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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 #ifndef HB_H_IN
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  * @mask:
48  * @cluster: the index of the character in the original text that corresponds
49  *           to this #hb_glyph_info_t, or whatever the client passes to
50  *           hb_buffer_add(). More than one #hb_glyph_info_t can have the same
51  *           @cluster value, if they resulted from the same character (e.g. one
52  *           to many glyph substitution), and when more than one character gets
53  *           merged in the same glyph (e.g. many to one glyph substitution) the
54  *           #hb_glyph_info_t will have the smallest cluster value of them.
55  *           By default some characters are merged into the same cluster
56  *           (e.g. combining marks have the same cluster as their bases)
57  *           even if they are separate glyphs, hb_buffer_set_cluster_level()
58  *           allow selecting more fine-grained cluster handling.
59  *
60  * The #hb_glyph_info_t is the structure that holds information about the
61  * glyphs and their relation to input text.
62  *
63  */
64 typedef struct hb_glyph_info_t {
65   hb_codepoint_t codepoint;
66   hb_mask_t      mask; /* Holds hb_glyph_flags_t after hb_shape(), plus other things. */
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 typedef enum { /*< flags >*/
75   HB_GLYPH_FLAG_UNSAFE_TO_BREAK		= 0x00000001,
76 
77   HB_GLYPH_FLAG_DEFINED			= 0x00000001 /* OR of all defined flags */
78 } hb_glyph_flags_t;
79 
80 HB_EXTERN hb_glyph_flags_t
81 hb_glyph_info_get_glyph_flags (const hb_glyph_info_t *info);
82 
83 #define hb_glyph_info_get_glyph_flags(info) \
84 	((hb_glyph_flags_t) ((unsigned int) (info)->mask & HB_GLYPH_FLAG_DEFINED))
85 
86 
87 /**
88  * hb_glyph_position_t:
89  * @x_advance: how much the line advances after drawing this glyph when setting
90  *             text in horizontal direction.
91  * @y_advance: how much the line advances after drawing this glyph when setting
92  *             text in vertical direction.
93  * @x_offset: how much the glyph moves on the X-axis before drawing it, this
94  *            should not affect how much the line advances.
95  * @y_offset: how much the glyph moves on the Y-axis before drawing it, this
96  *            should not affect how much the line advances.
97  *
98  * The #hb_glyph_position_t is the structure that holds the positions of the
99  * glyph in both horizontal and vertical directions. All positions in
100  * #hb_glyph_position_t are relative to the current point.
101  *
102  */
103 typedef struct hb_glyph_position_t {
104   hb_position_t  x_advance;
105   hb_position_t  y_advance;
106   hb_position_t  x_offset;
107   hb_position_t  y_offset;
108 
109   /*< private >*/
110   hb_var_int_t   var;
111 } hb_glyph_position_t;
112 
113 /**
114  * hb_segment_properties_t:
115  * @direction: the #hb_direction_t of the buffer, see hb_buffer_set_direction().
116  * @script: the #hb_script_t of the buffer, see hb_buffer_set_script().
117  * @language: the #hb_language_t of the buffer, see hb_buffer_set_language().
118  *
119  * The structure that holds various text properties of an #hb_buffer_t. Can be
120  * set and retrieved using hb_buffer_set_segment_properties() and
121  * hb_buffer_get_segment_properties(), respectively.
122  */
123 typedef struct hb_segment_properties_t {
124   hb_direction_t  direction;
125   hb_script_t     script;
126   hb_language_t   language;
127   /*< private >*/
128   void           *reserved1;
129   void           *reserved2;
130 } hb_segment_properties_t;
131 
132 #define HB_SEGMENT_PROPERTIES_DEFAULT {HB_DIRECTION_INVALID, \
133 				       HB_SCRIPT_INVALID, \
134 				       HB_LANGUAGE_INVALID, \
135 				       (void *) 0, \
136 				       (void *) 0}
137 
138 HB_EXTERN hb_bool_t
139 hb_segment_properties_equal (const hb_segment_properties_t *a,
140 			     const hb_segment_properties_t *b);
141 
142 HB_EXTERN unsigned int
143 hb_segment_properties_hash (const hb_segment_properties_t *p);
144 
145 
146 
147 /**
148  * hb_buffer_t:
149  *
150  * The main structure holding the input text and its properties before shaping,
151  * and output glyphs and their information after shaping.
