aboutsummaryrefslogtreecommitdiff
path: root/freetype/src/cache/ftccmap.c
blob: 226c0015cf231a67ab5c3786ac634078e3eff619 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
/***************************************************************************/
/*                                                                         */
/*  ftccmap.c                                                              */
/*                                                                         */
/*    FreeType CharMap cache (body)                                        */
/*                                                                         */
/*  Copyright 2000-2012 by                                                 */
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used,       */
/*  modified, and distributed under the terms of the FreeType project      */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/


#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_CACHE_H
#include "ftcmanag.h"
#include FT_INTERNAL_MEMORY_H
#include FT_INTERNAL_OBJECTS_H
#include FT_INTERNAL_DEBUG_H

#include "ftccback.h"
#include "ftcerror.h"

#undef  FT_COMPONENT
#define FT_COMPONENT  trace_cache


#ifdef FT_CONFIG_OPTION_OLD_INTERNALS

  typedef enum  FTC_OldCMapType_
  {
    FTC_OLD_CMAP_BY_INDEX    = 0,
    FTC_OLD_CMAP_BY_ENCODING = 1,
    FTC_OLD_CMAP_BY_ID       = 2

  } FTC_OldCMapType;


  typedef struct  FTC_OldCMapIdRec_
  {
    FT_UInt  platform;
    FT_UInt  encoding;

  } FTC_OldCMapIdRec, *FTC_OldCMapId;


  typedef struct  FTC_OldCMapDescRec_
  {
    FTC_FaceID       face_id;
    FTC_OldCMapType  type;

    union
    {
      FT_UInt           index;
      FT_Encoding       encoding;
      FTC_OldCMapIdRec  id;

    } u;

  } FTC_OldCMapDescRec, *FTC_OldCMapDesc;

#endif /* FT_CONFIG_OLD_INTERNALS */


  /*************************************************************************/
  /*                                                                       */
  /* Each FTC_CMapNode contains a simple array to map a range of character */
  /* codes to equivalent glyph indices.                                    */
  /*                                                                       */
  /* For now, the implementation is very basic: Each node maps a range of  */
  /* 128 consecutive character codes to their corresponding glyph indices. */
  /*                                                                       */
  /* We could do more complex things, but I don't think it is really very  */
  /* useful.                                                               */
  /*                                                                       */
  /*************************************************************************/


  /* number of glyph indices / character code per node */
#define FTC_CMAP_INDICES_MAX  128

  /* compute a query/node hash */
#define FTC_CMAP_HASH( faceid, index, charcode )         \
          ( _FTC_FACE_ID_HASH( faceid ) + 211 * (index) + \
            ( (charcode) / FTC_CMAP_INDICES_MAX )      )

  /* the charmap query */
  typedef struct  FTC_CMapQueryRec_
  {
    FTC_FaceID  face_id;
    FT_UInt     cmap_index;
    FT_UInt32   char_code;

  } FTC_CMapQueryRec, *FTC_CMapQuery;

#define FTC_CMAP_QUERY( x )  ((FTC_CMapQuery)(x))
#define FTC_CMAP_QUERY_HASH( x )                                         \
          FTC_CMAP_HASH( (x)->face_id, (x)->cmap_index, (x)->char_code )

  /* the cmap cache node */
  typedef struct  FTC_CMapNodeRec_
  {
    FTC_NodeRec  node;
    FTC_FaceID   face_id;
    FT_UInt      cmap_index;
    FT_UInt32    first;                         /* first character in node */
    FT_UInt16    indices[FTC_CMAP_INDICES_MAX]; /* array of glyph indices  */

  } FTC_CMapNodeRec, *FTC_CMapNode;

#define FTC_CMAP_NODE( x ) ( (FTC_CMapNode)( x ) )
#define FTC_CMAP_NODE_HASH( x )                                      \
          FTC_CMAP_HASH( (x)->face_id, (x)->cmap_index, (x)->first )

  /* if (indices[n] == FTC_CMAP_UNKNOWN), we assume that the corresponding */
  /* glyph indices haven't been queried through FT_Get_Glyph_Index() yet   */
#define FTC_CMAP_UNKNOWN  (FT_UInt16)~0


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                        CHARMAP NODES                          *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/


  FT_CALLBACK_DEF( void )
  ftc_cmap_node_free( FTC_Node   ftcnode,
                      FTC_Cache  cache )
  {
    FTC_CMapNode  node   = (FTC_CMapNode)ftcnode;
    FT_Memory     memory = cache->memory;


