1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
|
/*
* Copyright © 2012 Google, Inc.
*
* This is part of HarfBuzz, a text shaping library.
*
* Permission is hereby granted, without written agreement and without
* license or royalty fees, to use, copy, modify, and distribute this
* software and its documentation for any purpose, provided that the
* above copyright notice and the following two paragraphs appear in
* all copies of this software.
*
* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
* Google Author(s): Behdad Esfahbod
*/
#ifndef HB_OT_SHAPE_COMPLEX_ARABIC_FALLBACK_HH
#define HB_OT_SHAPE_COMPLEX_ARABIC_FALLBACK_HH
#include "hb-private.hh"
#include "hb-ot-shape-private.hh"
#include "hb-ot-layout-gsub-table.hh"
static const hb_tag_t arabic_fallback_features[] =
{
HB_TAG('i','n','i','t'),
HB_TAG('m','e','d','i'),
HB_TAG('f','i','n','a'),
HB_TAG('i','s','o','l'),
HB_TAG('r','l','i','g'),
};
/* Same order as the fallback feature array */
enum {
FALLBACK_INIT,
FALLBACK_MEDI,
FALLBACK_FINA,
FALLBACK_ISOL,
FALLBACK_RLIG,
ARABIC_NUM_FALLBACK_FEATURES
};
static OT::SubstLookup *
arabic_fallback_synthesize_lookup_single (const hb_ot_shape_plan_t *plan HB_UNUSED,
hb_font_t *font,
unsigned int feature_index)
{
OT::GlyphID glyphs[SHAPING_TABLE_LAST - SHAPING_TABLE_FIRST + 1];
OT::GlyphID substitutes[SHAPING_TABLE_LAST - SHAPING_TABLE_FIRST + 1];
unsigned int num_glyphs = 0;
/* Populate arrays */
for (hb_codepoint_t u = SHAPING_TABLE_FIRST; u < SHAPING_TABLE_LAST + 1; u++)
{
hb_codepoint_t s = shaping_table[u - SHAPING_TABLE_FIRST][feature_index];
hb_codepoint_t u_glyph, s_glyph;
if (!s ||
!hb_font_get_glyph (font, u, 0, &u_glyph) ||
!hb_font_get_glyph (font, s, 0, &s_glyph) ||
u_glyph == s_glyph ||
u_glyph > 0xFFFF || s_glyph > 0xFFFF)
continue;
glyphs[num_glyphs].set (u_glyph);
substitutes[num_glyphs].set (s_glyph);
num_glyphs++;
}
/* Bubble-sort!
* May not be good-enough for presidential candidate interviews, but good-enough for us... */
hb_bubble_sort (&glyphs[0], num_glyphs, OT::GlyphID::cmp, &substitutes[0]);
OT::Supplier<OT::GlyphID> glyphs_supplier (glyphs, num_glyphs);
OT::Supplier<OT::GlyphID> substitutes_supplier (substitutes, num_glyphs);
/* Each glyph takes four bytes max, and there's some overhead. */
char buf[(SHAPING_TABLE_LAST - SHAPING_TABLE_FIRST + 1) * 4 + 128];
OT::hb_serialize_context_t c (buf, sizeof (buf));
OT::SubstLookup *lookup = c.start_serialize<OT::SubstLookup> ();
bool ret = lookup->serialize_single (&c,
OT::LookupFlag::IgnoreMarks,
glyphs_supplier,
substitutes_supplier,
num_glyphs);
c.end_serialize ();
/* TODO sanitize the results? */
return ret ? c.copy<OT::SubstLookup> () : NULL;
}
static OT::SubstLookup *
arabic_fallback_synthesize_lookup_ligature (const hb_ot_shape_plan_t *plan HB_UNUSED,
hb_font_t *font)
{
OT::GlyphID first_glyphs[ARRAY_LENGTH_CONST (ligature_table)];
unsigned int first_glyphs_indirection[ARRAY_LENGTH_CONST (ligature_table)];
unsigned int ligature_per_first_glyph_count_list[ARRAY_LENGTH_CONST (first_glyphs)];
unsigned int num_first_glyphs = 0;
/* We know that all our ligatures are 2-component */
OT::GlyphID ligature_list[ARRAY_LENGTH_CONST (first_glyphs) * ARRAY_LENGTH_CONST(ligature_table[0].ligatures)];
unsigned int component_count_list[ARRAY_LENGTH_CONST (ligature_list)];
OT::GlyphID component_list[ARRAY_LENGTH_CONST (ligature_list) * 1/* One extra component per ligature */];
unsigned int num_ligatures = 0;
/* Populate arrays */
/* Sort out the first-glyphs */
for (unsigned int first_glyph_idx = 0; first_glyph_idx < ARRAY_LENGTH (first_glyphs); first_glyph_idx++)
{
hb_codepoint_t first_u = ligature_table[first_glyph_idx].first;
hb_codepoint_t first_glyph;
if (!hb_font_get_glyph (font, first_u, 0, &first_glyph))
continue;
first_glyphs[num_first_glyphs].set (first_glyph);
ligature_per_first_glyph_count_list[num_first_glyphs] = 0;
first_glyphs_indirection[num_first_glyphs] = first_glyph_idx;
num_first_glyphs++;
}
hb_bubble_sort (&first_glyphs[0], num_first_glyphs, OT::GlyphID::cmp, &first_glyphs_indirection[0]);
