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1 /*
2  * Copyright © 1998-2004  David Turner and Werner Lemberg
3  * Copyright © 2004,2007,2009,2010  Red Hat, Inc.
4  * Copyright © 2011,2012  Google, Inc.
5  *
6  *  This is part of HarfBuzz, a text shaping library.
7  *
8  * Permission is hereby granted, without written agreement and without
9  * license or royalty fees, to use, copy, modify, and distribute this
10  * software and its documentation for any purpose, provided that the
11  * above copyright notice and the following two paragraphs appear in
12  * all copies of this software.
13  *
14  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
15  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
16  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
17  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
18  * DAMAGE.
19  *
20  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
21  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
22  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
23  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
24  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
25  *
26  * Red Hat Author(s): Owen Taylor, Behdad Esfahbod
27  * Google Author(s): Behdad Esfahbod
28  */
29 
30 #include "hb-buffer-private.hh"
31 #include "hb-utf-private.hh"
32 
33 
34 #ifndef HB_DEBUG_BUFFER
35 #define HB_DEBUG_BUFFER (HB_DEBUG+0)
36 #endif
37 
38 /**
39  * SECTION: hb-buffer
40  * @title: Buffers
41  * @short_description: Input and output buffers
42  * @include: hb.h
43  *
44  * Buffers serve dual role in HarfBuzz; they hold the input characters that are
45  * passed hb_shape(), and after shaping they hold the output glyphs.
46  **/
47 
48 /**
49  * hb_segment_properties_equal:
50  * @a: first #hb_segment_properties_t to compare.
51  * @b: second #hb_segment_properties_t to compare.
52  *
53  * Checks the equality of two #hb_segment_properties_t's.
54  *
55  * Return value:
56  * %true if all properties of @a equal those of @b, false otherwise.
57  *
58  * Since: 0.9.7
59  **/
60 hb_bool_t
hb_segment_properties_equal(const hb_segment_properties_t * a,const hb_segment_properties_t * b)61 hb_segment_properties_equal (const hb_segment_properties_t *a,
62 			     const hb_segment_properties_t *b)
63 {
64   return a->direction == b->direction &&
65 	 a->script    == b->script    &&
66 	 a->language  == b->language  &&
67 	 a->reserved1 == b->reserved1 &&
68 	 a->reserved2 == b->reserved2;
69 
70 }
71 
72 /**
73  * hb_segment_properties_hash:
74  * @p: #hb_segment_properties_t to hash.
75  *
76  * Creates a hash representing @p.
77  *
78  * Return value:
79  * A hash of @p.
80  *
81  * Since: 0.9.7
82  **/
83 unsigned int
hb_segment_properties_hash(const hb_segment_properties_t * p)84 hb_segment_properties_hash (const hb_segment_properties_t *p)
85 {
86   return (unsigned int) p->direction ^
87 	 (unsigned int) p->script ^
88 	 (intptr_t) (p->language);
89 }
90 
91 
92 
93 /* Here is how the buffer works internally:
94  *
95  * There are two info pointers: info and out_info.  They always have
96  * the same allocated size, but different lengths.
97  *
98  * As an optimization, both info and out_info may point to the
99  * same piece of memory, which is owned by info.  This remains the
100  * case as long as out_len doesn't exceed i at any time.
101  * In that case, swap_buffers() is no-op and the glyph operations operate
102  * mostly in-place.
103  *
104  * As soon as out_info gets longer than info, out_info is moved over
105  * to an alternate buffer (which we reuse the pos buffer for!), and its
106  * current contents (out_len entries) are copied to the new place.
107  * This should all remain transparent to the user.  swap_buffers() then
108  * switches info and out_info.
109  */
110 
111 
112 
113 /* Internal API */
114 
115 bool
enlarge(unsigned int size)116 hb_buffer_t::enlarge (unsigned int size)
117 {
118   if (unlikely (in_error))
119     return false;
120   if (unlikely (size > max_len))
121   {
122     in_error = true;
123     return false;
124   }
125 
126   unsigned int new_allocated = allocated;
127   hb_glyph_position_t *new_pos = NULL;
128   hb_glyph_info_t *new_info = NULL;
129   bool separate_out = out_info != info;
130 
131   if (unlikely (_hb_unsigned_int_mul_overflows (size, sizeof (info[0]))))
132     goto done;
133 
134   while (size >= new_allocated)
135     new_allocated += (new_allocated >> 1) + 32;
136 
137   ASSERT_STATIC (sizeof (info[0]) == sizeof (pos[0]));
138   if (unlikely (_hb_unsigned_int_mul_overflows (new_allocated, sizeof (info[0]))))
139     goto done;
140 
141   new_pos = (hb_glyph_position_t *) realloc (pos, new_allocated * sizeof (pos[0]));
142   new_info = (hb_glyph_info_t *) realloc (info, new_allocated * sizeof (info[0]));
143 
144 done:
145   if (unlikely (!new_pos || !new_info))
146     in_error = true;
147 
148   if (likely (new_pos))
149     pos = new_pos;
150 
151   if (likely (new_info))
152     info = new_info;
153 
154   out_info = separate_out ? (hb_glyph_info_t *) pos : info;
155   if (likely (!in_error))
156     allocated = new_allocated;
157 
158   return likely (!in_error);
159 }
160 
161 bool
make_room_for(unsigned int num_in,unsigned int num_out)162 hb_buffer_t::make_room_for (unsigned int num_in,
163 			    unsigned int num_out)
164 {
165   if (unlikely (!ensure (out_len + num_out))) return false;
166 
167   if (out_info == info &&
168       out_len + num_out > idx + num_in)
169   {
170     assert (have_output);
171 
172     out_info = (hb_glyph_info_t *) pos;
173     memcpy (out_info, info, out_len * sizeof (out_info[0]));
174   }
175 
176   return true;
177 }
178 
179 bool
shift_forward(unsigned int count)180 hb_buffer_t::shift_forward (unsigned int count)
181 {
182   assert (have_output);
183   if (unlikely (!ensure (len + count))) return false;
184 
185   memmove (info + idx + count, info + idx, (len - idx) * sizeof (info[0]));
186   if (idx + count > len)
187   {
188     /* Under memory failure we might expose this area.  At least
189      * clean it up.  Oh well... */
190     memset (info + len, 0, (idx + count - len) * sizeof (info[0]));
191   }
192   len += count;
193   idx += count;
194 
195   return true;
196 }
197 
198 hb_buffer_t::scratch_buffer_t *
get_scratch_buffer(unsigned int * size)199 hb_buffer_t::get_scratch_buffer (unsigned int *size)
200 {
201   have_output = false;
202   have_positions = false;
203 
204   out_len = 0;
205   out_info = info;
206 
207   assert ((uintptr_t) pos % sizeof (scratch_buffer_t) == 0);
208   *size = allocated * sizeof (pos[0]) / sizeof (scratch_buffer_t);
209   return (scratch_buffer_t *) (void *) pos;
210 }
211 
212 
213 
214 /* HarfBuzz-Internal API */
215 
216 void
reset(void)217 hb_buffer_t::reset (void)
218 {
219   if (unlikely (hb_object_is_inert (this)))
220     return;
221 
222   hb_unicode_funcs_destroy (unicode);
223   unicode = hb_unicode_funcs_get_default ();
224   flags = HB_BUFFER_FLAG_DEFAULT;
225   replacement = HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT;
226 
227   clear ();
228 }
229 
230 void
clear(void)231 hb_buffer_t::clear (void)
232 {
233   if (unlikely (hb_object_is_inert (this)))
234     return;
235 
236   hb_segment_properties_t default_props = HB_SEGMENT_PROPERTIES_DEFAULT;
