Line data Source code
1 : /*
2 : * Copyright © 2009,2010 Red Hat, Inc.
3 : * Copyright © 2011,2012 Google, Inc.
4 : *
5 : * This is part of HarfBuzz, a text shaping library.
6 : *
7 : * Permission is hereby granted, without written agreement and without
8 : * license or royalty fees, to use, copy, modify, and distribute this
9 : * software and its documentation for any purpose, provided that the
10 : * above copyright notice and the following two paragraphs appear in
11 : * all copies of this software.
12 : *
13 : * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
14 : * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
15 : * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
16 : * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
17 : * DAMAGE.
18 : *
19 : * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
20 : * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21 : * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
22 : * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
23 : * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
24 : *
25 : * Red Hat Author(s): Behdad Esfahbod
26 : * Google Author(s): Behdad Esfahbod
27 : */
28 :
29 : #include "hb-private.hh"
30 :
31 : #include "hb-mutex-private.hh"
32 : #include "hb-object-private.hh"
33 :
34 : #include <locale.h>
35 :
36 :
37 : /* hb_options_t */
38 :
39 : hb_options_union_t _hb_options;
40 :
41 : void
42 0 : _hb_options_init (void)
43 : {
44 : hb_options_union_t u;
45 0 : u.i = 0;
46 0 : u.opts.initialized = 1;
47 :
48 0 : char *c = getenv ("HB_OPTIONS");
49 0 : u.opts.uniscribe_bug_compatible = c && strstr (c, "uniscribe-bug-compatible");
50 :
51 : /* This is idempotent and threadsafe. */
52 0 : _hb_options = u;
53 0 : }
54 :
55 :
56 : /* hb_tag_t */
57 :
58 : /**
59 : * hb_tag_from_string:
60 : * @str: (array length=len) (element-type uint8_t):
61 : * @len:
62 : *
63 : *
64 : *
65 : * Return value:
66 : *
67 : * Since: 0.9.2
68 : **/
69 : hb_tag_t
70 0 : hb_tag_from_string (const char *str, int len)
71 : {
72 : char tag[4];
73 : unsigned int i;
74 :
75 0 : if (!str || !len || !*str)
76 0 : return HB_TAG_NONE;
77 :
78 0 : if (len < 0 || len > 4)
79 0 : len = 4;
80 0 : for (i = 0; i < (unsigned) len && str[i]; i++)
81 0 : tag[i] = str[i];
82 0 : for (; i < 4; i++)
83 0 : tag[i] = ' ';
84 :
85 0 : return HB_TAG_CHAR4 (tag);
86 : }
87 :
88 : /**
89 : * hb_tag_to_string:
90 : * @tag:
91 : * @buf: (out caller-allocates) (array fixed-size=4) (element-type uint8_t):
92 : *
93 : *
94 : *
95 : * Since: 0.9.5
96 : **/
97 : void
98 0 : hb_tag_to_string (hb_tag_t tag, char *buf)
99 : {
100 0 : buf[0] = (char) (uint8_t) (tag >> 24);
101 0 : buf[1] = (char) (uint8_t) (tag >> 16);
102 0 : buf[2] = (char) (uint8_t) (tag >> 8);
103 0 : buf[3] = (char) (uint8_t) (tag >> 0);
104 0 : }
105 :
106 :
107 : /* hb_direction_t */
108 :
109 : const char direction_strings[][4] = {
110 : "ltr",
111 : "rtl",
112 : "ttb",
113 : "btt"
114 : };
115 :
116 : /**
117 : * hb_direction_from_string:
118 : * @str: (array length=len) (element-type uint8_t):
119 : * @len:
120 : *
121 : *
122 : *
123 : * Return value:
124 : *
125 : * Since: 0.9.2
126 : **/
127 : hb_direction_t
128 0 : hb_direction_from_string (const char *str, int len)
129 : {
130 0 : if (unlikely (!str || !len || !*str))
131 0 : return HB_DIRECTION_INVALID;
132 :
133 : /* Lets match loosely: just match the first letter, such that
134 : * all of "ltr", "left-to-right", etc work!
