1 /*
2  * Copyright © 2007,2008,2009  Red Hat, Inc.
3  *
4  *  This is part of HarfBuzz, a text shaping library.
5  *
6  * Permission is hereby granted, without written agreement and without
7  * license or royalty fees, to use, copy, modify, and distribute this
8  * software and its documentation for any purpose, provided that the
9  * above copyright notice and the following two paragraphs appear in
10  * all copies of this software.
11  *
12  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16  * DAMAGE.
17  *
18  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
21  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23  *
24  * Red Hat Author(s): Behdad Esfahbod
25  */
26 
27 #ifndef HB_OT_H_IN
28 #error "Include <hb-ot.h> instead."
29 #endif
30 
31 #ifndef HB_OT_LAYOUT_H
32 #define HB_OT_LAYOUT_H
33 
34 #include "hb.h"
35 
36 #include "hb-ot-name.h"
37 
38 HB_BEGIN_DECLS
39 
40 
41 #define HB_OT_TAG_BASE HB_TAG('B','A','S','E')
42 #define HB_OT_TAG_GDEF HB_TAG('G','D','E','F')
43 #define HB_OT_TAG_GSUB HB_TAG('G','S','U','B')
44 #define HB_OT_TAG_GPOS HB_TAG('G','P','O','S')
45 #define HB_OT_TAG_JSTF HB_TAG('J','S','T','F')
46 
47 
48 /*
49  * Script & Language tags.
50  */
51 
52 #define HB_OT_TAG_DEFAULT_SCRIPT	HB_TAG ('D', 'F', 'L', 'T')
53 #define HB_OT_TAG_DEFAULT_LANGUAGE	HB_TAG ('d', 'f', 'l', 't')
54 
55 /**
56  * HB_OT_MAX_TAGS_PER_SCRIPT:
57  *
58  * Since: 2.0.0
59  **/
60 #define HB_OT_MAX_TAGS_PER_SCRIPT	3u
61 /**
62  * HB_OT_MAX_TAGS_PER_LANGUAGE:
63  *
64  * Since: 2.0.0
65  **/
66 #define HB_OT_MAX_TAGS_PER_LANGUAGE	3u
67 
68 HB_EXTERN void
69 hb_ot_tags_from_script_and_language (hb_script_t   script,
70 				     hb_language_t language,
71 				     unsigned int *script_count /* IN/OUT */,
72 				     hb_tag_t     *script_tags /* OUT */,
73 				     unsigned int *language_count /* IN/OUT */,
74 				     hb_tag_t     *language_tags /* OUT */);
75 
76 HB_EXTERN hb_script_t
77 hb_ot_tag_to_script (hb_tag_t tag);
78 
79 HB_EXTERN hb_language_t
80 hb_ot_tag_to_language (hb_tag_t tag);
81 
82 HB_EXTERN void
83 hb_ot_tags_to_script_and_language (hb_tag_t       script_tag,
84 				   hb_tag_t       language_tag,
85 				   hb_script_t   *script /* OUT */,
86 				   hb_language_t *language /* OUT */);
87 
88 
89 /*
90  * GDEF
91  */
92 
93 HB_EXTERN hb_bool_t
94 hb_ot_layout_has_glyph_classes (hb_face_t *face);
95 
96 /**
97  * hb_ot_layout_glyph_class_t:
98  * @HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED: Glyphs not matching the other classifications
99  * @HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH: Spacing, single characters, capable of accepting marks
100  * @HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE: Glyphs that represent ligation of multiple characters
101  * @HB_OT_LAYOUT_GLYPH_CLASS_MARK: Non-spacing, combining glyphs that represent marks
102  * @HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT: Spacing glyphs that represent part of a single character
103  *
104  * The GDEF classes defined for glyphs.
