ftxgsub.c

qt-x11-opensource-src-4.1.4.tar.gz源码

    for ( n = 0; n < count; n++ )
      a[n] = GET_UShort();

    FORGET_Frame();

    return TT_Err_Ok;
  }


  static void  Free_AlternateSet( TTO_AlternateSet*  as,
				  FT_Memory          memory )
  {
    FREE( as->Alternate );
  }


  /* AlternateSubstFormat1 */

  FT_Error  Load_AlternateSubst( TTO_AlternateSubst*  as,
                                 FT_Stream            stream )
  {
    FT_Error error;
    FT_Memory memory = stream->memory;

    FT_UShort          n = 0, m, count;
    FT_ULong           cur_offset, new_offset, base_offset;

    TTO_AlternateSet*  aset;


    base_offset = FILE_Pos();

    if ( ACCESS_Frame( 4L ) )
      return error;

    as->SubstFormat = GET_UShort();             /* should be 1 */
    new_offset      = GET_UShort() + base_offset;

    FORGET_Frame();

    cur_offset = FILE_Pos();
    if ( FILE_Seek( new_offset ) ||
         ( error = Load_Coverage( &as->Coverage, stream ) ) != TT_Err_Ok )
      return error;
    (void)FILE_Seek( cur_offset );

    if ( ACCESS_Frame( 2L ) )
      goto Fail2;

    count = as->AlternateSetCount = GET_UShort();

    FORGET_Frame();

    as->AlternateSet = NULL;

    if ( ALLOC_ARRAY( as->AlternateSet, count, TTO_AlternateSet ) )
      goto Fail2;

    aset = as->AlternateSet;

    for ( n = 0; n < count; n++ )
    {
      if ( ACCESS_Frame( 2L ) )
        goto Fail1;

      new_offset = GET_UShort() + base_offset;

      FORGET_Frame();

      cur_offset = FILE_Pos();
      if ( FILE_Seek( new_offset ) ||
           ( error = Load_AlternateSet( &aset[n], stream ) ) != TT_Err_Ok )
        goto Fail1;
      (void)FILE_Seek( cur_offset );
    }

    return TT_Err_Ok;

  Fail1:
    for ( m = 0; m < n; m++ )
      Free_AlternateSet( &aset[m], memory );

    FREE( aset );

  Fail2:
    Free_Coverage( &as->Coverage, memory );
    return error;
  }


  void  Free_AlternateSubst( TTO_AlternateSubst*  as,
			     FT_Memory            memory )
  {
    FT_UShort          n, count;

    TTO_AlternateSet*  aset;


    if ( as->AlternateSet )
    {
      count = as->AlternateSetCount;
      aset  = as->AlternateSet;

      for ( n = 0; n < count; n++ )
        Free_AlternateSet( &aset[n], memory );

      FREE( aset );
    }

    Free_Coverage( &as->Coverage, memory );
  }


  static FT_Error  Lookup_AlternateSubst( TTO_GSUBHeader*      gsub,
                                          TTO_AlternateSubst*  as,
					  OTL_Buffer           buffer,
                                          FT_UShort            flags,
                                          FT_UShort            context_length,
                                          TTO_GDEFHeader*      gdef )
  {
    FT_Error          error;
    FT_UShort         index, alt_index, property;

    TTO_AlternateSet  aset;


    if ( context_length != 0xFFFF && context_length < 1 )
      return TTO_Err_Not_Covered;

    if ( CHECK_Property( gdef, IN_CURITEM(), flags, &property ) )
      return error;

    error = Coverage_Index( &as->Coverage, IN_CURGLYPH(), &index );
    if ( error )
      return error;

    aset = as->AlternateSet[index];

    /* we use a user-defined callback function to get the alternate index */

    if ( gsub->altfunc )
      alt_index = (gsub->altfunc)( buffer->out_pos, IN_CURGLYPH(),
                                   aset.GlyphCount, aset.Alternate,
                                   gsub->data );
    else
      alt_index = 0;

    if ( ADD_Glyph( buffer, aset.Alternate[alt_index],
		    0xFFFF, 0xFFFF ) )
      return error;

    if ( gdef && gdef->NewGlyphClasses )
    {
      /* we inherit the old glyph class to the substituted glyph */

      error = Add_Glyph_Property( gdef, aset.Alternate[alt_index],
                                  property );
      if ( error && error != TTO_Err_Not_Covered )
        return error;
    }

    return TT_Err_Ok;
  }


  /* LookupType 4 */

  /* Ligature */

  static FT_Error  Load_Ligature( TTO_Ligature*  l,
                                  FT_Stream      stream )
  {
    FT_Error error;
    FT_Memory memory = stream->memory;

    FT_UShort n, count;
    FT_UShort*  c;


    if ( ACCESS_Frame( 4L ) )
      return error;

    l->LigGlyph       = GET_UShort();
    l->ComponentCount = GET_UShort();

    FORGET_Frame();

    l->Component = NULL;

    count = l->ComponentCount - 1;      /* only ComponentCount - 1 elements */

    if ( ALLOC_ARRAY( l->Component, count, FT_UShort ) )
      return error;

    c = l->Component;

    if ( ACCESS_Frame( count * 2L ) )
    {
      FREE( c );
      return error;
    }

    for ( n = 0; n < count; n++ )
      c[n] = GET_UShort();

