1 /*
2 * Copyright © 2007,2008,2009 Red Hat, Inc.
3 * Copyright © 2012,2013 Google, Inc.
4 *
5 * This is part of HarfBuzz, a text shaping library.
6 *
7 * Permission is hereby granted, without written agreement and without
8 * license or royalty fees, to use, copy, modify, and distribute this
9 * software and its documentation for any purpose, provided that the
10 * above copyright notice and the following two paragraphs appear in
11 * all copies of this software.
12 *
13 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
14 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
15 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
16 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
17 * DAMAGE.
18 *
19 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
20 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
22 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
23 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
24 *
25 * Red Hat Author(s): Behdad Esfahbod
26 * Google Author(s): Behdad Esfahbod
27 */
28
29 #ifndef HB_OT_LAYOUT_PRIVATE_HH
30 #define HB_OT_LAYOUT_PRIVATE_HH
31
32 #include "hb-private.hh"
33
34 #include "hb-font-private.hh"
35 #include "hb-buffer-private.hh"
36 #include "hb-set-private.hh"
37
38
39 /* Private API corresponding to hb-ot-layout.h: */
40
41 HB_INTERNAL hb_bool_t
42 hb_ot_layout_table_find_feature (hb_face_t *face,
43 hb_tag_t table_tag,
44 hb_tag_t feature_tag,
45 unsigned int *feature_index);
46
47
48 /*
49 * GDEF
50 */
51
52 typedef enum
53 {
54 /* The following three match LookupFlags::Ignore* numbers. */
55 HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH = 0x02u,
56 HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE = 0x04u,
57 HB_OT_LAYOUT_GLYPH_PROPS_MARK = 0x08u,
58
59 /* The following are used internally; not derived from GDEF. */
60 HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED = 0x10u,
61 HB_OT_LAYOUT_GLYPH_PROPS_LIGATED = 0x20u,
62 HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED = 0x40u,
63
64 HB_OT_LAYOUT_GLYPH_PROPS_PRESERVE = HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED |
65 HB_OT_LAYOUT_GLYPH_PROPS_LIGATED |
66 HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED
67 } hb_ot_layout_glyph_class_mask_t;
68
69
70 /*
71 * GSUB/GPOS
72 */
73
74 HB_INTERNAL hb_bool_t
75 hb_ot_layout_lookup_would_substitute_fast (hb_face_t *face,
76 unsigned int lookup_index,
77 const hb_codepoint_t *glyphs,
78 unsigned int glyphs_length,
79 hb_bool_t zero_context);
80
81
82 /* Should be called before all the substitute_lookup's are done. */
83 HB_INTERNAL void
84 hb_ot_layout_substitute_start (hb_font_t *font,
85 hb_buffer_t *buffer);
86
87
88 struct hb_ot_layout_lookup_accelerator_t;
89
90 namespace OT {
91 struct hb_apply_context_t;
92 struct SubstLookup;
93 }
94
95 HB_INTERNAL void
96 hb_ot_layout_substitute_lookup (OT::hb_apply_context_t *c,
97 const OT::SubstLookup &lookup,
98 const hb_ot_layout_lookup_accelerator_t &accel);
99
100
101 /* Should be called after all the substitute_lookup's are done */
102 HB_INTERNAL void
103 hb_ot_layout_substitute_finish (hb_font_t *font,
104 hb_buffer_t *buffer);
105
106
107 /* Should be called before all the position_lookup's are done. Resets positions to zero. */
108 HB_INTERNAL void
109 hb_ot_layout_position_start (hb_font_t *font,
110 hb_buffer_t *buffer);
111
112 /* Should be called after all the position_lookup's are done */
113 HB_INTERNAL void
114 hb_ot_layout_position_finish (hb_font_t *font,
115 hb_buffer_t *buffer);
116
117
118
119 /*
120 * hb_ot_layout_t
121 */
122
123 namespace OT {
124 struct GDEF;
125 struct GSUB;
126 struct GPOS;
127 }
128
129 struct hb_ot_layout_lookup_accelerator_t
130 {
131 template <typename TLookup>
132 inline void init (const TLookup &lookup)
133 {
134 digest.init ();
135 lookup.add_coverage (&digest);
136 }
137
138 inline void fini (void)
139 {
140 }
141
142 inline bool may_have (hb_codepoint_t g) const {
143 return digest.may_have (g);
144 }
145
146 private:
147 hb_set_digest_t digest;
148 };
149
150 struct hb_ot_layout_t
151 {
152 hb_blob_t *gdef_blob;
153 hb_blob_t *gsub_blob;
154 hb_blob_t *gpos_blob;
155
156 const struct OT::GDEF *gdef;
157 const struct OT::GSUB *gsub;
158 const struct OT::GPOS *gpos;
159
160 unsigned int gsub_lookup_count;
161 unsigned int gpos_lookup_count;
162
163 hb_ot_layout_lookup_accelerator_t *gsub_accels;
164 hb_ot_layout_lookup_accelerator_t *gpos_accels;
165 };
166
167
168 HB_INTERNAL hb_ot_layout_t *
169 _hb_ot_layout_create (hb_face_t *face);
170
171 HB_INTERNAL void
172 _hb_ot_layout_destroy (hb_ot_layout_t *layout);
173
174
175 #define hb_ot_layout_from_face(face) ((hb_ot_layout_t *) face->shaper_data.ot)
176
177
178 /*
179 * Buffer var routines.
