xref: /aosp_15_r20/external/harfbuzz_ng/src/hb-ot-shaper-use-machine.rl (revision 2d1272b857b1f7575e6e246373e1cb218663db8a)
1/*
2 * Copyright © 2015  Mozilla Foundation.
3 * Copyright © 2015  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 * Mozilla Author(s): Jonathan Kew
26 * Google Author(s): Behdad Esfahbod
27 */
28
29#ifndef HB_OT_SHAPER_USE_MACHINE_HH
30#define HB_OT_SHAPER_USE_MACHINE_HH
31
32#include "hb.hh"
33
34#include "hb-ot-shaper-syllabic.hh"
35
36/* buffer var allocations */
37#define use_category() ot_shaper_var_u8_category()
38
39#define USE(Cat) use_syllable_machine_ex_##Cat
40
41enum use_syllable_type_t {
42  use_virama_terminated_cluster,
43  use_sakot_terminated_cluster,
44  use_standard_cluster,
45  use_number_joiner_terminated_cluster,
46  use_numeral_cluster,
47  use_symbol_cluster,
48  use_hieroglyph_cluster,
49  use_broken_cluster,
50  use_non_cluster,
51};
52
53%%{
54  machine use_syllable_machine;
55  alphtype unsigned char;
56  write exports;
57  write data;
58}%%
59
60%%{
61
62# Categories used in the Universal Shaping Engine spec:
63# https://docs.microsoft.com/en-us/typography/script-development/use
64
65export O	= 0; # OTHER
66
67export B	= 1; # BASE
68export N	= 4; # BASE_NUM
69export GB	= 5; # BASE_OTHER
70export CGJ	= 6; # CGJ
71export SUB	= 11; # CONS_SUB
72export H	= 12; # HALANT
73
74export HN	= 13; # HALANT_NUM
75export ZWNJ	= 14; # Zero width non-joiner
76export WJ	= 16; # Word joiner
77export R	= 18; # REPHA
78export CS	= 43; # CONS_WITH_STACKER
79export IS	= 44; # INVISIBLE_STACKER
80export Sk	= 48; # SAKOT
81export G	= 49; # HIEROGLYPH
82export J	= 50; # HIEROGLYPH_JOINER
83export SB	= 51; # HIEROGLYPH_SEGMENT_BEGIN
84export SE	= 52; # HIEROGLYPH_SEGMENT_END
85export HVM	= 53; # HALANT_OR_VOWEL_MODIFIER
86export HM	= 54; # HIEROGLYPH_MOD
87export HR	= 55; # HIEROGLYPH_MIRROR
88export RK	= 56; # REORDERING_KILLER
89
90export FAbv	= 24; # CONS_FINAL_ABOVE
91export FBlw	= 25; # CONS_FINAL_BELOW
92export FPst	= 26; # CONS_FINAL_POST
93export MAbv	= 27; # CONS_MED_ABOVE
94export MBlw	= 28; # CONS_MED_BELOW
95export MPst	= 29; # CONS_MED_POST
96export MPre	= 30; # CONS_MED_PRE
97export CMAbv	= 31; # CONS_MOD_ABOVE
98export CMBlw	= 32; # CONS_MOD_BELOW
99export VAbv	= 33; # VOWEL_ABOVE / VOWEL_ABOVE_BELOW / VOWEL_ABOVE_BELOW_POST / VOWEL_ABOVE_POST
100export VBlw	= 34; # VOWEL_BELOW / VOWEL_BELOW_POST
101export VPst	= 35; # VOWEL_POST	UIPC = Right
102export VPre	= 22; # VOWEL_PRE / VOWEL_PRE_ABOVE / VOWEL_PRE_ABOVE_POST / VOWEL_PRE_POST
103export VMAbv	= 37; # VOWEL_MOD_ABOVE
104export VMBlw	= 38; # VOWEL_MOD_BELOW
105export VMPst	= 39; # VOWEL_MOD_POST
106export VMPre	= 23; # VOWEL_MOD_PRE
107export SMAbv	= 41; # SYM_MOD_ABOVE
108export SMBlw	= 42; # SYM_MOD_BELOW
109export FMAbv	= 45; # CONS_FINAL_MOD	UIPC = Top
110export FMBlw	= 46; # CONS_FINAL_MOD	UIPC = Bottom
111export FMPst	= 47; # CONS_FINAL_MOD	UIPC = Not_Applicable
112
113
114h = H | HVM | IS | Sk;
115
