src/hb-shape-plan.cc

   1 /*
   2  * Copyright © 2012  Google, Inc.
   3  *
   4  *  This is part of HarfBuzz, a text shaping library.
   5  *
   6  * Permission is hereby granted, without written agreement and without
   7  * license or royalty fees, to use, copy, modify, and distribute this
   8  * software and its documentation for any purpose, provided that the
   9  * above copyright notice and the following two paragraphs appear in
  10  * all copies of this software.
  11  *
  12  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  13  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  14  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  15  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  16  * DAMAGE.
  17  *
  18  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  19  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  20  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  21  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  22  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  23  *
  24  * Google Author(s): Behdad Esfahbod
  25  */
  26
  27 #include "hb-shape-plan-private.hh"
  28 #include "hb-shaper-private.hh"
  29 #include "hb-font-private.hh"
  30 #include "hb-buffer-private.hh"
  31
  32
  33 #ifndef HB_DEBUG_SHAPE_PLAN
  34 #define HB_DEBUG_SHAPE_PLAN (HB_DEBUG+0)
  35 #endif
  36
  37
  38 #define HB_SHAPER_IMPLEMENT(shaper) \
  39         HB_SHAPER_DATA_ENSURE_DECLARE(shaper, face) \
  40         HB_SHAPER_DATA_ENSURE_DECLARE(shaper, font)
  41 #include "hb-shaper-list.hh"
  42 #undef HB_SHAPER_IMPLEMENT
  43
  44
  45 static void
  46 hb_shape_plan_plan (hb_shape_plan_t    *shape_plan,
  47                     const hb_feature_t *user_features,
  48                     unsigned int        num_user_features,
  49                     const char * const *shaper_list)
  50 {
  51   DEBUG_MSG_FUNC (SHAPE_PLAN, shape_plan,
  52                   "num_features=%d shaper_list=%p",
  53                   num_user_features,
  54                   shaper_list);
  55
  56   const hb_shaper_pair_t *shapers = _hb_shapers_get ();
  57
  58 #define HB_SHAPER_PLAN(shaper) \
  59         HB_STMT_START { \
  60           if (hb_##shaper##_shaper_face_data_ensure (shape_plan->face_unsafe)) { \
  61             HB_SHAPER_DATA (shaper, shape_plan) = \
  62               HB_SHAPER_DATA_CREATE_FUNC (shaper, shape_plan) (shape_plan, user_features, num_user_features); \
  63             shape_plan->shaper_func = _hb_##shaper##_shape; \
  64             shape_plan->shaper_name = #shaper; \
  65             return; \
  66           } \
  67         } HB_STMT_END
  68
  69   if (likely (!shaper_list)) {
  70     for (unsigned int i = 0; i < HB_SHAPERS_COUNT; i++)
  71       if (0)
  72         ;
  73 #define HB_SHAPER_IMPLEMENT(shaper) \
  74       else if (shapers[i].func == _hb_##shaper##_shape) \
  75         HB_SHAPER_PLAN (shaper);
  76 #include "hb-shaper-list.hh"
  77 #undef HB_SHAPER_IMPLEMENT
  78   } else {
  79     for (; *shaper_list; shaper_list++)
  80       if (0)
  81         ;
  82 #define HB_SHAPER_IMPLEMENT(shaper) \
  83       else if (0 == strcmp (*shaper_list, #shaper)) \
  84         HB_SHAPER_PLAN (shaper);
  85 #include "hb-shaper-list.hh"
  86 #undef HB_SHAPER_IMPLEMENT
  87   }
  88
  89 #undef HB_SHAPER_PLAN
  90 }
  91
  92
  93 /*
  94  * hb_shape_plan_t
  95  */
  96
  97 /**
  98  * hb_shape_plan_create: (Xconstructor)
  99  * @face:
 100  * @props:
 101  * @user_features: (array length=num_user_features):
 102  * @num_user_features:
 103  * @shaper_list: (array zero-terminated=1):
 104  *
 105  *
 106  *
 107  * Return value: (transfer full):
 108  *
 109  * Since: 1.0
 110  **/
 111 hb_shape_plan_t *
 112 hb_shape_plan_create (hb_face_t                     *face,
 113                       const hb_segment_properties_t *props,
 114                       const hb_feature_t            *user_features,
