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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 #ifndef HB_BUFFER_HH
31 #define HB_BUFFER_HH
32 
33 #include "hb.hh"
34 #include "hb-unicode.hh"
35 #include "hb-set-digest.hh"
36 
37 
38 #ifndef HB_BUFFER_MAX_LEN_FACTOR
39 #define HB_BUFFER_MAX_LEN_FACTOR 64
40 #endif
41 #ifndef HB_BUFFER_MAX_LEN_MIN
42 #define HB_BUFFER_MAX_LEN_MIN 16384
43 #endif
44 #ifndef HB_BUFFER_MAX_LEN_DEFAULT
45 #define HB_BUFFER_MAX_LEN_DEFAULT 0x3FFFFFFF /* Shaping more than a billion chars? Let us know! */
46 #endif
47 
48 #ifndef HB_BUFFER_MAX_OPS_FACTOR
49 #define HB_BUFFER_MAX_OPS_FACTOR 1024
50 #endif
51 #ifndef HB_BUFFER_MAX_OPS_MIN
52 #define HB_BUFFER_MAX_OPS_MIN 16384
53 #endif
54 #ifndef HB_BUFFER_MAX_OPS_DEFAULT
55 #define HB_BUFFER_MAX_OPS_DEFAULT 0x1FFFFFFF /* Shaping more than a billion operations? Let us know! */
56 #endif
57 
58 static_assert ((sizeof (hb_glyph_info_t) == 20), "");
59 static_assert ((sizeof (hb_glyph_info_t) == sizeof (hb_glyph_position_t)), "");
60 
61 HB_MARK_AS_FLAG_T (hb_glyph_flags_t);
62 HB_MARK_AS_FLAG_T (hb_buffer_flags_t);
63 HB_MARK_AS_FLAG_T (hb_buffer_serialize_flags_t);
64 HB_MARK_AS_FLAG_T (hb_buffer_diff_flags_t);
65 
66 enum hb_buffer_scratch_flags_t {
67   HB_BUFFER_SCRATCH_FLAG_DEFAULT			= 0x00000000u,
68   HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII			= 0x00000001u,
69   HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES		= 0x00000002u,
70   HB_BUFFER_SCRATCH_FLAG_HAS_SPACE_FALLBACK		= 0x00000004u,
71   HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT		= 0x00000008u,
72   HB_BUFFER_SCRATCH_FLAG_HAS_CGJ			= 0x00000010u,
73   HB_BUFFER_SCRATCH_FLAG_HAS_GLYPH_FLAGS		= 0x00000020u,
74   HB_BUFFER_SCRATCH_FLAG_HAS_BROKEN_SYLLABLE		= 0x00000040u,
75 
76   /* Reserved for shapers' internal use. */
77   HB_BUFFER_SCRATCH_FLAG_SHAPER0			= 0x01000000u,
78   HB_BUFFER_SCRATCH_FLAG_SHAPER1			= 0x02000000u,
79   HB_BUFFER_SCRATCH_FLAG_SHAPER2			= 0x04000000u,
80   HB_BUFFER_SCRATCH_FLAG_SHAPER3			= 0x08000000u,
81 };
82 HB_MARK_AS_FLAG_T (hb_buffer_scratch_flags_t);
83 
84 
85 /*
86  * hb_buffer_t
87  */
88 
89 struct hb_buffer_t
90 {
91   hb_object_header_t header;
92 
93   /*
94    * Information about how the text in the buffer should be treated.
95    */
96 
97   hb_unicode_funcs_t *unicode; /* Unicode functions */
98   hb_buffer_flags_t flags; /* BOT / EOT / etc. */
99   hb_buffer_cluster_level_t cluster_level;
100   hb_codepoint_t replacement; /* U+FFFD or something else. */
101   hb_codepoint_t invisible; /* 0 or something else. */
102   hb_codepoint_t not_found; /* 0 or something else. */
103 
104   /*
105    * Buffer contents
106    */
107 
108   hb_buffer_content_type_t content_type;
109   hb_segment_properties_t props; /* Script, language, direction */
110 
111   bool successful; /* Allocations successful */
112   bool shaping_failed; /* Shaping failure */
113   bool have_output; /* Whether we have an output buffer going on */
114   bool have_positions; /* Whether we have positions */
115 
116   unsigned int idx; /* Cursor into ->info and ->pos arrays */
117   unsigned int len; /* Length of ->info and ->pos arrays */
118   unsigned int out_len; /* Length of ->out_info array if have_output */
119 
120   unsigned int allocated; /* Length of allocated arrays */
121   hb_glyph_info_t     *info;
122   hb_glyph_info_t     *out_info;
123   hb_glyph_position_t *pos;
124 
125   /* Text before / after the main buffer contents.