135 : */
136 0 : char c = TOLOWER (str[0]);
137 0 : for (unsigned int i = 0; i < ARRAY_LENGTH (direction_strings); i++)
138 0 : if (c == direction_strings[i][0])
139 0 : return (hb_direction_t) (HB_DIRECTION_LTR + i);
140 :
141 0 : return HB_DIRECTION_INVALID;
142 : }
143 :
144 : /**
145 : * hb_direction_to_string:
146 : * @direction:
147 : *
148 : *
149 : *
150 : * Return value: (transfer none):
151 : *
152 : * Since: 0.9.2
153 : **/
154 : const char *
155 0 : hb_direction_to_string (hb_direction_t direction)
156 : {
157 0 : if (likely ((unsigned int) (direction - HB_DIRECTION_LTR)
158 : < ARRAY_LENGTH (direction_strings)))
159 0 : return direction_strings[direction - HB_DIRECTION_LTR];
160 :
161 0 : return "invalid";
162 : }
163 :
164 :
165 : /* hb_language_t */
166 :
167 : struct hb_language_impl_t {
168 : const char s[1];
169 : };
170 :
171 : static const char canon_map[256] = {
172 : 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
173 : 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
174 : 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, '-', 0, 0,
175 : '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 0, 0, 0, 0, 0, 0,
176 : '-', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
177 : 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 0, 0, 0, 0, '-',
178 : 0, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
179 : 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 0, 0, 0, 0, 0
180 : };
181 :
182 : static bool
183 0 : lang_equal (hb_language_t v1,
184 : const void *v2)
185 : {
186 0 : const unsigned char *p1 = (const unsigned char *) v1;
187 0 : const unsigned char *p2 = (const unsigned char *) v2;
188 :
189 0 : while (*p1 && *p1 == canon_map[*p2]) {
190 0 : p1++;
191 0 : p2++;
192 : }
193 :
194 0 : return *p1 == canon_map[*p2];
195 : }
196 :
197 : #if 0
198 : static unsigned int
199 : lang_hash (const void *key)
200 : {
201 : const unsigned char *p = key;
202 : unsigned int h = 0;
203 : while (canon_map[*p])
204 : {
205 : h = (h << 5) - h + canon_map[*p];
206 : p++;
207 : }
208 :
209 : return h;
210 : }
211 : #endif
212 :
213 :
214 : struct hb_language_item_t {
215 :
216 : struct hb_language_item_t *next;
217 : hb_language_t lang;
218 :
219 0 : inline bool operator == (const char *s) const {
220 0 : return lang_equal (lang, s);
221 : }
222 :
223 0 : inline hb_language_item_t & operator = (const char *s) {
224 0 : lang = (hb_language_t) strdup (s);
225 0 : for (unsigned char *p = (unsigned char *) lang; *p; p++)
226 0 : *p = canon_map[*p];
227 :
228 0 : return *this;
229 : }
230 :
231 0 : void finish (void) { free ((void *) lang); }
232 : };
233 :
234 :
235 : /* Thread-safe lock-free language list */
236 :
237 : static hb_language_item_t *langs;
238 :
239 : #ifdef HB_USE_ATEXIT
240 : static
241 : void free_langs (void)
242 : {
243 : while (langs) {
244 : hb_language_item_t *next = langs->next;
245 : langs->finish ();
246 : free (langs);
247 : langs = next;
248 : }
249 : }
250 : #endif
251 :
252 : static hb_language_item_t *
253 0 : lang_find_or_insert (const char *key)
254 : {
255 : retry:
256 0 : hb_language_item_t *first_lang = (hb_language_item_t *) hb_atomic_ptr_get (&langs);
257 :
258 0 : for (hb_language_item_t *lang = first_lang; lang; lang = lang->next)
259 0 : if (*lang == key)
260 0 : return lang;
261 :
262 : /* Not found; allocate one. */
263 0 : hb_language_item_t *lang = (hb_language_item_t *) calloc (1, sizeof (hb_language_item_t));
264 0 : if (unlikely (!lang))
265 0 : return NULL;
266 0 : lang->next = first_lang;
267 0 : *lang = key;
268 :
269 0 : if (!hb_atomic_ptr_cmpexch (&langs, first_lang, lang)) {
270 0 : lang->finish ();
271 0 : free (lang);
272 0 : goto retry;
273 : }
274 :
275 : #ifdef HB_USE_ATEXIT
276 : if (!first_lang)
277 : atexit (free_langs); /* First person registers atexit() callback. */
278 : #endif
279 :
280 0 : return lang;
281 : }
282 :
283 :
284 : /**
285 : * hb_language_from_string:
286 : * @str: (array length=len) (element-type uint8_t): a string representing
287 : * ISO 639 language code
288 : * @len: length of the @str, or -1 if it is %NULL-terminated.
