Line data Source code
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 : #include "hb-ot-shape-complex-indic-private.hh"
28 : #include "hb-ot-layout-private.hh"
29 :
30 : /* buffer var allocations */
31 : #define indic_category() complex_var_u8_0() /* indic_category_t */
32 : #define indic_position() complex_var_u8_1() /* indic_position_t */
33 :
34 :
35 : /*
36 : * Indic shaper.
37 : */
38 :
39 :
40 : #define IN_HALF_BLOCK(u, Base) (((u) & ~0x7Fu) == (Base))
41 :
42 : #define IS_DEVA(u) (IN_HALF_BLOCK (u, 0x0900u))
43 : #define IS_BENG(u) (IN_HALF_BLOCK (u, 0x0980u))
44 : #define IS_GURU(u) (IN_HALF_BLOCK (u, 0x0A00u))
45 : #define IS_GUJR(u) (IN_HALF_BLOCK (u, 0x0A80u))
46 : #define IS_ORYA(u) (IN_HALF_BLOCK (u, 0x0B00u))
47 : #define IS_TAML(u) (IN_HALF_BLOCK (u, 0x0B80u))
48 : #define IS_TELU(u) (IN_HALF_BLOCK (u, 0x0C00u))
49 : #define IS_KNDA(u) (IN_HALF_BLOCK (u, 0x0C80u))
50 : #define IS_MLYM(u) (IN_HALF_BLOCK (u, 0x0D00u))
51 : #define IS_SINH(u) (IN_HALF_BLOCK (u, 0x0D80u))
52 : #define IS_KHMR(u) (IN_HALF_BLOCK (u, 0x1780u))
53 :
54 :
55 : #define MATRA_POS_LEFT(u) POS_PRE_M
56 : #define MATRA_POS_RIGHT(u) ( \
57 : IS_DEVA(u) ? POS_AFTER_SUB : \
58 : IS_BENG(u) ? POS_AFTER_POST : \
59 : IS_GURU(u) ? POS_AFTER_POST : \
60 : IS_GUJR(u) ? POS_AFTER_POST : \
61 : IS_ORYA(u) ? POS_AFTER_POST : \
62 : IS_TAML(u) ? POS_AFTER_POST : \
63 : IS_TELU(u) ? (u <= 0x0C42u ? POS_BEFORE_SUB : POS_AFTER_SUB) : \
64 : IS_KNDA(u) ? (u < 0x0CC3u || u > 0xCD6u ? POS_BEFORE_SUB : POS_AFTER_SUB) : \
65 : IS_MLYM(u) ? POS_AFTER_POST : \
66 : IS_SINH(u) ? POS_AFTER_SUB : \
67 : IS_KHMR(u) ? POS_AFTER_POST : \
68 : /*default*/ POS_AFTER_SUB \
69 : )
70 : #define MATRA_POS_TOP(u) ( /* BENG and MLYM don't have top matras. */ \
71 : IS_DEVA(u) ? POS_AFTER_SUB : \
72 : IS_GURU(u) ? POS_AFTER_POST : /* Deviate from spec */ \
73 : IS_GUJR(u) ? POS_AFTER_SUB : \
74 : IS_ORYA(u) ? POS_AFTER_MAIN : \
75 : IS_TAML(u) ? POS_AFTER_SUB : \
76 : IS_TELU(u) ? POS_BEFORE_SUB : \
77 : IS_KNDA(u) ? POS_BEFORE_SUB : \
78 : IS_SINH(u) ? POS_AFTER_SUB : \
79 : IS_KHMR(u) ? POS_AFTER_POST : \
80 : /*default*/ POS_AFTER_SUB \
81 : )
82 : #define MATRA_POS_BOTTOM(u) ( \
83 : IS_DEVA(u) ? POS_AFTER_SUB : \
84 : IS_BENG(u) ? POS_AFTER_SUB : \
85 : IS_GURU(u) ? POS_AFTER_POST : \
86 : IS_GUJR(u) ? POS_AFTER_POST : \
87 : IS_ORYA(u) ? POS_AFTER_SUB : \
88 : IS_TAML(u) ? POS_AFTER_POST : \
89 : IS_TELU(u) ? POS_BEFORE_SUB : \
90 : IS_KNDA(u) ? POS_BEFORE_SUB : \
91 : IS_MLYM(u) ? POS_AFTER_POST : \
92 : IS_SINH(u) ? POS_AFTER_SUB : \
93 : IS_KHMR(u) ? POS_AFTER_POST : \
94 : /*default*/ POS_AFTER_SUB \
95 : )
96 :
97 : static inline indic_position_t
98 0 : matra_position (hb_codepoint_t u, indic_position_t side)
99 : {
100 0 : switch ((int) side)
101 : {
102 0 : case POS_PRE_C: return MATRA_POS_LEFT (u);
103 0 : case POS_POST_C: return MATRA_POS_RIGHT (u);
104 0 : case POS_ABOVE_C: return MATRA_POS_TOP (u);
105 0 : case POS_BELOW_C: return MATRA_POS_BOTTOM (u);
106 : };
107 0 : return side;
108 : }
109 :
110 : /* XXX
111 : * This is a hack for now. We should move this data into the main Indic table.
112 : * Or completely remove it and just check in the tables.
113 : */
114 : static const hb_codepoint_t ra_chars[] = {
115 : 0x0930u, /* Devanagari */
116 : 0x09B0u, /* Bengali */
117 : 0x09F0u, /* Bengali */
118 : 0x0A30u, /* Gurmukhi */ /* No Reph */
119 : 0x0AB0u, /* Gujarati */
120 : 0x0B30u, /* Oriya */
121 : 0x0BB0u, /* Tamil */ /* No Reph */
122 : 0x0C30u, /* Telugu */ /* Reph formed only with ZWJ */
123 : 0x0CB0u, /* Kannada */
124 : 0x0D30u, /* Malayalam */ /* No Reph, Logical Repha */
125 :
126 : 0x0DBBu, /* Sinhala */ /* Reph formed only with ZWJ */
127 :
128 : 0x179Au, /* Khmer */ /* No Reph, Visual Repha */
129 : };
130 :
131 : static inline bool
132 0 : is_ra (hb_codepoint_t u)
133 : {
134 0 : for (unsigned int i = 0; i < ARRAY_LENGTH (ra_chars); i++)
135 0 : if (u == ra_chars[i])
136 0 : return true;
137 0 : return false;
138 : }
139 :
140 : static inline bool
141 0 : is_one_of (const hb_glyph_info_t &info, unsigned int flags)
142 : {
143 : /* If it ligated, all bets are off. */
144 0 : if (_hb_glyph_info_ligated (&info)) return false;
145 0 : return !!(FLAG_SAFE (info.indic_category()) & flags);
146 : }
147 :
148 : static inline bool
149 0 : is_joiner (const hb_glyph_info_t &info)
150 : {
151 0 : return is_one_of (info, JOINER_FLAGS);
152 : }
153 :
154 : static inline bool
155 0 : is_consonant (const hb_glyph_info_t &info)
156 : {
157 0 : return is_one_of (info, CONSONANT_FLAGS);
158 : }
159 :
160 : static inline bool
161 0 : is_halant_or_coeng (const hb_glyph_info_t &info)
162 : {
163 0 : return is_one_of (info, HALANT_OR_COENG_FLAGS);
164 : }
165 :
166 : static inline void
167 0 : set_indic_properties (hb_glyph_info_t &info)
168 : {
169 0 : hb_codepoint_t u = info.codepoint;
170 0 : unsigned int type = hb_indic_get_categories (u);
171 0 : indic_category_t cat = (indic_category_t) (type & 0x7Fu);
172 0 : indic_position_t pos = (indic_position_t) (type >> 8);
173 :
174 :
175 : /*
176 : * Re-assign category
177 : */
178 :
179 : /* The following act more like the Bindus. */
180 0 : if (unlikely (hb_in_range (u, 0x0953u, 0x0954u)))
181 0 : cat = OT_SM;
182 : /* The following act like consonants. */
183 0 : else if (unlikely (hb_in_ranges (u, 0x0A72u, 0x0A73u,
184 : 0x1CF5u, 0x1CF6u)))
185 0 : cat = OT_C;
186 : /* TODO: The following should only be allowed after a Visarga.
187 : * For now, just treat them like regular tone marks. */
188 0 : else if (unlikely (hb_in_range (u, 0x1CE2u, 0x1CE8u)))
189 0 : cat = OT_A;
190 : /* TODO: The following should only be allowed after some of
191 : * the nasalization marks, maybe only for U+1CE9..U+1CF1.
192 : * For now, just treat them like tone marks. */
193 0 : else if (unlikely (u == 0x1CEDu))
194 0 : cat = OT_A;
195 : /* The following take marks in standalone clusters, similar to Avagraha. */
196 0 : else if (unlikely (hb_in_ranges (u, 0xA8F2u, 0xA8F7u,
197 : 0x1CE9u, 0x1CECu,
198 : 0x1CEEu, 0x1CF1u)))
199 : {
200 0 : cat = OT_Symbol;
201 : ASSERT_STATIC ((int) INDIC_SYLLABIC_CATEGORY_AVAGRAHA == OT_Symbol);
202 : }
203 0 : else if (unlikely (u == 0x17C6u)) cat = OT_N; /* Khmer Bindu doesn't like to be repositioned. */
204 0 : else if (unlikely (hb_in_range (u, 0x2010u, 0x2011u)))
205 0 : cat = OT_PLACEHOLDER;
206 0 : else if (unlikely (u == 0x25CCu)) cat = OT_DOTTEDCIRCLE;
207 :
208 :
209 : /*
210 : * Re-assign position.
211 : */
212 :
213 0 : if ((FLAG_SAFE (cat) & CONSONANT_FLAGS))
214 : {
215 0 : pos = POS_BASE_C;
216 0 : if (is_ra (u))
217 0 : cat = OT_Ra;
218 : }
219 0 : else if (cat == OT_M)
220 : {
221 0 : pos = matra_position (u, pos);
222 : }
223 0 : else if ((FLAG_SAFE (cat) & (FLAG (OT_SM) | FLAG (OT_VD) | FLAG (OT_A) | FLAG (OT_Symbol))))
224 : {
225 0 : pos = POS_SMVD;
226 : }
227 :
228 0 : if (unlikely (u == 0x0B01u)) pos = POS_BEFORE_SUB; /* Oriya Bindu is BeforeSub in the spec. */
229 :
230 :
231 :
232 0 : info.indic_category() = cat;
233 0 : info.indic_position() = pos;
234 0 : }
235 :
236 : /*
237 : * Things above this line should ideally be moved to the Indic table itself.
