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.hh"
33
34
35 /* buffer var allocations */
36 #define indic_category() complex_var_u8_0() /* indic_category_t */
37 #define indic_position() complex_var_u8_1() /* indic_position_t */
38
39
40 #define INDIC_TABLE_ELEMENT_TYPE uint16_t
41
42 /* Cateories used in the OpenType spec:
43 * https://docs.microsoft.com/en-us/typography/script-development/devanagari
44 */
45 /* Note: This enum is duplicated in the -machine.rl source file.
46 * Not sure how to avoid duplication. */
47 enum indic_category_t {
48 OT_X = 0,
49 OT_C = 1,
50 OT_V = 2,
51 OT_N = 3,
52 OT_H = 4,
53 OT_ZWNJ = 5,
54 OT_ZWJ = 6,
55 OT_M = 7,
56 OT_SM = 8,
57 /* OT_VD = 9, UNUSED; we use OT_A instead. */
58 OT_A = 10,
59 OT_PLACEHOLDER = 11,
60 OT_DOTTEDCIRCLE = 12,
61 OT_RS = 13, /* Register Shifter, used in Khmer OT spec. */
62 OT_Coeng = 14, /* Khmer-style Virama. */
63 OT_Repha = 15, /* Atomically-encoded logical or visual repha. */
64 OT_Ra = 16,
65 OT_CM = 17, /* Consonant-Medial; Unused by Indic shaper. */
66 OT_Symbol = 18, /* Avagraha, etc that take marks (SM,A,VD). */
67 OT_CS = 19
68 };
69
70 /* Note:
71 *
72 * We treat Vowels and placeholders as if they were consonants. This is safe because Vowels
73 * cannot happen in a consonant syllable. The plus side however is, we can call the
74 * consonant syllable logic from the vowel syllable function and get it all right! */
75 #define CONSONANT_FLAGS (FLAG (OT_C) | FLAG (OT_CS) | FLAG (OT_Ra) | FLAG (OT_V) | FLAG (OT_PLACEHOLDER) | FLAG (OT_DOTTEDCIRCLE))
76 #define JOINER_FLAGS (FLAG (OT_ZWJ) | FLAG (OT_ZWNJ))
77
78
79 /* Visual positions in a syllable from left to right. */
80 enum indic_position_t {
81 POS_START = 0,
82
83 POS_RA_TO_BECOME_REPH = 1,
84 POS_PRE_M = 2,
85 POS_PRE_C = 3,
86
87 POS_BASE_C = 4,
88 POS_AFTER_MAIN = 5,
89
90 POS_ABOVE_C = 6,
91
92 POS_BEFORE_SUB = 7,
93 POS_BELOW_C = 8,
94 POS_AFTER_SUB = 9,
95
96 POS_BEFORE_POST = 10,
97 POS_POST_C = 11,
98 POS_AFTER_POST = 12,
99
100 POS_FINAL_C = 13,
101 POS_SMVD = 14,
102
103 POS_END = 15
104 };
105
106 /* Categories used in IndicSyllabicCategory.txt from UCD. */
107 enum indic_syllabic_category_t {
108 INDIC_SYLLABIC_CATEGORY_OTHER = OT_X,
109
110 INDIC_SYLLABIC_CATEGORY_AVAGRAHA = OT_Symbol,
111 INDIC_SYLLABIC_CATEGORY_BINDU = OT_SM,
112 INDIC_SYLLABIC_CATEGORY_BRAHMI_JOINING_NUMBER = OT_PLACEHOLDER, /* Don't care. */
113 INDIC_SYLLABIC_CATEGORY_CANTILLATION_MARK = OT_A,
114 INDIC_SYLLABIC_CATEGORY_CONSONANT = OT_C,
115 INDIC_SYLLABIC_CATEGORY_CONSONANT_DEAD = OT_C,
116 INDIC_SYLLABIC_CATEGORY_CONSONANT_FINAL = OT_CM,
117 INDIC_SYLLABIC_CATEGORY_CONSONANT_HEAD_LETTER = OT_C,
118 INDIC_SYLLABIC_CATEGORY_CONSONANT_KILLER = OT_M, /* U+17CD only. */
119 INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL = OT_CM,
120 INDIC_SYLLABIC_CATEGORY_CONSONANT_PLACEHOLDER = OT_PLACEHOLDER,
121 INDIC_SYLLABIC_CATEGORY_CONSONANT_PRECEDING_REPHA = OT_Repha,
122 INDIC_SYLLABIC_CATEGORY_CONSONANT_PREFIXED = OT_X, /* Don't care. */
123 INDIC_SYLLABIC_CATEGORY_CONSONANT_SUBJOINED = OT_CM,