289 : *
290 : * Converts @str representing an ISO 639 language code to the corresponding
291 : * #hb_language_t.
292 : *
293 : * Return value: (transfer none):
294 : * The #hb_language_t corresponding to the ISO 639 language code.
295 : *
296 : * Since: 0.9.2
297 : **/
298 : hb_language_t
299 0 : hb_language_from_string (const char *str, int len)
300 : {
301 0 : if (!str || !len || !*str)
302 0 : return HB_LANGUAGE_INVALID;
303 :
304 0 : hb_language_item_t *item = NULL;
305 0 : if (len >= 0)
306 : {
307 : /* NUL-terminate it. */
308 : char strbuf[64];
309 0 : len = MIN (len, (int) sizeof (strbuf) - 1);
310 0 : memcpy (strbuf, str, len);
311 0 : strbuf[len] = '\0';
312 0 : item = lang_find_or_insert (strbuf);
313 : }
314 : else
315 0 : item = lang_find_or_insert (str);
316 :
317 0 : return likely (item) ? item->lang : HB_LANGUAGE_INVALID;
318 : }
319 :
320 : /**
321 : * hb_language_to_string:
322 : * @language: an #hb_language_t to convert.
323 : *
324 : * See hb_language_from_string().
325 : *
326 : * Return value: (transfer none):
327 : * A %NULL-terminated string representing the @language. Must not be freed by
328 : * the caller.
329 : *
330 : * Since: 0.9.2
331 : **/
332 : const char *
333 0 : hb_language_to_string (hb_language_t language)
334 : {
335 : /* This is actually NULL-safe! */
336 0 : return language->s;
337 : }
338 :
339 : /**
340 : * hb_language_get_default:
341 : *
342 : *
343 : *
344 : * Return value: (transfer none):
345 : *
346 : * Since: 0.9.2
347 : **/
348 : hb_language_t
349 0 : hb_language_get_default (void)
350 : {
351 : static hb_language_t default_language = HB_LANGUAGE_INVALID;
352 :
353 0 : hb_language_t language = (hb_language_t) hb_atomic_ptr_get (&default_language);
354 0 : if (unlikely (language == HB_LANGUAGE_INVALID)) {
355 0 : language = hb_language_from_string (setlocale (LC_CTYPE, NULL), -1);
356 0 : (void) hb_atomic_ptr_cmpexch (&default_language, HB_LANGUAGE_INVALID, language);
357 : }
358 :
359 0 : return default_language;
360 : }
361 :
362 :
363 : /* hb_script_t */
364 :
365 : /**
366 : * hb_script_from_iso15924_tag:
367 : * @tag: an #hb_tag_t representing an ISO 15924 tag.
368 : *
369 : * Converts an ISO 15924 script tag to a corresponding #hb_script_t.
370 : *
371 : * Return value:
372 : * An #hb_script_t corresponding to the ISO 15924 tag.
