1 : /*
2 : * Copyright © 2010 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 :
29 :
30 :
31 : /* buffer var allocations */
32 : #define arabic_shaping_action() complex_var_temporary_u16() /* arabic shaping action */
33 :
34 :
35 : /*
36 : * Bits used in the joining tables
37 : */
38 : enum {
39 : JOINING_TYPE_U = 0,
40 : JOINING_TYPE_R = 1,
41 : JOINING_TYPE_D = 2,
42 : JOINING_TYPE_C = JOINING_TYPE_D,
43 : JOINING_GROUP_ALAPH = 3,
44 : JOINING_GROUP_DALATH_RISH = 4,
45 : NUM_STATE_MACHINE_COLS = 5,
46 :
47 : /* We deliberately don't have a JOINING_TYPE_L since that's unused in Unicode. */
48 :
49 : JOINING_TYPE_T = 6,
50 : JOINING_TYPE_X = 7 /* means: use general-category to choose between U or T. */
51 : };
52 :
53 : /*
54 : * Joining types:
55 : */
56 :
57 : #include "hb-ot-shape-complex-arabic-table.hh"
58 :
59 0 : static unsigned int get_joining_type (hb_codepoint_t u, hb_unicode_general_category_t gen_cat)
60 : {
61 : /* TODO Macroize the magic bit operations */
62 :
63 0 : if (likely (hb_in_range<hb_codepoint_t> (u, JOINING_TABLE_FIRST, JOINING_TABLE_LAST))) {
64 0 : unsigned int j_type = joining_table[u - JOINING_TABLE_FIRST];
65 0 : if (likely (j_type != JOINING_TYPE_X))
66 0 : return j_type;
67 : }
68 :
69 : /* Mongolian joining data is not in ArabicJoining.txt yet */
70 0 : if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x1800, 0x18AF)))
71 : {
72 : /* All letters, SIBE SYLLABLE BOUNDARY MARKER, and NIRUGU are D */
73 0 : if (gen_cat == HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER || u == 0x1807 || u == 0x180A)
74 0 : return JOINING_TYPE_D;
75 : }
76 :
77 0 : if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x200C, 0x200D))) {
78 0 : return u == 0x200C ? JOINING_TYPE_U : JOINING_TYPE_C;
79 : }
80 :
81 : 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))) ?
82 0 : JOINING_TYPE_T : JOINING_TYPE_U;
83 : }
84 :
85 :
86 :
87 : static const hb_tag_t arabic_syriac_features[] =
88 : {
89 : HB_TAG('i','n','i','t'),
90 : HB_TAG('m','e','d','i'),
91 : HB_TAG('f','i','n','a'),
92 : HB_TAG('i','s','o','l'),
93 : /* Syriac */
94 : HB_TAG('m','e','d','2'),
95 : HB_TAG('f','i','n','2'),
96 : HB_TAG('f','i','n','3'),
97 : HB_TAG_NONE
98 : };
99 :
100 :
101 : /* Same order as the feature array */
102 : enum {
103 : INIT,
104 : MEDI,
105 : FINA,
106 : ISOL,
107 :
108 : /* Syriac */
109 : MED2,
110 : FIN2,
111 : FIN3,
112 :
113 : NONE,
114 :
115 : COMMON_NUM_FEATURES = 4,
116 : SYRIAC_NUM_FEATURES = 7,
117 : TOTAL_NUM_FEATURES = NONE
118 : };
119 :
120 : static const struct arabic_state_table_entry {
121 : uint8_t prev_action;
122 : uint8_t curr_action;
123 : uint16_t next_state;
124 : } arabic_state_table[][NUM_STATE_MACHINE_COLS] =
125 : {
126 : /* jt_U, jt_R, jt_D, jg_ALAPH, jg_DALATH_RISH */
127 :
128 : /* State 0: prev was U, not willing to join. */
129 : { {NONE,NONE,0}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,ISOL,1}, {NONE,ISOL,6}, },
130 :
131 : /* State 1: prev was R or ISOL/ALAPH, not willing to join. */
132 : { {NONE,NONE,0}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,FIN2,5}, {NONE,ISOL,6}, },
133 :
134 : /* State 2: prev was D/ISOL, willing to join. */
135 : { {NONE,NONE,0}, {INIT,FINA,1}, {INIT,FINA,3}, {INIT,FINA,4}, {INIT,FINA,6}, },
136 :
137 : /* State 3: prev was D/FINA, willing to join. */
138 : { {NONE,NONE,0}, {MEDI,FINA,1}, {MEDI,FINA,3}, {MEDI,FINA,4}, {MEDI,FINA,6}, },
139 :
140 : /* State 4: prev was FINA ALAPH, not willing to join. */
141 : { {NONE,NONE,0}, {MED2,ISOL,1}, {MED2,ISOL,2}, {MED2,FIN2,5}, {MED2,ISOL,6}, },
142 :
143 : /* State 5: prev was FIN2/FIN3 ALAPH, not willing to join. */
144 : { {NONE,NONE,0}, {ISOL,ISOL,1}, {ISOL,ISOL,2}, {ISOL,FIN2,5}, {ISOL,ISOL,6}, },
145 :
146 : /* State 6: prev was DALATH/RISH, not willing to join. */
147 : { {NONE,NONE,0}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,FIN3,5}, {NONE,ISOL,6}, }
148 : };
149 :
150 :
151 :
152 : void
153 0 : _hb_ot_shape_complex_collect_features_arabic (hb_ot_map_builder_t *map, const hb_segment_properties_t *props)
154 : {
155 : /* For Language forms (in ArabicOT speak), we do the iso/fina/medi/init together,
156 : * then rlig and calt each in their own stage. This makes IranNastaliq's ALLAH
157 : * ligature work correctly. It's unfortunate though...
