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.hh"
28 #include "hb-shaper.hh"
29 #include "hb-machinery.hh"
30
31
32 static const hb_shaper_entry_t all_shapers[] = {
33 #define HB_SHAPER_IMPLEMENT(name) {#name, _hb_##name##_shape},
34 #include "hb-shaper-list.hh"
35 #undef HB_SHAPER_IMPLEMENT
36 };
37 #ifndef HB_NO_SHAPER
38 static_assert (0 != ARRAY_LENGTH_CONST (all_shapers), "No shaper enabled.");
39 #endif
40
41 static inline void free_static_shapers ();
42
43 static struct hb_shapers_lazy_loader_t : hb_lazy_loader_t<const hb_shaper_entry_t,
44 hb_shapers_lazy_loader_t>
45 {
createhb_shapers_lazy_loader_t46 static hb_shaper_entry_t *create ()
47 {
48 char *env = getenv ("HB_SHAPER_LIST");
49 if (!env || !*env)
50 return nullptr;
51
52 hb_shaper_entry_t *shapers = (hb_shaper_entry_t *) hb_calloc (1, sizeof (all_shapers));
53 if (unlikely (!shapers))
54 return nullptr;
55
56 memcpy (shapers, all_shapers, sizeof (all_shapers));
57
58 /* Reorder shaper list to prefer requested shapers. */
59 unsigned int i = 0;
60 char *end, *p = env;
61 for (;;)
62 {
63 end = strchr (p, ',');
64 if (!end)
65 end = p + strlen (p);
66
67 for (unsigned int j = i; j < ARRAY_LENGTH (all_shapers); j++)
68 if (end - p == (int) strlen (shapers[j].name) &&
69 0 == strncmp (shapers[j].name, p, end - p))
70 {
71 /* Reorder this shaper to position i */
72 struct hb_shaper_entry_t t = shapers[j];
73 memmove (&shapers[i + 1], &shapers[i], sizeof (shapers[i]) * (j - i));
74 shapers[i] = t;
75 i++;
76 }
77
78 if (!*end)
79 break;
80 else
81 p = end + 1;
82 }
83
84 hb_atexit (free_static_shapers);
85
86 return shapers;
87 }
destroyhb_shapers_lazy_loader_t88 static void destroy (const hb_shaper_entry_t *p) { hb_free ((void *) p); }
get_nullhb_shapers_lazy_loader_t89 static const hb_shaper_entry_t *get_null () { return all_shapers; }
90 } static_shapers;
91
92 static inline
free_static_shapers()93 void free_static_shapers ()
94 {
95 static_shapers.free_instance ();
96 }
97
98 const hb_shaper_entry_t *
_hb_shapers_get()99 _hb_shapers_get ()
100 {
101 return static_shapers.get_unconst ();
102 }
103