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
hb_shape_plan_plan(hb_shape_plan_t * shape_plan,const hb_feature_t * user_features,unsigned int num_user_features,const char * const * shaper_list)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: 0.9.7
110  **/
111 hb_shape_plan_t *
hb_shape_plan_create(hb_face_t * face,const hb_segment_properties_t * props,const hb_feature_t * user_features,unsigned int num_user_features,const char * const * shaper_list)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))
130     return hb_shape_plan_get_empty ();
131   if (num_user_features && !(features = (hb_feature_t *) calloc (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: 0.9.7
162  **/
163 hb_shape_plan_t *
hb_shape_plan_get_empty(void)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: 0.9.7
198  **/
199 hb_shape_plan_t *
hb_shape_plan_reference(hb_shape_plan_t * shape_plan)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: 0.9.7
212  **/
213 void
hb_shape_plan_destroy(hb_shape_plan_t * shape_plan)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: 0.9.7
240  **/
241 hb_bool_t
hb_shape_plan_set_user_data(hb_shape_plan_t * shape_plan,hb_user_data_key_t * key,void * data,hb_destroy_func_t destroy,hb_bool_t replace)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: 0.9.7
261  **/
262 void *
hb_shape_plan_get_user_data(hb_shape_plan_t * shape_plan,hb_user_data_key_t * key)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: 0.9.7
283  **/
284 hb_bool_t
hb_shape_plan_execute(hb_shape_plan_t * shape_plan,hb_font_t * font,hb_buffer_t * buffer,const hb_feature_t * features,unsigned int num_features)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 (!buffer->len))
297     return true;
298 
299   assert (!hb_object_is_inert (buffer));
300   assert (buffer->content_type == HB_BUFFER_CONTENT_TYPE_UNICODE);
301 
302   if (unlikely (hb_object_is_inert (shape_plan)))
303     return false;
304 
305   assert (shape_plan->face_unsafe == font->face);
306   assert (hb_segment_properties_equal (&shape_plan->props, &buffer->props));
307 
308 #define HB_SHAPER_EXECUTE(shaper) \
309 	HB_STMT_START { \
310 	  return HB_SHAPER_DATA (shaper, shape_plan) && \
311 		 hb_##shaper##_shaper_font_data_ensure (font) && \
312 		 _hb_##shaper##_shape (shape_plan, font, buffer, features, num_features); \
313 	} HB_STMT_END
314 
315   if (0)
316     ;
317 #define HB_SHAPER_IMPLEMENT(shaper) \
318   else if (shape_plan->shaper_func == _hb_##shaper##_shape) \
319     HB_SHAPER_EXECUTE (shaper);
320 #include "hb-shaper-list.hh"
321 #undef HB_SHAPER_IMPLEMENT
322 
323 #undef HB_SHAPER_EXECUTE
324 
325   return false;
326 }
327 
328 
329 /*
330  * caching
331  */
332 
333 #if 0
334 static unsigned int
335 hb_shape_plan_hash (const hb_shape_plan_t *shape_plan)
336 {
337   return hb_segment_properties_hash (&shape_plan->props) +
338 	 shape_plan->default_shaper_list ? 0 : (intptr_t) shape_plan->shaper_func;
339 }
340 #endif
341 
342 /* User-feature caching is currently somewhat dumb:
343  * it only finds matches where the feature array is identical,
344  * not cases where the feature lists would be compatible for plan purposes
345  * but have different ranges, for example.
346  */
347 struct hb_shape_plan_proposal_t
348 {
349   const hb_segment_properties_t  props;
350   const char * const            *shaper_list;
351   const hb_feature_t            *user_features;
352   unsigned int                   num_user_features;
353   hb_shape_func_t               *shaper_func;
354 };
355 
356 static inline hb_bool_t
hb_shape_plan_user_features_match(const hb_shape_plan_t * shape_plan,const hb_shape_plan_proposal_t * proposal)357 hb_shape_plan_user_features_match (const hb_shape_plan_t          *shape_plan,
358 				   const hb_shape_plan_proposal_t *proposal)
359 {
360   if (proposal->num_user_features != shape_plan->num_user_features) return false;
361   for (unsigned int i = 0, n = proposal->num_user_features; i < n; i++)
362     if (proposal->user_features[i].tag   != shape_plan->user_features[i].tag   ||
363         proposal->user_features[i].value != shape_plan->user_features[i].value ||
364         proposal->user_features[i].start != shape_plan->user_features[i].start ||
365         proposal->user_features[i].end   != shape_plan->user_features[i].end) return false;
366   return true;
367 }
368 
369 static hb_bool_t
hb_shape_plan_matches(const hb_shape_plan_t * shape_plan,const hb_shape_plan_proposal_t * proposal)370 hb_shape_plan_matches (const hb_shape_plan_t          *shape_plan,