180 */
181
182 /* buffer var allocations, used during the entire shaping process */
183 #define unicode_props0() var2.u8[0]
184 #define unicode_props1() var2.u8[1]
185
186 /* buffer var allocations, used during the GSUB/GPOS processing */
187 #define glyph_props() var1.u16[0] /* GDEF glyph properties */
188 #define lig_props() var1.u8[2] /* GSUB/GPOS ligature tracking */
189 #define syllable() var1.u8[3] /* GSUB/GPOS shaping boundaries */
190
191
192 /* loop over syllables */
193
194 #define foreach_syllable(buffer, start, end) \
195 for (unsigned int \
196 _count = buffer->len, \
197 start = 0, end = _count ? _next_syllable (buffer, 0) : 0; \
198 start < _count; \
199 start = end, end = _next_syllable (buffer, start))
200
201 static inline unsigned int
202 _next_syllable (hb_buffer_t *buffer, unsigned int start)
203 {
204 hb_glyph_info_t *info = buffer->info;
205 unsigned int count = buffer->len;
206
207 unsigned int syllable = info[start].syllable();
208 while (++start < count && syllable == info[start].syllable())
209 ;
210
211 return start;
212 }
213
214
215 /* unicode_props */
216
217 enum {
218 MASK0_ZWJ = 0x20u,
219 MASK0_ZWNJ = 0x40u,
220 MASK0_IGNORABLE = 0x80u,
221 MASK0_GEN_CAT = 0x1Fu
222 };
223
224 static inline void
225 _hb_glyph_info_set_unicode_props (hb_glyph_info_t *info, hb_unicode_funcs_t *unicode)
226 {
227 /* XXX This shouldn't be inlined, or at least not while is_default_ignorable() is inline. */
228 info->unicode_props0() = ((unsigned int) unicode->general_category (info->codepoint)) |
229 (unicode->is_default_ignorable (info->codepoint) ? MASK0_IGNORABLE : 0) |
230 (info->codepoint == 0x200Cu ? MASK0_ZWNJ : 0) |
231 (info->codepoint == 0x200Du ? MASK0_ZWJ : 0);
232 info->unicode_props1() = unicode->modified_combining_class (info->codepoint);
233 }
234
235 static inline void
236 _hb_glyph_info_set_general_category (hb_glyph_info_t *info,
237 hb_unicode_general_category_t gen_cat)
238 {
239 info->unicode_props0() = (unsigned int) gen_cat | ((info->unicode_props0()) & ~MASK0_GEN_CAT);
240 }
241
242 static inline hb_unicode_general_category_t
243 _hb_glyph_info_get_general_category (const hb_glyph_info_t *info)
244 {
245 return (hb_unicode_general_category_t) (info->unicode_props0() & MASK0_GEN_CAT);
246 }
247
248 static inline void
249 _hb_glyph_info_set_modified_combining_class (hb_glyph_info_t *info,
250 unsigned int modified_class)
251 {
252 info->unicode_props1() = modified_class;
253 }
254
255 static inline unsigned int
256 _hb_glyph_info_get_modified_combining_class (const hb_glyph_info_t *info)
257 {
258 return info->unicode_props1();
259 }
260
261 static inline bool _hb_glyph_info_ligated (const hb_glyph_info_t *info);
262
263 static inline hb_bool_t
264 _hb_glyph_info_is_default_ignorable (const hb_glyph_info_t *info)
265 {
266 return (info->unicode_props0() & MASK0_IGNORABLE) && !_hb_glyph_info_ligated (info);
267 }
268
269 static inline hb_bool_t
270 _hb_glyph_info_is_zwnj (const hb_glyph_info_t *info)
271 {
272 return !!(info->unicode_props0() & MASK0_ZWNJ);
273 }
274
275 static inline hb_bool_t
276 _hb_glyph_info_is_zwj (const hb_glyph_info_t *info)
277 {
278 return !!(info->unicode_props0() & MASK0_ZWJ);
279 }
280
281 static inline void
282 _hb_glyph_info_flip_joiners (hb_glyph_info_t *info)
283 {
284 info->unicode_props0() ^= MASK0_ZWNJ | MASK0_ZWJ;
285 }
286
287 /* lig_props: aka lig_id / lig_comp
288 *
289 * When a ligature is formed:
290 *
291 * - The ligature glyph and any marks in between all the same newly allocated
292 * lig_id,
293 * - The ligature glyph will get lig_num_comps set to the number of components
294 * - The marks get lig_comp > 0, reflecting which component of the ligature
295 * they were applied to.
