xref: /aosp_15_r20/external/harfbuzz_ng/src/hb-ot-shaper-indic-machine.rl (revision 2d1272b857b1f7575e6e246373e1cb218663db8a)
1/*
2 * Copyright © 2011,2012  Google, Inc.
3 *
4 *  This is part of HarfBuzz, a text shaping library.
5 *
6 * Permission is hereby granted, without written agreement and without
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
11 *
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16 * DAMAGE.
17 *
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23 *
24 * Google Author(s): Behdad Esfahbod
25 */
26
27#ifndef HB_OT_SHAPER_INDIC_MACHINE_HH
28#define HB_OT_SHAPER_INDIC_MACHINE_HH
29
30#include "hb.hh"
31
32#include "hb-ot-layout.hh"
33#include "hb-ot-shaper-indic.hh"
34
35/* buffer var allocations */
36#define indic_category() ot_shaper_var_u8_category() /* indic_category_t */
37#define indic_position() ot_shaper_var_u8_auxiliary() /* indic_position_t */
38
39using indic_category_t = unsigned;
40using indic_position_t = ot_position_t;
41
42#define I_Cat(Cat) indic_syllable_machine_ex_##Cat
43
44enum indic_syllable_type_t {
45  indic_consonant_syllable,
46  indic_vowel_syllable,
47  indic_standalone_cluster,
48  indic_symbol_cluster,
49  indic_broken_cluster,
50  indic_non_indic_cluster,
51};
52
53%%{
54  machine indic_syllable_machine;
55  alphtype unsigned char;
56  write exports;
57  write data;
58}%%
59
60%%{
61
62
63export X    = 0;
64export C    = 1;
65export V    = 2;
66export N    = 3;
67export H    = 4;
68export ZWNJ = 5;
69export ZWJ  = 6;
70export M    = 7;
71export SM   = 8;
72export A    = 9;
73export VD   = 9;
74export PLACEHOLDER = 10;
75export DOTTEDCIRCLE = 11;
76export RS    = 12;
77export MPst  = 13;
78export Repha = 14;
79export Ra    = 15;
80export CM    = 16;
81export Symbol= 17;
82export CS    = 18;
83
84
85c = (C | Ra);			# is_consonant
86n = ((ZWNJ?.RS)? (N.N?)?);	# is_consonant_modifier
87z = ZWJ|ZWNJ;			# is_joiner
88reph = (Ra H | Repha);		# possible reph
89
90cn = c.ZWJ?.n?;
91symbol = Symbol.N?;
92matra_group = z*.(M | SM? MPst).N?.H?;
93syllable_tail = (z?.SM.SM?.ZWNJ?)? (A | VD)*;
94halant_group = (z?.H.(ZWJ.N?)?);
95final_halant_group = halant_group | H.ZWNJ;
96medial_group = CM?;
97halant_or_matra_group = (final_halant_group | matra_group*);
98
99complex_syllable_tail = (halant_group.cn)* medial_group halant_or_matra_group syllable_tail;
100
101consonant_syllable =	(Repha|CS)? cn complex_syllable_tail;
102vowel_syllable =	reph? V.n? (ZWJ | complex_syllable_tail);
103standalone_cluster =	((Repha|CS)? PLACEHOLDER | reph? DOTTEDCIRCLE).n? complex_syllable_tail;
104symbol_cluster =	symbol syllable_tail;
105broken_cluster =	reph? n? complex_syllable_tail;
106other =			any;
107
108main := |*
109	consonant_syllable	=> { found_syllable (indic_consonant_syllable); };
110	vowel_syllable		=> { found_syllable (indic_vowel_syllable); };
111	standalone_cluster	=> { found_syllable (indic_standalone_cluster); };
112	symbol_cluster		=> { found_syllable (indic_symbol_cluster); };
113	broken_cluster		=> { found_syllable (indic_broken_cluster); buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_BROKEN_SYLLABLE; };
114	other			=> { found_syllable (indic_non_indic_cluster); };
115*|;
116
117
118}%%
119
120#define found_syllable(syllable_type) \
121  HB_STMT_START { \
122    if (0) fprintf (stderr, "syllable %u..%u %s\n", ts, te, #syllable_type); \
123    for (unsigned int i = ts; i < te; i++) \
124      info[i].syllable() = (syllable_serial << 4) | syllable_type; \
125    syllable_serial++; \
126    if (syllable_serial == 16) syllable_serial = 1; \
127  } HB_STMT_END
128
129inline void
130find_syllables_indic (hb_buffer_t *buffer)
131{
132  unsigned int p, pe, eof, ts, te, act;
133  int cs;
134  hb_glyph_info_t *info = buffer->info;
135  %%{
136    write init;
137    getkey info[p].indic_category();
138  }%%
139
140  p = 0;
141  pe = eof = buffer->len;
142
143  unsigned int syllable_serial = 1;
144  %%{
145    write exec;
146  }%%
147}
148
149#undef found_syllable
150
151#endif /* HB_OT_SHAPER_INDIC_MACHINE_HH */
152