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;
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_position_t:
76  * @x_advance: how much the line advances after drawing this glyph when setting
77  *             text in horizontal direction.
78  * @y_advance: how much the line advances after drawing this glyph when setting
79  *             text in vertical direction.
80  * @x_offset: how much the glyph moves on the X-axis before drawing it, this
81  *            should not affect how much the line advances.
82  * @y_offset: how much the glyph moves on the Y-axis before drawing it, this
83  *            should not affect how much the line advances.
84  *
85  * The #hb_glyph_position_t is the structure that holds the positions of the
86  * glyph in both horizontal and vertical directions. All positions in
87  * #hb_glyph_position_t are relative to the current point.
88  *
89  */
90 typedef struct hb_glyph_position_t {
91   hb_position_t  x_advance;
92   hb_position_t  y_advance;
93   hb_position_t  x_offset;
94   hb_position_t  y_offset;
95 
96   /*< private >*/
97   hb_var_int_t   var;
98 } hb_glyph_position_t;
99 
100 /**
101  * hb_segment_properties_t:
102  * @direction: the #hb_direction_t of the buffer, see hb_buffer_set_direction().
103  * @script: the #hb_script_t of the buffer, see hb_buffer_set_script().
104  * @language: the #hb_language_t of the buffer, see hb_buffer_set_language().
105  *
106  * The structure that holds various text properties of an #hb_buffer_t. Can be
107  * set and retrieved using hb_buffer_set_segment_properties() and
108  * hb_buffer_get_segment_properties(), respectively.
109  */
110 typedef struct hb_segment_properties_t {
111   hb_direction_t  direction;
112   hb_script_t     script;
113   hb_language_t   language;
114   /*< private >*/
115   void           *reserved1;
116   void           *reserved2;
117 } hb_segment_properties_t;
118 
119 #define HB_SEGMENT_PROPERTIES_DEFAULT {HB_DIRECTION_INVALID, \
120 				       HB_SCRIPT_INVALID, \
121 				       HB_LANGUAGE_INVALID, \
122 				       NULL, \
123 				       NULL}
124 
125 HB_EXTERN hb_bool_t
126 hb_segment_properties_equal (const hb_segment_properties_t *a,
127 			     const hb_segment_properties_t *b);
128 
129 HB_EXTERN unsigned int
130 hb_segment_properties_hash (const hb_segment_properties_t *p);
131 
132 
133 
134 /**
135  * hb_buffer_t:
136  *
137  * The main structure holding the input text and its properties before shaping,
138  * and output glyphs and their information after shaping.
139  */
140 
141 typedef struct hb_buffer_t hb_buffer_t;
142 
143 HB_EXTERN hb_buffer_t *
144 hb_buffer_create (void);
145 
146 HB_EXTERN hb_buffer_t *
147 hb_buffer_get_empty (void);
148 
149 HB_EXTERN hb_buffer_t *
150 hb_buffer_reference (hb_buffer_t *buffer);
151 
152 HB_EXTERN void
153 hb_buffer_destroy (hb_buffer_t *buffer);
154 
155 HB_EXTERN hb_bool_t
156 hb_buffer_set_user_data (hb_buffer_t        *buffer,
157 			 hb_user_data_key_t *key,
158 			 void *              data,
159 			 hb_destroy_func_t   destroy,
160 			 hb_bool_t           replace);
161 
162 HB_EXTERN void *
163 hb_buffer_get_user_data (hb_buffer_t        *buffer,
164 			 hb_user_data_key_t *key);
165 
166 /**
167  * hb_buffer_content_type_t:
168  * @HB_BUFFER_CONTENT_TYPE_INVALID: Initial value for new buffer.
169  * @HB_BUFFER_CONTENT_TYPE_UNICODE: The buffer contains input characters (before shaping).
170  * @HB_BUFFER_CONTENT_TYPE_GLYPHS: The buffer contains output glyphs (after shaping).