126    * Always in Unicode, and ordered outward.
127    * Index 0 is for "pre-context", 1 for "post-context". */
128   static constexpr unsigned CONTEXT_LENGTH = 5u;
129   hb_codepoint_t context[2][CONTEXT_LENGTH];
130   unsigned int context_len[2];
131 
132 
133   /*
134    * Managed by enter / leave
135    */
136 
137   uint8_t allocated_var_bits;
138   uint8_t serial;
139   hb_buffer_scratch_flags_t scratch_flags; /* Have space-fallback, etc. */
140   unsigned int max_len; /* Maximum allowed len. */
141   int max_ops; /* Maximum allowed operations. */
142   /* The bits here reflect current allocations of the bytes in glyph_info_t's var1 and var2. */
143 
144 
145   /*
146    * Messaging callback
147    */
148 
149 #ifndef HB_NO_BUFFER_MESSAGE
150   hb_buffer_message_func_t message_func;
151   void *message_data;
152   hb_destroy_func_t message_destroy;
153   unsigned message_depth; /* How deeply are we inside a message callback? */
154 #else
155   static constexpr unsigned message_depth = 0u;
156 #endif
157 
158 
159 
160   /* Methods */
161 
in_errorhb_buffer_t162   HB_NODISCARD bool in_error () const { return !successful; }
163 
allocate_varhb_buffer_t164   void allocate_var (unsigned int start, unsigned int count)
165   {
166     unsigned int end = start + count;
167     assert (end <= 8);
168     unsigned int bits = (1u<<end) - (1u<<start);
169     assert (0 == (allocated_var_bits & bits));
170     allocated_var_bits |= bits;
171   }
try_allocate_varhb_buffer_t172   bool try_allocate_var (unsigned int start, unsigned int count)
173   {
174     unsigned int end = start + count;
175     assert (end <= 8);
176     unsigned int bits = (1u<<end) - (1u<<start);
177     if (allocated_var_bits & bits)
178       return false;
179     allocated_var_bits |= bits;
180     return true;
181   }
deallocate_varhb_buffer_t182   void deallocate_var (unsigned int start, unsigned int count)
183   {
184     unsigned int end = start + count;
185     assert (end <= 8);
186     unsigned int bits = (1u<<end) - (1u<<start);
187     assert (bits == (allocated_var_bits & bits));
188     allocated_var_bits &= ~bits;
189   }
assert_varhb_buffer_t190   void assert_var (unsigned int start, unsigned int count)
191   {
192     unsigned int end = start + count;
193     assert (end <= 8);
194     HB_UNUSED unsigned int bits = (1u<<end) - (1u<<start);
195     assert (bits == (allocated_var_bits & bits));
196   }
deallocate_var_allhb_buffer_t197   void deallocate_var_all ()
198   {
199     allocated_var_bits = 0;
200   }
201 
curhb_buffer_t202   hb_glyph_info_t &cur (unsigned int i = 0) { return info[idx + i]; }
curhb_buffer_t203   hb_glyph_info_t cur (unsigned int i = 0) const { return info[idx + i]; }
204 
cur_poshb_buffer_t205   hb_glyph_position_t &cur_pos (unsigned int i = 0) { return pos[idx + i]; }
cur_poshb_buffer_t206   hb_glyph_position_t cur_pos (unsigned int i = 0) const { return pos[idx + i]; }
207 
prevhb_buffer_t208   hb_glyph_info_t &prev ()      { return out_info[out_len ? out_len - 1 : 0]; }
prevhb_buffer_t209   hb_glyph_info_t prev () const { return out_info[out_len ? out_len - 1 : 0]; }
210 
digesthb_buffer_t211   hb_set_digest_t digest () const
212   {
213     hb_set_digest_t d;
214     d.init ();
215     d.add_array (&info[0].codepoint, len, sizeof (info[0]));
216     return d;
217   }
218 
219   HB_INTERNAL void similar (const hb_buffer_t &src);
220   HB_INTERNAL void reset ();
221   HB_INTERNAL void clear ();
222 
223   /* Called around shape() */
224   HB_INTERNAL void enter ();
225   HB_INTERNAL void leave ();
226 
227 #ifndef HB_NO_BUFFER_VERIFY
228   HB_INTERNAL
229 #endif
230   bool verify (hb_buffer_t        *text_buffer,
231 	       hb_font_t          *font,
232 	       const hb_feature_t *features,
233 	       unsigned int        num_features,
234 	       const char * const *shapers)
235 #ifndef HB_NO_BUFFER_VERIFY
236   ;
237 #else
238   { return true; }
239 #endif
