ttload.c

神龙卡开发原代码

      if ( n < 0 )
      {
        /* Set the number_Of_VMetrics to 0! */
        PTRACE2(( "  no vertical header in file.\n" ));
        face->verticalHeader.number_Of_VMetrics = 0;
        return TT_Err_Ok;
      }

      num_longs = face->verticalHeader.number_Of_VMetrics;
      longs     = (PLongMetrics*)&face->verticalHeader.long_metrics;
      shorts    = (PShortMetrics*)&face->verticalHeader.short_metrics;
    }
    else
    {
      if ( ( n = TT_LookUp_Table( face, TTAG_hmtx ) ) < 0 )
      {
        PERROR(( "!! No Horizontal metrics in file !!\n" ));
        return TT_Err_Hmtx_Table_Missing;
      }

      num_longs = face->horizontalHeader.number_Of_HMetrics;
      longs     = (PLongMetrics*)&face->horizontalHeader.long_metrics;
      shorts    = (PShortMetrics*)&face->horizontalHeader.short_metrics;
    }

    /* never trust derived values! */

    num_shorts         = face->maxProfile.numGlyphs - num_longs;
    num_shorts_checked = ( face->dirTables[n].Length - num_longs * 4 ) / 2;

    if ( num_shorts < 0 )            /* sanity check */
    {
      PERROR(( "!! more metrics than glyphs!\n" ));
      if ( vertical )
        return TT_Err_Invalid_Vert_Metrics;
      else
        return TT_Err_Invalid_Horiz_Metrics;
    }

    if ( ALLOC_ARRAY( *longs,  num_longs,  TLongMetrics  ) ||
         ALLOC_ARRAY( *shorts, num_shorts, TShortMetrics ) )
      return error;

    if ( FILE_Seek( face->dirTables[n].Offset )   ||
         ACCESS_Frame( face->dirTables[n].Length ) )
      return error;

    long_metric = *longs;
    for ( n = 0; n < num_longs; n++ )
    {
      long_metric->advance = GET_UShort();
      long_metric->bearing = GET_Short();
      long_metric++;
    }

    /* do we have an inconsistent number of metric values? */

    if ( num_shorts > num_shorts_checked )
    {
      for ( n = 0; n < num_shorts_checked; n++ )
        (*shorts)[n] = GET_Short();

      /* we fill up the missing left side bearings with the    */
      /* last valid value. Since this will occur for buggy CJK */
      /* fonts usually, nothing serious will happen.           */

      for ( n = num_shorts_checked; n < num_shorts; n++ )
        (*shorts)[n] = (*shorts)[num_shorts_checked - 1];
    }
    else
    {
      for ( n = 0; n < num_shorts; n++ )
        (*shorts)[n] = GET_Short();
    }

    FORGET_Frame();

    PTRACE2(( "loaded\n" ));
    return TT_Err_Ok;
  }


/*******************************************************************
 *
 *  Function    : Load_TrueType_Metrics_Header
 *
 *  Description : Loads either the "hhea" or "vhea" table in memory
 *
 *  Input  :  face       face table to look for
 *            vertical   a boolean.  When set, queries the optional
 *                       "vhea" table.  Otherwise, load the mandatory
 *                       "hhea" horizontal header.
 *
 *  Output :  Error code.
 *
 *  Note : This function now loads the corresponding metrics table
 *         (either hmtx or vmtx) and attaches it to the header.
 *
 ******************************************************************/

  LOCAL_FUNC
  TT_Error  Load_TrueType_Metrics_Header( PFace  face,
                                          Bool   vertical )
  {
    DEFINE_LOCALS;

    Long  i;

    TT_Horizontal_Header*  header;


    PTRACE2(( vertical ? "Vertical header" : "Horizontal header " ));

    if ( vertical )
    {
      face->verticalInfo = 0;

      /* The vertical header table is optional, so return quietly if */
      /* we don't find it..                                          */
      if ( ( i = TT_LookUp_Table( face, TTAG_vhea ) ) < 0 )
        return TT_Err_Ok;

      face->verticalInfo = 1;
      header = (TT_Horizontal_Header*)&face->verticalHeader;
    }
    else
    {
      /* The orizontal header is mandatory, return an error if we */
      /* don't find it.                                           */
      if ( ( i = TT_LookUp_Table( face, TTAG_hhea ) ) < 0 )
        return TT_Err_Horiz_Header_Missing;

      header = &face->horizontalHeader;
    }

    if ( FILE_Seek( face->dirTables[i].Offset ) ||
         ACCESS_Frame( 36L ) )
      return error;

    header->Version   = GET_ULong();
    header->Ascender  = GET_Short();
    header->Descender = GET_Short();
    header->Line_Gap  = GET_Short();

    header->advance_Width_Max = GET_UShort();

    header->min_Left_Side_Bearing  = GET_Short();
    header->min_Right_Side_Bearing = GET_Short();
    header->xMax_Extent            = GET_Short();
    header->caret_Slope_Rise       = GET_Short();
    header->caret_Slope_Run        = GET_Short();

    header->Reserved0 = GET_Short();    /* this is caret_Offset for
                                           vertical headers */
    header->Reserved1 = GET_Short();
    header->Reserved2 = GET_Short();
    header->Reserved3 = GET_Short();
    header->Reserved4 = GET_Short();

    header->metric_Data_Format = GET_Short();
    header->number_Of_HMetrics = GET_UShort();

