                                       */
  FT_LOCAL( FT_Error )
  tt_face_init( FT_Stream      stream,
                FT_Face        ttface,      /* TT_Face */
                FT_Int         face_index,
                FT_Int         num_params,
                FT_Parameter*  params );

  FT_LOCAL( void )
  tt_face_done( FT_Face  ttface );          /* TT_Face */


  /*************************************************************************/
  /*                                                                       */
  /* Size functions                                                        */
  /*                                                                       */
  FT_LOCAL( FT_Error )
  tt_size_init( FT_Size  ttsize );          /* TT_Size */

  FT_LOCAL( void )
  tt_size_done( FT_Size  ttsize );          /* TT_Size */

#ifdef TT_USE_BYTECODE_INTERPRETER

  FT_LOCAL( FT_Error )
  tt_size_run_fpgm( TT_Size  size );

  FT_LOCAL( FT_Error )
  tt_size_run_prep( TT_Size  size );

#endif /* TT_USE_BYTECODE_INTERPRETER */

  FT_LOCAL( FT_Error )
  tt_size_reset( TT_Size  size );

  FT_LOCAL( FT_Error )
  tt_size_ready_bytecode( TT_Size  size );


  /*************************************************************************/
  /*                                                                       */
  /* Driver functions                                                      */
  /*                                                                       */
  FT_LOCAL( FT_Error )
  tt_driver_init( FT_Module  ttdriver );    /* TT_Driver */

  FT_LOCAL( void )
  tt_driver_done( FT_Module  ttdriver );    /* TT_Driver */


  /*************************************************************************/
  /*                                                                       */
  /* Slot functions                                                        */
  /*                                                                       */
  FT_LOCAL( FT_Error )
  tt_slot_init( FT_GlyphSlot  slot );


FT_END_HEADER

#endif /* __TTOBJS_H__ */


/* END */