1 : /*
2 : * Copyright © 2011 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 : #include "hb-ot-shape-complex-private.hh"
28 :
29 :
30 :
31 : /* buffer var allocations */
32 : #define indic_category() complex_var_persistent_u8_0() /* indic_category_t */
33 : #define indic_position() complex_var_persistent_u8_1() /* indic_matra_category_t */
34 :
35 : #define INDIC_TABLE_ELEMENT_TYPE uint8_t
36 :
37 : /* Cateories used in the OpenType spec:
38 : * https://www.microsoft.com/typography/otfntdev/devanot/shaping.aspx
39 : */
40 : /* Note: This enum is duplicated in the -machine.rl source file.
41 : * Not sure how to avoid duplication. */
42 : enum indic_category_t {
43 : OT_X = 0,
44 : OT_C,
45 : OT_Ra, /* Not explicitly listed in the OT spec, but used in the grammar. */
46 : OT_V,
47 : OT_N,
48 : OT_H,
49 : OT_ZWNJ,
50 : OT_ZWJ,
51 : OT_M,
52 : OT_SM,
53 : OT_VD,
54 : OT_A,
55 : OT_NBSP
56 : };
57 :
58 : /* Visual positions in a syllable from left to right. */
59 : enum indic_position_t {
60 : POS_PRE,
61 : POS_BASE,
62 : POS_ABOVE,
63 : POS_BELOW,
64 : POS_POST
65 : };
66 :
67 : /* Categories used in IndicSyllabicCategory.txt from UCD */
68 : /* The assignments are guesswork */
69 : enum indic_syllabic_category_t {
70 : INDIC_SYLLABIC_CATEGORY_OTHER = OT_X,
71 :
72 : INDIC_SYLLABIC_CATEGORY_AVAGRAHA = OT_X,
73 : INDIC_SYLLABIC_CATEGORY_BINDU = OT_SM,
74 : INDIC_SYLLABIC_CATEGORY_CONSONANT = OT_C,
75 : INDIC_SYLLABIC_CATEGORY_CONSONANT_DEAD = OT_C,
76 : INDIC_SYLLABIC_CATEGORY_CONSONANT_FINAL = OT_C,
77 : INDIC_SYLLABIC_CATEGORY_CONSONANT_HEAD_LETTER = OT_C,
78 : INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL = OT_C,
79 : INDIC_SYLLABIC_CATEGORY_CONSONANT_PLACEHOLDER = OT_NBSP,
80 : INDIC_SYLLABIC_CATEGORY_CONSONANT_SUBJOINED = OT_C,
81 : INDIC_SYLLABIC_CATEGORY_CONSONANT_REPHA = OT_C,
82 : INDIC_SYLLABIC_CATEGORY_MODIFYING_LETTER = OT_X,
83 : INDIC_SYLLABIC_CATEGORY_NUKTA = OT_N,
84 : INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER = OT_X,
85 : INDIC_SYLLABIC_CATEGORY_TONE_LETTER = OT_X,
86 : INDIC_SYLLABIC_CATEGORY_TONE_MARK = OT_X,
87 : INDIC_SYLLABIC_CATEGORY_VIRAMA = OT_H,
88 : INDIC_SYLLABIC_CATEGORY_VISARGA = OT_SM,
89 : INDIC_SYLLABIC_CATEGORY_VOWEL = OT_V,
90 : INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT = OT_M,
91 : INDIC_SYLLABIC_CATEGORY_VOWEL_INDEPENDENT = OT_V
92 : };
93 :
94 : /* Categories used in IndicSMatraCategory.txt from UCD */
95 : enum indic_matra_category_t {
