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1 /*
2  * Copyright © 1998-2004  David Turner and Werner Lemberg
3  * Copyright © 2004,2007,2009  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 #if !defined(HB_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
31 #error "Include <hb.h> instead."
32 #endif
33 
34 #ifndef HB_BUFFER_H
35 #define HB_BUFFER_H
36 
37 #include "hb-common.h"
38 #include "hb-unicode.h"
39 #include "hb-font.h"
40 
41 HB_BEGIN_DECLS
42 
43 /**
44  * hb_glyph_info_t:
45  * @codepoint: either a Unicode code point (before shaping) or a glyph index
46  *             (after shaping).
47  * @cluster: the index of the character in the original text that corresponds
48  *           to this #hb_glyph_info_t, or whatever the client passes to
49  *           hb_buffer_add(). More than one #hb_glyph_info_t can have the same
50  *           @cluster value, if they resulted from the same character (e.g. one
51  *           to many glyph substitution), and when more than one character gets
52  *           merged in the same glyph (e.g. many to one glyph substitution) the
53  *           #hb_glyph_info_t will have the smallest cluster value of them.
54  *           By default some characters are merged into the same cluster
55  *           (e.g. combining marks have the same cluster as their bases)
56  *           even if they are separate glyphs, hb_buffer_set_cluster_level()
57  *           allow selecting more fine-grained cluster handling.
58  *
59  * The #hb_glyph_info_t is the structure that holds information about the
60  * glyphs and their relation to input text.
61  */
62 typedef struct hb_glyph_info_t {
63   hb_codepoint_t codepoint;
64   /*< private >*/
65   hb_mask_t      mask;
66   /*< public >*/
67   uint32_t       cluster;
68 
69   /*< private >*/
70   hb_var_int_t   var1;
71   hb_var_int_t   var2;
72 } hb_glyph_info_t;
73 
74 /**
75  * hb_glyph_flags_t:
76  * @HB_GLYPH_FLAG_UNSAFE_TO_BREAK: Indicates that if input text is broken at the
77  * 				   beginning of the cluster this glyph is part of,
78  * 				   then both sides need to be re-shaped, as the
79  * 				   result might be different.  On the flip side,
80  * 				   it means that when this flag is not present,
81  * 				   then it's safe to break the glyph-run at the
82  * 				   beginning of this cluster, and the two sides
83  * 				   represent the exact same result one would get
84  * 				   if breaking input text at the beginning of
85  * 				   this cluster and shaping the two sides
86  * 				   separately.  This can be used to optimize
87  * 				   paragraph layout, by avoiding re-shaping
88  * 				   of each line after line-breaking, or limiting
89  * 				   the reshaping to a small piece around the
90  * 				   breaking point only.
91  * @HB_GLYPH_FLAG_DEFINED: All the currently defined flags.
92  *
93  * Flags for #hb_glyph_info_t.
94  *
95  * Since: 1.5.0
96  */
97 typedef enum { /*< flags >*/
98   HB_GLYPH_FLAG_UNSAFE_TO_BREAK		= 0x00000001,
99 
100   HB_GLYPH_FLAG_DEFINED			= 0x00000001 /* OR of all defined flags */
101 } hb_glyph_flags_t;
102 
103 HB_EXTERN hb_glyph_flags_t
104 hb_glyph_info_get_glyph_flags (const hb_glyph_info_t *info);
105 
106 #define hb_glyph_info_get_glyph_flags(info) \
107 	((hb_glyph_flags_t) ((unsigned int) (info)->mask & HB_GLYPH_FLAG_DEFINED))
108 
109 
110 /**
111  * hb_glyph_position_t:
112  * @x_advance: how much the line advances after drawing this glyph when setting
113  *             text in horizontal direction.
114  * @y_advance: how much the line advances after drawing this glyph when setting
115  *             text in vertical direction.
116  * @x_offset: how much the glyph moves on the X-axis before drawing it, this
117  *            should not affect how much the line advances.
118  * @y_offset: how much the glyph moves on the Y-axis before drawing it, this
119  *            should not affect how much the line advances.
