reactos/sdk/lib/3rdparty/freetype/src/cache/ftccmap.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  ftccmap.c                                                              */
   4 /*                                                                         */
   5 /*    FreeType CharMap cache (body)                                        */
   6 /*                                                                         */
   7 /*  Copyright 2000-2016 by                                                 */
   8 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
   9 /*                                                                         */
  10 /*  This file is part of the FreeType project, and may only be used,       */
  11 /*  modified, and distributed under the terms of the FreeType project      */
  12 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
  13 /*  this file you indicate that you have read the license and              */
  14 /*  understand and accept it fully.                                        */
  15 /*                                                                         */
  16 /***************************************************************************/
  17
  18
  19 #include <ft2build.h>
  20 #include FT_FREETYPE_H
  21 #include FT_CACHE_H
  22 #include "ftcmanag.h"
  23 #include FT_INTERNAL_MEMORY_H
  24 #include FT_INTERNAL_OBJECTS_H
  25 #include FT_INTERNAL_DEBUG_H
  26
  27 #include "ftccback.h"
  28 #include "ftcerror.h"
  29
  30 #undef  FT_COMPONENT
  31 #define FT_COMPONENT  trace_cache
  32
  33
  34   /*************************************************************************/
  35   /*                                                                       */
  36   /* Each FTC_CMapNode contains a simple array to map a range of character */
  37   /* codes to equivalent glyph indices.                                    */
  38   /*                                                                       */
  39   /* For now, the implementation is very basic: Each node maps a range of  */
  40   /* 128 consecutive character codes to their corresponding glyph indices. */
  41   /*                                                                       */
  42   /* We could do more complex things, but I don't think it is really very  */
  43   /* useful.                                                               */
  44   /*                                                                       */
  45   /*************************************************************************/
  46
  47
  48   /* number of glyph indices / character code per node */
  49 #define FTC_CMAP_INDICES_MAX  128
  50
  51   /* compute a query/node hash */
  52 #define FTC_CMAP_HASH( faceid, index, charcode )         \
  53           ( FTC_FACE_ID_HASH( faceid ) + 211 * (index) + \
  54             ( (charcode) / FTC_CMAP_INDICES_MAX )      )
  55
  56   /* the charmap query */
  57   typedef struct  FTC_CMapQueryRec_
  58   {
  59     FTC_FaceID  face_id;
  60     FT_UInt     cmap_index;
  61     FT_UInt32   char_code;
  62
  63   } FTC_CMapQueryRec, *FTC_CMapQuery;
  64
  65 #define FTC_CMAP_QUERY( x )  ((FTC_CMapQuery)(x))
  66
  67   /* the cmap cache node */
  68   typedef struct  FTC_CMapNodeRec_
  69   {
  70     FTC_NodeRec  node;
  71     FTC_FaceID   face_id;
  72     FT_UInt      cmap_index;
  73     FT_UInt32    first;                         /* first character in node */
  74     FT_UInt16    indices[FTC_CMAP_INDICES_MAX]; /* array of glyph indices  */
  75
  76   } FTC_CMapNodeRec, *FTC_CMapNode;
  77
  78 #define FTC_CMAP_NODE( x ) ( (FTC_CMapNode)( x ) )
  79
  80   /* if (indices[n] == FTC_CMAP_UNKNOWN), we assume that the corresponding */
  81   /* glyph indices haven't been queried through FT_Get_Glyph_Index() yet   */
  82 #define FTC_CMAP_UNKNOWN  (FT_UInt16)~0
  83
  84
  85   /*************************************************************************/
  86   /*************************************************************************/