/* Now that the first-glyphs are sorted, walk again, populate ligatures. */
for (unsigned int i = 0; i < num_first_glyphs; i++)
{
unsigned int first_glyph_idx = first_glyphs_indirection[i];
for (unsigned int second_glyph_idx = 0; second_glyph_idx < ARRAY_LENGTH (ligature_table[0].ligatures); second_glyph_idx++)
{
hb_codepoint_t second_u = ligature_table[first_glyph_idx].ligatures[second_glyph_idx].second;
hb_codepoint_t ligature_u = ligature_table[first_glyph_idx].ligatures[second_glyph_idx].ligature;
hb_codepoint_t second_glyph, ligature_glyph;
if (!second_u ||
!hb_font_get_glyph (font, second_u, 0, &second_glyph) ||
!hb_font_get_glyph (font, ligature_u, 0, &ligature_glyph))
continue;
ligature_per_first_glyph_count_list[i]++;
ligature_list[num_ligatures].set (ligature_glyph);
component_count_list[num_ligatures] = 2;
component_list[num_ligatures].set (second_glyph);
num_ligatures++;
}
}
OT::Supplier<OT::GlyphID> first_glyphs_supplier (first_glyphs, num_first_glyphs);
OT::Supplier<unsigned int > ligature_per_first_glyph_count_supplier (ligature_per_first_glyph_count_list, num_first_glyphs);
OT::Supplier<OT::GlyphID> ligatures_supplier (ligature_list, num_ligatures);
OT::Supplier<unsigned int > component_count_supplier (component_count_list, num_ligatures);
OT::Supplier<OT::GlyphID> component_supplier (component_list, num_ligatures);
/* 16 bytes per ligature ought to be enough... */
char buf[ARRAY_LENGTH_CONST (ligature_list) * 16 + 128];
OT::hb_serialize_context_t c (buf, sizeof (buf));
OT::SubstLookup *lookup = c.start_serialize<OT::SubstLookup> ();
bool ret = lookup->serialize_ligature (&c,
OT::LookupFlag::IgnoreMarks,
first_glyphs_supplier,
ligature_per_first_glyph_count_supplier,
num_first_glyphs,
ligatures_supplier,
component_count_supplier,
component_supplier);
c.end_serialize ();
/* TODO sanitize the results? */
return ret ? c.copy<OT::SubstLookup> () : NULL;
}
static OT::SubstLookup *
arabic_fallback_synthesize_lookup (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
unsigned int feature_index)
{
if (feature_index < 4)
return arabic_fallback_synthesize_lookup_single (plan, font, feature_index);
else
return arabic_fallback_synthesize_lookup_ligature (plan, font);
}
struct arabic_fallback_plan_t
{
ASSERT_POD ();
hb_mask_t mask_array[ARABIC_NUM_FALLBACK_FEATURES];
OT::SubstLookup *lookup_array[ARABIC_NUM_FALLBACK_FEATURES];
hb_set_digest_t digest_array[ARABIC_NUM_FALLBACK_FEATURES];
};
static const arabic_fallback_plan_t arabic_fallback_plan_nil = {};
static arabic_fallback_plan_t *
arabic_fallback_plan_create (const hb_ot_shape_plan_t *plan,
hb_font_t *font)
{
arabic_fallback_plan_t *fallback_plan = (arabic_fallback_plan_t *) calloc (1, sizeof (arabic_fallback_plan_t));
if (unlikely (!fallback_plan))
return const_cast<arabic_fallback_plan_t *> (&arabic_fallback_plan_nil);
for (unsigned int i = 0; i < ARABIC_NUM_FALLBACK_FEATURES; i++) {
fallback_plan->mask_array[i] = plan->map.get_1_mask (arabic_fallback_features[i]);
if (fallback_plan->mask_array[i]) {
fallback_plan->lookup_array[i] = arabic_fallback_synthesize_lookup (plan, font, i);
if (fallback_plan->lookup_array[i])
fallback_plan->lookup_array[i]->add_coverage (&fallback_plan->digest_array[i]);
}
}
return fallback_plan;
}
static void
arabic_fallback_plan_destroy (arabic_fallback_plan_t *fallback_plan)
{
if (!fallback_plan || fallback_plan == &arabic_fallback_plan_nil)
return;
for (unsigned int i = 0; i < ARABIC_NUM_FALLBACK_FEATURES; i++)
if (fallback_plan->lookup_array[i])
free (fallback_plan->lookup_array[i]);
free (fallback_plan);
}
static void
arabic_fallback_plan_shape (arabic_fallback_plan_t *fallback_plan,
hb_font_t *font,
hb_buffer_t *buffer)
{
for (unsigned int i = 0; i < ARABIC_NUM_FALLBACK_FEATURES; i++)
if (fallback_plan->lookup_array[i]) {
OT::hb_apply_context_t c (0, font, buffer, fallback_plan->mask_array[i], true/*auto_zwj*/);
fallback_plan->lookup_array[i]->apply_string (&c, &fallback_plan->digest_array[i]);
}
}
#endif /* HB_OT_SHAPE_COMPLEX_ARABIC_FALLBACK_HH */
|
