misc/libfreetype/src/cache/ftccmap.c
changeset 5172 88f2e05288ba
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5171:f9283dc4860d 5172:88f2e05288ba
       
     1 /***************************************************************************/
       
     2 /*                                                                         */
       
     3 /*  ftccmap.c                                                              */
       
     4 /*                                                                         */
       
     5 /*    FreeType CharMap cache (body)                                        */
       
     6 /*                                                                         */
       
     7 /*  Copyright 2000-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,   */
       
     8 /*            2010, 2011 by                                                */
       
     9 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
       
    10 /*                                                                         */
       
    11 /*  This file is part of the FreeType project, and may only be used,       */
       
    12 /*  modified, and distributed under the terms of the FreeType project      */
       
    13 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
       
    14 /*  this file you indicate that you have read the license and              */
       
    15 /*  understand and accept it fully.                                        */
       
    16 /*                                                                         */
       
    17 /***************************************************************************/
       
    18 
       
    19 
       
    20 #include <ft2build.h>
       
    21 #include FT_FREETYPE_H
       
    22 #include FT_CACHE_H
       
    23 #include "ftcmanag.h"
       
    24 #include FT_INTERNAL_MEMORY_H
       
    25 #include FT_INTERNAL_OBJECTS_H
       
    26 #include FT_INTERNAL_DEBUG_H
       
    27 
       
    28 #include "ftccback.h"
       
    29 #include "ftcerror.h"
       
    30 
       
    31 #undef  FT_COMPONENT
       
    32 #define FT_COMPONENT  trace_cache
       
    33 
       
    34 
       
    35 #ifdef FT_CONFIG_OPTION_OLD_INTERNALS
       
    36 
       
    37   typedef enum  FTC_OldCMapType_
       
    38   {
       
    39     FTC_OLD_CMAP_BY_INDEX    = 0,
       
    40     FTC_OLD_CMAP_BY_ENCODING = 1,
       
    41     FTC_OLD_CMAP_BY_ID       = 2
       
    42 
       
    43   } FTC_OldCMapType;
       
    44 
       
    45 
       
    46   typedef struct  FTC_OldCMapIdRec_
       
    47   {
       
    48     FT_UInt  platform;
       
    49     FT_UInt  encoding;
       
    50 
       
    51   } FTC_OldCMapIdRec, *FTC_OldCMapId;
       
    52 
       
    53 
       
    54   typedef struct  FTC_OldCMapDescRec_
       
    55   {
       
    56     FTC_FaceID       face_id;
       
    57     FTC_OldCMapType  type;
       
    58 
       
    59     union
       
    60     {
       
    61       FT_UInt           index;
       
    62       FT_Encoding       encoding;
       
    63       FTC_OldCMapIdRec  id;
       
    64 
       
    65     } u;
       
    66 
       
    67   } FTC_OldCMapDescRec, *FTC_OldCMapDesc;
       
    68 
       
    69 #endif /* FT_CONFIG_OLD_INTERNALS */
       
    70 
       
    71 
       
    72   /*************************************************************************/
       
    73   /*                                                                       */
       
    74   /* Each FTC_CMapNode contains a simple array to map a range of character */
       
    75   /* codes to equivalent glyph indices.                                    */
       
    76   /*                                                                       */
       
    77   /* For now, the implementation is very basic: Each node maps a range of  */
       
    78   /* 128 consecutive character codes to their corresponding glyph indices. */
       
    79   /*                                                                       */
       
    80   /* We could do more complex things, but I don't think it is really very  */
       
    81   /* useful.                                                               */
       
    82   /*                                                                       */
       
    83   /*************************************************************************/
       
    84 
       
    85 
       
    86   /* number of glyph indices / character code per node */
       
    87 #define FTC_CMAP_INDICES_MAX  128
       
    88 
       
    89   /* compute a query/node hash */
       
    90 #define FTC_CMAP_HASH( faceid, index, charcode )         \
       
    91           ( _FTC_FACE_ID_HASH( faceid ) + 211 * (index) + \
       
    92             ( (charcode) / FTC_CMAP_INDICES_MAX )      )
       
    93 
       
    94   /* the charmap query */
       
    95   typedef struct  FTC_CMapQueryRec_
       
    96   {
       
    97     FTC_FaceID  face_id;
       
    98     FT_UInt     cmap_index;
       
    99     FT_UInt32   char_code;
       
   100 
       
   101   } FTC_CMapQueryRec, *FTC_CMapQuery;
       
   102 
       
   103 #define FTC_CMAP_QUERY( x )  ((FTC_CMapQuery)(x))
       