    FORGET_Frame();

    return TT_Err_Ok;
  }


  static void  Free_Ligature( TTO_Ligature*  l,
			      FT_Memory      memory )
  {
    FREE( l->Component );
  }


  /* LigatureSet */

  static FT_Error  Load_LigatureSet( TTO_LigatureSet*  ls,
                                     FT_Stream         stream )
  {
    FT_Error error;
    FT_Memory memory = stream->memory;

    FT_UShort      n = 0, m, count;
    FT_ULong       cur_offset, new_offset, base_offset;

    TTO_Ligature*  l;


    base_offset = FILE_Pos();

    if ( ACCESS_Frame( 2L ) )
      return error;

    count = ls->LigatureCount = GET_UShort();

    FORGET_Frame();

    ls->Ligature = NULL;

    if ( ALLOC_ARRAY( ls->Ligature, count, TTO_Ligature ) )
      return error;

    l = ls->Ligature;

    for ( n = 0; n < count; n++ )
    {
      if ( ACCESS_Frame( 2L ) )
        goto Fail;

      new_offset = GET_UShort() + base_offset;

      FORGET_Frame();

      cur_offset = FILE_Pos();
      if ( FILE_Seek( new_offset ) ||
           ( error = Load_Ligature( &l[n], stream ) ) != TT_Err_Ok )
        goto Fail;
      (void)FILE_Seek( cur_offset );
    }

    return TT_Err_Ok;

  Fail:
    for ( m = 0; m < n; m++ )
      Free_Ligature( &l[m], memory );

    FREE( l );
    return error;
  }


  static void  Free_LigatureSet( TTO_LigatureSet*  ls,
				 FT_Memory         memory )
  {
    FT_UShort      n, count;

    TTO_Ligature*  l;


    if ( ls->Ligature )
    {
      count = ls->LigatureCount;
      l     = ls->Ligature;

      for ( n = 0; n < count; n++ )
        Free_Ligature( &l[n], memory );

      FREE( l );
    }
  }


  /* LigatureSubstFormat1 */

  FT_Error  Load_LigatureSubst( TTO_LigatureSubst*  ls,
                                FT_Stream           stream )
  {
    FT_Error error;
    FT_Memory memory = stream->memory;

    FT_UShort         n = 0, m, count;
    FT_ULong          cur_offset, new_offset, base_offset;

    TTO_LigatureSet*  lset;


    base_offset = FILE_Pos();

    if ( ACCESS_Frame( 4L ) )
      return error;

    ls->SubstFormat = GET_UShort();             /* should be 1 */
    new_offset      = GET_UShort() + base_offset;

    FORGET_Frame();

    cur_offset = FILE_Pos();
    if ( FILE_Seek( new_offset ) ||
         ( error = Load_Coverage( &ls->Coverage, stream ) ) != TT_Err_Ok )
      return error;
    (void)FILE_Seek( cur_offset );

    if ( ACCESS_Frame( 2L ) )
      goto Fail2;

    count = ls->LigatureSetCount = GET_UShort();

    FORGET_Frame();

    ls->LigatureSet = NULL;

    if ( ALLOC_ARRAY( ls->LigatureSet, count, TTO_LigatureSet ) )
      goto Fail2;

    lset = ls->LigatureSet;

    for ( n = 0; n < count; n++ )
    {
      if ( ACCESS_Frame( 2L ) )
        goto Fail1;

      new_offset = GET_UShort() + base_offset;

      FORGET_Frame();

      cur_offset = FILE_Pos();
      if ( FILE_Seek( new_offset ) ||
           ( error = Load_LigatureSet( &lset[n], stream ) ) != TT_Err_Ok )
        goto Fail1;
      (void)FILE_Seek( cur_offset );
    }

    return TT_Err_Ok;

  Fail1:
    for ( m = 0; m < n; m++ )
      Free_LigatureSet( &lset[m], memory );

    FREE( lset );

  Fail2:
    Free_Coverage( &ls->Coverage, memory );
    return error;
  }


  void  Free_LigatureSubst( TTO_LigatureSubst*  ls,
			    FT_Memory           memory )
  {
    FT_UShort         n, count;

    TTO_LigatureSet*  lset;


    if ( ls->LigatureSet )
    {
      count = ls->LigatureSetCount;
      lset  = ls->LigatureSet;

      for ( n = 0; n < count; n++ )
        Free_LigatureSet( &lset[n], memory );

      FREE( lset );
    }

    Free_Coverage( &ls->Coverage, memory );
  }


  static FT_Error  Lookup_LigatureSubst( TTO_LigatureSubst*  ls,
					 OTL_Buffer          buffer,
                                         FT_UShort           flags,
                                         FT_UShort           context_length,
                                         TTO_GDEFHeader*     gdef )
  {
    FT_UShort      index, property;
    FT_Error       error;
    FT_UShort      numlig, i, j, is_mark, first_is_mark = FALSE;
    FT_UShort*     c;

