ttcmap.c

奇趣公司比较新的qt/emd版本

        if ( sub == subs )
          goto Exit;
      }
      result = sub;
    }
  Exit:
    return result;
  }


  FT_CALLBACK_DEF( FT_UInt )
  tt_cmap2_char_index( TT_CMap    cmap,
                       FT_UInt32  char_code )
  {
    FT_Byte*  table   = cmap->data;
    FT_UInt   result  = 0;
    FT_Byte*  subheader;


    subheader = tt_cmap2_get_subheader( table, char_code );
    if ( subheader )
    {
      FT_Byte*  p   = subheader;
      FT_UInt   idx = (FT_UInt)(char_code & 0xFF);
      FT_UInt   start, count;
      FT_Int    delta;
      FT_UInt   offset;


      start  = TT_NEXT_USHORT( p );
      count  = TT_NEXT_USHORT( p );
      delta  = TT_NEXT_SHORT ( p );
      offset = TT_PEEK_USHORT( p );

      idx -= start;
      if ( idx < count && offset != 0 )
      {
        p  += offset + 2 * idx;
        idx = TT_PEEK_USHORT( p );

        if ( idx != 0 )
          result = (FT_UInt)( idx + delta ) & 0xFFFFU;
      }
    }
    return result;
  }


  FT_CALLBACK_DEF( FT_UInt )
  tt_cmap2_char_next( TT_CMap     cmap,
                      FT_UInt32  *pcharcode )
  {
    FT_Byte*   table    = cmap->data;
    FT_UInt    gindex   = 0;
    FT_UInt32  result   = 0;
    FT_UInt32  charcode = *pcharcode + 1;
    FT_Byte*   subheader;


    while ( charcode < 0x10000UL )
    {
      subheader = tt_cmap2_get_subheader( table, charcode );
      if ( subheader )
      {
        FT_Byte*  p       = subheader;
        FT_UInt   start   = TT_NEXT_USHORT( p );
        FT_UInt   count   = TT_NEXT_USHORT( p );
        FT_Int    delta   = TT_NEXT_SHORT ( p );
        FT_UInt   offset  = TT_PEEK_USHORT( p );
        FT_UInt   char_lo = (FT_UInt)( charcode & 0xFF );
        FT_UInt   pos, idx;


        if ( offset == 0 )
          goto Next_SubHeader;

        if ( char_lo < start )
        {
          char_lo = start;
          pos     = 0;
        }
        else
          pos = (FT_UInt)( char_lo - start );

        p       += offset + pos * 2;
        charcode = FT_PAD_FLOOR( charcode, 256 ) + char_lo;

        for ( ; pos < count; pos++, charcode++ )
        {
          idx = TT_NEXT_USHORT( p );

          if ( idx != 0 )
          {
            gindex = ( idx + delta ) & 0xFFFFU;
            if ( gindex != 0 )
            {
              result = charcode;
              goto Exit;
            }
          }
        }
      }

      /* jump to next sub-header, i.e. higher byte value */
    Next_SubHeader:
      charcode = FT_PAD_FLOOR( charcode, 256 ) + 256;
    }

  Exit:
    *pcharcode = result;

    return gindex;
  }


  FT_CALLBACK_DEF( FT_Error )
  tt_cmap2_get_info( TT_CMap       cmap,
                     TT_CMapInfo  *cmap_info )
  {
    FT_Byte*  p = cmap->data + 4;


    cmap_info->language = (FT_ULong)TT_PEEK_USHORT( p );

    return SFNT_Err_Ok;
  }


  FT_CALLBACK_TABLE_DEF
  const TT_CMap_ClassRec  tt_cmap2_class_rec =
  {
    {
      sizeof ( TT_CMapRec ),

      (FT_CMap_InitFunc)     tt_cmap_init,
      (FT_CMap_DoneFunc)     NULL,
      (FT_CMap_CharIndexFunc)tt_cmap2_char_index,
      (FT_CMap_CharNextFunc) tt_cmap2_char_next
    },
    2,
    (TT_CMap_ValidateFunc)   tt_cmap2_validate,
    (TT_CMap_Info_GetFunc)   tt_cmap2_get_info
  };

