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.
80 * On the flip side, it means that when this
81 * flag is not present, then it is safe to break
82 * the glyph-run at the beginning of this
83 * cluster, and the two sides will represent the
84 * exact same result one would get if breaking
85 * input text at the beginning of this cluster
86 * and shaping the two sides separately.
87 * This can be used to optimize paragraph
88 * layout, by avoiding re-shaping of each line
89 * after line-breaking.
90 * @HB_GLYPH_FLAG_UNSAFE_TO_CONCAT: Indicates that if input text is changed on one
91 * side of the beginning of the cluster this glyph
92 * is part of, then the shaping results for the
93 * other side might change.
94 * Note that the absence of this flag will NOT by
95 * itself mean that it IS safe to concat text.
96 * Only two pieces of text both of which clear of
97 * this flag can be concatenated safely.
98 * This can be used to optimize paragraph
99 * layout, by avoiding re-shaping of each line
100 * after line-breaking, by limiting the
101 * reshaping to a small piece around the
102 * breaking position only, even if the breaking
103 * position carries the
104 * #HB_GLYPH_FLAG_UNSAFE_TO_BREAK or when
105 * hyphenation or other text transformation
106 * happens at line-break position, in the following
107 * way:
108 * 1. Iterate back from the line-break position
109 * until the first cluster start position that is
110 * NOT unsafe-to-concat, 2. shape the segment from
111 * there till the end of line, 3. check whether the
112 * resulting glyph-run also is clear of the
113 * unsafe-to-concat at its start-of-text position;
114 * if it is, just splice it into place and the line
115 * is shaped; If not, move on to a position further
116 * back that is clear of unsafe-to-concat and retry
117 * from there, and repeat.
118 * At the start of next line a similar algorithm can
119 * be implemented. That is: 1. Iterate forward from
120 * the line-break position until the first cluster
121 * start position that is NOT unsafe-to-concat, 2.
122 * shape the segment from beginning of the line to
123 * that position, 3. check whether the resulting
124 * glyph-run also is clear of the unsafe-to-concat
125 * at its end-of-text position; if it is, just splice
126 * it into place and the beginning is shaped; If not,
127 * move on to a position further forward that is clear
128 * of unsafe-to-concat and retry up to there, and repeat.
129 * A slight complication will arise in the
130 * implementation of the algorithm above,
131 * because while our buffer API has a way to
132 * return flags for position corresponding to
133 * start-of-text, there is currently no position
134 * corresponding to end-of-text. This limitation
135 * can be alleviated by shaping more text than needed
136 * and looking for unsafe-to-concat flag within text
137 * clusters.
138 * The #HB_GLYPH_FLAG_UNSAFE_TO_BREAK flag will
139 * always imply this flag.
140 * To use this flag, you must enable the buffer flag
141 * @HB_BUFFER_FLAG_PRODUCE_UNSAFE_TO_CONCAT during
142 * shaping, otherwise the buffer flag will not be
143 * reliably produced.
144 * Since: 4.0.0
145 * @HB_GLYPH_FLAG_SAFE_TO_INSERT_TATWEEL: In scripts that use elongation (Arabic,
146 Mongolian, Syriac, etc.), this flag signifies
147 that it is safe to insert a U+0640 TATWEEL
148 character before this cluster for elongation.
149 This flag does not determine the
150 script-specific elongation places, but only
151 when it is safe to do the elongation without
152 interrupting text shaping.
153 Since: 5.1.0
154 * @HB_GLYPH_FLAG_DEFINED: All the currently defined flags.
155 *
156 * Flags for #hb_glyph_info_t.
