1 /*
2 * Copyright © 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_SHAPE_COMPLEX_INDIC_HH
28 #define HB_OT_SHAPE_COMPLEX_INDIC_HH
29
30 #include "hb.hh"
31
32 #include "hb-ot-shape-complex-syllabic.hh"
33
34
35 /* buffer var allocations */
36 #define indic_category() complex_var_u8_category() /* indic_category_t */
37 #define indic_position() complex_var_u8_auxiliary() /* indic_position_t */
38
39
40 /* Cateories used in the OpenType spec:
41 * https://docs.microsoft.com/en-us/typography/script-development/devanagari
42 */
43 /* Note: This enum is duplicated in the -machine.rl source file.
44 * Not sure how to avoid duplication. */
45 enum indic_category_t {
46 OT_X = 0,
47 OT_C = 1,
48 OT_V = 2,
49 OT_N = 3,
50 OT_H = 4,
51 OT_ZWNJ = 5,
52 OT_ZWJ = 6,
53 OT_M = 7,
54 OT_SM = 8,
55 /* OT_VD = 9, UNUSED; we use OT_A instead. */
56 OT_A = 10,
57 OT_PLACEHOLDER = 11,
58 OT_DOTTEDCIRCLE = 12,
59 OT_RS = 13, /* Register Shifter, used in Khmer OT spec. */
60 OT_Coeng = 14, /* Khmer-style Virama. */
61 OT_Repha = 15, /* Atomically-encoded logical or visual repha. */
62 OT_Ra = 16,
63 OT_CM = 17, /* Consonant-Medial. */
64 OT_Symbol = 18, /* Avagraha, etc that take marks (SM,A,VD). */
65 OT_CS = 19,
66
67 /* The following are used by Khmer & Myanmar shapers. Defined
68 * here for them to share. */
69 OT_VAbv = 26,
70 OT_VBlw = 27,
71 OT_VPre = 28,
72 OT_VPst = 29,
73 };
74
75 #define MEDIAL_FLAGS (FLAG (OT_CM))
76
77 /* Note:
78 *
79 * We treat Vowels and placeholders as if they were consonants. This is safe because Vowels
80 * cannot happen in a consonant syllable. The plus side however is, we can call the
81 * consonant syllable logic from the vowel syllable function and get it all right! */
82 #define CONSONANT_FLAGS (FLAG (OT_C) | FLAG (OT_CS) | FLAG (OT_Ra) | MEDIAL_FLAGS | FLAG (OT_V) | FLAG (OT_PLACEHOLDER) | FLAG (OT_DOTTEDCIRCLE))
83 #define JOINER_FLAGS (FLAG (OT_ZWJ) | FLAG (OT_ZWNJ))
84
85
86 /* Visual positions in a syllable from left to right. */
87 enum indic_position_t {
88 POS_START = 0,
89
90 POS_RA_TO_BECOME_REPH = 1,
91 POS_PRE_M = 2,
92 POS_PRE_C = 3,
93
94 POS_BASE_C = 4,
95 POS_AFTER_MAIN = 5,
96
97 POS_ABOVE_C = 6,
98
99 POS_BEFORE_SUB = 7,
100 POS_BELOW_C = 8,
101 POS_AFTER_SUB = 9,
102
103 POS_BEFORE_POST = 10,
104 POS_POST_C = 11,
105 POS_AFTER_POST = 12,
106
107 POS_FINAL_C = 13,
108 POS_SMVD = 14,
109
110 POS_END = 15
111 };
112
113 /* Categories used in IndicSyllabicCategory.txt from UCD. */
114 enum indic_syllabic_category_t {
115 INDIC_SYLLABIC_CATEGORY_OTHER = OT_X,
116
117 INDIC_SYLLABIC_CATEGORY_AVAGRAHA = OT_Symbol,
118 INDIC_SYLLABIC_CATEGORY_BINDU = OT_SM,
119 INDIC_SYLLABIC_CATEGORY_BRAHMI_JOINING_NUMBER = OT_PLACEHOLDER, /* Don't care. */
120 INDIC_SYLLABIC_CATEGORY_CANTILLATION_MARK = OT_A,
121 INDIC_SYLLABIC_CATEGORY_CONSONANT = OT_C,
122 INDIC_SYLLABIC_CATEGORY_CONSONANT_DEAD = OT_C,