240 
backtrack_lenhb_buffer_t241   unsigned int backtrack_len () const { return have_output ? out_len : idx; }
lookahead_lenhb_buffer_t242   unsigned int lookahead_len () const { return len - idx; }
next_serialhb_buffer_t243   uint8_t next_serial () { return ++serial ? serial : ++serial; }
244 
245   HB_INTERNAL void add (hb_codepoint_t  codepoint,
246 			unsigned int    cluster);
247   HB_INTERNAL void add_info (const hb_glyph_info_t &glyph_info);
248 
reverse_rangehb_buffer_t249   void reverse_range (unsigned start, unsigned end)
250   {
251     hb_array_t<hb_glyph_info_t> (info, len).reverse (start, end);
252     if (have_positions)
253       hb_array_t<hb_glyph_position_t> (pos, len).reverse (start, end);
254   }
reversehb_buffer_t255   void reverse () { reverse_range (0, len); }
256 
257   template <typename FuncType>
reverse_groupshb_buffer_t258   void reverse_groups (const FuncType& group,
259 		       bool merge_clusters = false)
260   {
261     if (unlikely (!len))
262       return;
263 
264     unsigned start = 0;
265     unsigned i;
266     for (i = 1; i < len; i++)
267     {
268       if (!group (info[i - 1], info[i]))
269       {
270 	if (merge_clusters)
271 	  this->merge_clusters (start, i);
272 	reverse_range (start, i);
273 	start = i;
274       }
275     }
276     if (merge_clusters)
277       this->merge_clusters (start, i);
278     reverse_range (start, i);
279 
280     reverse ();
281   }
282 
283   template <typename FuncType>
group_endhb_buffer_t284   unsigned group_end (unsigned start, const FuncType& group) const
285   {
286     while (++start < len && group (info[start - 1], info[start]))
287       ;
288 
289     return start;
290   }
291 
_cluster_group_funchb_buffer_t292   static bool _cluster_group_func (const hb_glyph_info_t& a,
293 				   const hb_glyph_info_t& b)
294   { return a.cluster == b.cluster; }
295 
reverse_clustershb_buffer_t296   void reverse_clusters () { reverse_groups (_cluster_group_func); }
297 
298   HB_INTERNAL void guess_segment_properties ();
299 
300   HB_INTERNAL bool sync ();
301   HB_INTERNAL int sync_so_far ();
302   HB_INTERNAL void clear_output ();
303   HB_INTERNAL void clear_positions ();
304 
305   template <typename T>
replace_glyphshb_buffer_t306   HB_NODISCARD bool replace_glyphs (unsigned int num_in,
307 				    unsigned int num_out,
308 				    const T *glyph_data)
309   {
310     if (unlikely (!make_room_for (num_in, num_out))) return false;
311 
312     assert (idx + num_in <= len);
313 
314     merge_clusters (idx, idx + num_in);
315 
316     hb_glyph_info_t &orig_info = idx < len ? cur() : prev();
317 
318     hb_glyph_info_t *pinfo = &out_info[out_len];
319     for (unsigned int i = 0; i < num_out; i++)
320     {
321       *pinfo = orig_info;
322       pinfo->codepoint = glyph_data[i];
323       pinfo++;
324     }
325 
326     idx  += num_in;
327     out_len += num_out;
328     return true;
329   }
330 
replace_glyphhb_buffer_t331   HB_NODISCARD bool replace_glyph (hb_codepoint_t glyph_index)
332   { return replace_glyphs (1, 1, &glyph_index); }
333 
334   /* Makes a copy of the glyph at idx to output and replace glyph_index */
output_glyphhb_buffer_t335   HB_NODISCARD bool output_glyph (hb_codepoint_t glyph_index)
336   { return replace_glyphs (0, 1, &glyph_index); }
337 
output_infohb_buffer_t338   HB_NODISCARD bool output_info (const hb_glyph_info_t &glyph_info)
339   {
340     if (unlikely (!make_room_for (0, 1))) return false;
341 
342     out_info[out_len] = glyph_info;
343 
344     out_len++;
345     return true;
346   }
347   /* Copies glyph at idx to output but doesn't advance idx */
copy_glyphhb_buffer_t348   HB_NODISCARD bool copy_glyph ()
349   {
350     /* Extra copy because cur()'s return can be freed within
351      * output_info() call if buffer reallocates. */
352     return output_info (hb_glyph_info_t (cur()));
353   }
354 
355   /* Copies glyph at idx to output and advance idx.