 115                       unsigned int                   num_user_features,
 116                       const char * const            *shaper_list)
 117 {
 118   DEBUG_MSG_FUNC (SHAPE_PLAN, NULL,
 119                   "face=%p num_features=%d shaper_list=%p",
 120                   face,
 121                   num_user_features,
 122                   shaper_list);
 123
 124   hb_shape_plan_t *shape_plan;
 125   hb_feature_t *features = NULL;
 126
 127   if (unlikely (!face))
 128     face = hb_face_get_empty ();
 129   if (unlikely (!props || hb_object_is_inert (face)))
 130     return hb_shape_plan_get_empty ();
 131   if (num_user_features && !(features = (hb_feature_t *) malloc (num_user_features * sizeof (hb_feature_t))))
 132     return hb_shape_plan_get_empty ();
 133   if (!(shape_plan = hb_object_create<hb_shape_plan_t> ())) {
 134     free (features);
 135     return hb_shape_plan_get_empty ();
 136   }
 137
 138   assert (props->direction != HB_DIRECTION_INVALID);
 139
 140   hb_face_make_immutable (face);
 141   shape_plan->default_shaper_list = shaper_list == NULL;
 142   shape_plan->face_unsafe = face;
 143   shape_plan->props = *props;
 144   shape_plan->num_user_features = num_user_features;
 145   shape_plan->user_features = features;
 146   if (num_user_features)
 147     memcpy (features, user_features, num_user_features * sizeof (hb_feature_t));
 148
 149   hb_shape_plan_plan (shape_plan, user_features, num_user_features, shaper_list);
 150
 151   return shape_plan;
 152 }
 153
 154 /**
 155  * hb_shape_plan_get_empty:
 156  *
 157  *
 158  *
 159  * Return value: (transfer full):
 160  *
 161  * Since: 1.0
 162  **/
 163 hb_shape_plan_t *
 164 hb_shape_plan_get_empty (void)
 165 {
 166   static const hb_shape_plan_t _hb_shape_plan_nil = {
 167     HB_OBJECT_HEADER_STATIC,
 168
 169     true, /* default_shaper_list */
 170     NULL, /* face */
 171     HB_SEGMENT_PROPERTIES_DEFAULT, /* props */
 172
 173     NULL, /* shaper_func */
 174     NULL, /* shaper_name */
 175
 176     NULL, /* user_features */
 177     0,    /* num_user_featurs */
 178
 179     {
 180 #define HB_SHAPER_IMPLEMENT(shaper) HB_SHAPER_DATA_INVALID,
 181 #include "hb-shaper-list.hh"
 182 #undef HB_SHAPER_IMPLEMENT
 183     }
 184   };
 185
 186   return const_cast<hb_shape_plan_t *> (&_hb_shape_plan_nil);
 187 }
 188
 189 /**
 190  * hb_shape_plan_reference: (skip)
 191  * @shape_plan: a shape plan.
 192  *
 193  *
 194  *
 195  * Return value: (transfer full):
 196  *
 197  * Since: 1.0
 198  **/
 199 hb_shape_plan_t *
 200 hb_shape_plan_reference (hb_shape_plan_t *shape_plan)
 201 {
 202   return hb_object_reference (shape_plan);
 203 }
 204
 205 /**
 206  * hb_shape_plan_destroy: (skip)
 207  * @shape_plan: a shape plan.
 208  *
 209  *
 210  *
 211  * Since: 1.0
 212  **/
 213 void
 214 hb_shape_plan_destroy (hb_shape_plan_t *shape_plan)
 215 {
 216   if (!hb_object_destroy (shape_plan)) return;
 217
 218 #define HB_SHAPER_IMPLEMENT(shaper) HB_SHAPER_DATA_DESTROY(shaper, shape_plan);
 219 #include "hb-shaper-list.hh"
 220 #undef HB_SHAPER_IMPLEMENT
 221
 222   free (shape_plan->user_features);
 223
 224   free (shape_plan);
 225 }
 226
 227 /**
 228  * hb_shape_plan_set_user_data: (skip)
 229  * @shape_plan: a shape plan.
 230  * @key:
 231  * @data:
 232  * @destroy:
 233  * @replace:
 234  *
 235  *
 236  *
 237  * Return value:
 238  *
 239  * Since: 1.0
 240  **/
 241 hb_bool_t
 242 hb_shape_plan_set_user_data (hb_shape_plan_t    *shape_plan,
 243                              hb_user_data_key_t *key,
 244                              void *              data,
 245                              hb_destroy_func_t   destroy,
 246                              hb_bool_t           replace)
 247 {
 248   return hb_object_set_user_data (shape_plan, key, data, destroy, replace);
 249 }
 250
 251 /**
 252  * hb_shape_plan_get_user_data: (skip)
 253  * @shape_plan: a shape plan.