   104 #define FTC_CMAP_QUERY_HASH( x )                                         \
       
   105           FTC_CMAP_HASH( (x)->face_id, (x)->cmap_index, (x)->char_code )
       
   106 
       
   107   /* the cmap cache node */
       
   108   typedef struct  FTC_CMapNodeRec_
       
   109   {
       
   110     FTC_NodeRec  node;
       
   111     FTC_FaceID   face_id;
       
   112     FT_UInt      cmap_index;
       
   113     FT_UInt32    first;                         /* first character in node */
       
   114     FT_UInt16    indices[FTC_CMAP_INDICES_MAX]; /* array of glyph indices  */
       
   115 
       
   116   } FTC_CMapNodeRec, *FTC_CMapNode;
       
   117 
       
   118 #define FTC_CMAP_NODE( x ) ( (FTC_CMapNode)( x ) )
       
   119 #define FTC_CMAP_NODE_HASH( x )                                      \
       
   120           FTC_CMAP_HASH( (x)->face_id, (x)->cmap_index, (x)->first )
       
   121 
       
   122   /* if (indices[n] == FTC_CMAP_UNKNOWN), we assume that the corresponding */
       
   123   /* glyph indices haven't been queried through FT_Get_Glyph_Index() yet   */
       
   124 #define FTC_CMAP_UNKNOWN  ( (FT_UInt16)-1 )
       
   125 
       
   126 
       
   127   /*************************************************************************/
       
   128   /*************************************************************************/
       
   129   /*****                                                               *****/
       
   130   /*****                        CHARMAP NODES                          *****/
       
   131   /*****                                                               *****/
       
   132   /*************************************************************************/
       
   133   /*************************************************************************/
       
   134 
       
   135 
       
   136   FT_CALLBACK_DEF( void )
       
   137   ftc_cmap_node_free( FTC_Node   ftcnode,
       
   138                       FTC_Cache  cache )
       
   139   {
       
   140     FTC_CMapNode  node   = (FTC_CMapNode)ftcnode;
       
   141     FT_Memory     memory = cache->memory;
       
   142 
       
   143 
       
   144     FT_FREE( node );
       
   145   }
       
   146 
       
   147 
       
   148   /* initialize a new cmap node */
       
   149   FT_CALLBACK_DEF( FT_Error )
       
   150   ftc_cmap_node_new( FTC_Node   *ftcanode,
       
   151                      FT_Pointer  ftcquery,
       
   152                      FTC_Cache   cache )
       
   153   {
       
   154     FTC_CMapNode  *anode  = (FTC_CMapNode*)ftcanode;
       
   155     FTC_CMapQuery  query  = (FTC_CMapQuery)ftcquery;
       
   156     FT_Error       error;
       
   157     FT_Memory      memory = cache->memory;
       
   158     FTC_CMapNode   node   = NULL;
       
   159     FT_UInt        nn;
       
   160 
       
   161 
       
   162     if ( !FT_NEW( node ) )
       
   163     {
       
   164       node->face_id    = query->face_id;
       
   165       node->cmap_index = query->cmap_index;
       
   166       node->first      = (query->char_code / FTC_CMAP_INDICES_MAX) *
       
   167                          FTC_CMAP_INDICES_MAX;
       
   168 
       
   169       for ( nn = 0; nn < FTC_CMAP_INDICES_MAX; nn++ )
       
   170         node->indices[nn] = FTC_CMAP_UNKNOWN;
       
   171     }
       
   172 
       
   173     *anode = node;
       
   174     return error;
       
   175   }
       
   176 
       
   177 
       
   178   /* compute the weight of a given cmap node */
       
   179   FT_CALLBACK_DEF( FT_Offset )
       
   180   ftc_cmap_node_weight( FTC_Node   cnode,
       
   181                         FTC_Cache  cache )
       
   182   {
       
   183     FT_UNUSED( cnode );
       
   184     FT_UNUSED( cache );
       
   185 
       
   186     return sizeof ( *cnode );
       
   187   }
       
   188 
       
   189 
       
   190   /* compare a cmap node to a given query */
       
   191   FT_CALLBACK_DEF( FT_Bool )
       
   192   ftc_cmap_node_compare( FTC_Node    ftcnode,
       
   193                          FT_Pointer  ftcquery,
       
   194                          FTC_Cache   cache,
       
   195                          FT_Bool*    list_changed )
       
   196   {
       
   197     FTC_CMapNode   node  = (FTC_CMapNode)ftcnode;
       
   198     FTC_CMapQuery  query = (FTC_CMapQuery)ftcquery;
       
   199     FT_UNUSED( cache );
       
   200 
       
   201 
       
   202     if ( list_changed )
       
   203       *list_changed = FALSE;
       
   204     if ( node->face_id    == query->face_id    &&
       
   205          node->cmap_index == query->cmap_index )
       