123 INDIC_SYLLABIC_CATEGORY_CONSONANT_FINAL = OT_CM,
124 INDIC_SYLLABIC_CATEGORY_CONSONANT_HEAD_LETTER = OT_C,
125 INDIC_SYLLABIC_CATEGORY_CONSONANT_KILLER = OT_M, /* U+17CD only. */
126 INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL = OT_CM,
127 INDIC_SYLLABIC_CATEGORY_CONSONANT_PLACEHOLDER = OT_PLACEHOLDER,
128 INDIC_SYLLABIC_CATEGORY_CONSONANT_PRECEDING_REPHA = OT_Repha,
129 INDIC_SYLLABIC_CATEGORY_CONSONANT_PREFIXED = OT_X, /* Don't care. */
130 INDIC_SYLLABIC_CATEGORY_CONSONANT_SUBJOINED = OT_CM,
131 INDIC_SYLLABIC_CATEGORY_CONSONANT_SUCCEEDING_REPHA = OT_CM,
132 INDIC_SYLLABIC_CATEGORY_CONSONANT_WITH_STACKER = OT_CS,
133 INDIC_SYLLABIC_CATEGORY_GEMINATION_MARK = OT_SM, /* https://github.com/harfbuzz/harfbuzz/issues/552 */
134 INDIC_SYLLABIC_CATEGORY_INVISIBLE_STACKER = OT_Coeng,
135 INDIC_SYLLABIC_CATEGORY_JOINER = OT_ZWJ,
136 INDIC_SYLLABIC_CATEGORY_MODIFYING_LETTER = OT_X,
137 INDIC_SYLLABIC_CATEGORY_NON_JOINER = OT_ZWNJ,
138 INDIC_SYLLABIC_CATEGORY_NUKTA = OT_N,
139 INDIC_SYLLABIC_CATEGORY_NUMBER = OT_PLACEHOLDER,
140 INDIC_SYLLABIC_CATEGORY_NUMBER_JOINER = OT_PLACEHOLDER, /* Don't care. */
141 INDIC_SYLLABIC_CATEGORY_PURE_KILLER = OT_M, /* Is like a vowel matra. */
142 INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER = OT_RS,
143 INDIC_SYLLABIC_CATEGORY_SYLLABLE_MODIFIER = OT_SM,
144 INDIC_SYLLABIC_CATEGORY_TONE_LETTER = OT_X,
145 INDIC_SYLLABIC_CATEGORY_TONE_MARK = OT_N,
146 INDIC_SYLLABIC_CATEGORY_VIRAMA = OT_H,
147 INDIC_SYLLABIC_CATEGORY_VISARGA = OT_SM,
148 INDIC_SYLLABIC_CATEGORY_VOWEL = OT_V,
149 INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT = OT_M,
150 INDIC_SYLLABIC_CATEGORY_VOWEL_INDEPENDENT = OT_V
151 };
152
153 /* Categories used in IndicSMatraCategory.txt from UCD */
154 enum indic_matra_category_t {
155 INDIC_MATRA_CATEGORY_NOT_APPLICABLE = POS_END,
156
157 INDIC_MATRA_CATEGORY_LEFT = POS_PRE_C,
158 INDIC_MATRA_CATEGORY_TOP = POS_ABOVE_C,
159 INDIC_MATRA_CATEGORY_BOTTOM = POS_BELOW_C,
160 INDIC_MATRA_CATEGORY_RIGHT = POS_POST_C,
161
162 /* These should resolve to the position of the last part of the split sequence. */
163 INDIC_MATRA_CATEGORY_BOTTOM_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
164 INDIC_MATRA_CATEGORY_LEFT_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
165 INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM = INDIC_MATRA_CATEGORY_BOTTOM,
166 INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM_AND_LEFT = INDIC_MATRA_CATEGORY_BOTTOM,
167 INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
168 INDIC_MATRA_CATEGORY_TOP_AND_LEFT = INDIC_MATRA_CATEGORY_TOP,
169 INDIC_MATRA_CATEGORY_TOP_AND_LEFT_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
170 INDIC_MATRA_CATEGORY_TOP_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
171
172 INDIC_MATRA_CATEGORY_OVERSTRUCK = POS_AFTER_MAIN,
173 INDIC_MATRA_CATEGORY_VISUAL_ORDER_LEFT = POS_PRE_M