157 *
158 * Since: 1.5.0
159 */
160 typedef enum { /*< flags >*/
161 HB_GLYPH_FLAG_UNSAFE_TO_BREAK = 0x00000001,
162 HB_GLYPH_FLAG_UNSAFE_TO_CONCAT = 0x00000002,
163 HB_GLYPH_FLAG_SAFE_TO_INSERT_TATWEEL = 0x00000004,
164
165 HB_GLYPH_FLAG_DEFINED = 0x00000007 /* OR of all defined flags */
166 } hb_glyph_flags_t;
167
168 HB_EXTERN hb_glyph_flags_t
169 hb_glyph_info_get_glyph_flags (const hb_glyph_info_t *info);
170
171 #define hb_glyph_info_get_glyph_flags(info) \
172 ((hb_glyph_flags_t) ((unsigned int) (info)->mask & HB_GLYPH_FLAG_DEFINED))
173
174
175 /**
176 * hb_glyph_position_t:
177 * @x_advance: how much the line advances after drawing this glyph when setting
178 * text in horizontal direction.
179 * @y_advance: how much the line advances after drawing this glyph when setting
180 * text in vertical direction.
181 * @x_offset: how much the glyph moves on the X-axis before drawing it, this
182 * should not affect how much the line advances.
183 * @y_offset: how much the glyph moves on the Y-axis before drawing it, this
184 * should not affect how much the line advances.
185 *
186 * The #hb_glyph_position_t is the structure that holds the positions of the
187 * glyph in both horizontal and vertical directions. All positions in
188 * #hb_glyph_position_t are relative to the current point.
189 *
190 */
191 typedef struct hb_glyph_position_t {
192 hb_position_t x_advance;
193 hb_position_t y_advance;
194 hb_position_t x_offset;
195 hb_position_t y_offset;
196
197 /*< private >*/
198 hb_var_int_t var;
199 } hb_glyph_position_t;
200
201 /**
202 * hb_segment_properties_t:
203 * @direction: the #hb_direction_t of the buffer, see hb_buffer_set_direction().
204 * @script: the #hb_script_t of the buffer, see hb_buffer_set_script().
205 * @language: the #hb_language_t of the buffer, see hb_buffer_set_language().
206 *
207 * The structure that holds various text properties of an #hb_buffer_t. Can be
208 * set and retrieved using hb_buffer_set_segment_properties() and
209 * hb_buffer_get_segment_properties(), respectively.
210 */
211 typedef struct hb_segment_properties_t {
212 hb_direction_t direction;
213 hb_script_t script;
214 hb_language_t language;
215 /*< private >*/
216 void *reserved1;
217 void *reserved2;
218 } hb_segment_properties_t;
219
220 /**
221 * HB_SEGMENT_PROPERTIES_DEFAULT:
222 *
223 * The default #hb_segment_properties_t of of freshly created #hb_buffer_t.
224 */
225 #define HB_SEGMENT_PROPERTIES_DEFAULT {HB_DIRECTION_INVALID, \
226 HB_SCRIPT_INVALID, \
227 HB_LANGUAGE_INVALID, \
228 (void *) 0, \
229 (void *) 0}
230
231 HB_EXTERN hb_bool_t
232 hb_segment_properties_equal (const hb_segment_properties_t *a,
233 const hb_segment_properties_t *b);
234
235 HB_EXTERN unsigned int
236 hb_segment_properties_hash (const hb_segment_properties_t *p);
237
238 HB_EXTERN void
239 hb_segment_properties_overlay (hb_segment_properties_t *p,
240 const hb_segment_properties_t *src);
241
242
243 /**
244 * hb_buffer_t:
245 *
246 * The main structure holding the input text and its properties before shaping,
247 * and output glyphs and their information after shaping.
