harfbuzz/src/hb-glib.cc

302 lines
8.0 KiB
C++

/*
* Copyright © 2009 Red Hat, Inc.
* Copyright © 2011 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.hh"
#ifdef HAVE_GLIB
#include "hb-glib.h"
#include "hb-machinery.hh"
/**
* SECTION:hb-glib
* @title: hb-glib
* @short_description: GLib integration
* @include: hb-glib.h
*
* Functions for using HarfBuzz with the GLib library.
*
* HarfBuzz supports using GLib to provide Unicode data, by attaching
* GLib functions to the virtual methods in a #hb_unicode_funcs_t function
* structure.
**/
/**
* hb_glib_script_to_script:
* @script: The GUnicodeScript identifier to query
*
* Fetches the #hb_script_t script that corresponds to the
* specified GUnicodeScript identifier.
*
* Return value: the #hb_script_t script found
*
* Since: 0.9.38
**/
hb_script_t
hb_glib_script_to_script (GUnicodeScript script)
{
return (hb_script_t) g_unicode_script_to_iso15924 (script);
}
/**
* hb_glib_script_from_script:
* @script: The #hb_script_t to query
*
* Fetches the GUnicodeScript identifier that corresponds to the
* specified #hb_script_t script.
*
* Return value: the GUnicodeScript identifier found
*
* Since: 0.9.38
**/
GUnicodeScript
hb_glib_script_from_script (hb_script_t script)
{
return g_unicode_script_from_iso15924 (script);
}
static hb_unicode_combining_class_t
hb_glib_unicode_combining_class (hb_unicode_funcs_t *ufuncs HB_UNUSED,
hb_codepoint_t unicode,
void *user_data HB_UNUSED)
{
return (hb_unicode_combining_class_t) g_unichar_combining_class (unicode);
}
static hb_unicode_general_category_t
hb_glib_unicode_general_category (hb_unicode_funcs_t *ufuncs HB_UNUSED,
hb_codepoint_t unicode,
void *user_data HB_UNUSED)
{
/* hb_unicode_general_category_t and GUnicodeType are identical */
return (hb_unicode_general_category_t) g_unichar_type (unicode);
}
static hb_codepoint_t
hb_glib_unicode_mirroring (hb_unicode_funcs_t *ufuncs HB_UNUSED,
hb_codepoint_t unicode,
void *user_data HB_UNUSED)
{
g_unichar_get_mirror_char (unicode, &unicode);
return unicode;
}
static hb_script_t
hb_glib_unicode_script (hb_unicode_funcs_t *ufuncs HB_UNUSED,
hb_codepoint_t unicode,
void *user_data HB_UNUSED)
{
return hb_glib_script_to_script (g_unichar_get_script (unicode));
}
static hb_bool_t
hb_glib_unicode_compose (hb_unicode_funcs_t *ufuncs HB_UNUSED,
hb_codepoint_t a,
hb_codepoint_t b,
hb_codepoint_t *ab,
void *user_data HB_UNUSED)
{
#if GLIB_CHECK_VERSION(2,29,12)
return g_unichar_compose (a, b, ab);
#endif
/* We don't ifdef-out the fallback code such that compiler always
* sees it and makes sure it's compilable. */
gchar utf8[12];
gchar *normalized;
int len;
hb_bool_t ret;
len = g_unichar_to_utf8 (a, utf8);
len += g_unichar_to_utf8 (b, utf8 + len);
normalized = g_utf8_normalize (utf8, len, G_NORMALIZE_NFC);
len = g_utf8_strlen (normalized, -1);
if (unlikely (!len))
return false;
if (len == 1) {
*ab = g_utf8_get_char (normalized);
ret = true;
} else {
ret = false;
}
g_free (normalized);
return ret;
}
static hb_bool_t
hb_glib_unicode_decompose (hb_unicode_funcs_t *ufuncs HB_UNUSED,
hb_codepoint_t ab,
hb_codepoint_t *a,
hb_codepoint_t *b,
void *user_data HB_UNUSED)
{
#if GLIB_CHECK_VERSION(2,29,12)
return g_unichar_decompose (ab, a, b);
#endif
/* We don't ifdef-out the fallback code such that compiler always