96 : INDIC_MATRA_CATEGORY_NOT_APPLICABLE = POS_BASE,
97 :
98 : INDIC_MATRA_CATEGORY_LEFT = POS_PRE,
99 : INDIC_MATRA_CATEGORY_TOP = POS_ABOVE,
100 : INDIC_MATRA_CATEGORY_BOTTOM = POS_BELOW,
101 : INDIC_MATRA_CATEGORY_RIGHT = POS_POST,
102 :
103 : /* We don't really care much about these since we decompose them
104 : * in the generic pre-shaping layer. They will only be used if
105 : * the font does not cover the decomposition. In which case, we
106 : * define these as aliases to the place we want the split-matra
107 : * glyph to show up. Quite arbitrary. */
108 : INDIC_MATRA_CATEGORY_BOTTOM_AND_RIGHT = INDIC_MATRA_CATEGORY_BOTTOM,
109 : INDIC_MATRA_CATEGORY_LEFT_AND_RIGHT = INDIC_MATRA_CATEGORY_LEFT,
110 : INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM = INDIC_MATRA_CATEGORY_BOTTOM,
111 : INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM_AND_RIGHT = INDIC_MATRA_CATEGORY_BOTTOM,
112 : INDIC_MATRA_CATEGORY_TOP_AND_LEFT = INDIC_MATRA_CATEGORY_LEFT,
113 : INDIC_MATRA_CATEGORY_TOP_AND_LEFT_AND_RIGHT = INDIC_MATRA_CATEGORY_LEFT,
114 : INDIC_MATRA_CATEGORY_TOP_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
115 :
116 : INDIC_MATRA_CATEGORY_INVISIBLE = INDIC_MATRA_CATEGORY_NOT_APPLICABLE,
117 : INDIC_MATRA_CATEGORY_OVERSTRUCK = INDIC_MATRA_CATEGORY_NOT_APPLICABLE,
118 : INDIC_MATRA_CATEGORY_VISUAL_ORDER_LEFT = INDIC_MATRA_CATEGORY_NOT_APPLICABLE
119 : };
120 :
121 : /* Note: We use ASSERT_STATIC_EXPR_ZERO() instead of ASSERT_STATIC_EXPR() and the comma operation
122 : * because gcc fails to optimize the latter and fills the table in at runtime. */
123 : #define INDIC_COMBINE_CATEGORIES(S,M) \
124 : (ASSERT_STATIC_EXPR_ZERO (M == INDIC_MATRA_CATEGORY_NOT_APPLICABLE || (S == INDIC_SYLLABIC_CATEGORY_VIRAMA || S == INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT)) + \
125 : ASSERT_STATIC_EXPR_ZERO (S < 16 && M < 16) + \
126 : ((M << 4) | S))
127 :
128 : #include "hb-ot-shape-complex-indic-table.hh"
129 :
130 : /* XXX
131 : * This is a hack for now. We should:
132 : * 1. Move this data into the main Indic table,
133 : * and/or
134 : * 2. Probe font lookups to determine consonant positions.
135 : */
136 : static const struct consonant_position_t {
137 : hb_codepoint_t u;
138 : indic_position_t position;
139 : } consonant_positions[] = {
140 : {0x0930, POS_BELOW},
141 : {0x09AC, POS_BELOW},
142 : {0x09AF, POS_POST},
143 : {0x09B0, POS_BELOW},
144 : {0x09F0, POS_BELOW},
145 : {0x0A2F, POS_POST},
146 : {0x0A30, POS_BELOW},
