Home | History | Annotate | Download | only in sfnt
      1 /***************************************************************************/
      2 /*                                                                         */
      3 /*  ttload.c                                                               */
      4 /*                                                                         */
      5 /*    Load the basic TrueType tables, i.e., tables that can be either in   */
      6 /*    TTF or OTF fonts (body).                                             */
      7 /*                                                                         */
      8 /*  Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,   */
      9 /*            2010 by                                                      */
     10 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
     11 /*                                                                         */
     12 /*  This file is part of the FreeType project, and may only be used,       */
     13 /*  modified, and distributed under the terms of the FreeType project      */
     14 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
     15 /*  this file you indicate that you have read the license and              */
     16 /*  understand and accept it fully.                                        */
     17 /*                                                                         */
     18 /***************************************************************************/
     19 
     20 
     21 #include <ft2build.h>
     22 #include FT_INTERNAL_DEBUG_H
     23 #include FT_INTERNAL_STREAM_H
     24 #include FT_TRUETYPE_TAGS_H
     25 #include "ttload.h"
     26 
     27 #include "sferrors.h"
     28 
     29 
     30   /*************************************************************************/
     31   /*                                                                       */
     32   /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
     33   /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
     34   /* messages during execution.                                            */
     35   /*                                                                       */
     36 #undef  FT_COMPONENT
     37 #define FT_COMPONENT  trace_ttload
     38 
     39 
     40   /*************************************************************************/
     41   /*                                                                       */
     42   /* <Function>                                                            */
     43   /*    tt_face_lookup_table                                               */
     44   /*                                                                       */
     45   /* <Description>                                                         */
     46   /*    Looks for a TrueType table by name.                                */
     47   /*                                                                       */
     48   /* <Input>                                                               */
     49   /*    face :: A face object handle.                                      */
     50   /*                                                                       */
     51   /*    tag  :: The searched tag.                                          */
     52   /*                                                                       */
     53   /* <Return>                                                              */
     54   /*    A pointer to the table directory entry.  0 if not found.           */
     55   /*                                                                       */
     56   FT_LOCAL_DEF( TT_Table  )
     57   tt_face_lookup_table( TT_Face   face,
     58                         FT_ULong  tag  )
     59   {
     60     TT_Table  entry;
     61     TT_Table  limit;
     62 #ifdef FT_DEBUG_LEVEL_TRACE
     63     FT_Bool   zero_length = FALSE;
     64 #endif
     65 
     66 
     67     FT_TRACE4(( "tt_face_lookup_table: %08p, `%c%c%c%c' -- ",
     68                 face,
     69                 (FT_Char)( tag >> 24 ),
     70                 (FT_Char)( tag >> 16 ),
     71                 (FT_Char)( tag >> 8  ),
     72                 (FT_Char)( tag       ) ));
     73 
     74     entry = face->dir_tables;
     75     limit = entry + face->num_tables;
     76 
     77     for ( ; entry < limit; entry++ )
     78     {
     79       /* For compatibility with Windows, we consider    */
     80       /* zero-length tables the same as missing tables. */
     81       if ( entry->Tag == tag )
     82       {
     83         if ( entry->Length != 0 )
     84         {
     85           FT_TRACE4(( "found table.\n" ));
     86           return entry;
     87         }
     88 #ifdef FT_DEBUG_LEVEL_TRACE
     89         zero_length = TRUE;
     90 #endif
     91       }
     92     }
     93 
     94 #ifdef FT_DEBUG_LEVEL_TRACE
     95     if ( zero_length )
     96       FT_TRACE4(( "ignoring empty table\n" ));
     97     else
     98       FT_TRACE4(( "could not find table\n" ));
     99 #endif
    100 
    101     return NULL;
    102   }
    103 
    104 
    105   /*************************************************************************/
    106   /*                                                                       */
    107   /* <Function>                                                            */
    108   /*    tt_face_goto_table                                                 */
    109   /*                                                                       */
    110   /* <Description>                                                         */
    111   /*    Looks for a TrueType table by name, then seek a stream to it.      */
    112   /*                                                                       */
    113   /* <Input>                                                               */
    114   /*    face   :: A face object handle.                                    */
    115   /*                                                                       */
    116   /*    tag    :: The searched tag.                                        */
    117   /*                                                                       */
    118   /*    stream :: The stream to seek when the table is found.              */
    119   /*                                                                       */
    120   /* <Output>                                                              */
    121   /*    length :: The length of the table if found, undefined otherwise.   */
    122   /*                                                                       */
    123   /* <Return>                                                              */
    124   /*    FreeType error code.  0 means success.                             */
    125   /*                                                                       */
    126   FT_LOCAL_DEF( FT_Error )
    127   tt_face_goto_table( TT_Face    face,
    128                       FT_ULong   tag,
    129                       FT_Stream  stream,
    130                       FT_ULong*  length )