296 * - This is used in GPOS to attach marks to the right component of a ligature
297 * in MarkLigPos,
298 * - Note that when marks are ligated together, much of the above is skipped
299 * and the current lig_id reused.
300 *
301 * When a multiple-substitution is done:
302 *
303 * - All resulting glyphs will have lig_id = 0,
304 * - The resulting glyphs will have lig_comp = 0, 1, 2, ... respectively.
305 * - This is used in GPOS to attach marks to the first component of a
306 * multiple substitution in MarkBasePos.
307 *
308 * The numbers are also used in GPOS to do mark-to-mark positioning only
309 * to marks that belong to the same component of the same ligature.
310 */
311
312 static inline void
313 _hb_glyph_info_clear_lig_props (hb_glyph_info_t *info)
314 {
315 info->lig_props() = 0;
316 }
317
318 #define IS_LIG_BASE 0x10
319
320 static inline void
321 _hb_glyph_info_set_lig_props_for_ligature (hb_glyph_info_t *info,
322 unsigned int lig_id,
323 unsigned int lig_num_comps)
324 {
325 info->lig_props() = (lig_id << 5) | IS_LIG_BASE | (lig_num_comps & 0x0F);
326 }
327
328 static inline void
329 _hb_glyph_info_set_lig_props_for_mark (hb_glyph_info_t *info,
330 unsigned int lig_id,
331 unsigned int lig_comp)
332 {
333 info->lig_props() = (lig_id << 5) | (lig_comp & 0x0F);
334 }
335
336 static inline void
337 _hb_glyph_info_set_lig_props_for_component (hb_glyph_info_t *info, unsigned int comp)
338 {
339 _hb_glyph_info_set_lig_props_for_mark (info, 0, comp);
340 }
341
342 static inline unsigned int
343 _hb_glyph_info_get_lig_id (const hb_glyph_info_t *info)
344 {
345 return info->lig_props() >> 5;
346 }
347
348 static inline bool
349 _hb_glyph_info_ligated_internal (const hb_glyph_info_t *info)
350 {
351 return !!(info->lig_props() & IS_LIG_BASE);
352 }
353
354 static inline unsigned int
355 _hb_glyph_info_get_lig_comp (const hb_glyph_info_t *info)
356 {
357 if (_hb_glyph_info_ligated_internal (info))
358 return 0;
359 else
360 return info->lig_props() & 0x0F;
361 }
362
363 static inline unsigned int
364 _hb_glyph_info_get_lig_num_comps (const hb_glyph_info_t *info)
365 {
366 if ((info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE) &&
367 _hb_glyph_info_ligated_internal (info))
368 return info->lig_props() & 0x0F;
369 else
370 return 1;
371 }
372
373 static inline uint8_t
374 _hb_allocate_lig_id (hb_buffer_t *buffer) {
375 uint8_t lig_id = buffer->next_serial () & 0x07;
376 if (unlikely (!lig_id))
377 lig_id = _hb_allocate_lig_id (buffer); /* in case of overflow */
378 return lig_id;
379 }
380
381 /* glyph_props: */
382
383 static inline void
384 _hb_glyph_info_set_glyph_props (hb_glyph_info_t *info, unsigned int props)
385 {
386 info->glyph_props() = props;
387 }
388
389 static inline unsigned int
390 _hb_glyph_info_get_glyph_props (const hb_glyph_info_t *info)
391 {
392 return info->glyph_props();
393 }
394
395 static inline bool
396 _hb_glyph_info_is_base_glyph (const hb_glyph_info_t *info)
397 {
398 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH);
399 }
400
401 static inline bool
402 _hb_glyph_info_is_ligature (const hb_glyph_info_t *info)
