tor-browser

hb-ot-tag.cc (18546B)

---

/*
* 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, Roozbeh Pournader
*/

#include "hb.hh"

#ifndef HB_NO_OT_TAG


/* hb_script_t */

static hb_tag_t
hb_ot_old_tag_from_script (hb_script_t script)
{
 /* This seems to be accurate as of end of 2012. */

 switch ((hb_tag_t) script)
 {
   case HB_SCRIPT_INVALID:		return HB_OT_TAG_DEFAULT_SCRIPT;
   case HB_SCRIPT_MATH:		return HB_OT_TAG_MATH_SCRIPT;

   /* KATAKANA and HIRAGANA both map to 'kana' */
   case HB_SCRIPT_HIRAGANA:		return HB_TAG('k','a','n','a');

   /* Spaces at the end are preserved, unlike ISO 15924 */
   case HB_SCRIPT_LAO:			return HB_TAG('l','a','o',' ');
   case HB_SCRIPT_YI:			return HB_TAG('y','i',' ',' ');
   /* Unicode-5.0 additions */
   case HB_SCRIPT_NKO:			return HB_TAG('n','k','o',' ');
   /* Unicode-5.1 additions */
   case HB_SCRIPT_VAI:			return HB_TAG('v','a','i',' ');
 }

 /* Else, just change first char to lowercase and return */
 return ((hb_tag_t) script) | 0x20000000u;
}

static hb_script_t
hb_ot_old_tag_to_script (hb_tag_t tag)
{
 if (unlikely (tag == HB_OT_TAG_DEFAULT_SCRIPT))
   return HB_SCRIPT_INVALID;
 if (unlikely (tag == HB_OT_TAG_MATH_SCRIPT))
   return HB_SCRIPT_MATH;

 /* This side of the conversion is fully algorithmic. */

 /* Any spaces at the end of the tag are replaced by repeating the last
  * letter.  Eg 'nko ' -> 'Nkoo' */
 if (unlikely ((tag & 0x0000FF00u) == 0x00002000u))
   tag |= (tag >> 8) & 0x0000FF00u; /* Copy second letter to third */
 if (unlikely ((tag & 0x000000FFu) == 0x00000020u))
   tag |= (tag >> 8) & 0x000000FFu; /* Copy third letter to fourth */

 /* Change first char to uppercase and return */
 return (hb_script_t) (tag & ~0x20000000u);
}

static hb_tag_t
hb_ot_new_tag_from_script (hb_script_t script)
{
 switch ((hb_tag_t) script) {
   case HB_SCRIPT_BENGALI:		return HB_TAG('b','n','g','2');
   case HB_SCRIPT_DEVANAGARI:		return HB_TAG('d','e','v','2');
   case HB_SCRIPT_GUJARATI:		return HB_TAG('g','j','r','2');
   case HB_SCRIPT_GURMUKHI:		return HB_TAG('g','u','r','2');
   case HB_SCRIPT_KANNADA:		return HB_TAG('k','n','d','2');
   case HB_SCRIPT_MALAYALAM:		return HB_TAG('m','l','m','2');
   case HB_SCRIPT_ORIYA:		return HB_TAG('o','r','y','2');
   case HB_SCRIPT_TAMIL:		return HB_TAG('t','m','l','2');
   case HB_SCRIPT_TELUGU:		return HB_TAG('t','e','l','2');
   case HB_SCRIPT_MYANMAR:		return HB_TAG('m','y','m','2');
 }

 return HB_OT_TAG_DEFAULT_SCRIPT;
}

static hb_script_t
hb_ot_new_tag_to_script (hb_tag_t tag)
{
 switch (tag) {
   case HB_TAG('b','n','g','2'):	return HB_SCRIPT_BENGALI;
   case HB_TAG('d','e','v','2'):	return HB_SCRIPT_DEVANAGARI;
   case HB_TAG('g','j','r','2'):	return HB_SCRIPT_GUJARATI;
   case HB_TAG('g','u','r','2'):	return HB_SCRIPT_GURMUKHI;
   case HB_TAG('k','n','d','2'):	return HB_SCRIPT_KANNADA;
   case HB_TAG('m','l','m','2'):	return HB_SCRIPT_MALAYALAM;
   case HB_TAG('o','r','y','2'):	return HB_SCRIPT_ORIYA;
   case HB_TAG('t','m','l','2'):	return HB_SCRIPT_TAMIL;
   case HB_TAG('t','e','l','2'):	return HB_SCRIPT_TELUGU;
   case HB_TAG('m','y','m','2'):	return HB_SCRIPT_MYANMAR;
 }

