src/hb-shaper-private.hh

   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 #ifndef HB_SHAPER_PRIVATE_HH
  28 #define HB_SHAPER_PRIVATE_HH
  29
  30 #include "hb-private.hh"
  31
  32 typedef hb_bool_t hb_shape_func_t (hb_shape_plan_t    *shape_plan,
  33                                    hb_font_t          *font,
  34                                    hb_buffer_t        *buffer,
  35                                    const hb_feature_t *features,
  36                                    unsigned int        num_features);
  37
  38 #define HB_SHAPER_IMPLEMENT(name) \
  39         extern "C" HB_INTERNAL hb_shape_func_t _hb_##name##_shape;
  40 #include "hb-shaper-list.hh"
  41 #undef HB_SHAPER_IMPLEMENT
  42
  43 struct hb_shaper_pair_t {
  44   char name[16];
  45   hb_shape_func_t *func;
  46 };
  47
  48 HB_INTERNAL const hb_shaper_pair_t *
  49 _hb_shapers_get (void);
  50
  51
  52 /* For embedding in face / font / ... */
  53 struct hb_shaper_data_t {
  54 #define HB_SHAPER_IMPLEMENT(shaper) void *shaper;
  55 #include "hb-shaper-list.hh"
  56 #undef HB_SHAPER_IMPLEMENT
  57 };
  58
  59 #define HB_SHAPERS_COUNT (sizeof (hb_shaper_data_t) / sizeof (void *))
  60
  61 /* Means: succeeded, but don't need to keep any data. */
  62 #define HB_SHAPER_DATA_SUCCEEDED ((void *) +1)
  63
  64 /* Means: tried but failed to create. */
  65 #define HB_SHAPER_DATA_INVALID ((void *) -1)
  66 #define HB_SHAPER_DATA_IS_INVALID(data) ((void *) (data) == HB_SHAPER_DATA_INVALID)
  67
  68 #define HB_SHAPER_DATA_TYPE_NAME(shaper, object)        hb_##shaper##_shaper_##object##_data_t
  69 #define HB_SHAPER_DATA_TYPE(shaper, object)             struct HB_SHAPER_DATA_TYPE_NAME(shaper, object)
  70 #define HB_SHAPER_DATA_INSTANCE(shaper, object, instance)       (* (HB_SHAPER_DATA_TYPE(shaper, object) **) &(instance)->shaper_data.shaper)
  71 #define HB_SHAPER_DATA(shaper, object)                  HB_SHAPER_DATA_INSTANCE(shaper, object, object)
  72 #define HB_SHAPER_DATA_CREATE_FUNC(shaper, object)      _hb_##shaper##_shaper_##object##_data_create
  73 #define HB_SHAPER_DATA_DESTROY_FUNC(shaper, object)     _hb_##shaper##_shaper_##object##_data_destroy
  74 #define HB_SHAPER_DATA_ENSURE_FUNC(shaper, object)      hb_##shaper##_shaper_##object##_data_ensure
  75
  76 #define HB_SHAPER_DATA_PROTOTYPE(shaper, object) \
  77         HB_SHAPER_DATA_TYPE (shaper, object); /* Type forward declaration. */ \
  78         extern "C" HB_INTERNAL HB_SHAPER_DATA_TYPE (shaper, object) * \
  79         HB_SHAPER_DATA_CREATE_FUNC (shaper, object) (hb_##object##_t *object HB_SHAPER_DATA_CREATE_FUNC_EXTRA_ARGS); \
  80         extern "C" HB_INTERNAL void \
  81         HB_SHAPER_DATA_DESTROY_FUNC (shaper, object) (HB_SHAPER_DATA_TYPE (shaper, object) *data); \
  82         extern "C" HB_INTERNAL bool \
  83         HB_SHAPER_DATA_ENSURE_FUNC (shaper, object) (hb_##object##_t *object)
  84
  85 #define HB_SHAPER_DATA_DESTROY(shaper, object) \
  86     if (HB_SHAPER_DATA_TYPE (shaper, object) *data = HB_SHAPER_DATA (shaper, object)) \
  87       if (data != HB_SHAPER_DATA_INVALID && data != HB_SHAPER_DATA_SUCCEEDED) \
  88         HB_SHAPER_DATA_DESTROY_FUNC (shaper, object) (data);
  89
  90 #define HB_SHAPER_DATA_ENSURE_DEFINE(shaper, object) \
  91         HB_SHAPER_DATA_ENSURE_DEFINE_WITH_CONDITION(shaper, object, true)
  92
  93 #define HB_SHAPER_DATA_ENSURE_DEFINE_WITH_CONDITION(shaper, object, condition) \
  94 bool \
  95 HB_SHAPER_DATA_ENSURE_FUNC(shaper, object) (hb_##object##_t *object) \
  96 {\
  97   retry: \
  98   HB_SHAPER_DATA_TYPE (shaper, object) *data = (HB_SHAPER_DATA_TYPE (shaper, object) *) hb_atomic_ptr_get (&HB_SHAPER_DATA (shaper, object)); \
  99   if (likely (data) && !(condition)) { \
 100     /* Drop and recreate. */ \
 101     /* If someone dropped it in the mean time, throw it away and don't touch it. \
 102      * Otherwise, destruct it. */ \
 103     if (hb_atomic_ptr_cmpexch (&HB_SHAPER_DATA (shaper, object), data, nullptr)) { \
 104       HB_SHAPER_DATA_DESTROY_FUNC (shaper, object) (data); \
 105     } \
 106     goto retry; \
 107   } \
 108   if (unlikely (!data)) { \
 109     data = HB_SHAPER_DATA_CREATE_FUNC (shaper, object) (object); \
 110     if (unlikely (!data)) \
 111       data = (HB_SHAPER_DATA_TYPE (shaper, object) *) HB_SHAPER_DATA_INVALID; \
 112     if (!hb_atomic_ptr_cmpexch (&HB_SHAPER_DATA (shaper, object), nullptr, data)) { \
 113       if (data && \
 114           data != HB_SHAPER_DATA_INVALID && \
 115           data != HB_SHAPER_DATA_SUCCEEDED) \
 116         HB_SHAPER_DATA_DESTROY_FUNC (shaper, object) (data); \
 117       goto retry; \
 118     } \
 119   } \
 120   return data != nullptr && !HB_SHAPER_DATA_IS_INVALID (data); \
 121 }
 122
 123
 124 #endif /* HB_SHAPER_PRIVATE_HH */