   206     {
       
   207       FT_UInt32  offset = (FT_UInt32)( query->char_code - node->first );
       
   208 
       
   209 
       
   210       return FT_BOOL( offset < FTC_CMAP_INDICES_MAX );
       
   211     }
       
   212 
       
   213     return 0;
       
   214   }
       
   215 
       
   216 
       
   217   FT_CALLBACK_DEF( FT_Bool )
       
   218   ftc_cmap_node_remove_faceid( FTC_Node    ftcnode,
       
   219                                FT_Pointer  ftcface_id,
       
   220                                FTC_Cache   cache,
       
   221                                FT_Bool*    list_changed )
       
   222   {
       
   223     FTC_CMapNode  node    = (FTC_CMapNode)ftcnode;
       
   224     FTC_FaceID    face_id = (FTC_FaceID)ftcface_id;
       
   225     FT_UNUSED( cache );
       
   226 
       
   227 
       
   228     if ( list_changed )
       
   229       *list_changed = FALSE;
       
   230     return FT_BOOL( node->face_id == face_id );
       
   231   }
       
   232 
       
   233 
       
   234   /*************************************************************************/
       
   235   /*************************************************************************/
       
   236   /*****                                                               *****/
       
   237   /*****                    GLYPH IMAGE CACHE                          *****/
       
   238   /*****                                                               *****/
       
   239   /*************************************************************************/
       
   240   /*************************************************************************/
       
   241 
       
   242 
       
   243   FT_CALLBACK_TABLE_DEF
       
   244   const FTC_CacheClassRec  ftc_cmap_cache_class =
       
   245   {
       
   246     ftc_cmap_node_new,
       
   247     ftc_cmap_node_weight,
       
   248     ftc_cmap_node_compare,
       
   249     ftc_cmap_node_remove_faceid,
       
   250     ftc_cmap_node_free,
       
   251 
       
   252     sizeof ( FTC_CacheRec ),
       
   253     ftc_cache_init,
       
   254     ftc_cache_done,
       
   255   };
       
   256 
       
   257 
       
   258   /* documentation is in ftcache.h */
       
   259 
       
   260   FT_EXPORT_DEF( FT_Error )
       
   261   FTC_CMapCache_New( FTC_Manager     manager,
       
   262                      FTC_CMapCache  *acache )
       
   263   {
       
   264     return FTC_Manager_RegisterCache( manager,
       
   265                                       &ftc_cmap_cache_class,
       
   266                                       FTC_CACHE_P( acache ) );
       
   267   }
       
   268 
       
   269 
       
   270 #ifdef FT_CONFIG_OPTION_OLD_INTERNALS
       
   271 
       
   272   /*
       
   273    *  Unfortunately, it is not possible to support binary backwards
       
   274    *  compatibility in the cmap cache.  The FTC_CMapCache_Lookup signature
       
   275    *  changes were too deep, and there is no clever hackish way to detect
       
   276    *  what kind of structure we are being passed.
       
   277    *
       
   278    *  On the other hand it seems that no production code is using this
       
   279    *  function on Unix distributions.
       
   280    */
       
   281 
       
   282 #endif
       
   283 
       
   284 
       
   285   /* documentation is in ftcache.h */
       
   286 
       
   287   FT_EXPORT_DEF( FT_UInt )
       
   288   FTC_CMapCache_Lookup( FTC_CMapCache  cmap_cache,
       
   289                         FTC_FaceID     face_id,
       
   290                         FT_Int         cmap_index,
       
   291                         FT_UInt32      char_code )
       
   292   {
       
   293     FTC_Cache         cache = FTC_CACHE( cmap_cache );
       
   294     FTC_CMapQueryRec  query;
       
   295     FTC_Node          node;
       
   296     FT_Error          error;
       
   297     FT_UInt           gindex = 0;
       
   298     FT_PtrDist        hash;
       
   299     FT_Int            no_cmap_change = 0;
       
   300 
       
   301 
       
   302     if ( cmap_index < 0 )
       
   303     {
       
   304       /* Treat a negative cmap index as a special value, meaning that you */
       
   305       /* don't want to change the FT_Face's character map through this    */
       
   306       /* call.  This can be useful if the face requester callback already */
       
   307       /* sets the face's charmap to the appropriate value.                */
       
   308 
       
   309       no_cmap_change = 1;
       
   310       cmap_index     = 0;
       
   311     }
       
   312 
       
   313     if ( !cache )
       
   314     {
       
   315       FT_TRACE0(( "FTC_CMapCache_Lookup: bad arguments, returning 0\n" ));
       
   316       return 0;
       
   317     }
       
   318 
       
   319 #ifdef FT_CONFIG_OPTION_OLD_INTERNALS
       
   320 
       
   321     /*
       
   322      * If cmap_index is greater than the maximum number of cachable
       
   323      * charmaps, we assume the request is from a legacy rogue client 
       
   324      * using old internal header. See include/config/ftoption.h.
       