124 INDIC_SYLLABIC_CATEGORY_CONSONANT_SUCCEEDING_REPHA = OT_CM,
125 INDIC_SYLLABIC_CATEGORY_CONSONANT_WITH_STACKER = OT_CS,
126 INDIC_SYLLABIC_CATEGORY_GEMINATION_MARK = OT_SM, /* https://github.com/harfbuzz/harfbuzz/issues/552 */
127 INDIC_SYLLABIC_CATEGORY_INVISIBLE_STACKER = OT_Coeng,
128 INDIC_SYLLABIC_CATEGORY_JOINER = OT_ZWJ,
129 INDIC_SYLLABIC_CATEGORY_MODIFYING_LETTER = OT_X,
130 INDIC_SYLLABIC_CATEGORY_NON_JOINER = OT_ZWNJ,
131 INDIC_SYLLABIC_CATEGORY_NUKTA = OT_N,
132 INDIC_SYLLABIC_CATEGORY_NUMBER = OT_PLACEHOLDER,
133 INDIC_SYLLABIC_CATEGORY_NUMBER_JOINER = OT_PLACEHOLDER, /* Don't care. */
134 INDIC_SYLLABIC_CATEGORY_PURE_KILLER = OT_M, /* Is like a vowel matra. */
135 INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER = OT_RS,
136 INDIC_SYLLABIC_CATEGORY_SYLLABLE_MODIFIER = OT_SM,
137 INDIC_SYLLABIC_CATEGORY_TONE_LETTER = OT_X,
138 INDIC_SYLLABIC_CATEGORY_TONE_MARK = OT_N,
139 INDIC_SYLLABIC_CATEGORY_VIRAMA = OT_H,
140 INDIC_SYLLABIC_CATEGORY_VISARGA = OT_SM,
141 INDIC_SYLLABIC_CATEGORY_VOWEL = OT_V,
142 INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT = OT_M,
143 INDIC_SYLLABIC_CATEGORY_VOWEL_INDEPENDENT = OT_V
144 };
145
146 /* Categories used in IndicSMatraCategory.txt from UCD */
147 enum indic_matra_category_t {
148 INDIC_MATRA_CATEGORY_NOT_APPLICABLE = POS_END,
149
150 INDIC_MATRA_CATEGORY_LEFT = POS_PRE_C,
151 INDIC_MATRA_CATEGORY_TOP = POS_ABOVE_C,
152 INDIC_MATRA_CATEGORY_BOTTOM = POS_BELOW_C,
153 INDIC_MATRA_CATEGORY_RIGHT = POS_POST_C,
154
155 /* These should resolve to the position of the last part of the split sequence. */
156 INDIC_MATRA_CATEGORY_BOTTOM_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
157 INDIC_MATRA_CATEGORY_LEFT_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
158 INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM = INDIC_MATRA_CATEGORY_BOTTOM,
159 INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
160 INDIC_MATRA_CATEGORY_TOP_AND_LEFT = INDIC_MATRA_CATEGORY_TOP,
161 INDIC_MATRA_CATEGORY_TOP_AND_LEFT_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
162 INDIC_MATRA_CATEGORY_TOP_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
163
164 INDIC_MATRA_CATEGORY_OVERSTRUCK = POS_AFTER_MAIN,
165 INDIC_MATRA_CATEGORY_VISUAL_ORDER_LEFT = POS_PRE_M
166 };
167
168 #define INDIC_COMBINE_CATEGORIES(S,M) \
169 ( \
170 ASSERT_STATIC_EXPR_ZERO (S < 255 && M < 255) + \
171 ( S | \
172 ( \
173 ( \
174 S == INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL || \
175 S == INDIC_SYLLABIC_CATEGORY_GEMINATION_MARK || \
176 S == INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER || \
177 S == INDIC_SYLLABIC_CATEGORY_CONSONANT_SUCCEEDING_REPHA || \
178 S == INDIC_SYLLABIC_CATEGORY_VIRAMA || \
179 S == INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT || \
180 false \
181 ? M : INDIC_MATRA_CATEGORY_NOT_APPLICABLE \
182 ) << 8 \
183 ) \
184 ) \
185 )
186
187 HB_INTERNAL INDIC_TABLE_ELEMENT_TYPE
188 hb_indic_get_categories (hb_codepoint_t u);
189
190
191 static inline bool
192 is_one_of (const hb_glyph_info_t &info, unsigned int flags)
193 {