 return HB_SCRIPT_UNKNOWN;
}

#ifndef HB_DISABLE_DEPRECATED
/**
* hb_ot_tags_from_script:
* @script: an #hb_script_t to convert.
* @script_tag_1: (out): output #hb_tag_t.
* @script_tag_2: (out): output #hb_tag_t.
*
* Converts an #hb_script_t to script tags.
*
* Since: 0.6.0
* Deprecated: 2.0.0: use hb_ot_tags_from_script_and_language() instead
**/
void
hb_ot_tags_from_script (hb_script_t  script,
		hb_tag_t    *script_tag_1,
		hb_tag_t    *script_tag_2)
{
 unsigned int count = 2;
 hb_tag_t tags[2];
 hb_ot_tags_from_script_and_language (script, HB_LANGUAGE_INVALID, &count, tags, nullptr, nullptr);
 *script_tag_1 = count > 0 ? tags[0] : HB_OT_TAG_DEFAULT_SCRIPT;
 *script_tag_2 = count > 1 ? tags[1] : HB_OT_TAG_DEFAULT_SCRIPT;
}
#endif

/*
* Complete list at:
* https://docs.microsoft.com/en-us/typography/opentype/spec/scripttags
*
* Most of the script tags are the same as the ISO 15924 tag but lowercased.
* So we just do that, and handle the exceptional cases in a switch.
*/

static void
hb_ot_all_tags_from_script (hb_script_t   script,
		    unsigned int *count /* IN/OUT */,
		    hb_tag_t     *tags /* OUT */)
{
 unsigned int i = 0;

 hb_tag_t new_tag = hb_ot_new_tag_from_script (script);
 if (unlikely (new_tag != HB_OT_TAG_DEFAULT_SCRIPT))
 {
   /* HB_SCRIPT_MYANMAR maps to 'mym2', but there is no 'mym3'. */
   if (new_tag != HB_TAG('m','y','m','2'))
     tags[i++] = new_tag | '3';
   if (*count > i)
     tags[i++] = new_tag;
 }

 if (*count > i)
 {
   hb_tag_t old_tag = hb_ot_old_tag_from_script (script);
   if (old_tag != HB_OT_TAG_DEFAULT_SCRIPT)
     tags[i++] = old_tag;
 }

 *count = i;
}

/**
* hb_ot_tag_to_script:
* @tag: a script tag
*
* Converts a script tag to an #hb_script_t.
*
* Return value: The #hb_script_t corresponding to @tag.
*
**/
hb_script_t
hb_ot_tag_to_script (hb_tag_t tag)
{
 unsigned char digit = tag & 0x000000FFu;
 if (unlikely (digit == '2' || digit == '3'))
   return hb_ot_new_tag_to_script (tag & 0xFFFFFF32);

 return hb_ot_old_tag_to_script (tag);
}


/* hb_language_t */

static inline bool
subtag_matches (const char *lang_str,
	const char *limit,
	const char *subtag,
	unsigned    subtag_len)
{
 if (likely ((unsigned) (limit - lang_str) < subtag_len))
   return false;

 do {
   const char *s = strstr (lang_str, subtag);
   if (!s || s >= limit)
     return false;
   if (!ISALNUM (s[subtag_len]))
     return true;
   lang_str = s + subtag_len;
 } while (true);
}

static bool
lang_matches (const char *lang_str,
      const char *limit,
      const char *spec,
      unsigned    spec_len)
{
 /* Same as hb_language_matches(); duplicated. */

 if (likely ((unsigned) (limit - lang_str) < spec_len))
   return false;

 return strncmp (lang_str, spec, spec_len) == 0 &&
 (lang_str[spec_len] == '\0' || lang_str[spec_len] == '-');
}

struct LangTag
{
 hb_tag_t language;
 hb_tag_t tag;

 int cmp (hb_tag_t a) const
 {
   return a < this->language ? -1 : a > this->language ? +1 : 0;
 }
 int cmp (const LangTag *that) const
 { return cmp (that->language); }
};

#include "hb-ot-tag-table.hh"

/* The corresponding languages IDs for the following IDs are unclear,
* overlap, or are architecturally weird. Needs more research. */

