1/*
2 * Copyright © 2009,2010 Red Hat, Inc.
3 * Copyright © 2010,2011,2013 Google, Inc.
4 *
5 * This is part of HarfBuzz, a text shaping library.
6 *
7 * Permission is hereby granted, without written agreement and without
8 * license or royalty fees, to use, copy, modify, and distribute this
9 * software and its documentation for any purpose, provided that the
10 * above copyright notice and the following two paragraphs appear in
11 * all copies of this software.
12 *
13 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
14 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
15 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
16 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
17 * DAMAGE.
18 *
19 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
20 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
22 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
23 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
24 *
25 * Red Hat Author(s): Behdad Esfahbod
26 * Google Author(s): Behdad Esfahbod
27 */
28
29#include "hb.hh"
30
31#ifndef HB_NO_OT_SHAPE
32
33#include "hb-ot-map.hh"
34#include "hb-ot-shape.hh"
35#include "hb-ot-layout.hh"
36
37
38void hb_ot_map_t::collect_lookups (unsigned int table_index, hb_set_t *lookups_out) const
39{
40 for (unsigned int i = 0; i < lookups[table_index].length; i++)
41 lookups_out->add (lookups[table_index][i].index);
42}
43
44
45hb_ot_map_builder_t::hb_ot_map_builder_t (hb_face_t *face_,
46 const hb_segment_properties_t &props_)
47{
48 hb_memset (this, 0, sizeof (*this));
49
50 feature_infos.init ();
51 for (unsigned int table_index = 0; table_index < 2; table_index++)
52 stages[table_index].init ();
53
54 face = face_;
55 props = props_;
56
57 /* Fetch script/language indices for GSUB/GPOS. We need these later to skip
58 * features not available in either table and not waste precious bits for them. */
59
60 unsigned int script_count = HB_OT_MAX_TAGS_PER_SCRIPT;
61 unsigned int language_count = HB_OT_MAX_TAGS_PER_LANGUAGE;
62 hb_tag_t script_tags[HB_OT_MAX_TAGS_PER_SCRIPT];
63 hb_tag_t language_tags[HB_OT_MAX_TAGS_PER_LANGUAGE];
64
65 hb_ot_tags_from_script_and_language (props.script,
66 props.language,
67 &script_count,
68 script_tags,
69 &language_count,
70 language_tags);
71
72 for (unsigned int table_index = 0; table_index < 2; table_index++)
73 {
74 hb_tag_t table_tag = table_tags[table_index];
75 found_script[table_index] = (bool) hb_ot_layout_table_select_script (face,
76 table_tag,
77 script_count,
78 script_tags,
79 &script_index[table_index],
80 &chosen_script[table_index]);
81 hb_ot_layout_script_select_language (face,
82 table_tag,
83 script_index[table_index],
84 language_count,
85 language_tags,
86 &language_index[table_index]);
87 }
88}
89
90hb_ot_map_builder_t::~hb_ot_map_builder_t ()
91{
92 feature_infos.fini ();
93 for (unsigned int table_index = 0; table_index < 2; table_index++)
94 stages[table_index].fini ();
95}
96
97void hb_ot_map_builder_t::add_feature (hb_tag_t tag,
98 hb_ot_map_feature_flags_t flags,
99 unsigned int value)
100{
101 if (unlikely (!tag)) return;
102 feature_info_t *info = feature_infos.push();
103 info->tag = tag;
104 info->seq = feature_infos.length;
105 info->max_value = value;
106 info->flags = flags;
107 info->default_value = (flags & F_GLOBAL) ? value : 0;
108 info->stage[0] = current_stage[0];
109 info->stage[1] = current_stage[1];
110}
111
112bool hb_ot_map_builder_t::has_feature (hb_tag_t tag)
113{
114 for (unsigned int table_index = 0; table_index < 2; table_index++)
115 {
116 if (hb_ot_layout_language_find_feature (face,
117 table_tags[table_index],
118 script_index[table_index],
119 language_index[table_index],
120 tag,
121 nullptr))
122 return true;
123 }
124 return false;
125}
126
127void
128hb_ot_map_builder_t::add_lookups (hb_ot_map_t &m,
129 unsigned int table_index,
130 unsigned int feature_index,
131 unsigned int variations_index,
132 hb_mask_t mask,
133 bool auto_zwnj,
134 bool auto_zwj,
135 bool random,
136 bool per_syllable,
137 hb_tag_t feature_tag)