   325      */
       
   326     if ( cmap_index > FT_MAX_CHARMAP_CACHEABLE && !no_cmap_change )
       
   327     {
       
   328       FTC_OldCMapDesc  desc = (FTC_OldCMapDesc) face_id;
       
   329 
       
   330 
       
   331       char_code     = (FT_UInt32)cmap_index;
       
   332       query.face_id = desc->face_id;
       
   333 
       
   334 
       
   335       switch ( desc->type )
       
   336       {
       
   337       case FTC_OLD_CMAP_BY_INDEX:
       
   338         query.cmap_index = desc->u.index;
       
   339         query.char_code  = (FT_UInt32)cmap_index;
       
   340         break;
       
   341 
       
   342       case FTC_OLD_CMAP_BY_ENCODING:
       
   343         {
       
   344           FT_Face  face;
       
   345 
       
   346 
       
   347           error = FTC_Manager_LookupFace( cache->manager, desc->face_id,
       
   348                                           &face );
       
   349           if ( error )
       
   350             return 0;
       
   351 
       
   352           FT_Select_Charmap( face, desc->u.encoding );
       
   353 
       
   354           return FT_Get_Char_Index( face, char_code );
       
   355         }
       
   356 
       
   357       default:
       
   358         return 0;
       
   359       }
       
   360     }
       
   361     else
       
   362 
       
   363 #endif /* FT_CONFIG_OPTION_OLD_INTERNALS */
       
   364 
       
   365     {
       
   366       query.face_id    = face_id;
       
   367       query.cmap_index = (FT_UInt)cmap_index;
       
   368       query.char_code  = char_code;
       
   369     }
       
   370 
       
   371     hash = FTC_CMAP_HASH( face_id, cmap_index, char_code );
       
   372 
       
   373 #if 1
       
   374     FTC_CACHE_LOOKUP_CMP( cache, ftc_cmap_node_compare, hash, &query,
       
   375                           node, error );
       
   376 #else
       
   377     error = FTC_Cache_Lookup( cache, hash, &query, &node );
       
   378 #endif
       
   379     if ( error )
       
   380       goto Exit;
       
   381 
       
   382     FT_ASSERT( (FT_UInt)( char_code - FTC_CMAP_NODE( node )->first ) <
       
   383                 FTC_CMAP_INDICES_MAX );
       
   384 
       
   385     /* something rotten can happen with rogue clients */
       
   386     if ( (FT_UInt)( char_code - FTC_CMAP_NODE( node )->first >=
       
   387                     FTC_CMAP_INDICES_MAX ) )
       
   388       return 0; /* XXX: should return appropriate error */
       
   389 
       
   390     gindex = FTC_CMAP_NODE( node )->indices[char_code -
       
   391                                             FTC_CMAP_NODE( node )->first];
       
   392     if ( gindex == FTC_CMAP_UNKNOWN )
       
   393     {
       
   394       FT_Face  face;
       
   395 
       
   396 
       
   397       gindex = 0;
       
   398 
       
   399       error = FTC_Manager_LookupFace( cache->manager,
       
   400                                       FTC_CMAP_NODE( node )->face_id,
       
   401                                       &face );
       
   402       if ( error )
       
   403         goto Exit;
       
   404 
       
   405 #ifdef FT_MAX_CHARMAP_CACHEABLE
       
   406       /* something rotten can happen with rogue clients */
       
   407       if ( cmap_index > FT_MAX_CHARMAP_CACHEABLE )
       
   408         return 0; /* XXX: should return appropriate error */
       
   409 #endif
       
   410 
       
   411       if ( (FT_UInt)cmap_index < (FT_UInt)face->num_charmaps )
       
   412       {
       
   413         FT_CharMap  old, cmap  = NULL;
       
   414 
       
   415 
       
   416         old  = face->charmap;
       
   417         cmap = face->charmaps[cmap_index];
       
   418 
       
   419         if ( old != cmap && !no_cmap_change )
       
   420           FT_Set_Charmap( face, cmap );
       
   421 
       
   422         gindex = FT_Get_Char_Index( face, char_code );
       
   423 
       
   424         if ( old != cmap && !no_cmap_change )
       
   425           FT_Set_Charmap( face, old );
       
   426       }
       
   427 
       
   428       FTC_CMAP_NODE( node )->indices[char_code -
       
   429                                      FTC_CMAP_NODE( node )->first]
       
   430         = (FT_UShort)gindex;
       
   431     }
       
   432 
       
   433   Exit:
       
   434     return gindex;
       
   435   }
       
   436 
       
   437 
       
   438 /* END */