147 : {0x0A35, POS_BELOW},
148 : {0x0A39, POS_BELOW},
149 : {0x0AB0, POS_BELOW},
150 : {0x0B24, POS_BELOW},
151 : {0x0B28, POS_BELOW},
152 : {0x0B2C, POS_BELOW},
153 : {0x0B2D, POS_BELOW},
154 : {0x0B2E, POS_BELOW},
155 : {0x0B2F, POS_POST},
156 : {0x0B30, POS_BELOW},
157 : {0x0B32, POS_BELOW},
158 : {0x0B33, POS_BELOW},
159 : {0x0B5F, POS_POST},
160 : {0x0B71, POS_BELOW},
161 : {0x0C15, POS_BELOW},
162 : {0x0C16, POS_BELOW},
163 : {0x0C17, POS_BELOW},
164 : {0x0C18, POS_BELOW},
165 : {0x0C19, POS_BELOW},
166 : {0x0C1A, POS_BELOW},
167 : {0x0C1B, POS_BELOW},
168 : {0x0C1C, POS_BELOW},
169 : {0x0C1D, POS_BELOW},
170 : {0x0C1E, POS_BELOW},
171 : {0x0C1F, POS_BELOW},
172 : {0x0C20, POS_BELOW},
173 : {0x0C21, POS_BELOW},
174 : {0x0C22, POS_BELOW},
175 : {0x0C23, POS_BELOW},
176 : {0x0C24, POS_BELOW},
177 : {0x0C25, POS_BELOW},
178 : {0x0C26, POS_BELOW},
179 : {0x0C27, POS_BELOW},
180 : {0x0C28, POS_BELOW},
181 : {0x0C2A, POS_BELOW},
182 : {0x0C2B, POS_BELOW},
183 : {0x0C2C, POS_BELOW},
184 : {0x0C2D, POS_BELOW},
185 : {0x0C2E, POS_BELOW},
186 : {0x0C2F, POS_BELOW},
187 : {0x0C30, POS_BELOW},
188 : {0x0C32, POS_BELOW},
189 : {0x0C33, POS_BELOW},
190 : {0x0C35, POS_BELOW},
191 : {0x0C36, POS_BELOW},
192 : {0x0C37, POS_BELOW},
193 : {0x0C38, POS_BELOW},
194 : {0x0C39, POS_BELOW},
195 : {0x0C95, POS_BELOW},
196 : {0x0C96, POS_BELOW},
197 : {0x0C97, POS_BELOW},
198 : {0x0C98, POS_BELOW},
199 : {0x0C99, POS_BELOW},
200 : {0x0C9A, POS_BELOW},
201 : {0x0C9B, POS_BELOW},
202 : {0x0C9C, POS_BELOW},
203 : {0x0C9D, POS_BELOW},
204 : {0x0C9E, POS_BELOW},
205 : {0x0C9F, POS_BELOW},
206 : {0x0CA0, POS_BELOW},
207 : {0x0CA1, POS_BELOW},
208 : {0x0CA2, POS_BELOW},
209 : {0x0CA3, POS_BELOW},
210 : {0x0CA4, POS_BELOW},
211 : {0x0CA5, POS_BELOW},
212 : {0x0CA6, POS_BELOW},
213 : {0x0CA7, POS_BELOW},
214 : {0x0CA8, POS_BELOW},
215 : {0x0CAA, POS_BELOW},
216 : {0x0CAB, POS_BELOW},
217 : {0x0CAC, POS_BELOW},
218 : {0x0CAD, POS_BELOW},
219 : {0x0CAE, POS_BELOW},
220 : {0x0CAF, POS_BELOW},
221 : {0x0CB0, POS_BELOW},
222 : {0x0CB2, POS_BELOW},
223 : {0x0CB3, POS_BELOW},
224 : {0x0CB5, POS_BELOW},
225 : {0x0CB6, POS_BELOW},
226 : {0x0CB7, POS_BELOW},
227 : {0x0CB8, POS_BELOW},
228 : {0x0CB9, POS_BELOW},
229 : {0x0CDE, POS_BELOW},
230 : {0x0D2F, POS_POST},
231 : {0x0D30, POS_POST},
232 : {0x0D32, POS_BELOW},
233 : {0x0D35, POS_POST},
234 : };
235 :
236 : /* XXX
237 : * This is a hack for now. We should move this data into the main Indic table.