    FT_FREE( node );
  }


  /* initialize a new cmap node */
  FT_CALLBACK_DEF( FT_Error )
  ftc_cmap_node_new( FTC_Node   *ftcanode,
                     FT_Pointer  ftcquery,
                     FTC_Cache   cache )
  {
    FTC_CMapNode  *anode  = (FTC_CMapNode*)ftcanode;
    FTC_CMapQuery  query  = (FTC_CMapQuery)ftcquery;
    FT_Error       error;
    FT_Memory      memory = cache->memory;
    FTC_CMapNode   node   = NULL;
    FT_UInt        nn;


    if ( !FT_NEW( node ) )
    {
      node->face_id    = query->face_id;
      node->cmap_index = query->cmap_index;
      node->first      = (query->char_code / FTC_CMAP_INDICES_MAX) *
                         FTC_CMAP_INDICES_MAX;

      for ( nn = 0; nn < FTC_CMAP_INDICES_MAX; nn++ )
        node->indices[nn] = FTC_CMAP_UNKNOWN;
    }

    *anode = node;
    return error;
  }


  /* compute the weight of a given cmap node */
  FT_CALLBACK_DEF( FT_Offset )
  ftc_cmap_node_weight( FTC_Node   cnode,
                        FTC_Cache  cache )
  {
    FT_UNUSED( cnode );
    FT_UNUSED( cache );

    return sizeof ( *cnode );
  }


  /* compare a cmap node to a given query */
  FT_CALLBACK_DEF( FT_Bool )
  ftc_cmap_node_compare( FTC_Node    ftcnode,
                         FT_Pointer  ftcquery,
                         FTC_Cache   cache,
                         FT_Bool*    list_changed )
  {
    FTC_CMapNode   node  = (FTC_CMapNode)ftcnode;
    FTC_CMapQuery  query = (FTC_CMapQuery)ftcquery;
    FT_UNUSED( cache );


    if ( list_changed )
      *list_changed = FALSE;
    if ( node->face_id    == query->face_id    &&
         node->cmap_index == query->cmap_index )
    {
      FT_UInt32  offset = (FT_UInt32)( query->char_code - node->first );


      return FT_BOOL( offset < FTC_CMAP_INDICES_MAX );
    }

    return 0;
  }


  FT_CALLBACK_DEF( FT_Bool )
  ftc_cmap_node_remove_faceid( FTC_Node    ftcnode,
                               FT_Pointer  ftcface_id,
                               FTC_Cache   cache,
                               FT_Bool*    list_changed )
  {
    FTC_CMapNode  node    = (FTC_CMapNode)ftcnode;
    FTC_FaceID    face_id = (FTC_FaceID)ftcface_id;
    FT_UNUSED( cache );


    if ( list_changed )
      *list_changed = FALSE;
    return FT_BOOL( node->face_id == face_id );
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                    GLYPH IMAGE CACHE                          *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/


  FT_CALLBACK_TABLE_DEF
  const FTC_CacheClassRec  ftc_cmap_cache_class =
  {
    ftc_cmap_node_new,
    ftc_cmap_node_weight,
    ftc_cmap_node_compare,
    ftc_cmap_node_remove_faceid,
    ftc_cmap_node_free,

    sizeof ( FTC_CacheRec ),
    ftc_cache_init,
    ftc_cache_done,
  };


  /* documentation is in ftcache.h */

  FT_EXPORT_DEF( FT_Error )
  FTC_CMapCache_New( FTC_Manager     manager,
                     FTC_CMapCache  *acache )
  {
    return FTC_Manager_RegisterCache( manager,
                                      &ftc_cmap_cache_class,
                                      FTC_CACHE_P( acache ) );
  }


#ifdef FT_CONFIG_OPTION_OLD_INTERNALS

  /*
   *  Unfortunately, it is not possible to support binary backwards
   *  compatibility in the cmap cache.  The FTC_CMapCache_Lookup signature
   *  changes were too deep, and there is no clever hackish way to detect
   *  what kind of structure we are being passed.
   *
   *  On the other hand it seems that no production code is using this
   *  function on Unix distributions.
   */