171  */
172 typedef enum {
173   HB_BUFFER_CONTENT_TYPE_INVALID = 0,
174   HB_BUFFER_CONTENT_TYPE_UNICODE,
175   HB_BUFFER_CONTENT_TYPE_GLYPHS
176 } hb_buffer_content_type_t;
177 
178 HB_EXTERN void
179 hb_buffer_set_content_type (hb_buffer_t              *buffer,
180 			    hb_buffer_content_type_t  content_type);
181 
182 HB_EXTERN hb_buffer_content_type_t
183 hb_buffer_get_content_type (hb_buffer_t *buffer);
184 
185 
186 HB_EXTERN void
187 hb_buffer_set_unicode_funcs (hb_buffer_t        *buffer,
188 			     hb_unicode_funcs_t *unicode_funcs);
189 
190 HB_EXTERN hb_unicode_funcs_t *
191 hb_buffer_get_unicode_funcs (hb_buffer_t        *buffer);
192 
193 HB_EXTERN void
194 hb_buffer_set_direction (hb_buffer_t    *buffer,
195 			 hb_direction_t  direction);
196 
197 HB_EXTERN hb_direction_t
198 hb_buffer_get_direction (hb_buffer_t *buffer);
199 
200 HB_EXTERN void
201 hb_buffer_set_script (hb_buffer_t *buffer,
202 		      hb_script_t  script);
203 
204 HB_EXTERN hb_script_t
205 hb_buffer_get_script (hb_buffer_t *buffer);
206 
207 HB_EXTERN void
208 hb_buffer_set_language (hb_buffer_t   *buffer,
209 			hb_language_t  language);
210 
211 
212 HB_EXTERN hb_language_t
213 hb_buffer_get_language (hb_buffer_t *buffer);
214 
215 HB_EXTERN void
216 hb_buffer_set_segment_properties (hb_buffer_t *buffer,
217 				  const hb_segment_properties_t *props);
218 
219 HB_EXTERN void
220 hb_buffer_get_segment_properties (hb_buffer_t *buffer,
221 				  hb_segment_properties_t *props);
222 
223 HB_EXTERN void
224 hb_buffer_guess_segment_properties (hb_buffer_t *buffer);
225 
226 
227 /**
228  * hb_buffer_flags_t:
229  * @HB_BUFFER_FLAG_DEFAULT: the default buffer flag.
230  * @HB_BUFFER_FLAG_BOT: flag indicating that special handling of the beginning
231  *                      of text paragraph can be applied to this buffer. Should usually
232  *                      be set, unless you are passing to the buffer only part
233  *                      of the text without the full context.
234  * @HB_BUFFER_FLAG_EOT: flag indicating that special handling of the end of text
235  *                      paragraph can be applied to this buffer, similar to
236  *                      @HB_BUFFER_FLAG_EOT.
237  * @HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES:
238  *                      flag indication that character with Default_Ignorable
239  *                      Unicode property should use the corresponding glyph
240  *                      from the font, instead of hiding them (currently done
241  *                      by replacing them with the space glyph and zeroing the
242  *                      advance width.)
243  *
244  * Since: 0.9.20
245  */
246 typedef enum { /*< flags >*/
247   HB_BUFFER_FLAG_DEFAULT			= 0x00000000u,
248   HB_BUFFER_FLAG_BOT				= 0x00000001u, /* Beginning-of-text */
249   HB_BUFFER_FLAG_EOT				= 0x00000002u, /* End-of-text */
250   HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES	= 0x00000004u
251 } hb_buffer_flags_t;
252 
253 HB_EXTERN void
254 hb_buffer_set_flags (hb_buffer_t       *buffer,
255 		     hb_buffer_flags_t  flags);
256 
257 HB_EXTERN hb_buffer_flags_t
258 hb_buffer_get_flags (hb_buffer_t *buffer);
259 
260 /*
261  * Since: 0.9.42
262  */
263 typedef enum {
264   HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES	= 0,
265   HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS	= 1,
266   HB_BUFFER_CLUSTER_LEVEL_CHARACTERS		= 2,
267   HB_BUFFER_CLUSTER_LEVEL_DEFAULT = HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES
268 } hb_buffer_cluster_level_t;
269 
270 HB_EXTERN void
271 hb_buffer_set_cluster_level (hb_buffer_t               *buffer,
272 			     hb_buffer_cluster_level_t  cluster_level);
273 
274 HB_EXTERN hb_buffer_cluster_level_t
275 hb_buffer_get_cluster_level (hb_buffer_t *buffer);
276 
277 /**
278  * HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT:
279  *
280  * The default code point for replacing invalid characters in a given encoding.