248 */
249
250 typedef struct hb_buffer_t hb_buffer_t;
251
252 HB_EXTERN hb_buffer_t *
253 hb_buffer_create (void);
254
255 HB_EXTERN hb_buffer_t *
256 hb_buffer_create_similar (const hb_buffer_t *src);
257
258 HB_EXTERN void
259 hb_buffer_reset (hb_buffer_t *buffer);
260
261
262 HB_EXTERN hb_buffer_t *
263 hb_buffer_get_empty (void);
264
265 HB_EXTERN hb_buffer_t *
266 hb_buffer_reference (hb_buffer_t *buffer);
267
268 HB_EXTERN void
269 hb_buffer_destroy (hb_buffer_t *buffer);
270
271 HB_EXTERN hb_bool_t
272 hb_buffer_set_user_data (hb_buffer_t *buffer,
273 hb_user_data_key_t *key,
274 void * data,
275 hb_destroy_func_t destroy,
276 hb_bool_t replace);
277
278 HB_EXTERN void *
279 hb_buffer_get_user_data (const hb_buffer_t *buffer,
280 hb_user_data_key_t *key);
281
282
283 /**
284 * hb_buffer_content_type_t:
285 * @HB_BUFFER_CONTENT_TYPE_INVALID: Initial value for new buffer.
286 * @HB_BUFFER_CONTENT_TYPE_UNICODE: The buffer contains input characters (before shaping).
287 * @HB_BUFFER_CONTENT_TYPE_GLYPHS: The buffer contains output glyphs (after shaping).
288 *
289 * The type of #hb_buffer_t contents.
290 */
291 typedef enum {
292 HB_BUFFER_CONTENT_TYPE_INVALID = 0,
293 HB_BUFFER_CONTENT_TYPE_UNICODE,
294 HB_BUFFER_CONTENT_TYPE_GLYPHS
295 } hb_buffer_content_type_t;
296
297 HB_EXTERN void
298 hb_buffer_set_content_type (hb_buffer_t *buffer,
299 hb_buffer_content_type_t content_type);
300
301 HB_EXTERN hb_buffer_content_type_t
302 hb_buffer_get_content_type (const hb_buffer_t *buffer);
303
304
305 HB_EXTERN void
306 hb_buffer_set_unicode_funcs (hb_buffer_t *buffer,
307 hb_unicode_funcs_t *unicode_funcs);
308
309 HB_EXTERN hb_unicode_funcs_t *
310 hb_buffer_get_unicode_funcs (const hb_buffer_t *buffer);
311
312 HB_EXTERN void
313 hb_buffer_set_direction (hb_buffer_t *buffer,
314 hb_direction_t direction);
315
316 HB_EXTERN hb_direction_t
317 hb_buffer_get_direction (const hb_buffer_t *buffer);
318
319 HB_EXTERN void
320 hb_buffer_set_script (hb_buffer_t *buffer,
321 hb_script_t script);
322
323 HB_EXTERN hb_script_t
324 hb_buffer_get_script (const hb_buffer_t *buffer);
325
326 HB_EXTERN void
327 hb_buffer_set_language (hb_buffer_t *buffer,
328 hb_language_t language);
329
330
331 HB_EXTERN hb_language_t
332 hb_buffer_get_language (const hb_buffer_t *buffer);
333
334 HB_EXTERN void
335 hb_buffer_set_segment_properties (hb_buffer_t *buffer,
336 const hb_segment_properties_t *props);
337
338 HB_EXTERN void
339 hb_buffer_get_segment_properties (const hb_buffer_t *buffer,
340 hb_segment_properties_t *props);
341
342 HB_EXTERN void
343 hb_buffer_guess_segment_properties (hb_buffer_t *buffer);
344
345
346 /**
347 * hb_buffer_flags_t:
348 * @HB_BUFFER_FLAG_DEFAULT: the default buffer flag.
349 * @HB_BUFFER_FLAG_BOT: flag indicating that special handling of the beginning
350 * of text paragraph can be applied to this buffer. Should usually
351 * be set, unless you are passing to the buffer only part
352 * of the text without the full context.
353 * @HB_BUFFER_FLAG_EOT: flag indicating that special handling of the end of text
354 * paragraph can be applied to this buffer, similar to
355 * @HB_BUFFER_FLAG_BOT.