373 : *
374 : * Since: 0.9.2
375 : **/
376 : hb_script_t
377 0 : hb_script_from_iso15924_tag (hb_tag_t tag)
378 : {
379 0 : if (unlikely (tag == HB_TAG_NONE))
380 0 : return HB_SCRIPT_INVALID;
381 :
382 : /* Be lenient, adjust case (one capital letter followed by three small letters) */
383 0 : tag = (tag & 0xDFDFDFDFu) | 0x00202020u;
384 :
385 0 : switch (tag) {
386 :
387 : /* These graduated from the 'Q' private-area codes, but
388 : * the old code is still aliased by Unicode, and the Qaai
389 : * one in use by ICU. */
390 0 : case HB_TAG('Q','a','a','i'): return HB_SCRIPT_INHERITED;
391 0 : case HB_TAG('Q','a','a','c'): return HB_SCRIPT_COPTIC;
392 :
393 : /* Script variants from http://unicode.org/iso15924/ */
394 0 : case HB_TAG('C','y','r','s'): return HB_SCRIPT_CYRILLIC;
395 0 : case HB_TAG('L','a','t','f'): return HB_SCRIPT_LATIN;
396 0 : case HB_TAG('L','a','t','g'): return HB_SCRIPT_LATIN;
397 0 : case HB_TAG('S','y','r','e'): return HB_SCRIPT_SYRIAC;
398 0 : case HB_TAG('S','y','r','j'): return HB_SCRIPT_SYRIAC;
399 0 : case HB_TAG('S','y','r','n'): return HB_SCRIPT_SYRIAC;
400 : }
401 :
402 : /* If it looks right, just use the tag as a script */
403 0 : if (((uint32_t) tag & 0xE0E0E0E0u) == 0x40606060u)
404 0 : return (hb_script_t) tag;
405 :
406 : /* Otherwise, return unknown */
407 0 : return HB_SCRIPT_UNKNOWN;
408 : }
409 :
410 : /**
411 : * hb_script_from_string:
412 : * @str: (array length=len) (element-type uint8_t): a string representing an
413 : * ISO 15924 tag.
414 : * @len: length of the @str, or -1 if it is %NULL-terminated.
415 : *
416 : * Converts a string @str representing an ISO 15924 script tag to a
417 : * corresponding #hb_script_t. Shorthand for hb_tag_from_string() then
418 : * hb_script_from_iso15924_tag().
419 : *
420 : * Return value:
421 : * An #hb_script_t corresponding to the ISO 15924 tag.
422 : *
423 : * Since: 0.9.2
424 : **/
425 : hb_script_t
426 0 : hb_script_from_string (const char *str, int len)
427 : {
428 0 : return hb_script_from_iso15924_tag (hb_tag_from_string (str, len));
429 : }
430 :
431 : /**
432 : * hb_script_to_iso15924_tag:
433 : * @script: an #hb_script_ to convert.
434 : *
435 : * See hb_script_from_iso15924_tag().
436 : *
437 : * Return value:
438 : * An #hb_tag_t representing an ISO 15924 script tag.
439 : *
440 : * Since: 0.9.2
441 : **/
442 : hb_tag_t
443 0 : hb_script_to_iso15924_tag (hb_script_t script)
444 : {
445 0 : return (hb_tag_t) script;
446 : }
447 :
448 : /**
449 : * hb_script_get_horizontal_direction:
450 : * @script:
451 : *
452 : *
453 : *
454 : * Return value:
455 : *
456 : * Since: 0.9.2
457 : **/
458 : hb_direction_t
459 34 : hb_script_get_horizontal_direction (hb_script_t script)
460 : {
461 : /* http://goo.gl/x9ilM */
462 34 : switch ((hb_tag_t) script)
463 : {
464 : /* Unicode-1.1 additions */
465 : case HB_SCRIPT_ARABIC:
466 : case HB_SCRIPT_HEBREW:
467 :
