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 hb_ot_map_t::collect_lookups (unsigned int table_index, hb_set_t *lookups_out) const
35 {
36 for (unsigned int i = 0; i < lookups[table_index].len; i++)
37 hb_set_add (lookups_out, lookups[table_index][i].index);
38 }
39
40
41 hb_ot_map_builder_t::hb_ot_map_builder_t (hb_face_t *face_,
42 const hb_segment_properties_t *props_)
43 {
44 memset (this, 0, sizeof (*this));
45
46 feature_infos.init ();
47 for (unsigned int table_index = 0; table_index < 2; table_index++)
48 stages[table_index].init ();
49
50 face = face_;
51 props = *props_;
52
53
54 /* Fetch script/language indices for GSUB/GPOS. We need these later to skip
55 * features not available in either table and not waste precious bits for them. */
56
57 hb_tag_t script_tags[3] = {HB_TAG_NONE, HB_TAG_NONE, HB_TAG_NONE};
58 hb_tag_t language_tag;
59
60 hb_ot_tags_from_script (props.script, &script_tags[0], &script_tags[1]);
61 language_tag = hb_ot_tag_from_language (props.language);
62
63 for (unsigned int table_index = 0; table_index < 2; table_index++) {
64 hb_tag_t table_tag = table_tags[table_index];
65 found_script[table_index] = (bool) hb_ot_layout_table_choose_script (face, table_tag, script_tags, &script_index[table_index], &chosen_script[table_index]);
66 hb_ot_layout_script_find_language (face, table_tag, script_index[table_index], language_tag, &language_index[table_index]);
67 }
68 }
69
70 hb_ot_map_builder_t::~hb_ot_map_builder_t (void)
71 {
72 feature_infos.fini ();
73 for (unsigned int table_index = 0; table_index < 2; table_index++)
74 stages[table_index].fini ();
75 }
76
77 void hb_ot_map_builder_t::add_feature (hb_tag_t tag, unsigned int value,
78 hb_ot_map_feature_flags_t flags)
79 {
80 feature_info_t *info = feature_infos.push();
81 if (unlikely (!tag)) return;
82 info->tag = tag;
83 info->seq = feature_infos.len;
84 info->max_value = value;
85 info->flags = flags;
86 info->default_value = (flags & F_GLOBAL) ? value : 0;
87 info->stage[0] = current_stage[0];
88 info->stage[1] = current_stage[1];
89 }
90
91 void
92 hb_ot_map_builder_t::add_lookups (hb_ot_map_t &m,
93 unsigned int table_index,
94 unsigned int feature_index,
95 unsigned int variations_index,
96 hb_mask_t mask,
97 bool auto_zwnj,
98 bool auto_zwj)
99 {
100 unsigned int lookup_indices[32];
101 unsigned int offset, len;
102 unsigned int table_lookup_count;
103
104 table_lookup_count = hb_ot_layout_table_get_lookup_count (face, table_tags[table_index]);
105
106 offset = 0;
107 do {
108 len = ARRAY_LENGTH (lookup_indices);
109 hb_ot_layout_feature_with_variations_get_lookups (face,
110 table_tags[table_index],
111 feature_index,
112 variations_index,
113 offset, &len,
114 lookup_indices);
115
116 for (unsigned int i = 0; i < len; i++)
117 {
118 if (lookup_indices[i] >= table_lookup_count)
119 continue;
120 hb_ot_map_t::lookup_map_t *lookup = m.lookups[table_index].push ();
121 lookup->mask = mask;
122 lookup->index = lookup_indices[i];
123 lookup->auto_zwnj = auto_zwnj;
124 lookup->auto_zwj = auto_zwj;
125 }
126
127 offset += len;
128 } while (len == ARRAY_LENGTH (lookup_indices));
129 }
130
131
132 void hb_ot_map_builder_t::add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func)
133 {
134 stage_info_t *s = stages[table_index].push ();
135 s->index = current_stage[table_index];
136 s->pause_func = pause_func;
137
138 current_stage[table_index]++;
139 }
140
141 void
142 hb_ot_map_builder_t::compile (hb_ot_map_t &m,
143 const int *coords,
144 unsigned int num_coords)
145 {
146 static_assert ((!(HB_GLYPH_FLAG_DEFINED & (HB_GLYPH_FLAG_DEFINED + 1))), "");
147 unsigned int global_bit_mask = HB_GLYPH_FLAG_DEFINED + 1;
148 unsigned int global_bit_shift = _hb_popcount (HB_GLYPH_FLAG_DEFINED);
149
150 m.global_mask = global_bit_mask;
151
152 unsigned int required_feature_index[2];
153 hb_tag_t required_feature_tag[2];
154 /* We default to applying required feature in stage 0. If the required
155 * feature has a tag that is known to the shaper, we apply required feature
156 * in the stage for that tag.
