cffgload.c

source code: Covert TXT to PDF

    if ( !builder->load_points )
    {
      outline->n_contours++;
      return CFF_Err_Ok;
    }

    error = FT_GlyphLoader_Check_Points( builder->loader, 0, 1 );
    if ( !error )
    {
      if ( outline->n_contours > 0 )
        outline->contours[outline->n_contours - 1] =
          (short)( outline->n_points - 1 );

      outline->n_contours++;
    }

    return error;
  }


  /* if a path was begun, add its first on-curve point */
  static FT_Error
  start_point( CFF_Builder*  builder,
               FT_Pos        x,
               FT_Pos        y )
  {
    FT_Error  error = 0;


    /* test whether we are building a new contour */
    if ( !builder->path_begun )
    {
      builder->path_begun = 1;
      error = add_contour( builder );
      if ( !error )
        error = add_point1( builder, x, y );
    }
    return error;
  }


  /* close the current contour */
  static void
  close_contour( CFF_Builder*  builder )
  {
    FT_Outline*  outline = builder->current;

    /* XXXX: We must not include the last point in the path if it */
    /*       is located on the first point.                       */
    if ( outline->n_points > 1 )
    {
      FT_Int      first   = 0;
      FT_Vector*  p1      = outline->points + first;
      FT_Vector*  p2      = outline->points + outline->n_points - 1;
      FT_Byte*    control = (FT_Byte*)outline->tags + outline->n_points - 1;


      if ( outline->n_contours > 1 )
      {
        first = outline->contours[outline->n_contours - 2] + 1;
        p1    = outline->points + first;
      }

      /* `delete' last point only if it coincides with the first */
      /* point and it is not a control point (which can happen). */
      if ( p1->x == p2->x && p1->y == p2->y )
        if ( *control == FT_Curve_Tag_On )
          outline->n_points--;
    }

    if ( outline->n_contours > 0 )
      outline->contours[outline->n_contours - 1] =
        (short)( outline->n_points - 1 );
  }


  static FT_Int
  cff_lookup_glyph_by_stdcharcode( CFF_Font*  cff,
                                   FT_Int     charcode )
  {
    FT_UInt    n;
    FT_UShort  glyph_sid;


    /* check range of standard char code */
    if ( charcode < 0 || charcode > 255 )
      return -1;

    /* Get code to SID mapping from `cff_standard_encoding'. */
    glyph_sid = CFF_Get_Standard_Encoding( (FT_UInt)charcode );

    for ( n = 0; n < cff->num_glyphs; n++ )
    {
      if ( cff->charset.sids[n] == glyph_sid )
        return n;
    }

    return -1;
  }


  static FT_Error
  cff_operator_seac( CFF_Decoder*  decoder,
                     FT_Pos        adx,
                     FT_Pos        ady,
                     FT_Int        bchar,
                     FT_Int        achar )
  {
    FT_Error     error;
    FT_Int       bchar_index, achar_index, n_base_points;
    FT_Outline*  base = decoder->builder.base;
    TT_Face      face = decoder->builder.face;
    CFF_Font*    cff  = (CFF_Font*)(face->extra.data);
    FT_Vector    left_bearing, advance;
    FT_Byte*     charstring;
    FT_ULong     charstring_len;


    bchar_index = cff_lookup_glyph_by_stdcharcode( cff, bchar );
    achar_index = cff_lookup_glyph_by_stdcharcode( cff, achar );

    if ( bchar_index < 0 || achar_index < 0 )
    {
      FT_ERROR(( "cff_operator_seac:" ));
      FT_ERROR(( " invalid seac character code arguments\n" ));
      return CFF_Err_Syntax_Error;
    }

    /* If we are trying to load a composite glyph, do not load the */
    /* accent character and return the array of subglyphs.         */
    if ( decoder->builder.no_recurse )
    {
      FT_GlyphSlot     glyph  = (FT_GlyphSlot)decoder->builder.glyph;
      FT_GlyphLoader*  loader = glyph->internal->loader;
      FT_SubGlyph*     subg;