468 : /* Unicode-3.0 additions */
469 : case HB_SCRIPT_SYRIAC:
470 : case HB_SCRIPT_THAANA:
471 :
472 : /* Unicode-4.0 additions */
473 : case HB_SCRIPT_CYPRIOT:
474 :
475 : /* Unicode-4.1 additions */
476 : case HB_SCRIPT_KHAROSHTHI:
477 :
478 : /* Unicode-5.0 additions */
479 : case HB_SCRIPT_PHOENICIAN:
480 : case HB_SCRIPT_NKO:
481 :
482 : /* Unicode-5.1 additions */
483 : case HB_SCRIPT_LYDIAN:
484 :
485 : /* Unicode-5.2 additions */
486 : case HB_SCRIPT_AVESTAN:
487 : case HB_SCRIPT_IMPERIAL_ARAMAIC:
488 : case HB_SCRIPT_INSCRIPTIONAL_PAHLAVI:
489 : case HB_SCRIPT_INSCRIPTIONAL_PARTHIAN:
490 : case HB_SCRIPT_OLD_SOUTH_ARABIAN:
491 : case HB_SCRIPT_OLD_TURKIC:
492 : case HB_SCRIPT_SAMARITAN:
493 :
494 : /* Unicode-6.0 additions */
495 : case HB_SCRIPT_MANDAIC:
496 :
497 : /* Unicode-6.1 additions */
498 : case HB_SCRIPT_MEROITIC_CURSIVE:
499 : case HB_SCRIPT_MEROITIC_HIEROGLYPHS:
500 :
501 : /* Unicode-7.0 additions */
502 : case HB_SCRIPT_MANICHAEAN:
503 : case HB_SCRIPT_MENDE_KIKAKUI:
504 : case HB_SCRIPT_NABATAEAN:
505 : case HB_SCRIPT_OLD_NORTH_ARABIAN:
506 : case HB_SCRIPT_PALMYRENE:
507 : case HB_SCRIPT_PSALTER_PAHLAVI:
508 :
509 : /* Unicode-8.0 additions */
510 : case HB_SCRIPT_OLD_HUNGARIAN:
511 :
512 : /* Unicode-9.0 additions */
513 : case HB_SCRIPT_ADLAM:
514 :
515 0 : return HB_DIRECTION_RTL;
516 : }
517 :
518 34 : return HB_DIRECTION_LTR;
519 : }
520 :
521 :
522 : /* hb_user_data_array_t */
523 :
524 : bool
525 0 : hb_user_data_array_t::set (hb_user_data_key_t *key,
526 : void * data,
527 : hb_destroy_func_t destroy,
528 : hb_bool_t replace)
529 : {
530 0 : if (!key)
531 0 : return false;
532 :
533 0 : if (replace) {
534 0 : if (!data && !destroy) {
535 0 : items.remove (key, lock);
536 0 : return true;
537 : }
538 : }
539 0 : hb_user_data_item_t item = {key, data, destroy};
540 0 : bool ret = !!items.replace_or_insert (item, lock, (bool) replace);
541 :
542 0 : return ret;
543 : }
544 :
545 : void *
546 0 : hb_user_data_array_t::get (hb_user_data_key_t *key)
547 : {
548 0 : hb_user_data_item_t item = {NULL, NULL, NULL};
549 :
550 0 : return items.find (key, &item, lock) ? item.data : NULL;
551 : }
552 :
553 :
554 : /* hb_version */
555 :
556 : /**
557 : * hb_version:
558 : * @major: (out): Library major version component.
559 : * @minor: (out): Library minor version component.
560 : * @micro: (out): Library micro version component.
561 : *
562 : * Returns library version as three integer components.
563 : *
564 : * Since: 0.9.2
565 : **/
566 : void
567 0 : hb_version (unsigned int *major,
568 : unsigned int *minor,
569 : unsigned int *micro)
570 : {
571 0 : *major = HB_VERSION_MAJOR;
572 0 : *minor = HB_VERSION_MINOR;
573 0 : *micro = HB_VERSION_MICRO;
574 0 : }
575 :
576 : /**
577 : * hb_version_string:
578 : *
579 : * Returns library version as a string with three components.
580 : *
581 : * Return value: library version string.
