gxvkern.c

奇趣公司比较新的qt/emd版本

                            + GXV_KERN_FMT2_DATA( offset_max[GXV_KERN_CLS_R] )
                            - GXV_KERN_FMT2_DATA( array ),
                          "array", odtect );

    gxv_odtect_validate( odtect, valid );

    GXV_EXIT;
  }


  /* ============================= format 3 ============================== */

  static void
  gxv_kern_subtable_fmt3_validate( FT_Bytes       table,
                                   FT_Bytes       limit,
                                   GXV_Validator  valid )
  {
    FT_Bytes   p = table + GXV_KERN_SUBTABLE_HEADER_SIZE;
    FT_UShort  glyphCount;
    FT_Byte    kernValueCount;
    FT_Byte    leftClassCount;
    FT_Byte    rightClassCount;
    FT_Byte    flags;


    GXV_NAME_ENTER( "kern subtable format 3" );

    GXV_LIMIT_CHECK( 2 + 1 + 1 + 1 + 1 );
    glyphCount      = FT_NEXT_USHORT( p );
    kernValueCount  = FT_NEXT_BYTE( p );
    leftClassCount  = FT_NEXT_BYTE( p );
    rightClassCount = FT_NEXT_BYTE( p );
    flags           = FT_NEXT_BYTE( p );

    if ( valid->face->num_glyphs != glyphCount )
    {
      GXV_TRACE(( "maxGID=%d, but glyphCount=%d\n",
                  valid->face->num_glyphs, glyphCount ));
      if ( valid->root->level >= FT_VALIDATE_PARANOID )
        FT_INVALID_GLYPH_ID;
    }

    /*
     * just skip kernValue[kernValueCount]
     */
    GXV_LIMIT_CHECK( 2 * kernValueCount );
    p += 2 * kernValueCount;

    /*
     * check leftClass[gid] < leftClassCount
     */
    {
      FT_Byte  min, max;


      GXV_LIMIT_CHECK( glyphCount );
      gxv_array_getlimits_byte( p, p + glyphCount, &min, &max, valid );
      p += valid->subtable_length;

      if ( leftClassCount < max )
        FT_INVALID_DATA;
    }

    /*
     * check rightClass[gid] < rightClassCount
     */
    {
      FT_Byte  min, max;


      GXV_LIMIT_CHECK( glyphCount );
      gxv_array_getlimits_byte( p, p + glyphCount, &min, &max, valid );
      p += valid->subtable_length;

      if ( rightClassCount < max )
        FT_INVALID_DATA;
    }

    /*
     * check kernIndex[i, j] < kernValueCount
     */
    {
      FT_UShort  i, j;


      for ( i = 0; i < leftClassCount; i++ )
      {
        for ( j = 0; j < rightClassCount; j++ )
        {
          GXV_LIMIT_CHECK( 1 );
          if ( kernValueCount < FT_NEXT_BYTE( p ) )
            FT_INVALID_OFFSET;
        }
      }
    }

    valid->subtable_length = p - table;

    GXV_EXIT;
  }


  static FT_Bool
  gxv_kern_coverage_new_apple_validate( FT_UShort      coverage,
                                        FT_UShort*     format,
                                        GXV_Validator  valid )
  {
    /* new Apple-dialect */
    FT_Bool  kernVertical;
    FT_Bool  kernCrossStream;
    FT_Bool  kernVariation;

    FT_UNUSED( valid );


    /* reserved bits = 0 */
    if ( coverage & 0x1FFC )
      return 0;

    kernVertical    = FT_BOOL( ( coverage >> 15 ) & 1 );
    kernCrossStream = FT_BOOL( ( coverage >> 14 ) & 1 );
    kernVariation   = FT_BOOL( ( coverage >> 13 ) & 1 );

    *format = (FT_UShort)( coverage & 0x0003 );

    GXV_TRACE(( "new Apple-dialect: "
                "horizontal=%d, cross-stream=%d, variation=%d, format=%d\n",
                 !kernVertical, kernCrossStream, kernVariation, *format ));

    GXV_TRACE(( "kerning values in Apple format subtable are ignored\n" ));

    return 1;
  }


  static FT_Bool
  gxv_kern_coverage_classic_apple_validate( FT_UShort      coverage,
                                            FT_UShort*     format,
                                            GXV_Validator  valid )
  {
    /* classic Apple-dialect */
    FT_Bool  horizontal;
    FT_Bool  cross_stream;