238 : */
239 : static const hb_codepoint_t ra_chars[] = {
240 : 0x0930, /* Devanagari */
241 : 0x09B0, /* Bengali */
242 : 0x09F0, /* Bengali */
243 : //0x09F1, /* Bengali */
244 : //0x0A30, /* Gurmukhi */
245 : 0x0AB0, /* Gujarati */
246 : 0x0B30, /* Oriya */
247 : //0x0BB0, /* Tamil */
248 : //0x0C30, /* Telugu */
249 : 0x0CB0, /* Kannada */
250 : //0x0D30, /* Malayalam */
251 : };
252 :
253 : static int
254 0 : compare_codepoint (const void *pa, const void *pb)
255 : {
256 0 : hb_codepoint_t a = * (hb_codepoint_t *) pa;
257 0 : hb_codepoint_t b = * (hb_codepoint_t *) pb;
258 :
259 0 : return a < b ? -1 : a == b ? 0 : +1;
260 : }
261 :
262 : static indic_position_t
263 0 : consonant_position (hb_codepoint_t u)
264 : {
265 : consonant_position_t *record;
266 :
267 : record = (consonant_position_t *) bsearch (&u, consonant_positions,
268 : ARRAY_LENGTH (consonant_positions),
269 : sizeof (consonant_positions[0]),
270 0 : compare_codepoint);
271 :
272 0 : return record ? record->position : POS_BASE;
273 : }
274 :
275 : static bool
276 0 : is_ra (hb_codepoint_t u)
277 : {
278 : return !!bsearch (&u, ra_chars,
279 : ARRAY_LENGTH (ra_chars),
280 : sizeof (ra_chars[0]),
281 0 : compare_codepoint);
282 : }
283 :
284 : static bool
285 0 : is_joiner (const hb_glyph_info_t &info)
286 : {
287 0 : return !!(FLAG (info.indic_category()) & (FLAG (OT_ZWJ) | FLAG (OT_ZWNJ)));
288 : }
289 :
290 : static bool
291 0 : is_consonant (const hb_glyph_info_t &info)
292 : {
293 0 : return !!(FLAG (info.indic_category()) & (FLAG (OT_C) | FLAG (OT_Ra)));
294 : }
295 :
296 : static const struct {
297 : hb_tag_t tag;
298 : hb_bool_t is_global;
299 : } indic_basic_features[] =
300 : {
301 : {HB_TAG('n','u','k','t'), true},
302 : {HB_TAG('a','k','h','n'), false},
303 : {HB_TAG('r','p','h','f'), false},
304 : {HB_TAG('r','k','r','f'), false},
305 : {HB_TAG('p','r','e','f'), false},
306 : {HB_TAG('b','l','w','f'), false},
307 : {HB_TAG('h','a','l','f'), false},
308 : {HB_TAG('v','a','t','u'), true},
309 : {HB_TAG('p','s','t','f'), false},
310 : {HB_TAG('c','j','c','t'), false},
311 : };
312 :
313 : /* Same order as the indic_basic_features array */
314 : enum {
315 : _NUKT,
316 : AKHN,
317 : RPHF,
318 : RKRF,
319 : PREF,
320 : BLWF,
321 : HALF,
322 : _VATU,
323 : PSTF,
324 : CJCT
325 : };
326 :
327 : static const hb_tag_t indic_other_features[] =
328 : {
329 : HB_TAG('p','r','e','s'),
330 : HB_TAG('a','b','v','s'),
331 : HB_TAG('b','l','w','s'),
332 : HB_TAG('p','s','t','s'),
333 : HB_TAG('h','a','l','n'),
334 :
335 : HB_TAG('d','i','s','t'),
336 : HB_TAG('a','b','v','m'),
337 : HB_TAG('b','l','w','m'),
338 : };
339 :
340 :
341 : static void
342 : initial_reordering (const hb_ot_map_t *map,
343 : hb_face_t *face,
344 : hb_buffer_t *buffer,
345 : void *user_data HB_UNUSED);
346 : static void
347 : final_reordering (const hb_ot_map_t *map,
348 : hb_face_t *face,
349 : hb_buffer_t *buffer,
350 : void *user_data HB_UNUSED);
351 :
352 : void
353 0 : _hb_ot_shape_complex_collect_features_indic (hb_ot_map_builder_t *map, const hb_segment_properties_t *props)
354 : {
355 0 : map->add_bool_feature (HB_TAG('l','o','c','l'));
356 : /* The Indic specs do not require ccmp, but we apply it here since if
357 : * there is a use of it, it's typically at the beginning. */
358 0 : map->add_bool_feature (HB_TAG('c','c','m','p'));
359 :
360 0 : map->add_gsub_pause (initial_reordering, NULL);
361 :
362 0 : for (unsigned int i = 0; i < ARRAY_LENGTH (indic_basic_features); i++)
363 0 : map->add_bool_feature (indic_basic_features[i].tag, indic_basic_features[i].is_global);
364 :
365 0 : map->add_gsub_pause (final_reordering, NULL);
366 :
367 0 : for (unsigned int i = 0; i < ARRAY_LENGTH (indic_other_features); i++)