237   props = default_props;
238   scratch_flags = HB_BUFFER_SCRATCH_FLAG_DEFAULT;
239 
240   content_type = HB_BUFFER_CONTENT_TYPE_INVALID;
241   in_error = false;
242   have_output = false;
243   have_positions = false;
244 
245   idx = 0;
246   len = 0;
247   out_len = 0;
248   out_info = info;
249 
250   serial = 0;
251 
252   memset (context, 0, sizeof context);
253   memset (context_len, 0, sizeof context_len);
254 
255   deallocate_var_all ();
256 }
257 
258 void
add(hb_codepoint_t codepoint,unsigned int cluster)259 hb_buffer_t::add (hb_codepoint_t  codepoint,
260 		  unsigned int    cluster)
261 {
262   hb_glyph_info_t *glyph;
263 
264   if (unlikely (!ensure (len + 1))) return;
265 
266   glyph = &info[len];
267 
268   memset (glyph, 0, sizeof (*glyph));
269   glyph->codepoint = codepoint;
270   glyph->mask = 1;
271   glyph->cluster = cluster;
272 
273   len++;
274 }
275 
276 void
add_info(const hb_glyph_info_t & glyph_info)277 hb_buffer_t::add_info (const hb_glyph_info_t &glyph_info)
278 {
279   if (unlikely (!ensure (len + 1))) return;
280 
281   info[len] = glyph_info;
282 
283   len++;
284 }
285 
286 
287 void
remove_output(void)288 hb_buffer_t::remove_output (void)
289 {
290   if (unlikely (hb_object_is_inert (this)))
291     return;
292 
293   have_output = false;
294   have_positions = false;
295 
296   out_len = 0;
297   out_info = info;
298 }
299 
300 void
clear_output(void)301 hb_buffer_t::clear_output (void)
302 {
303   if (unlikely (hb_object_is_inert (this)))
304     return;
305 
306   have_output = true;
307   have_positions = false;
308 
309   out_len = 0;
310   out_info = info;
311 }
312 
313 void
clear_positions(void)314 hb_buffer_t::clear_positions (void)
315 {
316   if (unlikely (hb_object_is_inert (this)))
317     return;
318 
319   have_output = false;
320   have_positions = true;
321 
322   out_len = 0;
323   out_info = info;
324 
325   memset (pos, 0, sizeof (pos[0]) * len);
326 }
327 
328 void
swap_buffers(void)329 hb_buffer_t::swap_buffers (void)
330 {
331   if (unlikely (in_error)) return;
332 
333   assert (have_output);
334   have_output = false;
335 
336   if (out_info != info)
337   {
338     hb_glyph_info_t *tmp_string;
339     tmp_string = info;
340     info = out_info;
341     out_info = tmp_string;
342     pos = (hb_glyph_position_t *) out_info;
343   }
344 
345   unsigned int tmp;
346   tmp = len;
347   len = out_len;
348   out_len = tmp;
349 
350   idx = 0;
351 }
352 
353 
354 void
replace_glyphs(unsigned int num_in,unsigned int num_out,const uint32_t * glyph_data)355 hb_buffer_t::replace_glyphs (unsigned int num_in,
356 			     unsigned int num_out,
357 			     const uint32_t *glyph_data)
358 {
359   if (unlikely (!make_room_for (num_in, num_out))) return;
360 
361   merge_clusters (idx, idx + num_in);
362 
363   hb_glyph_info_t orig_info = info[idx];
364   hb_glyph_info_t *pinfo = &out_info[out_len];
365   for (unsigned int i = 0; i < num_out; i++)
366   {
367     *pinfo = orig_info;
368     pinfo->codepoint = glyph_data[i];
369     pinfo++;
370   }
371 
372   idx  += num_in;
373   out_len += num_out;
374 }
375 
376 void
output_glyph(hb_codepoint_t glyph_index)377 hb_buffer_t::output_glyph (hb_codepoint_t glyph_index)
378 {
379   if (unlikely (!make_room_for (0, 1))) return;
380 
381   out_info[out_len] = info[idx];
382   out_info[out_len].codepoint = glyph_index;
383 
384   out_len++;
385 }
386 
387 void
output_info(const hb_glyph_info_t & glyph_info)388 hb_buffer_t::output_info (const hb_glyph_info_t &glyph_info)
389 {
390   if (unlikely (!make_room_for (0, 1))) return;
391 
392   out_info[out_len] = glyph_info;
393 
394   out_len++;
395 }
396 
397 void
copy_glyph(void)398 hb_buffer_t::copy_glyph (void)
399 {
400   if (unlikely (!make_room_for (0, 1))) return;
401 
402   out_info[out_len] = info[idx];
403 
404   out_len++;
405 }
406 
407 bool
move_to(unsigned int i)408 hb_buffer_t::move_to (unsigned int i)
409 {
410   if (!have_output)
411   {
412     assert (i <= len);
413     idx = i;
414     return true;
415   }
416   if (unlikely (in_error))
417     return false;
418 
419   assert (i <= out_len + (len - idx));
420 
421   if (out_len < i)
422   {
423     unsigned int count = i - out_len;
424     if (unlikely (!make_room_for (count, count))) return false;
425 
426     memmove (out_info + out_len, info + idx, count * sizeof (out_info[0]));
427     idx += count;
428     out_len += count;
429   }
430   else if (out_len > i)
431   {
432     /* Tricky part: rewinding... */
433     unsigned int count = out_len - i;
434 
435     /* This will blow in our face if memory allocation fails later
436      * in this same lookup... */
437     if (unlikely (idx < count && !shift_forward (count + 32))) return false;
438 
439     assert (idx >= count);
440 
441     idx -= count;
442     out_len -= count;
443     memmove (info + idx, out_info + out_len, count * sizeof (out_info[0]));
444   }
445 
446   return true;
447 }
448 
449 void
replace_glyph(hb_codepoint_t glyph_index)450 hb_buffer_t::replace_glyph (hb_codepoint_t glyph_index)
451 {
452   if (unlikely (out_info != info || out_len != idx)) {
453     if (unlikely (!make_room_for (1, 1))) return;
454     out_info[out_len] = info[idx];
455   }
456   out_info[out_len].codepoint = glyph_index;
457 
458   idx++;
459   out_len++;
460 }
461 
462 
463 void
set_masks(hb_mask_t value,hb_mask_t mask,unsigned int cluster_start,unsigned int cluster_end)464 hb_buffer_t::set_masks (hb_mask_t    value,
465 			hb_mask_t    mask,
466 			unsigned int cluster_start,
467 			unsigned int cluster_end)
468 {
469   hb_mask_t not_mask = ~mask;
470   value &= mask;
471 
472   if (!mask)
473     return;
474 
475   if (cluster_start == 0 && cluster_end == (unsigned int)-1) {
476     unsigned int count = len;
477     for (unsigned int i = 0; i < count; i++)
478       info[i].mask = (info[i].mask & not_mask) | value;
479     return;
480   }
481 
482   unsigned int count = len;
483   for (unsigned int i = 0; i < count; i++)
484     if (cluster_start <= info[i].cluster && info[i].cluster < cluster_end)
485       info[i].mask = (info[i].mask & not_mask) | value;
486 }
487 
488 void
reverse_range(unsigned int start,unsigned int end)489 hb_buffer_t::reverse_range (unsigned int start,
490 			    unsigned int end)
491 {
492   unsigned int i, j;
493 
494   if (end - start < 2)
495     return;
496 
497   for (i = start, j = end - 1; i < j; i++, j--) {
498     hb_glyph_info_t t;
499 
500     t = info[i];
501     info[i] = info[j];
502     info[j] = t;
503   }
504 
505   if (have_positions) {
506     for (i = start, j = end - 1; i < j; i++, j--) {
507       hb_glyph_position_t t;
508 
509       t = pos[i];
510       pos[i] = pos[j];
511       pos[j] = t;
512     }
513   }
514 }
515 
516 void
reverse(void)517 hb_buffer_t::reverse (void)
518 {
519   if (unlikely (!len))
520     return;
521 
522   reverse_range (0, len);
523 }
524 
525 void
reverse_clusters(void)526 hb_buffer_t::reverse_clusters (void)
527 {
528   unsigned int i, start, count, last_cluster;
529 
530   if (unlikely (!len))
531     return;
532 
533   reverse ();
534 
535   count = len;
536   start = 0;
537   last_cluster = info[0].cluster;
538   for (i = 1; i < count; i++) {
539     if (last_cluster != info[i].cluster) {
