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_PRIVATE_HH
28 #define HB_OT_SHAPE_COMPLEX_INDIC_PRIVATE_HH
29
30 #include "hb-private.hh"
31
32
33 #include "hb-ot-shape-complex-private.hh"
34 #include "hb-ot-shape-private.hh" /* XXX Remove */
35
36
37 /* buffer var allocations */
38 #define indic_category() complex_var_u8_0() /* indic_category_t */
39 #define indic_position() complex_var_u8_1() /* indic_position_t */
40
41
42 #define INDIC_TABLE_ELEMENT_TYPE uint16_t
43
44 /* Cateories used in the OpenType spec:
45 * https://docs.microsoft.com/en-us/typography/script-development/devanagari
46 */
47 /* Note: This enum is duplicated in the -machine.rl source file.
48 * Not sure how to avoid duplication. */
49 enum indic_category_t {
50 OT_X = 0,
51 OT_C = 1,
52 OT_V = 2,
53 OT_N = 3,
54 OT_H = 4,
55 OT_ZWNJ = 5,
56 OT_ZWJ = 6,
57 OT_M = 7,
58 OT_SM = 8,
59 /* OT_VD = 9, UNUSED; we use OT_A instead. */
60 OT_A = 10,
61 OT_PLACEHOLDER = 11,
62 OT_DOTTEDCIRCLE = 12,
63 OT_RS = 13, /* Register Shifter, used in Khmer OT spec. */
64 OT_Coeng = 14, /* Khmer-style Virama. */
65 OT_Repha = 15, /* Atomically-encoded logical or visual repha. */
66 OT_Ra = 16,
67 OT_CM = 17, /* Consonant-Medial. */
68 OT_Symbol = 18, /* Avagraha, etc that take marks (SM,A,VD). */
69 OT_CS = 19
70 };
71
72 #define MEDIAL_FLAGS (FLAG (OT_CM))
73
74 /* Note:
75 *
76 * We treat Vowels and placeholders as if they were consonants. This is safe because Vowels
77 * cannot happen in a consonant syllable. The plus side however is, we can call the
78 * consonant syllable logic from the vowel syllable function and get it all right! */
79 #define CONSONANT_FLAGS (FLAG (OT_C) | FLAG (OT_CS) | FLAG (OT_Ra) | MEDIAL_FLAGS | FLAG (OT_V) | FLAG (OT_PLACEHOLDER) | FLAG (OT_DOTTEDCIRCLE))
80 #define JOINER_FLAGS (FLAG (OT_ZWJ) | FLAG (OT_ZWNJ))
81
82
83 /* Visual positions in a syllable from left to right. */
84 enum indic_position_t {
85 POS_START = 0,
86
87 POS_RA_TO_BECOME_REPH = 1,
88 POS_PRE_M = 2,
89 POS_PRE_C = 3,
90
91 POS_BASE_C = 4,
92 POS_AFTER_MAIN = 5,
93
94 POS_ABOVE_C = 6,
95
96 POS_BEFORE_SUB = 7,
97 POS_BELOW_C = 8,
98 POS_AFTER_SUB = 9,
99
100 POS_BEFORE_POST = 10,
101 POS_POST_C = 11,
102 POS_AFTER_POST = 12,
103
104 POS_FINAL_C = 13,
105 POS_SMVD = 14,
106
107 POS_END = 15
108 };
109
110 /* Categories used in IndicSyllabicCategory.txt from UCD. */
111 enum indic_syllabic_category_t {
112 INDIC_SYLLABIC_CATEGORY_OTHER = OT_X,
113
114 INDIC_SYLLABIC_CATEGORY_AVAGRAHA = OT_Symbol,
115 INDIC_SYLLABIC_CATEGORY_BINDU = OT_SM,
116 INDIC_SYLLABIC_CATEGORY_BRAHMI_JOINING_NUMBER = OT_PLACEHOLDER, /* Don't care. */
117 INDIC_SYLLABIC_CATEGORY_CANTILLATION_MARK = OT_A,
118 INDIC_SYLLABIC_CATEGORY_CONSONANT = OT_C,
