ttcmap.c

奇趣公司比较新的qt/emd版本

    }

    num_segs /= 2;

    if ( length < 16 + num_segs * 2 * 4 )
      FT_INVALID_TOO_SHORT;

    /* check the search parameters - even though we never use them */
    /*                                                             */
    if ( valid->level >= FT_VALIDATE_PARANOID )
    {
      /* check the values of 'searchRange', 'entrySelector', 'rangeShift' */
      FT_UInt  search_range   = TT_NEXT_USHORT( p );
      FT_UInt  entry_selector = TT_NEXT_USHORT( p );
      FT_UInt  range_shift    = TT_NEXT_USHORT( p );


      if ( ( search_range | range_shift ) & 1 )  /* must be even values */
        FT_INVALID_DATA;

      search_range /= 2;
      range_shift  /= 2;

      /* `search range' is the greatest power of 2 that is <= num_segs */

      if ( search_range                > num_segs                 ||
           search_range * 2            < num_segs                 ||
           search_range + range_shift != num_segs                 ||
           search_range               != ( 1U << entry_selector ) )
        FT_INVALID_DATA;
    }

    ends      = table   + 14;
    starts    = table   + 16 + num_segs * 2;
    deltas    = starts  + num_segs * 2;
    offsets   = deltas  + num_segs * 2;
    glyph_ids = offsets + num_segs * 2;

    /* check last segment, its end count must be FFFF */
    if ( valid->level >= FT_VALIDATE_PARANOID )
    {
      p = ends + ( num_segs - 1 ) * 2;
      if ( TT_PEEK_USHORT( p ) != 0xFFFFU )
        FT_INVALID_DATA;
    }

    {
      FT_UInt  start, end, offset, n;
      FT_UInt  last_start = 0, last_end = 0;
      FT_Int   delta;
      FT_Byte*  p_start   = starts;
      FT_Byte*  p_end     = ends;
      FT_Byte*  p_delta   = deltas;
      FT_Byte*  p_offset  = offsets;


      for ( n = 0; n < num_segs; n++ )
      {
        p      = p_offset;
        start  = TT_NEXT_USHORT( p_start );
        end    = TT_NEXT_USHORT( p_end );
        delta  = TT_NEXT_SHORT( p_delta );
        offset = TT_NEXT_USHORT( p_offset );

        if ( start > end )
          FT_INVALID_DATA;

        /* this test should be performed at default validation level;  */
        /* unfortunately, some popular Asian fonts present overlapping */
        /* ranges in their charmaps                                    */
        /*                                                             */
        if ( start <= last_end && n > 0 )
        {
          if ( valid->level >= FT_VALIDATE_TIGHT )
            FT_INVALID_DATA;
          else
          {
            /* allow overlapping segments, provided their start points */
            /* and end points, respectively, are in ascending order.   */
            /*                                                         */
            if ( last_start > start || last_end > end )
              error |= TT_CMAP_FLAG_UNSORTED;
            else
              error |= TT_CMAP_FLAG_OVERLAPPING;
          }
        }

        if ( offset && offset != 0xFFFFU )
        {
          p += offset;  /* start of glyph id array */

          /* check that we point within the glyph ids table only */
          if ( valid->level >= FT_VALIDATE_TIGHT )
          {
            if ( p < glyph_ids                                ||
                 p + ( end - start + 1 ) * 2 > table + length )
              FT_INVALID_DATA;
          }
          else
          {
            if ( p < glyph_ids                              ||
                 p + ( end - start + 1 ) * 2 > valid->limit )
              FT_INVALID_DATA;
          }

          /* check glyph indices within the segment range */
          if ( valid->level >= FT_VALIDATE_TIGHT )
          {
            FT_UInt  i, idx;


            for ( i = start; i < end; i++ )
            {
              idx = FT_NEXT_USHORT( p );
              if ( idx != 0 )
              {
                idx = (FT_UInt)( idx + delta ) & 0xFFFFU;

                if ( idx >= TT_VALID_GLYPH_COUNT( valid ) )
                  FT_INVALID_GLYPH_ID;
              }
            }
          }
        }
        else if ( offset == 0xFFFFU )
        {
          /* Some fonts (erroneously?) use a range offset of 0xFFFF */
          /* to mean missing glyph in cmap table                    */
          /*                                                        */
          if ( valid->level >= FT_VALIDATE_PARANOID                     ||
               n != num_segs - 1                                        ||
               !( start == 0xFFFFU && end == 0xFFFFU && delta == 0x1U ) )
            FT_INVALID_DATA;
        }

        last_start = start;
        last_end   = end;
      }
    }

    return error;
  }


  static FT_UInt
  tt_cmap4_char_map_linear( TT_CMap   cmap,
                            FT_UInt*  pcharcode,
                            FT_Bool   next )
  {
    FT_UInt    num_segs2, start, end, offset;
    FT_Int     delta;
    FT_UInt    i, num_segs;
    FT_UInt32  charcode = *pcharcode;
    FT_UInt    gindex   = 0;
    FT_Byte*   p;


    p = cmap->data + 6;
    num_segs2 = FT_PAD_FLOOR( TT_PEEK_USHORT( p ), 2 );

    num_segs = num_segs2 >> 1;

    if ( !num_segs )
      return 0;

    if ( next )
      charcode++;

