summaryrefslogtreecommitdiff
path: root/thirdparty/harfbuzz/src/OT/Layout/GPOS/MarkLigPosFormat1.hh
blob: 4382aa6c6cb3d4a1e4f1304c8d5c8acf4d7dea7a (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
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_GPOS_MARKLIGPOSFORMAT1_HH
#define OT_LAYOUT_GPOS_MARKLIGPOSFORMAT1_HH

namespace OT {
namespace Layout {
namespace GPOS_impl {

typedef AnchorMatrix LigatureAttach;    /* component-major--
                                         * in order of writing direction--,
                                         * mark-minor--
                                         * ordered by class--zero-based. */

/* Array of LigatureAttach tables ordered by LigatureCoverage Index */
struct LigatureArray : List16OfOffset16To<LigatureAttach>
{
  template <typename Iterator,
            hb_requires (hb_is_iterator (Iterator))>
  bool subset (hb_subset_context_t *c,
               Iterator             coverage,
               unsigned             class_count,
               const hb_map_t      *klass_mapping) const
  {
    TRACE_SUBSET (this);
    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();

    auto *out = c->serializer->start_embed (this);
    if (unlikely (!c->serializer->extend_min (out)))  return_trace (false);

    for (const auto _ : + hb_zip (coverage, *this)
                  | hb_filter (glyphset, hb_first))
    {
      auto *matrix = out->serialize_append (c->serializer);
      if (unlikely (!matrix)) return_trace (false);

      const LigatureAttach& src = (this + _.second);
      auto indexes =
          + hb_range (src.rows * class_count)
          | hb_filter ([=] (unsigned index) { return klass_mapping->has (index % class_count); })
          ;
      matrix->serialize_subset (c,
                                _.second,
                                this,
                                src.rows,
                                indexes);
    }
    return_trace (this->len);
  }
};

struct MarkLigPosFormat1
{
  protected:
  HBUINT16      format;                 /* Format identifier--format = 1 */
  Offset16To<Coverage>
                markCoverage;           /* Offset to Mark Coverage table--from
                                         * beginning of MarkLigPos subtable */
  Offset16To<Coverage>
                ligatureCoverage;       /* Offset to Ligature Coverage
                                         * table--from beginning of MarkLigPos
                                         * subtable */
  HBUINT16      classCount;             /* Number of defined mark classes */
  Offset16To<MarkArray>
                markArray;              /* Offset to MarkArray table--from
                                         * beginning of MarkLigPos subtable */
  Offset16To<LigatureArray>
                ligatureArray;          /* Offset to LigatureArray table--from
                                         * beginning of MarkLigPos subtable */
  public:
  DEFINE_SIZE_STATIC (12);

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (c->check_struct (this) &&
                  markCoverage.sanitize (c, this) &&
                  ligatureCoverage.sanitize (c, this) &&
                  markArray.sanitize (c, this) &&
                  ligatureArray.sanitize (c, this, (unsigned int) classCount));
  }

  bool intersects (const hb_set_t *glyphs) const
  {
    return (this+markCoverage).intersects (glyphs) &&
           (this+ligatureCoverage).intersects (glyphs);
  }

  void closure_lookups (hb_closure_lookups_context_t *c) const {}

  void collect_variation_indices (hb_collect_variation_indices_context_t *c) const
  {
    + hb_zip (this+markCoverage, this+markArray)
    | hb_filter (c->glyph_set, hb_first)
    | hb_map (hb_second)
    | hb_apply ([&] (const MarkRecord& record) { record.collect_variation_indices (c, &(this+markArray)); })
    ;

    hb_map_t klass_mapping;
    Markclass_closure_and_remap_indexes (this+markCoverage, this+markArray, *c->glyph_set, &klass_mapping);

    unsigned ligcount = (this+ligatureArray).len;
    auto lig_iter =
    + hb_zip (this+ligatureCoverage, hb_range (ligcount))
    | hb_filter (c->glyph_set, hb_first)
    | hb_map (hb_second)
    ;

    const LigatureArray& lig_array = this+ligatureArray;
    for (const unsigned i : lig_iter)
    {
      hb_sorted_vector_t<unsigned> lig_indexes;
      unsigned row_count = lig_array[i].rows;
      for (unsigned row : + hb_range (row_count))
      {
        + hb_range ((unsigned) classCount)
        | hb_filter (klass_mapping)
        | hb_map ([&] (const unsigned col) { return row * (unsigned) classCount + col; })
        | hb_sink (lig_indexes)
        ;
      }

      lig_array[i].collect_variation_indices (c, lig_indexes.iter ());
    }
  }

  void collect_glyphs (hb_collect_glyphs_context_t *c) const
  {
    if (unlikely (!(this+markCoverage).collect_coverage (c->input))) return;
    if (unlikely (!(this+ligatureCoverage).collect_coverage (c->input))) return;
  }

