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 /*

  * 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"

 static void

 parse_space (const char **pp, const char *end)

 {

   char c;

   while (*pp < end && (c = **pp, ISSPACE (c)))

     (*pp)++;

 }

 static hb_bool_t

 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 hb_bool_t

 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 hb_bool_t

 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 hb_bool_t

 parse_feature_tag (const char **pp, const char *end, hb_feature_t *feature)

 {

   const char *p = *pp;

   char c;

   parse_space (pp, end);

 #define ISALNUM(c) (('a' <= (c) && (c) <= 'z') || ('A' <= (c) && (c) <= 'Z') || ('0' <= (c) && (c) <= '9'))

   while (*pp < end && (c = **pp, ISALNUM(c)))

     (*pp)++;

 #undef ISALNUM

   if (p == *pp)

     return false;

   feature->tag = hb_tag_from_string (p, *pp - p);

   return true;

 }

 static hb_bool_t

 parse_feature_indices (const char **pp, const char *end, hb_feature_t *feature)

 {

   parse_space (pp, end);

   hb_bool_t 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 hb_bool_t

 parse_feature_value_postfix (const char **pp, const char *end, hb_feature_t *feature)

 {

   return !parse_char (pp, end, '=') || parse_uint (pp, end, &feature->value);

 }

 static hb_bool_t

 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) &&

 	 *pp == end;

 }

 /**

  * hb_feature_from_string:

  * @str: (array length=len):

  * @len: 

  * @feature: (out):

  *

  * 

  *

  * Return value: 

  *

  * Since: 1.0

  **/

 hb_bool_t

 hb_feature_from_string (const char *str, int len,

 			hb_feature_t *feature)

 {

   if (len < 0)

     len = strlen (str);

   return parse_one_feature (&str, str + len, feature);

 }

 /**

  * hb_feature_to_string:

  * @feature: 

  * @buf: (array length=size):

  * @size: 

  *

  * 

  *

  * Since: 1.0

  **/

 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, "%d", 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, "%d", feature->end));

     }

     s[len++] = ']';

   }

   if (feature->value > 1)

   {

     s[len++] = '=';

     len += MAX (0, snprintf (s + len, ARRAY_LENGTH (s) - len, "%d", 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;

 static inline

 void free_static_shaper_list (void)

 {

   free (static_shaper_list);

 }

 /**

  * hb_shape_list_shapers:

  *

  * 

  *

  * Return value: (transfer none):

  *

  * Since: 1.0

  **/

 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 HAVE_ATEXIT

     atexit (free_static_shaper_list); /* First person registers atexit() callback. */

 #endif

   }

   return shaper_list;

 }

 /**

  * hb_shape_full:

  * @font: a font.

  * @buffer: a buffer.

  * @features: (array length=num_features):

  * @num_features: 

  * @shaper_list: (array zero-terminated=1):

  *

  * 

  *

  * Return value: 

  *

  * Since: 1.0

  **/

 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)

 {

   if (unlikely (!buffer->len))

     return true;

   assert (buffer->content_type == HB_BUFFER_CONTENT_TYPE_UNICODE);

   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: a font.

  * @buffer: a buffer.

  * @features: (array length=num_features):

  * @num_features: 

  *

  * 

  *

  * Since: 1.0

  **/

 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);

 }