120  *
121  * The #hb_glyph_position_t is the structure that holds the positions of the
122  * glyph in both horizontal and vertical directions. All positions in
123  * #hb_glyph_position_t are relative to the current point.
124  *
125  */
126 typedef struct hb_glyph_position_t {
127   hb_position_t  x_advance;
128   hb_position_t  y_advance;
129   hb_position_t  x_offset;
130   hb_position_t  y_offset;
131 
132   /*< private >*/
133   hb_var_int_t   var;
134 } hb_glyph_position_t;
135 
136 /**
137  * hb_segment_properties_t:
138  * @direction: the #hb_direction_t of the buffer, see hb_buffer_set_direction().
139  * @script: the #hb_script_t of the buffer, see hb_buffer_set_script().
140  * @language: the #hb_language_t of the buffer, see hb_buffer_set_language().
141  *
142  * The structure that holds various text properties of an #hb_buffer_t. Can be
143  * set and retrieved using hb_buffer_set_segment_properties() and
144  * hb_buffer_get_segment_properties(), respectively.
145  */
146 typedef struct hb_segment_properties_t {
147   hb_direction_t  direction;
148   hb_script_t     script;
149   hb_language_t   language;
150   /*< private >*/
151   void           *reserved1;
152   void           *reserved2;
153 } hb_segment_properties_t;
154 
155 /**
156  * HB_SEGMENT_PROPERTIES_DEFAULT:
157  *
158  * The default #hb_segment_properties_t of of freshly created #hb_buffer_t.
159  */
160 #define HB_SEGMENT_PROPERTIES_DEFAULT {HB_DIRECTION_INVALID, \
161 				       HB_SCRIPT_INVALID, \
162 				       HB_LANGUAGE_INVALID, \
163 				       (void *) 0, \
164 				       (void *) 0}
165 
166 HB_EXTERN hb_bool_t
167 hb_segment_properties_equal (const hb_segment_properties_t *a,
168 			     const hb_segment_properties_t *b);
169 
170 HB_EXTERN unsigned int
171 hb_segment_properties_hash (const hb_segment_properties_t *p);
172 
173 
174 
175 /**
176  * hb_buffer_t:
177  *
178  * The main structure holding the input text and its properties before shaping,
179  * and output glyphs and their information after shaping.
180  */
181 
182 typedef struct hb_buffer_t hb_buffer_t;
183 
184 HB_EXTERN hb_buffer_t *
185 hb_buffer_create (void);
186 
187 HB_EXTERN hb_buffer_t *
188 hb_buffer_get_empty (void);
189 
190 HB_EXTERN hb_buffer_t *
191 hb_buffer_reference (hb_buffer_t *buffer);
192 
193 HB_EXTERN void
194 hb_buffer_destroy (hb_buffer_t *buffer);
195 
196 HB_EXTERN hb_bool_t
197 hb_buffer_set_user_data (hb_buffer_t        *buffer,
198 			 hb_user_data_key_t *key,
199 			 void *              data,
200 			 hb_destroy_func_t   destroy,
201 			 hb_bool_t           replace);
202 
203 HB_EXTERN void *
204 hb_buffer_get_user_data (hb_buffer_t        *buffer,
205 			 hb_user_data_key_t *key);
206 
207 
208 /**
209  * hb_buffer_content_type_t:
210  * @HB_BUFFER_CONTENT_TYPE_INVALID: Initial value for new buffer.
211  * @HB_BUFFER_CONTENT_TYPE_UNICODE: The buffer contains input characters (before shaping).
212  * @HB_BUFFER_CONTENT_TYPE_GLYPHS: The buffer contains output glyphs (after shaping).
213  *
214  * The type of #hb_buffer_t contents.