281  * Set to U+FFFD REPLACEMENT CHARACTER.
282  *
283  * Since: 0.9.31
284  */
285 #define HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT 0xFFFDu
286 
287 HB_EXTERN void
288 hb_buffer_set_replacement_codepoint (hb_buffer_t    *buffer,
289 				     hb_codepoint_t  replacement);
290 
291 HB_EXTERN hb_codepoint_t
292 hb_buffer_get_replacement_codepoint (hb_buffer_t    *buffer);
293 
294 
295 HB_EXTERN void
296 hb_buffer_reset (hb_buffer_t *buffer);
297 
298 HB_EXTERN void
299 hb_buffer_clear_contents (hb_buffer_t *buffer);
300 
301 HB_EXTERN hb_bool_t
302 hb_buffer_pre_allocate (hb_buffer_t  *buffer,
303 		        unsigned int  size);
304 
305 
306 HB_EXTERN hb_bool_t
307 hb_buffer_allocation_successful (hb_buffer_t  *buffer);
308 
309 HB_EXTERN void
310 hb_buffer_reverse (hb_buffer_t *buffer);
311 
312 HB_EXTERN void
313 hb_buffer_reverse_range (hb_buffer_t *buffer,
314 			 unsigned int start, unsigned int end);
315 
316 HB_EXTERN void
317 hb_buffer_reverse_clusters (hb_buffer_t *buffer);
318 
319 
320 /* Filling the buffer in */
321 
322 HB_EXTERN void
323 hb_buffer_add (hb_buffer_t    *buffer,
324 	       hb_codepoint_t  codepoint,
325 	       unsigned int    cluster);
326 
327 HB_EXTERN void
328 hb_buffer_add_utf8 (hb_buffer_t  *buffer,
329 		    const char   *text,
330 		    int           text_length,
331 		    unsigned int  item_offset,
332 		    int           item_length);
333 
334 HB_EXTERN void
335 hb_buffer_add_utf16 (hb_buffer_t    *buffer,
336 		     const uint16_t *text,
337 		     int             text_length,
338 		     unsigned int    item_offset,
339 		     int             item_length);
340 
341 HB_EXTERN void
342 hb_buffer_add_utf32 (hb_buffer_t    *buffer,
343 		     const uint32_t *text,
344 		     int             text_length,
345 		     unsigned int    item_offset,
346 		     int             item_length);
347 
348 HB_EXTERN void
349 hb_buffer_add_latin1 (hb_buffer_t   *buffer,
350 		      const uint8_t *text,
351 		      int            text_length,
352 		      unsigned int   item_offset,
353 		      int            item_length);
354 
355 HB_EXTERN void
356 hb_buffer_add_codepoints (hb_buffer_t          *buffer,
357 			  const hb_codepoint_t *text,
358 			  int                   text_length,
359 			  unsigned int          item_offset,
360 			  int                   item_length);
361 
362 
363 HB_EXTERN hb_bool_t
364 hb_buffer_set_length (hb_buffer_t  *buffer,
365 		      unsigned int  length);
366 
367 HB_EXTERN unsigned int
368 hb_buffer_get_length (hb_buffer_t *buffer);
369 
370 /* Getting glyphs out of the buffer */
371 
372 HB_EXTERN hb_glyph_info_t *
373 hb_buffer_get_glyph_infos (hb_buffer_t  *buffer,
374                            unsigned int *length);
375 
376 HB_EXTERN hb_glyph_position_t *
377 hb_buffer_get_glyph_positions (hb_buffer_t  *buffer,
378                                unsigned int *length);
379 
380 
381 HB_EXTERN void
382 hb_buffer_normalize_glyphs (hb_buffer_t *buffer);
383 
384 
385 /*
386  * Serialize
387  */
388 
389 /**
390  * hb_buffer_serialize_flags_t:
391  * @HB_BUFFER_SERIALIZE_FLAG_DEFAULT: serialize glyph names, clusters and positions.