    131   {
    132     TT_Table  table;
    133     FT_Error  error;
    134 
    135 
    136     table = tt_face_lookup_table( face, tag );
    137     if ( table )
    138     {
    139       if ( length )
    140         *length = table->Length;
    141 
    142       if ( FT_STREAM_SEEK( table->Offset ) )
    143         goto Exit;
    144     }
    145     else
    146       error = SFNT_Err_Table_Missing;
    147 
    148   Exit:
    149     return error;
    150   }
    151 
    152 
    153   /* Here, we                                                         */
    154   /*                                                                  */
    155   /* - check that `num_tables' is valid (and adjust it if necessary)  */
    156   /*                                                                  */
    157   /* - look for a `head' table, check its size, and parse it to check */
    158   /*   whether its `magic' field is correctly set                     */
    159   /*                                                                  */
    160   /* - errors (except errors returned by stream handling)             */
    161   /*                                                                  */
    162   /*     SFNT_Err_Unknown_File_Format:                                */
    163   /*       no table is defined in directory, it is not sfnt-wrapped   */
    164   /*       data                                                       */
    165   /*     SFNT_Err_Table_Missing:                                      */
    166   /*       table directory is valid, but essential tables             */
    167   /*       (head/bhed/SING) are missing                               */
    168   /*                                                                  */
    169   static FT_Error
    170   check_table_dir( SFNT_Header  sfnt,
    171                    FT_Stream    stream )
    172   {
    173     FT_Error   error;
    174     FT_UShort  nn, valid_entries = 0;
    175     FT_UInt    has_head = 0, has_sing = 0, has_meta = 0;
    176     FT_ULong   offset = sfnt->offset + 12;
    177 
    178     static const FT_Frame_Field  table_dir_entry_fields[] =
    179     {
    180 #undef  FT_STRUCTURE
    181 #define FT_STRUCTURE  TT_TableRec
    182 
    183       FT_FRAME_START( 16 ),
    184         FT_FRAME_ULONG( Tag ),
    185         FT_FRAME_ULONG( CheckSum ),
    186         FT_FRAME_ULONG( Offset ),
    187         FT_FRAME_ULONG( Length ),
    188       FT_FRAME_END
    189     };
    190 
    191 
    192     if ( FT_STREAM_SEEK( offset ) )
    193       goto Exit;
    194 
    195     for ( nn = 0; nn < sfnt->num_tables; nn++ )
    196     {
    197       TT_TableRec  table;
    198 
    199 
    200       if ( FT_STREAM_READ_FIELDS( table_dir_entry_fields, &table ) )
    201       {
    202         nn--;
    203         FT_TRACE2(( "check_table_dir:"
    204                     " can read only %d table%s in font (instead of %d)\n",
    205                     nn, nn == 1 ? "" : "s", sfnt->num_tables ));
    206         sfnt->num_tables = nn;
    207         break;
    208       }
    209 
    210       /* we ignore invalid tables */
    211       if ( table.Offset + table.Length > stream->size )
    212       {
    213         FT_TRACE2(( "check_table_dir: table entry %d invalid\n", nn ));
    214         continue;
    215       }
    216       else
    217         valid_entries++;
    218 
    219       if ( table.Tag == TTAG_head || table.Tag == TTAG_bhed )
    220       {
    221         FT_UInt32  magic;
    222 
    223 
    224 #ifndef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
    225         if ( table.Tag == TTAG_head )
    226 #endif
    227           has_head = 1;
    228 
    229         /*
    230          * The table length should be 0x36, but certain font tools make it
    231          * 0x38, so we will just check that it is greater.
    232          *
    233          * Note that according to the specification, the table must be
    234          * padded to 32-bit lengths, but this doesn't apply to the value of
    235          * its `Length' field!
    236          *
    237          */
    238         if ( table.Length < 0x36 )
    239         {
    240           FT_TRACE2(( "check_table_dir: `head' table too small\n" ));
    241           error = SFNT_Err_Table_Missing;
    242           goto Exit;
    243         }
    244 
    245         if ( FT_STREAM_SEEK( table.Offset + 12 ) ||
    246              FT_READ_ULONG( magic )              )
    247           goto Exit;
    248 
    249         if ( magic != 0x5F0F3CF5UL )
    250         {
    251           FT_TRACE2(( "check_table_dir:"
    252                       " no magic number found in `head' table\n"));
    253           error = SFNT_Err_Table_Missing;
    254           goto Exit;
    255         }
    256 
    257         if ( FT_STREAM_SEEK( offset + ( nn + 1 ) * 16 ) )
    258           goto Exit;
    259       }
    260       else if ( table.Tag == TTAG_SING )
    261         has_sing = 1;
    262       else if ( table.Tag == TTAG_META )
    263         has_meta = 1;
    264     }
    265 
    266     sfnt->num_tables = valid_entries;
    267 
    268     if ( sfnt->num_tables == 0 )
    269     {
    270       FT_TRACE2(( "check_table_dir: no tables found\n" ));
    271       error = SFNT_Err_Unknown_File_Format;
    272       goto Exit;
    273     }
    274 
    275     /* if `sing' and `meta' tables are present, there is no `head' table */
    276     if ( has_head || ( has_sing && has_meta ) )
    277     {
    278       error = SFNT_Err_Ok;
    279       goto Exit;
    280     }
    281     else
    282     {
    283       FT_TRACE2(( "check_table_dir:" ));
    284 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
    285       FT_TRACE2(( " neither `head', `bhed', nor `sing' table found\n" ));
    286 #else
    287       FT_TRACE2(( " neither `head' nor `sing' table found\n" ));
    288 #endif
    289       error = SFNT_Err_Table_Missing;
    290     }
    291 
    292   Exit:
    293     return error;
    294   }
    295 
    296 
    297   /*************************************************************************/
    298   /*                                                                       */
    299   /* <Function>                                                            */
    300   /*    tt_face_load_font_dir                                              */
    301   /*                                                                       */
    302   /* <Description>                                                         */
    303   /*    Loads the header of a SFNT font file.                              */
    304   /*                                                                       */
    305   /* <Input>                                                               */
    306   /*    face       :: A handle to the target face object.                  */
    307   /*                                                                       */
    308   /*    stream     :: The input stream.                                    */
    309   /*                                                                       */
