1 | /* |
2 | * Copyright © 2011,2012,2013 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.hh" |
28 | |
29 | #ifndef HB_NO_OT_SHAPE |
30 | |
31 | #include "hb-ot-shaper-myanmar-machine.hh" |
32 | #include "hb-ot-shaper-indic.hh" |
33 | #include "hb-ot-layout.hh" |
34 | |
35 | |
36 | /* |
37 | * Myanmar shaper. |
38 | */ |
39 | |
40 | |
41 | static const hb_tag_t |
42 | myanmar_basic_features[] = |
43 | { |
44 | /* |
45 | * Basic features. |
46 | * These features are applied in order, one at a time, after reordering, |
47 | * constrained to the syllable. |
48 | */ |
49 | HB_TAG('r','p','h','f'), |
50 | HB_TAG('p','r','e','f'), |
51 | HB_TAG('b','l','w','f'), |
52 | HB_TAG('p','s','t','f'), |
53 | }; |
54 | static const hb_tag_t |
55 | myanmar_other_features[] = |
56 | { |
57 | /* |
58 | * Other features. |
59 | * These features are applied all at once, after clearing syllables. |
60 | */ |
61 | HB_TAG('p','r','e','s'), |
62 | HB_TAG('a','b','v','s'), |
63 | HB_TAG('b','l','w','s'), |
64 | HB_TAG('p','s','t','s'), |
65 | }; |
66 | |
67 | static inline void |
68 | set_myanmar_properties (hb_glyph_info_t &info) |
69 | { |
70 | hb_codepoint_t u = info.codepoint; |
71 | unsigned int type = hb_indic_get_categories (u); |
72 | |
73 | info.myanmar_category() = (myanmar_category_t) (type & 0xFFu); |
74 | } |
75 | |
76 | |
77 | static inline bool |
78 | is_one_of_myanmar (const hb_glyph_info_t &info, unsigned int flags) |
79 | { |
80 | /* If it ligated, all bets are off. */ |
81 | if (_hb_glyph_info_ligated (&info)) return false; |
82 | return !!(FLAG_UNSAFE (info.myanmar_category()) & flags); |
83 | } |
84 | |
85 | /* Note: |
86 | * |
87 | * We treat Vowels and placeholders as if they were consonants. This is safe because Vowels |
88 | * cannot happen in a consonant syllable. The plus side however is, we can call the |
89 | * consonant syllable logic from the vowel syllable function and get it all right! |
90 | * |
91 | * Keep in sync with consonant_categories in the generator. */ |
92 | #define CONSONANT_FLAGS_MYANMAR (FLAG (M_Cat(C)) | FLAG (M_Cat(CS)) | FLAG (M_Cat(Ra)) | /* FLAG (M_Cat(CM)) | */ FLAG (M_Cat(IV)) | FLAG (M_Cat(GB)) | FLAG (M_Cat(DOTTEDCIRCLE))) |
93 | |
94 | static inline bool |
95 | is_consonant_myanmar (const hb_glyph_info_t &info) |
96 | { |
97 | return is_one_of_myanmar (info, CONSONANT_FLAGS_MYANMAR); |
98 | } |
99 | |
100 | |
101 | static bool |
102 | setup_syllables_myanmar (const hb_ot_shape_plan_t *plan, |
103 | hb_font_t *font, |
104 | hb_buffer_t *buffer); |
105 | static bool |
106 | reorder_myanmar (const hb_ot_shape_plan_t *plan, |
107 | hb_font_t *font, |
108 | hb_buffer_t *buffer); |
109 | |
110 | static void |
111 | collect_features_myanmar (hb_ot_shape_planner_t *plan) |
112 | { |
113 | hb_ot_map_builder_t *map = &plan->map; |
114 | |
115 | /* Do this before any lookups have been applied. */ |
116 | map->add_gsub_pause (setup_syllables_myanmar); |
117 | |
118 | map->enable_feature (HB_TAG('l','o','c','l'), F_PER_SYLLABLE); |
119 | /* The Indic specs do not require ccmp, but we apply it here since if |
120 | * there is a use of it, it's typically at the beginning. */ |
121 | map->enable_feature (HB_TAG('c','c','m','p'), F_PER_SYLLABLE); |
122 | |
123 | |
124 | map->add_gsub_pause (reorder_myanmar); |
125 | |
126 | for (unsigned int i = 0; i < ARRAY_LENGTH (myanmar_basic_features); i++) |
127 | { |
128 | map->enable_feature (myanmar_basic_features[i], F_MANUAL_ZWJ | F_PER_SYLLABLE); |
129 | map->add_gsub_pause (nullptr); |
130 | } |
131 | map->add_gsub_pause (hb_syllabic_clear_var); // Don't need syllables anymore, use stop to free buffer var |
132 | |
133 | for (unsigned int i = 0; i < ARRAY_LENGTH (myanmar_other_features); i++) |
134 | map->enable_feature (myanmar_other_features[i], F_MANUAL_ZWJ); |
135 | } |
136 | |
137 | static void |
138 | setup_masks_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED, |
139 | hb_buffer_t *buffer, |