238 : */
239 :
240 :
241 : /*
242 : * Indic configurations. Note that we do not want to keep every single script-specific
243 : * behavior in these tables necessarily. This should mainly be used for per-script
244 : * properties that are cheaper keeping here, than in the code. Ie. if, say, one and
245 : * only one script has an exception, that one script can be if'ed directly in the code,
246 : * instead of adding a new flag in these structs.
247 : */
248 :
249 : enum base_position_t {
250 : BASE_POS_FIRST,
251 : BASE_POS_LAST_SINHALA,
252 : BASE_POS_LAST
253 : };
254 : enum reph_position_t {
255 : REPH_POS_AFTER_MAIN = POS_AFTER_MAIN,
256 : REPH_POS_BEFORE_SUB = POS_BEFORE_SUB,
257 : REPH_POS_AFTER_SUB = POS_AFTER_SUB,
258 : REPH_POS_BEFORE_POST = POS_BEFORE_POST,
259 : REPH_POS_AFTER_POST = POS_AFTER_POST,
260 : REPH_POS_DONT_CARE = POS_RA_TO_BECOME_REPH
261 : };
262 : enum reph_mode_t {
263 : REPH_MODE_IMPLICIT, /* Reph formed out of initial Ra,H sequence. */
264 : REPH_MODE_EXPLICIT, /* Reph formed out of initial Ra,H,ZWJ sequence. */
265 : REPH_MODE_VIS_REPHA, /* Encoded Repha character, no reordering needed. */
266 : REPH_MODE_LOG_REPHA /* Encoded Repha character, needs reordering. */
267 : };
268 : enum blwf_mode_t {
269 : BLWF_MODE_PRE_AND_POST, /* Below-forms feature applied to pre-base and post-base. */
270 : BLWF_MODE_POST_ONLY /* Below-forms feature applied to post-base only. */
271 : };
272 : struct indic_config_t
273 : {
274 : hb_script_t script;
275 : bool has_old_spec;
276 : hb_codepoint_t virama;
277 : base_position_t base_pos;
278 : reph_position_t reph_pos;
279 : reph_mode_t reph_mode;
280 : blwf_mode_t blwf_mode;
281 : };
282 :
283 : static const indic_config_t indic_configs[] =
284 : {
285 : /* Default. Should be first. */
286 : {HB_SCRIPT_INVALID, false, 0,BASE_POS_LAST, REPH_POS_BEFORE_POST,REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST},
287 : {HB_SCRIPT_DEVANAGARI,true, 0x094Du,BASE_POS_LAST, REPH_POS_BEFORE_POST,REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST},
288 : {HB_SCRIPT_BENGALI, true, 0x09CDu,BASE_POS_LAST, REPH_POS_AFTER_SUB, REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST},
289 : {HB_SCRIPT_GURMUKHI, true, 0x0A4Du,BASE_POS_LAST, REPH_POS_BEFORE_SUB, REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST},
290 : {HB_SCRIPT_GUJARATI, true, 0x0ACDu,BASE_POS_LAST, REPH_POS_BEFORE_POST,REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST},
291 : {HB_SCRIPT_ORIYA, true, 0x0B4Du,BASE_POS_LAST, REPH_POS_AFTER_MAIN, REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST},
292 : {HB_SCRIPT_TAMIL, true, 0x0BCDu,BASE_POS_LAST, REPH_POS_AFTER_POST, REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST},
293 : {HB_SCRIPT_TELUGU, true, 0x0C4Du,BASE_POS_LAST, REPH_POS_AFTER_POST, REPH_MODE_EXPLICIT, BLWF_MODE_POST_ONLY},
294 : {HB_SCRIPT_KANNADA, true, 0x0CCDu,BASE_POS_LAST, REPH_POS_AFTER_POST, REPH_MODE_IMPLICIT, BLWF_MODE_POST_ONLY},
295 : {HB_SCRIPT_MALAYALAM, true, 0x0D4Du,BASE_POS_LAST, REPH_POS_AFTER_MAIN, REPH_MODE_LOG_REPHA,BLWF_MODE_PRE_AND_POST},
296 : {HB_SCRIPT_SINHALA, false,0x0DCAu,BASE_POS_LAST_SINHALA,
297 : REPH_POS_AFTER_MAIN, REPH_MODE_EXPLICIT, BLWF_MODE_PRE_AND_POST},
298 : {HB_SCRIPT_KHMER, false,0x17D2u,BASE_POS_FIRST,REPH_POS_DONT_CARE, REPH_MODE_VIS_REPHA,BLWF_MODE_PRE_AND_POST},
299 : };
300 :
301 :
302 :
303 : /*
304 : * Indic shaper.
305 : */
306 :
307 : struct feature_list_t {
308 : hb_tag_t tag;
309 : hb_ot_map_feature_flags_t flags;
310 : };
311 :
312 : static const feature_list_t
313 : indic_features[] =
314 : {
315 : /*
316 : * Basic features.
317 : * These features are applied in order, one at a time, after initial_reordering.
318 : */
319 : {HB_TAG('n','u','k','t'), F_GLOBAL},
320 : {HB_TAG('a','k','h','n'), F_GLOBAL},
321 : {HB_TAG('r','p','h','f'), F_NONE},
322 : {HB_TAG('r','k','r','f'), F_GLOBAL},
323 : {HB_TAG('p','r','e','f'), F_NONE},
324 : {HB_TAG('b','l','w','f'), F_NONE},
325 : {HB_TAG('a','b','v','f'), F_NONE},
326 : {HB_TAG('h','a','l','f'), F_NONE},
327 : {HB_TAG('p','s','t','f'), F_NONE},
328 : {HB_TAG('v','a','t','u'), F_GLOBAL},
329 : {HB_TAG('c','j','c','t'), F_GLOBAL},
330 : {HB_TAG('c','f','a','r'), F_NONE},
331 : /*
332 : * Other features.
333 : * These features are applied all at once, after final_reordering.
334 : * Default Bengali font in Windows for example has intermixed
335 : * lookups for init,pres,abvs,blws features.
336 : */
337 : {HB_TAG('i','n','i','t'), F_NONE},
338 : {HB_TAG('p','r','e','s'), F_GLOBAL},
339 : {HB_TAG('a','b','v','s'), F_GLOBAL},
340 : {HB_TAG('b','l','w','s'), F_GLOBAL},
341 : {HB_TAG('p','s','t','s'), F_GLOBAL},
342 : {HB_TAG('h','a','l','n'), F_GLOBAL},
343 : /* Positioning features, though we don't care about the types. */
344 : {HB_TAG('d','i','s','t'), F_GLOBAL},
345 : {HB_TAG('a','b','v','m'), F_GLOBAL},
346 : {HB_TAG('b','l','w','m'), F_GLOBAL},
347 : };
348 :
349 : /*
350 : * Must be in the same order as the indic_features array.
351 : */
352 : enum {
353 : _NUKT,
354 : _AKHN,
355 : RPHF,
356 : _RKRF,
357 : PREF,
358 : BLWF,
359 : ABVF,
360 : HALF,
361 : PSTF,
362 : _VATU,
363 : _CJCT,
364 : CFAR,
365 :
366 : INIT,
367 : _PRES,
368 : _ABVS,
369 : _BLWS,
370 : _PSTS,
371 : _HALN,
372 : _DIST,
373 : _ABVM,
374 : _BLWM,
375 :
376 : INDIC_NUM_FEATURES,
377 : INDIC_BASIC_FEATURES = INIT /* Don't forget to update this! */
378 : };
379 :
380 : static void
381 : setup_syllables (const hb_ot_shape_plan_t *plan,
382 : hb_font_t *font,
383 : hb_buffer_t *buffer);
384 : static void
385 : initial_reordering (const hb_ot_shape_plan_t *plan,
386 : hb_font_t *font,
387 : hb_buffer_t *buffer);
388 : static void
389 : final_reordering (const hb_ot_shape_plan_t *plan,
390 : hb_font_t *font,
391 : hb_buffer_t *buffer);
392 : static void
393 : clear_syllables (const hb_ot_shape_plan_t *plan,
394 : hb_font_t *font,
395 : hb_buffer_t *buffer);
396 :
397 : static void
398 0 : collect_features_indic (hb_ot_shape_planner_t *plan)
399 : {
400 0 : hb_ot_map_builder_t *map = &plan->map;
401 :
402 : /* Do this before any lookups have been applied. */
403 0 : map->add_gsub_pause (setup_syllables);
404 :
405 0 : map->add_global_bool_feature (HB_TAG('l','o','c','l'));
406 : /* The Indic specs do not require ccmp, but we apply it here since if
407 : * there is a use of it, it's typically at the beginning. */
408 0 : map->add_global_bool_feature (HB_TAG('c','c','m','p'));
409 :
410 :
411 0 : unsigned int i = 0;
412 0 : map->add_gsub_pause (initial_reordering);
413 0 : for (; i < INDIC_BASIC_FEATURES; i++) {
414 0 : map->add_feature (indic_features[i].tag, 1, indic_features[i].flags | F_MANUAL_ZWJ);
415 0 : map->add_gsub_pause (NULL);
416 : }
417 0 : map->add_gsub_pause (final_reordering);
418 0 : for (; i < INDIC_NUM_FEATURES; i++) {
419 0 : map->add_feature (indic_features[i].tag, 1, indic_features[i].flags | F_MANUAL_ZWJ);
420 : }
421 :
422 0 : map->add_global_bool_feature (HB_TAG('c','a','l','t'));
423 0 : map->add_global_bool_feature (HB_TAG('c','l','i','g'));
424 :
425 0 : map->add_gsub_pause (clear_syllables);
426 0 : }
427 :
428 : static void
429 0 : override_features_indic (hb_ot_shape_planner_t *plan)
430 : {
431 : /* Uniscribe does not apply 'kern' in Khmer. */
432 0 : if (hb_options ().uniscribe_bug_compatible)
433 : {
434 0 : switch ((hb_tag_t) plan->props.script)
435 : {
436 : case HB_SCRIPT_KHMER:
437 0 : plan->map.add_feature (HB_TAG('k','e','r','n'), 0, F_GLOBAL);
438 0 : break;
439 : }
440 : }
441 :
442 0 : plan->map.add_feature (HB_TAG('l','i','g','a'), 0, F_GLOBAL);
443 0 : }
444 :
445 :
446 : struct would_substitute_feature_t
447 : {
448 0 : inline void init (const hb_ot_map_t *map, hb_tag_t feature_tag, bool zero_context_)
449 : {
450 0 : zero_context = zero_context_;
451 0 : map->get_stage_lookups (0/*GSUB*/,
452 : map->get_feature_stage (0/*GSUB*/, feature_tag),
453 0 : &lookups, &count);
454 0 : }
455 :
456 0 : inline bool would_substitute (const hb_codepoint_t *glyphs,
457 : unsigned int glyphs_count,
458 : hb_face_t *face) const
459 : {
460 0 : for (unsigned int i = 0; i < count; i++)
461 0 : if (hb_ot_layout_lookup_would_substitute_fast (face, lookups[i].index, glyphs, glyphs_count, zero_context))
462 0 : return true;
463 0 : return false;
464 : }
465 :
466 : private:
467 : const hb_ot_map_t::lookup_map_t *lookups;
468 : unsigned int count;
469 : bool zero_context;
470 : };
471 :
472 : struct indic_shape_plan_t
473 : {
474 : ASSERT_POD ();
475 :
476 0 : inline bool get_virama_glyph (hb_font_t *font, hb_codepoint_t *pglyph) const
477 : {
478 0 : hb_codepoint_t glyph = virama_glyph;
479 0 : if (unlikely (virama_glyph == (hb_codepoint_t) -1))
480 : {
481 0 : if (!config->virama || !font->get_nominal_glyph (config->virama, &glyph))
482 0 : glyph = 0;
483 : /* Technically speaking, the spec says we should apply 'locl' to virama too.