    310   /* <Output>                                                              */
    311   /*    sfnt       :: The SFNT header.                                     */
    312   /*                                                                       */
    313   /* <Return>                                                              */
    314   /*    FreeType error code.  0 means success.                             */
    315   /*                                                                       */
    316   /* <Note>                                                                */
    317   /*    The stream cursor must be at the beginning of the font directory.  */
    318   /*                                                                       */
    319   FT_LOCAL_DEF( FT_Error )
    320   tt_face_load_font_dir( TT_Face    face,
    321                          FT_Stream  stream )
    322   {
    323     SFNT_HeaderRec  sfnt;
    324     FT_Error        error;
    325     FT_Memory       memory = stream->memory;
    326     TT_TableRec*    entry;
    327     FT_Int          nn;
    328 
    329     static const FT_Frame_Field  offset_table_fields[] =
    330     {
    331 #undef  FT_STRUCTURE
    332 #define FT_STRUCTURE  SFNT_HeaderRec
    333 
    334       FT_FRAME_START( 8 ),
    335         FT_FRAME_USHORT( num_tables ),
    336         FT_FRAME_USHORT( search_range ),
    337         FT_FRAME_USHORT( entry_selector ),
    338         FT_FRAME_USHORT( range_shift ),
    339       FT_FRAME_END
    340     };
    341 
    342 
    343     FT_TRACE2(( "tt_face_load_font_dir: %08p\n", face ));
    344 
    345     /* read the offset table */
    346 
    347     sfnt.offset = FT_STREAM_POS();
    348 
    349     if ( FT_READ_ULONG( sfnt.format_tag )                    ||
    350          FT_STREAM_READ_FIELDS( offset_table_fields, &sfnt ) )
    351       goto Exit;
    352 
    353     /* many fonts don't have these fields set correctly */
    354 #if 0
    355     if ( sfnt.search_range != 1 << ( sfnt.entry_selector + 4 )        ||
    356          sfnt.search_range + sfnt.range_shift != sfnt.num_tables << 4 )
    357       return SFNT_Err_Unknown_File_Format;
    358 #endif
    359 
    360     /* load the table directory */
    361 
    362     FT_TRACE2(( "-- Number of tables: %10u\n",    sfnt.num_tables ));
    363     FT_TRACE2(( "-- Format version:   0x%08lx\n", sfnt.format_tag ));
    364 
    365     /* check first */
    366     error = check_table_dir( &sfnt, stream );
    367     if ( error )
    368     {
    369       FT_TRACE2(( "tt_face_load_font_dir:"
    370                   " invalid table directory for TrueType\n" ));
    371 
    372       goto Exit;
    373     }
    374 
    375     face->num_tables = sfnt.num_tables;
    376     face->format_tag = sfnt.format_tag;
    377 
    378     if ( FT_QNEW_ARRAY( face->dir_tables, face->num_tables ) )
    379       goto Exit;
    380 
    381     if ( FT_STREAM_SEEK( sfnt.offset + 12 )       ||
    382          FT_FRAME_ENTER( face->num_tables * 16L ) )
    383       goto Exit;
    384 
    385     entry = face->dir_tables;
    386 
    387     FT_TRACE2(( "\n"
    388                 "  tag    offset    length   checksum\n"
    389                 "  ----------------------------------\n" ));
    390 
    391     for ( nn = 0; nn < sfnt.num_tables; nn++ )
    392     {
    393       entry->Tag      = FT_GET_TAG4();
    394       entry->CheckSum = FT_GET_ULONG();
    395       entry->Offset   = FT_GET_LONG();
    396       entry->Length   = FT_GET_LONG();
    397 
    398       /* ignore invalid tables */
    399       if ( entry->Offset + entry->Length > stream->size )
    400         continue;
    401       else
    402       {
    403         FT_TRACE2(( "  %c%c%c%c  %08lx  %08lx  %08lx\n",
    404                     (FT_Char)( entry->Tag >> 24 ),
    405                     (FT_Char)( entry->Tag >> 16 ),
    406                     (FT_Char)( entry->Tag >> 8  ),
    407                     (FT_Char)( entry->Tag       ),
    408                     entry->Offset,
    409                     entry->Length,
    410                     entry->CheckSum ));
    411         entry++;
    412       }
    413     }
    414 
    415     FT_FRAME_EXIT();
    416 
    417     FT_TRACE2(( "table directory loaded\n\n" ));
    418 
    419   Exit:
    420     return error;
    421   }
    422 
    423 
    424   /*************************************************************************/
    425   /*                                                                       */
    426   /* <Function>                                                            */
    427   /*    tt_face_load_any                                                   */
    428   /*                                                                       */
    429   /* <Description>                                                         */
    430   /*    Loads any font table into client memory.                           */
    431   /*                                                                       */
    432   /* <Input>                                                               */
    433   /*    face   :: The face object to look for.                             */
    434   /*                                                                       */
    435   /*    tag    :: The tag of table to load.  Use the value 0 if you want   */
    436   /*              to access the whole font file, else set this parameter   */
    437   /*              to a valid TrueType table tag that you can forge with    */
    438   /*              the MAKE_TT_TAG macro.                                   */
    439   /*                                                                       */
    440   /*    offset :: The starting offset in the table (or the file if         */
    441   /*              tag == 0).                                               */
    442   /*                                                                       */
    443   /*    length :: The address of the decision variable:                    */
    444   /*                                                                       */
    445   /*                If length == NULL:                                     */
    446   /*                  Loads the whole table.  Returns an error if          */
    447   /*                  `offset' == 0!                                       */
    448   /*                                                                       */
    449   /*                If *length == 0:                                       */
    450   /*                  Exits immediately; returning the length of the given */
    451   /*                  table or of the font file, depending on the value of */
    452   /*                  `tag'.                                               */
    453   /*                                                                       */
    454   /*                If *length != 0:                                       */
    455   /*                  Loads the next `length' bytes of table or font,      */