/*{"??",	{HB_TAG('B','C','R',' ')}},*/	/* Bible Cree */
/*{"zh?",	{HB_TAG('C','H','N',' ')}},*/	/* Chinese (seen in Microsoft fonts) */
/*{"ar-Syrc?",	{HB_TAG('G','A','R',' ')}},*/	/* Garshuni */
/*{"??",	{HB_TAG('N','G','R',' ')}},*/	/* Nagari */
/*{"??",	{HB_TAG('Y','I','C',' ')}},*/	/* Yi Classic */
/*{"zh?",	{HB_TAG('Z','H','P',' ')}},*/	/* Chinese Phonetic */

#ifndef HB_DISABLE_DEPRECATED
/**
* hb_ot_tag_from_language:
* @language: an #hb_language_t to convert.
*
* Converts an #hb_language_t to an #hb_tag_t.
*
* Since: 0.6.0
* Deprecated: 2.0.0: use hb_ot_tags_from_script_and_language() instead
**/
hb_tag_t
hb_ot_tag_from_language (hb_language_t language)
{
 unsigned int count = 1;
 hb_tag_t tags[1];
 hb_ot_tags_from_script_and_language (HB_SCRIPT_UNKNOWN, language, nullptr, nullptr, &count, tags);
 return count > 0 ? tags[0] : HB_OT_TAG_DEFAULT_LANGUAGE;
}
#endif

static void
hb_ot_tags_from_language (const char   *lang_str,
		  const char   *limit,
		  unsigned int *count,
		  hb_tag_t     *tags)
{

#ifndef HB_NO_LANGUAGE_LONG
 /* Check for matches of multiple subtags. */
 if (hb_ot_tags_from_complex_language (lang_str, limit, count, tags))
   return;
#endif

 /* Find a language matching in the first component. */
#ifndef HB_NO_LANGUAGE_LONG
 const char *s; s = strchr (lang_str, '-');
#endif
 {
#ifndef HB_NO_LANGUAGE_LONG
   if (s && limit - lang_str >= 6)
   {
     const char *extlang_end = strchr (s + 1, '-');
     /* If there is an extended language tag, use it. */
     if (3 == (extlang_end ? extlang_end - s - 1 : strlen (s + 1)) &&
  ISALPHA (s[1]))
lang_str = s + 1;
   }
#endif
   const LangTag *ot_languages = nullptr;
   unsigned ot_languages_len = 0;
   const char *dash = strchr (lang_str, '-');
   unsigned first_len = dash ? dash - lang_str : limit - lang_str;
   if (first_len == 2)
   {
     ot_languages = ot_languages2;
     ot_languages_len = ARRAY_LENGTH (ot_languages2);
   }
#ifndef HB_NO_LANGUAGE_LONG
   else if (first_len == 3)
   {
     ot_languages = ot_languages3;
     ot_languages_len = ARRAY_LENGTH (ot_languages3);
   }
#endif

   hb_tag_t lang_tag = hb_tag_from_string (lang_str, first_len);

   static hb_atomic_t<unsigned> last_tag_idx = 0; /* Poor man's cache. */
   unsigned tag_idx = last_tag_idx;

   if (likely (tag_idx < ot_languages_len && ot_languages[tag_idx].language == lang_tag) ||
hb_sorted_array (ot_languages, ot_languages_len).bfind (lang_tag, &tag_idx))
   {
     last_tag_idx = tag_idx;
     unsigned int i;
     while (tag_idx != 0 &&
     ot_languages[tag_idx].language == ot_languages[tag_idx - 1].language)
tag_idx--;
     for (i = 0;
   i < *count &&
   tag_idx + i < ot_languages_len &&
   ot_languages[tag_idx + i].tag != HB_TAG_NONE &&
   ot_languages[tag_idx + i].language == ot_languages[tag_idx].language;
   i++)
tags[i] = ot_languages[tag_idx + i].tag;
     *count = i;
     return;
   }
 }

#ifndef HB_NO_LANGUAGE_LONG
 if (!s)
   s = lang_str + strlen (lang_str);
 if (s - lang_str == 3) {
   /* Assume it's ISO-639-3 and upper-case and use it. */
   tags[0] = hb_tag_from_string (lang_str, s - lang_str) & ~0x20202000u;
   *count = 1;
   return;
 }
#endif