    FORGET_Frame();

    header->long_metrics  = NULL;
    header->short_metrics = NULL;

    PTRACE2(( "loaded\n" ));

    /* Now try to load the corresponding metrics */

    return Load_TrueType_Metrics( face, vertical );
  }


/*******************************************************************
 *
 *  Function    :  Load_TrueType_Locations
 *
 *  Description :  Loads the location table into face table.
 *
 *  Input  :  face     face table to look for
 *
 *  Output :  Error code.
 *
 *  NOTE:
 *    The Font Header *must* be loaded in the leading segment
 *    calling this function.
 *
 ******************************************************************/

  LOCAL_FUNC
  TT_Error  Load_TrueType_Locations( PFace  face )
  {
    DEFINE_LOCALS;

    Long   n, limit;
    Short  LongOffsets;


    PTRACE2(( "Locations " ));

    LongOffsets = face->fontHeader.Index_To_Loc_Format;

    if ( ( n = TT_LookUp_Table( face, TTAG_loca ) ) < 0 )
      return TT_Err_Locations_Missing;

    if ( FILE_Seek( face->dirTables[n].Offset ) )
      return error;

    if ( LongOffsets != 0 )
    {
      face->numLocations = face->dirTables[n].Length >> 2;

      PTRACE2(( "(32 bit offsets): %12lu ",
                   face->numLocations ));

      if ( ALLOC_ARRAY( face->glyphLocations,
                        face->numLocations,
                        Long ) )
        return error;

      if ( ACCESS_Frame( face->numLocations * 4L ) )
        return error;

      limit = face->numLocations;

      for ( n = 0; n < limit; n++ )
        face->glyphLocations[n] = GET_Long();

      FORGET_Frame();
    }
    else
    {
      face->numLocations = face->dirTables[n].Length >> 1;

      PTRACE2(( "(16 bit offsets): %12lu ",
                   face->numLocations ));

      if ( ALLOC_ARRAY( face->glyphLocations,
                        face->numLocations,
                        Long ) )
        return error;

      if ( ACCESS_Frame( face->numLocations * 2L ) )
        return error;

      limit = face->numLocations;

      for ( n = 0; n < limit; n++ )
        face->glyphLocations[n] =
          (Long)((ULong)GET_UShort() * 2);

      FORGET_Frame();
    }

    PTRACE2(( "loaded\n" ));

    return TT_Err_Ok;
  }


/*******************************************************************
 *
 *  Function    :  Load_TrueType_Names
 *
 *  Description :  Loads the name table into face table.
 *
 *  Input  :  face     face table to look for
 *
 *  Output :  Error code.
 *
 ******************************************************************/

  LOCAL_FUNC
  TT_Error  Load_TrueType_Names( PFace  face )
  {
    DEFINE_LOCALS;

    UShort  i, bytes;
    Long    n;
    PByte   storage;

    TName_Table*  names;
    TNameRec*     namerec;


    PTRACE2(( "Names " ));

    if ( ( n = TT_LookUp_Table( face, TTAG_name ) ) < 0 )
    {
      /* The name table is required so indicate failure. */
      PTRACE2(( "is missing!\n" ));

      return TT_Err_Name_Table_Missing;
    }

    /* Seek to the beginning of the table and check the frame access. */
    /* The names table has a 6 byte header.                           */
    if ( FILE_Seek( face->dirTables[n].Offset ) ||
         ACCESS_Frame( 6L ) )
      return error;

    names = &face->nameTable;

    /* Load the initial names data. */
    names->format         = GET_UShort();
    names->numNameRecords = GET_UShort();
    names->storageOffset  = GET_UShort();

    FORGET_Frame();

    /* Allocate the array of name records. */
    if ( ALLOC_ARRAY( names->names,
                      names->numNameRecords,
                      TNameRec )                    ||
         ACCESS_Frame( names->numNameRecords * 12L ) )
    {
      names->numNameRecords = 0;
      goto Fail;
    }