    456   /*                  starting at offset `offset' (in table or font too).  */
    457   /*                                                                       */
    458   /* <Output>                                                              */
    459   /*    buffer :: The address of target buffer.                            */
    460   /*                                                                       */
    461   /* <Return>                                                              */
    462   /*    FreeType error code.  0 means success.                             */
    463   /*                                                                       */
    464   FT_LOCAL_DEF( FT_Error )
    465   tt_face_load_any( TT_Face    face,
    466                     FT_ULong   tag,
    467                     FT_Long    offset,
    468                     FT_Byte*   buffer,
    469                     FT_ULong*  length )
    470   {
    471     FT_Error   error;
    472     FT_Stream  stream;
    473     TT_Table   table;
    474     FT_ULong   size;
    475 
    476 
    477     if ( tag != 0 )
    478     {
    479       /* look for tag in font directory */
    480       table = tt_face_lookup_table( face, tag );
    481       if ( !table )
    482       {
    483         error = SFNT_Err_Table_Missing;
    484         goto Exit;
    485       }
    486 
    487       offset += table->Offset;
    488       size    = table->Length;
    489     }
    490     else
    491       /* tag == 0 -- the user wants to access the font file directly */
    492       size = face->root.stream->size;
    493 
    494     if ( length && *length == 0 )
    495     {
    496       *length = size;
    497 
    498       return SFNT_Err_Ok;
    499     }
    500 
    501     if ( length )
    502       size = *length;
    503 
    504     stream = face->root.stream;
    505     /* the `if' is syntactic sugar for picky compilers */
    506     if ( FT_STREAM_READ_AT( offset, buffer, size ) )
    507       goto Exit;
    508 
    509   Exit:
    510     return error;
    511   }
    512 
    513 
    514   /*************************************************************************/
    515   /*                                                                       */
    516   /* <Function>                                                            */
    517   /*    tt_face_load_generic_header                                        */
    518   /*                                                                       */
    519   /* <Description>                                                         */
    520   /*    Loads the TrueType table `head' or `bhed'.                         */
    521   /*                                                                       */
    522   /* <Input>                                                               */
    523   /*    face   :: A handle to the target face object.                      */
    524   /*                                                                       */
    525   /*    stream :: The input stream.                                        */
    526   /*                                                                       */
    527   /* <Return>                                                              */
    528   /*    FreeType error code.  0 means success.                             */
    529   /*                                                                       */
    530   static FT_Error
    531   tt_face_load_generic_header( TT_Face    face,
    532                                FT_Stream  stream,
    533                                FT_ULong   tag )
    534   {
    535     FT_Error    error;
    536     TT_Header*  header;
    537 
    538     static const FT_Frame_Field  header_fields[] =
    539     {
    540 #undef  FT_STRUCTURE
    541 #define FT_STRUCTURE  TT_Header
    542 
    543       FT_FRAME_START( 54 ),
    544         FT_FRAME_ULONG ( Table_Version ),
    545         FT_FRAME_ULONG ( Font_Revision ),
    546         FT_FRAME_LONG  ( CheckSum_Adjust ),
    547         FT_FRAME_LONG  ( Magic_Number ),
    548         FT_FRAME_USHORT( Flags ),
    549         FT_FRAME_USHORT( Units_Per_EM ),
    550         FT_FRAME_LONG  ( Created[0] ),
    551         FT_FRAME_LONG  ( Created[1] ),
    552         FT_FRAME_LONG  ( Modified[0] ),
    553         FT_FRAME_LONG  ( Modified[1] ),
    554         FT_FRAME_SHORT ( xMin ),
    555         FT_FRAME_SHORT ( yMin ),
    556         FT_FRAME_SHORT ( xMax ),
    557         FT_FRAME_SHORT ( yMax ),
    558         FT_FRAME_USHORT( Mac_Style ),
    559         FT_FRAME_USHORT( Lowest_Rec_PPEM ),
    560         FT_FRAME_SHORT ( Font_Direction ),
    561         FT_FRAME_SHORT ( Index_To_Loc_Format ),
    562         FT_FRAME_SHORT ( Glyph_Data_Format ),
    563       FT_FRAME_END
    564     };
    565 
    566 
    567     error = face->goto_table( face, tag, stream, 0 );
    568     if ( error )
    569       goto Exit;
    570 
    571     header = &face->header;
    572 
    573     if ( FT_STREAM_READ_FIELDS( header_fields, header ) )
    574       goto Exit;
    575 
    576     FT_TRACE3(( "Units per EM: %4u\n", header->Units_Per_EM ));
    577     FT_TRACE3(( "IndexToLoc:   %4d\n", header->Index_To_Loc_Format ));
    578 
    579   Exit:
    580     return error;
    581   }
    582 
    583 
    584   FT_LOCAL_DEF( FT_Error )
    585   tt_face_load_head( TT_Face    face,
    586                      FT_Stream  stream )
    587   {
    588     return tt_face_load_generic_header( face, stream, TTAG_head );
    589   }
    590 
    591 
    592 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
    593 
    594   FT_LOCAL_DEF( FT_Error )
    595   tt_face_load_bhed( TT_Face    face,
    596                      FT_Stream  stream )
    597   {
    598     return tt_face_load_generic_header( face, stream, TTAG_bhed );
    599   }
    600 
    601 #endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
    602 
    603 
    604   /*************************************************************************/
    605   /*                                                                       */
    606   /* <Function>                                                            */
    607   /*    tt_face_load_max_profile                                           */
    608   /*                                                                       */
    609   /* <Description>                                                         */
    610   /*    Loads the maximum profile into a face object.                      */
    611   /*                                                                       */
    612   /* <Input>                                                               */
    613   /*    face   :: A handle to the target face object.                      */
    614   /*                                                                       */
    615   /*    stream :: The input stream.                                        */
    616   /*                                                                       */
    617   /* <Return>                                                              */
