cffload.c

source code: Covert TXT to PDF

                    FT_ULong      offset )
  {
    FT_Memory  memory     = stream->memory;
    FT_Error   error      = 0;
    FT_UShort  glyph_sid;


    charset->offset = base_offset + offset;

    /* Get the format of the table. */
    if ( FILE_Seek( charset->offset ) ||
         READ_Byte( charset->format ) )
      goto Exit;

    /* If the the offset is greater than 2, we have to parse the */
    /* charset table.                                            */
    if ( offset > 2 )
    {
      FT_UInt  j;


      /* Allocate memory for sids. */
      if ( ALLOC( charset->sids, num_glyphs * sizeof ( FT_UShort ) ) )
        goto Exit;

      /* assign the .notdef glyph */
      charset->sids[0] = 0;

      switch ( charset->format )
      {
      case 0:
        for ( j = 1; j < num_glyphs; j++ )
        {
          if ( READ_UShort( glyph_sid ) )
            goto Exit;

          charset->sids[j] = glyph_sid;
        }
        break;

      case 1:
      case 2:
        {
          FT_UInt  nleft;
          FT_UInt  i;


          j = 1;

          while ( j < num_glyphs )
          {

            /* Read the first glyph sid of the range. */
            if ( READ_UShort( glyph_sid ) )
              goto Exit;

            /* Read the number of glyphs in the range.  */
            if ( charset->format == 2 )
            {
              if ( READ_UShort( nleft ) )
                goto Exit;
            }
            else
            {
              if ( READ_Byte( nleft ) )
                goto Exit;
            }

            /* Fill in the range of sids -- `nleft + 1' glyphs. */
            for ( i = 0; i <= nleft; i++, j++, glyph_sid++ )
              charset->sids[j] = glyph_sid;
          }
        }
        break;

      default:
        FT_ERROR(( "CFF_Load_Charset: invalid table format!\n" ));
        error = CFF_Err_Invalid_File_Format;
        goto Exit;
      }
    }
    else
    {
      /* Parse default tables corresponding to offset == 0, 1, or 2.  */
      /* CFF specification intimates the following:                   */
      /*                                                              */
      /* In order to use a predefined charset, the following must be  */
      /* true: The charset constructed for the glyphs in the font's   */
      /* charstrings dictionary must match the predefined charset in  */
      /* the first num_glyphs, and hence must match the predefined    */
      /* charset *exactly*.                                           */

      switch ( offset )
      {
      case 0:
        if ( num_glyphs != 229 )
        {
          FT_ERROR(("CFF_Load_Charset: implicit charset not equal to\n"
                    "predefined charset (Adobe ISO-Latin)!\n" ));
          error = CFF_Err_Invalid_File_Format;
          goto Exit;
        }

        /* Allocate memory for sids. */
        if ( ALLOC( charset->sids, num_glyphs * sizeof ( FT_UShort ) ) )
          goto Exit;

        /* Copy the predefined charset into the allocated memory. */
        MEM_Copy( charset->sids, cff_isoadobe_charset,
                  num_glyphs * sizeof ( FT_UShort ) );

        break;

      case 1:
        if ( num_glyphs != 166 )
        {
          FT_ERROR(( "CFF_Load_Charset: implicit charset not equal to\n"
                     "predefined charset (Adobe Expert)!\n" ));
          error = CFF_Err_Invalid_File_Format;
          goto Exit;
        }

        /* Allocate memory for sids. */
        if ( ALLOC( charset->sids, num_glyphs * sizeof ( FT_UShort ) ) )
          goto Exit;

        /* Copy the predefined charset into the allocated memory.     */
        MEM_Copy( charset->sids, cff_expert_charset,
                  num_glyphs * sizeof ( FT_UShort ) );

        break;

      case 2:
        if ( num_glyphs != 87 )
        {
          FT_ERROR(( "CFF_Load_Charset: implicit charset not equal to\n"
                     "predefined charset (Adobe Expert Subset)!\n" ));
          error = CFF_Err_Invalid_File_Format;
          goto Exit;
        }

        /* Allocate memory for sids. */
        if ( ALLOC( charset->sids, num_glyphs * sizeof ( FT_UShort ) ) )
          goto Exit;

        /* Copy the predefined charset into the allocated memory.     */
        MEM_Copy( charset->sids, cff_expertsubset_charset,
                  num_glyphs * sizeof ( FT_UShort ) );

        break;

      default:
        error = CFF_Err_Invalid_File_Format;
        goto Exit;
      }
    }

