michael@0: /*
michael@0:  * Copyright © 2009  Red Hat, Inc.
michael@0:  * Copyright © 2012  Google, Inc.
michael@0:  *
michael@0:  *  This is part of HarfBuzz, a text shaping library.
michael@0:  *
michael@0:  * Permission is hereby granted, without written agreement and without
michael@0:  * license or royalty fees, to use, copy, modify, and distribute this
michael@0:  * software and its documentation for any purpose, provided that the
michael@0:  * above copyright notice and the following two paragraphs appear in
michael@0:  * all copies of this software.
michael@0:  *
michael@0:  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
michael@0:  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
michael@0:  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
michael@0:  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
michael@0:  * DAMAGE.
michael@0:  *
michael@0:  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
michael@0:  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
michael@0:  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
michael@0:  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
michael@0:  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
michael@0:  *
michael@0:  * Red Hat Author(s): Behdad Esfahbod
michael@0:  * Google Author(s): Behdad Esfahbod
michael@0:  */
michael@0: 
michael@0: #include "hb-private.hh"
michael@0: 
michael@0: #include "hb-shaper-private.hh"
michael@0: #include "hb-shape-plan-private.hh"
michael@0: #include "hb-buffer-private.hh"
michael@0: #include "hb-font-private.hh"
michael@0: 
michael@0: 
michael@0: static void
michael@0: parse_space (const char **pp, const char *end)
michael@0: {
michael@0:   char c;
michael@0:   while (*pp < end && (c = **pp, ISSPACE (c)))
michael@0:     (*pp)++;
michael@0: }
michael@0: 
michael@0: static hb_bool_t
michael@0: parse_char (const char **pp, const char *end, char c)
michael@0: {
michael@0:   parse_space (pp, end);
michael@0: 
michael@0:   if (*pp == end || **pp != c)
michael@0:     return false;
michael@0: 
michael@0:   (*pp)++;
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: static hb_bool_t
michael@0: parse_uint (const char **pp, const char *end, unsigned int *pv)
michael@0: {
michael@0:   char buf[32];
michael@0:   unsigned int len = MIN (ARRAY_LENGTH (buf) - 1, (unsigned int) (end - *pp));
michael@0:   strncpy (buf, *pp, len);
michael@0:   buf[len] = '\0';
michael@0: 
michael@0:   char *p = buf;
michael@0:   char *pend = p;
michael@0:   unsigned int v;
michael@0: 
michael@0:   /* Intentionally use strtol instead of strtoul, such that
michael@0:    * -1 turns into "big number"... */
michael@0:   errno = 0;
michael@0:   v = strtol (p, &pend, 0);
michael@0:   if (errno || p == pend)
michael@0:     return false;
michael@0: 
michael@0:   *pv = v;
michael@0:   *pp += pend - p;
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: static hb_bool_t
michael@0: parse_feature_value_prefix (const char **pp, const char *end, hb_feature_t *feature)
michael@0: {
michael@0:   if (parse_char (pp, end, '-'))
michael@0:     feature->value = 0;
michael@0:   else {
michael@0:     parse_char (pp, end, '+');
michael@0:     feature->value = 1;
michael@0:   }
michael@0: 
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: static hb_bool_t
michael@0: parse_feature_tag (const char **pp, const char *end, hb_feature_t *feature)
michael@0: {
michael@0:   const char *p = *pp;
michael@0:   char c;
michael@0: 
michael@0:   parse_space (pp, end);
michael@0: 
michael@0: #define ISALNUM(c) (('a' <= (c) && (c) <= 'z') || ('A' <= (c) && (c) <= 'Z') || ('0' <= (c) && (c) <= '9'))
michael@0:   while (*pp < end && (c = **pp, ISALNUM(c)))
michael@0:     (*pp)++;