    /* check expected flags, but don't check if MS-dialect is impossible */
    if ( !( coverage & 0xFD00 ) && KERN_ALLOWS_MS( valid ) )
      return 0;

    /* reserved bits = 0 */
    if ( coverage & 0x02FC )
      return 0;

    horizontal   = FT_BOOL( ( coverage >> 15 ) & 1 );
    cross_stream = FT_BOOL( ( coverage >> 13 ) & 1 );

    *format = (FT_UShort)( coverage & 0x0003 );

    GXV_TRACE(( "classic Apple-dialect: "
                "horizontal=%d, cross-stream=%d, format=%d\n",
                 horizontal, cross_stream, *format ));

    /* format 1 requires GX State Machine, too new for classic */
    if ( *format == 1 )
      return 0;

    GXV_TRACE(( "kerning values in Apple format subtable are ignored\n" ));

    return 1;
  }


  static FT_Bool
  gxv_kern_coverage_classic_microsoft_validate( FT_UShort      coverage,
                                                FT_UShort*     format,
                                                GXV_Validator  valid )
  {
    /* classic Microsoft-dialect */
    FT_Bool  horizontal;
    FT_Bool  minimum;
    FT_Bool  cross_stream;
    FT_Bool  override;

    FT_UNUSED( valid );


    /* reserved bits = 0 */
    if ( coverage & 0xFDF0 )
      return 0;

    horizontal   = FT_BOOL(   coverage        & 1 );
    minimum      = FT_BOOL( ( coverage >> 1 ) & 1 );
    cross_stream = FT_BOOL( ( coverage >> 2 ) & 1 );
    override     = FT_BOOL( ( coverage >> 3 ) & 1 );

    *format = (FT_UShort)( ( coverage >> 8 ) & 0x0003 );

    GXV_TRACE(( "classic Microsoft-dialect: "
                "horizontal=%d, minimum=%d, cross-stream=%d, "
                "override=%d, format=%d\n",
                horizontal, minimum, cross_stream, override, *format ));

    if ( *format == 2 )
      GXV_TRACE((
        "kerning values in Microsoft format 2 subtable are ignored\n" ));

    return 1;
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                            MAIN                               *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  static GXV_kern_Dialect
  gxv_kern_coverage_validate( FT_UShort      coverage,
                              FT_UShort*     format,
                              GXV_Validator  valid )
  {
    GXV_kern_Dialect  result = KERN_DIALECT_UNKNOWN;


    GXV_NAME_ENTER( "validating coverage" );

    GXV_TRACE(( "interprete coverage 0x%04x by Apple style\n", coverage ));

    if ( KERN_IS_NEW( valid ) )
    {
      if ( gxv_kern_coverage_new_apple_validate( coverage,
                                                 format,
                                                 valid ) )
      {
        result = KERN_DIALECT_APPLE;
        goto Exit;
      }
    }

    if ( KERN_IS_CLASSIC( valid ) && KERN_ALLOWS_APPLE( valid ) )
    {
      if ( gxv_kern_coverage_classic_apple_validate( coverage,
                                                     format,
                                                     valid ) )
      {
        result = KERN_DIALECT_APPLE;
        goto Exit;
      }
    }

    if ( KERN_IS_CLASSIC( valid ) && KERN_ALLOWS_MS( valid ) )
    {
      if ( gxv_kern_coverage_classic_microsoft_validate( coverage,
                                                         format,
                                                         valid ) )
      {
        result = KERN_DIALECT_MS;
        goto Exit;
      }
    }

    GXV_TRACE(( "cannot interprete coverage, broken kern subtable\n" ));

  Exit:
    GXV_EXIT;
    return result;
  }


  static void
  gxv_kern_subtable_validate( FT_Bytes       table,
                              FT_Bytes       limit,
                              GXV_Validator  valid )
  {
    FT_Bytes   p = table;
    FT_UShort  version = 0;    /* MS only: subtable version, unused */
    FT_ULong   length;         /* MS: 16bit, Apple: 32bit*/
    FT_UShort  coverage;
    FT_UShort  tupleIndex = 0; /* Apple only */
    FT_UShort  u16[2];
    FT_UShort  format = 255;   /* subtable format */


    GXV_NAME_ENTER( "kern subtable" );

