harfbuzz/src/hb-shaper.cc
2018-12-17 13:01:01 -05:00

106 lines
2.8 KiB
C++

/*
* Copyright © 2012 Google, Inc.
*
* This is part of HarfBuzz, a text shaping library.
*
* Permission is hereby granted, without written agreement and without
* license or royalty fees, to use, copy, modify, and distribute this
* software and its documentation for any purpose, provided that the
* above copyright notice and the following two paragraphs appear in
* all copies of this software.
*
* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
* Google Author(s): Behdad Esfahbod
*/
#include "hb.hh"
#include "hb-shaper.hh"
#include "hb-machinery.hh"
static const hb_shaper_entry_t all_shapers[] = {
#define HB_SHAPER_IMPLEMENT(name) {#name, _hb_##name##_shape},
#include "hb-shaper-list.hh"
#undef HB_SHAPER_IMPLEMENT
};
#if HB_USE_ATEXIT
static void free_static_shapers ();
#endif
static struct hb_shapers_lazy_loader_t : hb_lazy_loader_t<const hb_shaper_entry_t,
hb_shapers_lazy_loader_t>
{
static hb_shaper_entry_t *create ()
{
char *env = getenv ("HB_SHAPER_LIST");
if (!env || !*env)
return nullptr;
hb_shaper_entry_t *shapers = (hb_shaper_entry_t *) calloc (1, sizeof (all_shapers));
if (unlikely (!shapers))
return nullptr;
memcpy (shapers, all_shapers, sizeof (all_shapers));
/* Reorder shaper list to prefer requested shapers. */
unsigned int i = 0;
char *end, *p = env;
for (;;)
{
end = strchr (p, ',');
if (!end)
end = p + strlen (p);
for (unsigned int j = i; j < ARRAY_LENGTH (all_shapers); j++)
if (end - p == (int) strlen (shapers[j].name) &&
0 == strncmp (shapers[j].name, p, end - p))
{
/* Reorder this shaper to position i */
struct hb_shaper_entry_t t = shapers[j];
memmove (&shapers[i + 1], &shapers[i], sizeof (shapers[i]) * (j - i));
shapers[i] = t;
i++;
}
if (!*end)
break;
else
p = end + 1;
}
#if HB_USE_ATEXIT
atexit (free_static_shapers);
#endif
return shapers;
}
static void destroy (const hb_shaper_entry_t *p) { free ((void *) p); }
static const hb_shaper_entry_t *get_null () { return all_shapers; }
} static_shapers;
#if HB_USE_ATEXIT
static
void free_static_shapers ()
{
static_shapers.free_instance ();
}
#endif
const hb_shaper_entry_t *
_hb_shapers_get ()
{
return static_shapers.get_unconst ();
}