  Exit:

    /* Clean up if there was an error. */
    if ( error )
      if ( charset->sids )
      {
        if ( charset->sids )
          FREE( charset->sids );
        charset->format = 0;
        charset->offset = 0;
        charset->sids   = 0;
      }

    return error;
  }


  static FT_Error
  CFF_Load_Encoding( CFF_Encoding*  encoding,
                     CFF_Charset*   charset,
                     FT_UInt        num_glyphs,
                     FT_Stream      stream,
                     FT_ULong       base_offset,
                     FT_ULong       offset )
  {
    FT_Memory   memory = stream->memory;
    FT_Error    error  = 0;
    FT_UInt     count;
    FT_UInt     j;
    FT_UShort   glyph_sid;
    FT_Byte     glyph_code;


    /* Check for charset->sids.  If we do not have this, we fail. */
    if ( !charset->sids )
    {
      error = CFF_Err_Invalid_File_Format;
      goto Exit;
    }

    /* Allocate memory for sids/codes -- there are at most 256 sids/codes */
    /* for an encoding.                                                   */
    if ( ALLOC( encoding->sids,  256 * sizeof ( FT_UShort ) ) ||
         ALLOC( encoding->codes, 256 * sizeof ( FT_UShort ) ) )
      goto Exit;

    /* Zero out the code to gid/sid mappings. */
    for ( j = 0; j < 255; j++ )
    {
      encoding->sids [j] = 0;
      encoding->codes[j] = 0;
    }

    /* Note: The encoding table in a CFF font is indexed by glyph index,  */
    /* where the first encoded glyph index is 1.  Hence, we read the char */
    /* code (`glyph_code') at index j and make the assignment:            */
    /*                                                                    */
    /*    encoding->codes[glyph_code] = j + 1                             */
    /*                                                                    */
    /* We also make the assignment:                                       */
    /*                                                                    */
    /*    encoding->sids[glyph_code] = charset->sids[j + 1]               */
    /*                                                                    */
    /* This gives us both a code to GID and a code to SID mapping.        */

    if ( offset > 1 )
    {

      encoding->offset = base_offset + offset;

      /* we need to parse the table to determine its size */
      if ( FILE_Seek( encoding->offset ) ||
           READ_Byte( encoding->format ) ||
           READ_Byte( count )            )
        goto Exit;

      switch ( encoding->format & 0x7F )
      {
      case 0:
        for ( j = 1; j <= count; j++ )
        {
          if ( READ_Byte( glyph_code ) )
            goto Exit;

          /* Make sure j is not too big. */
          if ( j > num_glyphs )
            goto Exit;

          /* Assign code to GID mapping. */
          encoding->codes[glyph_code] = (FT_UShort)j;

          /* Assign code to SID mapping. */
          encoding->sids[glyph_code] = charset->sids[j];
        }

        break;

      case 1:
        {
          FT_Byte  nleft;
          FT_UInt  i = 1;
          FT_UInt  k;


          /* Parse the Format1 ranges. */
          for ( j = 0;  j < count; j++, i += nleft )
          {
            /* Read the first glyph code of the range. */
            if ( READ_Byte( glyph_code ) )
              goto Exit;

            /* Read the number of codes in the range. */
            if ( READ_Byte( nleft ) )
              goto Exit;

            /* Increment nleft, so we read `nleft + 1' codes/sids. */
            nleft++;

            /* Fill in the range of codes/sids. */
            for ( k = i; k < nleft + i; k++, glyph_code++ )
            {
              /* Make sure k is not too big. */
              if ( k > num_glyphs )
                goto Exit;

              /* Assign code to GID mapping. */
              encoding->codes[glyph_code] = (FT_UShort)k;

              /* Assign code to SID mapping. */
              encoding->sids[glyph_code] = charset->sids[k];
            }
          }
        }
        break;

      default:
        FT_ERROR(( "CFF_Load_Encoding: invalid table format!\n" ));
        error = CFF_Err_Invalid_File_Format;
        goto Exit;
      }

      /* Parse supplemental encodings, if any. */
      if ( encoding->format & 0x80 )
      {
        FT_UInt glyph_id;