215  */
216 typedef enum {
217   HB_BUFFER_CONTENT_TYPE_INVALID = 0,
218   HB_BUFFER_CONTENT_TYPE_UNICODE,
219   HB_BUFFER_CONTENT_TYPE_GLYPHS
220 } hb_buffer_content_type_t;
221 
222 HB_EXTERN void
223 hb_buffer_set_content_type (hb_buffer_t              *buffer,
224 			    hb_buffer_content_type_t  content_type);
225 
226 HB_EXTERN hb_buffer_content_type_t
227 hb_buffer_get_content_type (hb_buffer_t *buffer);
228 
229 
230 HB_EXTERN void
231 hb_buffer_set_unicode_funcs (hb_buffer_t        *buffer,
232 			     hb_unicode_funcs_t *unicode_funcs);
233 
234 HB_EXTERN hb_unicode_funcs_t *
235 hb_buffer_get_unicode_funcs (hb_buffer_t        *buffer);
236 
237 HB_EXTERN void
238 hb_buffer_set_direction (hb_buffer_t    *buffer,
239 			 hb_direction_t  direction);
240 
241 HB_EXTERN hb_direction_t
242 hb_buffer_get_direction (hb_buffer_t *buffer);
243 
244 HB_EXTERN void
245 hb_buffer_set_script (hb_buffer_t *buffer,
246 		      hb_script_t  script);
247 
248 HB_EXTERN hb_script_t
249 hb_buffer_get_script (hb_buffer_t *buffer);
250 
251 HB_EXTERN void
252 hb_buffer_set_language (hb_buffer_t   *buffer,
253 			hb_language_t  language);
254 
255 
256 HB_EXTERN hb_language_t
257 hb_buffer_get_language (hb_buffer_t *buffer);
258 
259 HB_EXTERN void
260 hb_buffer_set_segment_properties (hb_buffer_t *buffer,
261 				  const hb_segment_properties_t *props);
262 
263 HB_EXTERN void
264 hb_buffer_get_segment_properties (hb_buffer_t *buffer,
265 				  hb_segment_properties_t *props);
266 
267 HB_EXTERN void
268 hb_buffer_guess_segment_properties (hb_buffer_t *buffer);
269 
270 
271 /**
272  * hb_buffer_flags_t:
273  * @HB_BUFFER_FLAG_DEFAULT: the default buffer flag.
274  * @HB_BUFFER_FLAG_BOT: flag indicating that special handling of the beginning
275  *                      of text paragraph can be applied to this buffer. Should usually
276  *                      be set, unless you are passing to the buffer only part
277  *                      of the text without the full context.
278  * @HB_BUFFER_FLAG_EOT: flag indicating that special handling of the end of text
279  *                      paragraph can be applied to this buffer, similar to
280  *                      @HB_BUFFER_FLAG_BOT.
281  * @HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES:
282  *                      flag indication that character with Default_Ignorable
283  *                      Unicode property should use the corresponding glyph
284  *                      from the font, instead of hiding them (done by
285  *                      replacing them with the space glyph and zeroing the
286  *                      advance width.)  This flag takes precedence over
287  *                      @HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES.
288  * @HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES:
289  *                      flag indication that character with Default_Ignorable
290  *                      Unicode property should be removed from glyph string
291  *                      instead of hiding them (done by replacing them with the
292  *                      space glyph and zeroing the advance width.)
293  *                      @HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES takes
294  *                      precedence over this flag. Since: 1.8.0
295  * @HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE:
296  *                      flag indicating that a dotted circle should
297  *                      not be inserted in the rendering of incorrect
298  *                      character sequences (such at <0905 093E>). Since: 2.4
299  *
300  * Flags for #hb_buffer_t.
301  *
302  * Since: 0.9.20
303  */
304 typedef enum { /*< flags >*/
305   HB_BUFFER_FLAG_DEFAULT			= 0x00000000u,
306   HB_BUFFER_FLAG_BOT				= 0x00000001u, /* Beginning-of-text */
307   HB_BUFFER_FLAG_EOT				= 0x00000002u, /* End-of-text */
308   HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES	= 0x00000004u,
309   HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES	= 0x00000008u,
310   HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE	= 0x00000010u,
311   HB_BUFFER_FLAG_PRODUCE_UNSAFE_TO_CONCAT = 0x00000040u
312 } hb_buffer_flags_t;
313 
314 HB_EXTERN void
315 hb_buffer_set_flags (hb_buffer_t       *buffer,
316 		     hb_buffer_flags_t  flags);
317 
318 HB_EXTERN hb_buffer_flags_t
319 hb_buffer_get_flags (hb_buffer_t *buffer);
320 
321 /**
322  * hb_buffer_cluster_level_t:
323  * @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES: Return cluster values grouped by graphemes into
324  *   monotone order.
