ftxgsub.c

神龙卡开发原代码

    if ( FILE_Seek( new_offset ) ||
         ( error = Load_Coverage( &csf2->Coverage, input ) ) != TT_Err_Ok )
      return error;
    (void)FILE_Seek( cur_offset );

    if ( ACCESS_Frame( 4L ) )
      goto Fail3;

    new_offset = GET_UShort() + base_offset;

    /* `SubClassSetCount' is the upper limit for class values, thus we
       read it now to make an additional safety check.                 */

    count = csf2->SubClassSetCount = GET_UShort();

    FORGET_Frame();

    cur_offset = FILE_Pos();
    if ( FILE_Seek( new_offset ) ||
         ( error = Load_ClassDefinition( &csf2->ClassDef, count,
                                         input ) ) != TT_Err_Ok )
      goto Fail3;
    (void)FILE_Seek( cur_offset );

    csf2->SubClassSet      = NULL;
    csf2->MaxContextLength = 0;

    if ( ALLOC_ARRAY( csf2->SubClassSet, count, TTO_SubClassSet ) )
      goto Fail2;

    scs = csf2->SubClassSet;

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

      new_offset = GET_UShort() + base_offset;

      FORGET_Frame();

      if ( new_offset != base_offset )      /* not a NULL offset */
      {
        cur_offset = FILE_Pos();
        if ( FILE_Seek( new_offset ) ||
             ( error = Load_SubClassSet( csf2, &scs[n],
                                         input ) ) != TT_Err_Ok )
          goto Fail1;
        (void)FILE_Seek( cur_offset );
      }
      else
      {
        /* we create a SubClassSet table with no entries */

        csf2->SubClassSet[n].SubClassRuleCount = 0;
        csf2->SubClassSet[n].SubClassRule      = NULL;
      }
    }

    return TT_Err_Ok;

  Fail1:
    for ( n = 0; n < count; n++ )
      Free_SubClassSet( &scs[n] );

    FREE( scs );

  Fail2:
    Free_ClassDefinition( &csf2->ClassDef );

  Fail3:
    Free_Coverage( &csf2->Coverage );
    return error;
  }


  static void  Free_Context2( TTO_ContextSubstFormat2*  csf2 )
  {
    UShort            n, count;

    TTO_SubClassSet*  scs;


    if ( csf2->SubClassSet )
    {
      count = csf2->SubClassSetCount;
      scs   = csf2->SubClassSet;

      for ( n = 0; n < count; n++ )
        Free_SubClassSet( &scs[n] );

      FREE( scs );
    }

    Free_ClassDefinition( &csf2->ClassDef );
    Free_Coverage( &csf2->Coverage );
  }


  /* ContextSubstFormat3 */

  static TT_Error  Load_ContextSubst3( TTO_ContextSubstFormat3*  csf3,
                                       PFace                     input )
  {
    DEFINE_LOAD_LOCALS( input->stream );

    UShort                  n, count;
    ULong                   cur_offset, new_offset, base_offset;

    TTO_Coverage*           c;
    TTO_SubstLookupRecord*  slr;


    base_offset = FILE_Pos() - 2L;

    if ( ACCESS_Frame( 4L ) )
      return error;

    csf3->GlyphCount = GET_UShort();
    csf3->SubstCount = GET_UShort();

    FORGET_Frame();

    csf3->Coverage = NULL;

    count = csf3->GlyphCount;

    if ( ALLOC_ARRAY( csf3->Coverage, count, TTO_Coverage ) )
      return error;

    c = csf3->Coverage;

    for ( n = 0; n < count; n++ )
    {
      if ( ACCESS_Frame( 2L ) )
        goto Fail2;

      new_offset = GET_UShort() + base_offset;

      FORGET_Frame();

      cur_offset = FILE_Pos();
      if ( FILE_Seek( new_offset ) ||
           ( error = Load_Coverage( &c[n], input ) ) != TT_Err_Ok )
        goto Fail2;
      (void)FILE_Seek( cur_offset );
    }

    csf3->SubstLookupRecord = NULL;

    count = csf3->SubstCount;

    if ( ALLOC_ARRAY( csf3->SubstLookupRecord, count,
                      TTO_SubstLookupRecord ) )
      goto Fail2;

    slr = csf3->SubstLookupRecord;

    if ( ACCESS_Frame( count * 4L ) )
      goto Fail1;

    for ( n = 0; n < count; n++ )
    {
      slr[n].SequenceIndex   = GET_UShort();
      slr[n].LookupListIndex = GET_UShort();
    }

    FORGET_Frame();

    return TT_Err_Ok;

  Fail1:
    FREE( slr );

  Fail2:
    for ( n = 0; n < count; n++ )
      Free_Coverage( &c[n] );

    FREE( c );
    return error;
  }


  static void  Free_Context3( TTO_ContextSubstFormat3*  csf3 )
  {
    UShort         n, count;

    TTO_Coverage*  c;


    FREE( csf3->SubstLookupRecord );

    if ( csf3->Coverage )
    {
      count = csf3->GlyphCount;
      c     = csf3->Coverage;