michael@0: #undef ISALNUM
michael@0: 
michael@0:   if (p == *pp)
michael@0:     return false;
michael@0: 
michael@0:   feature->tag = hb_tag_from_string (p, *pp - p);
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: static hb_bool_t
michael@0: parse_feature_indices (const char **pp, const char *end, hb_feature_t *feature)
michael@0: {
michael@0:   parse_space (pp, end);
michael@0: 
michael@0:   hb_bool_t has_start;
michael@0: 
michael@0:   feature->start = 0;
michael@0:   feature->end = (unsigned int) -1;
michael@0: 
michael@0:   if (!parse_char (pp, end, '['))
michael@0:     return true;
michael@0: 
michael@0:   has_start = parse_uint (pp, end, &feature->start);
michael@0: 
michael@0:   if (parse_char (pp, end, ':')) {
michael@0:     parse_uint (pp, end, &feature->end);
michael@0:   } else {
michael@0:     if (has_start)
michael@0:       feature->end = feature->start + 1;
michael@0:   }
michael@0: 
michael@0:   return parse_char (pp, end, ']');
michael@0: }
michael@0: 
michael@0: static hb_bool_t
michael@0: parse_feature_value_postfix (const char **pp, const char *end, hb_feature_t *feature)
michael@0: {
michael@0:   return !parse_char (pp, end, '=') || parse_uint (pp, end, &feature->value);
michael@0: }
michael@0: 
michael@0: 
michael@0: static hb_bool_t
michael@0: parse_one_feature (const char **pp, const char *end, hb_feature_t *feature)
michael@0: {
michael@0:   return parse_feature_value_prefix (pp, end, feature) &&
michael@0: 	 parse_feature_tag (pp, end, feature) &&
michael@0: 	 parse_feature_indices (pp, end, feature) &&
michael@0: 	 parse_feature_value_postfix (pp, end, feature) &&
michael@0: 	 *pp == end;
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * hb_feature_from_string:
michael@0:  * @str: (array length=len):
michael@0:  * @len: 
michael@0:  * @feature: (out):
michael@0:  *
michael@0:  * 
michael@0:  *
michael@0:  * Return value: 
michael@0:  *
michael@0:  * Since: 1.0
michael@0:  **/
michael@0: hb_bool_t
michael@0: hb_feature_from_string (const char *str, int len,
michael@0: 			hb_feature_t *feature)
michael@0: {
michael@0:   if (len < 0)
michael@0:     len = strlen (str);
michael@0: 
michael@0:   return parse_one_feature (&str, str + len, feature);
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * hb_feature_to_string:
michael@0:  * @feature: 
michael@0:  * @buf: (array length=size):
michael@0:  * @size: 
michael@0:  *
michael@0:  * 
michael@0:  *
michael@0:  * Since: 1.0
michael@0:  **/
michael@0: void
michael@0: hb_feature_to_string (hb_feature_t *feature,
michael@0: 		      char *buf, unsigned int size)
michael@0: {
michael@0:   if (unlikely (!size)) return;
michael@0: 
michael@0:   char s[128];
michael@0:   unsigned int len = 0;
michael@0:   if (feature->value == 0)
michael@0:     s[len++] = '-';
michael@0:   hb_tag_to_string (feature->tag, s + len);
michael@0:   len += 4;
michael@0:   while (len && s[len - 1] == ' ')
michael@0:     len--;
michael@0:   if (feature->start != 0 || feature->end != (unsigned int) -1)
michael@0:   {
michael@0:     s[len++] = '[';
michael@0:     if (feature->start)
michael@0:       len += MAX (0, snprintf (s + len, ARRAY_LENGTH (s) - len, "%d", feature->start));
michael@0:     if (feature->end != feature->start + 1) {
michael@0:       s[len++] = ':';
michael@0:       if (feature->end != (unsigned int) -1)
michael@0: 	len += MAX (0, snprintf (s + len, ARRAY_LENGTH (s) - len, "%d", feature->end));
michael@0:     }
michael@0:     s[len++] = ']';
michael@0:   }
michael@0:   if (feature->value > 1)
michael@0:   {
michael@0:     s[len++] = '=';
michael@0:     len += MAX (0, snprintf (s + len, ARRAY_LENGTH (s) - len, "%d", feature->value));
michael@0:   }