325  * @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS: Return cluster values grouped into monotone order.
326  * @HB_BUFFER_CLUSTER_LEVEL_CHARACTERS: Don't group cluster values.
327  * @HB_BUFFER_CLUSTER_LEVEL_DEFAULT: Default cluster level,
328  *   equal to @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES.
329  *
330  * Data type for holding HarfBuzz's clustering behavior options. The cluster level
331  * dictates one aspect of how HarfBuzz will treat non-base characters
332  * during shaping.
333  *
334  * In @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES, non-base
335  * characters are merged into the cluster of the base character that precedes them.
336  *
337  * In @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS, non-base characters are initially
338  * assigned their own cluster values, which are not merged into preceding base
339  * clusters. This allows HarfBuzz to perform additional operations like reorder
340  * sequences of adjacent marks.
341  *
342  * @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES is the default, because it maintains
343  * backward compatibility with older versions of HarfBuzz. New client programs that
344  * do not need to maintain such backward compatibility are recommended to use
345  * @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS instead of the default.
346  *
347  * Since: 0.9.42
348  */
349 typedef enum {
350   HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES	= 0,
351   HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS	= 1,
352   HB_BUFFER_CLUSTER_LEVEL_CHARACTERS		= 2,
353   HB_BUFFER_CLUSTER_LEVEL_DEFAULT = HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES
354 } hb_buffer_cluster_level_t;
355 
356 HB_EXTERN void
357 hb_buffer_set_cluster_level (hb_buffer_t               *buffer,
358 			     hb_buffer_cluster_level_t  cluster_level);
359 
360 HB_EXTERN hb_buffer_cluster_level_t
361 hb_buffer_get_cluster_level (hb_buffer_t *buffer);
362 
363 /**
364  * HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT:
365  *
366  * The default code point for replacing invalid characters in a given encoding.
367  * Set to U+FFFD REPLACEMENT CHARACTER.
368  *
369  * Since: 0.9.31
370  */
371 #define HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT 0xFFFDu
372 
373 HB_EXTERN void
374 hb_buffer_set_replacement_codepoint (hb_buffer_t    *buffer,
375 				     hb_codepoint_t  replacement);
376 
377 HB_EXTERN hb_codepoint_t
378 hb_buffer_get_replacement_codepoint (hb_buffer_t    *buffer);
379 
380 HB_EXTERN void
381 hb_buffer_set_invisible_glyph (hb_buffer_t    *buffer,
382 			       hb_codepoint_t  invisible);
383 
384 HB_EXTERN hb_codepoint_t
385 hb_buffer_get_invisible_glyph (hb_buffer_t    *buffer);
386 
387 HB_EXTERN void
388 hb_buffer_set_not_found_glyph (hb_buffer_t    *buffer,
389 			       hb_codepoint_t  not_found);
390 
391 HB_EXTERN hb_codepoint_t
392 hb_buffer_get_not_found_glyph (hb_buffer_t    *buffer);
393 
394 
395 HB_EXTERN void
396 hb_buffer_reset (hb_buffer_t *buffer);
397 
398 HB_EXTERN void
399 hb_buffer_clear_contents (hb_buffer_t *buffer);
400 
401 HB_EXTERN hb_bool_t
402 hb_buffer_pre_allocate (hb_buffer_t  *buffer,
403 			unsigned int  size);
404 
405 
406 HB_EXTERN hb_bool_t
407 hb_buffer_allocation_successful (hb_buffer_t  *buffer);
408 
409 HB_EXTERN void
410 hb_buffer_reverse (hb_buffer_t *buffer);
411 
412 HB_EXTERN void
413 hb_buffer_reverse_range (hb_buffer_t *buffer,
414 			 unsigned int start, unsigned int end);
415 
416 HB_EXTERN void
417 hb_buffer_reverse_clusters (hb_buffer_t *buffer);
418 
419 
420 /* Filling the buffer in */
421 
422 HB_EXTERN void