152  */
153 
154 typedef struct hb_buffer_t hb_buffer_t;
155 
156 HB_EXTERN hb_buffer_t *
157 hb_buffer_create (void);
158 
159 HB_EXTERN hb_buffer_t *
160 hb_buffer_get_empty (void);
161 
162 HB_EXTERN hb_buffer_t *
163 hb_buffer_reference (hb_buffer_t *buffer);
164 
165 HB_EXTERN void
166 hb_buffer_destroy (hb_buffer_t *buffer);
167 
168 HB_EXTERN hb_bool_t
169 hb_buffer_set_user_data (hb_buffer_t        *buffer,
170 			 hb_user_data_key_t *key,
171 			 void *              data,
172 			 hb_destroy_func_t   destroy,
173 			 hb_bool_t           replace);
174 
175 HB_EXTERN void *
176 hb_buffer_get_user_data (hb_buffer_t        *buffer,
177 			 hb_user_data_key_t *key);
178 
179 
180 /**
181  * hb_buffer_content_type_t:
182  * @HB_BUFFER_CONTENT_TYPE_INVALID: Initial value for new buffer.
183  * @HB_BUFFER_CONTENT_TYPE_UNICODE: The buffer contains input characters (before shaping).
184  * @HB_BUFFER_CONTENT_TYPE_GLYPHS: The buffer contains output glyphs (after shaping).
185  */
186 typedef enum {
187   HB_BUFFER_CONTENT_TYPE_INVALID = 0,
188   HB_BUFFER_CONTENT_TYPE_UNICODE,
189   HB_BUFFER_CONTENT_TYPE_GLYPHS
190 } hb_buffer_content_type_t;
191 
192 HB_EXTERN void
193 hb_buffer_set_content_type (hb_buffer_t              *buffer,
194 			    hb_buffer_content_type_t  content_type);
195 
196 HB_EXTERN hb_buffer_content_type_t
197 hb_buffer_get_content_type (hb_buffer_t *buffer);
198 
199 
200 HB_EXTERN void
201 hb_buffer_set_unicode_funcs (hb_buffer_t        *buffer,
202 			     hb_unicode_funcs_t *unicode_funcs);
203 
204 HB_EXTERN hb_unicode_funcs_t *
205 hb_buffer_get_unicode_funcs (hb_buffer_t        *buffer);
206 
207 HB_EXTERN void
208 hb_buffer_set_direction (hb_buffer_t    *buffer,
209 			 hb_direction_t  direction);
210 
211 HB_EXTERN hb_direction_t
212 hb_buffer_get_direction (hb_buffer_t *buffer);
213 
214 HB_EXTERN void
215 hb_buffer_set_script (hb_buffer_t *buffer,
216 		      hb_script_t  script);
217 
218 HB_EXTERN hb_script_t
219 hb_buffer_get_script (hb_buffer_t *buffer);
220 
221 HB_EXTERN void
222 hb_buffer_set_language (hb_buffer_t   *buffer,
223 			hb_language_t  language);
224 
225 
226 HB_EXTERN hb_language_t
227 hb_buffer_get_language (hb_buffer_t *buffer);
228 
229 HB_EXTERN void
230 hb_buffer_set_segment_properties (hb_buffer_t *buffer,
231 				  const hb_segment_properties_t *props);
232 
233 HB_EXTERN void
234 hb_buffer_get_segment_properties (hb_buffer_t *buffer,
235 				  hb_segment_properties_t *props);
236 
237 HB_EXTERN void
238 hb_buffer_guess_segment_properties (hb_buffer_t *buffer);
239 
240 
241 /**
242  * hb_buffer_flags_t:
243  * @HB_BUFFER_FLAG_DEFAULT: the default buffer flag.