    /* Load the name records and determine how much storage is needed */
    /* to hold the strings themselves.                                */

    for ( i = bytes = 0; i < names->numNameRecords; i++ )
    {
      namerec = names->names + i;
      namerec->platformID   = GET_UShort();
      namerec->encodingID   = GET_UShort();
      namerec->languageID   = GET_UShort();
      namerec->nameID       = GET_UShort();
      namerec->stringLength = GET_UShort();
      namerec->stringOffset = GET_UShort();

#if 0
      /* check the ids */
      if ( namerec->platformID <= 3 )
      {
#endif
        /* this test takes care of 'holes' in the names tables, as */
        /* reported by Erwin                                       */
        if ( (namerec->stringOffset + namerec->stringLength) > bytes )
          bytes = namerec->stringOffset + namerec->stringLength;
#if 0
      }
#endif
    }

    FORGET_Frame();

    /* Allocate storage for the strings if they exist. */

    names->storage = NULL;

    if ( bytes > 0 )
    {
      if ( ALLOC( storage, bytes ) ||
           FILE_Read_At( face->dirTables[n].Offset + names->storageOffset,
                         (void*)storage,
                         bytes ) )
        goto Fail_Storage;

      names->storage = storage;

      /* Go through and assign the string pointers to the name records. */

      for ( i = 0; i < names->numNameRecords; i++ )
      {
        namerec = names->names + i;
        namerec->string = storage + names->names[i].stringOffset;

/* It is possible (but rather unlikely) that a new platform ID will be */
/* added by Apple, so we can't rule out IDs > 3.                       */

#if 0
        if ( namerec->platformID <= 3 )
          namerec->string = storage + names->names[i].stringOffset;
        else
        {
          namerec->string       = NULL;
          namerec->stringLength = 0;
        }
#endif
      }
    }

#ifdef DEBUG_LEVEL_TRACE

    for ( i = 0; i < names->numNameRecords; i++ )
    {
      int  j;


      PTRACE2(( "%d %d %x %d ",
                   names->names[i].platformID,
                   names->names[i].encodingID,
                   names->names[i].languageID,
                   names->names[i].nameID ));

      /* I know that M$ encoded strings are Unicode,            */
      /* but this works reasonable well for debugging purposes. */
      for ( j = 0; j < names->names[i].stringLength; j++ )
      {
        if (names->names[i].string)
        {
          Char  c = *(names->names[i].string + j);


          if ( (Byte)c < 128 )
            PTRACE2(( "%c", c ));
        }
      }

      PTRACE2(( "\n" ));
    }

#endif /* DEBUG_LEVEL_TRACE */

    PTRACE2(( "loaded\n" ));
    return TT_Err_Ok;

  Fail_Storage:
    FREE( storage );

  Fail:
    Free_TrueType_Names( face );
    return error;
  }


/*******************************************************************
 *
 *  Function    :  Free_TrueType_Names
 *
 *  Description :  Frees a name table.
 *
 *  Input  :  face     face table to look for
 *
 *  Output :  TT_Err_Ok.
 *
 ******************************************************************/

  LOCAL_FUNC
  TT_Error  Free_TrueType_Names( PFace  face )
  {
    TName_Table*  names = &face->nameTable;


    /* free strings table */
    FREE( names->names );

    /* free strings storage */
    FREE( names->storage );

    names->numNameRecords = 0;
    names->format         = 0;
    names->storageOffset  = 0;

    return TT_Err_Ok;
  }


/*******************************************************************
 *
 *  Function    :  Load_TrueType_CVT
 *
 *  Description :  Loads cvt table into resident table.
 *
 *  Input  :  face     face table to look for
 *
 *  Output :  Error code.
 *
 ******************************************************************/

  LOCAL_FUNC
  TT_Error  Load_TrueType_CVT( PFace  face )
  {
    DEFINE_LOCALS;

    Long  n, limit;


    PTRACE2(( "CVT " ));

    if ( ( n = TT_LookUp_Table( face, TTAG_cvt ) ) < 0 )
    {
      PTRACE2(( "is missing!\n" ));

      face->cvtSize = 0;
      face->cvt     = NULL;
      return TT_Err_Ok;
    }

    face->cvtSize = face->dirTables[n].Length / 2;

    if ( ALLOC_ARRAY( face->cvt,
                      face->cvtSize,
                      Short ) )
      return error;

    if ( FILE_Seek( face->dirTables[n].Offset ) ||
         ACCESS_Frame( face->cvtSize * 2L ) )
      return error;

    limit = face->cvtSize;

    for ( n = 0; n < limit; n++ )
      face->cvt[n] = GET_Short();

    FORGET_Frame();

    PTRACE2(( "loaded\n" ));

    return TT_Err_Ok;
  }


/*******************************************************************
 *
 *  Function    :  Load_TrueType_CMap
 *
 *  Description :  Loads the cmap directory in memory.
 *                 The cmaps themselves are loaded in ttcmap.c .
 *