356 * @HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES:
357 * flag indication that character with Default_Ignorable
358 * Unicode property should use the corresponding glyph
359 * from the font, instead of hiding them (done by
360 * replacing them with the space glyph and zeroing the
361 * advance width.) This flag takes precedence over
362 * @HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES.
363 * @HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES:
364 * flag indication that character with Default_Ignorable
365 * Unicode property should be removed from glyph string
366 * instead of hiding them (done by replacing them with the
367 * space glyph and zeroing the advance width.)
368 * @HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES takes
369 * precedence over this flag. Since: 1.8.0
370 * @HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE:
371 * flag indicating that a dotted circle should
372 * not be inserted in the rendering of incorrect
373 * character sequences (such at <0905 093E>). Since: 2.4.0
374 * @HB_BUFFER_FLAG_VERIFY:
375 * flag indicating that the hb_shape() call and its variants
376 * should perform various verification processes on the results
377 * of the shaping operation on the buffer. If the verification
378 * fails, then either a buffer message is sent, if a message
379 * handler is installed on the buffer, or a message is written
380 * to standard error. In either case, the shaping result might
381 * be modified to show the failed output. Since: 3.4.0
382 * @HB_BUFFER_FLAG_PRODUCE_UNSAFE_TO_CONCAT:
383 * flag indicating that the @HB_GLYPH_FLAG_UNSAFE_TO_CONCAT
384 * glyph-flag should be produced by the shaper. By default
385 * it will not be produced since it incurs a cost. Since: 4.0.0
386 * @HB_BUFFER_FLAG_PRODUCE_SAFE_TO_INSERT_TATWEEL:
387 * flag indicating that the @HB_GLYPH_FLAG_SAFE_TO_INSERT_TATWEEL
388 * glyph-flag should be produced by the shaper. By default
389 * it will not be produced. Since: 5.1.0
390 * @HB_BUFFER_FLAG_DEFINED: All currently defined flags: Since: 4.4.0
391 *
392 * Flags for #hb_buffer_t.
393 *
394 * Since: 0.9.20
395 */
396 typedef enum { /*< flags >*/
397 HB_BUFFER_FLAG_DEFAULT = 0x00000000u,
398 HB_BUFFER_FLAG_BOT = 0x00000001u, /* Beginning-of-text */
399 HB_BUFFER_FLAG_EOT = 0x00000002u, /* End-of-text */
400 HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES = 0x00000004u,
401 HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES = 0x00000008u,
402 HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE = 0x00000010u,
403 HB_BUFFER_FLAG_VERIFY = 0x00000020u,
404 HB_BUFFER_FLAG_PRODUCE_UNSAFE_TO_CONCAT = 0x00000040u,
405 HB_BUFFER_FLAG_PRODUCE_SAFE_TO_INSERT_TATWEEL = 0x00000080u,
406
407 HB_BUFFER_FLAG_DEFINED = 0x000000FFu
408 } hb_buffer_flags_t;
409
410 HB_EXTERN void
411 hb_buffer_set_flags (hb_buffer_t *buffer,
412 hb_buffer_flags_t flags);
413
414 HB_EXTERN hb_buffer_flags_t
415 hb_buffer_get_flags (const hb_buffer_t *buffer);
416
417 /**
418 * hb_buffer_cluster_level_t:
419 * @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES: Return cluster values grouped by graphemes into
420 * monotone order.
421 * @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS: Return cluster values grouped into monotone order.
422 * @HB_BUFFER_CLUSTER_LEVEL_CHARACTERS: Don't group cluster values.
423 * @HB_BUFFER_CLUSTER_LEVEL_DEFAULT: Default cluster level,
424 * equal to @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES.
425 *
426 * Data type for holding HarfBuzz's clustering behavior options. The cluster level
427 * dictates one aspect of how HarfBuzz will treat non-base characters
428 * during shaping.
429 *
430 * In @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES, non-base
431 * characters are merged into the cluster of the base character that precedes them.
