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-ot-map-private.hh"
30
31 #include "hb-ot-layout-private.hh"
32
33
34 void
add_lookups(hb_face_t * face,unsigned int table_index,unsigned int feature_index,hb_mask_t mask,bool auto_zwj)35 hb_ot_map_t::add_lookups (hb_face_t *face,
36 unsigned int table_index,
37 unsigned int feature_index,
38 hb_mask_t mask,
39 bool auto_zwj)
40 {
41 unsigned int lookup_indices[32];
42 unsigned int offset, len;
43 unsigned int table_lookup_count;
44
45 table_lookup_count = hb_ot_layout_table_get_lookup_count (face, table_tags[table_index]);
46
47 offset = 0;
48 do {
49 len = ARRAY_LENGTH (lookup_indices);
50 hb_ot_layout_feature_get_lookups (face,
51 table_tags[table_index],
52 feature_index,
53 offset, &len,
54 lookup_indices);
55
56 for (unsigned int i = 0; i < len; i++)
57 {
58 if (lookup_indices[i] >= table_lookup_count)
59 continue;
60 hb_ot_map_t::lookup_map_t *lookup = lookups[table_index].push ();
61 if (unlikely (!lookup))
62 return;
63 lookup->mask = mask;
64 lookup->index = lookup_indices[i];
65 lookup->auto_zwj = auto_zwj;
66 }
67
68 offset += len;
69 } while (len == ARRAY_LENGTH (lookup_indices));
70 }
71
hb_ot_map_builder_t(hb_face_t * face_,const hb_segment_properties_t * props_)72 hb_ot_map_builder_t::hb_ot_map_builder_t (hb_face_t *face_,
73 const hb_segment_properties_t *props_)
74 {
75 memset (this, 0, sizeof (*this));
76
77 face = face_;
78 props = *props_;
79
80
81 /* Fetch script/language indices for GSUB/GPOS. We need these later to skip
82 * features not available in either table and not waste precious bits for them. */
83
84 hb_tag_t script_tags[3] = {HB_TAG_NONE, HB_TAG_NONE, HB_TAG_NONE};
85 hb_tag_t language_tag;
86
87 hb_ot_tags_from_script (props.script, &script_tags[0], &script_tags[1]);
88 language_tag = hb_ot_tag_from_language (props.language);
89
90 for (unsigned int table_index = 0; table_index < 2; table_index++) {
91 hb_tag_t table_tag = table_tags[table_index];
92 found_script[table_index] = hb_ot_layout_table_choose_script (face, table_tag, script_tags, &script_index[table_index], &chosen_script[table_index]);
93 hb_ot_layout_script_find_language (face, table_tag, script_index[table_index], language_tag, &language_index[table_index]);
94 }
95 }
96
add_feature(hb_tag_t tag,unsigned int value,hb_ot_map_feature_flags_t flags)97 void hb_ot_map_builder_t::add_feature (hb_tag_t tag, unsigned int value,
98 hb_ot_map_feature_flags_t flags)
99 {
100 feature_info_t *info = feature_infos.push();
101 if (unlikely (!info)) return;
102 if (unlikely (!tag)) return;
103 info->tag = tag;
104 info->seq = feature_infos.len;
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
112
collect_lookups(unsigned int table_index,hb_set_t * lookups_out) const113 void hb_ot_map_t::collect_lookups (unsigned int table_index, hb_set_t *lookups_out) const
114 {
115 for (unsigned int i = 0; i < lookups[table_index].len; i++)
116 hb_set_add (lookups_out, lookups[table_index][i].index);
117 }
118
add_pause(unsigned int table_index,hb_ot_map_t::pause_func_t pause_func)119 void hb_ot_map_builder_t::add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func)
120 {
121 stage_info_t *s = stages[table_index].push ();
122 if (likely (s)) {
123 s->index = current_stage[table_index];
124 s->pause_func = pause_func;
125 }
126
127 current_stage[table_index]++;
128 }
129
130 void
compile(hb_ot_map_t & m)131 hb_ot_map_builder_t::compile (hb_ot_map_t &m)
132 {
133 m.global_mask = 1;
134
135 unsigned int required_feature_index[2];
136 hb_tag_t required_feature_tag[2];
137 /* We default to applying required feature in stage 0. If the required
138 * feature has a tag that is known to the shaper, we apply required feature
139 * in the stage for that tag.