484 : * Maybe one day... */
485 :
486 : /* Our get_nominal_glyph() function needs a font, so we can't get the virama glyph
487 : * during shape planning... Instead, overwrite it here. It's safe. Don't worry! */
488 0 : (const_cast<indic_shape_plan_t *> (this))->virama_glyph = glyph;
489 : }
490 :
491 0 : *pglyph = glyph;
492 0 : return glyph != 0;
493 : }
494 :
495 : const indic_config_t *config;
496 :
497 : bool is_old_spec;
498 : hb_codepoint_t virama_glyph;
499 :
500 : would_substitute_feature_t rphf;
501 : would_substitute_feature_t pref;
502 : would_substitute_feature_t blwf;
503 : would_substitute_feature_t pstf;
504 :
505 : hb_mask_t mask_array[INDIC_NUM_FEATURES];
506 : };
507 :
508 : static void *
509 0 : data_create_indic (const hb_ot_shape_plan_t *plan)
510 : {
511 0 : indic_shape_plan_t *indic_plan = (indic_shape_plan_t *) calloc (1, sizeof (indic_shape_plan_t));
512 0 : if (unlikely (!indic_plan))
513 0 : return NULL;
514 :
515 0 : indic_plan->config = &indic_configs[0];
516 0 : for (unsigned int i = 1; i < ARRAY_LENGTH (indic_configs); i++)
517 0 : if (plan->props.script == indic_configs[i].script) {
518 0 : indic_plan->config = &indic_configs[i];
519 0 : break;
520 : }
521 :
522 0 : indic_plan->is_old_spec = indic_plan->config->has_old_spec && ((plan->map.chosen_script[0] & 0x000000FFu) != '2');
523 0 : indic_plan->virama_glyph = (hb_codepoint_t) -1;
524 :
525 : /* Use zero-context would_substitute() matching for new-spec of the main
526 : * Indic scripts, and scripts with one spec only, but not for old-specs.
527 : * The new-spec for all dual-spec scripts says zero-context matching happens.
528 : *
529 : * However, testing with Malayalam shows that old and new spec both allow
530 : * context. Testing with Bengali new-spec however shows that it doesn't.
531 : * So, the heuristic here is the way it is. It should *only* be changed,
532 : * as we discover more cases of what Windows does. DON'T TOUCH OTHERWISE.
533 : */
534 0 : bool zero_context = !indic_plan->is_old_spec && plan->props.script != HB_SCRIPT_MALAYALAM;
535 0 : indic_plan->rphf.init (&plan->map, HB_TAG('r','p','h','f'), zero_context);
536 0 : indic_plan->pref.init (&plan->map, HB_TAG('p','r','e','f'), zero_context);
537 0 : indic_plan->blwf.init (&plan->map, HB_TAG('b','l','w','f'), zero_context);
538 0 : indic_plan->pstf.init (&plan->map, HB_TAG('p','s','t','f'), zero_context);
539 :
540 0 : for (unsigned int i = 0; i < ARRAY_LENGTH (indic_plan->mask_array); i++)
541 0 : indic_plan->mask_array[i] = (indic_features[i].flags & F_GLOBAL) ?
542 0 : 0 : plan->map.get_1_mask (indic_features[i].tag);
543 :
544 0 : return indic_plan;
545 : }
546 :
547 : static void
548 0 : data_destroy_indic (void *data)
549 : {
550 0 : free (data);
551 0 : }
552 :
553 : static indic_position_t
554 0 : consonant_position_from_face (const indic_shape_plan_t *indic_plan,
555 : const hb_codepoint_t consonant,
556 : const hb_codepoint_t virama,
557 : hb_face_t *face)
558 : {
559 : /* For old-spec, the order of glyphs is Consonant,Virama,
560 : * whereas for new-spec, it's Virama,Consonant. However,
561 : * some broken fonts (like Free Sans) simply copied lookups
562 : * from old-spec to new-spec without modification.
563 : * And oddly enough, Uniscribe seems to respect those lookups.
564 : * Eg. in the sequence U+0924,U+094D,U+0930, Uniscribe finds
565 : * base at 0. The font however, only has lookups matching
566 : * 930,94D in 'blwf', not the expected 94D,930 (with new-spec
567 : * table). As such, we simply match both sequences. Seems
568 : * to work. */
569 0 : hb_codepoint_t glyphs[3] = {virama, consonant, virama};
570 0 : if (indic_plan->blwf.would_substitute (glyphs , 2, face) ||
571 0 : indic_plan->blwf.would_substitute (glyphs+1, 2, face))
572 0 : return POS_BELOW_C;
573 0 : if (indic_plan->pstf.would_substitute (glyphs , 2, face) ||
574 0 : indic_plan->pstf.would_substitute (glyphs+1, 2, face))
575 0 : return POS_POST_C;
576 0 : if (indic_plan->pref.would_substitute (glyphs , 2, face) ||
577 0 : indic_plan->pref.would_substitute (glyphs+1, 2, face))
578 0 : return POS_POST_C;
579 0 : return POS_BASE_C;
580 : }
581 :
582 :
583 : enum syllable_type_t {
584 : consonant_syllable,
585 : vowel_syllable,
586 : standalone_cluster,
587 : symbol_cluster,
588 : broken_cluster,
589 : non_indic_cluster,
590 : };
591 :
592 : #include "hb-ot-shape-complex-indic-machine.hh"
593 :
594 :
595 : static void
596 0 : setup_masks_indic (const hb_ot_shape_plan_t *plan HB_UNUSED,
597 : hb_buffer_t *buffer,
598 : hb_font_t *font HB_UNUSED)
599 : {
600 0 : HB_BUFFER_ALLOCATE_VAR (buffer, indic_category);
601 0 : HB_BUFFER_ALLOCATE_VAR (buffer, indic_position);
602 :
603 : /* We cannot setup masks here. We save information about characters
604 : * and setup masks later on in a pause-callback. */
605 :
606 0 : unsigned int count = buffer->len;
607 0 : hb_glyph_info_t *info = buffer->info;
608 0 : for (unsigned int i = 0; i < count; i++)
609 0 : set_indic_properties (info[i]);
610 0 : }
611 :
612 : static void
613 0 : setup_syllables (const hb_ot_shape_plan_t *plan HB_UNUSED,
614 : hb_font_t *font HB_UNUSED,
615 : hb_buffer_t *buffer)
616 : {
617 0 : find_syllables (buffer);
618 0 : }
619 :
620 : static int
621 0 : compare_indic_order (const hb_glyph_info_t *pa, const hb_glyph_info_t *pb)
622 : {
623 0 : int a = pa->indic_position();
624 0 : int b = pb->indic_position();
625 :
626 0 : return a < b ? -1 : a == b ? 0 : +1;
627 : }
628 :
629 :
630 :
631 : static void
632 0 : update_consonant_positions (const hb_ot_shape_plan_t *plan,
633 : hb_font_t *font,
634 : hb_buffer_t *buffer)
635 : {
636 0 : const indic_shape_plan_t *indic_plan = (const indic_shape_plan_t *) plan->data;
637 :
638 0 : if (indic_plan->config->base_pos != BASE_POS_LAST)
639 0 : return;
640 :
641 : hb_codepoint_t virama;
642 0 : if (indic_plan->get_virama_glyph (font, &virama))
643 : {
644 0 : hb_face_t *face = font->face;
645 0 : unsigned int count = buffer->len;
646 0 : hb_glyph_info_t *info = buffer->info;
647 0 : for (unsigned int i = 0; i < count; i++)
648 0 : if (info[i].indic_position() == POS_BASE_C)
649 : {
650 0 : hb_codepoint_t consonant = info[i].codepoint;
651 0 : info[i].indic_position() = consonant_position_from_face (indic_plan, consonant, virama, face);
652 : }
653 : }
654 : }
655 :
656 :
657 : /* Rules from:
658 : * https://www.microsoft.com/typography/otfntdev/devanot/shaping.aspx */
659 :
660 : static void
661 0 : initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan,
662 : hb_face_t *face,
663 : hb_buffer_t *buffer,
664 : unsigned int start, unsigned int end)
665 : {
666 0 : const indic_shape_plan_t *indic_plan = (const indic_shape_plan_t *) plan->data;
667 0 : hb_glyph_info_t *info = buffer->info;
668 :
669 :
670 : /* 1. Find base consonant:
671 : *
672 : * The shaping engine finds the base consonant of the syllable, using the
673 : * following algorithm: starting from the end of the syllable, move backwards
674 : * until a consonant is found that does not have a below-base or post-base
675 : * form (post-base forms have to follow below-base forms), or that is not a
676 : * pre-base reordering Ra, or arrive at the first consonant. The consonant
677 : * stopped at will be the base.