540       reverse_range (start, i);
541       start = i;
542       last_cluster = info[i].cluster;
543     }
544   }
545   reverse_range (start, i);
546 }
547 
548 void
merge_clusters_impl(unsigned int start,unsigned int end)549 hb_buffer_t::merge_clusters_impl (unsigned int start,
550 				  unsigned int end)
551 {
552   if (cluster_level == HB_BUFFER_CLUSTER_LEVEL_CHARACTERS)
553     return;
554 
555   unsigned int cluster = info[start].cluster;
556 
557   for (unsigned int i = start + 1; i < end; i++)
558     cluster = MIN (cluster, info[i].cluster);
559 
560   /* Extend end */
561   while (end < len && info[end - 1].cluster == info[end].cluster)
562     end++;
563 
564   /* Extend start */
565   while (idx < start && info[start - 1].cluster == info[start].cluster)
566     start--;
567 
568   /* If we hit the start of buffer, continue in out-buffer. */
569   if (idx == start)
570     for (unsigned int i = out_len; i && out_info[i - 1].cluster == info[start].cluster; i--)
571       out_info[i - 1].cluster = cluster;
572 
573   for (unsigned int i = start; i < end; i++)
574     info[i].cluster = cluster;
575 }
576 void
merge_out_clusters(unsigned int start,unsigned int end)577 hb_buffer_t::merge_out_clusters (unsigned int start,
578 				 unsigned int end)
579 {
580   if (cluster_level == HB_BUFFER_CLUSTER_LEVEL_CHARACTERS)
581     return;
582 
583   if (unlikely (end - start < 2))
584     return;
585 
586   unsigned int cluster = out_info[start].cluster;
587 
588   for (unsigned int i = start + 1; i < end; i++)
589     cluster = MIN (cluster, out_info[i].cluster);
590 
591   /* Extend start */
592   while (start && out_info[start - 1].cluster == out_info[start].cluster)
593     start--;
594 
595   /* Extend end */
596   while (end < out_len && out_info[end - 1].cluster == out_info[end].cluster)
597     end++;
598 
599   /* If we hit the end of out-buffer, continue in buffer. */
600   if (end == out_len)
601     for (unsigned int i = idx; i < len && info[i].cluster == out_info[end - 1].cluster; i++)
602       info[i].cluster = cluster;
603 
604   for (unsigned int i = start; i < end; i++)
605     out_info[i].cluster = cluster;
606 }
607 void
delete_glyph()608 hb_buffer_t::delete_glyph ()
609 {
610   unsigned int cluster = info[idx].cluster;
611   if (idx + 1 < len && cluster == info[idx + 1].cluster)
612   {
613     /* Cluster survives; do nothing. */
614     goto done;
615   }
616 
617   if (out_len)
618   {
619     /* Merge cluster backward. */
620     if (cluster < out_info[out_len - 1].cluster)
621     {
622       unsigned int old_cluster = out_info[out_len - 1].cluster;
623       for (unsigned i = out_len; i && out_info[i - 1].cluster == old_cluster; i--)
624 	out_info[i - 1].cluster = cluster;
625     }
626     goto done;
627   }
628 
629   if (idx + 1 < len)
630   {
631     /* Merge cluster forward. */
632     merge_clusters (idx, idx + 2);
633     goto done;
634   }
635 
636 done:
637   skip_glyph ();
638 }
639 
640 void
guess_segment_properties(void)641 hb_buffer_t::guess_segment_properties (void)
642 {
643   assert (content_type == HB_BUFFER_CONTENT_TYPE_UNICODE ||
644 	  (!len && content_type == HB_BUFFER_CONTENT_TYPE_INVALID));
645 
646   /* If script is set to INVALID, guess from buffer contents */
647   if (props.script == HB_SCRIPT_INVALID) {
648     for (unsigned int i = 0; i < len; i++) {
649       hb_script_t script = unicode->script (info[i].codepoint);
650       if (likely (script != HB_SCRIPT_COMMON &&
651 		  script != HB_SCRIPT_INHERITED &&
652 		  script != HB_SCRIPT_UNKNOWN)) {
653         props.script = script;
654         break;
655       }
656     }
657   }
658 
659   /* If direction is set to INVALID, guess from script */
660   if (props.direction == HB_DIRECTION_INVALID) {
661     props.direction = hb_script_get_horizontal_direction (props.script);
662   }
663 
664   /* If language is not set, use default language from locale */
665   if (props.language == HB_LANGUAGE_INVALID) {
666     /* TODO get_default_for_script? using $LANGUAGE */
667     props.language = hb_language_get_default ();
668   }
669 }
670 
671 
672 /* Public API */
673 
674 /**
675  * hb_buffer_create: (Xconstructor)
676  *
677  * Creates a new #hb_buffer_t with all properties to defaults.
678  *
679  * Return value: (transfer full):
680  * A newly allocated #hb_buffer_t with a reference count of 1. The initial
681  * reference count should be released with hb_buffer_destroy() when you are done
682  * using the #hb_buffer_t. This function never returns %NULL. If memory cannot
683  * be allocated, a special #hb_buffer_t object will be returned on which
684  * hb_buffer_allocation_successful() returns %false.
685  *
686  * Since: 0.9.2
687  **/
688 hb_buffer_t *
hb_buffer_create(void)689 hb_buffer_create (void)
690 {
691   hb_buffer_t *buffer;
692 
693   if (!(buffer = hb_object_create<hb_buffer_t> ()))
694     return hb_buffer_get_empty ();
695 
696   buffer->max_len = HB_BUFFER_MAX_LEN_DEFAULT;
697 
698   buffer->reset ();
699 
700   return buffer;
701 }
702 
703 /**
704  * hb_buffer_get_empty:
705  *
706  *
707  *
708  * Return value: (transfer full):
709  *
710  * Since: 0.9.2
711  **/
712 hb_buffer_t *
hb_buffer_get_empty(void)713 hb_buffer_get_empty (void)
714 {
715   static const hb_buffer_t _hb_buffer_nil = {
716     HB_OBJECT_HEADER_STATIC,
717 
718     const_cast<hb_unicode_funcs_t *> (&_hb_unicode_funcs_nil),
719     HB_BUFFER_FLAG_DEFAULT,
720     HB_BUFFER_CLUSTER_LEVEL_DEFAULT,
721     HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT,
722     HB_BUFFER_SCRATCH_FLAG_DEFAULT,
723     HB_BUFFER_MAX_LEN_DEFAULT,
724 
725     HB_BUFFER_CONTENT_TYPE_INVALID,
726     HB_SEGMENT_PROPERTIES_DEFAULT,
727     true, /* in_error */
728     true, /* have_output */
729     true  /* have_positions */
730 
731     /* Zero is good enough for everything else. */
732   };
733 
734   return const_cast<hb_buffer_t *> (&_hb_buffer_nil);
735 }
736 
737 /**
738  * hb_buffer_reference: (skip)
739  * @buffer: an #hb_buffer_t.
740  *
741  * Increases the reference count on @buffer by one. This prevents @buffer from
742  * being destroyed until a matching call to hb_buffer_destroy() is made.
743  *
744  * Return value: (transfer full):
745  * The referenced #hb_buffer_t.
746  *
747  * Since: 0.9.2
748  **/
749 hb_buffer_t *
hb_buffer_reference(hb_buffer_t * buffer)750 hb_buffer_reference (hb_buffer_t *buffer)
751 {
752   return hb_object_reference (buffer);
753 }
754 
755 /**
756  * hb_buffer_destroy: (skip)
757  * @buffer: an #hb_buffer_t.
758  *
759  * Deallocate the @buffer.
760  * Decreases the reference count on @buffer by one. If the result is zero, then
761  * @buffer and all associated resources are freed. See hb_buffer_reference().
762  *
763  * Since: 0.9.2
764  **/
765 void
hb_buffer_destroy(hb_buffer_t * buffer)766 hb_buffer_destroy (hb_buffer_t *buffer)
767 {
768   if (!hb_object_destroy (buffer)) return;
769 
770   hb_unicode_funcs_destroy (buffer->unicode);
771 
772   free (buffer->info);
773   free (buffer->pos);
774   if (buffer->message_destroy)
775     buffer->message_destroy (buffer->message_data);
776 
777   free (buffer);
778 }
779 
780 /**
781  * hb_buffer_set_user_data: (skip)
782  * @buffer: an #hb_buffer_t.