582 : *
583 : * Since: 0.9.2
584 : **/
585 : const char *
586 0 : hb_version_string (void)
587 : {
588 0 : return HB_VERSION_STRING;
589 : }
590 :
591 : /**
592 : * hb_version_atleast:
593 : * @major:
594 : * @minor:
595 : * @micro:
596 : *
597 : *
598 : *
599 : * Return value:
600 : *
601 : * Since: 0.9.30
602 : **/
603 : hb_bool_t
604 0 : hb_version_atleast (unsigned int major,
605 : unsigned int minor,
606 : unsigned int micro)
607 : {
608 0 : return HB_VERSION_ATLEAST (major, minor, micro);
609 : }
610 :
611 :
612 :
613 : /* hb_feature_t and hb_variation_t */
614 :
615 : static bool
616 0 : parse_space (const char **pp, const char *end)
617 : {
618 0 : while (*pp < end && ISSPACE (**pp))
619 0 : (*pp)++;
620 0 : return true;
621 : }
622 :
623 : static bool
624 0 : parse_char (const char **pp, const char *end, char c)
625 : {
626 0 : parse_space (pp, end);
627 :
628 0 : if (*pp == end || **pp != c)
629 0 : return false;
630 :
631 0 : (*pp)++;
632 0 : return true;
633 : }
634 :
635 : static bool
636 0 : parse_uint (const char **pp, const char *end, unsigned int *pv)
637 : {
638 : char buf[32];
639 0 : unsigned int len = MIN (ARRAY_LENGTH (buf) - 1, (unsigned int) (end - *pp));
640 0 : strncpy (buf, *pp, len);
641 0 : buf[len] = '\0';
642 :
643 0 : char *p = buf;
644 0 : char *pend = p;
645 : unsigned int v;
646 :
647 : /* Intentionally use strtol instead of strtoul, such that
648 : * -1 turns into "big number"... */
649 0 : errno = 0;
650 0 : v = strtol (p, &pend, 0);
651 0 : if (errno || p == pend)
652 0 : return false;
653 :
654 0 : *pv = v;
655 0 : *pp += pend - p;
656 0 : return true;
657 : }
658 :
659 : static bool
660 0 : parse_float (const char **pp, const char *end, float *pv)
661 : {
662 : char buf[32];
663 0 : unsigned int len = MIN (ARRAY_LENGTH (buf) - 1, (unsigned int) (end - *pp));
664 0 : strncpy (buf, *pp, len);
665 0 : buf[len] = '\0';
666 :
667 0 : char *p = buf;
668 0 : char *pend = p;
669 : float v;
670 :
671 0 : errno = 0;
672 0 : v = strtod (p, &pend);
673 0 : if (errno || p == pend)
674 0 : return false;
675 :
676 0 : *pv = v;
677 0 : *pp += pend - p;
678 0 : return true;
679 : }
680 :
681 : static bool
682 0 : parse_bool (const char **pp, const char *end, unsigned int *pv)
683 : {
684 0 : parse_space (pp, end);
685 :
686 0 : const char *p = *pp;
687 0 : while (*pp < end && ISALPHA(**pp))
688 0 : (*pp)++;
689 :
690 : /* CSS allows on/off as aliases 1/0. */
691 0 : if (*pp - p == 2 || 0 == strncmp (p, "on", 2))
692 0 : *pv = 1;
693 0 : else if (*pp - p == 3 || 0 == strncmp (p, "off", 2))
694 0 : *pv = 0;
695 : else
696 0 : return false;
697 :
698 0 : return true;
699 : }
700 :
701 : /* hb_feature_t */
702 :
703 : static bool
704 0 : parse_feature_value_prefix (const char **pp, const char *end, hb_feature_t *feature)
705 : {
706 0 : if (parse_char (pp, end, '-'))
707 0 : feature->value = 0;
708 : else {
709 0 : parse_char (pp, end, '+');
710 0 : feature->value = 1;
711 : }
712 :
713 0 : return true;
714 : }
715 :
716 : static bool
717 0 : parse_tag (const char **pp, const char *end, hb_tag_t *tag)
718 : {
719 0 : parse_space (pp, end);
720 :
721 0 : char quote = 0;
722 :
723 0 : if (*pp < end && (**pp == '\'' || **pp == '"'))
724 : {
725 0 : quote = **pp;
726 0 : (*pp)++;
727 : }
728 :
729 0 : const char *p = *pp;
730 0 : while (*pp < end && ISALNUM(**pp))
731 0 : (*pp)++;
732 :