    618   /*    FreeType error code.  0 means success.                             */
    619   /*                                                                       */
    620   FT_LOCAL_DEF( FT_Error )
    621   tt_face_load_maxp( TT_Face    face,
    622                      FT_Stream  stream )
    623   {
    624     FT_Error        error;
    625     TT_MaxProfile*  maxProfile = &face->max_profile;
    626 
    627     const FT_Frame_Field  maxp_fields[] =
    628     {
    629 #undef  FT_STRUCTURE
    630 #define FT_STRUCTURE  TT_MaxProfile
    631 
    632       FT_FRAME_START( 6 ),
    633         FT_FRAME_LONG  ( version ),
    634         FT_FRAME_USHORT( numGlyphs ),
    635       FT_FRAME_END
    636     };
    637 
    638     const FT_Frame_Field  maxp_fields_extra[] =
    639     {
    640       FT_FRAME_START( 26 ),
    641         FT_FRAME_USHORT( maxPoints ),
    642         FT_FRAME_USHORT( maxContours ),
    643         FT_FRAME_USHORT( maxCompositePoints ),
    644         FT_FRAME_USHORT( maxCompositeContours ),
    645         FT_FRAME_USHORT( maxZones ),
    646         FT_FRAME_USHORT( maxTwilightPoints ),
    647         FT_FRAME_USHORT( maxStorage ),
    648         FT_FRAME_USHORT( maxFunctionDefs ),
    649         FT_FRAME_USHORT( maxInstructionDefs ),
    650         FT_FRAME_USHORT( maxStackElements ),
    651         FT_FRAME_USHORT( maxSizeOfInstructions ),
    652         FT_FRAME_USHORT( maxComponentElements ),
    653         FT_FRAME_USHORT( maxComponentDepth ),
    654       FT_FRAME_END
    655     };
    656 
    657 
    658     error = face->goto_table( face, TTAG_maxp, stream, 0 );
    659     if ( error )
    660       goto Exit;
    661 
    662     if ( FT_STREAM_READ_FIELDS( maxp_fields, maxProfile ) )
    663       goto Exit;
    664 
    665     maxProfile->maxPoints             = 0;
    666     maxProfile->maxContours           = 0;
    667     maxProfile->maxCompositePoints    = 0;
    668     maxProfile->maxCompositeContours  = 0;
    669     maxProfile->maxZones              = 0;
    670     maxProfile->maxTwilightPoints     = 0;
    671     maxProfile->maxStorage            = 0;
    672     maxProfile->maxFunctionDefs       = 0;
    673     maxProfile->maxInstructionDefs    = 0;
    674     maxProfile->maxStackElements      = 0;
    675     maxProfile->maxSizeOfInstructions = 0;
    676     maxProfile->maxComponentElements  = 0;
    677     maxProfile->maxComponentDepth     = 0;
    678 
    679     if ( maxProfile->version >= 0x10000L )
    680     {
    681       if ( FT_STREAM_READ_FIELDS( maxp_fields_extra, maxProfile ) )
    682         goto Exit;
    683 
    684       /* XXX: an adjustment that is necessary to load certain */
    685       /*      broken fonts like `Keystrokes MT' :-(           */
    686       /*                                                      */
    687       /*   We allocate 64 function entries by default when    */
    688       /*   the maxFunctionDefs value is smaller.              */
    689 
    690       if ( maxProfile->maxFunctionDefs < 64 )
    691         maxProfile->maxFunctionDefs = 64;
    692 
    693       /* we add 4 phantom points later */
    694       if ( maxProfile->maxTwilightPoints > ( 0xFFFFU - 4 ) )
    695       {
    696         FT_TRACE0(( "tt_face_load_maxp:"
    697                     " too much twilight points in `maxp' table;\n"
    698                     "                  "
    699                     " some glyphs might be rendered incorrectly\n" ));
    700 
    701         maxProfile->maxTwilightPoints = 0xFFFFU - 4;
    702       }
    703 
    704       /* we arbitrarily limit recursion to avoid stack exhaustion */
    705       if ( maxProfile->maxComponentDepth > 100 )
    706       {
    707         FT_TRACE0(( "tt_face_load_maxp:"
    708                     " abnormally large component depth (%d) set to 100\n",
    709                     maxProfile->maxComponentDepth ));
    710         maxProfile->maxComponentDepth = 100;
    711       }
    712     }
    713 
    714     FT_TRACE3(( "numGlyphs: %u\n", maxProfile->numGlyphs ));
    715 
    716   Exit:
    717     return error;
    718   }
    719 
    720 
    721   /*************************************************************************/
    722   /*                                                                       */
    723   /* <Function>                                                            */
    724   /*    tt_face_load_names                                                 */
    725   /*                                                                       */
    726   /* <Description>                                                         */
    727   /*    Loads the name records.                                            */
    728   /*                                                                       */
    729   /* <Input>                                                               */
    730   /*    face   :: A handle to the target face object.                      */
    731   /*                                                                       */
    732   /*    stream :: The input stream.                                        */
    733   /*                                                                       */
    734   /* <Return>                                                              */
    735   /*    FreeType error code.  0 means success.                             */
    736   /*                                                                       */
    737   FT_LOCAL_DEF( FT_Error )
    738   tt_face_load_name( TT_Face    face,
    739                      FT_Stream  stream )
    740   {
    741     FT_Error      error;
    742     FT_Memory     memory = stream->memory;
    743     FT_ULong      table_pos, table_len;
    744     FT_ULong      storage_start, storage_limit;
    745     FT_UInt       count;
    746     TT_NameTable  table;
    747 
    748     static const FT_Frame_Field  name_table_fields[] =
    749     {
    750 #undef  FT_STRUCTURE
    751 #define FT_STRUCTURE  TT_NameTableRec
    752 
    753       FT_FRAME_START( 6 ),
    754         FT_FRAME_USHORT( format ),
    755         FT_FRAME_USHORT( numNameRecords ),
    756         FT_FRAME_USHORT( storageOffset ),
    757       FT_FRAME_END
    758     };
    759 
    760     static const FT_Frame_Field  name_record_fields[] =
    761     {
    762 #undef  FT_STRUCTURE
    763 #define FT_STRUCTURE  TT_NameEntryRec
    764 
    765       /* no FT_FRAME_START */
    766         FT_FRAME_USHORT( platformID ),
    767         FT_FRAME_USHORT( encodingID ),
    768         FT_FRAME_USHORT( languageID ),
    769         FT_FRAME_USHORT( nameID ),
    770         FT_FRAME_USHORT( stringLength ),
    771         FT_FRAME_USHORT( stringOffset ),
    772       FT_FRAME_END
    773     };
    774 
    775 
    776     table         = &face->name_table;
    777     table->stream = stream;
    778 
    779     error = face->goto_table( face, TTAG_name, stream, &table_len );
    780     if ( error )
    781       goto Exit;
    782 
    783     table_pos = FT_STREAM_POS();
    784 
    785 
    786     if ( FT_STREAM_READ_FIELDS( name_table_fields, table ) )