783  * @key:
784  * @data:
785  * @destroy:
786  * @replace:
787  *
788  *
789  *
790  * Return value:
791  *
792  * Since: 0.9.2
793  **/
794 hb_bool_t
hb_buffer_set_user_data(hb_buffer_t * buffer,hb_user_data_key_t * key,void * data,hb_destroy_func_t destroy,hb_bool_t replace)795 hb_buffer_set_user_data (hb_buffer_t        *buffer,
796 			 hb_user_data_key_t *key,
797 			 void *              data,
798 			 hb_destroy_func_t   destroy,
799 			 hb_bool_t           replace)
800 {
801   return hb_object_set_user_data (buffer, key, data, destroy, replace);
802 }
803 
804 /**
805  * hb_buffer_get_user_data: (skip)
806  * @buffer: an #hb_buffer_t.
807  * @key:
808  *
809  *
810  *
811  * Return value:
812  *
813  * Since: 0.9.2
814  **/
815 void *
hb_buffer_get_user_data(hb_buffer_t * buffer,hb_user_data_key_t * key)816 hb_buffer_get_user_data (hb_buffer_t        *buffer,
817 			 hb_user_data_key_t *key)
818 {
819   return hb_object_get_user_data (buffer, key);
820 }
821 
822 
823 /**
824  * hb_buffer_set_content_type:
825  * @buffer: an #hb_buffer_t.
826  * @content_type: the type of buffer contents to set
827  *
828  * Sets the type of @buffer contents, buffers are either empty, contain
829  * characters (before shaping) or glyphs (the result of shaping).
830  *
831  * Since: 0.9.5
832  **/
833 void
hb_buffer_set_content_type(hb_buffer_t * buffer,hb_buffer_content_type_t content_type)834 hb_buffer_set_content_type (hb_buffer_t              *buffer,
835 			    hb_buffer_content_type_t  content_type)
836 {
837   buffer->content_type = content_type;
838 }
839 
840 /**
841  * hb_buffer_get_content_type:
842  * @buffer: an #hb_buffer_t.
843  *
844  * see hb_buffer_set_content_type().
845  *
846  * Return value:
847  * The type of @buffer contents.
848  *
849  * Since: 0.9.5
850  **/
851 hb_buffer_content_type_t
hb_buffer_get_content_type(hb_buffer_t * buffer)852 hb_buffer_get_content_type (hb_buffer_t *buffer)
853 {
854   return buffer->content_type;
855 }
856 
857 
858 /**
859  * hb_buffer_set_unicode_funcs:
860  * @buffer: an #hb_buffer_t.
861  * @unicode_funcs:
862  *
863  *
864  *
865  * Since: 0.9.2
866  **/
867 void
hb_buffer_set_unicode_funcs(hb_buffer_t * buffer,hb_unicode_funcs_t * unicode_funcs)868 hb_buffer_set_unicode_funcs (hb_buffer_t        *buffer,
869 			     hb_unicode_funcs_t *unicode_funcs)
870 {
871   if (unlikely (hb_object_is_inert (buffer)))
872     return;
873 
874   if (!unicode_funcs)
875     unicode_funcs = hb_unicode_funcs_get_default ();
876 
877 
878   hb_unicode_funcs_reference (unicode_funcs);
879   hb_unicode_funcs_destroy (buffer->unicode);
880   buffer->unicode = unicode_funcs;
881 }
882 
883 /**
884  * hb_buffer_get_unicode_funcs:
885  * @buffer: an #hb_buffer_t.
886  *
887  *
888  *
889  * Return value:
890  *
891  * Since: 0.9.2
892  **/
893 hb_unicode_funcs_t *
hb_buffer_get_unicode_funcs(hb_buffer_t * buffer)894 hb_buffer_get_unicode_funcs (hb_buffer_t        *buffer)
895 {
896   return buffer->unicode;
897 }
898 
899 /**
900  * hb_buffer_set_direction:
901  * @buffer: an #hb_buffer_t.
902  * @direction: the #hb_direction_t of the @buffer
903  *
904  * Set the text flow direction of the buffer. No shaping can happen without
905  * setting @buffer direction, and it controls the visual direction for the
906  * output glyphs; for RTL direction the glyphs will be reversed. Many layout
907  * features depend on the proper setting of the direction, for example,
908  * reversing RTL text before shaping, then shaping with LTR direction is not
909  * the same as keeping the text in logical order and shaping with RTL
910  * direction.
911  *
912  * Since: 0.9.2
913  **/
914 void
hb_buffer_set_direction(hb_buffer_t * buffer,hb_direction_t direction)915 hb_buffer_set_direction (hb_buffer_t    *buffer,
916 			 hb_direction_t  direction)
917 
918 {
919   if (unlikely (hb_object_is_inert (buffer)))
920     return;
921 
922   buffer->props.direction = direction;
923 }
924 
925 /**
926  * hb_buffer_get_direction:
927  * @buffer: an #hb_buffer_t.
928  *
929  * See hb_buffer_set_direction()
930  *
931  * Return value:
932  * The direction of the @buffer.
933  *
934  * Since: 0.9.2
935  **/
936 hb_direction_t
hb_buffer_get_direction(hb_buffer_t * buffer)937 hb_buffer_get_direction (hb_buffer_t    *buffer)
938 {
939   return buffer->props.direction;
940 }
941 
942 /**
943  * hb_buffer_set_script:
944  * @buffer: an #hb_buffer_t.
945  * @script: an #hb_script_t to set.
946  *
947  * Sets the script of @buffer to @script.
948  *
949  * Script is crucial for choosing the proper shaping behaviour for scripts that
950  * require it (e.g. Arabic) and the which OpenType features defined in the font
951  * to be applied.
952  *
953  * You can pass one of the predefined #hb_script_t values, or use
954  * hb_script_from_string() or hb_script_from_iso15924_tag() to get the
955  * corresponding script from an ISO 15924 script tag.
956  *
957  * Since: 0.9.2
958  **/
959 void
hb_buffer_set_script(hb_buffer_t * buffer,hb_script_t script)960 hb_buffer_set_script (hb_buffer_t *buffer,
961 		      hb_script_t  script)
962 {
963   if (unlikely (hb_object_is_inert (buffer)))
964     return;
965 
966   buffer->props.script = script;
967 }
968 
969 /**
970  * hb_buffer_get_script:
971  * @buffer: an #hb_buffer_t.
972  *
973  * See hb_buffer_set_script().
974  *
975  * Return value:
976  * The #hb_script_t of the @buffer.
977  *
978  * Since: 0.9.2
979  **/
980 hb_script_t
hb_buffer_get_script(hb_buffer_t * buffer)981 hb_buffer_get_script (hb_buffer_t *buffer)
982 {
983   return buffer->props.script;
984 }
985 
986 /**
987  * hb_buffer_set_language:
988  * @buffer: an #hb_buffer_t.
989  * @language: an hb_language_t to set.
990  *
991  * Sets the language of @buffer to @language.
992  *
993  * Languages are crucial for selecting which OpenType feature to apply to the
994  * buffer which can result in applying language-specific behaviour. Languages
995  * are orthogonal to the scripts, and though they are related, they are
996  * different concepts and should not be confused with each other.
997  *
998  * Use hb_language_from_string() to convert from ISO 639 language codes to
999  * #hb_language_t.
1000  *
1001  * Since: 0.9.2
1002  **/
1003 void
hb_buffer_set_language(hb_buffer_t * buffer,hb_language_t language)1004 hb_buffer_set_language (hb_buffer_t   *buffer,
1005 			hb_language_t  language)
1006 {
1007   if (unlikely (hb_object_is_inert (buffer)))
1008     return;
1009 
1010   buffer->props.language = language;
1011 }
1012 
1013 /**
1014  * hb_buffer_get_language:
1015  * @buffer: an #hb_buffer_t.