        /* count supplements */
        if ( READ_Byte( count ) )
          goto Exit;

        for ( j = 0; j < count; j++ )
        {
          /* Read supplemental glyph code. */
          if ( READ_Byte( glyph_code ) )
            goto Exit;

          /* Read the SID associated with this glyph code. */
          if ( READ_UShort( glyph_sid ) )
            goto Exit;

          /* Assign code to SID mapping. */
          encoding->sids[glyph_code] = glyph_sid;

          /* First, lookup GID which has been assigned to */
          /* SID glyph_sid.                               */
          for ( glyph_id = 0; glyph_id < num_glyphs; glyph_id++ )
          {
            if ( charset->sids[glyph_id] == glyph_sid )
              break;
          }

          /* Now, make the assignment. */
          encoding->codes[glyph_code] = (FT_UShort)glyph_id;
        }
      }
    }
    else
    {
      FT_UInt i;


      /* We take into account the fact a CFF font can use a predefined  */
      /* encoding without containing all of the glyphs encoded by this  */
      /* encoding (see the note at the end of section 12 in the CFF     */
      /* specification).                                                */

      switch ( offset )
      {
      case 0:
        /* First, copy the code to SID mapping. */
        MEM_Copy( encoding->sids, cff_standard_encoding,
                  256 * sizeof ( FT_UShort ) );

        /* Construct code to GID mapping from code */
        /* to SID mapping and charset.             */
        for ( j = 0; j < 256; j++ )
        {
          /* If j is encoded, find the GID for it. */
          if ( encoding->sids[j] )
          {
            for ( i = 1; i < num_glyphs; i++ )
              /* We matched, so break. */
              if ( charset->sids[i] == encoding->sids[j] )
                break;

            /* i will be equal to num_glyphs if we exited the above */
            /* loop without a match.  In this case, we also have to */
            /* fix the code to SID mapping.                         */
            if ( i == num_glyphs )
            {
              encoding->codes[j] = 0;
              encoding->sids [j] = 0;
            }
            else
              encoding->codes[j] = (FT_UShort)i;
          }
        }
        break;

      case 1:
        /* First, copy the code to SID mapping. */
        MEM_Copy( encoding->sids, cff_expert_encoding,
                  256 * sizeof ( FT_UShort ) );

        /* Construct code to GID mapping from code to SID mapping */
        /* and charset.                                           */
        for ( j = 0; j < 256; j++ )
        {
          /* If j is encoded, find the GID for it. */
          if ( encoding->sids[j] )
          {
            for ( i = 1; i < num_glyphs; i++ )
              /* We matched, so break. */
              if ( charset->sids[i] == encoding->sids[j] )
                break;

            /* i will be equal to num_glyphs if we exited the above */
            /* loop without a match.  In this case, we also have to */
            /* fix the code to SID mapping.                         */
            if ( i == num_glyphs )
            {
              encoding->codes[j] = 0;
              encoding->sids [j] = 0;
            }
            else
              encoding->codes[j] = (FT_UShort)i;
          }
        }
        break;

      default:
        FT_ERROR(( "CFF_Load_Encoding: invalid table format!\n" ));
        error = CFF_Err_Invalid_File_Format;
        goto Exit;
      }
    }

  Exit:

    /* Clean up if there was an error. */
    if ( error )
    {
      if ( encoding->sids || encoding->codes )
      {
        if ( encoding->sids )
          FREE( encoding->sids );

        if ( encoding->codes )
          FREE( encoding->codes );

        charset->format = 0;
        charset->offset = 0;
        charset->sids   = 0;
      }
    }

    return error;
  }


  static FT_Error
  CFF_Load_SubFont( CFF_SubFont*  font,
                    CFF_Index*    index,
                    FT_UInt       font_index,
                    FT_Stream     stream,
                    FT_ULong      base_offset )
  {
    FT_Error        error;
    CFF_Parser      parser;
    FT_Byte*        dict;
    FT_ULong        dict_len;
    CFF_Font_Dict*  top  = &font->font_dict;
    CFF_Private*    priv = &font->private_dict;


    CFF_Parser_Init( &parser, CFF_CODE_TOPDICT, &font->font_dict );

    /* set defaults */
    MEM_Set( top, 0, sizeof ( *top ) );

    top->underline_position  = -100;
    top->underline_thickness = 50;
    top->charstring_type     = 2;
    top->font_matrix.xx      = 0x10000L;
    top->font_matrix.yy      = 0x10000L;
    top->cid_count           = 8720;

    error = CFF_Access_Element( index, font_index, &dict, &dict_len ) ||
            CFF_Parser_Run( &parser, dict, dict + dict_len );

