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/*
40 * GDEF
41 */
42
43typedef enum
44{
45  /* The following three match LookupFlags::Ignore* numbers. */
46  HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH	= 0x02u,
47  HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE	= 0x04u,
48  HB_OT_LAYOUT_GLYPH_PROPS_MARK		= 0x08u,
49
50  /* The following are used internally; not derived from GDEF. */
51  HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED	= 0x10u,
52  HB_OT_LAYOUT_GLYPH_PROPS_LIGATED	= 0x20u,
53  HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED	= 0x40u,
54
55  HB_OT_LAYOUT_GLYPH_PROPS_PRESERVE     = HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED |
56					  HB_OT_LAYOUT_GLYPH_PROPS_LIGATED |
57					  HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED
58} hb_ot_layout_glyph_class_mask_t;
59
60
61/*
62 * GSUB/GPOS
63 */
64
65HB_INTERNAL hb_bool_t
66hb_ot_layout_lookup_would_substitute_fast (hb_face_t            *face,
67					   unsigned int          lookup_index,
68					   const hb_codepoint_t *glyphs,
69					   unsigned int          glyphs_length,
70					   hb_bool_t             zero_context);
71
72
73/* Should be called before all the substitute_lookup's are done. */
74HB_INTERNAL void
75hb_ot_layout_substitute_start (hb_font_t    *font,
76			       hb_buffer_t  *buffer);
77
78
79struct hb_ot_layout_lookup_accelerator_t;
80
81namespace OT {
82  struct hb_apply_context_t;
83  struct SubstLookup;
84}
85
86HB_INTERNAL void
87hb_ot_layout_substitute_lookup (OT::hb_apply_context_t *c,
88				const OT::SubstLookup &lookup,
89				const hb_ot_layout_lookup_accelerator_t &accel);
90
91
92/* Should be called after all the substitute_lookup's are done */
93HB_INTERNAL void
94hb_ot_layout_substitute_finish (hb_font_t    *font,
95				hb_buffer_t  *buffer);
96
97
98/* Should be called before all the position_lookup's are done.  Resets positions to zero. */
99HB_INTERNAL void
100hb_ot_layout_position_start (hb_font_t    *font,
101			     hb_buffer_t  *buffer);
102
103/* Should be called after all the position_lookup's are done */
104HB_INTERNAL void
105hb_ot_layout_position_finish (hb_font_t    *font,
106			      hb_buffer_t  *buffer);
107
108
109
110/*
111 * hb_ot_layout_t
112 */
113
114namespace OT {
115  struct GDEF;
116  struct GSUB;
117  struct GPOS;
118}
119
120struct hb_ot_layout_lookup_accelerator_t
121{
122  template <typename TLookup>
123  inline void init (const TLookup &lookup)
124  {
125    digest.init ();
126    lookup.add_coverage (&digest);
127  }
128
129  inline void fini (void)
130  {
131  }
132
133  hb_set_digest_t digest;
134};
135
136struct hb_ot_layout_t
137{
138  hb_blob_t *gdef_blob;
139  hb_blob_t *gsub_blob;
140  hb_blob_t *gpos_blob;
141
142  const struct OT::GDEF *gdef;
143  const struct OT::GSUB *gsub;
144  const struct OT::GPOS *gpos;
145
146  unsigned int gsub_lookup_count;
147  unsigned int gpos_lookup_count;
148
149  hb_ot_layout_lookup_accelerator_t *gsub_accels;
150  hb_ot_layout_lookup_accelerator_t *gpos_accels;
151};
152
153
154HB_INTERNAL hb_ot_layout_t *
155_hb_ot_layout_create (hb_face_t *face);
156
157HB_INTERNAL void
158_hb_ot_layout_destroy (hb_ot_layout_t *layout);
159
160
161#define hb_ot_layout_from_face(face) ((hb_ot_layout_t *) face->shaper_data.ot)
162
163
164/*
165 * Buffer var routines.