678 : *
679 : * o If the syllable starts with Ra + Halant (in a script that has Reph)
680 : * and has more than one consonant, Ra is excluded from candidates for
681 : * base consonants.
682 : */
683 :
684 0 : unsigned int base = end;
685 0 : bool has_reph = false;
686 :
687 : {
688 : /* -> If the syllable starts with Ra + Halant (in a script that has Reph)
689 : * and has more than one consonant, Ra is excluded from candidates for
690 : * base consonants. */
691 0 : unsigned int limit = start;
692 0 : if (indic_plan->config->reph_pos != REPH_POS_DONT_CARE &&
693 0 : indic_plan->mask_array[RPHF] &&
694 0 : start + 3 <= end &&
695 : (
696 0 : (indic_plan->config->reph_mode == REPH_MODE_IMPLICIT && !is_joiner (info[start + 2])) ||
697 0 : (indic_plan->config->reph_mode == REPH_MODE_EXPLICIT && info[start + 2].indic_category() == OT_ZWJ)
698 : ))
699 : {
700 : /* See if it matches the 'rphf' feature. */
701 0 : hb_codepoint_t glyphs[3] = {info[start].codepoint,
702 0 : info[start + 1].codepoint,
703 0 : indic_plan->config->reph_mode == REPH_MODE_EXPLICIT ?
704 0 : info[start + 2].codepoint : 0};
705 0 : if (indic_plan->rphf.would_substitute (glyphs, 2, face) ||
706 0 : (indic_plan->config->reph_mode == REPH_MODE_EXPLICIT &&
707 0 : indic_plan->rphf.would_substitute (glyphs, 3, face)))
708 : {
709 0 : limit += 2;
710 0 : while (limit < end && is_joiner (info[limit]))
711 0 : limit++;
712 0 : base = start;
713 0 : has_reph = true;
714 : }
715 0 : } else if (indic_plan->config->reph_mode == REPH_MODE_LOG_REPHA && info[start].indic_category() == OT_Repha)
716 : {
717 0 : limit += 1;
718 0 : while (limit < end && is_joiner (info[limit]))
719 0 : limit++;
720 0 : base = start;
721 0 : has_reph = true;
722 : }
723 :
724 0 : switch (indic_plan->config->base_pos)
725 : {
726 : case BASE_POS_LAST:
727 : {
728 : /* -> starting from the end of the syllable, move backwards */
729 0 : unsigned int i = end;
730 0 : bool seen_below = false;
731 0 : do {
732 0 : i--;
733 : /* -> until a consonant is found */
734 0 : if (is_consonant (info[i]))
735 : {
736 : /* -> that does not have a below-base or post-base form
737 : * (post-base forms have to follow below-base forms), */
738 0 : if (info[i].indic_position() != POS_BELOW_C &&
739 0 : (info[i].indic_position() != POS_POST_C || seen_below))
740 : {
741 0 : base = i;
742 0 : break;
743 : }
744 0 : if (info[i].indic_position() == POS_BELOW_C)
745 0 : seen_below = true;
746 :
747 : /* -> or that is not a pre-base reordering Ra,
748 : *
749 : * IMPLEMENTATION NOTES:
750 : *
751 : * Our pre-base reordering Ra's are marked POS_POST_C, so will be skipped
752 : * by the logic above already.
753 : */
754 :
755 : /* -> or arrive at the first consonant. The consonant stopped at will
756 : * be the base. */
757 0 : base = i;
758 : }
759 : else
760 : {
761 : /* A ZWJ after a Halant stops the base search, and requests an explicit
762 : * half form.
763 : * A ZWJ before a Halant, requests a subjoined form instead, and hence
764 : * search continues. This is particularly important for Bengali
765 : * sequence Ra,H,Ya that should form Ya-Phalaa by subjoining Ya. */
766 0 : if (start < i &&
767 0 : info[i].indic_category() == OT_ZWJ &&
768 0 : info[i - 1].indic_category() == OT_H)
769 0 : break;
770 : }
771 0 : } while (i > limit);
772 : }
773 0 : break;
774 :
775 : case BASE_POS_LAST_SINHALA:
776 : {
777 : /* Sinhala base positioning is slightly different from main Indic, in that:
778 : * 1. Its ZWJ behavior is different,
779 : * 2. We don't need to look into the font for consonant positions.
780 : */
781 :
782 0 : if (!has_reph)
783 0 : base = limit;
784 :
785 : /* Find the last base consonant that is not blocked by ZWJ. If there is
786 : * a ZWJ right before a base consonant, that would request a subjoined form. */
787 0 : for (unsigned int i = limit; i < end; i++)
788 0 : if (is_consonant (info[i]))
789 : {
790 0 : if (limit < i && info[i - 1].indic_category() == OT_ZWJ)
791 : break;
792 : else
793 0 : base = i;
794 : }
795 :
796 : /* Mark all subsequent consonants as below. */
797 0 : for (unsigned int i = base + 1; i < end; i++)
798 0 : if (is_consonant (info[i]))
799 0 : info[i].indic_position() = POS_BELOW_C;
800 : }
801 0 : break;
802 :
803 : case BASE_POS_FIRST:
804 : {
805 : /* The first consonant is always the base. */
806 :
807 0 : assert (indic_plan->config->reph_mode == REPH_MODE_VIS_REPHA);
808 0 : assert (!has_reph);
809 :
810 0 : base = start;
811 :
812 : /* Mark all subsequent consonants as below. */
813 0 : for (unsigned int i = base + 1; i < end; i++)
814 0 : if (is_consonant (info[i]))
815 0 : info[i].indic_position() = POS_BELOW_C;
816 : }
817 0 : break;
818 : }
819 :
820 : /* -> If the syllable starts with Ra + Halant (in a script that has Reph)
821 : * and has more than one consonant, Ra is excluded from candidates for
822 : * base consonants.
823 : *
824 : * Only do this for unforced Reph. (ie. not for Ra,H,ZWJ. */
825 0 : if (has_reph && base == start && limit - base <= 2) {
826 : /* Have no other consonant, so Reph is not formed and Ra becomes base. */
827 0 : has_reph = false;
828 : }
829 : }
830 :
831 :
832 : /* 2. Decompose and reorder Matras:
833 : *
834 : * Each matra and any syllable modifier sign in the cluster are moved to the
835 : * appropriate position relative to the consonant(s) in the cluster. The
836 : * shaping engine decomposes two- or three-part matras into their constituent
837 : * parts before any repositioning. Matra characters are classified by which
838 : * consonant in a conjunct they have affinity for and are reordered to the
839 : * following positions:
840 : *
841 : * o Before first half form in the syllable
842 : * o After subjoined consonants
843 : * o After post-form consonant
844 : * o After main consonant (for above marks)
845 : *
846 : * IMPLEMENTATION NOTES:
847 : *
848 : * The normalize() routine has already decomposed matras for us, so we don't
849 : * need to worry about that.
850 : */
851 :
852 :
853 : /* 3. Reorder marks to canonical order:
854 : *
855 : * Adjacent nukta and halant or nukta and vedic sign are always repositioned
856 : * if necessary, so that the nukta is first.
857 : *
858 : * IMPLEMENTATION NOTES:
859 : *
860 : * We don't need to do this: the normalize() routine already did this for us.
861 : */
862 :
863 :
864 : /* Reorder characters */
865 :
866 0 : for (unsigned int i = start; i < base; i++)
867 0 : info[i].indic_position() = MIN (POS_PRE_C, (indic_position_t) info[i].indic_position());
868 :
869 0 : if (base < end)
870 0 : info[base].indic_position() = POS_BASE_C;
871 :
872 : /* Mark final consonants. A final consonant is one appearing after a matra,
873 : * like in Khmer. */
874 0 : for (unsigned int i = base + 1; i < end; i++)
875 0 : if (info[i].indic_category() == OT_M) {
876 0 : for (unsigned int j = i + 1; j < end; j++)
877 0 : if (is_consonant (info[j])) {
878 0 : info[j].indic_position() = POS_FINAL_C;
879 0 : break;
880 : }
881 0 : break;
882 : }
883 :
884 : /* Handle beginning Ra */
885 0 : if (has_reph)
886 0 : info[start].indic_position() = POS_RA_TO_BECOME_REPH;
887 :
888 : /* For old-style Indic script tags, move the first post-base Halant after
889 : * last consonant.
890 : *
891 : * Reports suggest that in some scripts Uniscribe does this only if there
892 : * is *not* a Halant after last consonant already (eg. Kannada), while it
893 : * does it unconditionally in other scripts (eg. Malayalam). We don't
894 : * currently know about other scripts, so we single out Malayalam for now.
895 : *
896 : * Kannada test case:
897 : * U+0C9A,U+0CCD,U+0C9A,U+0CCD
898 : * With some versions of Lohit Kannada.