116consonant_modifiers = CMAbv* CMBlw* ((h B | SUB) CMAbv* CMBlw*)*;
117medial_consonants = MPre? MAbv? MBlw? MPst?;
118dependent_vowels = VPre* VAbv* VBlw* VPst* | H;
119vowel_modifiers = HVM? VMPre* VMAbv* VMBlw* VMPst*;
120final_consonants = FAbv* FBlw* FPst*;
121final_modifiers = FMAbv* FMBlw* | FMPst?;
122
123complex_syllable_start = (R | CS)? (B | GB);
124complex_syllable_middle =
125	consonant_modifiers
126	medial_consonants
127	dependent_vowels
128	vowel_modifiers
129	(Sk B)*
130;
131complex_syllable_tail =
132	complex_syllable_middle
133	final_consonants
134	final_modifiers
135;
136number_joiner_terminated_cluster_tail = (HN N)* HN;
137numeral_cluster_tail = (HN N)+;
138symbol_cluster_tail = SMAbv+ SMBlw* | SMBlw+;
139
140virama_terminated_cluster_tail =
141	consonant_modifiers
142	(IS | RK)
143;
144virama_terminated_cluster =
145	complex_syllable_start
146	virama_terminated_cluster_tail
147;
148sakot_terminated_cluster_tail =
149	complex_syllable_middle
150	Sk
151;
152sakot_terminated_cluster =
153	complex_syllable_start
154	sakot_terminated_cluster_tail
155;
156standard_cluster =
157	complex_syllable_start
158	complex_syllable_tail
159;
160tail = complex_syllable_tail | sakot_terminated_cluster_tail | symbol_cluster_tail | virama_terminated_cluster_tail;
161broken_cluster =
162	R?
163	(tail | number_joiner_terminated_cluster_tail | numeral_cluster_tail)
164;
165
166number_joiner_terminated_cluster = N number_joiner_terminated_cluster_tail;
167numeral_cluster = N numeral_cluster_tail?;
168symbol_cluster = (O | GB | SB) tail?;
169hieroglyph_cluster = SB* G HR? HM? SE* (J SB* (G HR? HM? SE*)?)*;
170other = any;
171
172main := |*
173	virama_terminated_cluster ZWNJ?		=> { found_syllable (use_virama_terminated_cluster); };
174	sakot_terminated_cluster ZWNJ?		=> { found_syllable (use_sakot_terminated_cluster); };
175	standard_cluster ZWNJ?			=> { found_syllable (use_standard_cluster); };
176	number_joiner_terminated_cluster ZWNJ?	=> { found_syllable (use_number_joiner_terminated_cluster); };
177	numeral_cluster ZWNJ?			=> { found_syllable (use_numeral_cluster); };
178	symbol_cluster ZWNJ?			=> { found_syllable (use_symbol_cluster); };
179	hieroglyph_cluster ZWNJ?		=> { found_syllable (use_hieroglyph_cluster); };
180	broken_cluster ZWNJ?			=> { found_syllable (use_broken_cluster); buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_BROKEN_SYLLABLE; };
181	other					=> { found_syllable (use_non_cluster); };
182*|;
183
184
185}%%
186
187#define found_syllable(syllable_type) \
188  HB_STMT_START { \
189    if (0) fprintf (stderr, "syllable %u..%u %s\n", (*ts).second.first, (*te).second.first, #syllable_type); \
190    for (unsigned i = (*ts).second.first; i < (*te).second.first; ++i) \
191      info[i].syllable() = (syllable_serial << 4) | syllable_type; \
192    syllable_serial++; \
193    if (syllable_serial == 16) syllable_serial = 1; \
194  } HB_STMT_END
195
196
197template <typename Iter>
198struct machine_index_t :