432 *
433 * In @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS, non-base characters are initially
434 * assigned their own cluster values, which are not merged into preceding base
435 * clusters. This allows HarfBuzz to perform additional operations like reorder
436 * sequences of adjacent marks.
437 *
438 * @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES is the default, because it maintains
439 * backward compatibility with older versions of HarfBuzz. New client programs that
440 * do not need to maintain such backward compatibility are recommended to use
441 * @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS instead of the default.
442 *
443 * Since: 0.9.42
444 */
445 typedef enum {
446 HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES = 0,
447 HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS = 1,
448 HB_BUFFER_CLUSTER_LEVEL_CHARACTERS = 2,
449 HB_BUFFER_CLUSTER_LEVEL_DEFAULT = HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES
450 } hb_buffer_cluster_level_t;
451
452 HB_EXTERN void
453 hb_buffer_set_cluster_level (hb_buffer_t *buffer,
454 hb_buffer_cluster_level_t cluster_level);
455
456 HB_EXTERN hb_buffer_cluster_level_t
457 hb_buffer_get_cluster_level (const hb_buffer_t *buffer);
458
459 /**
460 * HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT:
461 *
462 * The default code point for replacing invalid characters in a given encoding.
463 * Set to U+FFFD REPLACEMENT CHARACTER.
464 *
465 * Since: 0.9.31
466 */
467 #define HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT 0xFFFDu
468
469 HB_EXTERN void
470 hb_buffer_set_replacement_codepoint (hb_buffer_t *buffer,
471 hb_codepoint_t replacement);
472
473 HB_EXTERN hb_codepoint_t
474 hb_buffer_get_replacement_codepoint (const hb_buffer_t *buffer);
475
476 HB_EXTERN void
477 hb_buffer_set_invisible_glyph (hb_buffer_t *buffer,
478 hb_codepoint_t invisible);
479
480 HB_EXTERN hb_codepoint_t
481 hb_buffer_get_invisible_glyph (const hb_buffer_t *buffer);
482
483 HB_EXTERN void
484 hb_buffer_set_not_found_glyph (hb_buffer_t *buffer,
485 hb_codepoint_t not_found);
486
487 HB_EXTERN hb_codepoint_t
488 hb_buffer_get_not_found_glyph (const hb_buffer_t *buffer);
489
490
491 /*
492 * Content API.
493 */
494
495 HB_EXTERN void
496 hb_buffer_clear_contents (hb_buffer_t *buffer);
497
498 HB_EXTERN hb_bool_t
499 hb_buffer_pre_allocate (hb_buffer_t *buffer,
500 unsigned int size);
501
502
503 HB_EXTERN hb_bool_t
504 hb_buffer_allocation_successful (hb_buffer_t *buffer);
505
506 HB_EXTERN void
507 hb_buffer_reverse (hb_buffer_t *buffer);
508
509 HB_EXTERN void
510 hb_buffer_reverse_range (hb_buffer_t *buffer,
511 unsigned int start, unsigned int end);
512
513 HB_EXTERN void
514 hb_buffer_reverse_clusters (hb_buffer_t *buffer);
515
516
517 /* Filling the buffer in */
518
519 HB_EXTERN void
520 hb_buffer_add (hb_buffer_t *buffer,
521 hb_codepoint_t codepoint,
522 unsigned int cluster);
523
524 HB_EXTERN void
525 hb_buffer_add_utf8 (hb_buffer_t *buffer,
526 const char *text,
527 int text_length,
528 unsigned int item_offset,
529 int item_length);
530
531 HB_EXTERN void
532 hb_buffer_add_utf16 (hb_buffer_t *buffer,
533 const uint16_t *text,