140 | hb_font_t *font HB_UNUSED) |
141 | { |
142 | HB_BUFFER_ALLOCATE_VAR (buffer, myanmar_category); |
143 | HB_BUFFER_ALLOCATE_VAR (buffer, myanmar_position); |
144 | |
145 | /* No masks, we just save information about characters. */ |
146 | |
147 | unsigned int count = buffer->len; |
148 | hb_glyph_info_t *info = buffer->info; |
149 | for (unsigned int i = 0; i < count; i++) |
150 | set_myanmar_properties (info[i]); |
151 | } |
152 | |
153 | static bool |
154 | setup_syllables_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED, |
155 | hb_font_t *font HB_UNUSED, |
156 | hb_buffer_t *buffer) |
157 | { |
158 | HB_BUFFER_ALLOCATE_VAR (buffer, syllable); |
159 | find_syllables_myanmar (buffer); |
160 | foreach_syllable (buffer, start, end) |
161 | buffer->unsafe_to_break (start, end); |
162 | return false; |
163 | } |
164 | |
165 | static int |
166 | compare_myanmar_order (const hb_glyph_info_t *pa, const hb_glyph_info_t *pb) |
167 | { |
168 | int a = pa->myanmar_position(); |
169 | int b = pb->myanmar_position(); |
170 | |
171 | return (int) a - (int) b; |
172 | } |
173 | |
174 | |
175 | /* Rules from: |
176 | * https://docs.microsoft.com/en-us/typography/script-development/myanmar */ |
177 | |
178 | static void |
179 | initial_reordering_consonant_syllable (hb_buffer_t *buffer, |
180 | unsigned int start, unsigned int end) |
181 | { |
182 | hb_glyph_info_t *info = buffer->info; |
183 | |
184 | unsigned int base = end; |
185 | bool has_reph = false; |
186 | |
187 | { |
188 | unsigned int limit = start; |
189 | if (start + 3 <= end && |
190 | info[start ].myanmar_category() == M_Cat(Ra) && |
191 | info[start+1].myanmar_category() == M_Cat(As) && |
192 | info[start+2].myanmar_category() == M_Cat(H)) |
193 | { |
194 | limit += 3; |
195 | base = start; |
196 | has_reph = true; |
197 | } |
198 | |
199 | { |
200 | if (!has_reph) |
201 | base = limit; |
202 | |
203 | for (unsigned int i = limit; i < end; i++) |
204 | if (is_consonant_myanmar (info[i])) |
205 | { |
206 | base = i; |
207 | break; |
208 | } |
209 | } |
210 | } |
211 | |
212 | /* Reorder! */ |
213 | { |
214 | unsigned int i = start; |
215 | for (; i < start + (has_reph ? 3 : 0); i++) |
216 | info[i].myanmar_position() = POS_AFTER_MAIN; |
217 | for (; i < base; i++) |
218 | info[i].myanmar_position() = POS_PRE_C; |
219 | if (i < end) |
220 | { |
221 | info[i].myanmar_position() = POS_BASE_C; |
222 | i++; |
223 | } |
224 | myanmar_position_t pos = POS_AFTER_MAIN; |
225 | /* The following loop may be ugly, but it implements all of |
226 | * Myanmar reordering! */ |
227 | for (; i < end; i++) |
228 | { |
229 | if (info[i].myanmar_category() == M_Cat(MR)) /* Pre-base reordering */ |
230 | { |
231 | info[i].myanmar_position() = POS_PRE_C; |
232 | continue; |
233 | } |
234 | if (info[i].myanmar_category() == M_Cat(VPre)) /* Left matra */ |
235 | { |
236 | info[i].myanmar_position() = POS_PRE_M; |
237 | continue; |
238 | } |
239 | if (info[i].myanmar_category() == M_Cat(VS)) |
240 | { |
241 | info[i].myanmar_position() = info[i - 1].myanmar_position(); |
242 | continue; |
243 | } |
244 | |
245 | if (pos == POS_AFTER_MAIN && info[i].myanmar_category() == M_Cat(VBlw)) |
246 | { |
247 | pos = POS_BELOW_C; |
248 | info[i].myanmar_position() = pos; |
249 | continue; |
250 | } |
251 | |
252 | if (pos == POS_BELOW_C && info[i].myanmar_category() == M_Cat(A)) |
253 | { |
254 | info[i].myanmar_position() = POS_BEFORE_SUB; |
255 | continue; |
256 | } |
257 | if (pos == POS_BELOW_C && info[i].myanmar_category() == M_Cat(VBlw)) |
258 | { |
259 | info[i].myanmar_position() = pos; |
260 | continue; |
261 | } |
262 | if (pos == POS_BELOW_C && info[i].myanmar_category() != M_Cat(A)) |
263 | { |
264 | pos = POS_AFTER_SUB; |
265 | info[i].myanmar_position() = pos; |
266 | continue; |
267 | } |
268 | info[i].myanmar_position() = pos; |
269 | } |
270 | } |
271 | |
272 | /* Sit tight, rock 'n roll! */ |
273 | buffer->sort (start, end, compare_myanmar_order); |
