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comparison: gfx/harfbuzz/src/hb-ot-shape-complex-arabic.cc

gfx/harfbuzz/src/hb-ot-shape-complex-arabic.cc

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TOR_BUG_9701
changeset 15
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-1:000000000000 0:b1841c7c211e
1 /*
2 * Copyright © 2010,2012 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-private.hh"
28 #include "hb-ot-shape-private.hh"
29
30
31 /* buffer var allocations */
32 #define arabic_shaping_action() complex_var_u8_0() /* arabic shaping action */
33
34
35 /*
36 * Bits used in the joining tables
37 */
38 enum {
39 JOINING_TYPE_U = 0,
40 JOINING_TYPE_L = 1,
41 JOINING_TYPE_R = 2,
42 JOINING_TYPE_D = 3,
43 JOINING_TYPE_C = JOINING_TYPE_D,
44 JOINING_GROUP_ALAPH = 4,
45 JOINING_GROUP_DALATH_RISH = 5,
46 NUM_STATE_MACHINE_COLS = 6,
47
48 JOINING_TYPE_T = 7,
49 JOINING_TYPE_X = 8 /* means: use general-category to choose between U or T. */
50 };
51
52 /*
53 * Joining types:
54 */
55
56 #include "hb-ot-shape-complex-arabic-table.hh"
57
58 static unsigned int get_joining_type (hb_codepoint_t u, hb_unicode_general_category_t gen_cat)
59 {
60 if (likely (hb_in_range<hb_codepoint_t> (u, JOINING_TABLE_FIRST, JOINING_TABLE_LAST))) {
61 unsigned int j_type = joining_table[u - JOINING_TABLE_FIRST];
62 if (likely (j_type != JOINING_TYPE_X))
63 return j_type;
64 }
65
66 /* Mongolian joining data is not in ArabicJoining.txt yet. */
67 if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x1800, 0x18AF)))
68 {
69 if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x1880, 0x1886)))
70 return JOINING_TYPE_U;
71
72 /* All letters, SIBE SYLLABLE BOUNDARY MARKER, and NIRUGU are D */
73 if ((FLAG(gen_cat) & (FLAG (HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER) |
74 FLAG (HB_UNICODE_GENERAL_CATEGORY_MODIFIER_LETTER)))
75 || u == 0x1807 || u == 0x180A)
76 return JOINING_TYPE_D;
77 }
78
79 /* 'Phags-pa joining data is not in ArabicJoining.txt yet. */
80 if (unlikely (hb_in_range<hb_codepoint_t> (u, 0xA840, 0xA872)))
81 {
82 if (unlikely (u == 0xA872))
83 return JOINING_TYPE_L;
84
85 return JOINING_TYPE_D;
86 }
87
88 if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x200C, 0x200D)))
89 {
90 return u == 0x200C ? JOINING_TYPE_U : JOINING_TYPE_C;
91 }
92
93 return (FLAG(gen_cat) & (FLAG(HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) | FLAG(HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK) | FLAG(HB_UNICODE_GENERAL_CATEGORY_FORMAT))) ?
94 JOINING_TYPE_T : JOINING_TYPE_U;
95 }
96
97 static const hb_tag_t arabic_features[] =
98 {
99 HB_TAG('i','n','i','t'),
100 HB_TAG('m','e','d','i'),
101 HB_TAG('f','i','n','a'),
102 HB_TAG('i','s','o','l'),
103 /* Syriac */
104 HB_TAG('m','e','d','2'),
105 HB_TAG('f','i','n','2'),
106 HB_TAG('f','i','n','3'),
107 HB_TAG_NONE
108 };
109
110
111 /* Same order as the feature array */
112 enum {
113 INIT,
114 MEDI,
115 FINA,
116 ISOL,
117
118 /* Syriac */
119 MED2,
120 FIN2,
121 FIN3,
122
123 NONE,
124
125 ARABIC_NUM_FEATURES = NONE
126 };
127
128 static const struct arabic_state_table_entry {
129 uint8_t prev_action;
130 uint8_t curr_action;
131 uint16_t next_state;
132 } arabic_state_table[][NUM_STATE_MACHINE_COLS] =
133 {
134 /* jt_U, jt_L, jt_R, jt_D, jg_ALAPH, jg_DALATH_RISH */
135
136 /* State 0: prev was U, not willing to join. */
137 { {NONE,NONE,0}, {NONE,ISOL,2}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,ISOL,1}, {NONE,ISOL,6}, },
138
139 /* State 1: prev was R or ISOL/ALAPH, not willing to join. */
140 { {NONE,NONE,0}, {NONE,ISOL,2}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,FIN2,5}, {NONE,ISOL,6}, },
141
142 /* State 2: prev was D/L in ISOL form, willing to join. */
143 { {NONE,NONE,0}, {NONE,ISOL,2}, {INIT,FINA,1}, {INIT,FINA,3}, {INIT,FINA,4}, {INIT,FINA,6}, },
144
