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
  31 #define HB_SHAPER_IMPLEMENT(shaper) \
  32         HB_SHAPER_DATA_ENSURE_DECLARE(shaper, face) \
  33         HB_SHAPER_DATA_ENSURE_DECLARE(shaper, font)
  34 #include "hb-shaper-list.hh"
  35 #undef HB_SHAPER_IMPLEMENT
  36
  37
  38 static void
  39 hb_shape_plan_plan (hb_shape_plan_t    *shape_plan,
  40                     const hb_feature_t *user_features,
  41                     unsigned int        num_user_features,
  42                     const char * const *shaper_list)
  43 {
  44   const hb_shaper_pair_t *shapers = _hb_shapers_get ();
  45
  46 #define HB_SHAPER_PLAN(shaper) \
  47         HB_STMT_START { \
  48           if (hb_##shaper##_shaper_face_data_ensure (shape_plan->face)) { \
  49             HB_SHAPER_DATA (shaper, shape_plan) = \
  50               HB_SHAPER_DATA_CREATE_FUNC (shaper, shape_plan) (shape_plan, user_features, num_user_features); \
  51             shape_plan->shaper_func = _hb_##shaper##_shape; \
  52             shape_plan->shaper_name = #shaper; \
  53             return; \
  54           } \
  55         } HB_STMT_END
  56
  57   if (likely (!shaper_list)) {
  58     for (unsigned int i = 0; i < HB_SHAPERS_COUNT; i++)
  59       if (0)
  60         ;
  61 #define HB_SHAPER_IMPLEMENT(shaper) \
  62       else if (shapers[i].func == _hb_##shaper##_shape) \
  63         HB_SHAPER_PLAN (shaper);
  64 #include "hb-shaper-list.hh"
  65 #undef HB_SHAPER_IMPLEMENT
  66   } else {
  67     for (; *shaper_list; shaper_list++)
  68       if (0)
  69         ;
  70 #define HB_SHAPER_IMPLEMENT(shaper) \
  71       else if (0 == strcmp (*shaper_list, #shaper)) \
  72         HB_SHAPER_PLAN (shaper);
  73 #include "hb-shaper-list.hh"
  74 #undef HB_SHAPER_IMPLEMENT
  75   }
  76
  77 #undef HB_SHAPER_PLAN
  78 }
  79
  80
  81 /*
  82  * hb_shape_plan_t
  83  */
  84
  85 hb_shape_plan_t *
  86 hb_shape_plan_create (hb_face_t                     *face,
  87                       const hb_segment_properties_t *props,
  88                       const hb_feature_t            *user_features,
  89                       unsigned int                   num_user_features,
  90                       const char * const            *shaper_list)
  91 {
  92   assert (props->direction != HB_DIRECTION_INVALID);
  93
  94   hb_shape_plan_t *shape_plan;
  95
  96   if (unlikely (!face))
  97     face = hb_face_get_empty ();
  98   if (unlikely (!props || hb_object_is_inert (face)))
  99     return hb_shape_plan_get_empty ();
 100   if (!(shape_plan = hb_object_create<hb_shape_plan_t> ()))
 101     return hb_shape_plan_get_empty ();
 102
 103   hb_face_make_immutable (face);
 104   shape_plan->default_shaper_list = shaper_list == NULL;
 105   shape_plan->face = hb_face_reference (face);
 106   shape_plan->props = *props;
 107
 108   hb_shape_plan_plan (shape_plan, user_features, num_user_features, shaper_list);
 109
 110   return shape_plan;
 111 }
 112
 113 hb_shape_plan_t *
 114 hb_shape_plan_get_empty (void)
 115 {
 116   static const hb_shape_plan_t _hb_shape_plan_nil = {
 117     HB_OBJECT_HEADER_STATIC,
 118
 119     true, /* default_shaper_list */
 120     NULL, /* face */
 121     HB_SEGMENT_PROPERTIES_DEFAULT, /* props */
 122
 123     NULL, /* shaper_func */
 124     NULL, /* shaper_name */
 125
 126     {
 127 #define HB_SHAPER_IMPLEMENT(shaper) HB_SHAPER_DATA_INVALID,
 128 #include "hb-shaper-list.hh"
 129 #undef HB_SHAPER_IMPLEMENT
 130     }
 131   };
 132
 133   return const_cast<hb_shape_plan_t *> (&_hb_shape_plan_nil);
 134 }
 135
 136 hb_shape_plan_t *
 137 hb_shape_plan_reference (hb_shape_plan_t *shape_plan)
 138 {
 139   return hb_object_reference (shape_plan);
 140 }
 141
 142 void
 143 hb_shape_plan_destroy (hb_shape_plan_t *shape_plan)
 144 {
 145   if (!hb_object_destroy (shape_plan)) return;
 146
 147 #define HB_SHAPER_IMPLEMENT(shaper) HB_SHAPER_DATA_DESTROY(shaper, shape_plan);
 148 #include "hb-shaper-list.hh"
 149 #undef HB_SHAPER_IMPLEMENT
 150
 151   hb_face_destroy (shape_plan->face);
 152
 153   free (shape_plan);
 154 }
 155
 156 hb_bool_t
 157 hb_shape_plan_set_user_data (hb_shape_plan_t    *shape_plan,
 158                              hb_user_data_key_t *key,
 159                              void *              data,
 160                              hb_destroy_func_t   destroy,
 161                              hb_bool_t           replace)
 162 {
 163   return hb_object_set_user_data (shape_plan, key, data, destroy, replace);
 164 }
 165
 166 void *
 167 hb_shape_plan_get_user_data (hb_shape_plan_t    *shape_plan,
 168                              hb_user_data_key_t *key)
 169 {
 170   return hb_object_get_user_data (shape_plan, key);
 171 }