158 : *
159 : * This also makes Arial Bold in Windows7 work. See:
160 : * https://bugzilla.mozilla.org/show_bug.cgi?id=644184
161 : *
162 : * TODO: Add test cases for these two.
163 : */
164 :
165 0 : map->add_bool_feature (HB_TAG('c','c','m','p'));
166 0 : map->add_bool_feature (HB_TAG('l','o','c','l'));
167 :
168 0 : map->add_gsub_pause (NULL, NULL);
169 :
170 0 : unsigned int num_features = props->script == HB_SCRIPT_SYRIAC ? SYRIAC_NUM_FEATURES : COMMON_NUM_FEATURES;
171 0 : for (unsigned int i = 0; i < num_features; i++)
172 0 : map->add_bool_feature (arabic_syriac_features[i], false);
173 :
174 0 : map->add_gsub_pause (NULL, NULL);
175 :
176 0 : map->add_bool_feature (HB_TAG('r','l','i','g'));
177 0 : map->add_gsub_pause (NULL, NULL);
178 :
179 0 : map->add_bool_feature (HB_TAG('c','a','l','t'));
180 0 : map->add_gsub_pause (NULL, NULL);
181 :
182 : /* ArabicOT spec enables 'cswh' for Arabic where as for basic shaper it's disabled by default. */
183 0 : map->add_bool_feature (HB_TAG('c','s','w','h'));
184 0 : }
185 :
186 : bool
187 0 : _hb_ot_shape_complex_prefer_decomposed_arabic (void)
188 : {
189 0 : return FALSE;
190 : }
191 :
192 : void
193 0 : _hb_ot_shape_complex_setup_masks_arabic (hb_ot_map_t *map, hb_buffer_t *buffer)
194 : {
195 0 : unsigned int count = buffer->len;
196 0 : unsigned int prev = 0, state = 0;
197 :
198 0 : HB_BUFFER_ALLOCATE_VAR (buffer, arabic_shaping_action);
199 :
200 0 : for (unsigned int i = 0; i < count; i++)
201 : {
202 0 : unsigned int this_type = get_joining_type (buffer->info[i].codepoint, (hb_unicode_general_category_t) buffer->info[i].general_category());
203 :
204 0 : if (unlikely (this_type == JOINING_TYPE_T)) {
205 0 : buffer->info[i].arabic_shaping_action() = NONE;
206 0 : continue;
207 : }
208 :
209 0 : const arabic_state_table_entry *entry = &arabic_state_table[state][this_type];
210 :
211 0 : if (entry->prev_action != NONE)
212 0 : buffer->info[prev].arabic_shaping_action() = entry->prev_action;
213 :
214 0 : buffer->info[i].arabic_shaping_action() = entry->curr_action;
215 :
216 0 : prev = i;
217 0 : state = entry->next_state;
218 : }
219 :
220 0 : hb_mask_t mask_array[TOTAL_NUM_FEATURES + 1] = {0};
221 0 : unsigned int num_masks = buffer->props.script == HB_SCRIPT_SYRIAC ? SYRIAC_NUM_FEATURES : COMMON_NUM_FEATURES;
222 0 : for (unsigned int i = 0; i < num_masks; i++)
223 0 : mask_array[i] = map->get_1_mask (arabic_syriac_features[i]);
224 :
225 0 : for (unsigned int i = 0; i < count; i++)
226 0 : buffer->info[i].mask |= mask_array[buffer->info[i].arabic_shaping_action()];
227 :
228 0 : HB_BUFFER_DEALLOCATE_VAR (buffer, arabic_shaping_action);
229 0 : }
230 :
231 :
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