145 /* State 3: prev was D in FINA form, willing to join. */
146 { {NONE,NONE,0}, {NONE,ISOL,2}, {MEDI,FINA,1}, {MEDI,FINA,3}, {MEDI,FINA,4}, {MEDI,FINA,6}, },
147
148 /* State 4: prev was FINA ALAPH, not willing to join. */
149 { {NONE,NONE,0}, {NONE,ISOL,2}, {MED2,ISOL,1}, {MED2,ISOL,2}, {MED2,FIN2,5}, {MED2,ISOL,6}, },
150
151 /* State 5: prev was FIN2/FIN3 ALAPH, not willing to join. */
152 { {NONE,NONE,0}, {NONE,ISOL,2}, {ISOL,ISOL,1}, {ISOL,ISOL,2}, {ISOL,FIN2,5}, {ISOL,ISOL,6}, },
153
154 /* State 6: prev was DALATH/RISH, not willing to join. */
155 { {NONE,NONE,0}, {NONE,ISOL,2}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,FIN3,5}, {NONE,ISOL,6}, }
156 };
157
158
159 static void
160 nuke_joiners (const hb_ot_shape_plan_t *plan,
161 hb_font_t *font,
162 hb_buffer_t *buffer);
163
164 static void
165 arabic_fallback_shape (const hb_ot_shape_plan_t *plan,
166 hb_font_t *font,
167 hb_buffer_t *buffer);
168
169 static void
170 collect_features_arabic (hb_ot_shape_planner_t *plan)
171 {
172 hb_ot_map_builder_t *map = &plan->map;
173
174 /* For Language forms (in ArabicOT speak), we do the iso/fina/medi/init together,
175 * then rlig and calt each in their own stage. This makes IranNastaliq's ALLAH
176 * ligature work correctly. It's unfortunate though...
177 *
178 * This also makes Arial Bold in Windows7 work. See:
179 * https://bugzilla.mozilla.org/show_bug.cgi?id=644184
180 *
181 * TODO: Add test cases for these two.
182 */
183
184 map->add_gsub_pause (nuke_joiners);
185
186 map->add_global_bool_feature (HB_TAG('c','c','m','p'));
187 map->add_global_bool_feature (HB_TAG('l','o','c','l'));
188
189 map->add_gsub_pause (NULL);
190
191 for (unsigned int i = 0; i < ARABIC_NUM_FEATURES; i++)
192 map->add_feature (arabic_features[i], 1, i < 4 ? F_HAS_FALLBACK : F_NONE); /* The first four features have fallback. */
193
194 map->add_gsub_pause (NULL);
195
196 map->add_feature (HB_TAG('r','l','i','g'), 1, F_GLOBAL|F_HAS_FALLBACK);
197 map->add_gsub_pause (arabic_fallback_shape);
198
199 map->add_global_bool_feature (HB_TAG('c','a','l','t'));
200 map->add_gsub_pause (NULL);
201
202 map->add_global_bool_feature (HB_TAG('m','s','e','t'));
203 }
204
205 #include "hb-ot-shape-complex-arabic-fallback.hh"
206
207 struct arabic_shape_plan_t
208 {
209 ASSERT_POD ();
210
211 /* The "+ 1" in the next array is to accommodate for the "NONE" command,
212 * which is not an OpenType feature, but this simplifies the code by not
213 * having to do a "if (... < NONE) ..." and just rely on the fact that
214 * mask_array[NONE] == 0. */
215 hb_mask_t mask_array[ARABIC_NUM_FEATURES + 1];
216
217 bool do_fallback;
218 arabic_fallback_plan_t *fallback_plan;
219 };
220
221 static void *
222 data_create_arabic (const hb_ot_shape_plan_t *plan)
223 {
224 arabic_shape_plan_t *arabic_plan = (arabic_shape_plan_t *) calloc (1, sizeof (arabic_shape_plan_t));
225 if (unlikely (!arabic_plan))
226 return NULL;
227
228 arabic_plan->do_fallback = plan->props.script == HB_SCRIPT_ARABIC;
229 for (unsigned int i = 0; i < ARABIC_NUM_FEATURES; i++) {
230 arabic_plan->mask_array[i] = plan->map.get_1_mask (arabic_features[i]);
231 if (i < 4)
232 arabic_plan->do_fallback = arabic_plan->do_fallback && plan->map.needs_fallback (arabic_features[i]);
233 }
234
235 return arabic_plan;
236 }
237
238 static void
239 data_destroy_arabic (void *data)
240 {
241 arabic_shape_plan_t *arabic_plan = (arabic_shape_plan_t *) data;
242
243 arabic_fallback_plan_destroy (arabic_plan->fallback_plan);
244
245 free (data);
246 }
247
248 static void
249 arabic_joining (hb_buffer_t *buffer)
250 {
251 unsigned int count = buffer->len;
252 unsigned int prev = (unsigned int) -1, state = 0;
253
254 HB_BUFFER_ALLOCATE_VAR (buffer, arabic_shaping_action);
255
256 /* Check pre-context */
257 if (!(buffer->flags & HB_BUFFER_FLAG_BOT))
