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-ot-shape-complex-indic-private.hh"
28
29 /* buffer var allocations */
30 #define sea_category() complex_var_u8_0() /* indic_category_t */
31 #define sea_position() complex_var_u8_1() /* indic_position_t */
32
33
34 /*
35 * South-East Asian shaper.
36 * Loosely based on the Myanmar spec / shaper.
37 * There is no OpenType spec for this.
38 */
39
40 static const hb_tag_t
41 basic_features[] =
42 {
43 /*
44 * Basic features.
45 * These features are applied in order, one at a time, after initial_reordering.
46 */
47 HB_TAG('p','r','e','f'),
48 HB_TAG('a','b','v','f'),
49 HB_TAG('b','l','w','f'),
50 HB_TAG('p','s','t','f'),
51 };
52 static const hb_tag_t
53 other_features[] =
54 {
55 /*
56 * Other features.
57 * These features are applied all at once, after final_reordering.
58 */
59 HB_TAG('p','r','e','s'),
60 HB_TAG('a','b','v','s'),
61 HB_TAG('b','l','w','s'),
62 HB_TAG('p','s','t','s'),
63 /* Positioning features, though we don't care about the types. */
64 HB_TAG('d','i','s','t'),
65 };
66
67 static void
68 setup_syllables (const hb_ot_shape_plan_t *plan,
69 hb_font_t *font,
70 hb_buffer_t *buffer);
71 static void
72 initial_reordering (const hb_ot_shape_plan_t *plan,
73 hb_font_t *font,
74 hb_buffer_t *buffer);
75 static void
76 final_reordering (const hb_ot_shape_plan_t *plan,
77 hb_font_t *font,
78 hb_buffer_t *buffer);
79
80 static void
collect_features_sea(hb_ot_shape_planner_t * plan)81 collect_features_sea (hb_ot_shape_planner_t *plan)
82 {
83 hb_ot_map_builder_t *map = &plan->map;
84
85 /* Do this before any lookups have been applied. */
86 map->add_gsub_pause (setup_syllables);
87
88 map->add_global_bool_feature (HB_TAG('l','o','c','l'));
89 /* The Indic specs do not require ccmp, but we apply it here since if
90 * there is a use of it, it's typically at the beginning. */
91 map->add_global_bool_feature (HB_TAG('c','c','m','p'));
92
93 map->add_gsub_pause (initial_reordering);
94 for (unsigned int i = 0; i < ARRAY_LENGTH (basic_features); i++)
95 {
96 map->add_feature (basic_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ);
97 map->add_gsub_pause (NULL);
98 }
99 map->add_gsub_pause (final_reordering);
100 for (unsigned int i = 0; i < ARRAY_LENGTH (other_features); i++)
101 map->add_feature (other_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ);
102 }
103
104 static void
override_features_sea(hb_ot_shape_planner_t * plan)105 override_features_sea (hb_ot_shape_planner_t *plan)
106 {
107 plan->map.add_feature (HB_TAG('l','i','g','a'), 0, F_GLOBAL);
108 }
109
110
111 enum syllable_type_t {
112 consonant_syllable,
113 broken_cluster,
114 non_sea_cluster,
115 };
116
117 #include "hb-ot-shape-complex-sea-machine.hh"
118
119
120 /* Note: This enum is duplicated in the -machine.rl source file.
121 * Not sure how to avoid duplication. */
122 enum sea_category_t {
123 // OT_C = 1,
124 OT_GB = 12, /* Generic Base XXX DOTTED CIRCLE only for now */
125 // OT_H = 4, /* Halant */
126 OT_IV = 2, /* Independent Vowel */
127 OT_MR = 22, /* Medial Ra */
128 // OT_CM = 17, /* Consonant Medial */
129 OT_VAbv = 26,
130 OT_VBlw = 27,
131 OT_VPre = 28,
132 OT_VPst = 29,
133 OT_T = 3, /* Tone Marks */
134 // OT_A = 10, /* Anusvara */
135 };
136
137 static inline void
set_sea_properties(hb_glyph_info_t & info)138 set_sea_properties (hb_glyph_info_t &info)
139 {
140 hb_codepoint_t u = info.codepoint;
141 unsigned int type = hb_indic_get_categories (u);
142 indic_category_t cat = (indic_category_t) (type & 0x7F);
143 indic_position_t pos = (indic_position_t) (type >> 8);
144
145 /* Medial Ra */
146 if (u == 0x1A55 || u == 0xAA34)
147 cat = (indic_category_t) OT_MR;
148
149 if (cat == OT_M)
150 {
151 switch ((int) pos)
152 {
153 case POS_PRE_C: cat = (indic_category_t) OT_VPre; break;
154 case POS_ABOVE_C: cat = (indic_category_t) OT_VAbv; break;
155 case POS_BELOW_C: cat = (indic_category_t) OT_VBlw; break;
