407 lines
10 KiB
C++
407 lines
10 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 bool
|
|
parse_space (const char **pp, const char *end)
|
|
{
|
|
while (*pp < end && ISSPACE (**pp))
|
|
(*pp)++;
|
|
return true;
|
|
}
|
|
|
|
static bool
|
|
parse_char (const char **pp, const char *end, char c)
|
|
{
|
|
parse_space (pp, end);
|
|
|
|
if (*pp == end || **pp != c)
|
|
return false;
|
|
|
|
(*pp)++;
|
|
return true;
|
|
}
|
|
|
|
static bool
|
|
parse_uint (const char **pp, const char *end, unsigned int *pv)
|
|
{
|
|
char buf[32];
|
|
unsigned int len = MIN (ARRAY_LENGTH (buf) - 1, (unsigned int) (end - *pp));
|
|
strncpy (buf, *pp, len);
|
|
buf[len] = '\0';
|
|
|
|
char *p = buf;
|
|
char *pend = p;
|
|
unsigned int v;
|
|
|
|
/* Intentionally use strtol instead of strtoul, such that
|
|
* -1 turns into "big number"... */
|
|
errno = 0;
|
|
v = strtol (p, &pend, 0);
|
|
if (errno || p == pend)
|
|
return false;
|
|
|
|
*pv = v;
|
|
*pp += pend - p;
|
|
return true;
|
|
}
|
|
|
|
static bool
|
|
parse_bool (const char **pp, const char *end, unsigned int *pv)
|
|
{
|
|
parse_space (pp, end);
|
|
|
|
const char *p = *pp;
|
|
while (*pp < end && ISALPHA(**pp))
|
|
(*pp)++;
|
|
|
|
/* CSS allows on/off as aliases 1/0. */
|
|
if (*pp - p == 2 || 0 == strncmp (p, "on", 2))
|
|
*pv = 1;
|
|
else if (*pp - p == 3 || 0 == strncmp (p, "off", 2))
|
|
*pv = 0;
|
|
else
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
static bool
|
|
parse_feature_value_prefix (const char **pp, const char *end, hb_feature_t *feature)
|
|
{
|
|
if (parse_char (pp, end, '-'))
|
|
feature->value = 0;
|
|
else {
|
|
parse_char (pp, end, '+');
|
|
feature->value = 1;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static bool
|
|
parse_feature_tag (const char **pp, const char *end, hb_feature_t *feature)
|
|
{
|
|
parse_space (pp, end);
|
|
|
|
char quote = 0;
|
|
|
|
if (*pp < end && (**pp == '\'' || **pp == '"'))
|
|
{
|
|
quote = **pp;
|
|
(*pp)++;
|
|
}
|
|
|
|
const char *p = *pp;
|
|
while (*pp < end && ISALNUM(**pp))
|
|
(*pp)++;
|
|
|
|
if (p == *pp || *pp - p > 4)
|
|
return false;
|
|
|
|
feature->tag = hb_tag_from_string (p, *pp - p);
|
|
|
|
if (quote)
|
|
{
|
|
/* CSS expects exactly four bytes. And we only allow quotations for
|
|
* CSS compatibility. So, enforce the length. */
|
|
if (*pp - p != 4)
|
|
return false;
|
|
if (*pp == end || **pp != quote)
|
|
return false;
|
|
(*pp)++;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static bool
|
|
parse_feature_indices (const char **pp, const char *end, hb_feature_t *feature)
|
|
{
|
|
parse_space (pp, end);
|
|
|
|
bool has_start;
|
|
|
|
feature->start = 0;
|
|
feature->end = (unsigned int) -1;
|
|
|
|
if (!parse_char (pp, end, '['))
|
|
return true;
|
|
|
|
has_start = parse_uint (pp, end, &feature->start);
|
|
|
|
if (parse_char (pp, end, ':')) {
|
|
parse_uint (pp, end, &feature->end);
|
|
} else {
|
|
if (has_start)
|
|
feature->end = feature->start + 1;
|
|
}
|
|
|
|
return parse_char (pp, end, ']');
|
|
}
|
|
|
|
static bool
|
|
parse_feature_value_postfix (const char **pp, const char *end, hb_feature_t *feature)
|
|
{
|
|
bool had_equal = parse_char (pp, end, '=');
|
|
bool had_value = parse_uint (pp, end, &feature->value) ||
|
|
parse_bool (pp, end, &feature->value);
|
|
/* CSS doesn't use equal-sign between tag and value.