138{
139 unsigned int lookup_indices[32];
140 unsigned int offset, len;
141 unsigned int table_lookup_count;
142
143 table_lookup_count = hb_ot_layout_table_get_lookup_count (face, table_tags[table_index]);
144
145 offset = 0;
146 do {
147 len = ARRAY_LENGTH (lookup_indices);
148 hb_ot_layout_feature_with_variations_get_lookups (face,
149 table_tags[table_index],
150 feature_index,
151 variations_index,
152 offset, &len,
153 lookup_indices);
154
155 for (unsigned int i = 0; i < len; i++)
156 {
157 if (lookup_indices[i] >= table_lookup_count)
158 continue;
159 hb_ot_map_t::lookup_map_t *lookup = m.lookups[table_index].push ();
160 lookup->mask = mask;
161 lookup->index = lookup_indices[i];
162 lookup->auto_zwnj = auto_zwnj;
163 lookup->auto_zwj = auto_zwj;
164 lookup->random = random;
165 lookup->per_syllable = per_syllable;
166 lookup->feature_tag = feature_tag;
167 }
168
169 offset += len;
170 } while (len == ARRAY_LENGTH (lookup_indices));
171}
172
173
174void hb_ot_map_builder_t::add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func)
175{
176 stage_info_t *s = stages[table_index].push ();
177 s->index = current_stage[table_index];
178 s->pause_func = pause_func;
179
180 current_stage[table_index]++;
181}
182
183void
184hb_ot_map_builder_t::compile (hb_ot_map_t &m,
185 const hb_ot_shape_plan_key_t &key)
186{
187 unsigned int global_bit_shift = 8 * sizeof (hb_mask_t) - 1;
188 unsigned int global_bit_mask = 1u << global_bit_shift;
189
190 m.global_mask = global_bit_mask;
191
192 unsigned int required_feature_index[2];
193 hb_tag_t required_feature_tag[2];
194 /* We default to applying required feature in stage 0. If the required
195 * feature has a tag that is known to the shaper, we apply required feature
196 * in the stage for that tag.
197 */
198 unsigned int required_feature_stage[2] = {0, 0};
199
200 for (unsigned int table_index = 0; table_index < 2; table_index++)
201 {
202 m.chosen_script[table_index] = chosen_script[table_index];
203 m.found_script[table_index] = found_script[table_index];
204
205 hb_ot_layout_language_get_required_feature (face,
206 table_tags[table_index],
207 script_index[table_index],
208 language_index[table_index],
209 &required_feature_index[table_index],
210 &required_feature_tag[table_index]);
211 }
212
213 /* Sort features and merge duplicates */
214 if (feature_infos.length)
215 {
216 if (!is_simple)
217 feature_infos.qsort ();
218 auto *f = feature_infos.arrayZ;
219 unsigned int j = 0;
220 unsigned count = feature_infos.length;
221 for (unsigned int i = 1; i < count; i++)
222 if (f[i].tag != f[j].tag)
223 f[++j] = f[i];
224 else {
225 if (f[i].flags & F_GLOBAL) {
226 f[j].flags |= F_GLOBAL;
227 f[j].max_value = f[i].max_value;
228 f[j].default_value = f[i].default_value;
229 } else {
230 if (f[j].flags & F_GLOBAL)
231 f[j].flags ^= F_GLOBAL;
232 f[j].max_value = hb_max (f[j].max_value, f[i].max_value);
233 /* Inherit default_value from j */
234 }
235 f[j].flags |= (f[i].flags & F_HAS_FALLBACK);
236 f[j].stage[0] = hb_min (f[j].stage[0], f[i].stage[0]);
237 f[j].stage[1] = hb_min (f[j].stage[1], f[i].stage[1]);
238 }
239 feature_infos.shrink (j + 1);
240 }
241
242 hb_map_t feature_indices[2];
243 for (unsigned int table_index = 0; table_index < 2; table_index++)
244 hb_ot_layout_collect_features_map (face,
245 table_tags[table_index],
246 script_index[table_index],
247 language_index[table_index],
248 &feature_indices[table_index]);
249
250 /* Allocate bits now */
251 static_assert ((!(HB_GLYPH_FLAG_DEFINED & (HB_GLYPH_FLAG_DEFINED + 1))), "");
252 unsigned int next_bit = hb_popcount (HB_GLYPH_FLAG_DEFINED) + 1;
253
254 unsigned count = feature_infos.length;
255 for (unsigned int i = 0; i < count; i++)
256 {
257 const feature_info_t *info = &feature_infos[i];
258
259 unsigned int bits_needed;
260
261 if ((info->flags & F_GLOBAL) && info->max_value == 1)
262 /* Uses the global bit */
263 bits_needed = 0;
264 else
265 /* Limit bits per feature. */
266 bits_needed = hb_min (HB_OT_MAP_MAX_BITS, hb_bit_storage (info->max_value));