    787       goto Exit;
    788 
    789     /* Some popular Asian fonts have an invalid `storageOffset' value   */
    790     /* (it should be at least "6 + 12*num_names").  However, the string */
    791     /* offsets, computed as "storageOffset + entry->stringOffset", are  */
    792     /* valid pointers within the name table...                          */
    793     /*                                                                  */
    794     /* We thus can't check `storageOffset' right now.                   */
    795     /*                                                                  */
    796     storage_start = table_pos + 6 + 12*table->numNameRecords;
    797     storage_limit = table_pos + table_len;
    798 
    799     if ( storage_start > storage_limit )
    800     {
    801       FT_ERROR(( "tt_face_load_name: invalid `name' table\n" ));
    802       error = SFNT_Err_Name_Table_Missing;
    803       goto Exit;
    804     }
    805 
    806     /* Allocate the array of name records. */
    807     count                 = table->numNameRecords;
    808     table->numNameRecords = 0;
    809 
    810     if ( FT_NEW_ARRAY( table->names, count ) ||
    811          FT_FRAME_ENTER( count * 12 )        )
    812       goto Exit;
    813 
    814     /* Load the name records and determine how much storage is needed */
    815     /* to hold the strings themselves.                                */
    816     {
    817       TT_NameEntryRec*  entry = table->names;
    818 
    819 
    820       for ( ; count > 0; count-- )
    821       {
    822         if ( FT_STREAM_READ_FIELDS( name_record_fields, entry ) )
    823           continue;
    824 
    825         /* check that the name is not empty */
    826         if ( entry->stringLength == 0 )
    827           continue;
    828 
    829         /* check that the name string is within the table */
    830         entry->stringOffset += table_pos + table->storageOffset;
    831         if ( entry->stringOffset                       < storage_start ||
    832              entry->stringOffset + entry->stringLength > storage_limit )
    833         {
    834           /* invalid entry - ignore it */
    835           entry->stringOffset = 0;
    836           entry->stringLength = 0;
    837           continue;
    838         }
    839 
    840         entry++;
    841       }
    842 
    843       table->numNameRecords = (FT_UInt)( entry - table->names );
    844     }
    845 
    846     FT_FRAME_EXIT();
    847 
    848     /* everything went well, update face->num_names */
    849     face->num_names = (FT_UShort) table->numNameRecords;
    850 
    851   Exit:
    852     return error;
    853   }
    854 
    855 
    856   /*************************************************************************/
    857   /*                                                                       */
    858   /* <Function>                                                            */
    859   /*    tt_face_free_names                                                 */
    860   /*                                                                       */
    861   /* <Description>                                                         */
    862   /*    Frees the name records.                                            */
    863   /*                                                                       */
    864   /* <Input>                                                               */
    865   /*    face :: A handle to the target face object.                        */
    866   /*                                                                       */
    867   FT_LOCAL_DEF( void )
    868   tt_face_free_name( TT_Face  face )
    869   {
    870     FT_Memory     memory = face->root.driver->root.memory;
    871     TT_NameTable  table  = &face->name_table;
    872     TT_NameEntry  entry  = table->names;
    873     FT_UInt       count  = table->numNameRecords;
    874 
    875 
    876     if ( table->names )
    877     {
    878       for ( ; count > 0; count--, entry++ )
    879       {
    880         FT_FREE( entry->string );
    881         entry->stringLength = 0;
    882       }
    883 
    884       /* free strings table */
    885       FT_FREE( table->names );
    886     }
    887 
    888     table->numNameRecords = 0;
    889     table->format         = 0;
    890     table->storageOffset  = 0;
    891   }
    892 
    893 
    894   /*************************************************************************/
    895   /*                                                                       */
    896   /* <Function>                                                            */
    897   /*    tt_face_load_cmap                                                  */
    898   /*                                                                       */
    899   /* <Description>                                                         */
    900   /*    Loads the cmap directory in a face object.  The cmaps themselves   */
    901   /*    are loaded on demand in the `ttcmap.c' module.                     */
    902   /*                                                                       */
    903   /* <Input>                                                               */
    904   /*    face   :: A handle to the target face object.                      */
    905   /*                                                                       */
    906   /*    stream :: A handle to the input stream.                            */
    907   /*                                                                       */
    908   /* <Return>                                                              */
    909   /*    FreeType error code.  0 means success.                             */
    910   /*                                                                       */
    911 
    912   FT_LOCAL_DEF( FT_Error )
    913   tt_face_load_cmap( TT_Face    face,
    914                      FT_Stream  stream )
    915   {
    916     FT_Error  error;
    917 
    918 
    919     error = face->goto_table( face, TTAG_cmap, stream, &face->cmap_size );
    920     if ( error )
    921       goto Exit;
    922 
    923     if ( FT_FRAME_EXTRACT( face->cmap_size, face->cmap_table ) )
    924       face->cmap_size = 0;
    925 
    926   Exit:
    927     return error;
    928   }
    929 
    930 
    931 
    932   /*************************************************************************/
    933   /*                                                                       */
    934   /* <Function>                                                            */
    935   /*    tt_face_load_os2                                                   */
    936   /*                                                                       */
    937   /* <Description>                                                         */
    938   /*    Loads the OS2 table.                                               */
    939   /*                                                                       */
