ttcmap0.c

下载来的一个看图软件的源代码

    /* check glyph indices */
    if ( valid->level >= FT_VALIDATE_TIGHT )
    {
      FT_UInt  gindex;


      for ( ; count > 0; count-- )
      {
        gindex = TT_NEXT_USHORT( p );
        if ( gindex >= TT_VALID_GLYPH_COUNT( valid ) )
          FT_INVALID_GLYPH_ID;
      }
    }
  }


  FT_CALLBACK_DEF( FT_UInt )
  tt_cmap10_char_index( TT_CMap    cmap,
                        FT_UInt32  char_code )
  {
    FT_Byte*   table  = cmap->data;
    FT_UInt    result = 0;
    FT_Byte*   p      = table + 12;
    FT_UInt32  start  = TT_NEXT_ULONG( p );
    FT_UInt32  count  = TT_NEXT_ULONG( p );
    FT_UInt32  idx    = (FT_ULong)( char_code - start );


    if ( idx < count )
    {
      p     += 2 * idx;
      result = TT_PEEK_USHORT( p );
    }
    return result;
  }


  FT_CALLBACK_DEF( FT_UInt )
  tt_cmap10_char_next( TT_CMap     cmap,
                       FT_UInt32  *pchar_code )
  {
    FT_Byte*   table     = cmap->data;
    FT_UInt32  char_code = *pchar_code + 1;
    FT_UInt    gindex    = 0;
    FT_Byte*   p         = table + 12;
    FT_UInt32  start     = TT_NEXT_ULONG( p );
    FT_UInt32  count     = TT_NEXT_ULONG( p );
    FT_UInt32  idx;


    if ( char_code < start )
      char_code = start;

    idx = (FT_UInt32)( char_code - start );
    p  += 2 * idx;

    for ( ; idx < count; idx++ )
    {
      gindex = TT_NEXT_USHORT( p );
      if ( gindex != 0 )
        break;
      char_code++;
    }

    *pchar_code = char_code;
    return gindex;
  }


  FT_CALLBACK_TABLE_DEF
  const TT_CMap_ClassRec  tt_cmap10_class_rec =
  {
    {
      sizeof ( TT_CMapRec ),

      (FT_CMap_InitFunc)     tt_cmap_init,
      (FT_CMap_DoneFunc)     NULL,
      (FT_CMap_CharIndexFunc)tt_cmap10_char_index,
      (FT_CMap_CharNextFunc) tt_cmap10_char_next
    },
    10,
    (TT_CMap_ValidateFunc)   tt_cmap10_validate
  };

#endif /* TT_CONFIG_CMAP_FORMAT_10 */


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                          FORMAT 12                            *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  /*************************************************************************/
  /*                                                                       */
  /* TABLE OVERVIEW                                                        */
  /* --------------                                                        */
  /*                                                                       */
  /*   NAME        OFFSET     TYPE       DESCRIPTION                       */
  /*                                                                       */
  /*   format      0          USHORT     must be 12                        */
  /*   reserved    2          USHORT     reserved                          */
  /*   length      4          ULONG      length in bytes                   */
  /*   language    8          ULONG      Mac language code                 */
  /*   count       12         ULONG      number of groups                  */
  /*               16                                                      */
  /*                                                                       */
  /* This header is followed by `count' groups of the following format:    */
  /*                                                                       */
  /*   start       0          ULONG      first charcode                    */
  /*   end         4          ULONG      last charcode                     */
  /*   startId     8          ULONG      start glyph id for the group      */
  /*                                                                       */

#ifdef TT_CONFIG_CMAP_FORMAT_12

  FT_CALLBACK_DEF( void )
  tt_cmap12_validate( FT_Byte*      table,
                      FT_Validator  valid )
  {
    FT_Byte*   p;
    FT_ULong   length;
    FT_ULong   num_groups;


    if ( table + 16 > valid->limit )
      FT_INVALID_TOO_SHORT;

    p      = table + 4;
    length = TT_NEXT_ULONG( p );

    p          = table + 12;
    num_groups = TT_NEXT_ULONG( p );

    if ( table + length > valid->limit || length < 16 + 12 * num_groups )
      FT_INVALID_TOO_SHORT;

    /* check groups, they must be in increasing order */
    {
      FT_ULong  n, start, end, start_id, last = 0;


      for ( n = 0; n < num_groups; n++ )
      {
        start    = TT_NEXT_ULONG( p );
        end      = TT_NEXT_ULONG( p );
        start_id = TT_NEXT_ULONG( p );

        if ( start > end )
          FT_INVALID_DATA;

        if ( n > 0 && start <= last )
          FT_INVALID_DATA;

        if ( valid->level >= FT_VALIDATE_TIGHT )
        {
          if ( start_id + end - start >= TT_VALID_GLYPH_COUNT( valid ) )
            FT_INVALID_GLYPH_ID;
        }

        last = end;
      }
    }
  }


  FT_CALLBACK_DEF( FT_UInt )
  tt_cmap12_char_index( TT_CMap    cmap,
                        FT_UInt32  char_code )
  {
    FT_UInt    result     = 0;
    FT_Byte*   table      = cmap->data;
    FT_Byte*   p          = table + 12;
    FT_UInt32  num_groups = TT_NEXT_ULONG( p );
    FT_UInt32  start, end, start_id;


    for ( ; num_groups > 0; num_groups-- )
    {
      start    = TT_NEXT_ULONG( p );
      end      = TT_NEXT_ULONG( p );
      start_id = TT_NEXT_ULONG( p );

      if ( char_code < start )
        break;

      if ( char_code <= end )
      {
        result = (FT_UInt)( start_id + char_code - start );
        break;
      }
    }
    return result;
  }