244  * @HB_BUFFER_FLAG_BOT: flag indicating that special handling of the beginning
245  *                      of text paragraph can be applied to this buffer. Should usually
246  *                      be set, unless you are passing to the buffer only part
247  *                      of the text without the full context.
248  * @HB_BUFFER_FLAG_EOT: flag indicating that special handling of the end of text
249  *                      paragraph can be applied to this buffer, similar to
250  *                      @HB_BUFFER_FLAG_EOT.
251  * @HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES:
252  *                      flag indication that character with Default_Ignorable
253  *                      Unicode property should use the corresponding glyph
254  *                      from the font, instead of hiding them (currently done
255  *                      by replacing them with the space glyph and zeroing the
256  *                      advance width.)
257  *
258  * Since: 0.9.20
259  */
260 typedef enum { /*< flags >*/
261   HB_BUFFER_FLAG_DEFAULT			= 0x00000000u,
262   HB_BUFFER_FLAG_BOT				= 0x00000001u, /* Beginning-of-text */
263   HB_BUFFER_FLAG_EOT				= 0x00000002u, /* End-of-text */
264   HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES	= 0x00000004u
265 } hb_buffer_flags_t;
266 
267 HB_EXTERN void
268 hb_buffer_set_flags (hb_buffer_t       *buffer,
269 		     hb_buffer_flags_t  flags);
270 
271 HB_EXTERN hb_buffer_flags_t
272 hb_buffer_get_flags (hb_buffer_t *buffer);
273 
274 /*
275  * Since: 0.9.42
276  */
277 typedef enum {
278   HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES	= 0,
279   HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS	= 1,
280   HB_BUFFER_CLUSTER_LEVEL_CHARACTERS		= 2,
281   HB_BUFFER_CLUSTER_LEVEL_DEFAULT = HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES
282 } hb_buffer_cluster_level_t;
283 
284 HB_EXTERN void
285 hb_buffer_set_cluster_level (hb_buffer_t               *buffer,
286 			     hb_buffer_cluster_level_t  cluster_level);
287 
288 HB_EXTERN hb_buffer_cluster_level_t
289 hb_buffer_get_cluster_level (hb_buffer_t *buffer);
290 
291 /**
292  * HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT:
293  *
294  * The default code point for replacing invalid characters in a given encoding.
295  * Set to U+FFFD REPLACEMENT CHARACTER.
296  *
297  * Since: 0.9.31
298  */
299 #define HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT 0xFFFDu
300 
301 HB_EXTERN void
302 hb_buffer_set_replacement_codepoint (hb_buffer_t    *buffer,
303 				     hb_codepoint_t  replacement);
304 
305 HB_EXTERN hb_codepoint_t
306 hb_buffer_get_replacement_codepoint (hb_buffer_t    *buffer);
307 
308 
309 HB_EXTERN void
310 hb_buffer_reset (hb_buffer_t *buffer);
311 
312 HB_EXTERN void
313 hb_buffer_clear_contents (hb_buffer_t *buffer);
314 
315 HB_EXTERN hb_bool_t
316 hb_buffer_pre_allocate (hb_buffer_t  *buffer,
317 		        unsigned int  size);
318 
319 
320 HB_EXTERN hb_bool_t
321 hb_buffer_allocation_successful (hb_buffer_t  *buffer);
322 
323 HB_EXTERN void
324 hb_buffer_reverse (hb_buffer_t *buffer);
325 
326 HB_EXTERN void
327 hb_buffer_reverse_range (hb_buffer_t *buffer,
328 			 unsigned int start, unsigned int end);
329 
330 HB_EXTERN void
331 hb_buffer_reverse_clusters (hb_buffer_t *buffer);
332 
333 
334 /* Filling the buffer in */
335 
336 HB_EXTERN void
337 hb_buffer_add (hb_buffer_t    *buffer,
338 	       hb_codepoint_t  codepoint,
339 	       unsigned int    cluster);