|
|
* If there was an equal-sign, then there *must* be a value.
|
|
* A value without an eqaul-sign is ok, but not required. */
|
|
return !had_equal || had_value;
|
|
}
|
|
|
|
|
|
static bool
|
|
parse_one_feature (const char **pp, const char *end, hb_feature_t *feature)
|
|
{
|
|
return parse_feature_value_prefix (pp, end, feature) &&
|
|
parse_feature_tag (pp, end, feature) &&
|
|
parse_feature_indices (pp, end, feature) &&
|
|
parse_feature_value_postfix (pp, end, feature) &&
|
|
parse_space (pp, end) &&
|
|
*pp == end;
|
|
}
|
|
|
|
/**
|
|
* hb_feature_from_string:
|
|
* @str: (array length=len) (element-type uint8_t): a string to parse
|
|
* @len: length of @str, or -1 if string is %NULL terminated
|
|
* @feature: (out): the #hb_feature_t to initialize with the parsed values
|
|
*
|
|
* Parses a string into a #hb_feature_t.
|
|
*
|
|
* TODO: document the syntax here.
|
|
*
|
|
* Return value:
|
|
* %true if @str is successfully parsed, %false otherwise.
|
|
*
|
|
* Since: 0.9.5
|
|
**/
|
|
hb_bool_t
|
|
hb_feature_from_string (const char *str, int len,
|
|
hb_feature_t *feature)
|
|
{
|
|
hb_feature_t feat;
|
|
|
|
if (len < 0)
|
|
len = strlen (str);
|
|
|
|
if (likely (parse_one_feature (&str, str + len, &feat)))
|
|
{
|
|
if (feature)
|
|
*feature = feat;
|
|
return true;
|
|
}
|
|
|
|
if (feature)
|
|
memset (feature, 0, sizeof (*feature));
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* hb_feature_to_string:
|
|
* @feature: an #hb_feature_t to convert
|
|
* @buf: (array length=size) (out): output string
|
|
* @size: the allocated size of @buf
|
|
*
|
|
* Converts a #hb_feature_t into a %NULL-terminated string in the format
|
|
* understood by hb_feature_from_string(). The client in responsible for
|
|
* allocating big enough size for @buf, 128 bytes is more than enough.
|
|
*
|
|
* Since: 0.9.5
|
|
**/
|
|
void
|
|
hb_feature_to_string (hb_feature_t *feature,
|
|
char *buf, unsigned int size)
|
|
{
|
|
if (unlikely (!size)) return;
|
|
|
|
char s[128];
|
|
unsigned int len = 0;
|
|
if (feature->value == 0)
|
|
s[len++] = '-';
|
|
hb_tag_to_string (feature->tag, s + len);
|
|
len += 4;
|
|
while (len && s[len - 1] == ' ')
|
|
len--;
|
|
if (feature->start != 0 || feature->end != (unsigned int) -1)
|
|
{
|
|
s[len++] = '[';
|
|
if (feature->start)
|
|
len += MAX (0, snprintf (s + len, ARRAY_LENGTH (s) - len, "%u", feature->start));
|
|
if (feature->end != feature->start + 1) {
|
|
s[len++] = ':';
|
|
if (feature->end != (unsigned int) -1)
|
|
len += MAX (0, snprintf (s + len, ARRAY_LENGTH (s) - len, "%u", feature->end));
|
|
}
|
|
s[len++] = ']';
|
|
}
|
|
if (feature->value > 1)
|
|
{
|
|
s[len++] = '=';
|
|
len += MAX (0, snprintf (s + len, ARRAY_LENGTH (s) - len, "%u", feature->value));
|
|
}
|
|
assert (len < ARRAY_LENGTH (s));
|
|
len = MIN (len, size - 1);
|
|
memcpy (buf, s, len);
|
|
buf[len] = '\0';
|
|
}
|
|
|
|
|
|
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[] = {NULL};
|
|
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] = NULL;
|
|
|
|
if (!hb_atomic_ptr_cmpexch (&static_shaper_list, NULL, 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_cached (font->face, &buffer->props, features, num_features, 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, NULL);
|
|
}
|