899 : * https://bugs.freedesktop.org/show_bug.cgi?id=59118
900 : *
901 : * Malayalam test case:
902 : * U+0D38,U+0D4D,U+0D31,U+0D4D,U+0D31,U+0D4D
903 : * With lohit-ttf-20121122/Lohit-Malayalam.ttf
904 : */
905 0 : if (indic_plan->is_old_spec)
906 : {
907 0 : bool disallow_double_halants = buffer->props.script != HB_SCRIPT_MALAYALAM;
908 0 : for (unsigned int i = base + 1; i < end; i++)
909 0 : if (info[i].indic_category() == OT_H)
910 : {
911 : unsigned int j;
912 0 : for (j = end - 1; j > i; j--)
913 0 : if (is_consonant (info[j]) ||
914 0 : (disallow_double_halants && info[j].indic_category() == OT_H))
915 0 : break;
916 0 : if (info[j].indic_category() != OT_H && j > i) {
917 : /* Move Halant to after last consonant. */
918 0 : hb_glyph_info_t t = info[i];
919 0 : memmove (&info[i], &info[i + 1], (j - i) * sizeof (info[0]));
920 0 : info[j] = t;
921 : }
922 0 : break;
923 : }
924 : }
925 :
926 : /* Attach misc marks to previous char to move with them. */
927 : {
928 0 : indic_position_t last_pos = POS_START;
929 0 : for (unsigned int i = start; i < end; i++)
930 : {
931 0 : if ((FLAG_SAFE (info[i].indic_category()) & (JOINER_FLAGS | FLAG (OT_N) | FLAG (OT_RS) | MEDIAL_FLAGS | HALANT_OR_COENG_FLAGS)))
932 : {
933 0 : info[i].indic_position() = last_pos;
934 0 : if (unlikely (info[i].indic_category() == OT_H &&
935 : info[i].indic_position() == POS_PRE_M))
936 : {
937 : /*
938 : * Uniscribe doesn't move the Halant with Left Matra.
939 : * TEST: U+092B,U+093F,U+094DE
940 : * We follow. This is important for the Sinhala
941 : * U+0DDA split matra since it decomposes to U+0DD9,U+0DCA
942 : * where U+0DD9 is a left matra and U+0DCA is the virama.
943 : * We don't want to move the virama with the left matra.
944 : * TEST: U+0D9A,U+0DDA
945 : */
946 0 : for (unsigned int j = i; j > start; j--)
947 0 : if (info[j - 1].indic_position() != POS_PRE_M) {
948 0 : info[i].indic_position() = info[j - 1].indic_position();
949 0 : break;
950 : }
951 : }
952 0 : } else if (info[i].indic_position() != POS_SMVD) {
953 0 : last_pos = (indic_position_t) info[i].indic_position();
954 : }
955 : }
956 : }
957 : /* For post-base consonants let them own anything before them
958 : * since the last consonant or matra. */
959 : {
960 0 : unsigned int last = base;
961 0 : for (unsigned int i = base + 1; i < end; i++)
962 0 : if (is_consonant (info[i]))
963 : {
964 0 : for (unsigned int j = last + 1; j < i; j++)
965 0 : if (info[j].indic_position() < POS_SMVD)
966 0 : info[j].indic_position() = info[i].indic_position();
967 0 : last = i;
968 0 : } else if (info[i].indic_category() == OT_M)
969 0 : last = i;
970 : }
971 :
972 :
973 : {
974 : /* Use syllable() for sort accounting temporarily. */
975 0 : unsigned int syllable = info[start].syllable();
976 0 : for (unsigned int i = start; i < end; i++)
977 0 : info[i].syllable() = i - start;
978 :
979 : /* Sit tight, rock 'n roll! */
980 0 : hb_stable_sort (info + start, end - start, compare_indic_order);
981 : /* Find base again */
982 0 : base = end;
983 0 : for (unsigned int i = start; i < end; i++)
984 0 : if (info[i].indic_position() == POS_BASE_C)
985 : {
986 0 : base = i;
987 0 : break;
988 : }
989 : /* Things are out-of-control for post base positions, they may shuffle
990 : * around like crazy. In old-spec mode, we move halants around, so in
991 : * that case merge all clusters after base. Otherwise, check the sort
992 : * order and merge as needed.
993 : * For pre-base stuff, we handle cluster issues in final reordering.
994 : *
995 : * We could use buffer->sort() for this, if there was no special
996 : * reordering of pre-base stuff happening later...
997 : */
998 0 : if (indic_plan->is_old_spec || end - base > 127)
999 0 : buffer->merge_clusters (base, end);
1000 : else
1001 : {
1002 : /* Note! syllable() is a one-byte field. */
1003 0 : for (unsigned int i = base; i < end; i++)
1004 0 : if (info[i].syllable() != 255)
1005 : {
1006 0 : unsigned int max = i;
1007 0 : unsigned int j = start + info[i].syllable();
1008 0 : while (j != i)
1009 : {
1010 0 : max = MAX (max, j);
1011 0 : unsigned int next = start + info[j].syllable();
1012 0 : info[j].syllable() = 255; /* So we don't process j later again. */
1013 0 : j = next;
1014 : }
1015 0 : if (i != max)
1016 0 : buffer->merge_clusters (i, max + 1);
1017 : }
1018 : }
1019 :
1020 : /* Put syllable back in. */
1021 0 : for (unsigned int i = start; i < end; i++)
1022 0 : info[i].syllable() = syllable;
1023 : }
1024 :
1025 : /* Setup masks now */
1026 :
1027 : {
1028 : hb_mask_t mask;
1029 :
1030 : /* Reph */
1031 0 : for (unsigned int i = start; i < end && info[i].indic_position() == POS_RA_TO_BECOME_REPH; i++)
1032 0 : info[i].mask |= indic_plan->mask_array[RPHF];
1033 :
1034 : /* Pre-base */
1035 0 : mask = indic_plan->mask_array[HALF];
1036 0 : if (!indic_plan->is_old_spec &&
1037 0 : indic_plan->config->blwf_mode == BLWF_MODE_PRE_AND_POST)
1038 0 : mask |= indic_plan->mask_array[BLWF];
1039 0 : for (unsigned int i = start; i < base; i++)
1040 0 : info[i].mask |= mask;
1041 : /* Base */
1042 0 : mask = 0;
1043 0 : if (base < end)
1044 0 : info[base].mask |= mask;
1045 : /* Post-base */
1046 0 : mask = indic_plan->mask_array[BLWF] | indic_plan->mask_array[ABVF] | indic_plan->mask_array[PSTF];
1047 0 : for (unsigned int i = base + 1; i < end; i++)
1048 0 : info[i].mask |= mask;
1049 : }
1050 :
1051 0 : if (indic_plan->is_old_spec &&
1052 0 : buffer->props.script == HB_SCRIPT_DEVANAGARI)
1053 : {
1054 : /* Old-spec eye-lash Ra needs special handling. From the
1055 : * spec:
1056 : *
1057 : * "The feature 'below-base form' is applied to consonants
1058 : * having below-base forms and following the base consonant.
1059 : * The exception is vattu, which may appear below half forms
1060 : * as well as below the base glyph. The feature 'below-base
1061 : * form' will be applied to all such occurrences of Ra as well."
1062 : *
1063 : * Test case: U+0924,U+094D,U+0930,U+094d,U+0915
1064 : * with Sanskrit 2003 font.
1065 : *
1066 : * However, note that Ra,Halant,ZWJ is the correct way to
1067 : * request eyelash form of Ra, so we wouldbn't inhibit it
1068 : * in that sequence.
1069 : *
1070 : * Test case: U+0924,U+094D,U+0930,U+094d,U+200D,U+0915
1071 : */
1072 0 : for (unsigned int i = start; i + 1 < base; i++)
1073 0 : if (info[i ].indic_category() == OT_Ra &&
1074 0 : info[i+1].indic_category() == OT_H &&
1075 0 : (i + 2 == base ||
1076 0 : info[i+2].indic_category() != OT_ZWJ))
1077 : {
1078 0 : info[i ].mask |= indic_plan->mask_array[BLWF];
1079 0 : info[i+1].mask |= indic_plan->mask_array[BLWF];
1080 : }
1081 : }
1082 :
1083 0 : unsigned int pref_len = 2;
1084 0 : if (indic_plan->mask_array[PREF] && base + pref_len < end)
1085 : {
1086 : /* Find a Halant,Ra sequence and mark it for pre-base reordering processing. */
1087 0 : for (unsigned int i = base + 1; i + pref_len - 1 < end; i++) {
1088 : hb_codepoint_t glyphs[2];
1089 0 : for (unsigned int j = 0; j < pref_len; j++)
1090 0 : glyphs[j] = info[i + j].codepoint;
1091 0 : if (indic_plan->pref.would_substitute (glyphs, pref_len, face))
1092 : {
1093 0 : for (unsigned int j = 0; j < pref_len; j++)
1094 0 : info[i++].mask |= indic_plan->mask_array[PREF];
1095 :
1096 : /* Mark the subsequent stuff with 'cfar'. Used in Khmer.
1097 : * Read the feature spec.
1098 : * This allows distinguishing the following cases with MS Khmer fonts:
1099 : * U+1784,U+17D2,U+179A,U+17D2,U+1782
1100 : * U+1784,U+17D2,U+1782,U+17D2,U+179A
1101 : */
1102 0 : if (indic_plan->mask_array[CFAR])
1103 0 : for (; i < end; i++)
1104 0 : info[i].mask |= indic_plan->mask_array[CFAR];
1105 :
1106 0 : break;
1107 : }
1108 : }
1109 : }
1110 :
1111 : /* Apply ZWJ/ZWNJ effects */
1112 0 : for (unsigned int i = start + 1; i < end; i++)
1113 0 : if (is_joiner (info[i])) {
1114 0 : bool non_joiner = info[i].indic_category() == OT_ZWNJ;
1115 0 : unsigned int j = i;
1116 :
1117 0 : do {
1118 0 : j--;
1119 :
1120 : /* ZWJ/ZWNJ should disable CJCT. They do that by simply
1121 : * being there, since we don't skip them for the CJCT
1122 : * feature (ie. F_MANUAL_ZWJ) */
1123 :
1124 : /* A ZWNJ disables HALF. */
1125 0 : if (non_joiner)
1126 0 : info[j].mask &= ~indic_plan->mask_array[HALF];
1127 :
1128 0 : } while (j > start && !is_consonant (info[j]));
1129 : }
1130 0 : }
1131 :
1132 : static void
1133 0 : initial_reordering_standalone_cluster (const hb_ot_shape_plan_t *plan,
1134 : hb_face_t *face,
1135 : hb_buffer_t *buffer,
1136 : unsigned int start, unsigned int end)
1137 : {
1138 : /* We treat placeholder/dotted-circle as if they are consonants, so we
1139 : * should just chain. Only if not in compatibility mode that is... */
1140 :
1141 0 : if (hb_options ().uniscribe_bug_compatible)
1142 : {
1143 : /* For dotted-circle, this is what Uniscribe does:
1144 : * If dotted-circle is the last glyph, it just does nothing.