174 };
175
176 #define INDIC_COMBINE_CATEGORIES(S,M) \
177 ( \
178 static_assert_expr (S < 255 && M < 255) + \
179 ( S | \
180 ( \
181 ( \
182 S == INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL || \
183 S == INDIC_SYLLABIC_CATEGORY_GEMINATION_MARK || \
184 S == INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER || \
185 S == INDIC_SYLLABIC_CATEGORY_CONSONANT_SUCCEEDING_REPHA || \
186 S == INDIC_SYLLABIC_CATEGORY_VIRAMA || \
187 S == INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT || \
188 false \
189 ? M : INDIC_MATRA_CATEGORY_NOT_APPLICABLE \
190 ) << 8 \
191 ) \
192 ) \
193 )
194
195 HB_INTERNAL uint16_t
196 hb_indic_get_categories (hb_codepoint_t u);
197
198
199 static inline bool
is_one_of(const hb_glyph_info_t & info,unsigned int flags)200 is_one_of (const hb_glyph_info_t &info, unsigned int flags)
201 {
202 /* If it ligated, all bets are off. */
203 if (_hb_glyph_info_ligated (&info)) return false;
204 return !!(FLAG_UNSAFE (info.indic_category()) & flags);
205 }
206
207 static inline bool
is_joiner(const hb_glyph_info_t & info)208 is_joiner (const hb_glyph_info_t &info)
209 {
210 return is_one_of (info, JOINER_FLAGS);
211 }
212
213 static inline bool
is_consonant(const hb_glyph_info_t & info)214 is_consonant (const hb_glyph_info_t &info)
215 {
216 return is_one_of (info, CONSONANT_FLAGS);
217 }
218
219 static inline bool
is_halant(const hb_glyph_info_t & info)220 is_halant (const hb_glyph_info_t &info)
221 {
222 return is_one_of (info, FLAG (OT_H));
223 }
224
225 #define IN_HALF_BLOCK(u, Base) (((u) & ~0x7Fu) == (Base))
226
227 #define IS_DEVA(u) (IN_HALF_BLOCK (u, 0x0900u))
228 #define IS_BENG(u) (IN_HALF_BLOCK (u, 0x0980u))
229 #define IS_GURU(u) (IN_HALF_BLOCK (u, 0x0A00u))
230 #define IS_GUJR(u) (IN_HALF_BLOCK (u, 0x0A80u))
231 #define IS_ORYA(u) (IN_HALF_BLOCK (u, 0x0B00u))
232 #define IS_TAML(u) (IN_HALF_BLOCK (u, 0x0B80u))
233 #define IS_TELU(u) (IN_HALF_BLOCK (u, 0x0C00u))
234 #define IS_KNDA(u) (IN_HALF_BLOCK (u, 0x0C80u))
235 #define IS_MLYM(u) (IN_HALF_BLOCK (u, 0x0D00u))
236 #define IS_SINH(u) (IN_HALF_BLOCK (u, 0x0D80u))
237
238
239 #define MATRA_POS_LEFT(u) POS_PRE_M
240 #define MATRA_POS_RIGHT(u) ( \
241 IS_DEVA(u) ? POS_AFTER_SUB : \
242 IS_BENG(u) ? POS_AFTER_POST : \
243 IS_GURU(u) ? POS_AFTER_POST : \
244 IS_GUJR(u) ? POS_AFTER_POST : \
245 IS_ORYA(u) ? POS_AFTER_POST : \
246 IS_TAML(u) ? POS_AFTER_POST : \
247 IS_TELU(u) ? (u <= 0x0C42u ? POS_BEFORE_SUB : POS_AFTER_SUB) : \
248 IS_KNDA(u) ? (u < 0x0CC3u || u > 0xCD6u ? POS_BEFORE_SUB : POS_AFTER_SUB) : \
249 IS_MLYM(u) ? POS_AFTER_POST : \
250 IS_SINH(u) ? POS_AFTER_SUB : \
251 /*default*/ POS_AFTER_SUB \
252 )
253 #define MATRA_POS_TOP(u) ( /* BENG and MLYM don't have top matras. */ \
254 IS_DEVA(u) ? POS_AFTER_SUB : \
255 IS_GURU(u) ? POS_AFTER_POST : /* Deviate from spec */ \
256 IS_GUJR(u) ? POS_AFTER_SUB : \
