summaryrefslogtreecommitdiffstats
path: root/src/3rdparty/harfbuzz-ng/src/hb-ot-layout-private.hh
blob: 47fecd216d3045d4909234fcc566823ae710a186 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
/*
 * Copyright © 2007,2008,2009  Red Hat, Inc.
 * Copyright © 2012,2013  Google, Inc.
 *
 *  This is part of HarfBuzz, a text shaping library.
 *
 * Permission is hereby granted, without written agreement and without
 * license or royalty fees, to use, copy, modify, and distribute this
 * software and its documentation for any purpose, provided that the
 * above copyright notice and the following two paragraphs appear in
 * all copies of this software.
 *
 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 *
 * Red Hat Author(s): Behdad Esfahbod
 * Google Author(s): Behdad Esfahbod
 */

#ifndef HB_OT_LAYOUT_PRIVATE_HH
#define HB_OT_LAYOUT_PRIVATE_HH

#include "hb-private.hh"

#include "hb-font-private.hh"
#include "hb-buffer-private.hh"
#include "hb-set-private.hh"


/*
 * GDEF
 */

typedef enum
{
  /* The following three match LookupFlags::Ignore* numbers. */
  HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH	= 0x02u,
  HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE	= 0x04u,
  HB_OT_LAYOUT_GLYPH_PROPS_MARK		= 0x08u,

  /* The following are used internally; not derived from GDEF. */
  HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED	= 0x10u,
  HB_OT_LAYOUT_GLYPH_PROPS_LIGATED	= 0x20u,
  HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED	= 0x40u,

  HB_OT_LAYOUT_GLYPH_PROPS_PRESERVE     = HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED |
					  HB_OT_LAYOUT_GLYPH_PROPS_LIGATED |
					  HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED
} hb_ot_layout_glyph_class_mask_t;


/*
 * GSUB/GPOS
 */

HB_INTERNAL hb_bool_t
hb_ot_layout_lookup_would_substitute_fast (hb_face_t            *face,
					   unsigned int          lookup_index,
					   const hb_codepoint_t *glyphs,
					   unsigned int          glyphs_length,
					   hb_bool_t             zero_context);


/* Should be called before all the substitute_lookup's are done. */
HB_INTERNAL void
hb_ot_layout_substitute_start (hb_font_t    *font,
			       hb_buffer_t  *buffer);


struct hb_ot_layout_lookup_accelerator_t;

namespace OT {
  struct hb_apply_context_t;
  struct SubstLookup;
}

HB_INTERNAL void
hb_ot_layout_substitute_lookup (OT::hb_apply_context_t *c,
				const OT::SubstLookup &lookup,
				const hb_ot_layout_lookup_accelerator_t &accel);


/* Should be called after all the substitute_lookup's are done */
HB_INTERNAL void
hb_ot_layout_substitute_finish (hb_font_t    *font,
				hb_buffer_t  *buffer);


/* Should be called before all the position_lookup's are done.  Resets positions to zero. */
HB_INTERNAL void
hb_ot_layout_position_start (hb_font_t    *font,
			     hb_buffer_t  *buffer);

/* Should be called after all the position_lookup's are done */
HB_INTERNAL void
hb_ot_layout_position_finish (hb_font_t    *font,
			      hb_buffer_t  *buffer);



/*
 * hb_ot_layout_t
 */

namespace OT {
  struct GDEF;
  struct GSUB;
  struct GPOS;
}

struct hb_ot_layout_lookup_accelerator_t
{
  template <typename TLookup>
  inline void init (const TLookup &lookup)
  {
    digest.init ();
    lookup.add_coverage (&digest);
  }

  inline void fini (void)
  {
  }

  inline bool may_have (hb_codepoint_t g) const {
    return digest.may_have (g);
  }

  private:
  hb_set_digest_t digest;
};

struct hb_ot_layout_t
{
  hb_blob_t *gdef_blob;
  hb_blob_t *gsub_blob;
  hb_blob_t *gpos_blob;

  const struct OT::GDEF *gdef;
  const struct OT::GSUB *gsub;
  const struct OT::GPOS *gpos;

  unsigned int gsub_lookup_count;
  unsigned int gpos_lookup_count;

  hb_ot_layout_lookup_accelerator_t *gsub_accels;
  hb_ot_layout_lookup_accelerator_t *gpos_accels;
};


HB_INTERNAL hb_ot_layout_t *
_hb_ot_layout_create (hb_face_t *face);

HB_INTERNAL void
_hb_ot_layout_destroy (hb_ot_layout_t *layout);


#define hb_ot_layout_from_face(face) ((hb_ot_layout_t *) face->shaper_data.ot)


/*
 * Buffer var routines.
 */

/* buffer var allocations, used during the entire shaping process */
#define unicode_props0()	var2.u8[0]
#define unicode_props1()	var2.u8[1]