119 INDIC_SYLLABIC_CATEGORY_CONSONANT_DEAD = OT_C,
120 INDIC_SYLLABIC_CATEGORY_CONSONANT_FINAL = OT_CM,
121 INDIC_SYLLABIC_CATEGORY_CONSONANT_HEAD_LETTER = OT_C,
122 INDIC_SYLLABIC_CATEGORY_CONSONANT_KILLER = OT_M, /* U+17CD only. */
123 INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL = OT_CM,
124 INDIC_SYLLABIC_CATEGORY_CONSONANT_PLACEHOLDER = OT_PLACEHOLDER,
125 INDIC_SYLLABIC_CATEGORY_CONSONANT_PRECEDING_REPHA = OT_Repha,
126 INDIC_SYLLABIC_CATEGORY_CONSONANT_PREFIXED = OT_X, /* Don't care. */
127 INDIC_SYLLABIC_CATEGORY_CONSONANT_SUBJOINED = OT_CM,
128 INDIC_SYLLABIC_CATEGORY_CONSONANT_SUCCEEDING_REPHA = OT_N,
129 INDIC_SYLLABIC_CATEGORY_CONSONANT_WITH_STACKER = OT_CS,
130 INDIC_SYLLABIC_CATEGORY_GEMINATION_MARK = OT_SM, /* https://github.com/harfbuzz/harfbuzz/issues/552 */
131 INDIC_SYLLABIC_CATEGORY_INVISIBLE_STACKER = OT_Coeng,
132 INDIC_SYLLABIC_CATEGORY_JOINER = OT_ZWJ,
133 INDIC_SYLLABIC_CATEGORY_MODIFYING_LETTER = OT_X,
134 INDIC_SYLLABIC_CATEGORY_NON_JOINER = OT_ZWNJ,
135 INDIC_SYLLABIC_CATEGORY_NUKTA = OT_N,
136 INDIC_SYLLABIC_CATEGORY_NUMBER = OT_PLACEHOLDER,
137 INDIC_SYLLABIC_CATEGORY_NUMBER_JOINER = OT_PLACEHOLDER, /* Don't care. */
138 INDIC_SYLLABIC_CATEGORY_PURE_KILLER = OT_M, /* Is like a vowel matra. */
139 INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER = OT_RS,
140 INDIC_SYLLABIC_CATEGORY_SYLLABLE_MODIFIER = OT_SM,
141 INDIC_SYLLABIC_CATEGORY_TONE_LETTER = OT_X,
142 INDIC_SYLLABIC_CATEGORY_TONE_MARK = OT_N,
143 INDIC_SYLLABIC_CATEGORY_VIRAMA = OT_H,
144 INDIC_SYLLABIC_CATEGORY_VISARGA = OT_SM,
145 INDIC_SYLLABIC_CATEGORY_VOWEL = OT_V,
146 INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT = OT_M,
147 INDIC_SYLLABIC_CATEGORY_VOWEL_INDEPENDENT = OT_V
148 };
149
150 /* Categories used in IndicSMatraCategory.txt from UCD */
151 enum indic_matra_category_t {
152 INDIC_MATRA_CATEGORY_NOT_APPLICABLE = POS_END,
153
154 INDIC_MATRA_CATEGORY_LEFT = POS_PRE_C,
155 INDIC_MATRA_CATEGORY_TOP = POS_ABOVE_C,
156 INDIC_MATRA_CATEGORY_BOTTOM = POS_BELOW_C,
157 INDIC_MATRA_CATEGORY_RIGHT = POS_POST_C,
158
159 /* These should resolve to the position of the last part of the split sequence. */
160 INDIC_MATRA_CATEGORY_BOTTOM_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
161 INDIC_MATRA_CATEGORY_LEFT_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
162 INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM = INDIC_MATRA_CATEGORY_BOTTOM,
163 INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
164 INDIC_MATRA_CATEGORY_TOP_AND_LEFT = INDIC_MATRA_CATEGORY_TOP,
165 INDIC_MATRA_CATEGORY_TOP_AND_LEFT_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
166 INDIC_MATRA_CATEGORY_TOP_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