  FT_CALLBACK_DEF( FT_UInt )
  tt_cmap12_char_next( TT_CMap     cmap,
                       FT_UInt32  *pchar_code )
  {
    FT_Byte*   table      = cmap->data;
    FT_UInt32  result     = 0;
    FT_UInt32  char_code  = *pchar_code + 1;
    FT_UInt    gindex     = 0;
    FT_Byte*   p          = table + 12;
    FT_UInt32  num_groups = TT_NEXT_ULONG( p );
    FT_UInt32  start, end, start_id;


    p = table + 16;

    for ( ; num_groups > 0; num_groups-- )
    {
      start    = TT_NEXT_ULONG( p );
      end      = TT_NEXT_ULONG( p );
      start_id = TT_NEXT_ULONG( p );

      if ( char_code < start )
        char_code = start;

      if ( char_code <= end )
      {
        gindex = (FT_UInt)(char_code - start + start_id);
        if ( gindex != 0 )
        {
          result = char_code;
          goto Exit;
        }
      }
    }

  Exit:
    *pchar_code = result;
    return gindex;
  }


  FT_CALLBACK_TABLE_DEF
  const TT_CMap_ClassRec  tt_cmap12_class_rec =
  {
    {
      sizeof ( TT_CMapRec ),

      (FT_CMap_InitFunc)     tt_cmap_init,
      (FT_CMap_DoneFunc)     NULL,
      (FT_CMap_CharIndexFunc)tt_cmap12_char_index,
      (FT_CMap_CharNextFunc) tt_cmap12_char_next
    },
    12,
    (TT_CMap_ValidateFunc)   tt_cmap12_validate
  };


#endif /* TT_CONFIG_CMAP_FORMAT_12 */


  static const TT_CMap_Class  tt_cmap_classes[] =
  {
#ifdef TT_CONFIG_CMAP_FORMAT_0
    &tt_cmap0_class_rec,
#endif

#ifdef TT_CONFIG_CMAP_FORMAT_2
    &tt_cmap2_class_rec,
#endif

#ifdef TT_CONFIG_CMAP_FORMAT_4
    &tt_cmap4_class_rec,
#endif

#ifdef TT_CONFIG_CMAP_FORMAT_6
    &tt_cmap6_class_rec,
#endif

#ifdef TT_CONFIG_CMAP_FORMAT_8
    &tt_cmap8_class_rec,
#endif

#ifdef TT_CONFIG_CMAP_FORMAT_10
    &tt_cmap10_class_rec,
#endif

#ifdef TT_CONFIG_CMAP_FORMAT_12
    &tt_cmap12_class_rec,
#endif

    NULL,
  };


  /* parse the `cmap' table and build the corresponding TT_CMap objects */
  /* in the current face                                                */
  /*                                                                    */
  FT_LOCAL_DEF( FT_Error )
  tt_face_build_cmaps( TT_Face  face )
  {
    FT_Byte*           table = face->cmap_table;
    FT_Byte*           limit = table + face->cmap_size;
    FT_UInt volatile   num_cmaps;
    FT_Byte* volatile  p     = table;


    if ( p + 4 > limit )
      return SFNT_Err_Invalid_Table;

    /* only recognize format 0 */
    if ( TT_NEXT_USHORT( p ) != 0 )
    {
      p -= 2;
      FT_ERROR(( "tt_face_build_cmaps: unsupported `cmap' table format = %d\n",
                 TT_PEEK_USHORT( p ) ));
      return SFNT_Err_Invalid_Table;
    }

    num_cmaps = TT_NEXT_USHORT( p );

    for ( ; num_cmaps > 0 && p + 8 <= limit; num_cmaps-- )
    {
      FT_CharMapRec  charmap;
      FT_UInt32      offset;


      charmap.platform_id = TT_NEXT_USHORT( p );
      charmap.encoding_id = TT_NEXT_USHORT( p );
      charmap.face        = FT_FACE( face );
      charmap.encoding    = FT_ENCODING_NONE;  /* will be filled later */
      offset              = TT_NEXT_ULONG( p );

      if ( offset && table + offset + 2 < limit )
      {
        FT_Byte*                       cmap   = table + offset;
        volatile FT_UInt               format = TT_PEEK_USHORT( cmap );
        const TT_CMap_Class* volatile  pclazz = tt_cmap_classes;
        TT_CMap_Class                  clazz;


        for ( ; *pclazz; pclazz++ )
        {
          clazz = *pclazz;
          if ( clazz->format == format )
          {
            volatile TT_ValidatorRec  valid;


            ft_validator_init( FT_VALIDATOR( &valid ), cmap, limit,
                               FT_VALIDATE_DEFAULT );

            valid.num_glyphs = (FT_UInt)face->root.num_glyphs;

            if ( ft_setjmp( FT_VALIDATOR( &valid )->jump_buffer ) == 0 )
            {
              /* validate this cmap sub-table */
              clazz->validate( cmap, FT_VALIDATOR( &valid ) );
            }

            if ( valid.validator.error == 0 )
              (void)FT_CMap_New( (FT_CMap_Class)clazz, cmap, &charmap, NULL );
            else
            {
              FT_ERROR(( "tt_face_build_cmaps:" ));
              FT_ERROR(( " broken cmap sub-table ignored!\n" ));
            }
          }
        }
      }
    }

    return 0;
  }


/* END */