157 */
158 unsigned int required_feature_stage[2] = {0, 0};
159
160 for (unsigned int table_index = 0; table_index < 2; table_index++)
161 {
162 m.chosen_script[table_index] = chosen_script[table_index];
163 m.found_script[table_index] = found_script[table_index];
164
165 hb_ot_layout_language_get_required_feature (face,
166 table_tags[table_index],
167 script_index[table_index],
168 language_index[table_index],
169 &required_feature_index[table_index],
170 &required_feature_tag[table_index]);
171 }
172
173 /* Sort features and merge duplicates */
174 {
175 feature_infos.qsort ();
176 unsigned int j = 0;
177 for (unsigned int i = 1; i < feature_infos.len; i++)
178 if (feature_infos[i].tag != feature_infos[j].tag)
179 feature_infos[++j] = feature_infos[i];
180 else {
181 if (feature_infos[i].flags & F_GLOBAL) {
182 feature_infos[j].flags |= F_GLOBAL;
183 feature_infos[j].max_value = feature_infos[i].max_value;
184 feature_infos[j].default_value = feature_infos[i].default_value;
185 } else {
186 feature_infos[j].flags &= ~F_GLOBAL;
187 feature_infos[j].max_value = MAX (feature_infos[j].max_value, feature_infos[i].max_value);
188 /* Inherit default_value from j */
189 }
190 feature_infos[j].flags |= (feature_infos[i].flags & F_HAS_FALLBACK);
191 feature_infos[j].stage[0] = MIN (feature_infos[j].stage[0], feature_infos[i].stage[0]);
192 feature_infos[j].stage[1] = MIN (feature_infos[j].stage[1], feature_infos[i].stage[1]);
193 }
194 feature_infos.shrink (j + 1);
195 }
196
197
198 /* Allocate bits now */
199 unsigned int next_bit = global_bit_shift + 1;
200
201 for (unsigned int i = 0; i < feature_infos.len; i++)
202 {
203 const feature_info_t *info = &feature_infos[i];
204
205 unsigned int bits_needed;
206
207 if ((info->flags & F_GLOBAL) && info->max_value == 1)
208 /* Uses the global bit */
209 bits_needed = 0;
210 else
211 /* Limit to 8 bits per feature. */
212 bits_needed = MIN(8u, _hb_bit_storage (info->max_value));
213
214 if (!info->max_value || next_bit + bits_needed > 8 * sizeof (hb_mask_t))
215 continue; /* Feature disabled, or not enough bits. */
216
217
218 hb_bool_t found = false;
219 unsigned int feature_index[2];
220 for (unsigned int table_index = 0; table_index < 2; table_index++)
221 {
222 if (required_feature_tag[table_index] == info->tag)
223 required_feature_stage[table_index] = info->stage[table_index];
224
225 found |= hb_ot_layout_language_find_feature (face,
226 table_tags[table_index],
227 script_index[table_index],
228 language_index[table_index],
229 info->tag,
230 &feature_index[table_index]);
231 }
232 if (!found && (info->flags & F_GLOBAL_SEARCH))
233 {
234 for (unsigned int table_index = 0; table_index < 2; table_index++)
235 {
236 found |= hb_ot_layout_table_find_feature (face,
237 table_tags[table_index],
238 info->tag,
239 &feature_index[table_index]);
240 }
241 }
242 if (!found && !(info->flags & F_HAS_FALLBACK))
243 continue;
244
245
246 hb_ot_map_t::feature_map_t *map = m.features.push ();
247