 172
 173
 174 hb_bool_t
 175 hb_shape_plan_execute (hb_shape_plan_t    *shape_plan,
 176                        hb_font_t          *font,
 177                        hb_buffer_t        *buffer,
 178                        const hb_feature_t *features,
 179                        unsigned int        num_features)
 180 {
 181   if (unlikely (shape_plan->face != font->face))
 182     return false;
 183
 184 #define HB_SHAPER_EXECUTE(shaper) \
 185         HB_STMT_START { \
 186           return HB_SHAPER_DATA (shaper, shape_plan) && \
 187                  hb_##shaper##_shaper_font_data_ensure (font) && \
 188                  _hb_##shaper##_shape (shape_plan, font, buffer, features, num_features); \
 189         } HB_STMT_END
 190
 191   if (0)
 192     ;
 193 #define HB_SHAPER_IMPLEMENT(shaper) \
 194   else if (shape_plan->shaper_func == _hb_##shaper##_shape) \
 195     HB_SHAPER_EXECUTE (shaper);
 196 #include "hb-shaper-list.hh"
 197 #undef HB_SHAPER_IMPLEMENT
 198
 199 #undef HB_SHAPER_EXECUTE
 200
 201   return false;
 202 }
 203
 204
 205 /*
 206  * caching
 207  */
 208
 209 #if 0
 210 static unsigned int
 211 hb_shape_plan_hash (const hb_shape_plan_t *shape_plan)
 212 {
 213   return hb_segment_properties_hash (&shape_plan->props) +
 214          shape_plan->default_shaper_list ? 0 : (intptr_t) shape_plan->shaper_func;
 215 }
 216 #endif
 217
 218 /* TODO no user-feature caching for now. */
 219 struct hb_shape_plan_proposal_t
 220 {
 221   const hb_segment_properties_t  props;
 222   const char * const            *shaper_list;
 223   hb_shape_func_t               *shaper_func;
 224 };
 225
 226 static hb_bool_t
 227 hb_shape_plan_matches (const hb_shape_plan_t          *shape_plan,
 228                        const hb_shape_plan_proposal_t *proposal)
 229 {
 230   return hb_segment_properties_equal (&shape_plan->props, &proposal->props) &&
 231          ((shape_plan->default_shaper_list && proposal->shaper_list == NULL) ||
 232           (shape_plan->shaper_func == proposal->shaper_func));
 233 }
 234
 235 hb_shape_plan_t *
 236 hb_shape_plan_create_cached (hb_face_t                     *face,
 237                              const hb_segment_properties_t *props,
 238                              const hb_feature_t            *user_features,
 239                              unsigned int                   num_user_features,
 240                              const char * const            *shaper_list)
 241 {
 242   if (num_user_features)
 243     return hb_shape_plan_create (face, props, user_features, num_user_features, shaper_list);
 244
 245   hb_shape_plan_proposal_t proposal = {
 246     *props,
 247     shaper_list,
 248     NULL
 249   };
 250
 251   if (shaper_list) {
 252     /* Choose shaper.  Adapted from hb_shape_plan_plan(). */
 253 #define HB_SHAPER_PLAN(shaper) \
 254           HB_STMT_START { \
 255             if (hb_##shaper##_shaper_face_data_ensure (face)) \
 256               proposal.shaper_func = _hb_##shaper##_shape; \
 257           } HB_STMT_END
 258
 259     for (const char * const *shaper_item = shaper_list; *shaper_item; shaper_item++)
 260       if (0)
 261         ;
 262 #define HB_SHAPER_IMPLEMENT(shaper) \
 263       else if (0 == strcmp (*shaper_item, #shaper)) \
 264         HB_SHAPER_PLAN (shaper);
 265 #include "hb-shaper-list.hh"
 266 #undef HB_SHAPER_IMPLEMENT
 267
 268 #undef HB_SHAPER_PLAN
 269
 270     if (unlikely (!proposal.shaper_list))
 271       return hb_shape_plan_get_empty ();
 272   }
 273
 274
 275 retry:
 276   hb_face_t::plan_node_t *cached_plan_nodes = (hb_face_t::plan_node_t *) hb_atomic_ptr_get (&face->shape_plans);
 277   for (hb_face_t::plan_node_t *node = cached_plan_nodes; node; node = node->next)
 278     if (hb_shape_plan_matches (node->shape_plan, &proposal))
 279       return hb_shape_plan_reference (node->shape_plan);
 280
 281   /* Not found. */
 282
 283   hb_shape_plan_t *shape_plan = hb_shape_plan_create (face, props, user_features, num_user_features, shaper_list);
 284
 285   hb_face_t::plan_node_t *node = (hb_face_t::plan_node_t *) calloc (1, sizeof (hb_face_t::plan_node_t));
 286   if (unlikely (!node))
 287     return shape_plan;
 288
 289   node->shape_plan = shape_plan;
 290   node->next = cached_plan_nodes;
 291
 292   if (!hb_atomic_ptr_cmpexch (&face->shape_plans, cached_plan_nodes, node)) {
 293     hb_shape_plan_destroy (shape_plan);
 294     free (node);
 295     goto retry;
 296   }
 297
 298   /* Release our reference on face. */
 299   hb_face_destroy (face);
 300
 301   return hb_shape_plan_reference (shape_plan);
 302 }
 303
 304 const char *
 305 hb_shape_plan_get_shaper (hb_shape_plan_t *shape_plan)
 306 {
 307   return shape_plan->shaper_name;
 308 }