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

      FREE( c );
    }
  }


  /* ContextSubst */

  TT_Error  Load_ContextSubst( TTO_ContextSubst*  cs,
                               PFace              input )
  {
    DEFINE_LOAD_LOCALS( input->stream );


    if ( ACCESS_Frame( 2L ) )
      return error;

    cs->SubstFormat = GET_UShort();

    FORGET_Frame();

    switch ( cs->SubstFormat )
    {
    case 1:
      return Load_ContextSubst1( &cs->csf.csf1, input );

    case 2:
      return Load_ContextSubst2( &cs->csf.csf2, input );

    case 3:
      return Load_ContextSubst3( &cs->csf.csf3, input );

    default:
      return TTO_Err_Invalid_GSUB_SubTable_Format;
    }

    return TT_Err_Ok;               /* never reached */
  }


  void  Free_ContextSubst( TTO_ContextSubst*  cs )
  {
    switch ( cs->SubstFormat )
    {
    case 1:
      Free_Context1( &cs->csf.csf1 );
      break;

    case 2:
      Free_Context2( &cs->csf.csf2 );
      break;

    case 3:
      Free_Context3( &cs->csf.csf3 );
      break;
    }
  }


  static TT_Error  Lookup_ContextSubst1(
                     TTO_GSUBHeader*           gsub,
                     TTO_ContextSubstFormat1*  csf1,
                     TTO_GSUB_String*          in,
                     TTO_GSUB_String*          out,
                     UShort                    flags,
                     UShort                    context_length,
                     int                       nesting_level )
  {
    UShort           index, property;
    UShort           i, j, k, numsr;
    TT_Error         error;
    UShort*          s_in;

    TTO_SubRule*     sr;
    TTO_GDEFHeader*  gdef;


    gdef = gsub->gdef;

    if ( CHECK_Property( gdef, in->string[in->pos], flags, &property ) )
      return error;

    error = Coverage_Index( &csf1->Coverage, in->string[in->pos], &index );
    if ( error )
      return error;

    sr    = csf1->SubRuleSet[index].SubRule;
    numsr = csf1->SubRuleSet[index].SubRuleCount;

    for ( k = 0; k < numsr; k++ )
    {
      if ( context_length != 0xFFFF && context_length < sr[k].GlyphCount )
        continue;

      if ( in->pos + sr[k].GlyphCount > in->length )
        continue;                           /* context is too long */

      s_in = &in->string[in->pos];

      for ( i = 1, j = 1; i < sr[k].GlyphCount; i++, j++ )
      {
        while ( CHECK_Property( gdef, s_in[j], flags, &property ) )
        {
          if ( error && error != TTO_Err_Not_Covered )
            return error;

          if ( in->pos + j < in->length )
            j++;
          else
            break;
        }

        if ( s_in[j] != sr[k].Input[i - 1] )
          break;
      }

      if ( i == sr[k].GlyphCount )
        return Do_ContextSubst( gsub, sr[k].GlyphCount,
                                sr[k].SubstCount, sr[k].SubstLookupRecord,
                                in, out,
                                nesting_level );
    }

    return TTO_Err_Not_Covered;
  }


  static TT_Error  Lookup_ContextSubst2(
                     TTO_GSUBHeader*           gsub,
                     TTO_ContextSubstFormat2*  csf2,
                     TTO_GSUB_String*          in,
                     TTO_GSUB_String*          out,
                     UShort                    flags,
                     UShort                    context_length,
                     int                       nesting_level )
  {
    UShort             index, property;
    TT_Error           error;
    UShort             i, j, k, known_classes;

    UShort*            classes;
    UShort*            s_in;
    UShort*            cl;

    TTO_SubClassSet*   scs;
    TTO_SubClassRule*  sr;
    TTO_GDEFHeader*    gdef;


    gdef = gsub->gdef;

    if ( ALLOC_ARRAY( classes, csf2->MaxContextLength, UShort ) )
      return error;

    if ( CHECK_Property( gdef, in->string[in->pos], flags, &property ) )
      return error;

    /* Note: The coverage table in format 2 doesn't give an index into
             anything.  It just lets us know whether or not we need to
             do any lookup at all.                                     */

    error = Coverage_Index( &csf2->Coverage, in->string[in->pos], &index );
    if ( error )
      goto End;

    error = Get_Class( &csf2->ClassDef, in->string[in->pos],
                       &classes[0], NULL );
    if ( error )
      goto End;
    known_classes = 0;

    scs = &csf2->SubClassSet[classes[0]];
    if ( !scs )
    {
      error = TTO_Err_Invalid_GSUB_SubTable;
      goto End;
    }

    for ( k = 0; k < scs->SubClassRuleCount; k++ )
    {
      sr  = &scs->SubClassRule[k];

      if ( context_length != 0xFFFF && context_length < sr->GlyphCount )
        continue;

      if ( in->pos + sr->GlyphCount > in->length )
        continue;                           /* context is too long */

      s_in = &in->string[in->pos];
      cl   = sr->Class;