#endif


  /* documentation is in ftcache.h */

  FT_EXPORT_DEF( FT_UInt )
  FTC_CMapCache_Lookup( FTC_CMapCache  cmap_cache,
                        FTC_FaceID     face_id,
                        FT_Int         cmap_index,
                        FT_UInt32      char_code )
  {
    FTC_Cache         cache = FTC_CACHE( cmap_cache );
    FTC_CMapQueryRec  query;
    FTC_Node          node;
    FT_Error          error;
    FT_UInt           gindex = 0;
    FT_PtrDist        hash;
    FT_Int            no_cmap_change = 0;


    if ( cmap_index < 0 )
    {
      /* Treat a negative cmap index as a special value, meaning that you */
      /* don't want to change the FT_Face's character map through this    */
      /* call.  This can be useful if the face requester callback already */
      /* sets the face's charmap to the appropriate value.                */

      no_cmap_change = 1;
      cmap_index     = 0;
    }

    if ( !cache )
    {
      FT_TRACE0(( "FTC_CMapCache_Lookup: bad arguments, returning 0\n" ));
      return 0;
    }

#ifdef FT_CONFIG_OPTION_OLD_INTERNALS

    /*
     * If cmap_index is greater than the maximum number of cachable
     * charmaps, we assume the request is from a legacy rogue client
     * using old internal header. See include/config/ftoption.h.
     */
    if ( cmap_index > FT_MAX_CHARMAP_CACHEABLE && !no_cmap_change )
    {
      FTC_OldCMapDesc  desc = (FTC_OldCMapDesc) face_id;


      char_code     = (FT_UInt32)cmap_index;
      query.face_id = desc->face_id;


      switch ( desc->type )
      {
      case FTC_OLD_CMAP_BY_INDEX:
        query.cmap_index = desc->u.index;
        query.char_code  = (FT_UInt32)cmap_index;
        break;

      case FTC_OLD_CMAP_BY_ENCODING:
        {
          FT_Face  face;


          error = FTC_Manager_LookupFace( cache->manager, desc->face_id,
                                          &face );
          if ( error )
            return 0;

          FT_Select_Charmap( face, desc->u.encoding );

          return FT_Get_Char_Index( face, char_code );
        }

      default:
        return 0;
      }
    }
    else

#endif /* FT_CONFIG_OPTION_OLD_INTERNALS */

    {
      query.face_id    = face_id;
      query.cmap_index = (FT_UInt)cmap_index;
      query.char_code  = char_code;
    }

    hash = FTC_CMAP_HASH( face_id, cmap_index, char_code );

#if 1
    FTC_CACHE_LOOKUP_CMP( cache, ftc_cmap_node_compare, hash, &query,
                          node, error );
#else
    error = FTC_Cache_Lookup( cache, hash, &query, &node );
#endif
    if ( error )
      goto Exit;

    FT_ASSERT( (FT_UInt)( char_code - FTC_CMAP_NODE( node )->first ) <
                FTC_CMAP_INDICES_MAX );

    /* something rotten can happen with rogue clients */
    if ( (FT_UInt)( char_code - FTC_CMAP_NODE( node )->first >=
                    FTC_CMAP_INDICES_MAX ) )
      return 0; /* XXX: should return appropriate error */

    gindex = FTC_CMAP_NODE( node )->indices[char_code -
                                            FTC_CMAP_NODE( node )->first];
    if ( gindex == FTC_CMAP_UNKNOWN )
    {
      FT_Face  face;


      gindex = 0;

      error = FTC_Manager_LookupFace( cache->manager,
                                      FTC_CMAP_NODE( node )->face_id,
                                      &face );
      if ( error )
        goto Exit;

#ifdef FT_MAX_CHARMAP_CACHEABLE
      /* something rotten can happen with rogue clients */
      if ( cmap_index > FT_MAX_CHARMAP_CACHEABLE )
        return 0; /* XXX: should return appropriate error */
#endif

      if ( (FT_UInt)cmap_index < (FT_UInt)face->num_charmaps )
      {
        FT_CharMap  old, cmap  = NULL;


        old  = face->charmap;
        cmap = face->charmaps[cmap_index];

        if ( old != cmap && !no_cmap_change )
          FT_Set_Charmap( face, cmap );

        gindex = FT_Get_Char_Index( face, char_code );

        if ( old != cmap && !no_cmap_change )
          FT_Set_Charmap( face, old );
      }

      FTC_CMAP_NODE( node )->indices[char_code -
                                     FTC_CMAP_NODE( node )->first]
        = (FT_UShort)gindex;
    }

  Exit:
    return gindex;
  }


/* END */