105  *
106  **/
107 typedef enum {
108   HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED	= 0,
109   HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH	= 1,
110   HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE	= 2,
111   HB_OT_LAYOUT_GLYPH_CLASS_MARK		= 3,
112   HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT	= 4
113 } hb_ot_layout_glyph_class_t;
114 
115 HB_EXTERN hb_ot_layout_glyph_class_t
116 hb_ot_layout_get_glyph_class (hb_face_t      *face,
117 			      hb_codepoint_t  glyph);
118 
119 HB_EXTERN void
120 hb_ot_layout_get_glyphs_in_class (hb_face_t                  *face,
121 				  hb_ot_layout_glyph_class_t  klass,
122 				  hb_set_t                   *glyphs /* OUT */);
123 
124 
125 /* Not that useful.  Provides list of attach points for a glyph that a
126  * client may want to cache */
127 HB_EXTERN unsigned int
128 hb_ot_layout_get_attach_points (hb_face_t      *face,
129 				hb_codepoint_t  glyph,
130 				unsigned int    start_offset,
131 				unsigned int   *point_count /* IN/OUT */,
132 				unsigned int   *point_array /* OUT */);
133 
134 /* Ligature caret positions */
135 HB_EXTERN unsigned int
136 hb_ot_layout_get_ligature_carets (hb_font_t      *font,
137 				  hb_direction_t  direction,
138 				  hb_codepoint_t  glyph,
139 				  unsigned int    start_offset,
140 				  unsigned int   *caret_count /* IN/OUT */,
141 				  hb_position_t  *caret_array /* OUT */);
142 
143 
144 /*
145  * GSUB/GPOS feature query and enumeration interface
146  */
147 
148 #define HB_OT_LAYOUT_NO_SCRIPT_INDEX		0xFFFFu
149 #define HB_OT_LAYOUT_NO_FEATURE_INDEX		0xFFFFu
150 #define HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX	0xFFFFu
151 #define HB_OT_LAYOUT_NO_VARIATIONS_INDEX	0xFFFFFFFFu
152 
153 HB_EXTERN unsigned int
154 hb_ot_layout_table_get_script_tags (hb_face_t    *face,
155 				    hb_tag_t      table_tag,
156 				    unsigned int  start_offset,
157 				    unsigned int *script_count /* IN/OUT */,
158 				    hb_tag_t     *script_tags /* OUT */);
159 
160 HB_EXTERN hb_bool_t
161 hb_ot_layout_table_find_script (hb_face_t    *face,
162 				hb_tag_t      table_tag,
163 				hb_tag_t      script_tag,
164 				unsigned int *script_index);
165 
166 HB_EXTERN hb_bool_t
167 hb_ot_layout_table_select_script (hb_face_t      *face,
168 				  hb_tag_t        table_tag,
169 				  unsigned int    script_count,
170 				  const hb_tag_t *script_tags,
171 				  unsigned int   *script_index /* OUT */,
172 				  hb_tag_t       *chosen_script /* OUT */);
173 
174 HB_EXTERN unsigned int
175 hb_ot_layout_table_get_feature_tags (hb_face_t    *face,
176 				     hb_tag_t      table_tag,
177 				     unsigned int  start_offset,
178 				     unsigned int *feature_count /* IN/OUT */,
179 				     hb_tag_t     *feature_tags /* OUT */);
180 
181 HB_EXTERN unsigned int
182 hb_ot_layout_script_get_language_tags (hb_face_t    *face,
183 				       hb_tag_t      table_tag,
184 				       unsigned int  script_index,
185 				       unsigned int  start_offset,
186 				       unsigned int *language_count /* IN/OUT */,
187 				       hb_tag_t     *language_tags /* OUT */);
188 
189 HB_EXTERN hb_bool_t
190 hb_ot_layout_script_select_language (hb_face_t      *face,
191 				     hb_tag_t        table_tag,
192 				     unsigned int    script_index,