1016  *
1017  * See hb_buffer_set_language().
1018  *
1019  * Return value: (transfer none):
1020  * The #hb_language_t of the buffer. Must not be freed by the caller.
1021  *
1022  * Since: 0.9.2
1023  **/
1024 hb_language_t
hb_buffer_get_language(hb_buffer_t * buffer)1025 hb_buffer_get_language (hb_buffer_t *buffer)
1026 {
1027   return buffer->props.language;
1028 }
1029 
1030 /**
1031  * hb_buffer_set_segment_properties:
1032  * @buffer: an #hb_buffer_t.
1033  * @props: an #hb_segment_properties_t to use.
1034  *
1035  * Sets the segment properties of the buffer, a shortcut for calling
1036  * hb_buffer_set_direction(), hb_buffer_set_script() and
1037  * hb_buffer_set_language() individually.
1038  *
1039  * Since: 0.9.7
1040  **/
1041 void
hb_buffer_set_segment_properties(hb_buffer_t * buffer,const hb_segment_properties_t * props)1042 hb_buffer_set_segment_properties (hb_buffer_t *buffer,
1043 				  const hb_segment_properties_t *props)
1044 {
1045   if (unlikely (hb_object_is_inert (buffer)))
1046     return;
1047 
1048   buffer->props = *props;
1049 }
1050 
1051 /**
1052  * hb_buffer_get_segment_properties:
1053  * @buffer: an #hb_buffer_t.
1054  * @props: (out): the output #hb_segment_properties_t.
1055  *
1056  * Sets @props to the #hb_segment_properties_t of @buffer.
1057  *
1058  * Since: 0.9.7
1059  **/
1060 void
hb_buffer_get_segment_properties(hb_buffer_t * buffer,hb_segment_properties_t * props)1061 hb_buffer_get_segment_properties (hb_buffer_t *buffer,
1062 				  hb_segment_properties_t *props)
1063 {
1064   *props = buffer->props;
1065 }
1066 
1067 
1068 /**
1069  * hb_buffer_set_flags:
1070  * @buffer: an #hb_buffer_t.
1071  * @flags: the buffer flags to set.
1072  *
1073  * Sets @buffer flags to @flags. See #hb_buffer_flags_t.
1074  *
1075  * Since: 0.9.7
1076  **/
1077 void
hb_buffer_set_flags(hb_buffer_t * buffer,hb_buffer_flags_t flags)1078 hb_buffer_set_flags (hb_buffer_t       *buffer,
1079 		     hb_buffer_flags_t  flags)
1080 {
1081   if (unlikely (hb_object_is_inert (buffer)))
1082     return;
1083 
1084   buffer->flags = flags;
1085 }
1086 
1087 /**
1088  * hb_buffer_get_flags:
1089  * @buffer: an #hb_buffer_t.
1090  *
1091  * See hb_buffer_set_flags().
1092  *
1093  * Return value:
1094  * The @buffer flags.
1095  *
1096  * Since: 0.9.7
1097  **/
1098 hb_buffer_flags_t
hb_buffer_get_flags(hb_buffer_t * buffer)1099 hb_buffer_get_flags (hb_buffer_t *buffer)
1100 {
1101   return buffer->flags;
1102 }
1103 
1104 /**
1105  * hb_buffer_set_cluster_level:
1106  * @buffer: an #hb_buffer_t.
1107  * @cluster_level:
1108  *
1109  *
1110  *
1111  * Since: 0.9.42
1112  **/
1113 void
hb_buffer_set_cluster_level(hb_buffer_t * buffer,hb_buffer_cluster_level_t cluster_level)1114 hb_buffer_set_cluster_level (hb_buffer_t       *buffer,
1115 		     hb_buffer_cluster_level_t  cluster_level)
1116 {
1117   if (unlikely (hb_object_is_inert (buffer)))
1118     return;
1119 
1120   buffer->cluster_level = cluster_level;
1121 }
1122 
1123 /**
1124  * hb_buffer_get_cluster_level:
1125  * @buffer: an #hb_buffer_t.
1126  *
1127  *
1128  *
1129  * Return value:
1130  *
1131  * Since: 0.9.42
1132  **/
1133 hb_buffer_cluster_level_t
hb_buffer_get_cluster_level(hb_buffer_t * buffer)1134 hb_buffer_get_cluster_level (hb_buffer_t *buffer)
1135 {
1136   return buffer->cluster_level;
1137 }
1138 
1139 
1140 /**
1141  * hb_buffer_set_replacement_codepoint:
1142  * @buffer: an #hb_buffer_t.
1143  * @replacement: the replacement #hb_codepoint_t
1144  *
1145  * Sets the #hb_codepoint_t that replaces invalid entries for a given encoding
1146  * when adding text to @buffer.
1147  *
1148  * Default is %HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT.
1149  *
1150  * Since: 0.9.31
1151  **/
1152 void
hb_buffer_set_replacement_codepoint(hb_buffer_t * buffer,hb_codepoint_t replacement)1153 hb_buffer_set_replacement_codepoint (hb_buffer_t    *buffer,
1154 				     hb_codepoint_t  replacement)
1155 {
1156   if (unlikely (hb_object_is_inert (buffer)))
1157     return;
1158 
1159   buffer->replacement = replacement;
1160 }
1161 
1162 /**
1163  * hb_buffer_get_replacement_codepoint:
1164  * @buffer: an #hb_buffer_t.
1165  *
1166  * See hb_buffer_set_replacement_codepoint().
1167  *
1168  * Return value:
1169  * The @buffer replacement #hb_codepoint_t.
1170  *
1171  * Since: 0.9.31
1172  **/
1173 hb_codepoint_t
hb_buffer_get_replacement_codepoint(hb_buffer_t * buffer)1174 hb_buffer_get_replacement_codepoint (hb_buffer_t    *buffer)
1175 {
1176   return buffer->replacement;
1177 }
1178 
1179 
1180 /**
1181  * hb_buffer_reset:
1182  * @buffer: an #hb_buffer_t.
1183  *
1184  * Resets the buffer to its initial status, as if it was just newly created
1185  * with hb_buffer_create().
1186  *
1187  * Since: 0.9.2
1188  **/
1189 void
hb_buffer_reset(hb_buffer_t * buffer)1190 hb_buffer_reset (hb_buffer_t *buffer)
1191 {
1192   buffer->reset ();
1193 }
1194 
1195 /**
1196  * hb_buffer_clear_contents:
1197  * @buffer: an #hb_buffer_t.
1198  *
1199  * Similar to hb_buffer_reset(), but does not clear the Unicode functions and
1200  * the replacement code point.
1201  *
1202  * Since: 0.9.11
1203  **/
1204 void
hb_buffer_clear_contents(hb_buffer_t * buffer)1205 hb_buffer_clear_contents (hb_buffer_t *buffer)
1206 {
1207   buffer->clear ();
1208 }
1209 
1210 /**
1211  * hb_buffer_pre_allocate:
1212  * @buffer: an #hb_buffer_t.
1213  * @size: number of items to pre allocate.
1214  *
1215  * Pre allocates memory for @buffer to fit at least @size number of items.
1216  *
1217  * Return value:
1218  * %true if @buffer memory allocation succeeded, %false otherwise.
1219  *
1220  * Since: 0.9.2
1221  **/
1222 hb_bool_t
hb_buffer_pre_allocate(hb_buffer_t * buffer,unsigned int size)1223 hb_buffer_pre_allocate (hb_buffer_t *buffer, unsigned int size)
1224 {
1225   return buffer->ensure (size);
1226 }
1227 
1228 /**
1229  * hb_buffer_allocation_successful:
1230  * @buffer: an #hb_buffer_t.
1231  *
1232  * Check if allocating memory for the buffer succeeded.
1233  *
1234  * Return value:
1235  * %true if @buffer memory allocation succeeded, %false otherwise.