* sees it and makes sure it's compilable. */
gchar utf8[6];
gchar *normalized;
int len;
hb_bool_t ret;
len = g_unichar_to_utf8 (ab, utf8);
normalized = g_utf8_normalize (utf8, len, G_NORMALIZE_NFD);
len = g_utf8_strlen (normalized, -1);
if (unlikely (!len))
return false;
if (len == 1) {
*a = g_utf8_get_char (normalized);
*b = 0;
ret = *a != ab;
} else if (len == 2) {
*a = g_utf8_get_char (normalized);
*b = g_utf8_get_char (g_utf8_next_char (normalized));
/* Here's the ugly part: if ab decomposes to a single character and
* that character decomposes again, we have to detect that and undo
* the second part :-(. */
gchar *recomposed = g_utf8_normalize (normalized, -1, G_NORMALIZE_NFC);
hb_codepoint_t c = g_utf8_get_char (recomposed);
if (c != ab && c != *a) {
*a = c;
*b = 0;
}
g_free (recomposed);
ret = true;
} else {
/* If decomposed to more than two characters, take the last one,
* and recompose the rest to get the first component. */
gchar *end = g_utf8_offset_to_pointer (normalized, len - 1);
gchar *recomposed;
*b = g_utf8_get_char (end);
recomposed = g_utf8_normalize (normalized, end - normalized, G_NORMALIZE_NFC);
/* We expect that recomposed has exactly one character now. */
*a = g_utf8_get_char (recomposed);
g_free (recomposed);
ret = true;
}
g_free (normalized);
return ret;
}
static inline void free_static_glib_funcs ();
static struct hb_glib_unicode_funcs_lazy_loader_t : hb_unicode_funcs_lazy_loader_t<hb_glib_unicode_funcs_lazy_loader_t>
{
static hb_unicode_funcs_t *create ()
{
hb_unicode_funcs_t *funcs = hb_unicode_funcs_create (nullptr);
hb_unicode_funcs_set_combining_class_func (funcs, hb_glib_unicode_combining_class, nullptr, nullptr);
hb_unicode_funcs_set_general_category_func (funcs, hb_glib_unicode_general_category, nullptr, nullptr);
hb_unicode_funcs_set_mirroring_func (funcs, hb_glib_unicode_mirroring, nullptr, nullptr);
hb_unicode_funcs_set_script_func (funcs, hb_glib_unicode_script, nullptr, nullptr);
hb_unicode_funcs_set_compose_func (funcs, hb_glib_unicode_compose, nullptr, nullptr);
hb_unicode_funcs_set_decompose_func (funcs, hb_glib_unicode_decompose, nullptr, nullptr);
hb_unicode_funcs_make_immutable (funcs);
hb_atexit (free_static_glib_funcs);
return funcs;
}
} static_glib_funcs;
static inline
void free_static_glib_funcs ()
{
static_glib_funcs.free_instance ();
}
/**
* hb_glib_get_unicode_funcs:
*
* Fetches a Unicode-functions structure that is populated
* with the appropriate GLib function for each method.
*
* Return value: (transfer none): a pointer to the #hb_unicode_funcs_t Unicode-functions structure
*
* Since: 0.9.38
**/
hb_unicode_funcs_t *
hb_glib_get_unicode_funcs ()
{
return static_glib_funcs.get_unconst ();
}
#if GLIB_CHECK_VERSION(2,31,10)
static void
_hb_g_bytes_unref (void *data)
{
g_bytes_unref ((GBytes *) data);
}
/**
* hb_glib_blob_create:
* @gbytes: the GBytes structure to work upon
*
* Creates an #hb_blob_t blob from the specified
* GBytes data structure.
*
* Return value: (transfer full): the new #hb_blob_t blob object
*
* Since: 0.9.38
**/
hb_blob_t *
hb_glib_blob_create (GBytes *gbytes)
{
gsize size = 0;
gconstpointer data = g_bytes_get_data (gbytes, &size);
return hb_blob_create ((const char *) data,
size,
HB_MEMORY_MODE_READONLY,
g_bytes_ref (gbytes),
_hb_g_bytes_unref);
}
#endif
#endif