356    * If there's no output, just advance idx. */
next_glyphhb_buffer_t357   HB_NODISCARD bool next_glyph ()
358   {
359     if (have_output)
360     {
361       if (out_info != info || out_len != idx)
362       {
363 	if (unlikely (!make_room_for (1, 1))) return false;
364 	out_info[out_len] = info[idx];
365       }
366       out_len++;
367     }
368 
369     idx++;
370     return true;
371   }
372   /* Copies n glyphs at idx to output and advance idx.
373    * If there's no output, just advance idx. */
next_glyphshb_buffer_t374   HB_NODISCARD bool next_glyphs (unsigned int n)
375   {
376     if (have_output)
377     {
378       if (out_info != info || out_len != idx)
379       {
380 	if (unlikely (!make_room_for (n, n))) return false;
381 	memmove (out_info + out_len, info + idx, n * sizeof (out_info[0]));
382       }
383       out_len += n;
384     }
385 
386     idx += n;
387     return true;
388   }
389   /* Advance idx without copying to output. */
skip_glyphhb_buffer_t390   void skip_glyph () { idx++; }
reset_maskshb_buffer_t391   void reset_masks (hb_mask_t mask)
392   {
393     for (unsigned int j = 0; j < len; j++)
394       info[j].mask = mask;
395   }
add_maskshb_buffer_t396   void add_masks (hb_mask_t mask)
397   {
398     for (unsigned int j = 0; j < len; j++)
399       info[j].mask |= mask;
400   }
401   HB_INTERNAL void set_masks (hb_mask_t value, hb_mask_t mask,
402 			      unsigned int cluster_start, unsigned int cluster_end);
403 
merge_clustershb_buffer_t404   void merge_clusters (unsigned int start, unsigned int end)
405   {
406     if (end - start < 2)
407       return;
408     merge_clusters_impl (start, end);
409   }
410   HB_INTERNAL void merge_clusters_impl (unsigned int start, unsigned int end);
411   HB_INTERNAL void merge_out_clusters (unsigned int start, unsigned int end);
412   /* Merge clusters for deleting current glyph, and skip it. */
413   HB_INTERNAL void delete_glyph ();
414   HB_INTERNAL void delete_glyphs_inplace (bool (*filter) (const hb_glyph_info_t *info));
415 
416 
417 
418   /* Adds glyph flags in mask to infos with clusters between start and end.
419    * The start index will be from out-buffer if from_out_buffer is true.
420    * If interior is true, then the cluster having the minimum value is skipped. */
_set_glyph_flagshb_buffer_t421   void _set_glyph_flags (hb_mask_t mask,
422 			 unsigned start = 0,
423 			 unsigned end = (unsigned) -1,
424 			 bool interior = false,
425 			 bool from_out_buffer = false)
426   {
427     end = hb_min (end, len);
428 
429     if (interior && !from_out_buffer && end - start < 2)
430       return;
431 
432     scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_GLYPH_FLAGS;
433 
434     if (!from_out_buffer || !have_output)
435     {
436       if (!interior)
437       {
438 	for (unsigned i = start; i < end; i++)
439 	  info[i].mask |= mask;
440       }
441       else
442       {
443 	unsigned cluster = _infos_find_min_cluster (info, start, end);
444 	_infos_set_glyph_flags (info, start, end, cluster, mask);
445       }
446     }
447     else
448     {
449       assert (start <= out_len);
450       assert (idx <= end);
451 
452       if (!interior)
453       {
454 	for (unsigned i = start; i < out_len; i++)
455 	  out_info[i].mask |= mask;
456 	for (unsigned i = idx; i < end; i++)
457 	  info[i].mask |= mask;
458       }
459       else
460       {
461 	unsigned cluster = _infos_find_min_cluster (info, idx, end);
462 	cluster = _infos_find_min_cluster (out_info, start, out_len, cluster);
