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-private.hh"
  28
  29 #include "hb-shape-plan-private.hh"
  30 #include "hb-shaper-private.hh"
  31 #include "hb-font-private.hh"
  32
  33 #define HB_SHAPER_IMPLEMENT(shaper) \
  34         HB_SHAPER_DATA_ENSURE_DECLARE(shaper, face) \
  35         HB_SHAPER_DATA_ENSURE_DECLARE(shaper, font)
  36 #include "hb-shaper-list.hh"
  37 #undef HB_SHAPER_IMPLEMENT
  38
  39
  40 static void
  41 hb_shape_plan_plan (hb_shape_plan_t    *shape_plan,
  42                     const hb_feature_t *user_features,
  43                     unsigned int        num_user_features,
  44                     const char * const *shaper_list)
  45 {
  46   const hb_shaper_pair_t *shapers = _hb_shapers_get ();
  47
  48 #define HB_SHAPER_PLAN(shaper) \
  49         HB_STMT_START { \
  50           if (hb_##shaper##_shaper_face_data_ensure (shape_plan->face)) { \
  51             HB_SHAPER_DATA (shaper, shape_plan) = \
  52               HB_SHAPER_DATA_CREATE_FUNC (shaper, shape_plan) (shape_plan, user_features, num_user_features); \
  53             shape_plan->shaper_func = _hb_##shaper##_shape; \
  54             return; \
  55           } \
  56         } HB_STMT_END
  57
  58   if (likely (!shaper_list)) {
  59     for (unsigned int i = 0; i < HB_SHAPERS_COUNT; i++)
  60       if (0)
  61         ;
  62 #define HB_SHAPER_IMPLEMENT(shaper) \
  63       else if (shapers[i].func == _hb_##shaper##_shape) \
  64         HB_SHAPER_PLAN (shaper);
  65 #include "hb-shaper-list.hh"
  66 #undef HB_SHAPER_IMPLEMENT
  67   } else {
  68     for (; *shaper_list; shaper_list++)
  69       if (0)
  70         ;
  71 #define HB_SHAPER_IMPLEMENT(shaper) \
  72       else if (0 == strcmp (*shaper_list, #shaper)) \
  73         HB_SHAPER_PLAN (shaper);
  74 #include "hb-shaper-list.hh"
  75 #undef HB_SHAPER_IMPLEMENT
  76   }
  77
  78 #undef HB_SHAPER_PLAN
  79 }
  80
  81
  82 /*
  83  * hb_shape_plan_t
  84  */
  85
  86 hb_shape_plan_t *
  87 hb_shape_plan_create (hb_face_t                     *face,
  88                       const hb_segment_properties_t *props,
  89                       const hb_feature_t            *user_features,
  90                       unsigned int                   num_user_features,
  91                       const char * const            *shaper_list)
  92 {
  93   assert (props->direction != HB_DIRECTION_INVALID);
  94
  95   hb_shape_plan_t *shape_plan;
  96
  97   if (unlikely (!face))
  98     face = hb_face_get_empty ();
  99   if (unlikely (!props || hb_object_is_inert (face)))
 100     return hb_shape_plan_get_empty ();
 101   if (!(shape_plan = hb_object_create<hb_shape_plan_t> ()))
 102     return hb_shape_plan_get_empty ();
 103
 104   hb_face_make_immutable (face);
 105   shape_plan->default_shaper_list = shaper_list == NULL;
 106   shape_plan->face = hb_face_reference (face);
 107   shape_plan->props = *props;
 108
 109   hb_shape_plan_plan (shape_plan, user_features, num_user_features, shaper_list);
 110
 111   return shape_plan;
 112 }
 113
 114 hb_shape_plan_t *
 115 hb_shape_plan_get_empty (void)
 116 {
 117   static const hb_shape_plan_t _hb_shape_plan_nil = {
 118     HB_OBJECT_HEADER_STATIC,
 119
 120     true, /* default_shaper_list */
 121     NULL, /* face */
 122     _HB_BUFFER_PROPS_DEFAULT, /* props */
 123
 124     NULL, /* shaper_func */
 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
 157 hb_bool_t
 158 hb_shape_plan_execute (hb_shape_plan      *shape_plan,
 159                        hb_font_t          *font,
 160                        hb_buffer_t        *buffer,
 161                        const hb_feature_t *features,
 162                        unsigned int        num_features)
 163 {
 164   if (unlikely (shape_plan->face != font->face))
 165     return false;
 166
 167 #define HB_SHAPER_EXECUTE(shaper) \
 168         HB_STMT_START { \
 169           return HB_SHAPER_DATA (shaper, shape_plan) && \
 170                  hb_##shaper##_shaper_font_data_ensure (font) && \