534 int text_length,
535 unsigned int item_offset,
536 int item_length);
537
538 HB_EXTERN void
539 hb_buffer_add_utf32 (hb_buffer_t *buffer,
540 const uint32_t *text,
541 int text_length,
542 unsigned int item_offset,
543 int item_length);
544
545 HB_EXTERN void
546 hb_buffer_add_latin1 (hb_buffer_t *buffer,
547 const uint8_t *text,
548 int text_length,
549 unsigned int item_offset,
550 int item_length);
551
552 HB_EXTERN void
553 hb_buffer_add_codepoints (hb_buffer_t *buffer,
554 const hb_codepoint_t *text,
555 int text_length,
556 unsigned int item_offset,
557 int item_length);
558
559 HB_EXTERN void
560 hb_buffer_append (hb_buffer_t *buffer,
561 const hb_buffer_t *source,
562 unsigned int start,
563 unsigned int end);
564
565 HB_EXTERN hb_bool_t
566 hb_buffer_set_length (hb_buffer_t *buffer,
567 unsigned int length);
568
569 HB_EXTERN unsigned int
570 hb_buffer_get_length (const hb_buffer_t *buffer);
571
572 /* Getting glyphs out of the buffer */
573
574 HB_EXTERN hb_glyph_info_t *
575 hb_buffer_get_glyph_infos (hb_buffer_t *buffer,
576 unsigned int *length);
577
578 HB_EXTERN hb_glyph_position_t *
579 hb_buffer_get_glyph_positions (hb_buffer_t *buffer,
580 unsigned int *length);
581
582 HB_EXTERN hb_bool_t
583 hb_buffer_has_positions (hb_buffer_t *buffer);
584
585
586 HB_EXTERN void
587 hb_buffer_normalize_glyphs (hb_buffer_t *buffer);
588
589
590 /*
591 * Serialize
592 */
593
594 /**
595 * hb_buffer_serialize_flags_t:
596 * @HB_BUFFER_SERIALIZE_FLAG_DEFAULT: serialize glyph names, clusters and positions.
597 * @HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS: do not serialize glyph cluster.
598 * @HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS: do not serialize glyph position information.
599 * @HB_BUFFER_SERIALIZE_FLAG_NO_GLYPH_NAMES: do no serialize glyph name.
600 * @HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS: serialize glyph extents.
601 * @HB_BUFFER_SERIALIZE_FLAG_GLYPH_FLAGS: serialize glyph flags. Since: 1.5.0
602 * @HB_BUFFER_SERIALIZE_FLAG_NO_ADVANCES: do not serialize glyph advances,
603 * glyph offsets will reflect absolute glyph positions. Since: 1.8.0
604 * @HB_BUFFER_SERIALIZE_FLAG_DEFINED: All currently defined flags. Since: 4.4.0
605 *
606 * Flags that control what glyph information are serialized in hb_buffer_serialize_glyphs().
607 *
608 * Since: 0.9.20
609 */
610 typedef enum { /*< flags >*/
611 HB_BUFFER_SERIALIZE_FLAG_DEFAULT = 0x00000000u,
612 HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS = 0x00000001u,
613 HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS = 0x00000002u,
614 HB_BUFFER_SERIALIZE_FLAG_NO_GLYPH_NAMES = 0x00000004u,
615 HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS = 0x00000008u,
616 HB_BUFFER_SERIALIZE_FLAG_GLYPH_FLAGS = 0x00000010u,
617 HB_BUFFER_SERIALIZE_FLAG_NO_ADVANCES = 0x00000020u,
618
619 HB_BUFFER_SERIALIZE_FLAG_DEFINED = 0x0000003Fu
620 } hb_buffer_serialize_flags_t;
621
622 /**
623 * hb_buffer_serialize_format_t:
624 * @HB_BUFFER_SERIALIZE_FORMAT_TEXT: a human-readable, plain text format.
625 * @HB_BUFFER_SERIALIZE_FORMAT_JSON: a machine-readable JSON format.
626 * @HB_BUFFER_SERIALIZE_FORMAT_INVALID: invalid format.