 *count = 0;
}

static bool
parse_private_use_subtag (const char     *private_use_subtag,
		  unsigned int   *count,
		  hb_tag_t       *tags,
		  const char     *prefix,
		  unsigned char (*normalize) (unsigned char))
{
#ifdef HB_NO_LANGUAGE_PRIVATE_SUBTAG
 return false;
#endif

 if (!(private_use_subtag && count && tags && *count)) return false;

 const char *s = strstr (private_use_subtag, prefix);
 if (!s) return false;

 char tag[4];
 int i;
 s += strlen (prefix);
 if (s[0] == '-') {
   s += 1;
   char c;
   for (i = 0; i < 8 && ISHEX (s[i]); i++)
   {
     c = FROMHEX (s[i]);
     if (i % 2 == 0)
tag[i / 2] = c << 4;
     else
tag[i / 2] += c;
   }
   if (i != 8) return false;
 } else {
   for (i = 0; i < 4 && ISALNUM (s[i]); i++)
     tag[i] = normalize (s[i]);
   if (!i) return false;

   for (; i < 4; i++)
     tag[i] = ' ';
 }
 tags[0] = HB_TAG (tag[0], tag[1], tag[2], tag[3]);
 if ((tags[0] & 0xDFDFDFDF) == HB_OT_TAG_DEFAULT_SCRIPT)
   tags[0] ^= ~0xDFDFDFDF;
 *count = 1;
 return true;
}

/**
* hb_ot_tags_from_script_and_language:
* @script: an #hb_script_t to convert.
* @language: (nullable): an #hb_language_t to convert.
* @script_count: (inout) (optional): maximum number of script tags to retrieve (IN)
* and actual number of script tags retrieved (OUT)
* @script_tags: (out) (optional): array of size at least @script_count to store the
* script tag results
* @language_count: (inout) (optional): maximum number of language tags to retrieve
* (IN) and actual number of language tags retrieved (OUT)
* @language_tags: (out) (optional): array of size at least @language_count to store
* the language tag results
*
* Converts an #hb_script_t and an #hb_language_t to script and language tags.
*
* Since: 2.0.0
**/
void
hb_ot_tags_from_script_and_language (hb_script_t   script,
			     hb_language_t language,
			     unsigned int *script_count /* IN/OUT */,
			     hb_tag_t     *script_tags /* OUT */,
			     unsigned int *language_count /* IN/OUT */,
			     hb_tag_t     *language_tags /* OUT */)
{
 bool needs_script = true;

 if (language == HB_LANGUAGE_INVALID)
 {
   if (language_count && language_tags && *language_count)
     *language_count = 0;
 }
 else
 {
   const char *lang_str, *s, *limit, *private_use_subtag;
   bool needs_language;

   lang_str = hb_language_to_string (language);
   limit = nullptr;
   private_use_subtag = nullptr;
   if (lang_str[0] == 'x' && lang_str[1] == '-')
   {
     private_use_subtag = lang_str;
   } else {
     for (s = lang_str + 1; *s; s++)
     {
if (s[-1] == '-' && s[1] == '-')
{
  if (s[0] == 'x')
  {
    private_use_subtag = s;
    if (!limit)
      limit = s - 1;
    break;
  } else if (!limit)
  {
    limit = s - 1;
  }
}
     }
     if (!limit)
limit = s;
   }

   needs_script = !parse_private_use_subtag (private_use_subtag, script_count, script_tags, "-hbsc", TOLOWER);
   needs_language = !parse_private_use_subtag (private_use_subtag, language_count, language_tags, "-hbot", TOUPPER);

   if (needs_language && language_count && language_tags && *language_count)
     hb_ot_tags_from_language (lang_str, limit, language_count, language_tags);
 }

 if (needs_script && script_count && script_tags && *script_count)
   hb_ot_all_tags_from_script (script, script_count, script_tags);
}

/**
* hb_ot_tag_to_language:
* @tag: an language tag
*
* Converts a language tag to an #hb_language_t.
*
* Return value: (transfer none) (nullable):
* The #hb_language_t corresponding to @tag.
*
* Since: 0.9.2
**/
hb_language_t
hb_ot_tag_to_language (hb_tag_t tag)
{
 unsigned int i;

 if (tag == HB_OT_TAG_DEFAULT_LANGUAGE)
   return nullptr;

#ifndef HB_NO_LANGUAGE_LONG
 {
   hb_language_t disambiguated_tag = hb_ot_ambiguous_tag_to_language (tag);
   if (disambiguated_tag != HB_LANGUAGE_INVALID)
     return disambiguated_tag;
 }
#endif

 char buf[4];
 for (i = 0; i < ARRAY_LENGTH (ot_languages2); i++)
   if (ot_languages2[i].tag == tag)
   {
     hb_tag_to_string (ot_languages2[i].language, buf);
     return hb_language_from_string (buf, 2);
   }
#ifndef HB_NO_LANGUAGE_LONG
 for (i = 0; i < ARRAY_LENGTH (ot_languages3); i++)
   if (ot_languages3[i].tag == tag)
   {
     hb_tag_to_string (ot_languages3[i].language, buf);
     return hb_language_from_string (buf, 3);
   }
#endif