    /* linear search */
    for ( ; charcode <= 0xFFFFU; charcode++ )
    {
      FT_Byte*  q;


      p = cmap->data + 14;               /* ends table   */
      q = cmap->data + 16 + num_segs2;   /* starts table */

      for ( i = 0; i < num_segs; i++ )
      {
        end   = TT_NEXT_USHORT( p );
        start = TT_NEXT_USHORT( q );

        if ( charcode >= start && charcode <= end )
        {
          p       = q - 2 + num_segs2;
          delta   = TT_PEEK_SHORT( p );
          p      += num_segs2;
          offset  = TT_PEEK_USHORT( p );

          if ( offset == 0xFFFFU )
            continue;

          if ( offset )
          {
            p += offset + ( charcode - start ) * 2;
            gindex = TT_PEEK_USHORT( p );
            if ( gindex != 0 )
              gindex = (FT_UInt)( gindex + delta ) & 0xFFFFU;
          }
          else
            gindex = (FT_UInt)( charcode + delta ) & 0xFFFFU;

          break;
        }
      }

      if ( !next || gindex )
        break;
    }

    if ( next && gindex )
      *pcharcode = charcode;

    return gindex;
  }


  static FT_UInt
  tt_cmap4_char_map_binary( TT_CMap   cmap,
                            FT_UInt*  pcharcode,
                            FT_Bool   next )
  {
    FT_UInt   num_segs2, start, end, offset;
    FT_Int    delta;
    FT_UInt   max, min, mid, num_segs;
    FT_UInt   charcode = *pcharcode;
    FT_UInt   gindex   = 0;
    FT_Byte*  p;


    p = cmap->data + 6;
    num_segs2 = FT_PAD_FLOOR( TT_PEEK_USHORT( p ), 2 );

    if ( !num_segs2 )
      return 0;

    num_segs = num_segs2 >> 1;

    /* make compiler happy */
    mid = num_segs;
    end = 0xFFFFU;

    if ( next )
      charcode++;

    min = 0;
    max = num_segs;

    /* binary search */
    while ( min < max )
    {
      mid    = ( min + max ) >> 1;
      p      = cmap->data + 14 + mid * 2;
      end    = TT_PEEK_USHORT( p );
      p     += 2 + num_segs2;
      start  = TT_PEEK_USHORT( p );

      if ( charcode < start )
        max = mid;
      else if ( charcode > end )
        min = mid + 1;
      else
      {
        p     += num_segs2;
        delta  = TT_PEEK_SHORT( p );
        p     += num_segs2;
        offset = TT_PEEK_USHORT( p );

        /* search the first segment containing `charcode' */
        if ( cmap->flags & TT_CMAP_FLAG_OVERLAPPING )
        {
          FT_UInt  i;


          /* call the current segment `max' */
          max = mid;

          if ( offset == 0xFFFFU )
            mid = max + 1;

          /* search in segments before the current segment */
          for ( i = max ; i > 0; i-- )
          {
            FT_UInt   prev_end;
            FT_Byte*  old_p;


            old_p    = p;
            p        = cmap->data + 14 + ( i - 1 ) * 2;
            prev_end = TT_PEEK_USHORT( p );

            if ( charcode > prev_end )
            {
              p = old_p;
              break;
            }

            end    = prev_end;
            p     += 2 + num_segs2;
            start  = TT_PEEK_USHORT( p );
            p     += num_segs2;
            delta  = TT_PEEK_SHORT( p );
            p     += num_segs2;
            offset = TT_PEEK_USHORT( p );

            if ( offset != 0xFFFFU )
              mid = i - 1;
          }

          /* no luck */
          if ( mid == max + 1 )
          {
            if ( i != max )
            {
              p      = cmap->data + 14 + max * 2;
              end    = TT_PEEK_USHORT( p );
              p     += 2 + num_segs2;
              start  = TT_PEEK_USHORT( p );
              p     += num_segs2;
              delta  = TT_PEEK_SHORT( p );
              p     += num_segs2;
              offset = TT_PEEK_USHORT( p );
            }

            mid = max;

            /* search in segments after the current segment */
            for ( i = max + 1; i < num_segs; i++ )
            {
              FT_UInt  next_end, next_start;


              p          = cmap->data + 14 + i * 2;
              next_end   = TT_PEEK_USHORT( p );
              p         += 2 + num_segs2;
              next_start = TT_PEEK_USHORT( p );

              if ( charcode < next_start )
                break;

              end    = next_end;
              start  = next_start;
              p     += num_segs2;
              delta  = TT_PEEK_SHORT( p );
              p     += num_segs2;
              offset = TT_PEEK_USHORT( p );

              if ( offset != 0xFFFFU )
                mid = i;
            }
            i--;

            /* still no luck */
            if ( mid == max )
            {
              mid = i;

              break;
            }
          }

          /* end, start, delta, and offset are for the i'th segment */
          if ( mid != i )
          {
            p      = cmap->data + 14 + mid * 2;
            end    = TT_PEEK_USHORT( p );
            p     += 2 + num_segs2;
            start  = TT_PEEK_USHORT( p );
            p     += num_segs2;
            delta  = TT_PEEK_SHORT( p );
            p     += num_segs2;
            offset = TT_PEEK_USHORT( p );
          }
        }
        else
        {
          if ( offset == 0xFFFFU )
            break;
        }

        if ( offset )
        {
          p += offset + ( charcode - start ) * 2;
          gindex = TT_PEEK_USHORT( p );
          if ( gindex != 0 )
            gindex = (FT_UInt)( gindex + delta ) & 0xFFFFU;
        }
        else
          gindex = (FT_UInt)( charcode + delta ) & 0xFFFFU;

        break;
      }
    }

    if ( next )
    {
      TT_CMap4  cmap4 = (TT_CMap4)cmap;


      /* if `charcode' is not in any segment, then `mid' is */
      /* the segment nearest to `charcode'                  */
      /*                                                    */

      if ( charcode > end )
      {
        mid++;
        if ( mid == num_segs )