166 */
167
168/* buffer var allocations, used during the entire shaping process */
169#define unicode_props0()	var2.u8[0]
170#define unicode_props1()	var2.u8[1]
171
172/* buffer var allocations, used during the GSUB/GPOS processing */
173#define glyph_props()		var1.u16[0] /* GDEF glyph properties */
174#define lig_props()		var1.u8[2] /* GSUB/GPOS ligature tracking */
175#define syllable()		var1.u8[3] /* GSUB/GPOS shaping boundaries */
176
177/* unicode_props */
178
179enum {
180  MASK0_ZWJ       = 0x20u,
181  MASK0_ZWNJ      = 0x40u,
182  MASK0_IGNORABLE = 0x80u,
183  MASK0_GEN_CAT   = 0x1Fu
184};
185
186static inline void
187_hb_glyph_info_set_unicode_props (hb_glyph_info_t *info, hb_unicode_funcs_t *unicode)
188{
189  /* XXX This shouldn't be inlined, or at least not while is_default_ignorable() is inline. */
190  info->unicode_props0() = ((unsigned int) unicode->general_category (info->codepoint)) |
191			   (unicode->is_default_ignorable (info->codepoint) ? MASK0_IGNORABLE : 0) |
192			   (info->codepoint == 0x200Cu ? MASK0_ZWNJ : 0) |
193			   (info->codepoint == 0x200Du ? MASK0_ZWJ : 0);
194  info->unicode_props1() = unicode->modified_combining_class (info->codepoint);
195}
196
197static inline void
198_hb_glyph_info_set_general_category (hb_glyph_info_t *info,
199				     hb_unicode_general_category_t gen_cat)
200{
201  info->unicode_props0() = (unsigned int) gen_cat | ((info->unicode_props0()) & ~MASK0_GEN_CAT);
202}
203
204static inline hb_unicode_general_category_t
205_hb_glyph_info_get_general_category (const hb_glyph_info_t *info)
206{
207  return (hb_unicode_general_category_t) (info->unicode_props0() & MASK0_GEN_CAT);
208}
209
210static inline void
211_hb_glyph_info_set_modified_combining_class (hb_glyph_info_t *info,
212					     unsigned int modified_class)
213{
214  info->unicode_props1() = modified_class;
215}
216
217static inline unsigned int
218_hb_glyph_info_get_modified_combining_class (const hb_glyph_info_t *info)
219{
220  return info->unicode_props1();
221}
222
223static inline hb_bool_t
224_hb_glyph_info_is_default_ignorable (const hb_glyph_info_t *info)
225{
226  return !!(info->unicode_props0() & MASK0_IGNORABLE);
227}
228
229static inline hb_bool_t
230_hb_glyph_info_is_zwnj (const hb_glyph_info_t *info)
231{
232  return !!(info->unicode_props0() & MASK0_ZWNJ);
233}
234
235static inline hb_bool_t
236_hb_glyph_info_is_zwj (const hb_glyph_info_t *info)
237{
238  return !!(info->unicode_props0() & MASK0_ZWJ);
239}
240
241static inline void
242_hb_glyph_info_flip_joiners (hb_glyph_info_t *info)
243{
244  info->unicode_props0() ^= MASK0_ZWNJ | MASK0_ZWJ;
245}
246
247/* lig_props: aka lig_id / lig_comp
248 *
249 * When a ligature is formed:
250 *
251 *   - The ligature glyph and any marks in between all the same newly allocated
252 *     lig_id,
253 *   - The ligature glyph will get lig_num_comps set to the number of components
254 *   - The marks get lig_comp > 0, reflecting which component of the ligature
255 *     they were applied to.
256 *   - This is used in GPOS to attach marks to the right component of a ligature
257 *     in MarkLigPos,
258 *   - Note that when marks are ligated together, much of the above is skipped
259 *     and the current lig_id reused.
260 *
261 * When a multiple-substitution is done:
262 *
263 *   - All resulting glyphs will have lig_id = 0,
264 *   - The resulting glyphs will have lig_comp = 0, 1, 2, ... respectively.
265 *   - This is used in GPOS to attach marks to the first component of a
266 *     multiple substitution in MarkBasePos.
267 *
268 * The numbers are also used in GPOS to do mark-to-mark positioning only
269 * to marks that belong to the same component of the same ligature.