167
168 INDIC_MATRA_CATEGORY_OVERSTRUCK = POS_AFTER_MAIN,
169 INDIC_MATRA_CATEGORY_VISUAL_ORDER_LEFT = POS_PRE_M
170 };
171
172 #define INDIC_COMBINE_CATEGORIES(S,M) \
173 ( \
174 ASSERT_STATIC_EXPR_ZERO (S < 255 && M < 255) + \
175 ( S | \
176 ( \
177 ( \
178 S == INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL || \
179 S == INDIC_SYLLABIC_CATEGORY_GEMINATION_MARK || \
180 S == INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER || \
181 S == INDIC_SYLLABIC_CATEGORY_CONSONANT_SUCCEEDING_REPHA || \
182 S == INDIC_SYLLABIC_CATEGORY_VIRAMA || \
183 S == INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT || \
184 false \
185 ? M : INDIC_MATRA_CATEGORY_NOT_APPLICABLE \
186 ) << 8 \
187 ) \
188 ) \
189 )
190
191 HB_INTERNAL INDIC_TABLE_ELEMENT_TYPE
192 hb_indic_get_categories (hb_codepoint_t u);
193
194
195 static inline bool
196 is_one_of (const hb_glyph_info_t &info, unsigned int flags)
197 {
198 /* If it ligated, all bets are off. */
199 if (_hb_glyph_info_ligated (&info)) return false;
200 return !!(FLAG_UNSAFE (info.indic_category()) & flags);
201 }
202
203 static inline bool
204 is_joiner (const hb_glyph_info_t &info)
205 {
206 return is_one_of (info, JOINER_FLAGS);
207 }
208
209 static inline bool
210 is_consonant (const hb_glyph_info_t &info)
211 {
212 return is_one_of (info, CONSONANT_FLAGS);
213 }
214
215 static inline bool
216 is_halant (const hb_glyph_info_t &info)
217 {
218 return is_one_of (info, FLAG (OT_H));
219 }
220
221 #define IN_HALF_BLOCK(u, Base) (((u) & ~0x7Fu) == (Base))
222
223 #define IS_DEVA(u) (IN_HALF_BLOCK (u, 0x0900u))
224 #define IS_BENG(u) (IN_HALF_BLOCK (u, 0x0980u))
225 #define IS_GURU(u) (IN_HALF_BLOCK (u, 0x0A00u))
226 #define IS_GUJR(u) (IN_HALF_BLOCK (u, 0x0A80u))
227 #define IS_ORYA(u) (IN_HALF_BLOCK (u, 0x0B00u))
228 #define IS_TAML(u) (IN_HALF_BLOCK (u, 0x0B80u))
229 #define IS_TELU(u) (IN_HALF_BLOCK (u, 0x0C00u))
230 #define IS_KNDA(u) (IN_HALF_BLOCK (u, 0x0C80u))
231 #define IS_MLYM(u) (IN_HALF_BLOCK (u, 0x0D00u))
232 #define IS_SINH(u) (IN_HALF_BLOCK (u, 0x0D80u))
233
234
235 #define MATRA_POS_LEFT(u) POS_PRE_M
236 #define MATRA_POS_RIGHT(u) ( \
237 IS_DEVA(u) ? POS_AFTER_SUB : \
238 IS_BENG(u) ? POS_AFTER_POST : \
239 IS_GURU(u) ? POS_AFTER_POST : \
240 IS_GUJR(u) ? POS_AFTER_POST : \
241 IS_ORYA(u) ? POS_AFTER_POST : \
242 IS_TAML(u) ? POS_AFTER_POST : \
243 IS_TELU(u) ? (u <= 0x0C42u ? POS_BEFORE_SUB : POS_AFTER_SUB) : \
244 IS_KNDA(u) ? (u < 0x0CC3u || u > 0xCD6u ? POS_BEFORE_SUB : POS_AFTER_SUB) : \
245 IS_MLYM(u) ? POS_AFTER_POST : \
246 IS_SINH(u) ? POS_AFTER_SUB : \
247 /*default*/ POS_AFTER_SUB \
248 )
249 #define MATRA_POS_TOP(u) ( /* BENG and MLYM don't have top matras. */ \
