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-shape-complex-myanmar.hh"
32 #include "hb-ot-shape-complex-myanmar-machine.hh"
33
34
35 /*
36 * Myanmar shaper.
37 */
38
39 static const hb_tag_t
40 myanmar_basic_features[] =
41 {
42 /*
43 * Basic features.
44 * These features are applied in order, one at a time, after reordering.
45 */
46 HB_TAG('r','p','h','f'),
47 HB_TAG('p','r','e','f'),
48 HB_TAG('b','l','w','f'),
49 HB_TAG('p','s','t','f'),
50 };
51 static const hb_tag_t
52 myanmar_other_features[] =
53 {
54 /*
55 * Other features.
56 * These features are applied all at once, after clearing syllables.
57 */
58 HB_TAG('p','r','e','s'),
59 HB_TAG('a','b','v','s'),
60 HB_TAG('b','l','w','s'),
61 HB_TAG('p','s','t','s'),
62 };
63
64 static void
65 setup_syllables_myanmar (const hb_ot_shape_plan_t *plan,
66 hb_font_t *font,
67 hb_buffer_t *buffer);
68 static void
69 reorder_myanmar (const hb_ot_shape_plan_t *plan,
70 hb_font_t *font,
71 hb_buffer_t *buffer);
72
73 static void
collect_features_myanmar(hb_ot_shape_planner_t * plan)74 collect_features_myanmar (hb_ot_shape_planner_t *plan)
75 {
76 hb_ot_map_builder_t *map = &plan->map;
77
78 /* Do this before any lookups have been applied. */
79 map->add_gsub_pause (setup_syllables_myanmar);
80
81 map->enable_feature (HB_TAG('l','o','c','l'));
82 /* The Indic specs do not require ccmp, but we apply it here since if
83 * there is a use of it, it's typically at the beginning. */
84 map->enable_feature (HB_TAG('c','c','m','p'));
85
86
87 map->add_gsub_pause (reorder_myanmar);
88
89 for (unsigned int i = 0; i < ARRAY_LENGTH (myanmar_basic_features); i++)
90 {
91 map->enable_feature (myanmar_basic_features[i], F_MANUAL_ZWJ);
92 map->add_gsub_pause (nullptr);
93 }
94
95 map->add_gsub_pause (_hb_clear_syllables);
96
97 for (unsigned int i = 0; i < ARRAY_LENGTH (myanmar_other_features); i++)
98 map->enable_feature (myanmar_other_features[i], F_MANUAL_ZWJ);
99 }
100
101 static void
setup_masks_myanmar(const hb_ot_shape_plan_t * plan HB_UNUSED,hb_buffer_t * buffer,hb_font_t * font HB_UNUSED)102 setup_masks_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
103 hb_buffer_t *buffer,
104 hb_font_t *font HB_UNUSED)
105 {
106 HB_BUFFER_ALLOCATE_VAR (buffer, myanmar_category);
107 HB_BUFFER_ALLOCATE_VAR (buffer, myanmar_position);
108
109 /* We cannot setup masks here. We save information about characters
110 * and setup masks later on in a pause-callback. */
111
112 unsigned int count = buffer->len;
113 hb_glyph_info_t *info = buffer->info;
114 for (unsigned int i = 0; i < count; i++)
115 set_myanmar_properties (info[i]);
116 }
117
118 static void
setup_syllables_myanmar(const hb_ot_shape_plan_t * plan HB_UNUSED,hb_font_t * font HB_UNUSED,hb_buffer_t * buffer)119 setup_syllables_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
120 hb_font_t *font HB_UNUSED,
121 hb_buffer_t *buffer)
122 {
123 find_syllables_myanmar (buffer);
124 foreach_syllable (buffer, start, end)
125 buffer->unsafe_to_break (start, end);
126 }
127
128 static int
compare_myanmar_order(const hb_glyph_info_t * pa,const hb_glyph_info_t * pb)129 compare_myanmar_order (const hb_glyph_info_t *pa, const hb_glyph_info_t *pb)
130 {
131 int a = pa->myanmar_position();
132 int b = pb->myanmar_position();
133
134 return a < b ? -1 : a == b ? 0 : +1;
135 }
136
137
138 /* Rules from:
139 * https://docs.microsoft.com/en-us/typography/script-development/myanmar */
140
141 static void
initial_reordering_consonant_syllable(hb_buffer_t * buffer,unsigned int start,unsigned int end)142 initial_reordering_consonant_syllable (hb_buffer_t *buffer,
143 unsigned int start, unsigned int end)
144 {
145 hb_glyph_info_t *info = buffer->info;
146
147 unsigned int base = end;
148 bool has_reph = false;
149
150 {
151 unsigned int limit = start;
152 if (start + 3 <= end &&
153 info[start ].myanmar_category() == OT_Ra &&
154 info[start+1].myanmar_category() == OT_As &&
155 info[start+2].myanmar_category() == OT_H)
156 {
157 limit += 3;
158 base = start;
159 has_reph = true;
160 }
161
162 {
163 if (!has_reph)
164 base = limit;
165
166 for (unsigned int i = limit; i < end; i++)
167 if (is_consonant (info[i]))
168 {
169 base = i;
170 break;
171 }
172 }
173 }
174
175 /* Reorder! */
176 {
177 unsigned int i = start;
178 for (; i < start + (has_reph ? 3 : 0); i++)