267
268 if (!info->max_value || next_bit + bits_needed >= global_bit_shift)
269 continue; /* Feature disabled, or not enough bits. */
270
271 bool found = false;
272 unsigned int feature_index[2];
273 for (unsigned int table_index = 0; table_index < 2; table_index++)
274 {
275 if (required_feature_tag[table_index] == info->tag)
276 required_feature_stage[table_index] = info->stage[table_index];
277
278 hb_codepoint_t *index;
279 if (feature_indices[table_index].has (info->tag, &index))
280 {
281 feature_index[table_index] = *index;
282 found = true;
283 }
284 else
285 feature_index[table_index] = HB_OT_LAYOUT_NO_FEATURE_INDEX;
286 }
287 if (!found && (info->flags & F_GLOBAL_SEARCH))
288 {
289 for (unsigned int table_index = 0; table_index < 2; table_index++)
290 {
291 found |= (bool) hb_ot_layout_table_find_feature (face,
292 table_tags[table_index],
293 info->tag,
294 &feature_index[table_index]);
295 }
296 }
297 if (!found && !(info->flags & F_HAS_FALLBACK))
298 continue;
299
300
301 hb_ot_map_t::feature_map_t *map = m.features.push ();
302
303 map->tag = info->tag;
304 map->index[0] = feature_index[0];
305 map->index[1] = feature_index[1];
306 map->stage[0] = info->stage[0];
307 map->stage[1] = info->stage[1];
308 map->auto_zwnj = !(info->flags & F_MANUAL_ZWNJ);
309 map->auto_zwj = !(info->flags & F_MANUAL_ZWJ);
310 map->random = !!(info->flags & F_RANDOM);
311 map->per_syllable = !!(info->flags & F_PER_SYLLABLE);
312 if ((info->flags & F_GLOBAL) && info->max_value == 1) {
313 /* Uses the global bit */
314 map->shift = global_bit_shift;
315 map->mask = global_bit_mask;
316 } else {
317 map->shift = next_bit;
318 map->mask = (1u << (next_bit + bits_needed)) - (1u << next_bit);
319 next_bit += bits_needed;
320 m.global_mask |= (info->default_value << map->shift) & map->mask;
321 }
322 map->_1_mask = (1u << map->shift) & map->mask;
323 map->needs_fallback = !found;
324 }
325 //feature_infos.shrink (0); /* Done with these */
326 if (is_simple)
327 m.features.qsort ();
328
329 add_gsub_pause (nullptr);
330 add_gpos_pause (nullptr);
331
332 for (unsigned int table_index = 0; table_index < 2; table_index++)
333 {
334 /* Collect lookup indices for features */
335 auto &lookups = m.lookups[table_index];
336
337 unsigned int stage_index = 0;
338 unsigned int last_num_lookups = 0;
339 for (unsigned stage = 0; stage < current_stage[table_index]; stage++)
340 {
341 if (required_feature_index[table_index] != HB_OT_LAYOUT_NO_FEATURE_INDEX &&
342 required_feature_stage[table_index] == stage)
343 add_lookups (m, table_index,
344 required_feature_index[table_index],
345 key.variations_index[table_index],
346 global_bit_mask);
347
348 for (auto &feature : m.features)
349 {
350 if (feature.stage[table_index] == stage)
351 add_lookups (m, table_index,
352 feature.index[table_index],
353 key.variations_index[table_index],
354 feature.mask,
355 feature.auto_zwnj,
356 feature.auto_zwj,
357 feature.random,
358 feature.per_syllable,
359 feature.tag);
360 }
361
362 /* Sort lookups and merge duplicates */
363 if (last_num_lookups + 1 < lookups.length)
364 {
365 lookups.as_array ().sub_array (last_num_lookups, lookups.length - last_num_lookups).qsort ();
366
367 unsigned int j = last_num_lookups;
368 for (unsigned int i = j + 1; i < lookups.length; i++)
369 if (lookups.arrayZ[i].index != lookups.arrayZ[j].index)
370 lookups.arrayZ[++j] = lookups.arrayZ[i];
371 else
372 {
373 lookups.arrayZ[j].mask |= lookups.arrayZ[i].mask;
374 lookups.arrayZ[j].auto_zwnj &= lookups.arrayZ[i].auto_zwnj;
375 lookups.arrayZ[j].auto_zwj &= lookups.arrayZ[i].auto_zwj;
376 }
377 lookups.shrink (j + 1);
378 }
379
380 last_num_lookups = lookups.length;
381
382 if (stage_index < stages[table_index].length && stages[table_index][stage_index].index == stage) {
383 hb_ot_map_t::stage_map_t *stage_map = m.stages[table_index].push ();
384 stage_map->last_lookup = last_num_lookups;
385 stage_map->pause_func = stages[table_index][stage_index].pause_func;
386
387 stage_index++;
388 }
389 }
390 }
391}
392
393
394#endif
395