733 0 : if (p == *pp || *pp - p > 4)
734 0 : return false;
735 :
736 0 : *tag = hb_tag_from_string (p, *pp - p);
737 :
738 0 : if (quote)
739 : {
740 : /* CSS expects exactly four bytes. And we only allow quotations for
741 : * CSS compatibility. So, enforce the length. */
742 0 : if (*pp - p != 4)
743 0 : return false;
744 0 : if (*pp == end || **pp != quote)
745 0 : return false;
746 0 : (*pp)++;
747 : }
748 :
749 0 : return true;
750 : }
751 :
752 : static bool
753 0 : parse_feature_indices (const char **pp, const char *end, hb_feature_t *feature)
754 : {
755 0 : parse_space (pp, end);
756 :
757 : bool has_start;
758 :
759 0 : feature->start = 0;
760 0 : feature->end = (unsigned int) -1;
761 :
762 0 : if (!parse_char (pp, end, '['))
763 0 : return true;
764 :
765 0 : has_start = parse_uint (pp, end, &feature->start);
766 :
767 0 : if (parse_char (pp, end, ':')) {
768 0 : parse_uint (pp, end, &feature->end);
769 : } else {
770 0 : if (has_start)
771 0 : feature->end = feature->start + 1;
772 : }
773 :
774 0 : return parse_char (pp, end, ']');
775 : }
776 :
777 : static bool
778 0 : parse_feature_value_postfix (const char **pp, const char *end, hb_feature_t *feature)
779 : {
780 0 : bool had_equal = parse_char (pp, end, '=');
781 0 : bool had_value = parse_uint (pp, end, &feature->value) ||
782 0 : parse_bool (pp, end, &feature->value);
783 : /* CSS doesn't use equal-sign between tag and value.
784 : * If there was an equal-sign, then there *must* be a value.
785 : * A value without an eqaul-sign is ok, but not required. */
786 0 : return !had_equal || had_value;
787 : }
788 :
789 : static bool
790 0 : parse_one_feature (const char **pp, const char *end, hb_feature_t *feature)
791 : {
792 0 : return parse_feature_value_prefix (pp, end, feature) &&
793 0 : parse_tag (pp, end, &feature->tag) &&
794 0 : parse_feature_indices (pp, end, feature) &&
795 0 : parse_feature_value_postfix (pp, end, feature) &&
796 0 : parse_space (pp, end) &&
797 0 : *pp == end;
798 : }
799 :
800 : /**
801 : * hb_feature_from_string:
802 : * @str: (array length=len) (element-type uint8_t): a string to parse
803 : * @len: length of @str, or -1 if string is %NULL terminated
804 : * @feature: (out): the #hb_feature_t to initialize with the parsed values
805 : *
806 : * Parses a string into a #hb_feature_t.
807 : *
808 : * TODO: document the syntax here.
809 : *
810 : * Return value:
811 : * %true if @str is successfully parsed, %false otherwise.
812 : *
813 : * Since: 0.9.5
814 : **/
815 : hb_bool_t
816 0 : hb_feature_from_string (const char *str, int len,
817 : hb_feature_t *feature)
818 : {
819 : hb_feature_t feat;
820 :
821 0 : if (len < 0)
822 0 : len = strlen (str);
823 :
824 0 : if (likely (parse_one_feature (&str, str + len, &feat)))
825 : {
826 0 : if (feature)
827 0 : *feature = feat;
828 0 : return true;
829 : }
830 :
831 0 : if (feature)
832 0 : memset (feature, 0, sizeof (*feature));
833 0 : return false;
834 : }
835 :
836 : /**
837 : * hb_feature_to_string:
838 : * @feature: an #hb_feature_t to convert
839 : * @buf: (array length=size) (out): output string
840 : * @size: the allocated size of @buf
841 : *
842 : * Converts a #hb_feature_t into a %NULL-terminated string in the format
843 : * understood by hb_feature_from_string(). The client in responsible for
844 : * allocating big enough size for @buf, 128 bytes is more than enough.