257 IS_ORYA(u) ? POS_AFTER_MAIN : \
258 IS_TAML(u) ? POS_AFTER_SUB : \
259 IS_TELU(u) ? POS_BEFORE_SUB : \
260 IS_KNDA(u) ? POS_BEFORE_SUB : \
261 IS_SINH(u) ? POS_AFTER_SUB : \
262 /*default*/ POS_AFTER_SUB \
263 )
264 #define MATRA_POS_BOTTOM(u) ( \
265 IS_DEVA(u) ? POS_AFTER_SUB : \
266 IS_BENG(u) ? POS_AFTER_SUB : \
267 IS_GURU(u) ? POS_AFTER_POST : \
268 IS_GUJR(u) ? POS_AFTER_POST : \
269 IS_ORYA(u) ? POS_AFTER_SUB : \
270 IS_TAML(u) ? POS_AFTER_POST : \
271 IS_TELU(u) ? POS_BEFORE_SUB : \
272 IS_KNDA(u) ? POS_BEFORE_SUB : \
273 IS_MLYM(u) ? POS_AFTER_POST : \
274 IS_SINH(u) ? POS_AFTER_SUB : \
275 /*default*/ POS_AFTER_SUB \
276 )
277
278 static inline indic_position_t
matra_position_indic(hb_codepoint_t u,indic_position_t side)279 matra_position_indic (hb_codepoint_t u, indic_position_t side)
280 {
281 switch ((int) side)
282 {
283 case POS_PRE_C: return MATRA_POS_LEFT (u);
284 case POS_POST_C: return MATRA_POS_RIGHT (u);
285 case POS_ABOVE_C: return MATRA_POS_TOP (u);
286 case POS_BELOW_C: return MATRA_POS_BOTTOM (u);
287 }
288 return side;
289 }
290
291 /* XXX
292 * This is a hack for now. We should move this data into the main Indic table.
293 * Or completely remove it and just check in the tables.
294 */
295 static const hb_codepoint_t ra_chars[] = {
296 0x0930u, /* Devanagari */
297 0x09B0u, /* Bengali */
298 0x09F0u, /* Bengali */
299 0x0A30u, /* Gurmukhi */ /* No Reph */
300 0x0AB0u, /* Gujarati */
301 0x0B30u, /* Oriya */
302 0x0BB0u, /* Tamil */ /* No Reph */
303 0x0C30u, /* Telugu */ /* Reph formed only with ZWJ */
304 0x0CB0u, /* Kannada */
305 0x0D30u, /* Malayalam */ /* No Reph, Logical Repha */
306
307 0x0DBBu, /* Sinhala */ /* Reph formed only with ZWJ */
308 };
309
310 static inline bool
is_ra(hb_codepoint_t u)311 is_ra (hb_codepoint_t u)
312 {
313 return hb_array (ra_chars).lfind (u);
314 }
315
316 static inline void
set_indic_properties(hb_glyph_info_t & info)317 set_indic_properties (hb_glyph_info_t &info)
318 {
319 hb_codepoint_t u = info.codepoint;
320 unsigned int type = hb_indic_get_categories (u);
321 indic_category_t cat = (indic_category_t) (type & 0xFFu);
322 indic_position_t pos = (indic_position_t) (type >> 8);
323
324
325 /*
326 * Re-assign category
327 */
328
329 /* The following act more like the Bindus. */
330 if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x0953u, 0x0954u)))
331 cat = OT_SM;
332 /* The following act like consonants. */
333 else if (unlikely (hb_in_ranges<hb_codepoint_t> (u, 0x0A72u, 0x0A73u,
334 0x1CF5u, 0x1CF6u)))
335 cat = OT_C;
336 /* TODO: The following should only be allowed after a Visarga.
337 * For now, just treat them like regular tone marks. */
338 else if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x1CE2u, 0x1CE8u)))
339 cat = OT_A;
340 /* TODO: The following should only be allowed after some of
341 * the nasalization marks, maybe only for U+1CE9..U+1CF1.