194 /* If it ligated, all bets are off. */
195 if (_hb_glyph_info_ligated (&info)) return false;
196 return !!(FLAG_UNSAFE (info.indic_category()) & flags);
197 }
198
199 static inline bool
200 is_joiner (const hb_glyph_info_t &info)
201 {
202 return is_one_of (info, JOINER_FLAGS);
203 }
204
205 static inline bool
206 is_consonant (const hb_glyph_info_t &info)
207 {
208 return is_one_of (info, CONSONANT_FLAGS);
209 }
210
211 static inline bool
212 is_halant (const hb_glyph_info_t &info)
213 {
214 return is_one_of (info, FLAG (OT_H));
215 }
216
217 #define IN_HALF_BLOCK(u, Base) (((u) & ~0x7Fu) == (Base))
218
219 #define IS_DEVA(u) (IN_HALF_BLOCK (u, 0x0900u))
220 #define IS_BENG(u) (IN_HALF_BLOCK (u, 0x0980u))
221 #define IS_GURU(u) (IN_HALF_BLOCK (u, 0x0A00u))
222 #define IS_GUJR(u) (IN_HALF_BLOCK (u, 0x0A80u))
223 #define IS_ORYA(u) (IN_HALF_BLOCK (u, 0x0B00u))
224 #define IS_TAML(u) (IN_HALF_BLOCK (u, 0x0B80u))
225 #define IS_TELU(u) (IN_HALF_BLOCK (u, 0x0C00u))
226 #define IS_KNDA(u) (IN_HALF_BLOCK (u, 0x0C80u))
227 #define IS_MLYM(u) (IN_HALF_BLOCK (u, 0x0D00u))
228 #define IS_SINH(u) (IN_HALF_BLOCK (u, 0x0D80u))
229
230
231 #define MATRA_POS_LEFT(u) POS_PRE_M
232 #define MATRA_POS_RIGHT(u) ( \
233 IS_DEVA(u) ? POS_AFTER_SUB : \
234 IS_BENG(u) ? POS_AFTER_POST : \
235 IS_GURU(u) ? POS_AFTER_POST : \
236 IS_GUJR(u) ? POS_AFTER_POST : \
237 IS_ORYA(u) ? POS_AFTER_POST : \
238 IS_TAML(u) ? POS_AFTER_POST : \
239 IS_TELU(u) ? (u <= 0x0C42u ? POS_BEFORE_SUB : POS_AFTER_SUB) : \
240 IS_KNDA(u) ? (u < 0x0CC3u || u > 0xCD6u ? POS_BEFORE_SUB : POS_AFTER_SUB) : \
241 IS_MLYM(u) ? POS_AFTER_POST : \
242 IS_SINH(u) ? POS_AFTER_SUB : \
243 /*default*/ POS_AFTER_SUB \
244 )
245 #define MATRA_POS_TOP(u) ( /* BENG and MLYM don't have top matras. */ \
246 IS_DEVA(u) ? POS_AFTER_SUB : \
247 IS_GURU(u) ? POS_AFTER_POST : /* Deviate from spec */ \
248 IS_GUJR(u) ? POS_AFTER_SUB : \
249 IS_ORYA(u) ? POS_AFTER_MAIN : \
250 IS_TAML(u) ? POS_AFTER_SUB : \
251 IS_TELU(u) ? POS_BEFORE_SUB : \
252 IS_KNDA(u) ? POS_BEFORE_SUB : \
253 IS_SINH(u) ? POS_AFTER_SUB : \
254 /*default*/ POS_AFTER_SUB \
255 )
256 #define MATRA_POS_BOTTOM(u) ( \
257 IS_DEVA(u) ? POS_AFTER_SUB : \
258 IS_BENG(u) ? POS_AFTER_SUB : \
259 IS_GURU(u) ? POS_AFTER_POST : \
260 IS_GUJR(u) ? POS_AFTER_POST : \
261 IS_ORYA(u) ? POS_AFTER_SUB : \
262 IS_TAML(u) ? POS_AFTER_POST : \
263 IS_TELU(u) ? POS_BEFORE_SUB : \
264 IS_KNDA(u) ? POS_BEFORE_SUB : \
265 IS_MLYM(u) ? POS_AFTER_POST : \
266 IS_SINH(u) ? POS_AFTER_SUB : \
267 /*default*/ POS_AFTER_SUB \
268 )
269
270 static inline indic_position_t
271 matra_position_indic (hb_codepoint_t u, indic_position_t side)
272 {
273 switch ((int) side)
274 {
275 case POS_PRE_C: return MATRA_POS_LEFT (u);
276 case POS_POST_C: return MATRA_POS_RIGHT (u);
277 case POS_ABOVE_C: return MATRA_POS_TOP (u);
278 case POS_BELOW_C: return MATRA_POS_BOTTOM (u);
279 };
280 return side;
281 }
282
283 /* XXX
284 * This is a hack for now. We should move this data into the main Indic table.
285 * Or completely remove it and just check in the tables.
