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
|
#ifndef OT_LAYOUT_GSUB_REVERSECHAINSINGLESUBSTFORMAT1_HH
#define OT_LAYOUT_GSUB_REVERSECHAINSINGLESUBSTFORMAT1_HH
#include "Common.hh"
namespace OT {
namespace Layout {
namespace GSUB_impl {
struct ReverseChainSingleSubstFormat1
{
protected:
HBUINT16 format; /* Format identifier--format = 1 */
Offset16To<Coverage>
coverage; /* Offset to Coverage table--from
* beginning of table */
Array16OfOffset16To<Coverage>
backtrack; /* Array of coverage tables
* in backtracking sequence, in glyph
* sequence order */
Array16OfOffset16To<Coverage>
lookaheadX; /* Array of coverage tables
* in lookahead sequence, in glyph
* sequence order */
Array16Of<HBGlyphID16>
substituteX; /* Array of substitute
* GlyphIDs--ordered by Coverage Index */
public:
DEFINE_SIZE_MIN (10);
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
if (!(coverage.sanitize (c, this) && backtrack.sanitize (c, this)))
return_trace (false);
const auto &lookahead = StructAfter<decltype (lookaheadX)> (backtrack);
if (!lookahead.sanitize (c, this))
return_trace (false);
const auto &substitute = StructAfter<decltype (substituteX)> (lookahead);
return_trace (substitute.sanitize (c));
}
bool intersects (const hb_set_t *glyphs) const
{
if (!(this+coverage).intersects (glyphs))
return false;
const auto &lookahead = StructAfter<decltype (lookaheadX)> (backtrack);
unsigned int count;
count = backtrack.len;
for (unsigned int i = 0; i < count; i++)
if (!(this+backtrack[i]).intersects (glyphs))
return false;
count = lookahead.len;
for (unsigned int i = 0; i < count; i++)
if (!(this+lookahead[i]).intersects (glyphs))
return false;
return true;
}
bool may_have_non_1to1 () const
{ return false; }
void closure (hb_closure_context_t *c) const
{
if (!intersects (c->glyphs)) return;
const auto &lookahead = StructAfter<decltype (lookaheadX)> (backtrack);
const auto &substitute = StructAfter<decltype (substituteX)> (lookahead);
+ hb_zip (this+coverage, substitute)
| hb_filter (c->parent_active_glyphs (), hb_first)
| hb_map (hb_second)
| hb_sink (c->output)
;
}
void closure_lookups (hb_closure_lookups_context_t *c) const {}
void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
if (unlikely (!(this+coverage).collect_coverage (c->input))) return;
unsigned int count;
count = backtrack.len;
for (unsigned int i = 0; i < count; i++)
if (unlikely (!(this+backtrack[i]).collect_coverage (c->before))) return;
const auto &lookahead = StructAfter<decltype (lookaheadX)> (backtrack);
count = lookahead.len;
for (unsigned int i = 0; i < count; i++)
if (unlikely (!(this+lookahead[i]).collect_coverage (c->after))) return;
const auto &substitute = StructAfter<decltype (substituteX)> (lookahead);
count = substitute.len;
c->output->add_array (substitute.arrayZ, substitute.len);
}
const Coverage &get_coverage () const { return this+coverage; }
bool would_apply (hb_would_apply_context_t *c) const
{ return c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED; }
bool apply (hb_ot_apply_context_t *c) const
{
TRACE_APPLY (this);
if (unlikely (c->nesting_level_left != HB_MAX_NESTING_LEVEL))
return_trace (false); /* No chaining to this type */
unsigned int index = (this+coverage).get_coverage (c->buffer->cur ().codepoint);
if (likely (index == NOT_COVERED)) return_trace (false);
const auto &lookahead = StructAfter<decltype (lookaheadX)> (backtrack);
const auto &substitute = StructAfter<decltype (substituteX)> (lookahead);
if (unlikely (index >= substitute.len)) return_trace (false);
unsigned int start_index = 0, end_index = 0;