1236  *
1237  * Since: 0.9.2
1238  **/
1239 hb_bool_t
hb_buffer_allocation_successful(hb_buffer_t * buffer)1240 hb_buffer_allocation_successful (hb_buffer_t  *buffer)
1241 {
1242   return !buffer->in_error;
1243 }
1244 
1245 /**
1246  * hb_buffer_add:
1247  * @buffer: an #hb_buffer_t.
1248  * @codepoint: a Unicode code point.
1249  * @cluster: the cluster value of @codepoint.
1250  *
1251  * Appends a character with the Unicode value of @codepoint to @buffer, and
1252  * gives it the initial cluster value of @cluster. Clusters can be any thing
1253  * the client wants, they are usually used to refer to the index of the
1254  * character in the input text stream and are output in
1255  * #hb_glyph_info_t.cluster field.
1256  *
1257  * This function does not check the validity of @codepoint, it is up to the
1258  * caller to ensure it is a valid Unicode code point.
1259  *
1260  * Since: 0.9.7
1261  **/
1262 void
hb_buffer_add(hb_buffer_t * buffer,hb_codepoint_t codepoint,unsigned int cluster)1263 hb_buffer_add (hb_buffer_t    *buffer,
1264 	       hb_codepoint_t  codepoint,
1265 	       unsigned int    cluster)
1266 {
1267   buffer->add (codepoint, cluster);
1268   buffer->clear_context (1);
1269 }
1270 
1271 /**
1272  * hb_buffer_set_length:
1273  * @buffer: an #hb_buffer_t.
1274  * @length: the new length of @buffer.
1275  *
1276  * Similar to hb_buffer_pre_allocate(), but clears any new items added at the
1277  * end.
1278  *
1279  * Return value:
1280  * %true if @buffer memory allocation succeeded, %false otherwise.
1281  *
1282  * Since: 0.9.2
1283  **/
1284 hb_bool_t
hb_buffer_set_length(hb_buffer_t * buffer,unsigned int length)1285 hb_buffer_set_length (hb_buffer_t  *buffer,
1286 		      unsigned int  length)
1287 {
1288   if (unlikely (hb_object_is_inert (buffer)))
1289     return length == 0;
1290 
1291   if (!buffer->ensure (length))
1292     return false;
1293 
1294   /* Wipe the new space */
1295   if (length > buffer->len) {
1296     memset (buffer->info + buffer->len, 0, sizeof (buffer->info[0]) * (length - buffer->len));
1297     if (buffer->have_positions)
1298       memset (buffer->pos + buffer->len, 0, sizeof (buffer->pos[0]) * (length - buffer->len));
1299   }
1300 
1301   buffer->len = length;
1302 
1303   if (!length)
1304   {
1305     buffer->content_type = HB_BUFFER_CONTENT_TYPE_INVALID;
1306     buffer->clear_context (0);
1307   }
1308   buffer->clear_context (1);
1309 
1310   return true;
1311 }
1312 
1313 /**
1314  * hb_buffer_get_length:
1315  * @buffer: an #hb_buffer_t.
1316  *
1317  * Returns the number of items in the buffer.
1318  *
1319  * Return value:
1320  * The @buffer length.
1321  * The value valid as long as buffer has not been modified.
1322  *
1323  * Since: 0.9.2
1324  **/
1325 unsigned int
hb_buffer_get_length(hb_buffer_t * buffer)1326 hb_buffer_get_length (hb_buffer_t *buffer)
1327 {
1328   return buffer->len;
1329 }
1330 
1331 /**
1332  * hb_buffer_get_glyph_infos:
1333  * @buffer: an #hb_buffer_t.
1334  * @length: (out): output array length.
1335  *
1336  * Returns @buffer glyph information array.  Returned pointer
1337  * is valid as long as @buffer contents are not modified.
1338  *
1339  * Return value: (transfer none) (array length=length):
1340  * The @buffer glyph information array.
1341  * The value valid as long as buffer has not been modified.
1342  *
1343  * Since: 0.9.2
1344  **/
1345 hb_glyph_info_t *
hb_buffer_get_glyph_infos(hb_buffer_t * buffer,unsigned int * length)1346 hb_buffer_get_glyph_infos (hb_buffer_t  *buffer,
1347                            unsigned int *length)
1348 {
1349   if (length)
1350     *length = buffer->len;
1351 
1352   return (hb_glyph_info_t *) buffer->info;
1353 }
1354 
1355 /**
1356  * hb_buffer_get_glyph_positions:
1357  * @buffer: an #hb_buffer_t.
1358  * @length: (out): output length.
1359  *
1360  * Returns @buffer glyph position array.  Returned pointer
1361  * is valid as long as @buffer contents are not modified.
1362  *
1363  * Return value: (transfer none) (array length=length):
1364  * The @buffer glyph position array.
1365  * The value valid as long as buffer has not been modified.
1366  *
1367  * Since: 0.9.2
1368  **/
1369 hb_glyph_position_t *
hb_buffer_get_glyph_positions(hb_buffer_t * buffer,unsigned int * length)1370 hb_buffer_get_glyph_positions (hb_buffer_t  *buffer,
1371                                unsigned int *length)
1372 {
1373   if (!buffer->have_positions)
1374     buffer->clear_positions ();
1375 
1376   if (length)
1377     *length = buffer->len;
1378 
1379   return (hb_glyph_position_t *) buffer->pos;
1380 }
1381 
1382 /**
1383  * hb_buffer_reverse:
1384  * @buffer: an #hb_buffer_t.
1385  *
1386  * Reverses buffer contents.
1387  *
1388  * Since: 0.9.2
1389  **/
1390 void
hb_buffer_reverse(hb_buffer_t * buffer)1391 hb_buffer_reverse (hb_buffer_t *buffer)
1392 {
1393   buffer->reverse ();
1394 }
1395 
1396 /**
1397  * hb_buffer_reverse_range:
1398  * @buffer: an #hb_buffer_t.
1399  * @start: start index.
1400  * @end: end index.
1401  *
1402  * Reverses buffer contents between start to end.
1403  *
1404  * Since: 0.9.41
1405  **/
1406 void
hb_buffer_reverse_range(hb_buffer_t * buffer,unsigned int start,unsigned int end)1407 hb_buffer_reverse_range (hb_buffer_t *buffer,
1408 			 unsigned int start, unsigned int end)
1409 {
1410   buffer->reverse_range (start, end);
1411 }
1412 
1413 /**
1414  * hb_buffer_reverse_clusters:
1415  * @buffer: an #hb_buffer_t.
1416  *
1417  * Reverses buffer clusters.  That is, the buffer contents are
1418  * reversed, then each cluster (consecutive items having the
1419  * same cluster number) are reversed again.
1420  *
1421  * Since: 0.9.2
1422  **/
1423 void
hb_buffer_reverse_clusters(hb_buffer_t * buffer)1424 hb_buffer_reverse_clusters (hb_buffer_t *buffer)
1425 {
1426   buffer->reverse_clusters ();
1427 }
1428 
1429 /**
1430  * hb_buffer_guess_segment_properties:
1431  * @buffer: an #hb_buffer_t.
1432  *
1433  * Sets unset buffer segment properties based on buffer Unicode
1434  * contents.  If buffer is not empty, it must have content type
1435  * %HB_BUFFER_CONTENT_TYPE_UNICODE.
1436  *
1437  * If buffer script is not set (ie. is %HB_SCRIPT_INVALID), it
1438  * will be set to the Unicode script of the first character in
1439  * the buffer that has a script other than %HB_SCRIPT_COMMON,
1440  * %HB_SCRIPT_INHERITED, and %HB_SCRIPT_UNKNOWN.
1441  *
1442  * Next, if buffer direction is not set (ie. is %HB_DIRECTION_INVALID),
1443  * it will be set to the natural horizontal direction of the
1444  * buffer script as returned by hb_script_get_horizontal_direction().
1445  *
1446  * Finally, if buffer language is not set (ie. is %HB_LANGUAGE_INVALID),
1447  * it will be set to the process's default language as returned by
1448  * hb_language_get_default().  This may change in the future by
1449  * taking buffer script into consideration when choosing a language.