      /* reallocate subglyph array if necessary */
      error = FT_GlyphLoader_Check_Subglyphs( loader, 2 );
      if ( error )
        goto Exit;

      subg = loader->current.subglyphs;

      /* subglyph 0 = base character */
      subg->index = bchar_index;
      subg->flags = FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES |
                    FT_SUBGLYPH_FLAG_USE_MY_METRICS;
      subg->arg1  = 0;
      subg->arg2  = 0;
      subg++;

      /* subglyph 1 = accent character */
      subg->index = achar_index;
      subg->flags = FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES;
      subg->arg1  = adx;
      subg->arg2  = ady;

      /* set up remaining glyph fields */
      glyph->num_subglyphs = 2;
      glyph->subglyphs     = loader->base.subglyphs;
      glyph->format        = ft_glyph_format_composite;

      loader->current.num_subglyphs = 2;
    }

    /* First load `bchar' in builder */
    error = CFF_Access_Element( &cff->charstrings_index, bchar_index,
                                &charstring, &charstring_len );
    if ( !error )
    {
      error = CFF_Parse_CharStrings( decoder, charstring, charstring_len );

      if ( error )
        goto Exit;

      CFF_Forget_Element( &cff->charstrings_index, &charstring );
    }

    n_base_points = base->n_points;

    /* Save the left bearing and width of the base character */
    /* as they will be erased by the next load.              */

    left_bearing = decoder->builder.left_bearing;
    advance      = decoder->builder.advance;

    decoder->builder.left_bearing.x = 0;
    decoder->builder.left_bearing.y = 0;

    /* Now load `achar' on top of the base outline. */
    error = CFF_Access_Element( &cff->charstrings_index, achar_index,
                                &charstring, &charstring_len );
    if ( !error )
    {
      error = CFF_Parse_CharStrings( decoder, charstring, charstring_len );

      if ( error )
        goto Exit;

      CFF_Forget_Element( &cff->charstrings_index, &charstring );
    }

    /* Restore the left side bearing and advance width */
    /* of the base character.                          */
    decoder->builder.left_bearing = left_bearing;
    decoder->builder.advance      = advance;

    /* Finally, move the accent. */
    if ( decoder->builder.load_points )
    {
      FT_Outline  dummy;


      dummy.n_points = (short)( base->n_points - n_base_points );
      dummy.points   = base->points   + n_base_points;

      FT_Outline_Translate( &dummy, adx, ady );
    }

  Exit:
    return error;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    CFF_Parse_CharStrings                                              */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Parses a given Type 2 charstrings program.                         */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    decoder         :: The current Type 1 decoder.                     */
  /*                                                                       */
  /* <Input>                                                               */
  /*    charstring_base :: The base of the charstring stream.              */
  /*                                                                       */
  /*    charstring_len  :: The length in bytes of the charstring stream.   */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  FT_LOCAL_DEF FT_Error
  CFF_Parse_CharStrings( CFF_Decoder*  decoder,
                         FT_Byte*      charstring_base,
                         FT_Int        charstring_len )
  {
    FT_Error           error;
    CFF_Decoder_Zone*  zone;
    FT_Byte*           ip;
    FT_Byte*           limit;
    CFF_Builder*       builder = &decoder->builder;
    FT_Pos             x, y;
    FT_Fixed           seed;
    FT_Fixed*          stack;

    T2_Hints_Funcs     hinter;


    /* set default width */
    decoder->num_hints  = 0;
    decoder->read_width = 1;

    /* compute random seed from stack address of parameter */
    seed = (FT_Fixed)(char*)&seed           ^
           (FT_Fixed)(char*)&decoder        ^
           (FT_Fixed)(char*)&charstring_base;
    seed = ( seed ^ ( seed >> 10 ) ^ ( seed >> 20 ) ) & 0xFFFF;
    if ( seed == 0 )
      seed = 0x7384;