270 */
271
272static inline void
273_hb_glyph_info_clear_lig_props (hb_glyph_info_t *info)
274{
275  info->lig_props() = 0;
276}
277
278#define IS_LIG_BASE 0x10
279
280static inline void
281_hb_glyph_info_set_lig_props_for_ligature (hb_glyph_info_t *info,
282					   unsigned int lig_id,
283					   unsigned int lig_num_comps)
284{
285  info->lig_props() = (lig_id << 5) | IS_LIG_BASE | (lig_num_comps & 0x0F);
286}
287
288static inline void
289_hb_glyph_info_set_lig_props_for_mark (hb_glyph_info_t *info,
290				       unsigned int lig_id,
291				       unsigned int lig_comp)
292{
293  info->lig_props() = (lig_id << 5) | (lig_comp & 0x0F);
294}
295
296static inline void
297_hb_glyph_info_set_lig_props_for_component (hb_glyph_info_t *info, unsigned int comp)
298{
299  _hb_glyph_info_set_lig_props_for_mark (info, 0, comp);
300}
301
302static inline unsigned int
303_hb_glyph_info_get_lig_id (const hb_glyph_info_t *info)
304{
305  return info->lig_props() >> 5;
306}
307
308static inline bool
309_hb_glyph_info_ligated_internal (const hb_glyph_info_t *info)
310{
311  return !!(info->lig_props() & IS_LIG_BASE);
312}
313
314static inline unsigned int
315_hb_glyph_info_get_lig_comp (const hb_glyph_info_t *info)
316{
317  if (_hb_glyph_info_ligated_internal (info))
318    return 0;
319  else
320    return info->lig_props() & 0x0F;
321}
322
323static inline unsigned int
324_hb_glyph_info_get_lig_num_comps (const hb_glyph_info_t *info)
325{
326  if ((info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE) &&
327      _hb_glyph_info_ligated_internal (info))
328    return info->lig_props() & 0x0F;
329  else
330    return 1;
331}
332
333static inline uint8_t
334_hb_allocate_lig_id (hb_buffer_t *buffer) {
335  uint8_t lig_id = buffer->next_serial () & 0x07;
336  if (unlikely (!lig_id))
337    lig_id = _hb_allocate_lig_id (buffer); /* in case of overflow */
338  return lig_id;
339}
340
341/* glyph_props: */
342
343static inline void
344_hb_glyph_info_set_glyph_props (hb_glyph_info_t *info, unsigned int props)
345{
346  info->glyph_props() = props;
347}
348
349static inline unsigned int
350_hb_glyph_info_get_glyph_props (const hb_glyph_info_t *info)
351{
352  return info->glyph_props();
353}
354
355static inline bool
356_hb_glyph_info_is_base_glyph (const hb_glyph_info_t *info)
357{
358  return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH);
359}
360
361static inline bool
362_hb_glyph_info_is_ligature (const hb_glyph_info_t *info)
363{
364  return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE);
365}
366
367static inline bool
368_hb_glyph_info_is_mark (const hb_glyph_info_t *info)
369{
370  return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MARK);
371}
372
373static inline bool
374_hb_glyph_info_substituted (const hb_glyph_info_t *info)
375{
376  return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED);
377}
378
379static inline bool
380_hb_glyph_info_ligated (const hb_glyph_info_t *info)
381{
382  return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATED);
383}
384
385static inline bool
386_hb_glyph_info_multiplied (const hb_glyph_info_t *info)
387{
388  return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED);
389}
390
391static inline bool
392_hb_glyph_info_ligated_and_didnt_multiply (const hb_glyph_info_t *info)
393{
394  return _hb_glyph_info_ligated (info) && !_hb_glyph_info_multiplied (info);
395}
396
397static inline void
398_hb_glyph_info_clear_ligated_and_multiplied (hb_glyph_info_t *info)
399{
400  info->glyph_props() &= ~(HB_OT_LAYOUT_GLYPH_PROPS_LIGATED |
401			   HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED);
402}
403
404
405/* Allocation / deallocation. */
406
407static inline void
408_hb_buffer_allocate_unicode_vars (hb_buffer_t *buffer)
409{
410  HB_BUFFER_ALLOCATE_VAR (buffer, unicode_props0);
411  HB_BUFFER_ALLOCATE_VAR (buffer, unicode_props1);
412}
413
414static inline void
415_hb_buffer_deallocate_unicode_vars (hb_buffer_t *buffer)
416{
417  HB_BUFFER_DEALLOCATE_VAR (buffer, unicode_props0);
418  HB_BUFFER_DEALLOCATE_VAR (buffer, unicode_props1);
419}
420
421static inline void
422_hb_buffer_assert_unicode_vars (hb_buffer_t *buffer)
423{
424  HB_BUFFER_ASSERT_VAR (buffer, unicode_props0);
425  HB_BUFFER_ASSERT_VAR (buffer, unicode_props1);
426}
427
428static inline void
429_hb_buffer_allocate_gsubgpos_vars (hb_buffer_t *buffer)
430{
431  HB_BUFFER_ALLOCATE_VAR (buffer, glyph_props);
432  HB_BUFFER_ALLOCATE_VAR (buffer, lig_props);
433  HB_BUFFER_ALLOCATE_VAR (buffer, syllable);
434}
435
436static inline void
437_hb_buffer_deallocate_gsubgpos_vars (hb_buffer_t *buffer)
438{
439  HB_BUFFER_DEALLOCATE_VAR (buffer, syllable);
440  HB_BUFFER_DEALLOCATE_VAR (buffer, lig_props);
441  HB_BUFFER_DEALLOCATE_VAR (buffer, glyph_props);
442}
443
444static inline void
445_hb_buffer_assert_gsubgpos_vars (hb_buffer_t *buffer)
446{
447  HB_BUFFER_ASSERT_VAR (buffer, glyph_props);
448  HB_BUFFER_ASSERT_VAR (buffer, lig_props);
449  HB_BUFFER_ASSERT_VAR (buffer, syllable);
450}
451
452/* Make sure no one directly touches our props... */
453#undef unicode_props0
454#undef unicode_props1
455#undef lig_props
456#undef glyph_props
457
458
459#endif /* HB_OT_LAYOUT_PRIVATE_HH */
460