2 * Copyright © 2007,2008,2009 Red Hat, Inc.
3 * Copyright © 2012,2013 Google, Inc.
5 * This is part of HarfBuzz, a text shaping library.
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.
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
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.
25 * Red Hat Author(s): Behdad Esfahbod
26 * Google Author(s): Behdad Esfahbod
29 #ifndef HB_OT_LAYOUT_HH
30 #define HB_OT_LAYOUT_HH
35 #include "hb-buffer.hh"
36 #include "hb-open-type.hh"
37 #include "hb-ot-shape.hh"
38 #include "hb-set-digest.hh"
41 struct hb_ot_shape_plan_t;
49 hb_ot_layout_has_kerning (hb_face_t *face);
52 hb_ot_layout_has_machine_kerning (hb_face_t *face);
55 hb_ot_layout_has_cross_kerning (hb_face_t *face);
58 hb_ot_layout_kern (const hb_ot_shape_plan_t *plan,
63 /* Private API corresponding to hb-ot-layout.h: */
66 hb_ot_layout_table_find_feature (hb_face_t *face,
69 unsigned int *feature_index);
76 enum hb_ot_layout_glyph_props_flags_t
78 /* The following three match LookupFlags::Ignore* numbers. */
79 HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH = 0x02u,
80 HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE = 0x04u,
81 HB_OT_LAYOUT_GLYPH_PROPS_MARK = 0x08u,
83 /* The following are used internally; not derived from GDEF. */
84 HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED = 0x10u,
85 HB_OT_LAYOUT_GLYPH_PROPS_LIGATED = 0x20u,
86 HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED = 0x40u,
88 HB_OT_LAYOUT_GLYPH_PROPS_PRESERVE = HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED |
89 HB_OT_LAYOUT_GLYPH_PROPS_LIGATED |
90 HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED
92 HB_MARK_AS_FLAG_T (hb_ot_layout_glyph_props_flags_t);
100 /* Should be called before all the substitute_lookup's are done. */
102 hb_ot_layout_substitute_start (hb_font_t *font,
103 hb_buffer_t *buffer);
106 hb_ot_layout_delete_glyphs_inplace (hb_buffer_t *buffer,
107 bool (*filter) (const hb_glyph_info_t *info));
110 struct hb_ot_apply_context_t;
112 struct hb_ot_layout_lookup_accelerator_t;
116 hb_ot_layout_substitute_lookup (OT::hb_ot_apply_context_t *c,
117 const OT::SubstLookup &lookup,
118 const OT::hb_ot_layout_lookup_accelerator_t &accel);
121 /* Should be called before all the position_lookup's are done. */
123 hb_ot_layout_position_start (hb_font_t *font,
124 hb_buffer_t *buffer);
126 /* Should be called after all the position_lookup's are done, to fini advances. */
128 hb_ot_layout_position_finish_advances (hb_font_t *font,
129 hb_buffer_t *buffer);
131 /* Should be called after hb_ot_layout_position_finish_advances, to fini offsets. */
133 hb_ot_layout_position_finish_offsets (hb_font_t *font,
134 hb_buffer_t *buffer);
138 * Buffer var routines.
141 /* buffer var allocations, used during the entire shaping process */
142 #define unicode_props() var2.u16[0]
144 /* buffer var allocations, used during the GSUB/GPOS processing */
145 #define glyph_props() var1.u16[0] /* GDEF glyph properties */
146 #define lig_props() var1.u8[2] /* GSUB/GPOS ligature tracking */
147 #define syllable() var1.u8[3] /* GSUB/GPOS shaping boundaries */
150 /* Loop over syllables. Based on foreach_cluster(). */
151 #define foreach_syllable(buffer, start, end) \
153 _count = buffer->len, \
154 start = 0, end = _count ? _hb_next_syllable (buffer, 0) : 0; \
156 start = end, end = _hb_next_syllable (buffer, start))
158 static inline unsigned int
159 _hb_next_syllable (hb_buffer_t *buffer, unsigned int start)
161 hb_glyph_info_t *info = buffer->info;
162 unsigned int count = buffer->len;
164 unsigned int syllable = info[start].syllable();
165 while (++start < count && syllable == info[start].syllable())
175 * unicode_props() is a two-byte number. The low byte includes:
176 * - General_Category: 5 bits.
178 * * Is it Default_Ignorable(); we have a modified Default_Ignorable().
179 * * Whether it's one of the three Mongolian Free Variation Selectors,
180 * CGJ, or other characters that are hidden but should not be ignored
181 * like most other Default_Ignorable()s do during matching.
182 * * Whether it's a grapheme continuation.
184 * The high-byte has different meanings, switched by the Gen-Cat:
185 * - For Mn,Mc,Me: the modified Combining_Class.
186 * - For Cf: whether it's ZWJ, ZWNJ, or something else.