#endif /* TT_CONFIG_CMAP_FORMAT_2 */


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                           FORMAT 4                            *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  /*************************************************************************/
  /*                                                                       */
  /* TABLE OVERVIEW                                                        */
  /* --------------                                                        */
  /*                                                                       */
  /*   NAME          OFFSET         TYPE              DESCRIPTION          */
  /*                                                                       */
  /*   format        0              USHORT            must be 4            */
  /*   length        2              USHORT            table length         */
  /*                                                  in bytes             */
  /*   language      4              USHORT            Mac language code    */
  /*                                                                       */
  /*   segCountX2    6              USHORT            2*NUM_SEGS           */
  /*   searchRange   8              USHORT            2*(1 << LOG_SEGS)    */
  /*   entrySelector 10             USHORT            LOG_SEGS             */
  /*   rangeShift    12             USHORT            segCountX2 -         */
  /*                                                    searchRange        */
  /*                                                                       */
  /*   endCount      14             USHORT[NUM_SEGS]  end charcode for     */
  /*                                                  each segment; last   */
  /*                                                  is 0xFFFF            */
  /*                                                                       */
  /*   pad           14+NUM_SEGS*2  USHORT            padding              */
  /*                                                                       */
  /*   startCount    16+NUM_SEGS*2  USHORT[NUM_SEGS]  first charcode for   */
  /*                                                  each segment         */
  /*                                                                       */
  /*   idDelta       16+NUM_SEGS*4  SHORT[NUM_SEGS]   delta for each       */
  /*                                                  segment              */
  /*   idOffset      16+NUM_SEGS*6  SHORT[NUM_SEGS]   range offset for     */
  /*                                                  each segment; can be */
  /*                                                  zero                 */
  /*                                                                       */
  /*   glyphIds      16+NUM_SEGS*8  USHORT[]          array of glyph id    */
  /*                                                  ranges               */
  /*                                                                       */
  /* Character codes are modelled by a series of ordered (increasing)      */
  /* intervals called segments.  Each segment has start and end codes,     */
  /* provided by the `startCount' and `endCount' arrays.  Segments must    */
  /* not be overlapping and the last segment should always contain the     */
  /* `0xFFFF' endCount.                                                    */
  /*                                                                       */
  /* The fields `searchRange', `entrySelector' and `rangeShift' are better */
  /* ignored (they are traces of over-engineering in the TrueType          */
  /* specification).                                                       */
  /*                                                                       */
  /* Each segment also has a signed `delta', as well as an optional offset */
  /* within the `glyphIds' table.                                          */
  /*                                                                       */
  /* If a segment's idOffset is 0, the glyph index corresponding to any    */
  /* charcode within the segment is obtained by adding the value of        */
  /* `idDelta' directly to the charcode, modulo 65536.                     */
  /*                                                                       */
  /* Otherwise, a glyph index is taken from the glyph ids sub-array for    */
  /* the segment, and the value of `idDelta' is added to it.               */
  /*                                                                       */
  /*                                                                       */
  /* Finally, note that certain fonts contain invalid charmaps that        */
  /* contain end=0xFFFF, start=0xFFFF, delta=0x0001, offset=0xFFFF at the  */
  /* of their charmaps (e.g. opens___.ttf which comes with OpenOffice.org) */
  /* we need special code to deal with them correctly...                   */
  /*                                                                       */

#ifdef TT_CONFIG_CMAP_FORMAT_4

  typedef struct  TT_CMap4Rec_
  {
    TT_CMapRec  cmap;
    FT_UInt32   cur_charcode;   /* current charcode */
    FT_UInt     cur_gindex;     /* current glyph index */

    FT_UInt     num_ranges;
    FT_UInt     cur_range;
    FT_UInt     cur_start;
    FT_UInt     cur_end;
    FT_Int      cur_delta;
    FT_Byte*    cur_values;

  } TT_CMap4Rec, *TT_CMap4;