371 		       const hb_shape_plan_proposal_t *proposal)
372 {
373   return hb_segment_properties_equal (&shape_plan->props, &proposal->props) &&
374 	 hb_shape_plan_user_features_match (shape_plan, proposal) &&
375 	 ((shape_plan->default_shaper_list && proposal->shaper_list == NULL) ||
376 	  (shape_plan->shaper_func == proposal->shaper_func));
377 }
378 
379 static inline hb_bool_t
hb_non_global_user_features_present(const hb_feature_t * user_features,unsigned int num_user_features)380 hb_non_global_user_features_present (const hb_feature_t *user_features,
381 				     unsigned int        num_user_features)
382 {
383   while (num_user_features)
384     if (user_features->start != 0 || user_features->end != (unsigned int) -1)
385       return true;
386     else
387       num_user_features--, user_features++;
388   return false;
389 }
390 
391 /**
392  * hb_shape_plan_create_cached:
393  * @face:
394  * @props:
395  * @user_features: (array length=num_user_features):
396  * @num_user_features:
397  * @shaper_list: (array zero-terminated=1):
398  *
399  *
400  *
401  * Return value: (transfer full):
402  *
403  * Since: 0.9.7
404  **/
405 hb_shape_plan_t *
hb_shape_plan_create_cached(hb_face_t * face,const hb_segment_properties_t * props,const hb_feature_t * user_features,unsigned int num_user_features,const char * const * shaper_list)406 hb_shape_plan_create_cached (hb_face_t                     *face,
407 			     const hb_segment_properties_t *props,
408 			     const hb_feature_t            *user_features,
409 			     unsigned int                   num_user_features,
410 			     const char * const            *shaper_list)
411 {
412   DEBUG_MSG_FUNC (SHAPE_PLAN, NULL,
413 		  "face=%p num_features=%d shaper_list=%p",
414 		  face,
415 		  num_user_features,
416 		  shaper_list);
417 
418   hb_shape_plan_proposal_t proposal = {
419     *props,
420     shaper_list,
421     user_features,
422     num_user_features,
423     NULL
424   };
425 
426   if (shaper_list) {
427     /* Choose shaper.  Adapted from hb_shape_plan_plan().
428      * Must choose shaper exactly the same way as that function. */
429     for (const char * const *shaper_item = shaper_list; *shaper_item; shaper_item++)
430       if (0)
431 	;
432 #define HB_SHAPER_IMPLEMENT(shaper) \
433       else if (0 == strcmp (*shaper_item, #shaper) && \
434 	       hb_##shaper##_shaper_face_data_ensure (face)) \
435       { \
436 	proposal.shaper_func = _hb_##shaper##_shape; \
437 	break; \
438       }
439 #include "hb-shaper-list.hh"
440 #undef HB_SHAPER_IMPLEMENT
441 
442     if (unlikely (!proposal.shaper_func))
443       return hb_shape_plan_get_empty ();
444   }
445 
446 
447 retry:
448   hb_face_t::plan_node_t *cached_plan_nodes = (hb_face_t::plan_node_t *) hb_atomic_ptr_get (&face->shape_plans);
449   for (hb_face_t::plan_node_t *node = cached_plan_nodes; node; node = node->next)
450     if (hb_shape_plan_matches (node->shape_plan, &proposal))
451     {
452       DEBUG_MSG_FUNC (SHAPE_PLAN, node->shape_plan, "fulfilled from cache");
453       return hb_shape_plan_reference (node->shape_plan);
454     }
455 
456   /* Not found. */
457 
458   hb_shape_plan_t *shape_plan = hb_shape_plan_create (face, props, user_features, num_user_features, shaper_list);
459 
460   /* Don't add to the cache if face is inert. */
461   if (unlikely (hb_object_is_inert (face)))
462     return shape_plan;
463 
464   /* Don't add the plan to the cache if there were user features with non-global ranges */
465 
466   if (hb_non_global_user_features_present (user_features, num_user_features))
467     return shape_plan;
468 
469   hb_face_t::plan_node_t *node = (hb_face_t::plan_node_t *) calloc (1, sizeof (hb_face_t::plan_node_t));
470   if (unlikely (!node))
471     return shape_plan;
472 
473   node->shape_plan = shape_plan;
474   node->next = cached_plan_nodes;
475 
476   if (!hb_atomic_ptr_cmpexch (&face->shape_plans, cached_plan_nodes, node)) {
477     hb_shape_plan_destroy (shape_plan);
478     free (node);
479     goto retry;
480   }
481   DEBUG_MSG_FUNC (SHAPE_PLAN, shape_plan, "inserted into cache");
482 
483   return hb_shape_plan_reference (shape_plan);
484 }
485 
486 /**
487  * hb_shape_plan_get_shaper:
488  * @shape_plan: a shape plan.
489  *
490  *
491  *
492  * Return value: (transfer none):
493  *
494  * Since: 0.9.7
495  **/
496 const char *
hb_shape_plan_get_shaper(hb_shape_plan_t * shape_plan)497 hb_shape_plan_get_shaper (hb_shape_plan_t *shape_plan)
498 {
499   return shape_plan->shaper_name;
500 }
501