187 * - For Ws: index of which space character this is, if space fallback
188 * is needed, ie. we don't set this by default, only if asked to.
191 enum hb_unicode_props_flags_t {
192 UPROPS_MASK_GEN_CAT = 0x001Fu,
193 UPROPS_MASK_IGNORABLE = 0x0020u,
194 UPROPS_MASK_HIDDEN = 0x0040u, /* MONGOLIAN FREE VARIATION SELECTOR 1..3, or TAG characters */
195 UPROPS_MASK_CONTINUATION=0x0080u,
197 /* If GEN_CAT=FORMAT, top byte masks: */
198 UPROPS_MASK_Cf_ZWJ = 0x0100u,
199 UPROPS_MASK_Cf_ZWNJ = 0x0200u
201 HB_MARK_AS_FLAG_T (hb_unicode_props_flags_t);
204 _hb_glyph_info_set_unicode_props (hb_glyph_info_t *info, hb_buffer_t *buffer)
206 hb_unicode_funcs_t *unicode = buffer->unicode;
207 unsigned int u = info->codepoint;
208 unsigned int gen_cat = (unsigned int) unicode->general_category (u);
209 unsigned int props = gen_cat;
213 buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII;
215 if (unlikely (unicode->is_default_ignorable (u)))
217 buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES;
218 props |= UPROPS_MASK_IGNORABLE;
219 if (u == 0x200Cu) props |= UPROPS_MASK_Cf_ZWNJ;
220 else if (u == 0x200Du) props |= UPROPS_MASK_Cf_ZWJ;
221 /* Mongolian Free Variation Selectors need to be remembered
222 * because although we need to hide them like default-ignorables,
223 * they need to non-ignorable during shaping. This is similar to
224 * what we do for joiners in Indic-like shapers, but since the
225 * FVSes are GC=Mn, we have use a separate bit to remember them.
227 * https://github.com/harfbuzz/harfbuzz/issues/234 */
228 else if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x180Bu, 0x180Du))) props |= UPROPS_MASK_HIDDEN;
229 /* TAG characters need similar treatment. Fixes:
230 * https://github.com/harfbuzz/harfbuzz/issues/463 */
231 else if (unlikely (hb_in_range<hb_codepoint_t> (u, 0xE0020u, 0xE007Fu))) props |= UPROPS_MASK_HIDDEN;
232 /* COMBINING GRAPHEME JOINER should not be skipped; at least some times.
233 * https://github.com/harfbuzz/harfbuzz/issues/554 */
234 else if (unlikely (u == 0x034Fu))
236 buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_CGJ;
237 props |= UPROPS_MASK_HIDDEN;
241 if (unlikely (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (gen_cat)))
243 props |= UPROPS_MASK_CONTINUATION;
244 props |= unicode->modified_combining_class (u)<<8;
248 info->unicode_props() = props;
252 _hb_glyph_info_set_general_category (hb_glyph_info_t *info,
253 hb_unicode_general_category_t gen_cat)
255 /* Clears top-byte. */
256 info->unicode_props() = (unsigned int) gen_cat | (info->unicode_props() & (0xFF & ~UPROPS_MASK_GEN_CAT));
259 static inline hb_unicode_general_category_t
260 _hb_glyph_info_get_general_category (const hb_glyph_info_t *info)
262 return (hb_unicode_general_category_t) (info->unicode_props() & UPROPS_MASK_GEN_CAT);
266 _hb_glyph_info_is_unicode_mark (const hb_glyph_info_t *info)
268 return HB_UNICODE_GENERAL_CATEGORY_IS_MARK (info->unicode_props() & UPROPS_MASK_GEN_CAT);
271 _hb_glyph_info_set_modified_combining_class (hb_glyph_info_t *info,
272 unsigned int modified_class)
274 if (unlikely (!_hb_glyph_info_is_unicode_mark (info)))
276 info->unicode_props() = (modified_class<<8) | (info->unicode_props() & 0xFF);
278 static inline unsigned int
279 _hb_glyph_info_get_modified_combining_class (const hb_glyph_info_t *info)
281 return _hb_glyph_info_is_unicode_mark (info) ? info->unicode_props()>>8 : 0;
283 #define info_cc(info) (_hb_glyph_info_get_modified_combining_class (&(info)))
286 _hb_glyph_info_is_unicode_space (const hb_glyph_info_t *info)
288 return _hb_glyph_info_get_general_category (info) ==
289 HB_UNICODE_GENERAL_CATEGORY_SPACE_SEPARATOR;
292 _hb_glyph_info_set_unicode_space_fallback_type (hb_glyph_info_t *info, hb_unicode_funcs_t::space_t s)
294 if (unlikely (!_hb_glyph_info_is_unicode_space (info)))
296 info->unicode_props() = (((unsigned int) s)<<8) | (info->unicode_props() & 0xFF);
298 static inline hb_unicode_funcs_t::space_t
299 _hb_glyph_info_get_unicode_space_fallback_type (const hb_glyph_info_t *info)
301 return _hb_glyph_info_is_unicode_space (info) ?