1145 : * Ie. It doesn't form Reph. */
1146 0 : if (buffer->info[end - 1].indic_category() == OT_DOTTEDCIRCLE)
1147 0 : return;
1148 : }
1149 :
1150 0 : initial_reordering_consonant_syllable (plan, face, buffer, start, end);
1151 : }
1152 :
1153 : static void
1154 0 : initial_reordering_syllable (const hb_ot_shape_plan_t *plan,
1155 : hb_face_t *face,
1156 : hb_buffer_t *buffer,
1157 : unsigned int start, unsigned int end)
1158 : {
1159 0 : syllable_type_t syllable_type = (syllable_type_t) (buffer->info[start].syllable() & 0x0F);
1160 0 : switch (syllable_type)
1161 : {
1162 : case vowel_syllable: /* We made the vowels look like consonants. So let's call the consonant logic! */
1163 : case consonant_syllable:
1164 0 : initial_reordering_consonant_syllable (plan, face, buffer, start, end);
1165 0 : break;
1166 :
1167 : case broken_cluster: /* We already inserted dotted-circles, so just call the standalone_cluster. */
1168 : case standalone_cluster:
1169 0 : initial_reordering_standalone_cluster (plan, face, buffer, start, end);
1170 0 : break;
1171 :
1172 : case symbol_cluster:
1173 : case non_indic_cluster:
1174 0 : break;
1175 : }
1176 0 : }
1177 :
1178 : static inline void
1179 0 : insert_dotted_circles (const hb_ot_shape_plan_t *plan HB_UNUSED,
1180 : hb_font_t *font,
1181 : hb_buffer_t *buffer)
1182 : {
1183 : /* Note: This loop is extra overhead, but should not be measurable. */
1184 0 : bool has_broken_syllables = false;
1185 0 : unsigned int count = buffer->len;
1186 0 : hb_glyph_info_t *info = buffer->info;
1187 0 : for (unsigned int i = 0; i < count; i++)
1188 0 : if ((info[i].syllable() & 0x0F) == broken_cluster)
1189 : {
1190 0 : has_broken_syllables = true;
1191 0 : break;
1192 : }
1193 0 : if (likely (!has_broken_syllables))
1194 0 : return;
1195 :
1196 :
1197 : hb_codepoint_t dottedcircle_glyph;
1198 0 : if (!font->get_nominal_glyph (0x25CCu, &dottedcircle_glyph))
1199 0 : return;
1200 :
1201 0 : hb_glyph_info_t dottedcircle = {0};
1202 0 : dottedcircle.codepoint = 0x25CCu;
1203 0 : set_indic_properties (dottedcircle);
1204 0 : dottedcircle.codepoint = dottedcircle_glyph;
1205 :
1206 0 : buffer->clear_output ();
1207 :
1208 0 : buffer->idx = 0;
1209 0 : unsigned int last_syllable = 0;
1210 0 : while (buffer->idx < buffer->len && !buffer->in_error)
1211 : {
1212 0 : unsigned int syllable = buffer->cur().syllable();
1213 0 : syllable_type_t syllable_type = (syllable_type_t) (syllable & 0x0F);
1214 0 : if (unlikely (last_syllable != syllable && syllable_type == broken_cluster))
1215 : {
1216 0 : last_syllable = syllable;
1217 :
1218 0 : hb_glyph_info_t ginfo = dottedcircle;
1219 0 : ginfo.cluster = buffer->cur().cluster;
1220 0 : ginfo.mask = buffer->cur().mask;
1221 0 : ginfo.syllable() = buffer->cur().syllable();
1222 : /* TODO Set glyph_props? */
1223 :
1224 : /* Insert dottedcircle after possible Repha. */
1225 0 : while (buffer->idx < buffer->len && !buffer->in_error &&
1226 0 : last_syllable == buffer->cur().syllable() &&
1227 0 : buffer->cur().indic_category() == OT_Repha)
1228 0 : buffer->next_glyph ();
1229 :
1230 0 : buffer->output_info (ginfo);
1231 : }
1232 : else
1233 0 : buffer->next_glyph ();
1234 : }
1235 :
1236 0 : buffer->swap_buffers ();
1237 : }
1238 :
1239 : static void
1240 0 : initial_reordering (const hb_ot_shape_plan_t *plan,
1241 : hb_font_t *font,
1242 : hb_buffer_t *buffer)
1243 : {
1244 0 : update_consonant_positions (plan, font, buffer);
1245 0 : insert_dotted_circles (plan, font, buffer);
1246 :
1247 0 : foreach_syllable (buffer, start, end)
1248 0 : initial_reordering_syllable (plan, font->face, buffer, start, end);
1249 0 : }
1250 :
1251 : static void
1252 0 : final_reordering_syllable (const hb_ot_shape_plan_t *plan,
1253 : hb_buffer_t *buffer,
1254 : unsigned int start, unsigned int end)
1255 : {
1256 0 : const indic_shape_plan_t *indic_plan = (const indic_shape_plan_t *) plan->data;
1257 0 : hb_glyph_info_t *info = buffer->info;
1258 :
1259 :
1260 : /* This function relies heavily on halant glyphs. Lots of ligation
1261 : * and possibly multiplication substitutions happened prior to this
1262 : * phase, and that might have messed up our properties. Recover
1263 : * from a particular case of that where we're fairly sure that a
1264 : * class of OT_H is desired but has been lost. */
1265 0 : if (indic_plan->virama_glyph)
1266 : {
1267 0 : unsigned int virama_glyph = indic_plan->virama_glyph;
1268 0 : for (unsigned int i = start; i < end; i++)
1269 0 : if (info[i].codepoint == virama_glyph &&
1270 0 : _hb_glyph_info_ligated (&info[i]) &&
1271 0 : _hb_glyph_info_multiplied (&info[i]))
1272 : {
1273 : /* This will make sure that this glyph passes is_halant_or_coeng() test. */
1274 0 : info[i].indic_category() = OT_H;
1275 0 : _hb_glyph_info_clear_ligated_and_multiplied (&info[i]);
1276 : }
1277 : }
1278 :
1279 :
1280 : /* 4. Final reordering:
1281 : *
1282 : * After the localized forms and basic shaping forms GSUB features have been
1283 : * applied (see below), the shaping engine performs some final glyph
1284 : * reordering before applying all the remaining font features to the entire
1285 : * cluster.
1286 : */
1287 :
1288 0 : bool try_pref = !!indic_plan->mask_array[PREF];
1289 :
1290 : /* Find base again */
1291 : unsigned int base;
1292 0 : for (base = start; base < end; base++)
1293 0 : if (info[base].indic_position() >= POS_BASE_C)
1294 : {
1295 0 : if (try_pref && base + 1 < end)
1296 : {
1297 0 : for (unsigned int i = base + 1; i < end; i++)
1298 0 : if ((info[i].mask & indic_plan->mask_array[PREF]) != 0)
1299 : {
1300 0 : if (!(_hb_glyph_info_substituted (&info[i]) &&
1301 0 : _hb_glyph_info_ligated_and_didnt_multiply (&info[i])))
1302 : {
1303 : /* Ok, this was a 'pref' candidate but didn't form any.
1304 : * Base is around here... */
1305 0 : base = i;
1306 0 : while (base < end && is_halant_or_coeng (info[base]))
1307 0 : base++;
1308 0 : info[base].indic_position() = POS_BASE_C;
1309 :
1310 0 : try_pref = false;
1311 : }
1312 0 : break;
1313 : }
1314 : }
1315 : /* For Malayalam, skip over unformed below- (but NOT post-) forms. */
1316 0 : if (buffer->props.script == HB_SCRIPT_MALAYALAM)
1317 : {
1318 0 : for (unsigned int i = base + 1; i < end; i++)
1319 : {
1320 0 : while (i < end && is_joiner (info[i]))
1321 0 : i++;
1322 0 : if (i == end || !is_halant_or_coeng (info[i]))
1323 0 : break;
1324 0 : i++; /* Skip halant. */
1325 0 : while (i < end && is_joiner (info[i]))
1326 0 : i++;
1327 0 : if (i < end && is_consonant (info[i]) && info[i].indic_position() == POS_BELOW_C)
1328 : {
1329 0 : base = i;
1330 0 : info[base].indic_position() = POS_BASE_C;
1331 : }
1332 : }
1333 : }
1334 :
1335 0 : if (start < base && info[base].indic_position() > POS_BASE_C)
1336 0 : base--;
1337 0 : break;
1338 : }
1339 0 : if (base == end && start < base &&
1340 0 : is_one_of (info[base - 1], FLAG (OT_ZWJ)))
1341 0 : base--;
1342 0 : if (base < end)
1343 0 : while (start < base &&
1344 0 : is_one_of (info[base], (FLAG (OT_N) | HALANT_OR_COENG_FLAGS)))
1345 0 : base--;
1346 :
1347 :
1348 : /* o Reorder matras:
1349 : *
1350 : * If a pre-base matra character had been reordered before applying basic
1351 : * features, the glyph can be moved closer to the main consonant based on
1352 : * whether half-forms had been formed. Actual position for the matra is
1353 : * defined as “after last standalone halant glyph, after initial matra
1354 : * position and before the main consonant”. If ZWJ or ZWNJ follow this
1355 : * halant, position is moved after it.
1356 : */
1357 :
1358 0 : if (start + 1 < end && start < base) /* Otherwise there can't be any pre-base matra characters. */
1359 : {
1360 : /* If we lost track of base, alas, position before last thingy. */
1361 0 : unsigned int new_pos = base == end ? base - 2 : base - 1;
1362 :
1363 : /* Malayalam / Tamil do not have "half" forms or explicit virama forms.
1364 : * The glyphs formed by 'half' are Chillus or ligated explicit viramas.
1365 : * We want to position matra after them.