342 * For now, just treat them like tone marks. */
343 else if (unlikely (u == 0x1CEDu))
344 cat = OT_A;
345 /* The following take marks in standalone clusters, similar to Avagraha. */
346 else if (unlikely (hb_in_ranges<hb_codepoint_t> (u, 0xA8F2u, 0xA8F7u,
347 0x1CE9u, 0x1CECu,
348 0x1CEEu, 0x1CF1u)))
349 {
350 cat = OT_Symbol;
351 static_assert (((int) INDIC_SYLLABIC_CATEGORY_AVAGRAHA == OT_Symbol), "");
352 }
353 else if (unlikely (u == 0x0A51u))
354 {
355 /* https://github.com/harfbuzz/harfbuzz/issues/524 */
356 cat = OT_M;
357 pos = POS_BELOW_C;
358 }
359
360 /* According to ScriptExtensions.txt, these Grantha marks may also be used in Tamil,
361 * so the Indic shaper needs to know their categories. */
362 else if (unlikely (u == 0x11301u || u == 0x11303u)) cat = OT_SM;
363 else if (unlikely (u == 0x1133Bu || u == 0x1133Cu)) cat = OT_N;
364
365 else if (unlikely (u == 0x0AFBu)) cat = OT_N; /* https://github.com/harfbuzz/harfbuzz/issues/552 */
366 else if (unlikely (u == 0x0B55u)) cat = OT_N; /* https://github.com/harfbuzz/harfbuzz/issues/2849 */
367
368 else if (unlikely (u == 0x0980u)) cat = OT_PLACEHOLDER; /* https://github.com/harfbuzz/harfbuzz/issues/538 */
369 else if (unlikely (u == 0x09FCu)) cat = OT_PLACEHOLDER; /* https://github.com/harfbuzz/harfbuzz/pull/1613 */
370 else if (unlikely (u == 0x0C80u)) cat = OT_PLACEHOLDER; /* https://github.com/harfbuzz/harfbuzz/pull/623 */
371 else if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x2010u, 0x2011u)))
372 cat = OT_PLACEHOLDER;
373 else if (unlikely (u == 0x25CCu)) cat = OT_DOTTEDCIRCLE;
374
375
376 /*
377 * Re-assign position.
378 */
379
380 if ((FLAG_UNSAFE (cat) & CONSONANT_FLAGS))
381 {
382 pos = POS_BASE_C;
383 if (is_ra (u))
384 cat = OT_Ra;
385 }
386 else if (cat == OT_M)
387 {
388 pos = matra_position_indic (u, pos);
389 }
390 else if ((FLAG_UNSAFE (cat) & (FLAG (OT_SM) /* | FLAG (OT_VD) */ | FLAG (OT_A) | FLAG (OT_Symbol))))
391 {
392 pos = POS_SMVD;
393 }
394
395 if (unlikely (u == 0x0B01u)) pos = POS_BEFORE_SUB; /* Oriya Bindu is BeforeSub in the spec. */
396
397
398
399 info.indic_category() = cat;
400 info.indic_position() = pos;
401 }
402
403 struct hb_indic_would_substitute_feature_t
404 {
inithb_indic_would_substitute_feature_t405 void init (const hb_ot_map_t *map, hb_tag_t feature_tag, bool zero_context_)
406 {
407 zero_context = zero_context_;
408 map->get_stage_lookups (0/*GSUB*/,
409 map->get_feature_stage (0/*GSUB*/, feature_tag),
410 &lookups, &count);
411 }
412
would_substitutehb_indic_would_substitute_feature_t413 bool would_substitute (const hb_codepoint_t *glyphs,
414 unsigned int glyphs_count,
415 hb_face_t *face) const
416 {
417 for (unsigned int i = 0; i < count; i++)
418 if (hb_ot_layout_lookup_would_substitute (face, lookups[i].index, glyphs, glyphs_count, zero_context))
419 return true;
420 return false;
421 }
422
423 private:
424 const hb_ot_map_t::lookup_map_t *lookups;
425 unsigned int count;
426 bool zero_context;
427 };
428
429
430 #endif /* HB_OT_SHAPE_COMPLEX_INDIC_HH */
431