156 case POS_POST_C: cat = (indic_category_t) OT_VPst; break;
157 }
158 }
159
160 info.sea_category() = (sea_category_t) cat;
161 info.sea_position() = pos;
162 }
163
164
165 static void
setup_masks_sea(const hb_ot_shape_plan_t * plan HB_UNUSED,hb_buffer_t * buffer,hb_font_t * font HB_UNUSED)166 setup_masks_sea (const hb_ot_shape_plan_t *plan HB_UNUSED,
167 hb_buffer_t *buffer,
168 hb_font_t *font HB_UNUSED)
169 {
170 HB_BUFFER_ALLOCATE_VAR (buffer, sea_category);
171 HB_BUFFER_ALLOCATE_VAR (buffer, sea_position);
172
173 /* We cannot setup masks here. We save information about characters
174 * and setup masks later on in a pause-callback. */
175
176 unsigned int count = buffer->len;
177 for (unsigned int i = 0; i < count; i++)
178 set_sea_properties (buffer->info[i]);
179 }
180
181 static void
setup_syllables(const hb_ot_shape_plan_t * plan HB_UNUSED,hb_font_t * font HB_UNUSED,hb_buffer_t * buffer)182 setup_syllables (const hb_ot_shape_plan_t *plan HB_UNUSED,
183 hb_font_t *font HB_UNUSED,
184 hb_buffer_t *buffer)
185 {
186 find_syllables (buffer);
187 }
188
189 static int
compare_sea_order(const hb_glyph_info_t * pa,const hb_glyph_info_t * pb)190 compare_sea_order (const hb_glyph_info_t *pa, const hb_glyph_info_t *pb)
191 {
192 int a = pa->sea_position();
193 int b = pb->sea_position();
194
195 return a < b ? -1 : a == b ? 0 : +1;
196 }
197
198
199 static void
initial_reordering_consonant_syllable(const hb_ot_shape_plan_t * plan,hb_face_t * face,hb_buffer_t * buffer,unsigned int start,unsigned int end)200 initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan,
201 hb_face_t *face,
202 hb_buffer_t *buffer,
203 unsigned int start, unsigned int end)
204 {
205 hb_glyph_info_t *info = buffer->info;
206 unsigned int base = start;
207
208 /* Reorder! */
209 unsigned int i = start;
210 for (; i < base; i++)
211 info[i].sea_position() = POS_PRE_C;
212 if (i < end)
213 {
214 info[i].sea_position() = POS_BASE_C;
215 i++;
216 }
217 for (; i < end; i++)
218 {
219 if (info[i].sea_category() == OT_MR) /* Pre-base reordering */
220 {
221 info[i].sea_position() = POS_PRE_C;
222 continue;
223 }
224 if (info[i].sea_category() == OT_VPre) /* Left matra */
225 {
226 info[i].sea_position() = POS_PRE_M;
227 continue;
228 }
229
230 info[i].sea_position() = POS_AFTER_MAIN;
231 }
232
233 buffer->merge_clusters (start, end);
234 /* Sit tight, rock 'n roll! */
235 hb_bubble_sort (info + start, end - start, compare_sea_order);
236 }
237
238 static void
initial_reordering_broken_cluster(const hb_ot_shape_plan_t * plan,hb_face_t * face,hb_buffer_t * buffer,unsigned int start,unsigned int end)239 initial_reordering_broken_cluster (const hb_ot_shape_plan_t *plan,
240 hb_face_t *face,
241 hb_buffer_t *buffer,
242 unsigned int start, unsigned int end)
243 {
244 /* We already inserted dotted-circles, so just call the consonant_syllable. */
245 initial_reordering_consonant_syllable (plan, face, buffer, start, end);
246 }
247
248 static void
initial_reordering_non_sea_cluster(const hb_ot_shape_plan_t * plan HB_UNUSED,hb_face_t * face HB_UNUSED,hb_buffer_t * buffer HB_UNUSED,unsigned int start HB_UNUSED,unsigned int end HB_UNUSED)249 initial_reordering_non_sea_cluster (const hb_ot_shape_plan_t *plan HB_UNUSED,
250 hb_face_t *face HB_UNUSED,
251 hb_buffer_t *buffer HB_UNUSED,
252 unsigned int start HB_UNUSED, unsigned int end HB_UNUSED)
253 {
254 /* Nothing to do right now. If we ever switch to using the output
255 * buffer in the reordering process, we'd need to next_glyph() here. */
256 }
257
258
259 static void
initial_reordering_syllable(const hb_ot_shape_plan_t * plan,hb_face_t * face,hb_buffer_t * buffer,unsigned int start,unsigned int end)260 initial_reordering_syllable (const hb_ot_shape_plan_t *plan,
261 hb_face_t *face,
262 hb_buffer_t *buffer,
263 unsigned int start, unsigned int end)
264 {
265 syllable_type_t syllable_type = (syllable_type_t) (buffer->info[start].syllable() & 0x0F);
266 switch (syllable_type) {