    940   /* <Input>                                                               */
    941   /*    face   :: A handle to the target face object.                      */
    942   /*                                                                       */
    943   /*    stream :: A handle to the input stream.                            */
    944   /*                                                                       */
    945   /* <Return>                                                              */
    946   /*    FreeType error code.  0 means success.                             */
    947   /*                                                                       */
    948   FT_LOCAL_DEF( FT_Error )
    949   tt_face_load_os2( TT_Face    face,
    950                     FT_Stream  stream )
    951   {
    952     FT_Error  error;
    953     TT_OS2*   os2;
    954 
    955     const FT_Frame_Field  os2_fields[] =
    956     {
    957 #undef  FT_STRUCTURE
    958 #define FT_STRUCTURE  TT_OS2
    959 
    960       FT_FRAME_START( 78 ),
    961         FT_FRAME_USHORT( version ),
    962         FT_FRAME_SHORT ( xAvgCharWidth ),
    963         FT_FRAME_USHORT( usWeightClass ),
    964         FT_FRAME_USHORT( usWidthClass ),
    965         FT_FRAME_SHORT ( fsType ),
    966         FT_FRAME_SHORT ( ySubscriptXSize ),
    967         FT_FRAME_SHORT ( ySubscriptYSize ),
    968         FT_FRAME_SHORT ( ySubscriptXOffset ),
    969         FT_FRAME_SHORT ( ySubscriptYOffset ),
    970         FT_FRAME_SHORT ( ySuperscriptXSize ),
    971         FT_FRAME_SHORT ( ySuperscriptYSize ),
    972         FT_FRAME_SHORT ( ySuperscriptXOffset ),
    973         FT_FRAME_SHORT ( ySuperscriptYOffset ),
    974         FT_FRAME_SHORT ( yStrikeoutSize ),
    975         FT_FRAME_SHORT ( yStrikeoutPosition ),
    976         FT_FRAME_SHORT ( sFamilyClass ),
    977         FT_FRAME_BYTE  ( panose[0] ),
    978         FT_FRAME_BYTE  ( panose[1] ),
    979         FT_FRAME_BYTE  ( panose[2] ),
    980         FT_FRAME_BYTE  ( panose[3] ),
    981         FT_FRAME_BYTE  ( panose[4] ),
    982         FT_FRAME_BYTE  ( panose[5] ),
    983         FT_FRAME_BYTE  ( panose[6] ),
    984         FT_FRAME_BYTE  ( panose[7] ),
    985         FT_FRAME_BYTE  ( panose[8] ),
    986         FT_FRAME_BYTE  ( panose[9] ),
    987         FT_FRAME_ULONG ( ulUnicodeRange1 ),
    988         FT_FRAME_ULONG ( ulUnicodeRange2 ),
    989         FT_FRAME_ULONG ( ulUnicodeRange3 ),
    990         FT_FRAME_ULONG ( ulUnicodeRange4 ),
    991         FT_FRAME_BYTE  ( achVendID[0] ),
    992         FT_FRAME_BYTE  ( achVendID[1] ),
    993         FT_FRAME_BYTE  ( achVendID[2] ),
    994         FT_FRAME_BYTE  ( achVendID[3] ),
    995 
    996         FT_FRAME_USHORT( fsSelection ),
    997         FT_FRAME_USHORT( usFirstCharIndex ),
    998         FT_FRAME_USHORT( usLastCharIndex ),
    999         FT_FRAME_SHORT ( sTypoAscender ),
   1000         FT_FRAME_SHORT ( sTypoDescender ),
   1001         FT_FRAME_SHORT ( sTypoLineGap ),
   1002         FT_FRAME_USHORT( usWinAscent ),
   1003         FT_FRAME_USHORT( usWinDescent ),
   1004       FT_FRAME_END
   1005     };
   1006 
   1007     const FT_Frame_Field  os2_fields_extra[] =
   1008     {
   1009       FT_FRAME_START( 8 ),
   1010         FT_FRAME_ULONG( ulCodePageRange1 ),
   1011         FT_FRAME_ULONG( ulCodePageRange2 ),
   1012       FT_FRAME_END
   1013     };
   1014 
   1015     const FT_Frame_Field  os2_fields_extra2[] =
   1016     {
   1017       FT_FRAME_START( 10 ),
   1018         FT_FRAME_SHORT ( sxHeight ),
   1019         FT_FRAME_SHORT ( sCapHeight ),
   1020         FT_FRAME_USHORT( usDefaultChar ),
   1021         FT_FRAME_USHORT( usBreakChar ),
   1022         FT_FRAME_USHORT( usMaxContext ),
   1023       FT_FRAME_END
   1024     };
   1025 
   1026 
   1027     /* We now support old Mac fonts where the OS/2 table doesn't  */
   1028     /* exist.  Simply put, we set the `version' field to 0xFFFF   */
   1029     /* and test this value each time we need to access the table. */
   1030     error = face->goto_table( face, TTAG_OS2, stream, 0 );
   1031     if ( error )
   1032       goto Exit;
   1033 
   1034     os2 = &face->os2;
   1035 
   1036     if ( FT_STREAM_READ_FIELDS( os2_fields, os2 ) )
   1037       goto Exit;
   1038 
   1039     os2->ulCodePageRange1 = 0;
   1040     os2->ulCodePageRange2 = 0;
   1041     os2->sxHeight         = 0;
   1042     os2->sCapHeight       = 0;
   1043     os2->usDefaultChar    = 0;
   1044     os2->usBreakChar      = 0;
   1045     os2->usMaxContext     = 0;
   1046 
   1047     if ( os2->version >= 0x0001 )
   1048     {
   1049       /* only version 1 tables */
   1050       if ( FT_STREAM_READ_FIELDS( os2_fields_extra, os2 ) )
   1051         goto Exit;
   1052 
   1053       if ( os2->version >= 0x0002 )
   1054       {
   1055         /* only version 2 tables */
   1056         if ( FT_STREAM_READ_FIELDS( os2_fields_extra2, os2 ) )
   1057           goto Exit;
   1058       }
   1059     }
   1060 
   1061     FT_TRACE3(( "sTypoAscender:  %4d\n",   os2->sTypoAscender ));
   1062     FT_TRACE3(( "sTypoDescender: %4d\n",   os2->sTypoDescender ));
   1063     FT_TRACE3(( "usWinAscent:    %4u\n",   os2->usWinAscent ));
   1064     FT_TRACE3(( "usWinDescent:   %4u\n",   os2->usWinDescent ));
   1065     FT_TRACE3(( "fsSelection:    0x%2x\n", os2->fsSelection ));
   1066 
   1067   Exit:
   1068     return error;
   1069   }
   1070 
   1071 
   1072   /*************************************************************************/
   1073   /*                                                                       */
   1074   /* <Function>                                                            */
   1075   /*    tt_face_load_postscript                                            */
   1076   /*                                                                       */
   1077   /* <Description>                                                         */
   1078   /*    Loads the Postscript table.                                        */
   1079   /*                                                                       */
   1080   /* <Input>                                                               */
   1081   /*    face   :: A handle to the target face object.                      */
   1082   /*                                                                       */
   1083   /*    stream :: A handle to the input stream.                            */
   1084   /*                                                                       */
   1085   /* <Return>                                                              */
   1086   /*    FreeType error code.  0 means success.                             */
   1087   /*                                                                       */
   1088   FT_LOCAL_DEF( FT_Error )
   1089   tt_face_load_post( TT_Face    face,
   1090                      FT_Stream  stream )
   1091   {
   1092     FT_Error        error;
   1093     TT_Postscript*  post = &face->postscript;
   1094 
   1095     static const FT_Frame_Field  post_fields[] =
   1096     {
   1097 #undef  FT_STRUCTURE
   1098 #define FT_STRUCTURE  TT_Postscript