140 */
141 unsigned int required_feature_stage[2] = {0, 0};
142
143 for (unsigned int table_index = 0; table_index < 2; table_index++)
144 {
145 m.chosen_script[table_index] = chosen_script[table_index];
146 m.found_script[table_index] = found_script[table_index];
147
148 hb_ot_layout_language_get_required_feature (face,
149 table_tags[table_index],
150 script_index[table_index],
151 language_index[table_index],
152 &required_feature_index[table_index],
153 &required_feature_tag[table_index]);
154 }
155
156 if (!feature_infos.len)
157 return;
158
159 /* Sort features and merge duplicates */
160 {
161 feature_infos.qsort ();
162 unsigned int j = 0;
163 for (unsigned int i = 1; i < feature_infos.len; i++)
164 if (feature_infos[i].tag != feature_infos[j].tag)
165 feature_infos[++j] = feature_infos[i];
166 else {
167 if (feature_infos[i].flags & F_GLOBAL) {
168 feature_infos[j].flags |= F_GLOBAL;
169 feature_infos[j].max_value = feature_infos[i].max_value;
170 feature_infos[j].default_value = feature_infos[i].default_value;
171 } else {
172 feature_infos[j].flags &= ~F_GLOBAL;
173 feature_infos[j].max_value = MAX (feature_infos[j].max_value, feature_infos[i].max_value);
174 /* Inherit default_value from j */
175 }
176 feature_infos[j].flags |= (feature_infos[i].flags & F_HAS_FALLBACK);
177 feature_infos[j].stage[0] = MIN (feature_infos[j].stage[0], feature_infos[i].stage[0]);
178 feature_infos[j].stage[1] = MIN (feature_infos[j].stage[1], feature_infos[i].stage[1]);
179 }
180 feature_infos.shrink (j + 1);
181 }
182
183
184 /* Allocate bits now */
185 unsigned int next_bit = 1;
186 for (unsigned int i = 0; i < feature_infos.len; i++)
187 {
188 const feature_info_t *info = &feature_infos[i];
189
190 unsigned int bits_needed;
191
192 if ((info->flags & F_GLOBAL) && info->max_value == 1)
193 /* Uses the global bit */
194 bits_needed = 0;
195 else
196 bits_needed = _hb_bit_storage (info->max_value);
197
198 if (!info->max_value || next_bit + bits_needed > 8 * sizeof (hb_mask_t))
199 continue; /* Feature disabled, or not enough bits. */
200
201
202 hb_bool_t found = false;
203 unsigned int feature_index[2];
204 for (unsigned int table_index = 0; table_index < 2; table_index++)
205 {
206 if (required_feature_tag[table_index] == info->tag)
207 {
208 required_feature_stage[table_index] = info->stage[table_index];
209 found = true;
210 continue;
211 }
212 found |= hb_ot_layout_language_find_feature (face,
213 table_tags[table_index],
214 script_index[table_index],
215 language_index[table_index],
216 info->tag,
217 &feature_index[table_index]);
218 }
219 if (!found && !(info->flags & F_HAS_FALLBACK))
220 continue;
221
222
223 hb_ot_map_t::feature_map_t *map = m.features.push ();
224 if (unlikely (!map))
225 break;
226
227 map->tag = info->tag;
228 map->index[0] = feature_index[0];
229 map->index[1] = feature_index[1];
230 map->stage[0] = info->stage[0];
231 map->stage[1] = info->stage[1];
232 map->auto_zwj = !(info->flags & F_MANUAL_ZWJ);
233 if ((info->flags & F_GLOBAL) && info->max_value == 1) {
234 /* Uses the global bit */
235 map->shift = 0;
236 map->mask = 1;
237 } else {
238 map->shift = next_bit;
239 map->mask = (1 << (next_bit + bits_needed)) - (1 << next_bit);
240 next_bit += bits_needed;
241 m.global_mask |= (info->default_value << map->shift) & map->mask;
242 }
243 map->_1_mask = (1 << map->shift) & map->mask;
244 map->needs_fallback = !found;
245
246 }
247 feature_infos.shrink (0); /* Done with these */
248
249
250 add_gsub_pause (NULL);
251 add_gpos_pause (NULL);
252
253 for (unsigned int table_index = 0; table_index < 2; table_index++)
254 {
255 /* Collect lookup indices for features */
256
257 unsigned int stage_index = 0;
258 unsigned int last_num_lookups = 0;
259 for (unsigned stage = 0; stage < current_stage[table_index]; stage++)
260 {
261 if (required_feature_index[table_index] != HB_OT_LAYOUT_NO_FEATURE_INDEX &&
262 required_feature_stage[table_index] == stage)
263 m.add_lookups (face, table_index,
264 required_feature_index[table_index],
265 1 /* mask */,
266 true /* auto_zwj */);
267
268 for (unsigned i = 0; i < m.features.len; i++)
269 if (m.features[i].stage[table_index] == stage)
270 m.add_lookups (face, table_index,
271 m.features[i].index[table_index],
272 m.features[i].mask,
273 m.features[i].auto_zwj);
274
275 /* Sort lookups and merge duplicates */
276 if (last_num_lookups < m.lookups[table_index].len)
277 {
278 m.lookups[table_index].qsort (last_num_lookups, m.lookups[table_index].len);
279
280 unsigned int j = last_num_lookups;
281 for (unsigned int i = j + 1; i < m.lookups[table_index].len; i++)
282 if (m.lookups[table_index][i].index != m.lookups[table_index][j].index)
283 m.lookups[table_index][++j] = m.lookups[table_index][i];
284 else
285 {
286 m.lookups[table_index][j].mask |= m.lookups[table_index][i].mask;
287 m.lookups[table_index][j].auto_zwj &= m.lookups[table_index][i].auto_zwj;
288 }
289 m.lookups[table_index].shrink (j + 1);
290 }
291
292 last_num_lookups = m.lookups[table_index].len;
293
294 if (stage_index < stages[table_index].len && stages[table_index][stage_index].index == stage) {
295 hb_ot_map_t::stage_map_t *stage_map = m.stages[table_index].push ();
296 if (likely (stage_map)) {
297 stage_map->last_lookup = last_num_lookups;
298 stage_map->pause_func = stages[table_index][stage_index].pause_func;
299 }
300
301 stage_index++;
302 }
303 }
304 }
305 }
306