 171                  _hb_##shaper##_shape (shape_plan, font, buffer, features, num_features); \
 172         } HB_STMT_END
 173
 174   if (0)
 175     ;
 176 #define HB_SHAPER_IMPLEMENT(shaper) \
 177   else if (shape_plan->shaper_func == _hb_##shaper##_shape) \
 178     HB_SHAPER_EXECUTE (shaper);
 179 #include "hb-shaper-list.hh"
 180 #undef HB_SHAPER_IMPLEMENT
 181
 182 #undef HB_SHAPER_EXECUTE
 183
 184   return false;
 185 }
 186
 187
 188 /*
 189  * caching
 190  */
 191
 192 #if 0
 193 static unsigned int
 194 hb_shape_plan_hash (const hb_shape_plan_t *shape_plan)
 195 {
 196   return hb_segment_properties_hash (&shape_plan->props) +
 197          shape_plan->default_shaper_list ? 0 : (intptr_t) shape_plan->shaper_func;
 198 }
 199 #endif
 200
 201 /* TODO no user-feature caching for now. */
 202 struct hb_shape_plan_proposal_t
 203 {
 204   const hb_segment_properties_t  props;
 205   const char * const            *shaper_list;
 206   hb_shape_func_t               *shaper_func;
 207 };
 208
 209 static hb_bool_t
 210 hb_shape_plan_matches (const hb_shape_plan_t          *shape_plan,
 211                        const hb_shape_plan_proposal_t *proposal)
 212 {
 213   return hb_segment_properties_equal (&shape_plan->props, &proposal->props) &&
 214          ((shape_plan->default_shaper_list && proposal->shaper_list == NULL) ||
 215           (shape_plan->shaper_func == proposal->shaper_func));
 216 }
 217
 218 hb_shape_plan_t *
 219 hb_shape_plan_create_cached (hb_face_t                     *face,
 220                              const hb_segment_properties_t *props,
 221                              const hb_feature_t            *user_features,
 222                              unsigned int                   num_user_features,
 223                              const char * const            *shaper_list)
 224 {
 225   if (num_user_features)
 226     return hb_shape_plan_create (face, props, user_features, num_user_features, shaper_list);
 227
 228   hb_shape_plan_proposal_t proposal = {
 229     *props,
 230     shaper_list,
 231     NULL
 232   };
 233
 234   if (shaper_list) {
 235     /* Choose shaper.  Adapted from hb_shape_plan_plan(). */
 236 #define HB_SHAPER_PLAN(shaper) \
 237           HB_STMT_START { \
 238             if (hb_##shaper##_shaper_face_data_ensure (face)) \
 239               proposal.shaper_func = _hb_##shaper##_shape; \
 240           } HB_STMT_END
 241
 242     for (const char * const *shaper_item = shaper_list; *shaper_item; shaper_item++)
 243       if (0)
 244         ;
 245 #define HB_SHAPER_IMPLEMENT(shaper) \
 246       else if (0 == strcmp (*shaper_item, #shaper)) \
 247         HB_SHAPER_PLAN (shaper);
 248 #include "hb-shaper-list.hh"
 249 #undef HB_SHAPER_IMPLEMENT
 250
 251 #undef HB_SHAPER_PLAN
 252
 253     if (unlikely (!proposal.shaper_list))
 254       return hb_shape_plan_get_empty ();
 255   }
 256
 257
 258 retry:
 259   hb_face_t::plan_node_t *cached_plan_nodes = (hb_face_t::plan_node_t *) hb_atomic_ptr_get (&face->shape_plans);
 260   for (hb_face_t::plan_node_t *node = cached_plan_nodes; node; node = node->next)
 261     if (hb_shape_plan_matches (node->shape_plan, &proposal))
 262       return hb_shape_plan_reference (node->shape_plan);
 263
 264   /* Not found. */
 265
 266   hb_shape_plan_t *shape_plan = hb_shape_plan_create (face, props, user_features, num_user_features, shaper_list);
 267
 268   hb_face_t::plan_node_t *node = (hb_face_t::plan_node_t *) calloc (1, sizeof (hb_face_t::plan_node_t));
 269   if (unlikely (!node))
 270     return shape_plan;
 271
 272   node->shape_plan = shape_plan;
 273   node->next = cached_plan_nodes;
 274
 275   if (!hb_atomic_ptr_cmpexch (&face->shape_plans, cached_plan_nodes, node)) {
 276     hb_shape_plan_destroy (shape_plan);
 277     free (node);
 278     goto retry;
 279   }
 280
 281   /* Release our reference on face. */
 282   hb_face_destroy (face);
 283
 284   return hb_shape_plan_reference (shape_plan);
 285 }