286 */
287 static const hb_codepoint_t ra_chars[] = {
288 0x0930u, /* Devanagari */
289 0x09B0u, /* Bengali */
290 0x09F0u, /* Bengali */
291 0x0A30u, /* Gurmukhi */ /* No Reph */
292 0x0AB0u, /* Gujarati */
293 0x0B30u, /* Oriya */
294 0x0BB0u, /* Tamil */ /* No Reph */
295 0x0C30u, /* Telugu */ /* Reph formed only with ZWJ */
296 0x0CB0u, /* Kannada */
297 0x0D30u, /* Malayalam */ /* No Reph, Logical Repha */
298
299 0x0DBBu, /* Sinhala */ /* Reph formed only with ZWJ */
300
301 0x179Au, /* Khmer */
302 };
303
304 static inline bool
305 is_ra (hb_codepoint_t u)
306 {
307 for (unsigned int i = 0; i < ARRAY_LENGTH (ra_chars); i++)
308 if (u == ra_chars[i])
309 return true;
310 return false;
311 }
312
313 static inline void
314 set_indic_properties (hb_glyph_info_t &info)
315 {
316 hb_codepoint_t u = info.codepoint;
317 unsigned int type = hb_indic_get_categories (u);
318 indic_category_t cat = (indic_category_t) (type & 0x7Fu);
319 indic_position_t pos = (indic_position_t) (type >> 8);
320
321
322 /*
323 * Re-assign category
324 */
325
326 /* The following act more like the Bindus. */
327 if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x0953u, 0x0954u)))
328 cat = OT_SM;
329 /* The following act like consonants. */
330 else if (unlikely (hb_in_ranges<hb_codepoint_t> (u, 0x0A72u, 0x0A73u,
331 0x1CF5u, 0x1CF6u)))
332 cat = OT_C;
333 /* TODO: The following should only be allowed after a Visarga.
334 * For now, just treat them like regular tone marks. */
335 else if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x1CE2u, 0x1CE8u)))
336 cat = OT_A;
337 /* TODO: The following should only be allowed after some of
338 * the nasalization marks, maybe only for U+1CE9..U+1CF1.
339 * For now, just treat them like tone marks. */
340 else if (unlikely (u == 0x1CEDu))
341 cat = OT_A;
342 /* The following take marks in standalone clusters, similar to Avagraha. */
343 else if (unlikely (hb_in_ranges<hb_codepoint_t> (u, 0xA8F2u, 0xA8F7u,
344 0x1CE9u, 0x1CECu,
345 0x1CEEu, 0x1CF1u)))
346 {
347 cat = OT_Symbol;
348 static_assert (((int) INDIC_SYLLABIC_CATEGORY_AVAGRAHA == OT_Symbol), "");
349 }
350 else if (unlikely (u == 0x0A51u))
351 {
352 /* https://github.com/harfbuzz/harfbuzz/issues/524 */
353 cat = OT_M;
354 pos = POS_BELOW_C;
355 }
356
357 /* According to ScriptExtensions.txt, these Grantha marks may also be used in Tamil,
358 * so the Indic shaper needs to know their categories. */
359 else if (unlikely (u == 0x11301u || u == 0x11303u)) cat = OT_SM;
360 else if (unlikely (u == 0x1133cu)) cat = OT_N;
361
362 else if (unlikely (u == 0x0AFBu)) cat = OT_N; /* https://github.com/harfbuzz/harfbuzz/issues/552 */
363
364 else if (unlikely (u == 0x0980u)) cat = OT_PLACEHOLDER; /* https://github.com/harfbuzz/harfbuzz/issues/538 */
365 else if (unlikely (u == 0x0C80u)) cat = OT_PLACEHOLDER; /* https://github.com/harfbuzz/harfbuzz/pull/623 */
366 else if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x2010u, 0x2011u)))
367 cat = OT_PLACEHOLDER;
368 else if (unlikely (u == 0x25CCu)) cat = OT_DOTTEDCIRCLE;
369
370
371 /*
372 * Re-assign position.
373 */
374
375 if ((FLAG_UNSAFE (cat) & CONSONANT_FLAGS))
376 {
377 pos = POS_BASE_C;
378 if (is_ra (u))
379 cat = OT_Ra;
380 }
381 else if (cat == OT_M)
382 {
383 pos = matra_position_indic (u, pos);
384 }
385 else if ((FLAG_UNSAFE (cat) & (FLAG (OT_SM) /* | FLAG (OT_VD) */ | FLAG (OT_A) | FLAG (OT_Symbol))))
386 {
387 pos = POS_SMVD;
388 }
389
390 if (unlikely (u == 0x0B01u)) pos = POS_BEFORE_SUB; /* Oriya Bindu is BeforeSub in the spec. */
391
392
393
394 info.indic_category() = cat;
395 info.indic_position() = pos;
396 }
397
398
399 #endif /* HB_OT_SHAPE_COMPLEX_INDIC_HH */