1450  *
1451  * Since: 0.9.7
1452  **/
1453 void
hb_buffer_guess_segment_properties(hb_buffer_t * buffer)1454 hb_buffer_guess_segment_properties (hb_buffer_t *buffer)
1455 {
1456   buffer->guess_segment_properties ();
1457 }
1458 
1459 template <typename utf_t>
1460 static inline void
hb_buffer_add_utf(hb_buffer_t * buffer,const typename utf_t::codepoint_t * text,int text_length,unsigned int item_offset,int item_length)1461 hb_buffer_add_utf (hb_buffer_t  *buffer,
1462 		   const typename utf_t::codepoint_t *text,
1463 		   int           text_length,
1464 		   unsigned int  item_offset,
1465 		   int           item_length)
1466 {
1467   typedef typename utf_t::codepoint_t T;
1468   const hb_codepoint_t replacement = buffer->replacement;
1469 
1470   assert (buffer->content_type == HB_BUFFER_CONTENT_TYPE_UNICODE ||
1471 	  (!buffer->len && buffer->content_type == HB_BUFFER_CONTENT_TYPE_INVALID));
1472 
1473   if (unlikely (hb_object_is_inert (buffer)))
1474     return;
1475 
1476   if (text_length == -1)
1477     text_length = utf_t::strlen (text);
1478 
1479   if (item_length == -1)
1480     item_length = text_length - item_offset;
1481 
1482   buffer->ensure (buffer->len + item_length * sizeof (T) / 4);
1483 
1484   /* If buffer is empty and pre-context provided, install it.
1485    * This check is written this way, to make sure people can
1486    * provide pre-context in one add_utf() call, then provide
1487    * text in a follow-up call.  See:
1488    *
1489    * https://bugzilla.mozilla.org/show_bug.cgi?id=801410#c13
1490    */
1491   if (!buffer->len && item_offset > 0)
1492   {
1493     /* Add pre-context */
1494     buffer->clear_context (0);
1495     const T *prev = text + item_offset;
1496     const T *start = text;
1497     while (start < prev && buffer->context_len[0] < buffer->CONTEXT_LENGTH)
1498     {
1499       hb_codepoint_t u;
1500       prev = utf_t::prev (prev, start, &u, replacement);
1501       buffer->context[0][buffer->context_len[0]++] = u;
1502     }
1503   }
1504 
1505   const T *next = text + item_offset;
1506   const T *end = next + item_length;
1507   while (next < end)
1508   {
1509     hb_codepoint_t u;
1510     const T *old_next = next;
1511     next = utf_t::next (next, end, &u, replacement);
1512     buffer->add (u, old_next - (const T *) text);
1513   }
1514 
1515   /* Add post-context */
1516   buffer->clear_context (1);
1517   end = text + text_length;
1518   while (next < end && buffer->context_len[1] < buffer->CONTEXT_LENGTH)
1519   {
1520     hb_codepoint_t u;
1521     next = utf_t::next (next, end, &u, replacement);
1522     buffer->context[1][buffer->context_len[1]++] = u;
1523   }
1524 
1525   buffer->content_type = HB_BUFFER_CONTENT_TYPE_UNICODE;
1526 }
1527 
1528 /**
1529  * hb_buffer_add_utf8:
1530  * @buffer: an #hb_buffer_t.
1531  * @text: (array length=text_length) (element-type uint8_t): an array of UTF-8
1532  *               characters to append.
1533  * @text_length: the length of the @text, or -1 if it is %NULL terminated.
1534  * @item_offset: the offset of the first character to add to the @buffer.
1535  * @item_length: the number of characters to add to the @buffer, or -1 for the
1536  *               end of @text (assuming it is %NULL terminated).
1537  *
1538  * See hb_buffer_add_codepoints().
1539  *
1540  * Replaces invalid UTF-8 characters with the @buffer replacement code point,
1541  * see hb_buffer_set_replacement_codepoint().
1542  *
1543  * Since: 0.9.2
1544  **/
1545 void
hb_buffer_add_utf8(hb_buffer_t * buffer,const char * text,int text_length,unsigned int item_offset,int item_length)1546 hb_buffer_add_utf8 (hb_buffer_t  *buffer,
1547 		    const char   *text,
1548 		    int           text_length,
1549 		    unsigned int  item_offset,
1550 		    int           item_length)
1551 {
1552   hb_buffer_add_utf<hb_utf8_t> (buffer, (const uint8_t *) text, text_length, item_offset, item_length);
1553 }
1554 
1555 /**
1556  * hb_buffer_add_utf16:
1557  * @buffer: an #hb_buffer_t.
1558  * @text: (array length=text_length): an array of UTF-16 characters to append.
1559  * @text_length: the length of the @text, or -1 if it is %NULL terminated.
1560  * @item_offset: the offset of the first character to add to the @buffer.
1561  * @item_length: the number of characters to add to the @buffer, or -1 for the
1562  *               end of @text (assuming it is %NULL terminated).
1563  *
1564  * See hb_buffer_add_codepoints().
1565  *
1566  * Replaces invalid UTF-16 characters with the @buffer replacement code point,
1567  * see hb_buffer_set_replacement_codepoint().
1568  *
1569  * Since: 0.9.2
1570  **/
1571 void
hb_buffer_add_utf16(hb_buffer_t * buffer,const uint16_t * text,int text_length,unsigned int item_offset,int item_length)1572 hb_buffer_add_utf16 (hb_buffer_t    *buffer,
1573 		     const uint16_t *text,
1574 		     int             text_length,
1575 		     unsigned int    item_offset,
1576 		     int             item_length)
1577 {
1578   hb_buffer_add_utf<hb_utf16_t> (buffer, text, text_length, item_offset, item_length);
1579 }
1580 
1581 /**
1582  * hb_buffer_add_utf32:
1583  * @buffer: an #hb_buffer_t.
1584  * @text: (array length=text_length): an array of UTF-32 characters to append.
1585  * @text_length: the length of the @text, or -1 if it is %NULL terminated.
1586  * @item_offset: the offset of the first character to add to the @buffer.
1587  * @item_length: the number of characters to add to the @buffer, or -1 for the
1588  *               end of @text (assuming it is %NULL terminated).
1589  *
1590  * See hb_buffer_add_codepoints().
1591  *
1592  * Replaces invalid UTF-32 characters with the @buffer replacement code point,
1593  * see hb_buffer_set_replacement_codepoint().
1594  *
1595  * Since: 0.9.2
1596  **/
1597 void
hb_buffer_add_utf32(hb_buffer_t * buffer,const uint32_t * text,int text_length,unsigned int item_offset,int item_length)1598 hb_buffer_add_utf32 (hb_buffer_t    *buffer,
1599 		     const uint32_t *text,
1600 		     int             text_length,
1601 		     unsigned int    item_offset,
1602 		     int             item_length)
1603 {
1604   hb_buffer_add_utf<hb_utf32_t<> > (buffer, text, text_length, item_offset, item_length);
1605 }
1606 
1607 /**
1608  * hb_buffer_add_latin1:
1609  * @buffer: an #hb_buffer_t.
1610  * @text: (array length=text_length) (element-type uint8_t): an array of UTF-8
1611  *               characters to append.
1612  * @text_length: the length of the @text, or -1 if it is %NULL terminated.
1613  * @item_offset: the offset of the first character to add to the @buffer.
1614  * @item_length: the number of characters to add to the @buffer, or -1 for the
1615  *               end of @text (assuming it is %NULL terminated).
1616  *
1617  * Similar to hb_buffer_add_codepoints(), but allows only access to first 256
1618  * Unicode code points that can fit in 8-bit strings.
1619  *
1620  * <note>Has nothing to do with non-Unicode Latin-1 encoding.</note>
1621  *
1622  * Since: 0.9.39
1623  **/
1624 void
hb_buffer_add_latin1(hb_buffer_t * buffer,const uint8_t * text,int text_length,unsigned int item_offset,int item_length)1625 hb_buffer_add_latin1 (hb_buffer_t   *buffer,
1626 		      const uint8_t *text,
1627 		      int            text_length,
1628 		      unsigned int   item_offset,
1629 		      int            item_length)
1630 {
1631   hb_buffer_add_utf<hb_latin1_t> (buffer, text, text_length, item_offset, item_length);
1632 }
1633 
1634 /**
1635  * hb_buffer_add_codepoints:
1636  * @buffer: a #hb_buffer_t to append characters to.