340 
341 HB_EXTERN void
342 hb_buffer_add_utf8 (hb_buffer_t  *buffer,
343 		    const char   *text,
344 		    int           text_length,
345 		    unsigned int  item_offset,
346 		    int           item_length);
347 
348 HB_EXTERN void
349 hb_buffer_add_utf16 (hb_buffer_t    *buffer,
350 		     const uint16_t *text,
351 		     int             text_length,
352 		     unsigned int    item_offset,
353 		     int             item_length);
354 
355 HB_EXTERN void
356 hb_buffer_add_utf32 (hb_buffer_t    *buffer,
357 		     const uint32_t *text,
358 		     int             text_length,
359 		     unsigned int    item_offset,
360 		     int             item_length);
361 
362 HB_EXTERN void
363 hb_buffer_add_latin1 (hb_buffer_t   *buffer,
364 		      const uint8_t *text,
365 		      int            text_length,
366 		      unsigned int   item_offset,
367 		      int            item_length);
368 
369 HB_EXTERN void
370 hb_buffer_add_codepoints (hb_buffer_t          *buffer,
371 			  const hb_codepoint_t *text,
372 			  int                   text_length,
373 			  unsigned int          item_offset,
374 			  int                   item_length);
375 
376 HB_EXTERN void
377 hb_buffer_append (hb_buffer_t *buffer,
378 		  hb_buffer_t *source,
379 		  unsigned int start,
380 		  unsigned int end);
381 
382 HB_EXTERN hb_bool_t
383 hb_buffer_set_length (hb_buffer_t  *buffer,
384 		      unsigned int  length);
385 
386 HB_EXTERN unsigned int
387 hb_buffer_get_length (hb_buffer_t *buffer);
388 
389 /* Getting glyphs out of the buffer */
390 
391 HB_EXTERN hb_glyph_info_t *
392 hb_buffer_get_glyph_infos (hb_buffer_t  *buffer,
393                            unsigned int *length);
394 
395 HB_EXTERN hb_glyph_position_t *
396 hb_buffer_get_glyph_positions (hb_buffer_t  *buffer,
397                                unsigned int *length);
398 
399 
400 HB_EXTERN void
401 hb_buffer_normalize_glyphs (hb_buffer_t *buffer);
402 
403 
404 /*
405  * Serialize
406  */
407 
408 /**
409  * hb_buffer_serialize_flags_t:
410  * @HB_BUFFER_SERIALIZE_FLAG_DEFAULT: serialize glyph names, clusters and positions.
411  * @HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS: do not serialize glyph cluster.
412  * @HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS: do not serialize glyph position information.
413  * @HB_BUFFER_SERIALIZE_FLAG_NO_GLYPH_NAMES: do no serialize glyph name.
414  * @HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS: serialize glyph extents.
415  *
416  * Flags that control what glyph information are serialized in hb_buffer_serialize_glyphs().
417  *
418  * Since: 0.9.20
419  */
420 typedef enum { /*< flags >*/
421   HB_BUFFER_SERIALIZE_FLAG_DEFAULT		= 0x00000000u,
422   HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS		= 0x00000001u,
423   HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS		= 0x00000002u,
424   HB_BUFFER_SERIALIZE_FLAG_NO_GLYPH_NAMES	= 0x00000004u,
425   HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS	= 0x00000008u,
426   HB_BUFFER_SERIALIZE_FLAG_GLYPH_FLAGS		= 0x00000010u
427 } hb_buffer_serialize_flags_t;
428 
429 /**
430  * hb_buffer_serialize_format_t:
431  * @HB_BUFFER_SERIALIZE_FORMAT_TEXT: a human-readable, plain text format.
432  * @HB_BUFFER_SERIALIZE_FORMAT_JSON: a machine-readable JSON format.
433  * @HB_BUFFER_SERIALIZE_FORMAT_INVALID: invalid format.
434  *
435  * The buffer serialization and de-serialization format used in
436  * hb_buffer_serialize_glyphs() and hb_buffer_deserialize_glyphs().