193 				     unsigned int    language_count,
194 				     const hb_tag_t *language_tags,
195 				     unsigned int   *language_index /* OUT */);
196 
197 HB_EXTERN hb_bool_t
198 hb_ot_layout_language_get_required_feature_index (hb_face_t    *face,
199 						  hb_tag_t      table_tag,
200 						  unsigned int  script_index,
201 						  unsigned int  language_index,
202 						  unsigned int *feature_index);
203 
204 HB_EXTERN hb_bool_t
205 hb_ot_layout_language_get_required_feature (hb_face_t    *face,
206 					    hb_tag_t      table_tag,
207 					    unsigned int  script_index,
208 					    unsigned int  language_index,
209 					    unsigned int *feature_index,
210 					    hb_tag_t     *feature_tag);
211 
212 HB_EXTERN unsigned int
213 hb_ot_layout_language_get_feature_indexes (hb_face_t    *face,
214 					   hb_tag_t      table_tag,
215 					   unsigned int  script_index,
216 					   unsigned int  language_index,
217 					   unsigned int  start_offset,
218 					   unsigned int *feature_count /* IN/OUT */,
219 					   unsigned int *feature_indexes /* OUT */);
220 
221 HB_EXTERN unsigned int
222 hb_ot_layout_language_get_feature_tags (hb_face_t    *face,
223 					hb_tag_t      table_tag,
224 					unsigned int  script_index,
225 					unsigned int  language_index,
226 					unsigned int  start_offset,
227 					unsigned int *feature_count /* IN/OUT */,
228 					hb_tag_t     *feature_tags /* OUT */);
229 
230 HB_EXTERN hb_bool_t
231 hb_ot_layout_language_find_feature (hb_face_t    *face,
232 				    hb_tag_t      table_tag,
233 				    unsigned int  script_index,
234 				    unsigned int  language_index,
235 				    hb_tag_t      feature_tag,
236 				    unsigned int *feature_index);
237 
238 HB_EXTERN unsigned int
239 hb_ot_layout_feature_get_lookups (hb_face_t    *face,
240 				  hb_tag_t      table_tag,
241 				  unsigned int  feature_index,
242 				  unsigned int  start_offset,
243 				  unsigned int *lookup_count /* IN/OUT */,
244 				  unsigned int *lookup_indexes /* OUT */);
245 
246 HB_EXTERN unsigned int
247 hb_ot_layout_table_get_lookup_count (hb_face_t    *face,
248 				     hb_tag_t      table_tag);
249 
250 HB_EXTERN void
251 hb_ot_layout_collect_features (hb_face_t      *face,
252 			       hb_tag_t        table_tag,
253 			       const hb_tag_t *scripts,
254 			       const hb_tag_t *languages,
255 			       const hb_tag_t *features,
256 			       hb_set_t       *feature_indexes /* OUT */);
257 
258 HB_EXTERN void
259 hb_ot_layout_collect_lookups (hb_face_t      *face,
260 			      hb_tag_t        table_tag,
261 			      const hb_tag_t *scripts,
262 			      const hb_tag_t *languages,
263 			      const hb_tag_t *features,
264 			      hb_set_t       *lookup_indexes /* OUT */);
265 
266 HB_EXTERN void
267 hb_ot_layout_lookup_collect_glyphs (hb_face_t    *face,
268 				    hb_tag_t      table_tag,
269 				    unsigned int  lookup_index,
270 				    hb_set_t     *glyphs_before, /* OUT.  May be NULL */
271 				    hb_set_t     *glyphs_input,  /* OUT.  May be NULL */
272 				    hb_set_t     *glyphs_after,  /* OUT.  May be NULL */
273 				    hb_set_t     *glyphs_output  /* OUT.  May be NULL */);
274 
275 #ifdef HB_NOT_IMPLEMENTED
276 typedef struct
277 {
278   const hb_codepoint_t *before,
279   unsigned int          before_length,