/* buffer var allocations, used during the GSUB/GPOS processing */
#define glyph_props()		var1.u16[0] /* GDEF glyph properties */
#define lig_props()		var1.u8[2] /* GSUB/GPOS ligature tracking */
#define syllable()		var1.u8[3] /* GSUB/GPOS shaping boundaries */

/* unicode_props */

enum {
  MASK0_ZWJ       = 0x20u,
  MASK0_ZWNJ      = 0x40u,
  MASK0_IGNORABLE = 0x80u,
  MASK0_GEN_CAT   = 0x1Fu
};

static inline void
_hb_glyph_info_set_unicode_props (hb_glyph_info_t *info, hb_unicode_funcs_t *unicode)
{
  /* XXX This shouldn't be inlined, or at least not while is_default_ignorable() is inline. */
  info->unicode_props0() = ((unsigned int) unicode->general_category (info->codepoint)) |
			   (unicode->is_default_ignorable (info->codepoint) ? MASK0_IGNORABLE : 0) |
			   (info->codepoint == 0x200Cu ? MASK0_ZWNJ : 0) |
			   (info->codepoint == 0x200Du ? MASK0_ZWJ : 0);
  info->unicode_props1() = unicode->modified_combining_class (info->codepoint);
}

static inline void
_hb_glyph_info_set_general_category (hb_glyph_info_t *info,
				     hb_unicode_general_category_t gen_cat)
{
  info->unicode_props0() = (unsigned int) gen_cat | ((info->unicode_props0()) & ~MASK0_GEN_CAT);
}

static inline hb_unicode_general_category_t
_hb_glyph_info_get_general_category (const hb_glyph_info_t *info)
{
  return (hb_unicode_general_category_t) (info->unicode_props0() & MASK0_GEN_CAT);
}

static inline void
_hb_glyph_info_set_modified_combining_class (hb_glyph_info_t *info,
					     unsigned int modified_class)
{
  info->unicode_props1() = modified_class;
}

static inline unsigned int
_hb_glyph_info_get_modified_combining_class (const hb_glyph_info_t *info)
{
  return info->unicode_props1();
}

static inline hb_bool_t
_hb_glyph_info_is_default_ignorable (const hb_glyph_info_t *info)
{
  return !!(info->unicode_props0() & MASK0_IGNORABLE);
}

static inline hb_bool_t
_hb_glyph_info_is_zwnj (const hb_glyph_info_t *info)
{
  return !!(info->unicode_props0() & MASK0_ZWNJ);
}

static inline hb_bool_t
_hb_glyph_info_is_zwj (const hb_glyph_info_t *info)
{
  return !!(info->unicode_props0() & MASK0_ZWJ);
}

static inline void
_hb_glyph_info_flip_joiners (hb_glyph_info_t *info)
{
  info->unicode_props0() ^= MASK0_ZWNJ | MASK0_ZWJ;
}

/* lig_props: aka lig_id / lig_comp
 *
 * When a ligature is formed:
 *
 *   - The ligature glyph and any marks in between all the same newly allocated
 *     lig_id,
 *   - The ligature glyph will get lig_num_comps set to the number of components
 *   - The marks get lig_comp > 0, reflecting which component of the ligature
 *     they were applied to.
 *   - This is used in GPOS to attach marks to the right component of a ligature
 *     in MarkLigPos,
 *   - Note that when marks are ligated together, much of the above is skipped
 *     and the current lig_id reused.
 *
 * When a multiple-substitution is done:
 *
 *   - All resulting glyphs will have lig_id = 0,
 *   - The resulting glyphs will have lig_comp = 0, 1, 2, ... respectively.
 *   - This is used in GPOS to attach marks to the first component of a
 *     multiple substitution in MarkBasePos.
 *
 * The numbers are also used in GPOS to do mark-to-mark positioning only
 * to marks that belong to the same component of the same ligature.
 */

static inline void
_hb_glyph_info_clear_lig_props (hb_glyph_info_t *info)
{
  info->lig_props() = 0;
}

#define IS_LIG_BASE 0x10

static inline void
_hb_glyph_info_set_lig_props_for_ligature (hb_glyph_info_t *info,
					   unsigned int lig_id,
					   unsigned int lig_num_comps)
{
  info->lig_props() = (lig_id << 5) | IS_LIG_BASE | (lig_num_comps & 0x0F);
}

static inline void
_hb_glyph_info_set_lig_props_for_mark (hb_glyph_info_t *info,
				       unsigned int lig_id,
				       unsigned int lig_comp)
{
  info->lig_props() = (lig_id << 5) | (lig_comp & 0x0F);
}

static inline void
_hb_glyph_info_set_lig_props_for_component (hb_glyph_info_t *info, unsigned int comp)
{
  _hb_glyph_info_set_lig_props_for_mark (info, 0, comp);
}