437  *
438  * Since: 0.9.2
439  */
440 typedef enum {
441   HB_BUFFER_SERIALIZE_FORMAT_TEXT	= HB_TAG('T','E','X','T'),
442   HB_BUFFER_SERIALIZE_FORMAT_JSON	= HB_TAG('J','S','O','N'),
443   HB_BUFFER_SERIALIZE_FORMAT_INVALID	= HB_TAG_NONE
444 } hb_buffer_serialize_format_t;
445 
446 HB_EXTERN hb_buffer_serialize_format_t
447 hb_buffer_serialize_format_from_string (const char *str, int len);
448 
449 HB_EXTERN const char *
450 hb_buffer_serialize_format_to_string (hb_buffer_serialize_format_t format);
451 
452 HB_EXTERN const char **
453 hb_buffer_serialize_list_formats (void);
454 
455 HB_EXTERN unsigned int
456 hb_buffer_serialize_glyphs (hb_buffer_t *buffer,
457 			    unsigned int start,
458 			    unsigned int end,
459 			    char *buf,
460 			    unsigned int buf_size,
461 			    unsigned int *buf_consumed,
462 			    hb_font_t *font,
463 			    hb_buffer_serialize_format_t format,
464 			    hb_buffer_serialize_flags_t flags);
465 
466 HB_EXTERN hb_bool_t
467 hb_buffer_deserialize_glyphs (hb_buffer_t *buffer,
468 			      const char *buf,
469 			      int buf_len,
470 			      const char **end_ptr,
471 			      hb_font_t *font,
472 			      hb_buffer_serialize_format_t format);
473 
474 
475 /*
476  * Compare buffers
477  */
478 
479 typedef enum { /*< flags >*/
480   HB_BUFFER_DIFF_FLAG_EQUAL			= 0x0000,
481 
482   /* Buffers with different content_type cannot be meaningfully compared
483    * in any further detail. */
484   HB_BUFFER_DIFF_FLAG_CONTENT_TYPE_MISMATCH	= 0x0001,
485 
486   /* For buffers with differing length, the per-glyph comparison is not
487    * attempted, though we do still scan reference for dottedcircle / .notdef
488    * glyphs. */
489   HB_BUFFER_DIFF_FLAG_LENGTH_MISMATCH		= 0x0002,
490 
491   /* We want to know if dottedcircle / .notdef glyphs are present in the
492    * reference, as we may not care so much about other differences in this
493    * case. */
494   HB_BUFFER_DIFF_FLAG_NOTDEF_PRESENT		= 0x0004,
495   HB_BUFFER_DIFF_FLAG_DOTTED_CIRCLE_PRESENT	= 0x0008,
496 
497   /* If the buffers have the same length, we compare them glyph-by-glyph
498    * and report which aspect(s) of the glyph info/position are different. */
499   HB_BUFFER_DIFF_FLAG_CODEPOINT_MISMATCH	= 0x0010,
500   HB_BUFFER_DIFF_FLAG_CLUSTER_MISMATCH		= 0x0020,
501   HB_BUFFER_DIFF_FLAG_GLYPH_FLAGS_MISMATCH	= 0x0040,
502   HB_BUFFER_DIFF_FLAG_POSITION_MISMATCH		= 0x0080
503 
504 } hb_buffer_diff_flags_t;
505 
506 /* Compare the contents of two buffers, report types of differences. */
507 HB_EXTERN hb_buffer_diff_flags_t
508 hb_buffer_diff (hb_buffer_t *buffer,
509 		hb_buffer_t *reference,
510 		hb_codepoint_t dottedcircle_glyph,
511 		unsigned int position_fuzz);
512 
513 
514 /*
515  * Debugging.
516  */
517 
518 typedef hb_bool_t	(*hb_buffer_message_func_t)	(hb_buffer_t *buffer,
519 							 hb_font_t   *font,
520 							 const char  *message,
521 							 void        *user_data);
522 
523 HB_EXTERN void
524 hb_buffer_set_message_func (hb_buffer_t *buffer,
525 			    hb_buffer_message_func_t func,
526 			    void *user_data, hb_destroy_func_t destroy);
527 
528 
529 HB_END_DECLS
530 
531 #endif /* HB_BUFFER_H */
532