280   const hb_codepoint_t *input,
281   unsigned int          input_length,
282   const hb_codepoint_t *after,
283   unsigned int          after_length,
284 } hb_ot_layout_glyph_sequence_t;
285 
286 typedef hb_bool_t
287 (*hb_ot_layout_glyph_sequence_func_t) (hb_font_t    *font,
288 				       hb_tag_t      table_tag,
289 				       unsigned int  lookup_index,
290 				       const hb_ot_layout_glyph_sequence_t *sequence,
291 				       void         *user_data);
292 
293 HB_EXTERN void
294 Xhb_ot_layout_lookup_enumerate_sequences (hb_face_t    *face,
295 					 hb_tag_t      table_tag,
296 					 unsigned int  lookup_index,
297 					 hb_ot_layout_glyph_sequence_func_t callback,
298 					 void         *user_data);
299 #endif
300 
301 /* Variations support */
302 
303 HB_EXTERN hb_bool_t
304 hb_ot_layout_table_find_feature_variations (hb_face_t    *face,
305 					    hb_tag_t      table_tag,
306 					    const int    *coords,
307 					    unsigned int  num_coords,
308 					    unsigned int *variations_index /* out */);
309 
310 HB_EXTERN unsigned int
311 hb_ot_layout_feature_with_variations_get_lookups (hb_face_t    *face,
312 						  hb_tag_t      table_tag,
313 						  unsigned int  feature_index,
314 						  unsigned int  variations_index,
315 						  unsigned int  start_offset,
316 						  unsigned int *lookup_count /* IN/OUT */,
317 						  unsigned int *lookup_indexes /* OUT */);
318 
319 
320 /*
321  * GSUB
322  */
323 
324 HB_EXTERN hb_bool_t
325 hb_ot_layout_has_substitution (hb_face_t *face);
326 
327 HB_EXTERN hb_bool_t
328 hb_ot_layout_lookup_would_substitute (hb_face_t            *face,
329 				      unsigned int          lookup_index,
330 				      const hb_codepoint_t *glyphs,
331 				      unsigned int          glyphs_length,
332 				      hb_bool_t             zero_context);
333 
334 HB_EXTERN void
335 hb_ot_layout_lookup_substitute_closure (hb_face_t    *face,
336 					unsigned int  lookup_index,
337 					hb_set_t     *glyphs
338 					/*TODO , hb_bool_t  inclusive */);
339 
340 HB_EXTERN void
341 hb_ot_layout_lookups_substitute_closure (hb_face_t      *face,
342 					 const hb_set_t *lookups,
343 					 hb_set_t       *glyphs);
344 
345 
346 #ifdef HB_NOT_IMPLEMENTED
347 /* Note: You better have GDEF when using this API, or marks won't do much. */
348 HB_EXTERN hb_bool_t
349 Xhb_ot_layout_lookup_substitute (hb_font_t            *font,
350 				unsigned int          lookup_index,
351 				const hb_ot_layout_glyph_sequence_t *sequence,
352 				unsigned int          out_size,
353 				hb_codepoint_t       *glyphs_out,   /* OUT */
354 				unsigned int         *clusters_out, /* OUT */
355 				unsigned int         *out_length    /* OUT */);
356 #endif
357 
358 
359 /*
360  * GPOS
361  */
362 
363 HB_EXTERN hb_bool_t
364 hb_ot_layout_has_positioning (hb_face_t *face);
365 
366 #ifdef HB_NOT_IMPLEMENTED
367 /* Note: You better have GDEF when using this API, or marks won't do much. */
368 HB_EXTERN hb_bool_t
369 Xhb_ot_layout_lookup_position (hb_font_t            *font,
370 			      unsigned int          lookup_index,
371 			      const hb_ot_layout_glyph_sequence_t *sequence,
372 			      hb_glyph_position_t  *positions /* IN / OUT */);
373 #endif
374 
375 /* Optical 'size' feature info.  Returns true if found.