static inline unsigned int
_hb_glyph_info_get_lig_id (const hb_glyph_info_t *info)
{
  return info->lig_props() >> 5;
}

static inline bool
_hb_glyph_info_ligated_internal (const hb_glyph_info_t *info)
{
  return !!(info->lig_props() & IS_LIG_BASE);
}

static inline unsigned int
_hb_glyph_info_get_lig_comp (const hb_glyph_info_t *info)
{
  if (_hb_glyph_info_ligated_internal (info))
    return 0;
  else
    return info->lig_props() & 0x0F;
}

static inline unsigned int
_hb_glyph_info_get_lig_num_comps (const hb_glyph_info_t *info)
{
  if ((info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE) &&
      _hb_glyph_info_ligated_internal (info))
    return info->lig_props() & 0x0F;
  else
    return 1;
}

static inline uint8_t
_hb_allocate_lig_id (hb_buffer_t *buffer) {
  uint8_t lig_id = buffer->next_serial () & 0x07;
  if (unlikely (!lig_id))
    lig_id = _hb_allocate_lig_id (buffer); /* in case of overflow */
  return lig_id;
}

/* glyph_props: */

static inline void
_hb_glyph_info_set_glyph_props (hb_glyph_info_t *info, unsigned int props)
{
  info->glyph_props() = props;
}

static inline unsigned int
_hb_glyph_info_get_glyph_props (const hb_glyph_info_t *info)
{
  return info->glyph_props();
}

static inline bool
_hb_glyph_info_is_base_glyph (const hb_glyph_info_t *info)
{
  return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH);
}

static inline bool
_hb_glyph_info_is_ligature (const hb_glyph_info_t *info)
{
  return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE);
}

static inline bool
_hb_glyph_info_is_mark (const hb_glyph_info_t *info)
{
  return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MARK);
}

static inline bool
_hb_glyph_info_substituted (const hb_glyph_info_t *info)
{
  return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED);
}

static inline bool
_hb_glyph_info_ligated (const hb_glyph_info_t *info)
{
  return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATED);
}

static inline bool
_hb_glyph_info_multiplied (const hb_glyph_info_t *info)
{
  return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED);
}

static inline bool
_hb_glyph_info_ligated_and_didnt_multiply (const hb_glyph_info_t *info)
{
  return _hb_glyph_info_ligated (info) && !_hb_glyph_info_multiplied (info);
}

static inline void
_hb_glyph_info_clear_ligated_and_multiplied (hb_glyph_info_t *info)
{
  info->glyph_props() &= ~(HB_OT_LAYOUT_GLYPH_PROPS_LIGATED |
			   HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED);
}


/* Allocation / deallocation. */

static inline void
_hb_buffer_allocate_unicode_vars (hb_buffer_t *buffer)
{
  HB_BUFFER_ALLOCATE_VAR (buffer, unicode_props0);
  HB_BUFFER_ALLOCATE_VAR (buffer, unicode_props1);
}

static inline void
_hb_buffer_deallocate_unicode_vars (hb_buffer_t *buffer)
{
  HB_BUFFER_DEALLOCATE_VAR (buffer, unicode_props0);
  HB_BUFFER_DEALLOCATE_VAR (buffer, unicode_props1);
}

static inline void
_hb_buffer_assert_unicode_vars (hb_buffer_t *buffer)
{
  HB_BUFFER_ASSERT_VAR (buffer, unicode_props0);
  HB_BUFFER_ASSERT_VAR (buffer, unicode_props1);
}

static inline void
_hb_buffer_allocate_gsubgpos_vars (hb_buffer_t *buffer)
{
  HB_BUFFER_ALLOCATE_VAR (buffer, glyph_props);
  HB_BUFFER_ALLOCATE_VAR (buffer, lig_props);
  HB_BUFFER_ALLOCATE_VAR (buffer, syllable);
}

static inline void
_hb_buffer_deallocate_gsubgpos_vars (hb_buffer_t *buffer)
{
  HB_BUFFER_DEALLOCATE_VAR (buffer, syllable);
  HB_BUFFER_DEALLOCATE_VAR (buffer, lig_props);
  HB_BUFFER_DEALLOCATE_VAR (buffer, glyph_props);
}

static inline void
_hb_buffer_assert_gsubgpos_vars (hb_buffer_t *buffer)
{
  HB_BUFFER_ASSERT_VAR (buffer, glyph_props);
  HB_BUFFER_ASSERT_VAR (buffer, lig_props);
  HB_BUFFER_ASSERT_VAR (buffer, syllable);
}

/* Make sure no one directly touches our props... */
#undef unicode_props0
#undef unicode_props1
#undef lig_props
#undef glyph_props


#endif /* HB_OT_LAYOUT_PRIVATE_HH */