392  * @HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS: do not serialize glyph cluster.
393  * @HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS: do not serialize glyph position information.
394  * @HB_BUFFER_SERIALIZE_FLAG_NO_GLYPH_NAMES: do no serialize glyph name.
395  * @HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS: serialize glyph extents.
396  *
397  * Flags that control what glyph information are serialized in hb_buffer_serialize_glyphs().
398  *
399  * Since: 0.9.20
400  */
401 typedef enum { /*< flags >*/
402   HB_BUFFER_SERIALIZE_FLAG_DEFAULT		= 0x00000000u,
403   HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS		= 0x00000001u,
404   HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS		= 0x00000002u,
405   HB_BUFFER_SERIALIZE_FLAG_NO_GLYPH_NAMES	= 0x00000004u,
406   HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS	= 0x00000008u
407 } hb_buffer_serialize_flags_t;
408 
409 /**
410  * hb_buffer_serialize_format_t:
411  * @HB_BUFFER_SERIALIZE_FORMAT_TEXT: a human-readable, plain text format.
412  * @HB_BUFFER_SERIALIZE_FORMAT_JSON: a machine-readable JSON format.
413  * @HB_BUFFER_SERIALIZE_FORMAT_INVALID: invalid format.
414  *
415  * The buffer serialization and de-serialization format used in
416  * hb_buffer_serialize_glyphs() and hb_buffer_deserialize_glyphs().
417  *
418  * Since: 0.9.2
419  */
420 typedef enum {
421   HB_BUFFER_SERIALIZE_FORMAT_TEXT	= HB_TAG('T','E','X','T'),
422   HB_BUFFER_SERIALIZE_FORMAT_JSON	= HB_TAG('J','S','O','N'),
423   HB_BUFFER_SERIALIZE_FORMAT_INVALID	= HB_TAG_NONE
424 } hb_buffer_serialize_format_t;
425 
426 HB_EXTERN hb_buffer_serialize_format_t
427 hb_buffer_serialize_format_from_string (const char *str, int len);
428 
429 HB_EXTERN const char *
430 hb_buffer_serialize_format_to_string (hb_buffer_serialize_format_t format);
431 
432 HB_EXTERN const char **
433 hb_buffer_serialize_list_formats (void);
434 
435 HB_EXTERN unsigned int
436 hb_buffer_serialize_glyphs (hb_buffer_t *buffer,
437 			    unsigned int start,
438 			    unsigned int end,
439 			    char *buf,
440 			    unsigned int buf_size,
441 			    unsigned int *buf_consumed,
442 			    hb_font_t *font,
443 			    hb_buffer_serialize_format_t format,
444 			    hb_buffer_serialize_flags_t flags);
445 
446 HB_EXTERN hb_bool_t
447 hb_buffer_deserialize_glyphs (hb_buffer_t *buffer,
448 			      const char *buf,
449 			      int buf_len,
450 			      const char **end_ptr,
451 			      hb_font_t *font,
452 			      hb_buffer_serialize_format_t format);
453 
454 
455 /*
456  * Debugging.
457  */
458 
459 typedef hb_bool_t	(*hb_buffer_message_func_t)	(hb_buffer_t *buffer,
460 							 hb_font_t   *font,
461 							 const char  *message,
462 							 void        *user_data);
463 
464 HB_EXTERN void
465 hb_buffer_set_message_func (hb_buffer_t *buffer,
466 			    hb_buffer_message_func_t func,
467 			    void *user_data, hb_destroy_func_t destroy);
468 
469 
470 HB_END_DECLS
471 
472 #endif /* HB_BUFFER_H */
473