627 *
628 * The buffer serialization and de-serialization format used in
629 * hb_buffer_serialize_glyphs() and hb_buffer_deserialize_glyphs().
630 *
631 * Since: 0.9.2
632 */
633 typedef enum {
634 HB_BUFFER_SERIALIZE_FORMAT_TEXT = HB_TAG('T','E','X','T'),
635 HB_BUFFER_SERIALIZE_FORMAT_JSON = HB_TAG('J','S','O','N'),
636 HB_BUFFER_SERIALIZE_FORMAT_INVALID = HB_TAG_NONE
637 } hb_buffer_serialize_format_t;
638
639 HB_EXTERN hb_buffer_serialize_format_t
640 hb_buffer_serialize_format_from_string (const char *str, int len);
641
642 HB_EXTERN const char *
643 hb_buffer_serialize_format_to_string (hb_buffer_serialize_format_t format);
644
645 HB_EXTERN const char **
646 hb_buffer_serialize_list_formats (void);
647
648 HB_EXTERN unsigned int
649 hb_buffer_serialize_glyphs (hb_buffer_t *buffer,
650 unsigned int start,
651 unsigned int end,
652 char *buf,
653 unsigned int buf_size,
654 unsigned int *buf_consumed,
655 hb_font_t *font,
656 hb_buffer_serialize_format_t format,
657 hb_buffer_serialize_flags_t flags);
658
659 HB_EXTERN unsigned int
660 hb_buffer_serialize_unicode (hb_buffer_t *buffer,
661 unsigned int start,
662 unsigned int end,
663 char *buf,
664 unsigned int buf_size,
665 unsigned int *buf_consumed,
666 hb_buffer_serialize_format_t format,
667 hb_buffer_serialize_flags_t flags);
668
669 HB_EXTERN unsigned int
670 hb_buffer_serialize (hb_buffer_t *buffer,
671 unsigned int start,
672 unsigned int end,
673 char *buf,
674 unsigned int buf_size,
675 unsigned int *buf_consumed,
676 hb_font_t *font,
677 hb_buffer_serialize_format_t format,
678 hb_buffer_serialize_flags_t flags);
679
680 HB_EXTERN hb_bool_t
681 hb_buffer_deserialize_glyphs (hb_buffer_t *buffer,
682 const char *buf,
683 int buf_len,
684 const char **end_ptr,
685 hb_font_t *font,
686 hb_buffer_serialize_format_t format);
687
688 HB_EXTERN hb_bool_t
689 hb_buffer_deserialize_unicode (hb_buffer_t *buffer,
690 const char *buf,
691 int buf_len,
692 const char **end_ptr,
693 hb_buffer_serialize_format_t format);
694
695
696
697 /*
698 * Compare buffers
699 */
700
701 /**
702 * hb_buffer_diff_flags_t:
703 * @HB_BUFFER_DIFF_FLAG_EQUAL: equal buffers.
704 * @HB_BUFFER_DIFF_FLAG_CONTENT_TYPE_MISMATCH: buffers with different
705 * #hb_buffer_content_type_t.
706 * @HB_BUFFER_DIFF_FLAG_LENGTH_MISMATCH: buffers with differing length.
707 * @HB_BUFFER_DIFF_FLAG_NOTDEF_PRESENT: `.notdef` glyph is present in the
708 * reference buffer.
709 * @HB_BUFFER_DIFF_FLAG_DOTTED_CIRCLE_PRESENT: dotted circle glyph is present
710 * in the reference buffer.
711 * @HB_BUFFER_DIFF_FLAG_CODEPOINT_MISMATCH: difference in #hb_glyph_info_t.codepoint
712 * @HB_BUFFER_DIFF_FLAG_CLUSTER_MISMATCH: difference in #hb_glyph_info_t.cluster
713 * @HB_BUFFER_DIFF_FLAG_GLYPH_FLAGS_MISMATCH: difference in #hb_glyph_flags_t.