    CFF_Forget_Element( index, &dict );

    if ( error )
      goto Exit;

    /* if it is a CID font, we stop there */
    if ( top->cid_registry )
      goto Exit;

    /* parse the private dictionary, if any */
    if ( top->private_offset && top->private_size )
    {
      /* set defaults */
      MEM_Set( priv, 0, sizeof ( *priv ) );

      priv->blue_shift       = 7;
      priv->blue_fuzz        = 1;
      priv->lenIV            = -1;
      priv->expansion_factor = (FT_Fixed)0.06 * 0x10000L;
      priv->blue_scale       = (FT_Fixed)0.039625 * 0x10000L;

      CFF_Parser_Init( &parser, CFF_CODE_PRIVATE, priv );

      if ( FILE_Seek( base_offset + font->font_dict.private_offset ) ||
           ACCESS_Frame( font->font_dict.private_size )              )
        goto Exit;

      error = CFF_Parser_Run( &parser,
                             (FT_Byte*)stream->cursor,
                             (FT_Byte*)stream->limit );
      FORGET_Frame();
      if ( error )
        goto Exit;
    }

    /* read the local subrs, if any */
    if ( priv->local_subrs_offset )
    {
      if ( FILE_Seek( base_offset + top->private_offset +
                      priv->local_subrs_offset ) )
        goto Exit;

      error = cff_new_index( &font->local_subrs_index, stream, 1 );
      if ( error )
        goto Exit;

      font->num_local_subrs = font->local_subrs_index.count;
      error = cff_explicit_index( &font->local_subrs_index,
                                     &font->local_subrs );
      if ( error )
        goto Exit;
    }

  Exit:
    return error;
  }


  static void
  CFF_Done_SubFont( FT_Memory     memory,
                    CFF_SubFont*  subfont )
  {
    if ( subfont )
    {
      cff_done_index( &subfont->local_subrs_index );
      FREE( subfont->local_subrs );
    }
  }


  FT_LOCAL_DEF FT_Error
  CFF_Load_Font( FT_Stream  stream,
                 FT_Int     face_index,
                 CFF_Font*  font )
  {
    static const FT_Frame_Field  cff_header_fields[] =
    {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  CFF_Font

      FT_FRAME_START( 4 ),
        FT_FRAME_BYTE( version_major ),
        FT_FRAME_BYTE( version_minor ),
        FT_FRAME_BYTE( header_size ),
        FT_FRAME_BYTE( absolute_offsize ),
      FT_FRAME_END
    };

    FT_Error        error;
    FT_Memory       memory = stream->memory;
    FT_ULong        base_offset;
    CFF_Font_Dict*  dict;


    MEM_Set( font, 0, sizeof ( *font ) );

    font->stream = stream;
    font->memory = memory;
    dict         = &font->top_font.font_dict;
    base_offset  = FILE_Pos();

    /* read CFF font header */
    if ( READ_Fields( cff_header_fields, font ) )
      goto Exit;

    /* check format */
    if ( font->version_major   != 1 ||
         font->header_size      < 4 ||
         font->absolute_offsize > 4 )
    {
      FT_TRACE2(( "[not a CFF font header!]\n" ));
      error = CFF_Err_Unknown_File_Format;
      goto Exit;
    }

    /* skip the rest of the header */
    if ( FILE_Skip( font->header_size - 4 ) )
      goto Exit;

    /* read the name, top dict, string and global subrs index */
    if ( FT_SET_ERROR( cff_new_index( &font->name_index,         stream, 0 )) ||
         FT_SET_ERROR( cff_new_index( &font->font_dict_index,    stream, 0 )) ||
         FT_SET_ERROR( cff_new_index( &font->string_index,       stream, 0 )) ||
         FT_SET_ERROR( cff_new_index( &font->global_subrs_index, stream, 1 )) )
      goto Exit;

    /* well, we don't really forget the `disabled' fonts... */
    font->num_faces = font->name_index.count;
    if ( face_index >= (FT_Int)font->num_faces )
    {
      FT_ERROR(( "CFF_Load_Font: incorrect face index = %d\n",
                 face_index ));
      error = CFF_Err_Invalid_Argument;
    }