258 for (unsigned int i = 0; i < buffer->context_len[0]; i++)
259 {
260 unsigned int this_type = get_joining_type (buffer->context[0][i], buffer->unicode->general_category (buffer->context[0][i]));
261
262 if (unlikely (this_type == JOINING_TYPE_T))
263 continue;
264
265 const arabic_state_table_entry *entry = &arabic_state_table[state][this_type];
266 state = entry->next_state;
267 break;
268 }
269
270 for (unsigned int i = 0; i < count; i++)
271 {
272 unsigned int this_type = get_joining_type (buffer->info[i].codepoint, _hb_glyph_info_get_general_category (&buffer->info[i]));
273
274 if (unlikely (this_type == JOINING_TYPE_T)) {
275 buffer->info[i].arabic_shaping_action() = NONE;
276 continue;
277 }
278
279 const arabic_state_table_entry *entry = &arabic_state_table[state][this_type];
280
281 if (entry->prev_action != NONE && prev != (unsigned int) -1)
282 for (; prev < i; prev++)
283 buffer->info[prev].arabic_shaping_action() = entry->prev_action;
284
285 buffer->info[i].arabic_shaping_action() = entry->curr_action;
286
287 prev = i;
288 state = entry->next_state;
289 }
290
291 if (!(buffer->flags & HB_BUFFER_FLAG_EOT))
292 for (unsigned int i = 0; i < buffer->context_len[1]; i++)
293 {
294 unsigned int this_type = get_joining_type (buffer->context[1][i], buffer->unicode->general_category (buffer->context[1][i]));
295
296 if (unlikely (this_type == JOINING_TYPE_T))
297 continue;
298
299 const arabic_state_table_entry *entry = &arabic_state_table[state][this_type];
300 if (entry->prev_action != NONE && prev != (unsigned int) -1)
301 buffer->info[prev].arabic_shaping_action() = entry->prev_action;
302 break;
303 }
304
305
306 HB_BUFFER_DEALLOCATE_VAR (buffer, arabic_shaping_action);
307 }
308
309 static void
310 setup_masks_arabic (const hb_ot_shape_plan_t *plan,
311 hb_buffer_t *buffer,
312 hb_font_t *font HB_UNUSED)
313 {
314 const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data;
315
316 arabic_joining (buffer);
317 unsigned int count = buffer->len;
318 for (unsigned int i = 0; i < count; i++)
319 buffer->info[i].mask |= arabic_plan->mask_array[buffer->info[i].arabic_shaping_action()];
320 }
321
322
323 static void
324 nuke_joiners (const hb_ot_shape_plan_t *plan HB_UNUSED,
325 hb_font_t *font HB_UNUSED,
326 hb_buffer_t *buffer)
327 {
328 unsigned int count = buffer->len;
329 for (unsigned int i = 0; i < count; i++)
330 if (_hb_glyph_info_is_zwj (&buffer->info[i]))
331 _hb_glyph_info_flip_joiners (&buffer->info[i]);
332 }
333
334 static void
335 arabic_fallback_shape (const hb_ot_shape_plan_t *plan,
336 hb_font_t *font,
337 hb_buffer_t *buffer)
338 {
339 const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data;
340
341 if (!arabic_plan->do_fallback)
342 return;
343
344 retry:
345 arabic_fallback_plan_t *fallback_plan = (arabic_fallback_plan_t *) hb_atomic_ptr_get (&arabic_plan->fallback_plan);
346 if (unlikely (!fallback_plan))
347 {
348 /* This sucks. We need a font to build the fallback plan... */
349 fallback_plan = arabic_fallback_plan_create (plan, font);
350 if (unlikely (!hb_atomic_ptr_cmpexch (&(const_cast<arabic_shape_plan_t *> (arabic_plan))->fallback_plan, NULL, fallback_plan))) {
351 arabic_fallback_plan_destroy (fallback_plan);
352 goto retry;
353 }
354 }
355
356 arabic_fallback_plan_shape (fallback_plan, font, buffer);
357 }
358
359
360 const hb_ot_complex_shaper_t _hb_ot_complex_shaper_arabic =
361 {
362 "arabic",
363 collect_features_arabic,
364 NULL, /* override_features */
365 data_create_arabic,
366 data_destroy_arabic,
367 NULL, /* preprocess_text_arabic */
368 HB_OT_SHAPE_NORMALIZATION_MODE_DEFAULT,
369 NULL, /* decompose */
370 NULL, /* compose */
371 setup_masks_arabic,
372 HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE,
373 true, /* fallback_position */
374 };

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