714 * @HB_BUFFER_DIFF_FLAG_POSITION_MISMATCH: difference in #hb_glyph_position_t.
715 *
716 * Flags from comparing two #hb_buffer_t's.
717 *
718 * Buffer with different #hb_buffer_content_type_t cannot be meaningfully
719 * compared in any further detail.
720 *
721 * For buffers with differing length, the per-glyph comparison is not
722 * attempted, though we do still scan reference buffer for dotted circle and
723 * `.notdef` glyphs.
724 *
725 * If the buffers have the same length, we compare them glyph-by-glyph and
726 * report which aspect(s) of the glyph info/position are different.
727 *
728 * Since: 1.5.0
729 */
730 typedef enum { /*< flags >*/
731 HB_BUFFER_DIFF_FLAG_EQUAL = 0x0000,
732
733 /* Buffers with different content_type cannot be meaningfully compared
734 * in any further detail. */
735 HB_BUFFER_DIFF_FLAG_CONTENT_TYPE_MISMATCH = 0x0001,
736
737 /* For buffers with differing length, the per-glyph comparison is not
738 * attempted, though we do still scan reference for dottedcircle / .notdef
739 * glyphs. */
740 HB_BUFFER_DIFF_FLAG_LENGTH_MISMATCH = 0x0002,
741
742 /* We want to know if dottedcircle / .notdef glyphs are present in the
743 * reference, as we may not care so much about other differences in this
744 * case. */
745 HB_BUFFER_DIFF_FLAG_NOTDEF_PRESENT = 0x0004,
746 HB_BUFFER_DIFF_FLAG_DOTTED_CIRCLE_PRESENT = 0x0008,
747
748 /* If the buffers have the same length, we compare them glyph-by-glyph
749 * and report which aspect(s) of the glyph info/position are different. */
750 HB_BUFFER_DIFF_FLAG_CODEPOINT_MISMATCH = 0x0010,
751 HB_BUFFER_DIFF_FLAG_CLUSTER_MISMATCH = 0x0020,
752 HB_BUFFER_DIFF_FLAG_GLYPH_FLAGS_MISMATCH = 0x0040,
753 HB_BUFFER_DIFF_FLAG_POSITION_MISMATCH = 0x0080
754
755 } hb_buffer_diff_flags_t;
756
757 /* Compare the contents of two buffers, report types of differences. */
758 HB_EXTERN hb_buffer_diff_flags_t
759 hb_buffer_diff (hb_buffer_t *buffer,
760 hb_buffer_t *reference,
761 hb_codepoint_t dottedcircle_glyph,
762 unsigned int position_fuzz);
763
764
765 /*
766 * Tracing.
767 */
768
769 /**
770 * hb_buffer_message_func_t:
771 * @buffer: An #hb_buffer_t to work upon
772 * @font: The #hb_font_t the @buffer is shaped with
773 * @message: `NULL`-terminated message passed to the function
774 * @user_data: User data pointer passed by the caller
775 *
776 * A callback method for #hb_buffer_t. The method gets called with the
777 * #hb_buffer_t it was set on, the #hb_font_t the buffer is shaped with and a
778 * message describing what step of the shaping process will be performed.
779 * Returning `false` from this method will skip this shaping step and move to
780 * the next one.
781 *
782 * Return value: `true` to perform the shaping step, `false` to skip it.
783 *
784 * Since: 1.1.3
785 */
786 typedef hb_bool_t (*hb_buffer_message_func_t) (hb_buffer_t *buffer,
787 hb_font_t *font,
788 const char *message,
789 void *user_data);
790
791 HB_EXTERN void
792 hb_buffer_set_message_func (hb_buffer_t *buffer,
793 hb_buffer_message_func_t func,
794 void *user_data, hb_destroy_func_t destroy);
795
796
797 HB_END_DECLS
798
799 #endif /* HB_BUFFER_H */