if (match_backtrack (c,
backtrack.len, (HBUINT16 *) backtrack.arrayZ,
match_coverage, this,
&start_index) &&
match_lookahead (c,
lookahead.len, (HBUINT16 *) lookahead.arrayZ,
match_coverage, this,
c->buffer->idx + 1, &end_index))
{
c->buffer->unsafe_to_break_from_outbuffer (start_index, end_index);
if (HB_BUFFER_MESSAGE_MORE && c->buffer->messaging ())
{
c->buffer->message (c->font,
"replacing glyph at %u (reverse chaining substitution)",
c->buffer->idx);
}
c->replace_glyph_inplace (substitute[index]);
if (HB_BUFFER_MESSAGE_MORE && c->buffer->messaging ())
{
c->buffer->message (c->font,
"replaced glyph at %u (reverse chaining substitution)",
c->buffer->idx);
}
/* Note: We DON'T decrease buffer->idx. The main loop does it
* for us. This is useful for preventing surprises if someone
* calls us through a Context lookup. */
return_trace (true);
}
else
{
c->buffer->unsafe_to_concat_from_outbuffer (start_index, end_index);
return_trace (false);
}
}
template<typename Iterator,
hb_requires (hb_is_iterator (Iterator))>
bool serialize_coverage_offset_array (hb_subset_context_t *c, Iterator it) const
{
TRACE_SERIALIZE (this);
auto *out = c->serializer->start_embed<Array16OfOffset16To<Coverage>> ();
if (unlikely (!c->serializer->allocate_size<HBUINT16> (HBUINT16::static_size)))
return_trace (false);
for (auto& offset : it) {
auto *o = out->serialize_append (c->serializer);
if (unlikely (!o) || !o->serialize_subset (c, offset, this))
return_trace (false);
}
return_trace (true);
}
template<typename Iterator, typename BacktrackIterator, typename LookaheadIterator,
hb_requires (hb_is_sorted_source_of (Iterator, hb_codepoint_pair_t)),
hb_requires (hb_is_iterator (BacktrackIterator)),
hb_requires (hb_is_iterator (LookaheadIterator))>
bool serialize (hb_subset_context_t *c,
Iterator coverage_subst_iter,
BacktrackIterator backtrack_iter,
LookaheadIterator lookahead_iter) const
{
TRACE_SERIALIZE (this);
auto *out = c->serializer->start_embed (this);
if (unlikely (!c->serializer->check_success (out))) return_trace (false);
if (unlikely (!c->serializer->embed (this->format))) return_trace (false);
if (unlikely (!c->serializer->embed (this->coverage))) return_trace (false);
if (!serialize_coverage_offset_array (c, backtrack_iter)) return_trace (false);
if (!serialize_coverage_offset_array (c, lookahead_iter)) return_trace (false);
auto *substitute_out = c->serializer->start_embed<Array16Of<HBGlyphID16>> ();
auto substitutes =
+ coverage_subst_iter
| hb_map (hb_second)
;
auto glyphs =
+ coverage_subst_iter
| hb_map_retains_sorting (hb_first)
;
if (unlikely (! c->serializer->check_success (substitute_out->serialize (c->serializer, substitutes))))
return_trace (false);
if (unlikely (!out->coverage.serialize_serialize (c->serializer, glyphs)))
return_trace (false);
return_trace (true);
}
bool subset (hb_subset_context_t *c) const
{
TRACE_SUBSET (this);
const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
const hb_map_t &glyph_map = *c->plan->glyph_map;
const auto &lookahead = StructAfter<decltype (lookaheadX)> (backtrack);
const auto &substitute = StructAfter<decltype (substituteX)> (lookahead);
auto it =
+ hb_zip (this+coverage, substitute)
| hb_filter (glyphset, hb_first)
| hb_filter (glyphset, hb_second)
| hb_map_retains_sorting ([&] (hb_pair_t<hb_codepoint_t, const HBGlyphID16 &> p) -> hb_codepoint_pair_t
{ return hb_pair (glyph_map[p.first], glyph_map[p.second]); })
;
return_trace (bool (it) && serialize (c, it, backtrack.iter (), lookahead.iter ()));
}
};
}
}
}
#endif /* HB_OT_LAYOUT_GSUB_REVERSECHAINSINGLESUBSTFORMAT1_HH */
|