  87   /*****                                                               *****/
  88   /*****                        CHARMAP NODES                          *****/
  89   /*****                                                               *****/
  90   /*************************************************************************/
  91   /*************************************************************************/
  92
  93
  94   FT_CALLBACK_DEF( void )
  95   ftc_cmap_node_free( FTC_Node   ftcnode,
  96                       FTC_Cache  cache )
  97   {
  98     FTC_CMapNode  node   = (FTC_CMapNode)ftcnode;
  99     FT_Memory     memory = cache->memory;
 100
 101
 102     FT_FREE( node );
 103   }
 104
 105
 106   /* initialize a new cmap node */
 107   FT_CALLBACK_DEF( FT_Error )
 108   ftc_cmap_node_new( FTC_Node   *ftcanode,
 109                      FT_Pointer  ftcquery,
 110                      FTC_Cache   cache )
 111   {
 112     FTC_CMapNode  *anode  = (FTC_CMapNode*)ftcanode;
 113     FTC_CMapQuery  query  = (FTC_CMapQuery)ftcquery;
 114     FT_Error       error;
 115     FT_Memory      memory = cache->memory;
 116     FTC_CMapNode   node   = NULL;
 117     FT_UInt        nn;
 118
 119
 120     if ( !FT_NEW( node ) )
 121     {
 122       node->face_id    = query->face_id;
 123       node->cmap_index = query->cmap_index;
 124       node->first      = (query->char_code / FTC_CMAP_INDICES_MAX) *
 125                          FTC_CMAP_INDICES_MAX;
 126
 127       for ( nn = 0; nn < FTC_CMAP_INDICES_MAX; nn++ )
 128         node->indices[nn] = FTC_CMAP_UNKNOWN;
 129     }
 130
 131     *anode = node;
 132     return error;
 133   }
 134
 135
 136   /* compute the weight of a given cmap node */
 137   FT_CALLBACK_DEF( FT_Offset )
 138   ftc_cmap_node_weight( FTC_Node   cnode,
 139                         FTC_Cache  cache )
 140   {
 141     FT_UNUSED( cnode );
 142     FT_UNUSED( cache );
 143
 144     return sizeof ( *cnode );
 145   }
 146
 147
 148   /* compare a cmap node to a given query */
 149   FT_CALLBACK_DEF( FT_Bool )
 150   ftc_cmap_node_compare( FTC_Node    ftcnode,
 151                          FT_Pointer  ftcquery,
 152                          FTC_Cache   cache,
 153                          FT_Bool*    list_changed )
 154   {
 155     FTC_CMapNode   node  = (FTC_CMapNode)ftcnode;
 156     FTC_CMapQuery  query = (FTC_CMapQuery)ftcquery;
 157     FT_UNUSED( cache );
 158
 159
 160     if ( list_changed )
 161       *list_changed = FALSE;
 162     if ( node->face_id    == query->face_id    &&
 163          node->cmap_index == query->cmap_index )
 164     {
 165       FT_UInt32  offset = (FT_UInt32)( query->char_code - node->first );
 166
 167
 168       return FT_BOOL( offset < FTC_CMAP_INDICES_MAX );
 169     }
 170
 171     return 0;
 172   }
 173
 174
 175   FT_CALLBACK_DEF( FT_Bool )
 176   ftc_cmap_node_remove_faceid( FTC_Node    ftcnode,
 177                                FT_Pointer  ftcface_id,
 178                                FTC_Cache   cache,
 179                                FT_Bool*    list_changed )
 180   {
 181     FTC_CMapNode  node    = (FTC_CMapNode)ftcnode;
 182     FTC_FaceID    face_id = (FTC_FaceID)ftcface_id;
 183     FT_UNUSED( cache );
 184
 185
 186     if ( list_changed )
 187       *list_changed = FALSE;
 188     return FT_BOOL( node->face_id == face_id );
 189   }
 190
 191
 192   /*************************************************************************/
 193   /*************************************************************************/
 194   /*****                                                               *****/
 195   /*****                    GLYPH IMAGE CACHE                          *****/
 196   /*****                                                               *****/
 197   /*************************************************************************/
 198   /*************************************************************************/
 199
 200
 201   static