267 case consonant_syllable: initial_reordering_consonant_syllable (plan, face, buffer, start, end); return;
268 case broken_cluster: initial_reordering_broken_cluster (plan, face, buffer, start, end); return;
269 case non_sea_cluster: initial_reordering_non_sea_cluster (plan, face, buffer, start, end); return;
270 }
271 }
272
273 static inline void
insert_dotted_circles(const hb_ot_shape_plan_t * plan HB_UNUSED,hb_font_t * font,hb_buffer_t * buffer)274 insert_dotted_circles (const hb_ot_shape_plan_t *plan HB_UNUSED,
275 hb_font_t *font,
276 hb_buffer_t *buffer)
277 {
278 /* Note: This loop is extra overhead, but should not be measurable. */
279 bool has_broken_syllables = false;
280 unsigned int count = buffer->len;
281 for (unsigned int i = 0; i < count; i++)
282 if ((buffer->info[i].syllable() & 0x0F) == broken_cluster) {
283 has_broken_syllables = true;
284 break;
285 }
286 if (likely (!has_broken_syllables))
287 return;
288
289
290 hb_codepoint_t dottedcircle_glyph;
291 if (!font->get_glyph (0x25CC, 0, &dottedcircle_glyph))
292 return;
293
294 hb_glyph_info_t dottedcircle = {0};
295 dottedcircle.codepoint = 0x25CC;
296 set_sea_properties (dottedcircle);
297 dottedcircle.codepoint = dottedcircle_glyph;
298
299 buffer->clear_output ();
300
301 buffer->idx = 0;
302 unsigned int last_syllable = 0;
303 while (buffer->idx < buffer->len)
304 {
305 unsigned int syllable = buffer->cur().syllable();
306 syllable_type_t syllable_type = (syllable_type_t) (syllable & 0x0F);
307 if (unlikely (last_syllable != syllable && syllable_type == broken_cluster))
308 {
309 last_syllable = syllable;
310
311 hb_glyph_info_t info = dottedcircle;
312 info.cluster = buffer->cur().cluster;
313 info.mask = buffer->cur().mask;
314 info.syllable() = buffer->cur().syllable();
315
316 buffer->output_info (info);
317 }
318 else
319 buffer->next_glyph ();
320 }
321
322 buffer->swap_buffers ();
323 }
324
325 static void
initial_reordering(const hb_ot_shape_plan_t * plan,hb_font_t * font,hb_buffer_t * buffer)326 initial_reordering (const hb_ot_shape_plan_t *plan,
327 hb_font_t *font,
328 hb_buffer_t *buffer)
329 {
330 insert_dotted_circles (plan, font, buffer);
331
332 hb_glyph_info_t *info = buffer->info;
333 unsigned int count = buffer->len;
334 if (unlikely (!count)) return;
335 unsigned int last = 0;
336 unsigned int last_syllable = info[0].syllable();
337 for (unsigned int i = 1; i < count; i++)
338 if (last_syllable != info[i].syllable()) {
339 initial_reordering_syllable (plan, font->face, buffer, last, i);
340 last = i;
341 last_syllable = info[last].syllable();
342 }
343 initial_reordering_syllable (plan, font->face, buffer, last, count);
344 }
345
346 static void
final_reordering(const hb_ot_shape_plan_t * plan,hb_font_t * font HB_UNUSED,hb_buffer_t * buffer)347 final_reordering (const hb_ot_shape_plan_t *plan,
348 hb_font_t *font HB_UNUSED,
349 hb_buffer_t *buffer)
350 {
351 hb_glyph_info_t *info = buffer->info;
352 unsigned int count = buffer->len;
353
354 /* Zero syllables now... */
355 for (unsigned int i = 0; i < count; i++)
356 info[i].syllable() = 0;
357
358 HB_BUFFER_DEALLOCATE_VAR (buffer, sea_category);
359 HB_BUFFER_DEALLOCATE_VAR (buffer, sea_position);
360 }
361
362
363 static hb_ot_shape_normalization_mode_t
normalization_preference_sea(const hb_segment_properties_t * props HB_UNUSED)364 normalization_preference_sea (const hb_segment_properties_t *props HB_UNUSED)
365 {
366 return HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT;
367 }
368
369
370 const hb_ot_complex_shaper_t _hb_ot_complex_shaper_sea =
371 {
372 "sea",
373 collect_features_sea,
374 override_features_sea,
375 NULL, /* data_create */
376 NULL, /* data_destroy */
377 NULL, /* preprocess_text */
378 normalization_preference_sea,
379 NULL, /* decompose */
380 NULL, /* compose */
381 setup_masks_sea,
382 HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE,
383 false, /* fallback_position */
384 };
385