    /* in case of a font format check, simply exit now */
    if ( face_index < 0 )
      goto Exit;

    /* now, parse the top-level font dictionary */
    error = CFF_Load_SubFont( &font->top_font,
                              &font->font_dict_index,
                              face_index,
                              stream,
                              base_offset );
    if ( error )
      goto Exit;

    /* now, check for a CID font */
    if ( dict->cid_registry )
    {
      CFF_Index     fd_index;
      CFF_SubFont*  sub;
      FT_UInt       index;


      /* this is a CID-keyed font, we must now allocate a table of */
      /* sub-fonts, then load each of them separately              */
      if ( FILE_Seek( base_offset + dict->cid_fd_array_offset ) )
        goto Exit;

      error = cff_new_index( &fd_index, stream, 0 );
      if ( error )
        goto Exit;

      if ( fd_index.count > CFF_MAX_CID_FONTS )
      {
        FT_ERROR(( "CFF_Load_Font: FD array too large in CID font\n" ));
        goto Fail_CID;
      }

      /* allocate & read each font dict independently */
      font->num_subfonts = fd_index.count;
      if ( ALLOC_ARRAY( sub, fd_index.count, CFF_SubFont ) )
        goto Fail_CID;

      /* setup pointer table */
      for ( index = 0; index < fd_index.count; index++ )
        font->subfonts[index] = sub + index;

      /* now load each sub font independently */
      for ( index = 0; index < fd_index.count; index++ )
      {
        sub = font->subfonts[index];
        error = CFF_Load_SubFont( sub, &fd_index, index,
                                  stream, base_offset );
        if ( error )
          goto Fail_CID;
      }

      /* now load the FD Select array */
      error = CFF_Load_FD_Select( &font->fd_select,
                                  dict->cid_count,
                                  stream,
                                  base_offset + dict->cid_fd_select_offset );

    Fail_CID:
      cff_done_index( &fd_index );

      if ( error )
        goto Exit;
    }
    else
      font->num_subfonts = 0;

    /* read the charstrings index now */
    if ( dict->charstrings_offset == 0 )
    {
      FT_ERROR(( "CFF_Load_Font: no charstrings offset!\n" ));
      error = CFF_Err_Unknown_File_Format;
      goto Exit;
    }

    if ( FILE_Seek( base_offset + dict->charstrings_offset ) )
      goto Exit;

    error = cff_new_index( &font->charstrings_index, stream, 0 );
    if ( error )
      goto Exit;

    /* explicit the global subrs */
    font->num_global_subrs = font->global_subrs_index.count;
    font->num_glyphs       = font->charstrings_index.count;

    error = cff_explicit_index( &font->global_subrs_index,
                                &font->global_subrs ) ;

    if ( error )
      goto Exit;

    /* read the Charset and Encoding tables when available */
    error = CFF_Load_Charset( &font->charset, font->num_glyphs, stream,
                              base_offset, dict->charset_offset );
    if ( error )
      goto Exit;

    error = CFF_Load_Encoding( &font->encoding,
                               &font->charset,
                               font->num_glyphs,
                               stream,
                               base_offset,
                               dict->encoding_offset );
    if ( error )
      goto Exit;

    /* get the font name */
    font->font_name = CFF_Get_Name( &font->name_index, face_index );

  Exit:
    return error;
  }


  FT_LOCAL_DEF void
  CFF_Done_Font( CFF_Font*  font )
  {
    FT_Memory  memory = font->memory;
    FT_UInt    index;


    cff_done_index( &font->global_subrs_index );
    cff_done_index( &font->string_index );
    cff_done_index( &font->font_dict_index );
    cff_done_index( &font->name_index );
    cff_done_index( &font->charstrings_index );

    /* release font dictionaries, but only if working with */
    /* a CID keyed CFF font                                */
    if ( font->num_subfonts > 0 )
    {
      for ( index = 0; index < font->num_subfonts; index++ )
        CFF_Done_SubFont( memory, font->subfonts[index] );

      FREE( font->subfonts );
    }

    CFF_Done_Encoding( &font->encoding, font->stream );
    CFF_Done_Charset( &font->charset, font->stream );

    CFF_Done_SubFont( memory, &font->top_font );

    CFF_Done_FD_Select( &font->fd_select, font->stream );

    FREE( font->global_subrs );
    FREE( font->font_name );
  }


/* END */