    /* initialize the decoder */
    decoder->top  = decoder->stack;
    decoder->zone = decoder->zones;
    zone          = decoder->zones;
    stack         = decoder->top;

    hinter = (T2_Hints_Funcs) builder->hints_funcs;

    builder->path_begun = 0;

    zone->base           = charstring_base;
    limit = zone->limit  = charstring_base + charstring_len;
    ip    = zone->cursor = zone->base;

    error = CFF_Err_Ok;

    x = builder->pos_x;
    y = builder->pos_y;

    /* begin hints recording session, if any */
    if ( hinter )
      hinter->open( hinter->hints );

    /* now, execute loop */
    while ( ip < limit )
    {
      CFF_Operator  op;
      FT_Byte       v;


      /********************************************************************/
      /*                                                                  */
      /* Decode operator or operand                                       */
      /*                                                                  */
      v = *ip++;
      if ( v >= 32 || v == 28 )
      {
        FT_Int    shift = 16;
        FT_Int32  val;


        /* this is an operand, push it on the stack */
        if ( v == 28 )
        {
          if ( ip + 1 >= limit )
            goto Syntax_Error;
          val = (FT_Short)( ( (FT_Short)ip[0] << 8 ) | ip[1] );
          ip += 2;
        }
        else if ( v < 247 )
          val = (FT_Long)v - 139;
        else if ( v < 251 )
        {
          if ( ip >= limit )
            goto Syntax_Error;
          val = ( (FT_Long)v - 247 ) * 256 + *ip++ + 108;
        }
        else if ( v < 255 )
        {
          if ( ip >= limit )
            goto Syntax_Error;
          val = -( (FT_Long)v - 251 ) * 256 - *ip++ - 108;
        }
        else
        {
          if ( ip + 3 >= limit )
            goto Syntax_Error;
          val = ( (FT_Int32)ip[0] << 24 ) |
                ( (FT_Int32)ip[1] << 16 ) |
                ( (FT_Int32)ip[2] <<  8 ) |
                            ip[3];
          ip    += 4;
          shift  = 0;
        }
        if ( decoder->top - stack >= CFF_MAX_OPERANDS )
          goto Stack_Overflow;

        val           <<= shift;
        *decoder->top++ = val;

#ifdef FT_DEBUG_LEVEL_TRACE
        if ( !( val & 0xFFFF ) )
          FT_TRACE4(( " %d", (FT_Int32)( val >> 16 ) ));
        else
          FT_TRACE4(( " %.2f", val / 65536.0 ));
#endif

      }
      else
      {
        FT_Fixed*  args     = decoder->top;
        FT_Int     num_args = args - decoder->stack;
        FT_Int     req_args;


        /* find operator */
        op = cff_op_unknown;

        switch ( v )
        {
        case 1:
          op = cff_op_hstem;
          break;
        case 3:
          op = cff_op_vstem;
          break;
        case 4:
          op = cff_op_vmoveto;
          break;
        case 5:
          op = cff_op_rlineto;
          break;
        case 6:
          op = cff_op_hlineto;
          break;
        case 7:
          op = cff_op_vlineto;
          break;
        case 8:
          op = cff_op_rrcurveto;
          break;
        case 10:
          op = cff_op_callsubr;
          break;
        case 11:
          op = cff_op_return;
          break;
        case 12:
          {
            if ( ip >= limit )
              goto Syntax_Error;
            v = *ip++;

            switch ( v )
            {
            case 0:
              op = cff_op_dotsection;
              break;
            case 3:
              op = cff_op_and;
              break;
            case 4:
              op = cff_op_or;
              break;
            case 5:
              op = cff_op_not;
              break;
            case 8:
              op = cff_op_store;
              break;
            case 9:
              op = cff_op_abs;
              break;
            case 10:
              op = cff_op_add;
              break;
            case 11:
              op = cff_op_sub;
              break;
            case 12:
              op = cff_op_div;
              break;
            case 13:
              op = cff_op_load;
              break;
            case 14:
              op = cff_op_neg;
              break;
            case 15:
              op = cff_op_eq;
              break;
            case 18:
              op = cff_op_drop;
              break;
            case 20:
              op = cff_op_put;
              break;
            case 21:
              op = cff_op_get;
              break;
            case 22:
              op = cff_op_ifelse;