368 0 : map->add_bool_feature (indic_other_features[i], true);
369 0 : }
370 :
371 :
372 : bool
373 0 : _hb_ot_shape_complex_prefer_decomposed_indic (void)
374 : {
375 : /* We want split matras decomposed by the common shaping logic. */
376 0 : return TRUE;
377 : }
378 :
379 :
380 : void
381 0 : _hb_ot_shape_complex_setup_masks_indic (hb_ot_map_t *map, hb_buffer_t *buffer)
382 : {
383 0 : HB_BUFFER_ALLOCATE_VAR (buffer, indic_category);
384 0 : HB_BUFFER_ALLOCATE_VAR (buffer, indic_position);
385 :
386 : /* We cannot setup masks here. We save information about characters
387 : * and setup masks later on in a pause-callback. */
388 :
389 0 : unsigned int count = buffer->len;
390 0 : for (unsigned int i = 0; i < count; i++)
391 : {
392 0 : unsigned int type = get_indic_categories (buffer->info[i].codepoint);
393 :
394 0 : buffer->info[i].indic_category() = type & 0x0F;
395 0 : buffer->info[i].indic_position() = type >> 4;
396 :
397 0 : if (buffer->info[i].indic_category() == OT_C) {
398 0 : buffer->info[i].indic_position() = consonant_position (buffer->info[i].codepoint);
399 0 : if (is_ra (buffer->info[i].codepoint))
400 0 : buffer->info[i].indic_category() = OT_Ra;
401 0 : } else if (buffer->info[i].codepoint == 0x200C)
402 0 : buffer->info[i].indic_category() = OT_ZWNJ;
403 0 : else if (buffer->info[i].codepoint == 0x200D)
404 0 : buffer->info[i].indic_category() = OT_ZWJ;
405 : }
406 0 : }
407 :
408 : static int
409 0 : compare_indic_order (const hb_glyph_info_t *pa, const hb_glyph_info_t *pb)
410 : {
411 0 : int a = pa->indic_position();
412 0 : int b = pb->indic_position();
413 :
414 0 : return a < b ? -1 : a == b ? 0 : +1;
415 : }
416 :
417 : static void
418 0 : found_consonant_syllable (const hb_ot_map_t *map, hb_buffer_t *buffer, hb_mask_t *mask_array,
419 : unsigned int start, unsigned int end)
420 : {
421 : unsigned int i;
422 0 : hb_glyph_info_t *info = buffer->info;
423 :
424 : /* Comments from:
425 : * https://www.microsoft.com/typography/otfntdev/devanot/shaping.aspx */
426 :
427 : /* 1. Find base consonant:
428 : *
429 : * The shaping engine finds the base consonant of the syllable, using the
430 : * following algorithm: starting from the end of the syllable, move backwards
431 : * until a consonant is found that does not have a below-base or post-base
432 : * form (post-base forms have to follow below-base forms), or that is not a
433 : * pre-base reordering Ra, or arrive at the first consonant. The consonant
434 : * stopped at will be the base.
435 : *
436 : * o If the syllable starts with Ra + Halant (in a script that has Reph)
437 : * and has more than one consonant, Ra is excluded from candidates for
438 : * base consonants.
439 : */
440 :
441 0 : unsigned int base = end;
442 :
443 : /* -> starting from the end of the syllable, move backwards */
444 0 : i = end;
445 0 : unsigned int limit = start;
446 0 : if (info[start].indic_category() == OT_Ra && start + 2 <= end) {
447 0 : limit += 2;
448 0 : base = start;
449 : };
450 0 : do {
451 0 : i--;
452 : /* -> until a consonant is found */
453 0 : if (is_consonant (info[i]))
454 : {
455 : /* -> that does not have a below-base or post-base form
456 : * (post-base forms have to follow below-base forms), */
457 0 : if (info[i].indic_position() != POS_BELOW &&
458 0 : info[i].indic_position() != POS_POST)
459 : {
460 0 : base = i;
461 0 : break;
462 : }
463 :
464 : /* -> or that is not a pre-base reordering Ra,
465 : *
466 : * TODO
467 : */
468 :
469 : /* -> o If the syllable starts with Ra + Halant (in a script that has Reph)
470 : * and has more than one consonant, Ra is excluded from candidates for
471 : * base consonants.