248 map->tag = info->tag;
249 map->index[0] = feature_index[0];
250 map->index[1] = feature_index[1];
251 map->stage[0] = info->stage[0];
252 map->stage[1] = info->stage[1];
253 map->auto_zwnj = !(info->flags & F_MANUAL_ZWNJ);
254 map->auto_zwj = !(info->flags & F_MANUAL_ZWJ);
255 if ((info->flags & F_GLOBAL) && info->max_value == 1) {
256 /* Uses the global bit */
257 map->shift = global_bit_shift;
258 map->mask = global_bit_mask;
259 } else {
260 map->shift = next_bit;
261 map->mask = (1u << (next_bit + bits_needed)) - (1u << next_bit);
262 next_bit += bits_needed;
263 m.global_mask |= (info->default_value << map->shift) & map->mask;
264 }
265 map->_1_mask = (1u << map->shift) & map->mask;
266 map->needs_fallback = !found;
267
268 }
269 feature_infos.shrink (0); /* Done with these */
270
271
272 add_gsub_pause (nullptr);
273 add_gpos_pause (nullptr);
274
275 for (unsigned int table_index = 0; table_index < 2; table_index++)
276 {
277 /* Collect lookup indices for features */
278
279 unsigned int variations_index;
280 hb_ot_layout_table_find_feature_variations (face,
281 table_tags[table_index],
282 coords,
283 num_coords,
284 &variations_index);
285
286 unsigned int stage_index = 0;
287 unsigned int last_num_lookups = 0;
288 for (unsigned stage = 0; stage < current_stage[table_index]; stage++)
289 {
290 if (required_feature_index[table_index] != HB_OT_LAYOUT_NO_FEATURE_INDEX &&
291 required_feature_stage[table_index] == stage)
292 add_lookups (m, table_index,
293 required_feature_index[table_index],
294 variations_index,
295 global_bit_mask);
296
297 for (unsigned i = 0; i < m.features.len; i++)
298 if (m.features[i].stage[table_index] == stage)
299 add_lookups (m, table_index,
300 m.features[i].index[table_index],
301 variations_index,
302 m.features[i].mask,
303 m.features[i].auto_zwnj,
304 m.features[i].auto_zwj);
305
306 /* Sort lookups and merge duplicates */
307 if (last_num_lookups < m.lookups[table_index].len)
308 {
309 m.lookups[table_index].qsort (last_num_lookups, m.lookups[table_index].len);
310
311 unsigned int j = last_num_lookups;
312 for (unsigned int i = j + 1; i < m.lookups[table_index].len; i++)
313 if (m.lookups[table_index][i].index != m.lookups[table_index][j].index)
314 m.lookups[table_index][++j] = m.lookups[table_index][i];
315 else
316 {
317 m.lookups[table_index][j].mask |= m.lookups[table_index][i].mask;
318 m.lookups[table_index][j].auto_zwnj &= m.lookups[table_index][i].auto_zwnj;
319 m.lookups[table_index][j].auto_zwj &= m.lookups[table_index][i].auto_zwj;
320 }
321 m.lookups[table_index].shrink (j + 1);
322 }
323
324 last_num_lookups = m.lookups[table_index].len;
325
326 if (stage_index < stages[table_index].len && stages[table_index][stage_index].index == stage) {
327 hb_ot_map_t::stage_map_t *stage_map = m.stages[table_index].push ();
328 stage_map->last_lookup = last_num_lookups;
329 stage_map->pause_func = stages[table_index][stage_index].pause_func;
330
331 stage_index++;
332 }
333 }
334 }
335 }