302 (hb_unicode_funcs_t::space_t) (info->unicode_props()>>8) :
303 hb_unicode_funcs_t::NOT_SPACE;
306 static inline bool _hb_glyph_info_ligated (const hb_glyph_info_t *info);
309 _hb_glyph_info_is_default_ignorable (const hb_glyph_info_t *info)
311 return (info->unicode_props() & UPROPS_MASK_IGNORABLE) &&
312 !_hb_glyph_info_ligated (info);
315 _hb_glyph_info_is_default_ignorable_and_not_hidden (const hb_glyph_info_t *info)
317 return ((info->unicode_props() & (UPROPS_MASK_IGNORABLE|UPROPS_MASK_HIDDEN))
318 == UPROPS_MASK_IGNORABLE) &&
319 !_hb_glyph_info_ligated (info);
322 _hb_glyph_info_unhide (hb_glyph_info_t *info)
324 info->unicode_props() &= ~ UPROPS_MASK_HIDDEN;
328 _hb_glyph_info_set_continuation (hb_glyph_info_t *info)
330 info->unicode_props() |= UPROPS_MASK_CONTINUATION;
333 _hb_glyph_info_reset_continuation (hb_glyph_info_t *info)
335 info->unicode_props() &= ~ UPROPS_MASK_CONTINUATION;
338 _hb_glyph_info_is_continuation (const hb_glyph_info_t *info)
340 return info->unicode_props() & UPROPS_MASK_CONTINUATION;
342 /* Loop over grapheme. Based on foreach_cluster(). */
343 #define foreach_grapheme(buffer, start, end) \
345 _count = buffer->len, \
346 start = 0, end = _count ? _hb_next_grapheme (buffer, 0) : 0; \
348 start = end, end = _hb_next_grapheme (buffer, start))
350 static inline unsigned int
351 _hb_next_grapheme (hb_buffer_t *buffer, unsigned int start)
353 hb_glyph_info_t *info = buffer->info;
354 unsigned int count = buffer->len;
356 while (++start < count && _hb_glyph_info_is_continuation (&info[start]))
363 _hb_glyph_info_is_unicode_format (const hb_glyph_info_t *info)
365 return _hb_glyph_info_get_general_category (info) ==
366 HB_UNICODE_GENERAL_CATEGORY_FORMAT;
369 _hb_glyph_info_is_zwnj (const hb_glyph_info_t *info)
371 return _hb_glyph_info_is_unicode_format (info) && (info->unicode_props() & UPROPS_MASK_Cf_ZWNJ);
374 _hb_glyph_info_is_zwj (const hb_glyph_info_t *info)
376 return _hb_glyph_info_is_unicode_format (info) && (info->unicode_props() & UPROPS_MASK_Cf_ZWJ);
379 _hb_glyph_info_is_joiner (const hb_glyph_info_t *info)
381 return _hb_glyph_info_is_unicode_format (info) && (info->unicode_props() & (UPROPS_MASK_Cf_ZWNJ|UPROPS_MASK_Cf_ZWJ));
384 _hb_glyph_info_flip_joiners (hb_glyph_info_t *info)
386 if (!_hb_glyph_info_is_unicode_format (info))
388 info->unicode_props() ^= UPROPS_MASK_Cf_ZWNJ | UPROPS_MASK_Cf_ZWJ;
391 /* lig_props: aka lig_id / lig_comp
393 * When a ligature is formed:
395 * - The ligature glyph and any marks in between all the same newly allocated
397 * - The ligature glyph will get lig_num_comps set to the number of components
398 * - The marks get lig_comp > 0, reflecting which component of the ligature
399 * they were applied to.
400 * - This is used in GPOS to attach marks to the right component of a ligature
402 * - Note that when marks are ligated together, much of the above is skipped
403 * and the current lig_id reused.
405 * When a multiple-substitution is done:
407 * - All resulting glyphs will have lig_id = 0,
408 * - The resulting glyphs will have lig_comp = 0, 1, 2, ... respectively.
409 * - This is used in GPOS to attach marks to the first component of a
410 * multiple substitution in MarkBasePos.
412 * The numbers are also used in GPOS to do mark-to-mark positioning only
413 * to marks that belong to the same component of the same ligature.