 202   const FTC_CacheClassRec  ftc_cmap_cache_class =
 203   {
 204     ftc_cmap_node_new,
 205     ftc_cmap_node_weight,
 206     ftc_cmap_node_compare,
 207     ftc_cmap_node_remove_faceid,
 208     ftc_cmap_node_free,
 209
 210     sizeof ( FTC_CacheRec ),
 211     ftc_cache_init,
 212     ftc_cache_done,
 213   };
 214
 215
 216   /* documentation is in ftcache.h */
 217
 218   FT_EXPORT_DEF( FT_Error )
 219   FTC_CMapCache_New( FTC_Manager     manager,
 220                      FTC_CMapCache  *acache )
 221   {
 222     return FTC_Manager_RegisterCache( manager,
 223                                       &ftc_cmap_cache_class,
 224                                       FTC_CACHE_P( acache ) );
 225   }
 226
 227
 228   /* documentation is in ftcache.h */
 229
 230   FT_EXPORT_DEF( FT_UInt )
 231   FTC_CMapCache_Lookup( FTC_CMapCache  cmap_cache,
 232                         FTC_FaceID     face_id,
 233                         FT_Int         cmap_index,
 234                         FT_UInt32      char_code )
 235   {
 236     FTC_Cache         cache = FTC_CACHE( cmap_cache );
 237     FTC_CMapQueryRec  query;
 238     FTC_Node          node;
 239     FT_Error          error;
 240     FT_UInt           gindex = 0;
 241     FT_Offset         hash;
 242     FT_Int            no_cmap_change = 0;
 243
 244
 245     if ( cmap_index < 0 )
 246     {
 247       /* Treat a negative cmap index as a special value, meaning that you */
 248       /* don't want to change the FT_Face's character map through this    */
 249       /* call.  This can be useful if the face requester callback already */
 250       /* sets the face's charmap to the appropriate value.                */
 251
 252       no_cmap_change = 1;
 253       cmap_index     = 0;
 254     }
 255
 256     if ( !cache )
 257     {
 258       FT_TRACE0(( "FTC_CMapCache_Lookup: bad arguments, returning 0\n" ));
 259       return 0;
 260     }
 261
 262     query.face_id    = face_id;
 263     query.cmap_index = (FT_UInt)cmap_index;
 264     query.char_code  = char_code;
 265
 266     hash = FTC_CMAP_HASH( face_id, (FT_UInt)cmap_index, char_code );
 267
 268 #if 1
 269     FTC_CACHE_LOOKUP_CMP( cache, ftc_cmap_node_compare, hash, &query,
 270                           node, error );
 271 #else
 272     error = FTC_Cache_Lookup( cache, hash, &query, &node );
 273 #endif
 274     if ( error )
 275       goto Exit;
 276
 277     FT_ASSERT( (FT_UInt)( char_code - FTC_CMAP_NODE( node )->first ) <
 278                 FTC_CMAP_INDICES_MAX );
 279
 280     /* something rotten can happen with rogue clients */
 281     if ( (FT_UInt)( char_code - FTC_CMAP_NODE( node )->first >=
 282                     FTC_CMAP_INDICES_MAX ) )
 283       return 0; /* XXX: should return appropriate error */
 284
 285     gindex = FTC_CMAP_NODE( node )->indices[char_code -
 286                                             FTC_CMAP_NODE( node )->first];
 287     if ( gindex == FTC_CMAP_UNKNOWN )
 288     {
 289       FT_Face  face;
 290
 291
 292       gindex = 0;
 293
 294       error = FTC_Manager_LookupFace( cache->manager,
 295                                       FTC_CMAP_NODE( node )->face_id,
 296                                       &face );
 297       if ( error )
 298         goto Exit;
 299
 300       if ( (FT_UInt)cmap_index < (FT_UInt)face->num_charmaps )
 301       {
 302         FT_CharMap  old, cmap  = NULL;
 303
 304
 305         old  = face->charmap;
 306         cmap = face->charmaps[cmap_index];
 307
 308         if ( old != cmap && !no_cmap_change )
 309           FT_Set_Charmap( face, cmap );
 310
 311         gindex = FT_Get_Char_Index( face, char_code );
 312
 313         if ( old != cmap && !no_cmap_change )
 314           FT_Set_Charmap( face, old );
 315       }
 316
 317       FTC_CMAP_NODE( node )->indices[char_code -
 318                                      FTC_CMAP_NODE( node )->first]
 319         = (FT_UShort)gindex;
 320     }
 321
 322   Exit:
 323     return gindex;
 324   }
 325
 326
 327 /* END */