423 hb_buffer_add (hb_buffer_t    *buffer,
424 	       hb_codepoint_t  codepoint,
425 	       unsigned int    cluster);
426 
427 HB_EXTERN void
428 hb_buffer_add_utf8 (hb_buffer_t  *buffer,
429 		    const char   *text,
430 		    int           text_length,
431 		    unsigned int  item_offset,
432 		    int           item_length);
433 
434 HB_EXTERN void
435 hb_buffer_add_utf16 (hb_buffer_t    *buffer,
436 		     const uint16_t *text,
437 		     int             text_length,
438 		     unsigned int    item_offset,
439 		     int             item_length);
440 
441 HB_EXTERN void
442 hb_buffer_add_utf32 (hb_buffer_t    *buffer,
443 		     const uint32_t *text,
444 		     int             text_length,
445 		     unsigned int    item_offset,
446 		     int             item_length);
447 
448 HB_EXTERN void
449 hb_buffer_add_latin1 (hb_buffer_t   *buffer,
450 		      const uint8_t *text,
451 		      int            text_length,
452 		      unsigned int   item_offset,
453 		      int            item_length);
454 
455 HB_EXTERN void
456 hb_buffer_add_codepoints (hb_buffer_t          *buffer,
457 			  const hb_codepoint_t *text,
458 			  int                   text_length,
459 			  unsigned int          item_offset,
460 			  int                   item_length);
461 
462 HB_EXTERN void
463 hb_buffer_append (hb_buffer_t *buffer,
464 		  hb_buffer_t *source,
465 		  unsigned int start,
466 		  unsigned int end);
467 
468 HB_EXTERN hb_bool_t
469 hb_buffer_set_length (hb_buffer_t  *buffer,
470 		      unsigned int  length);
471 
472 HB_EXTERN unsigned int
473 hb_buffer_get_length (hb_buffer_t *buffer);
474 
475 /* Getting glyphs out of the buffer */
476 
477 HB_EXTERN hb_glyph_info_t *
478 hb_buffer_get_glyph_infos (hb_buffer_t  *buffer,
479 			   unsigned int *length);
480 
481 HB_EXTERN hb_glyph_position_t *
482 hb_buffer_get_glyph_positions (hb_buffer_t  *buffer,
483 			       unsigned int *length);
484 
485 HB_EXTERN hb_bool_t
486 hb_buffer_has_positions (hb_buffer_t  *buffer);
487 
488 
489 HB_EXTERN void
490 hb_buffer_normalize_glyphs (hb_buffer_t *buffer);
491 
492 
493 /*
494  * Serialize
495  */
496 
497 /**
498  * hb_buffer_serialize_flags_t:
499  * @HB_BUFFER_SERIALIZE_FLAG_DEFAULT: serialize glyph names, clusters and positions.
500  * @HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS: do not serialize glyph cluster.
501  * @HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS: do not serialize glyph position information.
502  * @HB_BUFFER_SERIALIZE_FLAG_NO_GLYPH_NAMES: do no serialize glyph name.
503  * @HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS: serialize glyph extents.
504  * @HB_BUFFER_SERIALIZE_FLAG_GLYPH_FLAGS: serialize glyph flags. Since: 1.5.0
505  * @HB_BUFFER_SERIALIZE_FLAG_NO_ADVANCES: do not serialize glyph advances,
506  *  glyph offsets will reflect absolute glyph positions. Since: 1.8.0
507  *
508  * Flags that control what glyph information are serialized in hb_buffer_serialize_glyphs().
509  *
510  * Since: 0.9.20
511  */
512 typedef enum { /*< flags >*/
513   HB_BUFFER_SERIALIZE_FLAG_DEFAULT		= 0x00000000u,
514   HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS		= 0x00000001u,
515   HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS		= 0x00000002u,
516   HB_BUFFER_SERIALIZE_FLAG_NO_GLYPH_NAMES	= 0x00000004u,
517   HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS	= 0x00000008u,
518   HB_BUFFER_SERIALIZE_FLAG_GLYPH_FLAGS		= 0x00000010u,
519   HB_BUFFER_SERIALIZE_FLAG_NO_ADVANCES		= 0x00000020u
520 } hb_buffer_serialize_flags_t;
521 
522 /**
523  * hb_buffer_serialize_format_t:
524  * @HB_BUFFER_SERIALIZE_FORMAT_TEXT: a human-readable, plain text format.