250 IS_DEVA(u) ? POS_AFTER_SUB : \
251 IS_GURU(u) ? POS_AFTER_POST : /* Deviate from spec */ \
252 IS_GUJR(u) ? POS_AFTER_SUB : \
253 IS_ORYA(u) ? POS_AFTER_MAIN : \
254 IS_TAML(u) ? POS_AFTER_SUB : \
255 IS_TELU(u) ? POS_BEFORE_SUB : \
256 IS_KNDA(u) ? POS_BEFORE_SUB : \
257 IS_SINH(u) ? POS_AFTER_SUB : \
258 /*default*/ POS_AFTER_SUB \
259 )
260 #define MATRA_POS_BOTTOM(u) ( \
261 IS_DEVA(u) ? POS_AFTER_SUB : \
262 IS_BENG(u) ? POS_AFTER_SUB : \
263 IS_GURU(u) ? POS_AFTER_POST : \
264 IS_GUJR(u) ? POS_AFTER_POST : \
265 IS_ORYA(u) ? POS_AFTER_SUB : \
266 IS_TAML(u) ? POS_AFTER_POST : \
267 IS_TELU(u) ? POS_BEFORE_SUB : \
268 IS_KNDA(u) ? POS_BEFORE_SUB : \
269 IS_MLYM(u) ? POS_AFTER_POST : \
270 IS_SINH(u) ? POS_AFTER_SUB : \
271 /*default*/ POS_AFTER_SUB \
272 )
273
274 static inline indic_position_t
275 matra_position_indic (hb_codepoint_t u, indic_position_t side)
276 {
277 switch ((int) side)
278 {
279 case POS_PRE_C: return MATRA_POS_LEFT (u);
280 case POS_POST_C: return MATRA_POS_RIGHT (u);
281 case POS_ABOVE_C: return MATRA_POS_TOP (u);
282 case POS_BELOW_C: return MATRA_POS_BOTTOM (u);
283 };
284 return side;
285 }
286
287 /* XXX
288 * This is a hack for now. We should move this data into the main Indic table.
289 * Or completely remove it and just check in the tables.
290 */
291 static const hb_codepoint_t ra_chars[] = {
292 0x0930u, /* Devanagari */
293 0x09B0u, /* Bengali */
294 0x09F0u, /* Bengali */
295 0x0A30u, /* Gurmukhi */ /* No Reph */
296 0x0AB0u, /* Gujarati */
297 0x0B30u, /* Oriya */
298 0x0BB0u, /* Tamil */ /* No Reph */
299 0x0C30u, /* Telugu */ /* Reph formed only with ZWJ */
300 0x0CB0u, /* Kannada */
301 0x0D30u, /* Malayalam */ /* No Reph, Logical Repha */
302
303 0x0DBBu, /* Sinhala */ /* Reph formed only with ZWJ */
304 };
305
306 static inline bool
307 is_ra (hb_codepoint_t u)
308 {
309 for (unsigned int i = 0; i < ARRAY_LENGTH (ra_chars); i++)
310 if (u == ra_chars[i])
311 return true;
312 return false;
313 }
314
315 static inline void
316 set_indic_properties (hb_glyph_info_t &info)
317 {
318 hb_codepoint_t u = info.codepoint;
319 unsigned int type = hb_indic_get_categories (u);
320 indic_category_t cat = (indic_category_t) (type & 0x7Fu);
321 indic_position_t pos = (indic_position_t) (type >> 8);
322
323
324 /*
325 * Re-assign category
326 */
327
328 /* The following act more like the Bindus. */
329 if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x0953u, 0x0954u)))
330 cat = OT_SM;
331 /* The following act like consonants. */
332 else if (unlikely (hb_in_ranges<hb_codepoint_t> (u, 0x0A72u, 0x0A73u,
333 0x1CF5u, 0x1CF6u)))
334 cat = OT_C;
335 /* TODO: The following should only be allowed after a Visarga.