 /* Return a custom language in the form of "x-hbot-AABBCCDD".
  * If it's three letters long, also guess it's ISO 639-3 and lower-case and
  * prepend it (if it's not a registered tag, the private use subtags will
  * ensure that calling hb_ot_tag_from_language on the result will still return
  * the same tag as the original tag).
  */
 {
   char buf[20];
   char *str = buf;
   if (ISALPHA (tag >> 24)
&& ISALPHA ((tag >> 16) & 0xFF)
&& ISALPHA ((tag >> 8) & 0xFF)
&& (tag & 0xFF) == ' ')
   {
     buf[0] = TOLOWER (tag >> 24);
     buf[1] = TOLOWER ((tag >> 16) & 0xFF);
     buf[2] = TOLOWER ((tag >> 8) & 0xFF);
     buf[3] = '-';
     str += 4;
   }
   snprintf (str, 16, "x-hbot-%08" PRIx32, tag);
   return hb_language_from_string (&*buf, -1);
 }
}

/**
* hb_ot_tags_to_script_and_language:
* @script_tag: a script tag
* @language_tag: a language tag
* @script: (out) (optional): the #hb_script_t corresponding to @script_tag.
* @language: (out) (optional): the #hb_language_t corresponding to @script_tag and
* @language_tag.
*
* Converts a script tag and a language tag to an #hb_script_t and an
* #hb_language_t.
*
* Since: 2.0.0
**/
void
hb_ot_tags_to_script_and_language (hb_tag_t       script_tag,
			   hb_tag_t       language_tag,
			   hb_script_t   *script /* OUT */,
			   hb_language_t *language /* OUT */)
{
 hb_script_t script_out = hb_ot_tag_to_script (script_tag);
 if (script)
   *script = script_out;
 if (language)
 {
   unsigned int script_count = 1;
   hb_tag_t primary_script_tag[1];
   hb_ot_tags_from_script_and_language (script_out,
				 HB_LANGUAGE_INVALID,
				 &script_count,
				 primary_script_tag,
				 nullptr, nullptr);
   *language = hb_ot_tag_to_language (language_tag);
   if (script_count == 0 || primary_script_tag[0] != script_tag)
   {
     unsigned char *buf;
     const char *lang_str = hb_language_to_string (*language);
     size_t len = strlen (lang_str);
     buf = (unsigned char *) hb_malloc (len + 16);
     if (unlikely (!buf))
     {
*language = nullptr;
     }
     else
     {
int shift;
hb_memcpy (buf, lang_str, len);
if (lang_str[0] != 'x' || lang_str[1] != '-') {
  buf[len++] = '-';
  buf[len++] = 'x';
}
buf[len++] = '-';
buf[len++] = 'h';
buf[len++] = 'b';
buf[len++] = 's';
buf[len++] = 'c';
buf[len++] = '-';
for (shift = 28; shift >= 0; shift -= 4)
  buf[len++] = TOHEX (script_tag >> shift);
*language = hb_language_from_string ((char *) buf, len);
hb_free (buf);
     }
   }
 }
}

#ifdef MAIN
static inline void
test_langs_sorted ()
{
 for (unsigned int i = 1; i < ARRAY_LENGTH (ot_languages2); i++)
 {
   int c = ot_languages2[i].cmp (&ot_languages2[i - 1]);
   if (c > 0)
   {
     fprintf (stderr, "ot_languages2 not sorted at index %u: %08x %d %08x\n",
       i, ot_languages2[i-1].language, c, ot_languages2[i].language);
     abort();
   }
 }
#ifndef HB_NO_LANGUAGE_LONG
 for (unsigned int i = 1; i < ARRAY_LENGTH (ot_languages3); i++)
 {
   int c = ot_languages3[i].cmp (&ot_languages3[i - 1]);
   if (c > 0)
   {
     fprintf (stderr, "ot_languages3 not sorted at index %u: %08x %d %08x\n",
       i, ot_languages3[i-1].language, c, ot_languages3[i].language);
     abort();
   }
 }
#endif
}

int
main ()
{
 test_langs_sorted ();
 return 0;
}

#endif


#endif