463 
464 	_infos_set_glyph_flags (out_info, start, out_len, cluster, mask);
465 	_infos_set_glyph_flags (info, idx, end, cluster, mask);
466       }
467     }
468   }
469 
unsafe_to_breakhb_buffer_t470   void unsafe_to_break (unsigned int start = 0, unsigned int end = -1)
471   {
472     _set_glyph_flags (HB_GLYPH_FLAG_UNSAFE_TO_BREAK | HB_GLYPH_FLAG_UNSAFE_TO_CONCAT,
473 		      start, end,
474 		      true);
475   }
safe_to_insert_tatweelhb_buffer_t476   void safe_to_insert_tatweel (unsigned int start = 0, unsigned int end = -1)
477   {
478     if ((flags & HB_BUFFER_FLAG_PRODUCE_SAFE_TO_INSERT_TATWEEL) == 0)
479     {
480       unsafe_to_break (start, end);
481       return;
482     }
483     _set_glyph_flags (HB_GLYPH_FLAG_SAFE_TO_INSERT_TATWEEL,
484 		      start, end,
485 		      true);
486   }
unsafe_to_concathb_buffer_t487   void unsafe_to_concat (unsigned int start = 0, unsigned int end = -1)
488   {
489     if (likely ((flags & HB_BUFFER_FLAG_PRODUCE_UNSAFE_TO_CONCAT) == 0))
490       return;
491     _set_glyph_flags (HB_GLYPH_FLAG_UNSAFE_TO_CONCAT,
492 		      start, end,
493 		      true);
494   }
unsafe_to_break_from_outbufferhb_buffer_t495   void unsafe_to_break_from_outbuffer (unsigned int start = 0, unsigned int end = -1)
496   {
497     _set_glyph_flags (HB_GLYPH_FLAG_UNSAFE_TO_BREAK | HB_GLYPH_FLAG_UNSAFE_TO_CONCAT,
498 		      start, end,
499 		      true, true);
500   }
unsafe_to_concat_from_outbufferhb_buffer_t501   void unsafe_to_concat_from_outbuffer (unsigned int start = 0, unsigned int end = -1)
502   {
503     if (likely ((flags & HB_BUFFER_FLAG_PRODUCE_UNSAFE_TO_CONCAT) == 0))
504       return;
505     _set_glyph_flags (HB_GLYPH_FLAG_UNSAFE_TO_CONCAT,
506 		      start, end,
507 		      false, true);
508   }
509 
510 
511   /* Internal methods */
512   HB_NODISCARD HB_INTERNAL bool move_to (unsigned int i); /* i is output-buffer index. */
513 
514   HB_NODISCARD HB_INTERNAL bool enlarge (unsigned int size);
515 
ensurehb_buffer_t516   HB_NODISCARD bool ensure (unsigned int size)
517   { return likely (!size || size < allocated) ? true : enlarge (size); }
518 
ensure_inplacehb_buffer_t519   HB_NODISCARD bool ensure_inplace (unsigned int size)
520   { return likely (!size || size < allocated); }
521 
assert_glyphshb_buffer_t522   void assert_glyphs ()
523   {
524     assert ((content_type == HB_BUFFER_CONTENT_TYPE_GLYPHS) ||
525 	    (!len && (content_type == HB_BUFFER_CONTENT_TYPE_INVALID)));
526   }
assert_unicodehb_buffer_t527   void assert_unicode ()
528   {
529     assert ((content_type == HB_BUFFER_CONTENT_TYPE_UNICODE) ||
530 	    (!len && (content_type == HB_BUFFER_CONTENT_TYPE_INVALID)));
531   }
ensure_glyphshb_buffer_t532   HB_NODISCARD bool ensure_glyphs ()
533   {
534     if (unlikely (content_type != HB_BUFFER_CONTENT_TYPE_GLYPHS))
535     {
536       if (content_type != HB_BUFFER_CONTENT_TYPE_INVALID)
537 	return false;
538       assert (len == 0);
539       content_type = HB_BUFFER_CONTENT_TYPE_GLYPHS;
540     }
541     return true;
542   }
ensure_unicodehb_buffer_t543   HB_NODISCARD bool ensure_unicode ()
544   {
545     if (unlikely (content_type != HB_BUFFER_CONTENT_TYPE_UNICODE))
546     {
547       if (content_type != HB_BUFFER_CONTENT_TYPE_INVALID)
548 	return false;
549       assert (len == 0);
550       content_type = HB_BUFFER_CONTENT_TYPE_UNICODE;
551     }
552     return true;
553   }
554 
555   HB_NODISCARD HB_INTERNAL bool make_room_for (unsigned int num_in, unsigned int num_out);