525  * @HB_BUFFER_SERIALIZE_FORMAT_JSON: a machine-readable JSON format.
526  * @HB_BUFFER_SERIALIZE_FORMAT_INVALID: invalid format.
527  *
528  * The buffer serialization and de-serialization format used in
529  * hb_buffer_serialize_glyphs() and hb_buffer_deserialize_glyphs().
530  *
531  * Since: 0.9.2
532  */
533 typedef enum {
534   HB_BUFFER_SERIALIZE_FORMAT_TEXT	= HB_TAG('T','E','X','T'),
535   HB_BUFFER_SERIALIZE_FORMAT_JSON	= HB_TAG('J','S','O','N'),
536   HB_BUFFER_SERIALIZE_FORMAT_INVALID	= HB_TAG_NONE
537 } hb_buffer_serialize_format_t;
538 
539 HB_EXTERN hb_buffer_serialize_format_t
540 hb_buffer_serialize_format_from_string (const char *str, int len);
541 
542 HB_EXTERN const char *
543 hb_buffer_serialize_format_to_string (hb_buffer_serialize_format_t format);
544 
545 HB_EXTERN const char **
546 hb_buffer_serialize_list_formats (void);
547 
548 HB_EXTERN unsigned int
549 hb_buffer_serialize_glyphs (hb_buffer_t *buffer,
550 			    unsigned int start,
551 			    unsigned int end,
552 			    char *buf,
553 			    unsigned int buf_size,
554 			    unsigned int *buf_consumed,
555 			    hb_font_t *font,
556 			    hb_buffer_serialize_format_t format,
557 			    hb_buffer_serialize_flags_t flags);
558 
559 HB_EXTERN unsigned int
560 hb_buffer_serialize_unicode (hb_buffer_t *buffer,
561 					unsigned int start,
562 					unsigned int end,
563 					char *buf,
564 					unsigned int buf_size,
565 					unsigned int *buf_consumed,
566 					hb_buffer_serialize_format_t format,
567 					hb_buffer_serialize_flags_t flags);
568 
569 HB_EXTERN unsigned int
570 hb_buffer_serialize (hb_buffer_t *buffer,
571 					unsigned int start,
572 					unsigned int end,
573 					char *buf,
574 					unsigned int buf_size,
575 					unsigned int *buf_consumed,
576 					hb_font_t *font,
577 					hb_buffer_serialize_format_t format,
578 					hb_buffer_serialize_flags_t flags);
579 
580 HB_EXTERN hb_bool_t
581 hb_buffer_deserialize_glyphs (hb_buffer_t *buffer,
582 			      const char *buf,
583 			      int buf_len,
584 			      const char **end_ptr,
585 			      hb_font_t *font,
586 			      hb_buffer_serialize_format_t format);
587 
588 HB_EXTERN hb_bool_t
589 hb_buffer_deserialize_unicode (hb_buffer_t *buffer,
590             const char *buf,
591             int buf_len,
592             const char **end_ptr,
593             hb_buffer_serialize_format_t format);
594 
595 
596 
597 /*
598  * Compare buffers
599  */
600 
601 /**
602  * hb_buffer_diff_flags_t:
603  * @HB_BUFFER_DIFF_FLAG_EQUAL: equal buffers.
604  * @HB_BUFFER_DIFF_FLAG_CONTENT_TYPE_MISMATCH: buffers with different
605  *     #hb_buffer_content_type_t.
606  * @HB_BUFFER_DIFF_FLAG_LENGTH_MISMATCH: buffers with differing length.
607  * @HB_BUFFER_DIFF_FLAG_NOTDEF_PRESENT: `.notdef` glyph is present in the
608  *     reference buffer.
609  * @HB_BUFFER_DIFF_FLAG_DOTTED_CIRCLE_PRESENT: dotted circle glyph is present
610  *     in the reference buffer.
611  * @HB_BUFFER_DIFF_FLAG_CODEPOINT_MISMATCH: difference in #hb_glyph_info_t.codepoint
612  * @HB_BUFFER_DIFF_FLAG_CLUSTER_MISMATCH: difference in #hb_glyph_info_t.cluster
613  * @HB_BUFFER_DIFF_FLAG_GLYPH_FLAGS_MISMATCH: difference in #hb_glyph_flags_t.