179 info[i].myanmar_position() = POS_AFTER_MAIN;
180 for (; i < base; i++)
181 info[i].myanmar_position() = POS_PRE_C;
182 if (i < end)
183 {
184 info[i].myanmar_position() = POS_BASE_C;
185 i++;
186 }
187 indic_position_t pos = POS_AFTER_MAIN;
188 /* The following loop may be ugly, but it implements all of
189 * Myanmar reordering! */
190 for (; i < end; i++)
191 {
192 if (info[i].myanmar_category() == OT_MR) /* Pre-base reordering */
193 {
194 info[i].myanmar_position() = POS_PRE_C;
195 continue;
196 }
197 if (info[i].myanmar_position() < POS_BASE_C) /* Left matra */
198 {
199 continue;
200 }
201 if (info[i].myanmar_category() == OT_VS)
202 {
203 info[i].myanmar_position() = info[i - 1].myanmar_position();
204 continue;
205 }
206
207 if (pos == POS_AFTER_MAIN && info[i].myanmar_category() == OT_VBlw)
208 {
209 pos = POS_BELOW_C;
210 info[i].myanmar_position() = pos;
211 continue;
212 }
213
214 if (pos == POS_BELOW_C && info[i].myanmar_category() == OT_A)
215 {
216 info[i].myanmar_position() = POS_BEFORE_SUB;
217 continue;
218 }
219 if (pos == POS_BELOW_C && info[i].myanmar_category() == OT_VBlw)
220 {
221 info[i].myanmar_position() = pos;
222 continue;
223 }
224 if (pos == POS_BELOW_C && info[i].myanmar_category() != OT_A)
225 {
226 pos = POS_AFTER_SUB;
227 info[i].myanmar_position() = pos;
228 continue;
229 }
230 info[i].myanmar_position() = pos;
231 }
232 }
233
234 /* Sit tight, rock 'n roll! */
235 buffer->sort (start, end, compare_myanmar_order);
236 }
237
238 static void
reorder_syllable_myanmar(const hb_ot_shape_plan_t * plan HB_UNUSED,hb_face_t * face HB_UNUSED,hb_buffer_t * buffer,unsigned int start,unsigned int end)239 reorder_syllable_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
240 hb_face_t *face HB_UNUSED,
241 hb_buffer_t *buffer,
242 unsigned int start, unsigned int end)
243 {
244 myanmar_syllable_type_t syllable_type = (myanmar_syllable_type_t) (buffer->info[start].syllable() & 0x0F);
245 switch (syllable_type) {
246
247 case myanmar_broken_cluster: /* We already inserted dotted-circles, so just call the consonant_syllable. */
248 case myanmar_consonant_syllable:
249 initial_reordering_consonant_syllable (buffer, start, end);
250 break;
251
252 case myanmar_punctuation_cluster:
253 case myanmar_non_myanmar_cluster:
254 break;
255 }
256 }
257
258 static void
reorder_myanmar(const hb_ot_shape_plan_t * plan,hb_font_t * font,hb_buffer_t * buffer)259 reorder_myanmar (const hb_ot_shape_plan_t *plan,
260 hb_font_t *font,
261 hb_buffer_t *buffer)
262 {
263 if (buffer->message (font, "start reordering myanmar"))
264 {
265 hb_syllabic_insert_dotted_circles (font, buffer,
266 myanmar_broken_cluster,
267 OT_GB);
268
269 foreach_syllable (buffer, start, end)
270 reorder_syllable_myanmar (plan, font->face, buffer, start, end);
271 (void) buffer->message (font, "end reordering myanmar");
272 }
273
274 HB_BUFFER_DEALLOCATE_VAR (buffer, myanmar_category);
275 HB_BUFFER_DEALLOCATE_VAR (buffer, myanmar_position);
276 }
277
278
279 const hb_ot_complex_shaper_t _hb_ot_complex_shaper_myanmar =
280 {
281 collect_features_myanmar,
282 nullptr, /* override_features */
283 nullptr, /* data_create */
284 nullptr, /* data_destroy */
285 nullptr, /* preprocess_text */
286 nullptr, /* postprocess_glyphs */
287 HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT,
288 nullptr, /* decompose */
289 nullptr, /* compose */
290 setup_masks_myanmar,
291 HB_TAG_NONE, /* gpos_tag */
292 nullptr, /* reorder_marks */
293 HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY,
294 false, /* fallback_position */
295 };
296
297
298 /* Ugly Zawgyi encoding.
299 * Disable all auto processing.
300 * https://github.com/harfbuzz/harfbuzz/issues/1162 */
301 const hb_ot_complex_shaper_t _hb_ot_complex_shaper_myanmar_zawgyi =
302 {
303 nullptr, /* collect_features */
304 nullptr, /* override_features */
305 nullptr, /* data_create */
306 nullptr, /* data_destroy */
307 nullptr, /* preprocess_text */
308 nullptr, /* postprocess_glyphs */
309 HB_OT_SHAPE_NORMALIZATION_MODE_NONE,
310 nullptr, /* decompose */
311 nullptr, /* compose */
312 nullptr, /* setup_masks */
313 HB_TAG_NONE, /* gpos_tag */
314 nullptr, /* reorder_marks */
315 HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE,
316 false, /* fallback_position */
317 };
318
319
320 #endif
321