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

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

    /* Now we search backwards for a non-mark glyph */
    hb_ot_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
    skippy_iter.reset (buffer->idx, 1);
    skippy_iter.set_lookup_props (LookupFlag::IgnoreMarks);
    unsigned unsafe_from;
    if (!skippy_iter.prev (&unsafe_from))
    {
      buffer->unsafe_to_concat_from_outbuffer (unsafe_from, buffer->idx + 1);
      return_trace (false);
    }

    /* Checking that matched glyph is actually a ligature by GDEF is too strong; disabled */
    //if (!_hb_glyph_info_is_ligature (&buffer->info[skippy_iter.idx])) { return_trace (false); }

    unsigned int j = skippy_iter.idx;
    unsigned int lig_index = (this+ligatureCoverage).get_coverage  (buffer->info[j].codepoint);
    if (lig_index == NOT_COVERED)
    {
      buffer->unsafe_to_concat_from_outbuffer (skippy_iter.idx, buffer->idx + 1);
      return_trace (false);
    }

    const LigatureArray& lig_array = this+ligatureArray;
    const LigatureAttach& lig_attach = lig_array[lig_index];

    /* Find component to attach to */
    unsigned int comp_count = lig_attach.rows;
    if (unlikely (!comp_count))
    {
      buffer->unsafe_to_concat_from_outbuffer (skippy_iter.idx, buffer->idx + 1);
      return_trace (false);
    }

    /* We must now check whether the ligature ID of the current mark glyph
     * is identical to the ligature ID of the found ligature.  If yes, we
     * can directly use the component index.  If not, we attach the mark
     * glyph to the last component of the ligature. */
    unsigned int comp_index;
    unsigned int lig_id = _hb_glyph_info_get_lig_id (&buffer->info[j]);
    unsigned int mark_id = _hb_glyph_info_get_lig_id (&buffer->cur());
    unsigned int mark_comp = _hb_glyph_info_get_lig_comp (&buffer->cur());
    if (lig_id && lig_id == mark_id && mark_comp > 0)
      comp_index = hb_min (comp_count, _hb_glyph_info_get_lig_comp (&buffer->cur())) - 1;
    else
      comp_index = comp_count - 1;

    return_trace ((this+markArray).apply (c, mark_index, comp_index, lig_attach, classCount, j));
  }

  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;

    hb_map_t klass_mapping;
    Markclass_closure_and_remap_indexes (this+markCoverage, this+markArray, glyphset, &klass_mapping);

    if (!klass_mapping.get_population ()) return_trace (false);
    out->classCount = klass_mapping.get_population ();

    auto mark_iter =
    + hb_zip (this+markCoverage, this+markArray)
    | hb_filter (glyphset, hb_first)
    ;

    auto new_mark_coverage =
    + mark_iter
    | hb_map_retains_sorting (hb_first)
    | hb_map_retains_sorting (glyph_map)
    ;

    if (!out->markCoverage.serialize_serialize (c->serializer, new_mark_coverage))
      return_trace (false);

    out->markArray.serialize_subset (c, markArray, this,
                                     (this+markCoverage).iter (),
                                     &klass_mapping);

    auto new_ligature_coverage =
    + hb_iter (this + ligatureCoverage)
    | hb_filter (glyphset)
    | hb_map_retains_sorting (glyph_map)
    ;

    if (!out->ligatureCoverage.serialize_serialize (c->serializer, new_ligature_coverage))
      return_trace (false);

    out->ligatureArray.serialize_subset (c, ligatureArray, this,
                                         hb_iter (this+ligatureCoverage), classCount, &klass_mapping);

    return_trace (true);
  }

};

}
}
}

#endif /* OT_LAYOUT_GPOS_MARKLIGPOSFORMAT1_HH */