 254  * @key:
 255  *
 256  *
 257  *
 258  * Return value: (transfer none):
 259  *
 260  * Since: 1.0
 261  **/
 262 void *
 263 hb_shape_plan_get_user_data (hb_shape_plan_t    *shape_plan,
 264                              hb_user_data_key_t *key)
 265 {
 266   return hb_object_get_user_data (shape_plan, key);
 267 }
 268
 269
 270 /**
 271  * hb_shape_plan_execute:
 272  * @shape_plan: a shape plan.
 273  * @font: a font.
 274  * @buffer: a buffer.
 275  * @features: (array length=num_features):
 276  * @num_features:
 277  *
 278  *
 279  *
 280  * Return value:
 281  *
 282  * Since: 1.0
 283  **/
 284 hb_bool_t
 285 hb_shape_plan_execute (hb_shape_plan_t    *shape_plan,
 286                        hb_font_t          *font,
 287                        hb_buffer_t        *buffer,
 288                        const hb_feature_t *features,
 289                        unsigned int        num_features)
 290 {
 291   DEBUG_MSG_FUNC (SHAPE_PLAN, shape_plan,
 292                   "num_features=%d shaper_func=%p",
 293                   num_features,
 294                   shape_plan->shaper_func);
 295
 296   if (unlikely (hb_object_is_inert (shape_plan) ||
 297                 hb_object_is_inert (font) ||
 298                 hb_object_is_inert (buffer)))
 299     return false;
 300
 301   assert (shape_plan->face_unsafe == font->face);
 302   assert (hb_segment_properties_equal (&shape_plan->props, &buffer->props));
 303
 304 #define HB_SHAPER_EXECUTE(shaper) \
 305         HB_STMT_START { \
 306           return HB_SHAPER_DATA (shaper, shape_plan) && \
 307                  hb_##shaper##_shaper_font_data_ensure (font) && \
 308                  _hb_##shaper##_shape (shape_plan, font, buffer, features, num_features); \
 309         } HB_STMT_END
 310
 311   if (0)
 312     ;
 313 #define HB_SHAPER_IMPLEMENT(shaper) \
 314   else if (shape_plan->shaper_func == _hb_##shaper##_shape) \
 315     HB_SHAPER_EXECUTE (shaper);
 316 #include "hb-shaper-list.hh"
 317 #undef HB_SHAPER_IMPLEMENT
 318
 319 #undef HB_SHAPER_EXECUTE
 320
 321   return false;
 322 }
 323
 324
 325 /*
 326  * caching
 327  */
 328
 329 #if 0
 330 static unsigned int
 331 hb_shape_plan_hash (const hb_shape_plan_t *shape_plan)
 332 {
 333   return hb_segment_properties_hash (&shape_plan->props) +
 334          shape_plan->default_shaper_list ? 0 : (intptr_t) shape_plan->shaper_func;
 335 }
 336 #endif
 337
 338 /* User-feature caching is currently somewhat dumb:
 339  * it only finds matches where the feature array is identical,
 340  * not cases where the feature lists would be compatible for plan purposes
 341  * but have different ranges, for example.
 342  */
 343 struct hb_shape_plan_proposal_t
 344 {
 345   const hb_segment_properties_t  props;
 346   const char * const            *shaper_list;
 347   const hb_feature_t            *user_features;
 348   unsigned int                   num_user_features;
 349   hb_shape_func_t               *shaper_func;
 350 };
 351
 352 static inline hb_bool_t
 353 hb_shape_plan_user_features_match (const hb_shape_plan_t          *shape_plan,
 354                                    const hb_shape_plan_proposal_t *proposal)
 355 {
 356   if (proposal->num_user_features != shape_plan->num_user_features) return false;
 357   for (unsigned int i = 0, n = proposal->num_user_features; i < n; i++)
 358     if (proposal->user_features[i].tag   != shape_plan->user_features[i].tag   ||
 359         proposal->user_features[i].value != shape_plan->user_features[i].value ||
 360         proposal->user_features[i].start != shape_plan->user_features[i].start ||
 361         proposal->user_features[i].end   != shape_plan->user_features[i].end) return false;
 362   return true;
 363 }
 364
 365 static hb_bool_t
 366 hb_shape_plan_matches (const hb_shape_plan_t          *shape_plan,
 367                        const hb_shape_plan_proposal_t *proposal)
 368 {
 369   return hb_segment_properties_equal (&shape_plan->props, &proposal->props) &&
 370          hb_shape_plan_user_features_match (shape_plan, proposal) &&
 371          ((shape_plan->default_shaper_list && proposal->shaper_list == NULL) ||
