summaryrefslogtreecommitdiffstats
path: root/gfx/harfbuzz/src/OT/Layout/GPOS/PairPosFormat1.hh
blob: 9c9b268889f28c55c43a8e5fa29b71e7d3ad2296 (plain)
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
#ifndef OT_LAYOUT_GPOS_PAIRPOSFORMAT1_HH
#define OT_LAYOUT_GPOS_PAIRPOSFORMAT1_HH

#include "PairSet.hh"

namespace OT {
namespace Layout {
namespace GPOS_impl {


template <typename Types>
struct PairPosFormat1_3
{
  using PairSet = GPOS_impl::PairSet<Types>;
  using PairValueRecord = GPOS_impl::PairValueRecord<Types>;

  protected:
  HBUINT16      format;                 /* Format identifier--format = 1 */
  typename Types::template OffsetTo<Coverage>
                coverage;               /* Offset to Coverage table--from
                                         * beginning of subtable */
  ValueFormat   valueFormat[2];         /* [0] Defines the types of data in
                                         * ValueRecord1--for the first glyph
                                         * in the pair--may be zero (0) */
                                        /* [1] Defines the types of data in
                                         * ValueRecord2--for the second glyph
                                         * in the pair--may be zero (0) */
  Array16Of<typename Types::template OffsetTo<PairSet>>
                pairSet;                /* Array of PairSet tables
                                         * ordered by Coverage Index */
  public:
  DEFINE_SIZE_ARRAY (8 + Types::size, pairSet);

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);

    if (!c->check_struct (this)) return_trace (false);

    unsigned int len1 = valueFormat[0].get_len ();
    unsigned int len2 = valueFormat[1].get_len ();
    typename PairSet::sanitize_closure_t closure =
    {
      valueFormat,
      len1,
      1 + len1 + len2
    };

    return_trace (coverage.sanitize (c, this) && pairSet.sanitize (c, this, &closure));
  }

  bool intersects (const hb_set_t *glyphs) const
  {
    auto &cov = this+coverage;

    if (pairSet.len > glyphs->get_population () * hb_bit_storage ((unsigned) pairSet.len) / 4)
    {
      for (hb_codepoint_t g = HB_SET_VALUE_INVALID; glyphs->next (&g);)
      {
	unsigned i = cov.get_coverage (g);
	if ((this+pairSet[i]).intersects (glyphs, valueFormat))
	  return true;
      }
      return false;
    }

    return
    + hb_zip (cov, pairSet)
    | hb_filter (*glyphs, hb_first)
    | hb_map (hb_second)
    | hb_map ([glyphs, this] (const typename Types::template OffsetTo<PairSet> &_)
              { return (this+_).intersects (glyphs, valueFormat); })
    | hb_any
    ;
  }

  void closure_lookups (hb_closure_lookups_context_t *c) const {}
  void collect_variation_indices (hb_collect_variation_indices_context_t *c) const
  {
    if ((!valueFormat[0].has_device ()) && (!valueFormat[1].has_device ())) return;

    auto it =
    + hb_zip (this+coverage, pairSet)
    | hb_filter (c->glyph_set, hb_first)
    | hb_map (hb_second)
    ;

    if (!it) return;
    + it
    | hb_map (hb_add (this))
    | hb_apply ([&] (const PairSet& _) { _.collect_variation_indices (c, valueFormat); })
    ;
  }

  void collect_glyphs (hb_collect_glyphs_context_t *c) const
  {
    if (unlikely (!(this+coverage).collect_coverage (c->input))) return;
    unsigned int count = pairSet.len;
    for (unsigned int i = 0; i < count; i++)
      (this+pairSet[i]).collect_glyphs (c, valueFormat);
  }

  const Coverage &get_coverage () const { return this+coverage; }

  bool apply (hb_ot_apply_context_t *c) const
  {
    TRACE_APPLY (this);
    hb_buffer_t *buffer = c->buffer;
    unsigned int index = (this+coverage).get_coverage  (buffer->cur().codepoint);
    if (likely (index == NOT_COVERED)) return_trace (false);

    hb_ot_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
    skippy_iter.reset (buffer->idx, 1);
    unsigned unsafe_to;
    if (!skippy_iter.next (&unsafe_to))
    {
      buffer->unsafe_to_concat (buffer->idx, unsafe_to);
      return_trace (false);
    }

    return_trace ((this+pairSet[index]).apply (c, valueFormat, skippy_iter.idx));
  }

  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;

    auto *out = c->serializer->start_embed (*this);
    if (unlikely (!c->serializer->extend_min (out))) return_trace (false);
    out->format = format;
    out->valueFormat[0] = valueFormat[0];
    out->valueFormat[1] = valueFormat[1];
    if (c->plan->flags & HB_SUBSET_FLAGS_NO_HINTING)
    {
      hb_pair_t<unsigned, unsigned> newFormats = compute_effective_value_formats (glyphset);
      out->valueFormat[0] = newFormats.first;
      out->valueFormat[1] = newFormats.second;
    }

    if (c->plan->all_axes_pinned)
    {
      out->valueFormat[0] = out->valueFormat[0].drop_device_table_flags ();
      out->valueFormat[1] = out->valueFormat[1].drop_device_table_flags ();
    }

    hb_sorted_vector_t<hb_codepoint_t> new_coverage;

    + hb_zip (this+coverage, pairSet)
    | hb_filter (glyphset, hb_first)
    | hb_filter ([this, c, out] (const typename Types::template OffsetTo<PairSet>& _)
                 {
                   auto snap = c->serializer->snapshot ();
                   auto *o = out->pairSet.serialize_append (c->serializer);
                   if (unlikely (!o)) return false;
                   bool ret = o->serialize_subset (c, _, this, valueFormat, out->valueFormat);
                   if (!ret)
                   {
                     out->pairSet.pop ();
                     c->serializer->revert (snap);
                   }
                   return ret;
                 },
                 hb_second)
    | hb_map (hb_first)
    | hb_map (glyph_map)
    | hb_sink (new_coverage)
    ;

    out->coverage.serialize_serialize (c->serializer, new_coverage.iter ());

    return_trace (bool (new_coverage));
  }


  hb_pair_t<unsigned, unsigned> compute_effective_value_formats (const hb_set_t& glyphset) const
  {
    unsigned len1 = valueFormat[0].get_len ();
    unsigned len2 = valueFormat[1].get_len ();
    unsigned record_size = HBUINT16::static_size + Value::static_size * (len1 + len2);

    unsigned format1 = 0;
    unsigned format2 = 0;
    for (const auto & _ :
	  + hb_zip (this+coverage, pairSet)
	  | hb_filter (glyphset, hb_first)
	  | hb_map (hb_second)
	)
    {
      const PairSet& set = (this + _);
      const PairValueRecord *record = &set.firstPairValueRecord;

      unsigned count = set.len;
      for (unsigned i = 0; i < count; i++)
      {
        if (record->intersects (glyphset))
        {
          format1 = format1 | valueFormat[0].get_effective_format (record->get_values_1 ());
          format2 = format2 | valueFormat[1].get_effective_format (record->get_values_2 (valueFormat[0]));
        }
        record = &StructAtOffset<const PairValueRecord> (record, record_size);
      }

      if (format1 == valueFormat[0] && format2 == valueFormat[1])
        break;
    }

    return hb_pair (format1, format2);
  }
};


}
}
}

#endif  // OT_LAYOUT_GPOS_PAIRPOSFORMAT1_HH