274 | |
275 | /* Flip left-matra sequence. */ |
276 | unsigned first_left_matra = end; |
277 | unsigned last_left_matra = end; |
278 | for (unsigned int i = start; i < end; i++) |
279 | { |
280 | if (info[i].myanmar_position() == POS_PRE_M) |
281 | { |
282 | if (first_left_matra == end) |
283 | first_left_matra = i; |
284 | last_left_matra = i; |
285 | } |
286 | } |
287 | /* https://github.com/harfbuzz/harfbuzz/issues/3863 */ |
288 | if (first_left_matra < last_left_matra) |
289 | { |
290 | /* No need to merge clusters, done already? */ |
291 | buffer->reverse_range (first_left_matra, last_left_matra + 1); |
292 | /* Reverse back VS, etc. */ |
293 | unsigned i = first_left_matra; |
294 | for (unsigned j = i; j <= last_left_matra; j++) |
295 | if (info[j].myanmar_category() == M_Cat(VPre)) |
296 | { |
297 | buffer->reverse_range (i, j + 1); |
298 | i = j + 1; |
299 | } |
300 | } |
301 | } |
302 | |
303 | static void |
304 | reorder_syllable_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED, |
305 | hb_face_t *face HB_UNUSED, |
306 | hb_buffer_t *buffer, |
307 | unsigned int start, unsigned int end) |
308 | { |
309 | myanmar_syllable_type_t syllable_type = (myanmar_syllable_type_t) (buffer->info[start].syllable() & 0x0F); |
310 | switch (syllable_type) { |
311 | |
312 | case myanmar_broken_cluster: /* We already inserted dotted-circles, so just call the consonant_syllable. */ |
313 | case myanmar_consonant_syllable: |
314 | initial_reordering_consonant_syllable (buffer, start, end); |
315 | break; |
316 | |
317 | case myanmar_non_myanmar_cluster: |
318 | break; |
319 | } |
320 | } |
321 | |
322 | static bool |
323 | reorder_myanmar (const hb_ot_shape_plan_t *plan, |
324 | hb_font_t *font, |
325 | hb_buffer_t *buffer) |
326 | { |
327 | bool ret = false; |
328 | if (buffer->message (font, "start reordering myanmar" )) |
329 | { |
330 | if (hb_syllabic_insert_dotted_circles (font, buffer, |
331 | myanmar_broken_cluster, |
332 | M_Cat(DOTTEDCIRCLE))) |
333 | ret = true; |
334 | |
335 | foreach_syllable (buffer, start, end) |
336 | reorder_syllable_myanmar (plan, font->face, buffer, start, end); |
337 | (void) buffer->message (font, "end reordering myanmar" ); |
338 | } |
339 | |
340 | HB_BUFFER_DEALLOCATE_VAR (buffer, myanmar_category); |
341 | HB_BUFFER_DEALLOCATE_VAR (buffer, myanmar_position); |
342 | |
343 | return ret; |
344 | } |
345 | |
346 | |
347 | const hb_ot_shaper_t _hb_ot_shaper_myanmar = |
348 | { |
349 | collect_features_myanmar, |
350 | nullptr, /* override_features */ |
351 | nullptr, /* data_create */ |
352 | nullptr, /* data_destroy */ |
353 | nullptr, /* preprocess_text */ |
354 | nullptr, /* postprocess_glyphs */ |
355 | nullptr, /* decompose */ |
356 | nullptr, /* compose */ |
357 | setup_masks_myanmar, |
358 | nullptr, /* reorder_marks */ |
359 | HB_TAG_NONE, /* gpos_tag */ |
360 | HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT, |
361 | HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY, |
362 | false, /* fallback_position */ |
363 | }; |
364 | |
365 | |
366 | #ifndef HB_NO_OT_SHAPER_MYANMAR_ZAWGYI |
367 | /* Ugly Zawgyi encoding. |
368 | * Disable all auto processing. |
369 | * https://github.com/harfbuzz/harfbuzz/issues/1162 */ |
370 | const hb_ot_shaper_t _hb_ot_shaper_myanmar_zawgyi = |
371 | { |
372 | nullptr, /* collect_features */ |
373 | nullptr, /* override_features */ |
374 | nullptr, /* data_create */ |
375 | nullptr, /* data_destroy */ |
376 | nullptr, /* preprocess_text */ |
377 | nullptr, /* postprocess_glyphs */ |
378 | nullptr, /* decompose */ |
379 | nullptr, /* compose */ |
380 | nullptr, /* setup_masks */ |
381 | nullptr, /* reorder_marks */ |
382 | HB_TAG_NONE, /* gpos_tag */ |
383 | HB_OT_SHAPE_NORMALIZATION_MODE_NONE, |
384 | HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE, |
385 | false, /* fallback_position */ |
386 | }; |
387 | #endif |
388 | |
389 | |
390 | #endif |
391 | |