1366 : */
1367 0 : if (buffer->props.script != HB_SCRIPT_MALAYALAM && buffer->props.script != HB_SCRIPT_TAMIL)
1368 : {
1369 0 : while (new_pos > start &&
1370 0 : !(is_one_of (info[new_pos], (FLAG (OT_M) | HALANT_OR_COENG_FLAGS))))
1371 0 : new_pos--;
1372 :
1373 : /* If we found no Halant we are done.
1374 : * Otherwise only proceed if the Halant does
1375 : * not belong to the Matra itself! */
1376 0 : if (is_halant_or_coeng (info[new_pos]) &&
1377 0 : info[new_pos].indic_position() != POS_PRE_M)
1378 : {
1379 : /* -> If ZWJ or ZWNJ follow this halant, position is moved after it. */
1380 0 : if (new_pos + 1 < end && is_joiner (info[new_pos + 1]))
1381 0 : new_pos++;
1382 : }
1383 : else
1384 0 : new_pos = start; /* No move. */
1385 : }
1386 :
1387 0 : if (start < new_pos && info[new_pos].indic_position () != POS_PRE_M)
1388 : {
1389 : /* Now go see if there's actually any matras... */
1390 0 : for (unsigned int i = new_pos; i > start; i--)
1391 0 : if (info[i - 1].indic_position () == POS_PRE_M)
1392 : {
1393 0 : unsigned int old_pos = i - 1;
1394 0 : if (old_pos < base && base <= new_pos) /* Shouldn't actually happen. */
1395 0 : base--;
1396 :
1397 0 : hb_glyph_info_t tmp = info[old_pos];
1398 0 : memmove (&info[old_pos], &info[old_pos + 1], (new_pos - old_pos) * sizeof (info[0]));
1399 0 : info[new_pos] = tmp;
1400 :
1401 : /* Note: this merge_clusters() is intentionally *after* the reordering.
1402 : * Indic matra reordering is special and tricky... */
1403 0 : buffer->merge_clusters (new_pos, MIN (end, base + 1));
1404 :
1405 0 : new_pos--;
1406 0 : }
1407 : } else {
1408 0 : for (unsigned int i = start; i < base; i++)
1409 0 : if (info[i].indic_position () == POS_PRE_M) {
1410 0 : buffer->merge_clusters (i, MIN (end, base + 1));
1411 0 : break;
1412 : }
1413 : }
1414 : }
1415 :
1416 :
1417 : /* o Reorder reph:
1418 : *
1419 : * Reph’s original position is always at the beginning of the syllable,
1420 : * (i.e. it is not reordered at the character reordering stage). However,
1421 : * it will be reordered according to the basic-forms shaping results.
1422 : * Possible positions for reph, depending on the script, are; after main,
1423 : * before post-base consonant forms, and after post-base consonant forms.
1424 : */
1425 :
1426 : /* Two cases:
1427 : *
1428 : * - If repha is encoded as a sequence of characters (Ra,H or Ra,H,ZWJ), then
1429 : * we should only move it if the sequence ligated to the repha form.
1430 : *
1431 : * - If repha is encoded separately and in the logical position, we should only
1432 : * move it if it did NOT ligate. If it ligated, it's probably the font trying
1433 : * to make it work without the reordering.
1434 : */
1435 0 : if (start + 1 < end &&
1436 0 : info[start].indic_position() == POS_RA_TO_BECOME_REPH &&
1437 0 : ((info[start].indic_category() == OT_Repha) ^
1438 0 : _hb_glyph_info_ligated_and_didnt_multiply (&info[start])))
1439 : {
1440 : unsigned int new_reph_pos;
1441 0 : reph_position_t reph_pos = indic_plan->config->reph_pos;
1442 :
1443 0 : assert (reph_pos != REPH_POS_DONT_CARE);
1444 :
1445 : /* 1. If reph should be positioned after post-base consonant forms,
1446 : * proceed to step 5.
1447 : */
1448 0 : if (reph_pos == REPH_POS_AFTER_POST)
1449 : {
1450 0 : goto reph_step_5;
1451 : }
1452 :
1453 : /* 2. If the reph repositioning class is not after post-base: target
1454 : * position is after the first explicit halant glyph between the
1455 : * first post-reph consonant and last main consonant. If ZWJ or ZWNJ
1456 : * are following this halant, position is moved after it. If such
1457 : * position is found, this is the target position. Otherwise,
1458 : * proceed to the next step.
1459 : *
1460 : * Note: in old-implementation fonts, where classifications were
1461 : * fixed in shaping engine, there was no case where reph position
1462 : * will be found on this step.
1463 : */
1464 : {
1465 0 : new_reph_pos = start + 1;
1466 0 : while (new_reph_pos < base && !is_halant_or_coeng (info[new_reph_pos]))
1467 0 : new_reph_pos++;
1468 :
1469 0 : if (new_reph_pos < base && is_halant_or_coeng (info[new_reph_pos]))
1470 : {
1471 : /* ->If ZWJ or ZWNJ are following this halant, position is moved after it. */
1472 0 : if (new_reph_pos + 1 < base && is_joiner (info[new_reph_pos + 1]))
1473 0 : new_reph_pos++;
1474 0 : goto reph_move;
1475 : }
1476 : }
1477 :
1478 : /* 3. If reph should be repositioned after the main consonant: find the
1479 : * first consonant not ligated with main, or find the first
1480 : * consonant that is not a potential pre-base reordering Ra.
1481 : */
1482 0 : if (reph_pos == REPH_POS_AFTER_MAIN)
1483 : {
1484 0 : new_reph_pos = base;
1485 0 : while (new_reph_pos + 1 < end && info[new_reph_pos + 1].indic_position() <= POS_AFTER_MAIN)
1486 0 : new_reph_pos++;
1487 0 : if (new_reph_pos < end)
1488 0 : goto reph_move;
1489 : }
1490 :
1491 : /* 4. If reph should be positioned before post-base consonant, find
1492 : * first post-base classified consonant not ligated with main. If no
1493 : * consonant is found, the target position should be before the
1494 : * first matra, syllable modifier sign or vedic sign.
1495 : */
1496 : /* This is our take on what step 4 is trying to say (and failing, BADLY). */
1497 0 : if (reph_pos == REPH_POS_AFTER_SUB)
1498 : {
1499 0 : new_reph_pos = base;
1500 0 : while (new_reph_pos + 1 < end &&
1501 0 : !( FLAG_SAFE (info[new_reph_pos + 1].indic_position()) & (FLAG (POS_POST_C) | FLAG (POS_AFTER_POST) | FLAG (POS_SMVD))))
1502 0 : new_reph_pos++;
1503 0 : if (new_reph_pos < end)
1504 0 : goto reph_move;
1505 : }
1506 :
1507 : /* 5. If no consonant is found in steps 3 or 4, move reph to a position
1508 : * immediately before the first post-base matra, syllable modifier
1509 : * sign or vedic sign that has a reordering class after the intended
1510 : * reph position. For example, if the reordering position for reph
1511 : * is post-main, it will skip above-base matras that also have a
1512 : * post-main position.
1513 : */
1514 : reph_step_5:
1515 : {
1516 : /* Copied from step 2. */
1517 0 : new_reph_pos = start + 1;
1518 0 : while (new_reph_pos < base && !is_halant_or_coeng (info[new_reph_pos]))
1519 0 : new_reph_pos++;
1520 :
1521 0 : if (new_reph_pos < base && is_halant_or_coeng (info[new_reph_pos]))
1522 : {
1523 : /* ->If ZWJ or ZWNJ are following this halant, position is moved after it. */
1524 0 : if (new_reph_pos + 1 < base && is_joiner (info[new_reph_pos + 1]))
1525 0 : new_reph_pos++;
1526 0 : goto reph_move;
1527 : }
1528 : }
1529 :
1530 : /* 6. Otherwise, reorder reph to the end of the syllable.
1531 : */
1532 : {
1533 0 : new_reph_pos = end - 1;
1534 0 : while (new_reph_pos > start && info[new_reph_pos].indic_position() == POS_SMVD)
1535 0 : new_reph_pos--;
1536 :
1537 : /*
1538 : * If the Reph is to be ending up after a Matra,Halant sequence,
1539 : * position it before that Halant so it can interact with the Matra.
1540 : * However, if it's a plain Consonant,Halant we shouldn't do that.
1541 : * Uniscribe doesn't do this.
1542 : * TEST: U+0930,U+094D,U+0915,U+094B,U+094D
1543 : */
1544 0 : if (!hb_options ().uniscribe_bug_compatible &&
1545 0 : unlikely (is_halant_or_coeng (info[new_reph_pos]))) {
1546 0 : for (unsigned int i = base + 1; i < new_reph_pos; i++)
1547 0 : if (info[i].indic_category() == OT_M) {
1548 : /* Ok, got it. */
1549 0 : new_reph_pos--;
1550 : }
1551 : }
1552 0 : goto reph_move;
1553 : }
1554 :
1555 : reph_move:
1556 : {
1557 : /* Move */
1558 0 : buffer->merge_clusters (start, new_reph_pos + 1);
1559 0 : hb_glyph_info_t reph = info[start];
1560 0 : memmove (&info[start], &info[start + 1], (new_reph_pos - start) * sizeof (info[0]));
1561 0 : info[new_reph_pos] = reph;
1562 :
1563 0 : if (start < base && base <= new_reph_pos)
1564 0 : base--;
1565 : }
1566 : }
1567 :
1568 :
1569 : /* o Reorder pre-base reordering consonants:
1570 : *
1571 : * If a pre-base reordering consonant is found, reorder it according to
1572 : * the following rules:
1573 : */
1574 :
1575 0 : if (try_pref && base + 1 < end) /* Otherwise there can't be any pre-base reordering Ra. */
1576 : {
1577 0 : for (unsigned int i = base + 1; i < end; i++)
1578 0 : if ((info[i].mask & indic_plan->mask_array[PREF]) != 0)
1579 : {
1580 : /* 1. Only reorder a glyph produced by substitution during application
1581 : * of the <pref> feature. (Note that a font may shape a Ra consonant with
1582 : * the feature generally but block it in certain contexts.)