 372           (shape_plan->shaper_func == proposal->shaper_func));
 373 }
 374
 375 static inline hb_bool_t
 376 hb_non_global_user_features_present (const hb_feature_t *user_features,
 377                                      unsigned int        num_user_features)
 378 {
 379   while (num_user_features)
 380     if (user_features->start != 0 || user_features->end != (unsigned int) -1)
 381       return true;
 382     else
 383       num_user_features--, user_features++;
 384   return false;
 385 }
 386
 387 /**
 388  * hb_shape_plan_create_cached:
 389  * @face:
 390  * @props:
 391  * @user_features: (array length=num_user_features):
 392  * @num_user_features:
 393  * @shaper_list: (array zero-terminated=1):
 394  *
 395  *
 396  *
 397  * Return value: (transfer full):
 398  *
 399  * Since: 1.0
 400  **/
 401 hb_shape_plan_t *
 402 hb_shape_plan_create_cached (hb_face_t                     *face,
 403                              const hb_segment_properties_t *props,
 404                              const hb_feature_t            *user_features,
 405                              unsigned int                   num_user_features,
 406                              const char * const            *shaper_list)
 407 {
 408   DEBUG_MSG_FUNC (SHAPE_PLAN, NULL,
 409                   "face=%p num_features=%d shaper_list=%p",
 410                   face,
 411                   num_user_features,
 412                   shaper_list);
 413
 414   hb_shape_plan_proposal_t proposal = {
 415     *props,
 416     shaper_list,
 417     user_features,
 418     num_user_features,
 419     NULL
 420   };
 421
 422   if (shaper_list) {
 423     /* Choose shaper.  Adapted from hb_shape_plan_plan().
 424      * Must choose shaper exactly the same way as that function. */
 425     for (const char * const *shaper_item = shaper_list; *shaper_item; shaper_item++)
 426       if (0)
 427         ;
 428 #define HB_SHAPER_IMPLEMENT(shaper) \
 429       else if (0 == strcmp (*shaper_item, #shaper) && \
 430                hb_##shaper##_shaper_face_data_ensure (face)) \
 431       { \
 432         proposal.shaper_func = _hb_##shaper##_shape; \
 433         break; \
 434       }
 435 #include "hb-shaper-list.hh"
 436 #undef HB_SHAPER_IMPLEMENT
 437
 438     if (unlikely (!proposal.shaper_func))
 439       return hb_shape_plan_get_empty ();
 440   }
 441
 442
 443 retry:
 444   hb_face_t::plan_node_t *cached_plan_nodes = (hb_face_t::plan_node_t *) hb_atomic_ptr_get (&face->shape_plans);
 445   for (hb_face_t::plan_node_t *node = cached_plan_nodes; node; node = node->next)
 446     if (hb_shape_plan_matches (node->shape_plan, &proposal))
 447     {
 448       DEBUG_MSG_FUNC (SHAPE_PLAN, node->shape_plan, "fulfilled from cache");
 449       return hb_shape_plan_reference (node->shape_plan);
 450     }
 451
 452   /* Not found. */
 453
 454   hb_shape_plan_t *shape_plan = hb_shape_plan_create (face, props, user_features, num_user_features, shaper_list);
 455
 456   /* Don't add the plan to the cache if there were user features with non-global ranges */
 457
 458   if (hb_non_global_user_features_present (user_features, num_user_features))
 459     return shape_plan;
 460
 461   hb_face_t::plan_node_t *node = (hb_face_t::plan_node_t *) calloc (1, sizeof (hb_face_t::plan_node_t));
 462   if (unlikely (!node))
 463     return shape_plan;
 464
 465   node->shape_plan = shape_plan;
 466   node->next = cached_plan_nodes;
 467
 468   if (!hb_atomic_ptr_cmpexch (&face->shape_plans, cached_plan_nodes, node)) {
 469     hb_shape_plan_destroy (shape_plan);
 470     free (node);
 471     goto retry;
 472   }
 473   DEBUG_MSG_FUNC (SHAPE_PLAN, shape_plan, "inserted into cache");
 474
 475   return hb_shape_plan_reference (shape_plan);
 476 }
 477
 478 /**
 479  * hb_shape_plan_get_shaper:
 480  * @shape_plan: a shape plan.
 481  *
 482  *
 483  *
 484  * Return value: (transfer none):
 485  *
 486  * Since: 1.0
 487  **/
 488 const char *
 489 hb_shape_plan_get_shaper (hb_shape_plan_t *shape_plan)
 490 {
 491   return shape_plan->shaper_name;
 492 }