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(shaper, object)		struct hb_##shaper##_shaper_##object##_data_t
69 #define HB_SHAPER_DATA_INSTANCE(shaper, object, instance)	(* (HB_SHAPER_DATA_TYPE(shaper, object) **) &(instance)->shaper_data.shaper)
70 #define HB_SHAPER_DATA(shaper, object)			HB_SHAPER_DATA_INSTANCE (shaper, object, object)
71 #define HB_SHAPER_DATA_CREATE_FUNC(shaper, object)	_hb_##shaper##_shaper_##object##_data_create
72 #define HB_SHAPER_DATA_DESTROY_FUNC(shaper, object)	_hb_##shaper##_shaper_##object##_data_destroy
73 
74 #define HB_SHAPER_DATA_PROTOTYPE(shaper, object) \
75 	HB_SHAPER_DATA_TYPE (shaper, object); /* Type forward declaration. */ \
76 	extern "C" HB_INTERNAL HB_SHAPER_DATA_TYPE (shaper, object) * \
77 	HB_SHAPER_DATA_CREATE_FUNC (shaper, object) (hb_##object##_t *object HB_SHAPER_DATA_CREATE_FUNC_EXTRA_ARGS); \
78 	extern "C" HB_INTERNAL void \
79 	HB_SHAPER_DATA_DESTROY_FUNC (shaper, object) (HB_SHAPER_DATA_TYPE (shaper, object) *data)
80 
81 #define HB_SHAPER_DATA_DESTROY(shaper, object) \
82     if (HB_SHAPER_DATA_TYPE (shaper, object) *data = HB_SHAPER_DATA (shaper, object)) \
83       if (data != HB_SHAPER_DATA_INVALID && data != HB_SHAPER_DATA_SUCCEEDED) \
84         HB_SHAPER_DATA_DESTROY_FUNC (shaper, object) (data);
85 
86 #define HB_SHAPER_DATA_ENSURE_DECLARE(shaper, object) \
87 static inline bool \
88 hb_##shaper##_shaper_##object##_data_ensure (hb_##object##_t *object) \
89 {\
90   retry: \
91   HB_SHAPER_DATA_TYPE (shaper, object) *data = (HB_SHAPER_DATA_TYPE (shaper, object) *) hb_atomic_ptr_get (&HB_SHAPER_DATA (shaper, object)); \
92   if (unlikely (!data)) { \
93     data = HB_SHAPER_DATA_CREATE_FUNC (shaper, object) (object); \
94     if (unlikely (!data)) \
95       data = (HB_SHAPER_DATA_TYPE (shaper, object) *) HB_SHAPER_DATA_INVALID; \
96     if (!hb_atomic_ptr_cmpexch (&HB_SHAPER_DATA (shaper, object), NULL, data)) { \
97       if (data && \
98 	  data != HB_SHAPER_DATA_INVALID && \
99 	  data != HB_SHAPER_DATA_SUCCEEDED) \
100 	HB_SHAPER_DATA_DESTROY_FUNC (shaper, object) (data); \
101       goto retry; \
102     } \
103   } \
104   return data != NULL && !HB_SHAPER_DATA_IS_INVALID (data); \
105 }
106 
107 
108 #endif /* HB_SHAPER_PRIVATE_HH */
109