1583 : */
1584 : /* Note: We just check that something got substituted. We don't check that
1585 : * the <pref> feature actually did it...
1586 : *
1587 : * Reorder pref only if it ligated. */
1588 0 : if (_hb_glyph_info_ligated_and_didnt_multiply (&info[i]))
1589 : {
1590 : /*
1591 : * 2. Try to find a target position the same way as for pre-base matra.
1592 : * If it is found, reorder pre-base consonant glyph.
1593 : *
1594 : * 3. If position is not found, reorder immediately before main
1595 : * consonant.
1596 : */
1597 :
1598 0 : unsigned int new_pos = base;
1599 : /* Malayalam / Tamil do not have "half" forms or explicit virama forms.
1600 : * The glyphs formed by 'half' are Chillus or ligated explicit viramas.
1601 : * We want to position matra after them.
1602 : */
1603 0 : if (buffer->props.script != HB_SCRIPT_MALAYALAM && buffer->props.script != HB_SCRIPT_TAMIL)
1604 : {
1605 0 : while (new_pos > start &&
1606 0 : !(is_one_of (info[new_pos - 1], FLAG(OT_M) | HALANT_OR_COENG_FLAGS)))
1607 0 : new_pos--;
1608 :
1609 : /* In Khmer coeng model, a H,Ra can go *after* matras. If it goes after a
1610 : * split matra, it should be reordered to *before* the left part of such matra. */
1611 0 : if (new_pos > start && info[new_pos - 1].indic_category() == OT_M)
1612 : {
1613 0 : unsigned int old_pos = i;
1614 0 : for (unsigned int j = base + 1; j < old_pos; j++)
1615 0 : if (info[j].indic_category() == OT_M)
1616 : {
1617 0 : new_pos--;
1618 0 : break;
1619 : }
1620 : }
1621 : }
1622 :
1623 0 : if (new_pos > start && is_halant_or_coeng (info[new_pos - 1]))
1624 : {
1625 : /* -> If ZWJ or ZWNJ follow this halant, position is moved after it. */
1626 0 : if (new_pos < end && is_joiner (info[new_pos]))
1627 0 : new_pos++;
1628 : }
1629 :
1630 : {
1631 0 : unsigned int old_pos = i;
1632 :
1633 0 : buffer->merge_clusters (new_pos, old_pos + 1);
1634 0 : hb_glyph_info_t tmp = info[old_pos];
1635 0 : memmove (&info[new_pos + 1], &info[new_pos], (old_pos - new_pos) * sizeof (info[0]));
1636 0 : info[new_pos] = tmp;
1637 :
1638 0 : if (new_pos <= base && base < old_pos)
1639 0 : base++;
1640 : }
1641 : }
1642 :
1643 0 : break;
1644 : }
1645 : }
1646 :
1647 :
1648 : /* Apply 'init' to the Left Matra if it's a word start. */
1649 0 : if (info[start].indic_position () == POS_PRE_M &&
1650 0 : (!start ||
1651 0 : !(FLAG_SAFE (_hb_glyph_info_get_general_category (&info[start - 1])) &
1652 : FLAG_RANGE (HB_UNICODE_GENERAL_CATEGORY_FORMAT, HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK))))
1653 0 : info[start].mask |= indic_plan->mask_array[INIT];
1654 :
1655 :
1656 : /*
1657 : * Finish off the clusters and go home!
1658 : */
1659 0 : if (hb_options ().uniscribe_bug_compatible)
1660 : {
1661 0 : switch ((hb_tag_t) plan->props.script)
1662 : {
1663 : case HB_SCRIPT_TAMIL:
1664 : case HB_SCRIPT_SINHALA:
1665 0 : break;
1666 :
1667 : default:
1668 : /* Uniscribe merges the entire cluster... Except for Tamil & Sinhala.
1669 : * This means, half forms are submerged into the main consonants cluster.
1670 : * This is unnecessary, and makes cursor positioning harder, but that's what
1671 : * Uniscribe does. */
1672 0 : buffer->merge_clusters (start, end);
1673 0 : break;
1674 : }
1675 : }
1676 0 : }
1677 :
1678 :
1679 : static void
1680 0 : final_reordering (const hb_ot_shape_plan_t *plan,
1681 : hb_font_t *font HB_UNUSED,
1682 : hb_buffer_t *buffer)
1683 : {
1684 0 : unsigned int count = buffer->len;
1685 0 : if (unlikely (!count)) return;
1686 :
1687 0 : foreach_syllable (buffer, start, end)
1688 0 : final_reordering_syllable (plan, buffer, start, end);
1689 :
1690 0 : HB_BUFFER_DEALLOCATE_VAR (buffer, indic_category);
1691 0 : HB_BUFFER_DEALLOCATE_VAR (buffer, indic_position);
1692 : }
1693 :
1694 :
1695 : static void
1696 0 : clear_syllables (const hb_ot_shape_plan_t *plan HB_UNUSED,
1697 : hb_font_t *font HB_UNUSED,
1698 : hb_buffer_t *buffer)
1699 : {
1700 0 : hb_glyph_info_t *info = buffer->info;
1701 0 : unsigned int count = buffer->len;
1702 0 : for (unsigned int i = 0; i < count; i++)
1703 0 : info[i].syllable() = 0;
1704 0 : }
1705 :
1706 :
1707 : static bool
1708 0 : decompose_indic (const hb_ot_shape_normalize_context_t *c,
1709 : hb_codepoint_t ab,
1710 : hb_codepoint_t *a,
1711 : hb_codepoint_t *b)
1712 : {
1713 0 : switch (ab)
1714 : {
1715 : /* Don't decompose these. */
1716 0 : case 0x0931u : return false; /* DEVANAGARI LETTER RRA */
1717 0 : case 0x0B94u : return false; /* TAMIL LETTER AU */
1718 :
1719 :
1720 : /*
1721 : * Decompose split matras that don't have Unicode decompositions.
1722 : */
1723 :
1724 : /* Khmer */
1725 0 : case 0x17BEu : *a = 0x17C1u; *b= 0x17BEu; return true;
1726 0 : case 0x17BFu : *a = 0x17C1u; *b= 0x17BFu; return true;
1727 0 : case 0x17C0u : *a = 0x17C1u; *b= 0x17C0u; return true;
1728 0 : case 0x17C4u : *a = 0x17C1u; *b= 0x17C4u; return true;
1729 0 : case 0x17C5u : *a = 0x17C1u; *b= 0x17C5u; return true;
1730 :
1731 : #if 0
1732 : /* Gujarati */
1733 : /* This one has no decomposition in Unicode, but needs no decomposition either. */
1734 : /* case 0x0AC9u : return false; */
1735 :
1736 : /* Oriya */
1737 : case 0x0B57u : *a = no decomp, -> RIGHT; return true;
1738 : #endif
1739 : }
1740 :
1741 0 : if ((ab == 0x0DDAu || hb_in_range (ab, 0x0DDCu, 0x0DDEu)))
1742 : {
1743 : /*
1744 : * Sinhala split matras... Let the fun begin.
1745 : *
1746 : * These four characters have Unicode decompositions. However, Uniscribe
1747 : * decomposes them "Khmer-style", that is, it uses the character itself to
1748 : * get the second half. The first half of all four decompositions is always
1749 : * U+0DD9.
1750 : *
1751 : * Now, there are buggy fonts, namely, the widely used lklug.ttf, that are
1752 : * broken with Uniscribe. But we need to support them. As such, we only
1753 : * do the Uniscribe-style decomposition if the character is transformed into
1754 : * its "sec.half" form by the 'pstf' feature. Otherwise, we fall back to
1755 : * Unicode decomposition.
1756 : *
1757 : * Note that we can't unconditionally use Unicode decomposition. That would
1758 : * break some other fonts, that are designed to work with Uniscribe, and
1759 : * don't have positioning features for the Unicode-style decomposition.
1760 : *
1761 : * Argh...
1762 : *
1763 : * The Uniscribe behavior is now documented in the newly published Sinhala
1764 : * spec in 2012:
1765 : *
1766 : * http://www.microsoft.com/typography/OpenTypeDev/sinhala/intro.htm#shaping
1767 : */
1768 :
1769 0 : const indic_shape_plan_t *indic_plan = (const indic_shape_plan_t *) c->plan->data;
1770 :
1771 : hb_codepoint_t glyph;
1772 :
1773 0 : if (hb_options ().uniscribe_bug_compatible ||
1774 0 : (c->font->get_nominal_glyph (ab, &glyph) &&
1775 0 : indic_plan->pstf.would_substitute (&glyph, 1, c->font->face)))
1776 : {
1777 : /* Ok, safe to use Uniscribe-style decomposition. */
1778 0 : *a = 0x0DD9u;
1779 0 : *b = ab;
1780 0 : return true;
1781 : }
1782 : }
1783 :
1784 0 : return (bool) c->unicode->decompose (ab, a, b);
1785 : }
1786 :
1787 : static bool
1788 0 : compose_indic (const hb_ot_shape_normalize_context_t *c,
1789 : hb_codepoint_t a,
1790 : hb_codepoint_t b,
1791 : hb_codepoint_t *ab)
1792 : {
1793 : /* Avoid recomposing split matras. */
1794 0 : if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (c->unicode->general_category (a)))
1795 0 : return false;
1796 :
1797 : /* Composition-exclusion exceptions that we want to recompose. */
1798 0 : if (a == 0x09AFu && b == 0x09BCu) { *ab = 0x09DFu; return true; }
1799 :
1800 0 : return (bool) c->unicode->compose (a, b, ab);
1801 : }
1802 :
1803 :
1804 : const hb_ot_complex_shaper_t _hb_ot_complex_shaper_indic =
1805 : {
1806 : "indic",
1807 : collect_features_indic,
1808 : override_features_indic,
1809 : data_create_indic,
1810 : data_destroy_indic,
1811 : NULL, /* preprocess_text */
1812 : NULL, /* postprocess_glyphs */
1813 : HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT,
1814 : decompose_indic,
1815 : compose_indic,
1816 : setup_masks_indic,
1817 : NULL, /* disable_otl */
1818 : HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE,
1819 : false, /* fallback_position */
1820 : };
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