      /* Start at 1 because [0] is implied */

      for ( i = 1, j = 1; i < sr->GlyphCount; i++, j++ )
      {
        while ( CHECK_Property( gdef, s_in[j], flags, &property ) )
        {
          if ( error && error != TTO_Err_Not_Covered )
            return error;

          if ( in->pos + j < in->length )
            j++;
          else
            break;
        }

        if ( i > known_classes )
        {
          /* Keeps us from having to do this for each rule */

          error = Get_Class( &csf2->ClassDef, s_in[j], &classes[i], NULL );
          if ( error && error != TTO_Err_Not_Covered )
            return error;
          known_classes = i;
        }

        if ( cl[i - 1] != classes[i] )
          break;
      }

      if ( i == sr->GlyphCount )
      {
        error = Do_ContextSubst( gsub, sr->GlyphCount,
                                 sr->SubstCount, sr->SubstLookupRecord,
                                 in, out,
                                 nesting_level );
        goto End;
      }
    }

    error = TTO_Err_Not_Covered;

  End:
    FREE( classes );
    return error;
  }


  static TT_Error  Lookup_ContextSubst3(
                     TTO_GSUBHeader*           gsub,
                     TTO_ContextSubstFormat3*  csf3,
                     TTO_GSUB_String*          in,
                     TTO_GSUB_String*          out,
                     UShort                    flags,
                     UShort                    context_length,
                     int                       nesting_level )
  {
    TT_Error         error;
    UShort           index, i, j, property;
    UShort*          s_in;

    TTO_Coverage*    c;
    TTO_GDEFHeader*  gdef;


    gdef = gsub->gdef;

    if ( CHECK_Property( gdef, in->string[in->pos], flags, &property ) )
      return error;

    if ( context_length != 0xFFFF && context_length < csf3->GlyphCount )
      return TTO_Err_Not_Covered;

    if ( in->pos + csf3->GlyphCount > in->length )
      return TTO_Err_Not_Covered;         /* context is too long */

    s_in = &in->string[in->pos];
    c    = csf3->Coverage;

    for ( i = 1, j = 1; i < csf3->GlyphCount; i++, j++ )
    {
      while ( CHECK_Property( gdef, s_in[j], flags, &property ) )
      {
        if ( error && error != TTO_Err_Not_Covered )
          return error;

        if ( in->pos + j < in->length )
          j++;
        else
          return TTO_Err_Not_Covered;
      }

      error = Coverage_Index( &c[i], s_in[j], &index );
      if ( error )
        return error;
    }

    return Do_ContextSubst( gsub, csf3->GlyphCount,
                            csf3->SubstCount, csf3->SubstLookupRecord,
                            in, out,
                            nesting_level );
  }


  static TT_Error  Lookup_ContextSubst( TTO_GSUBHeader*    gsub,
                                        TTO_ContextSubst*  cs,
                                        TTO_GSUB_String*   in,
                                        TTO_GSUB_String*   out,
                                        UShort             flags,
                                        UShort             context_length,
                                        int                nesting_level )
  {
    switch ( cs->SubstFormat )
    {
    case 1:
      return Lookup_ContextSubst1( gsub, &cs->csf.csf1, in, out,
                                   flags, context_length, nesting_level );

    case 2:
      return Lookup_ContextSubst2( gsub, &cs->csf.csf2, in, out,
                                   flags, context_length, nesting_level );

    case 3:
      return Lookup_ContextSubst3( gsub, &cs->csf.csf3, in, out,
                                   flags, context_length, nesting_level );

    default:
      return TTO_Err_Invalid_GSUB_SubTable_Format;
    }

    return TT_Err_Ok;               /* never reached */
  }


  /* LookupType 6 */

  /* ChainSubRule */

  static TT_Error  Load_ChainSubRule( TTO_ChainSubRule*  csr,
                                      PFace              input )
  {
    DEFINE_LOAD_LOCALS( input->stream );

    UShort                  n, count;
    UShort*                 b;
    UShort*                 i;
    UShort*                 l;

    TTO_SubstLookupRecord*  slr;


    if ( ACCESS_Frame( 2L ) )
      return error;

    csr->BacktrackGlyphCount = GET_UShort();

    FORGET_Frame();

    csr->Backtrack = NULL;

    count = csr->BacktrackGlyphCount;

    if ( ALLOC_ARRAY( csr->Backtrack, count, UShort ) )
      return error;

    b = csr->Backtrack;

    if ( ACCESS_Frame( count * 2L ) )
      goto Fail4;

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

    FORGET_Frame();

    if ( ACCESS_Frame( 2L ) )
      goto Fail4;

    csr->InputGlyphCount = GET_UShort();

    FORGET_Frame();

    csr->Input = NULL;

    count = csr->InputGlyphCount - 1;  /* only InputGlyphCount - 1 elements */

    if ( ALLOC_ARRAY( csr->Input, count, UShort ) )
      goto Fail4;

    i = csr->Input;