michael@0:   assert (len < ARRAY_LENGTH (s));
michael@0:   len = MIN (len, size - 1);
michael@0:   memcpy (buf, s, len);
michael@0:   buf[len] = '\0';
michael@0: }
michael@0: 
michael@0: 
michael@0: static const char **static_shaper_list;
michael@0: 
michael@0: static inline
michael@0: void free_static_shaper_list (void)
michael@0: {
michael@0:   free (static_shaper_list);
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * hb_shape_list_shapers:
michael@0:  *
michael@0:  * 
michael@0:  *
michael@0:  * Return value: (transfer none):
michael@0:  *
michael@0:  * Since: 1.0
michael@0:  **/
michael@0: const char **
michael@0: hb_shape_list_shapers (void)
michael@0: {
michael@0: retry:
michael@0:   const char **shaper_list = (const char **) hb_atomic_ptr_get (&static_shaper_list);
michael@0: 
michael@0:   if (unlikely (!shaper_list))
michael@0:   {
michael@0:     /* Not found; allocate one. */
michael@0:     shaper_list = (const char **) calloc (1 + HB_SHAPERS_COUNT, sizeof (const char *));
michael@0:     if (unlikely (!shaper_list)) {
michael@0:       static const char *nil_shaper_list[] = {NULL};
michael@0:       return nil_shaper_list;
michael@0:     }
michael@0: 
michael@0:     const hb_shaper_pair_t *shapers = _hb_shapers_get ();
michael@0:     unsigned int i;
michael@0:     for (i = 0; i < HB_SHAPERS_COUNT; i++)
michael@0:       shaper_list[i] = shapers[i].name;
michael@0:     shaper_list[i] = NULL;
michael@0: 
michael@0:     if (!hb_atomic_ptr_cmpexch (&static_shaper_list, NULL, shaper_list)) {
michael@0:       free (shaper_list);
michael@0:       goto retry;
michael@0:     }
michael@0: 
michael@0: #ifdef HAVE_ATEXIT
michael@0:     atexit (free_static_shaper_list); /* First person registers atexit() callback. */
michael@0: #endif
michael@0:   }
michael@0: 
michael@0:   return shaper_list;
michael@0: }
michael@0: 
michael@0: 
michael@0: /**
michael@0:  * hb_shape_full:
michael@0:  * @font: a font.
michael@0:  * @buffer: a buffer.
michael@0:  * @features: (array length=num_features):
michael@0:  * @num_features: 
michael@0:  * @shaper_list: (array zero-terminated=1):
michael@0:  *
michael@0:  * 
michael@0:  *
michael@0:  * Return value: 
michael@0:  *
michael@0:  * Since: 1.0
michael@0:  **/
michael@0: hb_bool_t
michael@0: hb_shape_full (hb_font_t          *font,
michael@0: 	       hb_buffer_t        *buffer,
michael@0: 	       const hb_feature_t *features,
michael@0: 	       unsigned int        num_features,
michael@0: 	       const char * const *shaper_list)
michael@0: {
michael@0:   if (unlikely (!buffer->len))
michael@0:     return true;
michael@0: 
michael@0:   assert (buffer->content_type == HB_BUFFER_CONTENT_TYPE_UNICODE);
michael@0: 
michael@0:   hb_shape_plan_t *shape_plan = hb_shape_plan_create_cached (font->face, &buffer->props, features, num_features, shaper_list);
michael@0:   hb_bool_t res = hb_shape_plan_execute (shape_plan, font, buffer, features, num_features);
michael@0:   hb_shape_plan_destroy (shape_plan);
michael@0: 
michael@0:   if (res)
michael@0:     buffer->content_type = HB_BUFFER_CONTENT_TYPE_GLYPHS;
michael@0:   return res;
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * hb_shape:
michael@0:  * @font: a font.
michael@0:  * @buffer: a buffer.
michael@0:  * @features: (array length=num_features):
michael@0:  * @num_features: 
michael@0:  *
michael@0:  * 
michael@0:  *
michael@0:  * Since: 1.0
michael@0:  **/
michael@0: void
michael@0: hb_shape (hb_font_t           *font,
michael@0: 	  hb_buffer_t         *buffer,
michael@0: 	  const hb_feature_t  *features,
michael@0: 	  unsigned int         num_features)
michael@0: {
michael@0:   hb_shape_full (font, buffer, features, num_features, NULL);
michael@0: }