    GXV_LIMIT_CHECK( 2 + 2 + 2 );
    u16[0]   = FT_NEXT_USHORT( p ); /* Apple: length_hi MS: version */
    u16[1]   = FT_NEXT_USHORT( p ); /* Apple: length_lo MS: length */
    coverage = FT_NEXT_USHORT( p );

    switch ( gxv_kern_coverage_validate( coverage, &format, valid ) )
    {
    case KERN_DIALECT_MS:
      version    = u16[0];
      length     = u16[1];
      tupleIndex = 0;
      GXV_TRACE(( "Subtable version = %d\n", version ));
      GXV_TRACE(( "Subtable length = %d\n", length ));
      break;

    case KERN_DIALECT_APPLE:
      version    = 0;
      length     = ( u16[0] << 16 ) + u16[1];
      tupleIndex = 0;
      GXV_TRACE(( "Subtable length = %d\n", length ));

      if ( KERN_IS_NEW( valid ) )
      {
        GXV_LIMIT_CHECK( 2 );
        tupleIndex = FT_NEXT_USHORT( p );
        GXV_TRACE(( "Subtable tupleIndex = %d\n", tupleIndex ));
      }
      break;

    default:
      length = u16[1];
      GXV_TRACE(( "cannot detect subtable dialect, "
                  "just skip %d byte\n", length ));
      goto Exit;
    }

    /* formats 1, 2, 3 require the position of the start of this subtable */
    if ( format == 0 )
      gxv_kern_subtable_fmt0_validate( table, table + length, valid );
    else if ( format == 1 )
      gxv_kern_subtable_fmt1_validate( table, table + length, valid );
    else if ( format == 2 )
      gxv_kern_subtable_fmt2_validate( table, table + length, valid );
    else if ( format == 3 )
      gxv_kern_subtable_fmt3_validate( table, table + length, valid );
    else
      FT_INVALID_DATA;

  Exit:
    valid->subtable_length = length;
    GXV_EXIT;
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                         kern TABLE                            *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  static void
  gxv_kern_validate_generic( FT_Bytes          table,
                             FT_Face           face,
                             FT_Bool           classic_only,
                             GXV_kern_Dialect  dialect_request,
                             FT_Validator      ftvalid )
  {
    GXV_ValidatorRec   validrec;
    GXV_Validator      valid = &validrec;

    GXV_kern_DataRec   kernrec;
    GXV_kern_Data      kern = &kernrec;

    FT_Bytes           p     = table;
    FT_Bytes           limit = 0;

    FT_ULong           nTables = 0;
    FT_UInt            i;


    valid->root       = ftvalid;
    valid->table_data = kern;
    valid->face       = face;

    FT_TRACE3(( "validating `kern' table\n" ));
    GXV_INIT;
    KERN_DIALECT( valid ) = dialect_request;

    GXV_LIMIT_CHECK( 2 );
    GXV_KERN_DATA( version ) = (GXV_kern_Version)FT_NEXT_USHORT( p );
    GXV_TRACE(( "version 0x%04x (higher 16bit)\n",
                GXV_KERN_DATA( version ) ));

    if ( 0x0001 < GXV_KERN_DATA( version ) )
      FT_INVALID_FORMAT;
    else if ( KERN_IS_CLASSIC( valid ) )
    {
      GXV_LIMIT_CHECK( 2 );
      nTables = FT_NEXT_USHORT( p );
    }
    else if ( KERN_IS_NEW( valid ) )
    {
      if ( classic_only )
        FT_INVALID_FORMAT;

      if ( 0x0000 != FT_NEXT_USHORT( p ) )
        FT_INVALID_FORMAT;

      GXV_LIMIT_CHECK( 4 );
      nTables = FT_NEXT_ULONG( p );
    }

    for ( i = 0; i < nTables; i++ )
    {
      GXV_TRACE(( "validating subtable %d/%d\n", i, nTables ));
      /* p should be 32bit-aligned? */
      gxv_kern_subtable_validate( p, 0, valid );
      p += valid->subtable_length;
    }

    FT_TRACE4(( "\n" ));
  }


  FT_LOCAL_DEF( void )
  gxv_kern_validate( FT_Bytes      table,
                     FT_Face       face,
                     FT_Validator  ftvalid )
  {
    gxv_kern_validate_generic( table, face, 0, KERN_DIALECT_ANY, ftvalid );
  }


  FT_LOCAL_DEF( void )
  gxv_kern_validate_classic( FT_Bytes      table,
                             FT_Face       face,
                             FT_Int        dialect_flags,
                             FT_Validator  ftvalid )
  {
    GXV_kern_Dialect  dialect_request;


    dialect_request = (GXV_kern_Dialect)dialect_flags;
    gxv_kern_validate_generic( table, face, 1, dialect_request, ftvalid );
  }


/* END */