376  * https://docs.microsoft.com/en-us/typography/opentype/spec/features_pt#size */
377 HB_EXTERN hb_bool_t
378 hb_ot_layout_get_size_params (hb_face_t       *face,
379 			      unsigned int    *design_size,       /* OUT.  May be NULL */
380 			      unsigned int    *subfamily_id,      /* OUT.  May be NULL */
381 			      hb_ot_name_id_t *subfamily_name_id, /* OUT.  May be NULL */
382 			      unsigned int    *range_start,       /* OUT.  May be NULL */
383 			      unsigned int    *range_end          /* OUT.  May be NULL */);
384 
385 
386 HB_EXTERN hb_bool_t
387 hb_ot_layout_feature_get_name_ids (hb_face_t       *face,
388 				   hb_tag_t         table_tag,
389 				   unsigned int     feature_index,
390 				   hb_ot_name_id_t *label_id             /* OUT.  May be NULL */,
391 				   hb_ot_name_id_t *tooltip_id           /* OUT.  May be NULL */,
392 				   hb_ot_name_id_t *sample_id            /* OUT.  May be NULL */,
393 				   unsigned int    *num_named_parameters /* OUT.  May be NULL */,
394 				   hb_ot_name_id_t *first_param_id       /* OUT.  May be NULL */);
395 
396 
397 HB_EXTERN unsigned int
398 hb_ot_layout_feature_get_characters (hb_face_t      *face,
399 				     hb_tag_t        table_tag,
400 				     unsigned int    feature_index,
401 				     unsigned int    start_offset,
402 				     unsigned int   *char_count    /* IN/OUT.  May be NULL */,
403 				     hb_codepoint_t *characters    /* OUT.     May be NULL */);
404 
405 /*
406  * BASE
407  */
408 
409 /**
410  * hb_ot_layout_baseline_tag_t:
411  * @HB_OT_LAYOUT_BASELINE_TAG_ROMAN: The baseline used by alphabetic scripts such as Latin, Cyrillic and Greek.
412  * In vertical writing mode, the alphabetic baseline for characters rotated 90 degrees clockwise.
413  * (This would not apply to alphabetic characters that remain upright in vertical writing mode, since these
414  * characters are not rotated.)
415  * @HB_OT_LAYOUT_BASELINE_TAG_HANGING: The hanging baseline. In horizontal direction, this is the horizontal
416  * line from which syllables seem, to hang in Tibetan and other similar scripts. In vertical writing mode,
417  * for Tibetan (or some other similar script) characters rotated 90 degrees clockwise.
418  * @HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_BOTTOM_OR_LEFT: Ideographic character face bottom or left edge,
419  * if the direction is horizontal or vertical, respectively.
420  * @HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_TOP_OR_RIGHT: Ideographic character face top or right edge,
421  * if the direction is horizontal or vertical, respectively.
422  * @HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_BOTTOM_OR_LEFT: Ideographic em-box bottom or left edge,
423  * if the direction is horizontal or vertical, respectively.
424  * @HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_TOP_OR_RIGHT: Ideographic em-box top or right edge baseline,
425  * if the direction is horizontal or vertical, respectively.
426  * @HB_OT_LAYOUT_BASELINE_TAG_MATH: The baseline about which mathematical characters are centered.
427  * In vertical writing mode when mathematical characters rotated 90 degrees clockwise, are centered.
428  *
429  * Baseline tags from https://docs.microsoft.com/en-us/typography/opentype/spec/baselinetags
430  *
431  * Since: 2.6.0
432  */
433 typedef enum {
434   HB_OT_LAYOUT_BASELINE_TAG_ROMAN			= HB_TAG ('r','o','m','n'),
435   HB_OT_LAYOUT_BASELINE_TAG_HANGING			= HB_TAG ('h','a','n','g'),
436   HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_BOTTOM_OR_LEFT	= HB_TAG ('i','c','f','b'),
437   HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_TOP_OR_RIGHT	= HB_TAG ('i','c','f','t'),
438   HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_BOTTOM_OR_LEFT	= HB_TAG ('i','d','e','o'),
439   HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_TOP_OR_RIGHT	= HB_TAG ('i','d','t','p'),
440   HB_OT_LAYOUT_BASELINE_TAG_MATH			= HB_TAG ('m','a','t','h'),
441 
442   _HB_OT_LAYOUT_BASELINE_TAG_MAX_VALUE = HB_TAG_MAX_SIGNED /*< skip >*/
443 } hb_ot_layout_baseline_tag_t;
444 
445 HB_EXTERN hb_bool_t
446 hb_ot_layout_get_baseline (hb_font_t                   *font,
447 			   hb_ot_layout_baseline_tag_t  baseline_tag,
448 			   hb_direction_t               direction,
449 			   hb_tag_t                     script_tag,
450 			   hb_tag_t                     language_tag,
451 			   hb_position_t               *coord        /* OUT.  May be NULL. */);
452 
453 
454 HB_END_DECLS
455 
456 #endif /* HB_OT_LAYOUT_H */
457