1637  * @text: (array length=text_length): an array of Unicode code points to append.
1638  * @text_length: the length of the @text, or -1 if it is %NULL terminated.
1639  * @item_offset: the offset of the first code point to add to the @buffer.
1640  * @item_length: the number of code points to add to the @buffer, or -1 for the
1641  *               end of @text (assuming it is %NULL terminated).
1642  *
1643  * Appends characters from @text array to @buffer. The @item_offset is the
1644  * position of the first character from @text that will be appended, and
1645  * @item_length is the number of character. When shaping part of a larger text
1646  * (e.g. a run of text from a paragraph), instead of passing just the substring
1647  * corresponding to the run, it is preferable to pass the whole
1648  * paragraph and specify the run start and length as @item_offset and
1649  * @item_length, respectively, to give HarfBuzz the full context to be able,
1650  * for example, to do cross-run Arabic shaping or properly handle combining
1651  * marks at stat of run.
1652  *
1653  * This function does not check the validity of @text, it is up to the caller
1654  * to ensure it contains a valid Unicode code points.
1655  *
1656  * Since: 0.9.31
1657  **/
1658 void
hb_buffer_add_codepoints(hb_buffer_t * buffer,const hb_codepoint_t * text,int text_length,unsigned int item_offset,int item_length)1659 hb_buffer_add_codepoints (hb_buffer_t          *buffer,
1660 			  const hb_codepoint_t *text,
1661 			  int                   text_length,
1662 			  unsigned int          item_offset,
1663 			  int                   item_length)
1664 {
1665   hb_buffer_add_utf<hb_utf32_t<false> > (buffer, text, text_length, item_offset, item_length);
1666 }
1667 
1668 
1669 static int
compare_info_codepoint(const hb_glyph_info_t * pa,const hb_glyph_info_t * pb)1670 compare_info_codepoint (const hb_glyph_info_t *pa,
1671 			const hb_glyph_info_t *pb)
1672 {
1673   return (int) pb->codepoint - (int) pa->codepoint;
1674 }
1675 
1676 static inline void
normalize_glyphs_cluster(hb_buffer_t * buffer,unsigned int start,unsigned int end,bool backward)1677 normalize_glyphs_cluster (hb_buffer_t *buffer,
1678 			  unsigned int start,
1679 			  unsigned int end,
1680 			  bool backward)
1681 {
1682   hb_glyph_position_t *pos = buffer->pos;
1683 
1684   /* Total cluster advance */
1685   hb_position_t total_x_advance = 0, total_y_advance = 0;
1686   for (unsigned int i = start; i < end; i++)
1687   {
1688     total_x_advance += pos[i].x_advance;
1689     total_y_advance += pos[i].y_advance;
1690   }
1691 
1692   hb_position_t x_advance = 0, y_advance = 0;
1693   for (unsigned int i = start; i < end; i++)
1694   {
1695     pos[i].x_offset += x_advance;
1696     pos[i].y_offset += y_advance;
1697 
1698     x_advance += pos[i].x_advance;
1699     y_advance += pos[i].y_advance;
1700 
1701     pos[i].x_advance = 0;
1702     pos[i].y_advance = 0;
1703   }
1704 
1705   if (backward)
1706   {
1707     /* Transfer all cluster advance to the last glyph. */
1708     pos[end - 1].x_advance = total_x_advance;
1709     pos[end - 1].y_advance = total_y_advance;
1710 
1711     hb_stable_sort (buffer->info + start, end - start - 1, compare_info_codepoint, buffer->pos + start);
1712   } else {
1713     /* Transfer all cluster advance to the first glyph. */
1714     pos[start].x_advance += total_x_advance;
1715     pos[start].y_advance += total_y_advance;
1716     for (unsigned int i = start + 1; i < end; i++) {
1717       pos[i].x_offset -= total_x_advance;
1718       pos[i].y_offset -= total_y_advance;
1719     }
1720     hb_stable_sort (buffer->info + start + 1, end - start - 1, compare_info_codepoint, buffer->pos + start + 1);
1721   }
1722 }
1723 
1724 /**
1725  * hb_buffer_normalize_glyphs:
1726  * @buffer: an #hb_buffer_t.
1727  *
1728  * Reorders a glyph buffer to have canonical in-cluster glyph order / position.
1729  * The resulting clusters should behave identical to pre-reordering clusters.
1730  *
1731  * <note>This has nothing to do with Unicode normalization.</note>
1732  *
1733  * Since: 0.9.2
1734  **/
1735 void
hb_buffer_normalize_glyphs(hb_buffer_t * buffer)1736 hb_buffer_normalize_glyphs (hb_buffer_t *buffer)
1737 {
1738   assert (buffer->have_positions);
1739   assert (buffer->content_type == HB_BUFFER_CONTENT_TYPE_GLYPHS);
1740 
1741   bool backward = HB_DIRECTION_IS_BACKWARD (buffer->props.direction);
1742 
1743   unsigned int count = buffer->len;
1744   if (unlikely (!count)) return;
1745   hb_glyph_info_t *info = buffer->info;
1746 
1747   unsigned int start = 0;
1748   unsigned int end;
1749   for (end = start + 1; end < count; end++)
1750     if (info[start].cluster != info[end].cluster) {
1751       normalize_glyphs_cluster (buffer, start, end, backward);
1752       start = end;
1753     }
1754   normalize_glyphs_cluster (buffer, start, end, backward);
1755 }
1756 
1757 void
sort(unsigned int start,unsigned int end,int (* compar)(const hb_glyph_info_t *,const hb_glyph_info_t *))1758 hb_buffer_t::sort (unsigned int start, unsigned int end, int(*compar)(const hb_glyph_info_t *, const hb_glyph_info_t *))
1759 {
1760   assert (!have_positions);
1761   for (unsigned int i = start + 1; i < end; i++)
1762   {
1763     unsigned int j = i;
1764     while (j > start && compar (&info[j - 1], &info[i]) > 0)
1765       j--;
1766     if (i == j)
1767       continue;
1768     /* Move item i to occupy place for item j, shift what's in between. */
1769     merge_clusters (j, i + 1);
1770     {
1771       hb_glyph_info_t t = info[i];
1772       memmove (&info[j + 1], &info[j], (i - j) * sizeof (hb_glyph_info_t));
1773       info[j] = t;
1774     }
1775   }
1776 }
1777 
1778 /*
1779  * Debugging.
1780  */
1781 
1782 /**
1783  * hb_buffer_set_message_func:
1784  * @buffer: an #hb_buffer_t.
1785  * @func: (closure user_data) (destroy destroy) (scope notified):
1786  * @user_data:
1787  * @destroy:
1788  *
1789  *
1790  *
1791  * Since: 1.1.3
1792  **/
1793 void
hb_buffer_set_message_func(hb_buffer_t * buffer,hb_buffer_message_func_t func,void * user_data,hb_destroy_func_t destroy)1794 hb_buffer_set_message_func (hb_buffer_t *buffer,
1795 			    hb_buffer_message_func_t func,
1796 			    void *user_data, hb_destroy_func_t destroy)
1797 {
1798   if (buffer->message_destroy)
1799     buffer->message_destroy (buffer->message_data);
1800 
1801   if (func) {
1802     buffer->message_func = func;
1803     buffer->message_data = user_data;
1804     buffer->message_destroy = destroy;
1805   } else {
1806     buffer->message_func = NULL;
1807     buffer->message_data = NULL;
1808     buffer->message_destroy = NULL;
1809   }
1810 }
1811 
1812 bool
message_impl(hb_font_t * font,const char * fmt,va_list ap)1813 hb_buffer_t::message_impl (hb_font_t *font, const char *fmt, va_list ap)
1814 {
1815   char buf[100];
1816   vsnprintf (buf, sizeof (buf),  fmt, ap);
1817   return (bool) this->message_func (this, font, buf, this->message_data);
1818 }
1819