472 : *
473 : * IMPLEMENTATION NOTES:
474 : *
475 : * We do this by adjusting limit accordingly before entering the loop.
476 : */
477 :
478 : /* -> or arrive at the first consonant. The consonant stopped at will
479 : * be the base. */
480 0 : base = i;
481 : }
482 : else
483 0 : if (is_joiner (info[i]))
484 0 : break;
485 : } while (i > limit);
486 0 : if (base < start)
487 0 : base = start; /* Just in case... */
488 :
489 :
490 : /* 2. Decompose and reorder Matras:
491 : *
492 : * Each matra and any syllable modifier sign in the cluster are moved to the
493 : * appropriate position relative to the consonant(s) in the cluster. The
494 : * shaping engine decomposes two- or three-part matras into their constituent
495 : * parts before any repositioning. Matra characters are classified by which
496 : * consonant in a conjunct they have affinity for and are reordered to the
497 : * following positions:
498 : *
499 : * o Before first half form in the syllable
500 : * o After subjoined consonants
501 : * o After post-form consonant
502 : * o After main consonant (for above marks)
503 : *
504 : * IMPLEMENTATION NOTES:
505 : *
506 : * The normalize() routine has already decomposed matras for us, so we don't
507 : * need to worry about that.
508 : */
509 :
510 :
511 : /* 3. Reorder marks to canonical order:
512 : *
513 : * Adjacent nukta and halant or nukta and vedic sign are always repositioned
514 : * if necessary, so that the nukta is first.
515 : *
516 : * IMPLEMENTATION NOTES:
517 : *
518 : * We don't need to do this: the normalize() routine already did this for us.
519 : */
520 :
521 :
522 : /* Reorder characters */
523 :
524 0 : for (i = start; i < base; i++)
525 0 : info[i].indic_position() = POS_PRE;
526 0 : info[base].indic_position() = POS_BASE;
527 :
528 :
529 : /* Handle beginning Ra */
530 0 : if (start + 3 <= end &&
531 0 : info[start].indic_category() == OT_Ra &&
532 0 : info[start + 1].indic_category() == OT_H &&
533 0 : !is_joiner (info[start + 2]))
534 : {
535 0 : info[start].indic_position() = POS_POST;
536 0 : info[start].mask = mask_array[RPHF];
537 : }
538 :
539 : /* For old-style Indic script tags, move the first post-base Halant after
540 : * last consonant. */
541 0 : if ((map->get_chosen_script (0) & 0x000000FF) != '2') {
542 : /* We should only do this for Indic scripts which have a version two I guess. */
543 0 : for (i = base + 1; i < end; i++)
544 0 : if (info[i].indic_category() == OT_H) {
545 : unsigned int j;
546 0 : for (j = end - 1; j > i; j--)
547 0 : if ((FLAG (info[j].indic_category()) & (FLAG (OT_C) | FLAG (OT_Ra))))
548 0 : break;
549 0 : if (j > i) {
550 : /* Move Halant to after last consonant. */
551 0 : hb_glyph_info_t t = info[i];
552 0 : memmove (&info[i], &info[i + 1], (j - i) * sizeof (info[0]));
553 0 : info[j] = t;
554 : }
555 0 : break;
556 : }
557 : }
558 :
559 : /* Attach ZWJ, ZWNJ, nukta, and halant to previous char to move with them. */
560 0 : for (i = start + 1; i < end; i++)
561 0 : if ((FLAG (info[i].indic_category()) &
562 : (FLAG (OT_ZWNJ) | FLAG (OT_ZWJ) | FLAG (OT_N) | FLAG (OT_H))))
563 0 : info[i].indic_position() = info[i - 1].indic_position();
564 :
565 : /* We do bubble-sort, skip malicious clusters attempts */
566 0 : if (end - start > 20)
567 0 : return;
568 :
569 : /* Sit tight, rock 'n roll! */
570 0 : hb_bubble_sort (info + start, end - start, compare_indic_order);
571 :
572 : /* Setup masks now */
573 :
574 : {
575 : hb_mask_t mask;
576 :
577 : /* Pre-base */
578 0 : mask = mask_array[HALF] | mask_array[AKHN] | mask_array[CJCT];
579 0 : for (i = start; i < base; i++)