    TTO_Ligature*  lig;


    if ( CHECK_Property( gdef, IN_CURITEM(), flags, &property ) )
      return error;

    if ( property == TTO_MARK || property & IGNORE_SPECIAL_MARKS )
      first_is_mark = TRUE;

    error = Coverage_Index( &ls->Coverage, IN_CURGLYPH(), &index );
    if ( error )
      return error;

    if ( index >= ls->LigatureSetCount )
       return TTO_Err_Invalid_GSUB_SubTable;

    lig = ls->LigatureSet[index].Ligature;

    for ( numlig = ls->LigatureSet[index].LigatureCount;
          numlig;
          numlig--, lig++ )
    {
      if ( buffer->in_pos + lig->ComponentCount > buffer->in_length )
        goto next_ligature;               /* Not enough glyphs in input */

      c    = lig->Component;

      is_mark = first_is_mark;

      if ( context_length != 0xFFFF && context_length < lig->ComponentCount )
        break;

      for ( i = 1, j = buffer->in_pos + 1; i < lig->ComponentCount; i++, j++ )
      {
        while ( CHECK_Property( gdef, IN_ITEM( j ), flags, &property ) )
        {
          if ( error && error != TTO_Err_Not_Covered )
            return error;

          if ( j + lig->ComponentCount - i == (FT_Int)buffer->in_length )
	    goto next_ligature;
	  j++;
        }

        if ( !( property == TTO_MARK || property & IGNORE_SPECIAL_MARKS ) )
          is_mark = FALSE;

        if ( IN_GLYPH( j ) != c[i - 1] )
	  goto next_ligature;
      }

      if ( gdef && gdef->NewGlyphClasses )
      {
	/* this is just a guess ... */

	error = Add_Glyph_Property( gdef, lig->LigGlyph,
				    is_mark ? TTO_MARK : TTO_LIGATURE );
	if ( error && error != TTO_Err_Not_Covered )
	  return error;
      }

      if ( j == buffer->in_pos + i ) /* No input glyphs skipped */
      {
	/* We don't use a new ligature ID if there are no skipped
	   glyphs and the ligature already has an ID.             */

	if ( IN_LIGID( buffer->in_pos ) )
	{
	  if ( ADD_String( buffer, i, 1, &lig->LigGlyph,
			  0xFFFF, 0xFFFF ) )
	    return error;
	}
	else
	{
	  FT_UShort ligID = otl_buffer_allocate_ligid( buffer );
	  if ( ADD_String( buffer, i, 1, &lig->LigGlyph,
			  0xFFFF, ligID ) )
	    return error;
	}
      }
      else
      {
	FT_UShort ligID = otl_buffer_allocate_ligid( buffer );
	if ( ADD_Glyph( buffer, lig->LigGlyph,
			0xFFFF, ligID ) )
	  return error;

	/* Now we must do a second loop to copy the skipped glyphs to
	   `out' and assign component values to it.  We start with the
	   glyph after the first component.  Glyphs between component
	   i and i+1 belong to component i.  Together with the ligID
	   value it is later possible to check whether a specific
	   component value really belongs to a given ligature.         */

	for ( i = 0; i < lig->ComponentCount - 1; i++ )
	{
	  while ( CHECK_Property( gdef, IN_CURITEM(),
				  flags, &property ) )
	    if ( ADD_Glyph( buffer, IN_CURGLYPH(),
			    i, ligID ) )
	      return error;

	  (buffer->in_pos)++;
	}
      }

      return TT_Err_Ok;

    next_ligature:
      ;
    }

    return TTO_Err_Not_Covered;
  }


  /* Do the actual substitution for a context substitution (either format
     5 or 6).  This is only called after we've determined that the input
     matches the subrule.                                                 */

  static FT_Error  Do_ContextSubst( TTO_GSUBHeader*         gsub,
                                    FT_UShort               GlyphCount,
                                    FT_UShort               SubstCount,
                                    TTO_SubstLookupRecord*  subst,
				    OTL_Buffer              buffer,
                                    int                     nesting_level )
  {
    FT_Error  error;
    FT_UShort i, old_pos;


    i = 0;

    while ( i < GlyphCount )
    {
      if ( SubstCount && i == subst->SequenceIndex )
      {
        old_pos = buffer->in_pos;

        /* Do a substitution */

        error = GSub_Do_Glyph_Lookup( gsub, subst->LookupListIndex, buffer,
                                      GlyphCount, nesting_level );

        subst++;
        SubstCount--;
        i += buffer->in_pos - old_pos;

        if ( error == TTO_Err_Not_Covered )
        {
          /* XXX "can't happen" -- but don't count on it */

          if ( ADD_Glyph( buffer, IN_CURGLYPH(),
			  0xFFFF, 0xFFFF ) )
            return error;
          i++;
        }
        else if ( error )
          return error;
      }
      else
      {
        /* No substitution for this index */

        if ( ADD_Glyph( buffer, IN_CURGLYPH(),
			0xFFFF, 0xFFFF ) )
          return error;
        i++;
      }
    }

    return TT_Err_Ok;