   1099 
   1100       FT_FRAME_START( 32 ),
   1101         FT_FRAME_ULONG( FormatType ),
   1102         FT_FRAME_ULONG( italicAngle ),
   1103         FT_FRAME_SHORT( underlinePosition ),
   1104         FT_FRAME_SHORT( underlineThickness ),
   1105         FT_FRAME_ULONG( isFixedPitch ),
   1106         FT_FRAME_ULONG( minMemType42 ),
   1107         FT_FRAME_ULONG( maxMemType42 ),
   1108         FT_FRAME_ULONG( minMemType1 ),
   1109         FT_FRAME_ULONG( maxMemType1 ),
   1110       FT_FRAME_END
   1111     };
   1112 
   1113 
   1114     error = face->goto_table( face, TTAG_post, stream, 0 );
   1115     if ( error )
   1116       return error;
   1117 
   1118     if ( FT_STREAM_READ_FIELDS( post_fields, post ) )
   1119       return error;
   1120 
   1121     /* we don't load the glyph names, we do that in another */
   1122     /* module (ttpost).                                     */
   1123 
   1124     FT_TRACE3(( "FormatType:   0x%x\n", post->FormatType ));
   1125     FT_TRACE3(( "isFixedPitch:   %s\n", post->isFixedPitch
   1126                                         ? "  yes" : "   no" ));
   1127 
   1128     return SFNT_Err_Ok;
   1129   }
   1130 
   1131 
   1132   /*************************************************************************/
   1133   /*                                                                       */
   1134   /* <Function>                                                            */
   1135   /*    tt_face_load_pclt                                                  */
   1136   /*                                                                       */
   1137   /* <Description>                                                         */
   1138   /*    Loads the PCL 5 Table.                                             */
   1139   /*                                                                       */
   1140   /* <Input>                                                               */
   1141   /*    face   :: A handle to the target face object.                      */
   1142   /*                                                                       */
   1143   /*    stream :: A handle to the input stream.                            */
   1144   /*                                                                       */
   1145   /* <Return>                                                              */
   1146   /*    FreeType error code.  0 means success.                             */
   1147   /*                                                                       */
   1148   FT_LOCAL_DEF( FT_Error )
   1149   tt_face_load_pclt( TT_Face    face,
   1150                      FT_Stream  stream )
   1151   {
   1152     static const FT_Frame_Field  pclt_fields[] =
   1153     {
   1154 #undef  FT_STRUCTURE
   1155 #define FT_STRUCTURE  TT_PCLT
   1156 
   1157       FT_FRAME_START( 54 ),
   1158         FT_FRAME_ULONG ( Version ),
   1159         FT_FRAME_ULONG ( FontNumber ),
   1160         FT_FRAME_USHORT( Pitch ),
   1161         FT_FRAME_USHORT( xHeight ),
   1162         FT_FRAME_USHORT( Style ),
   1163         FT_FRAME_USHORT( TypeFamily ),
   1164         FT_FRAME_USHORT( CapHeight ),
   1165         FT_FRAME_BYTES ( TypeFace, 16 ),
   1166         FT_FRAME_BYTES ( CharacterComplement, 8 ),
   1167         FT_FRAME_BYTES ( FileName, 6 ),
   1168         FT_FRAME_CHAR  ( StrokeWeight ),
   1169         FT_FRAME_CHAR  ( WidthType ),
   1170         FT_FRAME_BYTE  ( SerifStyle ),
   1171         FT_FRAME_BYTE  ( Reserved ),
   1172       FT_FRAME_END
   1173     };
   1174 
   1175     FT_Error  error;
   1176     TT_PCLT*  pclt = &face->pclt;
   1177 
   1178 
   1179     /* optional table */
   1180     error = face->goto_table( face, TTAG_PCLT, stream, 0 );
   1181     if ( error )
   1182       goto Exit;
   1183 
   1184     if ( FT_STREAM_READ_FIELDS( pclt_fields, pclt ) )
   1185       goto Exit;
   1186 
   1187   Exit:
   1188     return error;
   1189   }
   1190 
   1191 
   1192   /*************************************************************************/
   1193   /*                                                                       */
   1194   /* <Function>                                                            */
   1195   /*    tt_face_load_gasp                                                  */
   1196   /*                                                                       */
   1197   /* <Description>                                                         */
   1198   /*    Loads the `gasp' table into a face object.                         */
   1199   /*                                                                       */
   1200   /* <Input>                                                               */
   1201   /*    face   :: A handle to the target face object.                      */
   1202   /*                                                                       */
   1203   /*    stream :: The input stream.                                        */
   1204   /*                                                                       */
   1205   /* <Return>                                                              */
   1206   /*    FreeType error code.  0 means success.                             */
   1207   /*                                                                       */
   1208   FT_LOCAL_DEF( FT_Error )
   1209   tt_face_load_gasp( TT_Face    face,
   1210                      FT_Stream  stream )
   1211   {
   1212     FT_Error   error;
   1213     FT_Memory  memory = stream->memory;
   1214 
   1215     FT_UInt        j,num_ranges;
   1216     TT_GaspRange   gaspranges = NULL;
   1217 
   1218 
   1219     /* the gasp table is optional */
   1220     error = face->goto_table( face, TTAG_gasp, stream, 0 );
   1221     if ( error )
   1222       goto Exit;
   1223 
   1224     if ( FT_FRAME_ENTER( 4L ) )
   1225       goto Exit;
   1226 
   1227     face->gasp.version   = FT_GET_USHORT();
   1228     face->gasp.numRanges = FT_GET_USHORT();
   1229 
   1230     FT_FRAME_EXIT();
   1231 
   1232     /* only support versions 0 and 1 of the table */
   1233     if ( face->gasp.version >= 2 )
   1234     {
   1235       face->gasp.numRanges = 0;
   1236       error = SFNT_Err_Invalid_Table;
   1237       goto Exit;
   1238     }
   1239 
   1240     num_ranges = face->gasp.numRanges;
   1241     FT_TRACE3(( "numRanges: %u\n", num_ranges ));
   1242 
   1243     if ( FT_QNEW_ARRAY( gaspranges, num_ranges ) ||
   1244          FT_FRAME_ENTER( num_ranges * 4L )      )
   1245       goto Exit;
   1246 
   1247     face->gasp.gaspRanges = gaspranges;
   1248 
   1249     for ( j = 0; j < num_ranges; j++ )
   1250     {
   1251       gaspranges[j].maxPPEM  = FT_GET_USHORT();
   1252       gaspranges[j].gaspFlag = FT_GET_USHORT();
   1253 
   1254       FT_TRACE3(( "gaspRange %d: rangeMaxPPEM %5d, rangeGaspBehavior 0x%x\n",
   1255                   j,
   1256                   gaspranges[j].maxPPEM,
   1257                   gaspranges[j].gaspFlag ));
   1258     }
   1259 
   1260     FT_FRAME_EXIT();
   1261 
   1262   Exit:
   1263     return error;
   1264   }
   1265 
   1266 
   1267 /* END */
   1268