580 0 : info[i].mask |= mask;
581 : /* Base */
582 0 : mask = mask_array[AKHN] | mask_array[CJCT];
583 0 : info[base].mask |= mask;
584 : /* Post-base */
585 0 : mask = mask_array[BLWF] | mask_array[PSTF] | mask_array[CJCT];
586 0 : for (i = base + 1; i < end; i++)
587 0 : info[i].mask |= mask;
588 : }
589 :
590 : /* Apply ZWJ/ZWNJ effects */
591 0 : for (i = start + 1; i < end; i++)
592 0 : if (is_joiner (info[i])) {
593 0 : bool non_joiner = info[i].indic_category() == OT_ZWNJ;
594 0 : unsigned int j = i;
595 :
596 0 : do {
597 0 : j--;
598 :
599 : /* Reading the Unicode and OpenType specs, I think the following line
600 : * is correct, but this is not what the test suite expects currently.
601 : * The test suite has been drinking, not me... But disable while
602 : * investigating.
603 : */
604 : //info[j].mask &= !mask_array[CJCT];
605 0 : if (non_joiner)
606 0 : info[j].mask &= !mask_array[HALF];
607 :
608 0 : } while (j > start && !is_consonant (info[j]));
609 : }
610 : }
611 :
612 :
613 : static void
614 0 : found_vowel_syllable (const hb_ot_map_t *map, hb_buffer_t *buffer, hb_mask_t *mask_array,
615 : unsigned int start, unsigned int end)
616 : {
617 : /* TODO
618 : * Not clear to me how this should work. Do the matras move to before the
619 : * independent vowel? No idea.
620 : */
621 0 : }
622 :
623 : static void
624 0 : found_standalone_cluster (const hb_ot_map_t *map, hb_buffer_t *buffer, hb_mask_t *mask_array,
625 : unsigned int start, unsigned int end)
626 : {
627 : /* TODO
628 : * Easiest thing to do here is to convert the NBSP to consonant and
629 : * call found_consonant_syllable.
630 : */
631 0 : }
632 :
633 : static void
634 0 : found_non_indic (const hb_ot_map_t *map, hb_buffer_t *buffer, hb_mask_t *mask_array,
635 : unsigned int start, unsigned int end)
636 : {
637 : /* Nothing to do right now. If we ever switch to using the output
638 : * buffer in the reordering process, we'd need to next_glyph() here. */
639 0 : }
640 :
641 : #include "hb-ot-shape-complex-indic-machine.hh"
642 :
643 : static void
644 0 : remove_joiners (hb_buffer_t *buffer)
645 : {
646 : /* For now we remove joiners. However, Uniscbire seems to keep them
647 : * and output a zero-width space glyph for them. It is not clear to
648 : * me how that is supposed to interact with GSUB. */
649 :
650 0 : buffer->clear_output ();
651 0 : unsigned int count = buffer->len;
652 0 : for (buffer->idx = 0; buffer->idx < count;)
653 0 : if (unlikely (is_joiner (buffer->info[buffer->idx])))
654 0 : buffer->skip_glyph ();
655 : else
656 0 : buffer->next_glyph ();
657 :
658 0 : buffer->swap_buffers ();
659 0 : }
660 :
661 : static void
662 0 : initial_reordering (const hb_ot_map_t *map,
663 : hb_face_t *face,
664 : hb_buffer_t *buffer,
665 : void *user_data HB_UNUSED)
666 : {
667 0 : hb_mask_t mask_array[ARRAY_LENGTH (indic_basic_features)] = {0};
668 0 : unsigned int num_masks = ARRAY_LENGTH (indic_basic_features);
669 0 : for (unsigned int i = 0; i < num_masks; i++)
670 0 : mask_array[i] = map->get_1_mask (indic_basic_features[i].tag);
671 :
672 0 : find_syllables (map, buffer, mask_array);
673 :
674 0 : remove_joiners (buffer);
675 0 : }
676 :
677 : static void
678 0 : final_reordering (const hb_ot_map_t *map,
679 : hb_face_t *face,
680 : hb_buffer_t *buffer,
681 : void *user_data HB_UNUSED)
682 : {
683 : /* 4. Final reordering:
684 : *
685 : * After the localized forms and basic shaping forms GSUB features have been
686 : * applied (see below), the shaping engine performs some final glyph
687 : * reordering before applying all the remaining font features to the entire
688 : * cluster.