199  hb_iter_with_fallback_t<machine_index_t<Iter>,
200			  typename Iter::item_t>
201{
202  machine_index_t (const Iter& it) : it (it) {}
203  machine_index_t (const machine_index_t& o) : hb_iter_with_fallback_t<machine_index_t<Iter>,
204								       typename Iter::item_t> (),
205					       it (o.it), is_null (o.is_null) {}
206
207  static constexpr bool is_random_access_iterator = Iter::is_random_access_iterator;
208  static constexpr bool is_sorted_iterator = Iter::is_sorted_iterator;
209
210  typename Iter::item_t __item__ () const { return *it; }
211  typename Iter::item_t __item_at__ (unsigned i) const { return it[i]; }
212  unsigned __len__ () const { return it.len (); }
213  void __next__ () { ++it; }
214  void __forward__ (unsigned n) { it += n; }
215  void __prev__ () { --it; }
216  void __rewind__ (unsigned n) { it -= n; }
217
218  void operator = (unsigned n)
219  {
220    assert (n == 0);
221    is_null = true;
222  }
223  explicit operator bool () { return !is_null; }
224
225  void operator = (const machine_index_t& o)
226  {
227    is_null = o.is_null;
228    unsigned index = (*it).first;
229    unsigned n = (*o.it).first;
230    if (index < n) it += n - index; else if (index > n) it -= index - n;
231  }
232  bool operator == (const machine_index_t& o) const
233  { return is_null ? o.is_null : !o.is_null && (*it).first == (*o.it).first; }
234  bool operator != (const machine_index_t& o) const { return !(*this == o); }
235
236  private:
237  Iter it;
238  bool is_null = false;
239};
240struct
241{
242  template <typename Iter,
243	    hb_requires (hb_is_iterable (Iter))>
244  machine_index_t<hb_iter_type<Iter>>
245  operator () (Iter&& it) const
246  { return machine_index_t<hb_iter_type<Iter>> (hb_iter (it)); }
247}
248HB_FUNCOBJ (machine_index);
249
250
251
252static bool
253not_ccs_default_ignorable (const hb_glyph_info_t &i)
254{ return i.use_category() != USE(CGJ); }
255
256static inline void
257find_syllables_use (hb_buffer_t *buffer)
258{
259  hb_glyph_info_t *info = buffer->info;
260  auto p =
261    + hb_iter (info, buffer->len)
262    | hb_enumerate
263    | hb_filter ([] (const hb_glyph_info_t &i) { return not_ccs_default_ignorable (i); },
264		 hb_second)
265    | hb_filter ([&] (const hb_pair_t<unsigned, const hb_glyph_info_t &> p)
266		 {
267		   if (p.second.use_category() == USE(ZWNJ))
268		     for (unsigned i = p.first + 1; i < buffer->len; ++i)
269		       if (not_ccs_default_ignorable (info[i]))
270			 return !_hb_glyph_info_is_unicode_mark (&info[i]);
271		   return true;
272		 })
273    | hb_enumerate
274    | machine_index
275    ;
276  auto pe = p + p.len ();
277  auto eof = +pe;
278  auto ts = +p;
279  auto te = +p;
280  unsigned int act HB_UNUSED;
281  int cs;
282  %%{
283    write init;
284    getkey (*p).second.second.use_category();
285  }%%
286
287  unsigned int syllable_serial = 1;
288  %%{
289    write exec;
290  }%%
291}
292
293#undef found_syllable
294
295#endif /* HB_OT_SHAPER_USE_MACHINE_HH */
296