417 _hb_glyph_info_clear_lig_props (hb_glyph_info_t *info)
419 info->lig_props() = 0;
422 #define IS_LIG_BASE 0x10
425 _hb_glyph_info_set_lig_props_for_ligature (hb_glyph_info_t *info,
427 unsigned int lig_num_comps)
429 info->lig_props() = (lig_id << 5) | IS_LIG_BASE | (lig_num_comps & 0x0F);
433 _hb_glyph_info_set_lig_props_for_mark (hb_glyph_info_t *info,
435 unsigned int lig_comp)
437 info->lig_props() = (lig_id << 5) | (lig_comp & 0x0F);
441 _hb_glyph_info_set_lig_props_for_component (hb_glyph_info_t *info, unsigned int comp)
443 _hb_glyph_info_set_lig_props_for_mark (info, 0, comp);
446 static inline unsigned int
447 _hb_glyph_info_get_lig_id (const hb_glyph_info_t *info)
449 return info->lig_props() >> 5;
453 _hb_glyph_info_ligated_internal (const hb_glyph_info_t *info)
455 return !!(info->lig_props() & IS_LIG_BASE);
458 static inline unsigned int
459 _hb_glyph_info_get_lig_comp (const hb_glyph_info_t *info)
461 if (_hb_glyph_info_ligated_internal (info))
464 return info->lig_props() & 0x0F;
467 static inline unsigned int
468 _hb_glyph_info_get_lig_num_comps (const hb_glyph_info_t *info)
470 if ((info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE) &&
471 _hb_glyph_info_ligated_internal (info))
472 return info->lig_props() & 0x0F;
477 static inline uint8_t
478 _hb_allocate_lig_id (hb_buffer_t *buffer) {
479 uint8_t lig_id = buffer->next_serial () & 0x07;
480 if (unlikely (!lig_id))
481 lig_id = _hb_allocate_lig_id (buffer); /* in case of overflow */
488 _hb_glyph_info_set_glyph_props (hb_glyph_info_t *info, unsigned int props)
490 info->glyph_props() = props;
493 static inline unsigned int
494 _hb_glyph_info_get_glyph_props (const hb_glyph_info_t *info)
496 return info->glyph_props();
500 _hb_glyph_info_is_base_glyph (const hb_glyph_info_t *info)
502 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH);
506 _hb_glyph_info_is_ligature (const hb_glyph_info_t *info)
508 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE);
512 _hb_glyph_info_is_mark (const hb_glyph_info_t *info)
514 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MARK);
518 _hb_glyph_info_substituted (const hb_glyph_info_t *info)
520 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED);
524 _hb_glyph_info_ligated (const hb_glyph_info_t *info)
526 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATED);
530 _hb_glyph_info_multiplied (const hb_glyph_info_t *info)
532 return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED);
536 _hb_glyph_info_ligated_and_didnt_multiply (const hb_glyph_info_t *info)
538 return _hb_glyph_info_ligated (info) && !_hb_glyph_info_multiplied (info);
542 _hb_glyph_info_clear_ligated_and_multiplied (hb_glyph_info_t *info)
544 info->glyph_props() &= ~(HB_OT_LAYOUT_GLYPH_PROPS_LIGATED |
545 HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED);
549 _hb_glyph_info_clear_substituted (hb_glyph_info_t *info)
551 info->glyph_props() &= ~(HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED);
555 /* Allocation / deallocation. */
558 _hb_buffer_allocate_unicode_vars (hb_buffer_t *buffer)
560 HB_BUFFER_ALLOCATE_VAR (buffer, unicode_props);
564 _hb_buffer_deallocate_unicode_vars (hb_buffer_t *buffer)
566 HB_BUFFER_DEALLOCATE_VAR (buffer, unicode_props);
570 _hb_buffer_assert_unicode_vars (hb_buffer_t *buffer)
572 HB_BUFFER_ASSERT_VAR (buffer, unicode_props);
576 _hb_buffer_allocate_gsubgpos_vars (hb_buffer_t *buffer)
578 HB_BUFFER_ALLOCATE_VAR (buffer, glyph_props);
579 HB_BUFFER_ALLOCATE_VAR (buffer, lig_props);
580 HB_BUFFER_ALLOCATE_VAR (buffer, syllable);
584 _hb_buffer_deallocate_gsubgpos_vars (hb_buffer_t *buffer)
586 HB_BUFFER_DEALLOCATE_VAR (buffer, syllable);
587 HB_BUFFER_DEALLOCATE_VAR (buffer, lig_props);
588 HB_BUFFER_DEALLOCATE_VAR (buffer, glyph_props);
592 _hb_buffer_assert_gsubgpos_vars (hb_buffer_t *buffer)
594 HB_BUFFER_ASSERT_VAR (buffer, glyph_props);
595 HB_BUFFER_ASSERT_VAR (buffer, lig_props);
596 HB_BUFFER_ASSERT_VAR (buffer, syllable);
599 /* Make sure no one directly touches our props... */
600 #undef unicode_props0
601 #undef unicode_props1
605 #endif /* HB_OT_LAYOUT_HH */