689 : *
690 : * o Reorder matras:
691 : *
692 : * If a pre-base matra character had been reordered before applying basic
693 : * features, the glyph can be moved closer to the main consonant based on
694 : * whether half-forms had been formed. Actual position for the matra is
695 : * defined as “after last standalone halant glyph, after initial matra
696 : * position and before the main consonant”. If ZWJ or ZWNJ follow this
697 : * halant, position is moved after it.
698 : *
699 : * o Reorder reph:
700 : *
701 : * Reph’s original position is always at the beginning of the syllable,
702 : * (i.e. it is not reordered at the character reordering stage). However,
703 : * it will be reordered according to the basic-forms shaping results.
704 : * Possible positions for reph, depending on the script, are; after main,
705 : * before post-base consonant forms, and after post-base consonant forms.
706 : *
707 : * 1. If reph should be positioned after post-base consonant forms,
708 : * proceed to step 5.
709 : *
710 : * 2. If the reph repositioning class is not after post-base: target
711 : * position is after the first explicit halant glyph between the
712 : * first post-reph consonant and last main consonant. If ZWJ or ZWNJ
713 : * are following this halant, position is moved after it. If such
714 : * position is found, this is the target position. Otherwise,
715 : * proceed to the next step.
716 : *
717 : * Note: in old-implementation fonts, where classifications were
718 : * fixed in shaping engine, there was no case where reph position
719 : * will be found on this step.
720 : *
721 : * 3. If reph should be repositioned after the main consonant: from the
722 : * first consonant not ligated with main, or find the first
723 : * consonant that is not a potential pre-base reordering Ra.
724 : *
725 : *
726 : * 4. If reph should be positioned before post-base consonant, find
727 : * first post-base classified consonant not ligated with main. If no
728 : * consonant is found, the target position should be before the
729 : * first matra, syllable modifier sign or vedic sign.
730 : *
731 : * 5. If no consonant is found in steps 3 or 4, move reph to a position
732 : * immediately before the first post-base matra, syllable modifier
733 : * sign or vedic sign that has a reordering class after the intended
734 : * reph position. For example, if the reordering position for reph
735 : * is post-main, it will skip above-base matras that also have a
736 : * post-main position.
737 : *
738 : * 6. Otherwise, reorder reph to the end of the syllable.
739 : *
740 : * o Reorder pre-base reordering consonants:
741 : *
742 : * If a pre-base reordering consonant is found, reorder it according to
743 : * the following rules:
744 : *
745 : * 1. Only reorder a glyph produced by substitution during application
746 : * of the feature. (Note that a font may shape a Ra consonant with
747 : * the feature generally but block it in certain contexts.)
748 : *
749 : * 2. Try to find a target position the same way as for pre-base matra.
750 : * If it is found, reorder pre-base consonant glyph.
751 : *
752 : * 3. If position is not found, reorder immediately before main
753 : * consonant.
754 : */
755 :
756 : /* TODO */
757 :
758 :
759 :
760 0 : HB_BUFFER_DEALLOCATE_VAR (buffer, indic_category);
761 0 : HB_BUFFER_DEALLOCATE_VAR (buffer, indic_position);
762 0 : }
763 :
764 :
765 :
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