336 * For now, just treat them like regular tone marks. */
337 else if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x1CE2u, 0x1CE8u)))
338 cat = OT_A;
339 /* TODO: The following should only be allowed after some of
340 * the nasalization marks, maybe only for U+1CE9..U+1CF1.
341 * For now, just treat them like tone marks. */
342 else if (unlikely (u == 0x1CEDu))
343 cat = OT_A;
344 /* The following take marks in standalone clusters, similar to Avagraha. */
345 else if (unlikely (hb_in_ranges<hb_codepoint_t> (u, 0xA8F2u, 0xA8F7u,
346 0x1CE9u, 0x1CECu,
347 0x1CEEu, 0x1CF1u)))
348 {
349 cat = OT_Symbol;
350 static_assert (((int) INDIC_SYLLABIC_CATEGORY_AVAGRAHA == OT_Symbol), "");
351 }
352 else if (unlikely (u == 0x0A51u))
353 {
354 /* https://github.com/harfbuzz/harfbuzz/issues/524 */
355 cat = OT_M;
356 pos = POS_BELOW_C;
357 }
358
359 /* According to ScriptExtensions.txt, these Grantha marks may also be used in Tamil,
360 * so the Indic shaper needs to know their categories. */
361 else if (unlikely (u == 0x11301u || u == 0x11303u)) cat = OT_SM;
362 else if (unlikely (u == 0x1133cu)) cat = OT_N;
363
364 else if (unlikely (u == 0x0AFBu)) cat = OT_N; /* https://github.com/harfbuzz/harfbuzz/issues/552 */
365
366 else if (unlikely (u == 0x0980u)) cat = OT_PLACEHOLDER; /* https://github.com/harfbuzz/harfbuzz/issues/538 */
367 else if (unlikely (u == 0x0C80u)) cat = OT_PLACEHOLDER; /* https://github.com/harfbuzz/harfbuzz/pull/623 */
368 else if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x2010u, 0x2011u)))
369 cat = OT_PLACEHOLDER;
370 else if (unlikely (u == 0x25CCu)) cat = OT_DOTTEDCIRCLE;
371
372
373 /*
374 * Re-assign position.
375 */
376
377 if ((FLAG_UNSAFE (cat) & CONSONANT_FLAGS))
378 {
379 pos = POS_BASE_C;
380 if (is_ra (u))
381 cat = OT_Ra;
382 }
383 else if (cat == OT_M)
384 {
385 pos = matra_position_indic (u, pos);
386 }
387 else if ((FLAG_UNSAFE (cat) & (FLAG (OT_SM) /* | FLAG (OT_VD) */ | FLAG (OT_A) | FLAG (OT_Symbol))))
388 {
389 pos = POS_SMVD;
390 }
391
392 if (unlikely (u == 0x0B01u)) pos = POS_BEFORE_SUB; /* Oriya Bindu is BeforeSub in the spec. */
393
394
395
396 info.indic_category() = cat;
397 info.indic_position() = pos;
398 }
399
400
401 #endif /* HB_OT_SHAPE_COMPLEX_INDIC_PRIVATE_HH */