614  * @HB_BUFFER_DIFF_FLAG_POSITION_MISMATCH: difference in #hb_glyph_position_t.
615  *
616  * Flags from comparing two #hb_buffer_t's.
617  *
618  * Buffer with different #hb_buffer_content_type_t cannot be meaningfully
619  * compared in any further detail.
620  *
621  * For buffers with differing length, the per-glyph comparison is not
622  * attempted, though we do still scan reference buffer for dotted circle and
623  * `.notdef` glyphs.
624  *
625  * If the buffers have the same length, we compare them glyph-by-glyph and
626  * report which aspect(s) of the glyph info/position are different.
627  *
628  * Since: 1.5.0
629  */
630 typedef enum { /*< flags >*/
631   HB_BUFFER_DIFF_FLAG_EQUAL			= 0x0000,
632 
633   /* Buffers with different content_type cannot be meaningfully compared
634    * in any further detail. */
635   HB_BUFFER_DIFF_FLAG_CONTENT_TYPE_MISMATCH	= 0x0001,
636 
637   /* For buffers with differing length, the per-glyph comparison is not
638    * attempted, though we do still scan reference for dottedcircle / .notdef
639    * glyphs. */
640   HB_BUFFER_DIFF_FLAG_LENGTH_MISMATCH		= 0x0002,
641 
642   /* We want to know if dottedcircle / .notdef glyphs are present in the
643    * reference, as we may not care so much about other differences in this
644    * case. */
645   HB_BUFFER_DIFF_FLAG_NOTDEF_PRESENT		= 0x0004,
646   HB_BUFFER_DIFF_FLAG_DOTTED_CIRCLE_PRESENT	= 0x0008,
647 
648   /* If the buffers have the same length, we compare them glyph-by-glyph
649    * and report which aspect(s) of the glyph info/position are different. */
650   HB_BUFFER_DIFF_FLAG_CODEPOINT_MISMATCH	= 0x0010,
651   HB_BUFFER_DIFF_FLAG_CLUSTER_MISMATCH		= 0x0020,
652   HB_BUFFER_DIFF_FLAG_GLYPH_FLAGS_MISMATCH	= 0x0040,
653   HB_BUFFER_DIFF_FLAG_POSITION_MISMATCH		= 0x0080
654 
655 } hb_buffer_diff_flags_t;
656 
657 /* Compare the contents of two buffers, report types of differences. */
658 HB_EXTERN hb_buffer_diff_flags_t
659 hb_buffer_diff (hb_buffer_t *buffer,
660 		hb_buffer_t *reference,
661 		hb_codepoint_t dottedcircle_glyph,
662 		unsigned int position_fuzz);
663 
664 
665 /*
666  * Debugging.
667  */
668 
669 /**
670  * hb_buffer_message_func_t:
671  * @buffer: An #hb_buffer_t to work upon
672  * @font: The #hb_font_t the @buffer is shaped with
673  * @message: %NULL-terminated message passed to the function
674  * @user_data: User data pointer passed by the caller
675  *
676  * A callback method for #hb_buffer_t. The method gets called with the
677  * #hb_buffer_t it was set on, the #hb_font_t the buffer is shaped with and a
678  * message describing what step of the shaping process will be performed.
679  * Returning %false from this method will skip this shaping step and move to
680  * the next one.
681  *
682  * Return value: %true to perform the shaping step, %false to skip it.
683  *
684  * Since: 1.1.3
685  */
686 typedef hb_bool_t	(*hb_buffer_message_func_t)	(hb_buffer_t *buffer,
687 							 hb_font_t   *font,
688 							 const char  *message,
689 							 void        *user_data);
690 
691 HB_EXTERN void
692 hb_buffer_set_message_func (hb_buffer_t *buffer,
693 			    hb_buffer_message_func_t func,
694 			    void *user_data, hb_destroy_func_t destroy);
695 
696 
697 HB_END_DECLS
698 
699 #endif /* HB_BUFFER_H */
700