556   HB_NODISCARD HB_INTERNAL bool shift_forward (unsigned int count);
557 
558   typedef long scratch_buffer_t;
559   HB_INTERNAL scratch_buffer_t *get_scratch_buffer (unsigned int *size);
560 
clear_contexthb_buffer_t561   void clear_context (unsigned int side) { context_len[side] = 0; }
562 
563   HB_INTERNAL void sort (unsigned int start, unsigned int end, int(*compar)(const hb_glyph_info_t *, const hb_glyph_info_t *));
564 
messaginghb_buffer_t565   bool messaging ()
566   {
567 #ifdef HB_NO_BUFFER_MESSAGE
568     return false;
569 #else
570     return unlikely (message_func);
571 #endif
572   }
messagehb_buffer_t573   bool message (hb_font_t *font, const char *fmt, ...) HB_PRINTF_FUNC(3, 4)
574   {
575 #ifdef HB_NO_BUFFER_MESSAGE
576    return true;
577 #else
578     if (likely (!messaging ()))
579       return true;
580 
581     va_list ap;
582     va_start (ap, fmt);
583     bool ret = message_impl (font, fmt, ap);
584     va_end (ap);
585 
586     return ret;
587 #endif
588   }
589   HB_INTERNAL bool message_impl (hb_font_t *font, const char *fmt, va_list ap) HB_PRINTF_FUNC(3, 0);
590 
591   static void
set_clusterhb_buffer_t592   set_cluster (hb_glyph_info_t &inf, unsigned int cluster, unsigned int mask = 0)
593   {
594     if (inf.cluster != cluster)
595       inf.mask = (inf.mask & ~HB_GLYPH_FLAG_DEFINED) | (mask & HB_GLYPH_FLAG_DEFINED);
596     inf.cluster = cluster;
597   }
598   void
_infos_set_glyph_flagshb_buffer_t599   _infos_set_glyph_flags (hb_glyph_info_t *infos,
600 			  unsigned int start, unsigned int end,
601 			  unsigned int cluster,
602 			  hb_mask_t mask)
603   {
604     for (unsigned int i = start; i < end; i++)
605       if (cluster != infos[i].cluster)
606       {
607 	scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_GLYPH_FLAGS;
608 	infos[i].mask |= mask;
609       }
610   }
611   static unsigned
_infos_find_min_clusterhb_buffer_t612   _infos_find_min_cluster (const hb_glyph_info_t *infos,
613 			   unsigned start, unsigned end,
614 			   unsigned cluster = UINT_MAX)
615   {
616     for (unsigned int i = start; i < end; i++)
617       cluster = hb_min (cluster, infos[i].cluster);
618     return cluster;
619   }
620 
clear_glyph_flagshb_buffer_t621   void clear_glyph_flags (hb_mask_t mask = 0)
622   {
623     for (unsigned int i = 0; i < len; i++)
624       info[i].mask = (info[i].mask & ~HB_GLYPH_FLAG_DEFINED) | (mask & HB_GLYPH_FLAG_DEFINED);
625   }
626 };
627 DECLARE_NULL_INSTANCE (hb_buffer_t);
628 
629 
630 #define foreach_group(buffer, start, end, group_func) \
631   for (unsigned int \
632        _count = buffer->len, \
633        start = 0, end = _count ? buffer->group_end (0, group_func) : 0; \
634        start < _count; \
635        start = end, end = buffer->group_end (start, group_func))
636 
637 #define foreach_cluster(buffer, start, end) \
638 	foreach_group (buffer, start, end, hb_buffer_t::_cluster_group_func)
639 
640 
641 #define HB_BUFFER_XALLOCATE_VAR(b, func, var) \
642   b->func (offsetof (hb_glyph_info_t, var) - offsetof(hb_glyph_info_t, var1), \
643 	   sizeof (b->info[0].var))
644 #define HB_BUFFER_ALLOCATE_VAR(b, var)		HB_BUFFER_XALLOCATE_VAR (b, allocate_var,     var ())
645 #define HB_BUFFER_TRY_ALLOCATE_VAR(b, var)	HB_BUFFER_XALLOCATE_VAR (b, try_allocate_var, var ())
646 #define HB_BUFFER_DEALLOCATE_VAR(b, var)	HB_BUFFER_XALLOCATE_VAR (b, deallocate_var,   var ())
647 #define HB_BUFFER_ASSERT_VAR(b, var)		HB_BUFFER_XALLOCATE_VAR (b, assert_var,       var ())
648 
649 
650 #endif /* HB_BUFFER_HH */
651