845 : *
846 : * Since: 0.9.5
847 : **/
848 : void
849 0 : hb_feature_to_string (hb_feature_t *feature,
850 : char *buf, unsigned int size)
851 : {
852 0 : if (unlikely (!size)) return;
853 :
854 : char s[128];
855 0 : unsigned int len = 0;
856 0 : if (feature->value == 0)
857 0 : s[len++] = '-';
858 0 : hb_tag_to_string (feature->tag, s + len);
859 0 : len += 4;
860 0 : while (len && s[len - 1] == ' ')
861 0 : len--;
862 0 : if (feature->start != 0 || feature->end != (unsigned int) -1)
863 : {
864 0 : s[len++] = '[';
865 0 : if (feature->start)
866 0 : len += MAX (0, snprintf (s + len, ARRAY_LENGTH (s) - len, "%u", feature->start));
867 0 : if (feature->end != feature->start + 1) {
868 0 : s[len++] = ':';
869 0 : if (feature->end != (unsigned int) -1)
870 0 : len += MAX (0, snprintf (s + len, ARRAY_LENGTH (s) - len, "%u", feature->end));
871 : }
872 0 : s[len++] = ']';
873 : }
874 0 : if (feature->value > 1)
875 : {
876 0 : s[len++] = '=';
877 0 : len += MAX (0, snprintf (s + len, ARRAY_LENGTH (s) - len, "%u", feature->value));
878 : }
879 0 : assert (len < ARRAY_LENGTH (s));
880 0 : len = MIN (len, size - 1);
881 0 : memcpy (buf, s, len);
882 0 : buf[len] = '\0';
883 : }
884 :
885 : /* hb_variation_t */
886 :
887 : static bool
888 0 : parse_variation_value (const char **pp, const char *end, hb_variation_t *variation)
889 : {
890 0 : parse_char (pp, end, '='); /* Optional. */
891 0 : return parse_float (pp, end, &variation->value);
892 : }
893 :
894 : static bool
895 0 : parse_one_variation (const char **pp, const char *end, hb_variation_t *variation)
896 : {
897 0 : return parse_tag (pp, end, &variation->tag) &&
898 0 : parse_variation_value (pp, end, variation) &&
899 0 : parse_space (pp, end) &&
900 0 : *pp == end;
901 : }
902 :
903 : /**
904 : * hb_variation_from_string:
905 : *
906 : * Since: 1.4.2
907 : */
908 : hb_bool_t
909 0 : hb_variation_from_string (const char *str, int len,
910 : hb_variation_t *variation)
911 : {
912 : hb_variation_t var;
913 :
914 0 : if (len < 0)
915 0 : len = strlen (str);
916 :
917 0 : if (likely (parse_one_variation (&str, str + len, &var)))
918 : {
919 0 : if (variation)
920 0 : *variation = var;
921 0 : return true;
922 : }
923 :
924 0 : if (variation)
925 0 : memset (variation, 0, sizeof (*variation));
926 0 : return false;
927 : }
928 :
929 : /**
930 : * hb_variation_to_string:
931 : *
932 : * Since: 1.4.2
933 : */
934 : void
935 0 : hb_variation_to_string (hb_variation_t *variation,
936 : char *buf, unsigned int size)
937 : {
938 0 : if (unlikely (!size)) return;
939 :
940 : char s[128];
941 0 : unsigned int len = 0;
942 0 : hb_tag_to_string (variation->tag, s + len);
943 0 : len += 4;
944 0 : while (len && s[len - 1] == ' ')
945 0 : len--;
946 0 : s[len++] = '=';
947 0 : len += MAX (0, snprintf (s + len, ARRAY_LENGTH (s) - len, "%g", variation->value));
948 :
949 0 : assert (len < ARRAY_LENGTH (s));
950 0 : len = MIN (len, size - 1);
951 0 : memcpy (buf, s, len);
952 0 : buf[len] = '\0';
953 : }
|
