harfbuzz/src/hb-shape.cc

162 lines
4.8 KiB
C++

/*
* Copyright © 2009 Red Hat, Inc.
* 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.
*
* Red Hat Author(s): Behdad Esfahbod
* Google Author(s): Behdad Esfahbod
*/
#include "hb-private.hh"
#include "hb-shaper-private.hh"
#include "hb-shape-plan-private.hh"
#include "hb-buffer-private.hh"
#include "hb-font-private.hh"
/**
* SECTION:hb-shape
* @title: Shaping
* @short_description: Conversion of text strings into positioned glyphs
* @include: hb.h
*
* Shaping is the central operation of HarfBuzz. Shaping operates on buffers,
* which are sequences of Unicode characters that use the same font and have
* the same text direction, script and language. After shaping the buffer
* contains the output glyphs and their positions.
**/
static const char **static_shaper_list;
#ifdef HB_USE_ATEXIT
static
void free_static_shaper_list (void)
{
free (static_shaper_list);
}
#endif
/**
* hb_shape_list_shapers:
*
* Retrieves the list of shapers supported by HarfBuzz.
*
* Return value: (transfer none) (array zero-terminated=1): an array of
* constant strings
*
* Since: 0.9.2
**/
const char **
hb_shape_list_shapers (void)
{
retry:
const char **shaper_list = (const char **) hb_atomic_ptr_get (&static_shaper_list);
if (unlikely (!shaper_list))
{
/* Not found; allocate one. */
shaper_list = (const char **) calloc (1 + HB_SHAPERS_COUNT, sizeof (const char *));
if (unlikely (!shaper_list)) {
static const char *nil_shaper_list[] = {nullptr};
return nil_shaper_list;
}
const hb_shaper_pair_t *shapers = _hb_shapers_get ();
unsigned int i;
for (i = 0; i < HB_SHAPERS_COUNT; i++)
shaper_list[i] = shapers[i].name;
shaper_list[i] = nullptr;
if (!hb_atomic_ptr_cmpexch (&static_shaper_list, nullptr, shaper_list)) {
free (shaper_list);
goto retry;
}
#ifdef HB_USE_ATEXIT
atexit (free_static_shaper_list); /* First person registers atexit() callback. */
#endif
}
return shaper_list;
}
/**
* hb_shape_full:
* @font: an #hb_font_t to use for shaping
* @buffer: an #hb_buffer_t to shape
* @features: (array length=num_features) (allow-none): an array of user
* specified #hb_feature_t or %NULL
* @num_features: the length of @features array
* @shaper_list: (array zero-terminated=1) (allow-none): a %NULL-terminated
* array of shapers to use or %NULL
*
* See hb_shape() for details. If @shaper_list is not %NULL, the specified
* shapers will be used in the given order, otherwise the default shapers list
* will be used.
*
* Return value: false if all shapers failed, true otherwise
*
* Since: 0.9.2
**/
hb_bool_t
hb_shape_full (hb_font_t *font,
hb_buffer_t *buffer,
const hb_feature_t *features,
unsigned int num_features,
const char * const *shaper_list)
{
hb_shape_plan_t *shape_plan = hb_shape_plan_create_cached2 (font->face, &buffer->props,
features, num_features,
font->coords, font->num_coords,
shaper_list);
hb_bool_t res = hb_shape_plan_execute (shape_plan, font, buffer, features, num_features);
hb_shape_plan_destroy (shape_plan);
if (res)
buffer->content_type = HB_BUFFER_CONTENT_TYPE_GLYPHS;
return res;
}
/**
* hb_shape:
* @font: an #hb_font_t to use for shaping
* @buffer: an #hb_buffer_t to shape
* @features: (array length=num_features) (allow-none): an array of user
* specified #hb_feature_t or %NULL
* @num_features: the length of @features array
*
* Shapes @buffer using @font turning its Unicode characters content to
* positioned glyphs. If @features is not %NULL, it will be used to control the
* features applied during shaping.
*
* Since: 0.9.2
**/
void
hb_shape (hb_font_t *font,
hb_buffer_t *buffer,
const hb_feature_t *features,
unsigned int num_features)
{
hb_shape_full (font, buffer, features, num_features, nullptr);
}