  FT_CALLBACK_DEF( FT_Error )
  tt_cmap4_init( TT_CMap4  cmap,
                 FT_Byte*  table )
  {
    FT_Byte*  p;


    cmap->cmap.data    = table;

    p                  = table + 6;
    cmap->num_ranges   = FT_PEEK_USHORT( p ) >> 1;
    cmap->cur_charcode = 0xFFFFFFFFUL;
    cmap->cur_gindex   = 0;

    return SFNT_Err_Ok;
  }


  static FT_Int
  tt_cmap4_set_range( TT_CMap4  cmap,
                      FT_UInt   range_index )
  {
    FT_Byte*  table = cmap->cmap.data;
    FT_Byte*  p;
    FT_UInt   num_ranges = cmap->num_ranges;


    while ( range_index < num_ranges )
    {
      FT_UInt  offset;


      p             = table + 14 + range_index * 2;
      cmap->cur_end = FT_PEEK_USHORT( p );

      p              += 2 + num_ranges * 2;
      cmap->cur_start = FT_PEEK_USHORT( p );

      p              += num_ranges * 2;
      cmap->cur_delta = FT_PEEK_SHORT( p );

      p     += num_ranges * 2;
      offset = FT_PEEK_USHORT( p );

      if ( offset != 0xFFFFU )
      {
        cmap->cur_values = offset ? p + offset : NULL;
        cmap->cur_range  = range_index;
        return 0;
      }

      /* we skip empty segments */
      range_index++;
    }

    return -1;
  }


  /* search the index of the charcode next to cmap->cur_charcode; */
  /* caller should call tt_cmap4_set_range with proper range      */
  /* before calling this function                                 */
  /*                                                              */
  static void
  tt_cmap4_next( TT_CMap4  cmap )
  {
    FT_UInt  charcode;


    if ( cmap->cur_charcode >= 0xFFFFUL )
      goto Fail;

    charcode = cmap->cur_charcode + 1;

    if ( charcode < cmap->cur_start )
      charcode = cmap->cur_start;

    for ( ;; )
    {
      FT_Byte*  values = cmap->cur_values;
      FT_UInt   end    = cmap->cur_end;
      FT_Int    delta  = cmap->cur_delta;


      if ( charcode <= end )
      {
        if ( values )
        {
          FT_Byte*  p = values + 2 * ( charcode - cmap->cur_start );


          do
          {
            FT_UInt  gindex = FT_NEXT_USHORT( p );


            if ( gindex != 0 )
            {
              gindex = (FT_UInt)( ( gindex + delta ) & 0xFFFFU );
              if ( gindex != 0 )
              {
                cmap->cur_charcode = charcode;
                cmap->cur_gindex   = gindex;
                return;
              }
            }
          } while ( ++charcode <= end );
        }
        else
        {
          do
          {
            FT_UInt  gindex = (FT_UInt)( ( charcode + delta ) & 0xFFFFU );


            if ( gindex != 0 )
            {
              cmap->cur_charcode = charcode;
              cmap->cur_gindex   = gindex;
              return;
            }
          } while ( ++charcode <= end );
        }
      }

      /* we need to find another range */
      if ( tt_cmap4_set_range( cmap, cmap->cur_range + 1 ) < 0 )
        break;

      if ( charcode < cmap->cur_start )
        charcode = cmap->cur_start;
    }

  Fail:
    cmap->cur_charcode = 0xFFFFFFFFUL;
    cmap->cur_gindex   = 0;
  }


  FT_CALLBACK_DEF( FT_Error )
  tt_cmap4_validate( FT_Byte*      table,
                     FT_Validator  valid )
  {
    FT_Byte*  p      = table + 2;               /* skip format */
    FT_UInt   length = TT_NEXT_USHORT( p );
    FT_Byte   *ends, *starts, *offsets, *deltas, *glyph_ids;
    FT_UInt   num_segs;
    FT_Error  error = SFNT_Err_Ok;


    if ( length < 16 )
      FT_INVALID_TOO_SHORT;

    /* in certain fonts, the `length' field is invalid and goes */
    /* out of bound.  We try to correct this here...            */
    if ( table + length > valid->limit )
    {
      if ( valid->level >= FT_VALIDATE_TIGHT )
        FT_INVALID_TOO_SHORT;

      length = (FT_UInt)( valid->limit - table );
    }

    p        = table + 6;
    num_segs = TT_NEXT_USHORT( p );   /* read segCountX2 */

    if ( valid->level >= FT_VALIDATE_PARANOID )
    {
      /* check that we have an even value here */
      if ( num_segs & 1 )
        FT_INVALID_DATA;