403 {
404 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE);
405 }
406
407 static inline bool
408 _hb_glyph_info_is_mark (const hb_glyph_info_t *info)
409 {
410 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MARK);
411 }
412
413 static inline bool
414 _hb_glyph_info_substituted (const hb_glyph_info_t *info)
415 {
416 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED);
417 }
418
419 static inline bool
420 _hb_glyph_info_ligated (const hb_glyph_info_t *info)
421 {
422 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATED);
423 }
424
425 static inline bool
426 _hb_glyph_info_multiplied (const hb_glyph_info_t *info)
427 {
428 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED);
429 }
430
431 static inline bool
432 _hb_glyph_info_ligated_and_didnt_multiply (const hb_glyph_info_t *info)
433 {
434 return _hb_glyph_info_ligated (info) && !_hb_glyph_info_multiplied (info);
435 }
436
437 static inline void
438 _hb_glyph_info_clear_ligated_and_multiplied (hb_glyph_info_t *info)
439 {
440 info->glyph_props() &= ~(HB_OT_LAYOUT_GLYPH_PROPS_LIGATED |
441 HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED);
442 }
443
444 static inline void
445 _hb_glyph_info_clear_substituted_and_ligated_and_multiplied (hb_glyph_info_t *info)
446 {
447 info->glyph_props() &= ~(HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED |
448 HB_OT_LAYOUT_GLYPH_PROPS_LIGATED |
449 HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED);
450 }
451
452
453 /* Allocation / deallocation. */
454
455 static inline void
456 _hb_buffer_allocate_unicode_vars (hb_buffer_t *buffer)
457 {
458 HB_BUFFER_ALLOCATE_VAR (buffer, unicode_props0);
459 HB_BUFFER_ALLOCATE_VAR (buffer, unicode_props1);
460 }
461
462 static inline void
463 _hb_buffer_deallocate_unicode_vars (hb_buffer_t *buffer)
464 {
465 HB_BUFFER_DEALLOCATE_VAR (buffer, unicode_props0);
466 HB_BUFFER_DEALLOCATE_VAR (buffer, unicode_props1);
467 }
468
469 static inline void
470 _hb_buffer_assert_unicode_vars (hb_buffer_t *buffer)
471 {
472 HB_BUFFER_ASSERT_VAR (buffer, unicode_props0);
473 HB_BUFFER_ASSERT_VAR (buffer, unicode_props1);
474 }
475
476 static inline void
477 _hb_buffer_allocate_gsubgpos_vars (hb_buffer_t *buffer)
478 {
479 HB_BUFFER_ALLOCATE_VAR (buffer, glyph_props);
480 HB_BUFFER_ALLOCATE_VAR (buffer, lig_props);
481 HB_BUFFER_ALLOCATE_VAR (buffer, syllable);
482 }
483
484 static inline void
485 _hb_buffer_deallocate_gsubgpos_vars (hb_buffer_t *buffer)
486 {
487 HB_BUFFER_DEALLOCATE_VAR (buffer, syllable);
488 HB_BUFFER_DEALLOCATE_VAR (buffer, lig_props);
489 HB_BUFFER_DEALLOCATE_VAR (buffer, glyph_props);
490 }
491
492 static inline void
493 _hb_buffer_assert_gsubgpos_vars (hb_buffer_t *buffer)
494 {
495 HB_BUFFER_ASSERT_VAR (buffer, glyph_props);
496 HB_BUFFER_ASSERT_VAR (buffer, lig_props);
497 HB_BUFFER_ASSERT_VAR (buffer, syllable);
498 }
499
500 /* Make sure no one directly touches our props... */
501 #undef unicode_props0
502 #undef unicode_props1
503 #undef lig_props
504 #undef glyph_props
505
506
507 #endif /* HB_OT_LAYOUT_PRIVATE_HH */