summaryrefslogtreecommitdiffstats
path: root/gfx/ots/src/feat.cc
blob: 19f22c3bc5ab26645fbcc2ea6e9cd0081359b371 (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
// Copyright (c) 2009-2017 The OTS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "feat.h"

#include "name.h"

namespace ots {

bool OpenTypeFEAT::Parse(const uint8_t* data, size_t length) {
  Buffer table(data, length);

  if (!table.ReadU32(&this->version)) {
    return DropGraphite("Failed to read version");
  }
  if (this->version >> 16 != 1 && this->version >> 16 != 2) {
    return DropGraphite("Unsupported table version: %u", this->version >> 16);
  }
  if (!table.ReadU16(&this->numFeat)) {
    return DropGraphite("Failed to read numFeat");
  }
  if (!table.ReadU16(&this->reserved)) {
    return DropGraphite("Failed to read reserved");
  }
  if (this->reserved != 0) {
    Warning("Nonzero reserved");
  }
  if (!table.ReadU32(&this->reserved2)) {
    return DropGraphite("Failed to read valid reserved2");
  }
  if (this->reserved2 != 0) {
    Warning("Nonzero reserved2");
  }

  std::unordered_set<size_t> unverified;
  //this->features.resize(this->numFeat, this);
  for (unsigned i = 0; i < this->numFeat; ++i) {
    this->features.emplace_back(this);
    FeatureDefn& feature = this->features[i];
    if (!feature.ParsePart(table)) {
      return DropGraphite("Failed to read features[%u]", i);
    }
    this->feature_ids.insert(feature.id);
    for (unsigned j = 0; j < feature.numSettings; ++j) {
      size_t offset = feature.offset + j * 4;
      if (offset < feature.offset || offset > length) {
        return DropGraphite("Invalid FeatSettingDefn offset %zu/%zu",
                            offset, length);
      }
      unverified.insert(offset);
        // need to verify that this FeatureDefn points to valid
        // FeatureSettingDefn
    }
  }

  while (table.remaining()) {
    bool used = unverified.erase(table.offset());
    FeatureSettingDefn featSetting(this);
    if (!featSetting.ParsePart(table, used)) {
      return DropGraphite("Failed to read a FeatureSettingDefn");
    }
    featSettings.push_back(featSetting);
  }

  if (!unverified.empty()) {
    return DropGraphite("%zu incorrect offsets into featSettings",
                        unverified.size());
  }
  if (table.remaining()) {
    return Warning("%zu bytes unparsed", table.remaining());
  }
  return true;
}

bool OpenTypeFEAT::Serialize(OTSStream* out) {
  if (!out->WriteU32(this->version) ||
      !out->WriteU16(this->numFeat) ||
      !out->WriteU16(this->reserved) ||
      !out->WriteU32(this->reserved2) ||
      !SerializeParts(this->features, out) ||
      !SerializeParts(this->featSettings, out)) {
    return Error("Failed to write table");
  }
  return true;
}

bool OpenTypeFEAT::IsValidFeatureId(uint32_t id) const {
  return feature_ids.count(id);
}

bool OpenTypeFEAT::FeatureDefn::ParsePart(Buffer& table) {
  OpenTypeNAME* name = static_cast<OpenTypeNAME*>(
      parent->GetFont()->GetTypedTable(OTS_TAG_NAME));
  if (!name) {
    return parent->Error("FeatureDefn: Required name table is missing");
  }

  if (parent->version >> 16 >= 2 && !table.ReadU32(&this->id)) {
    return parent->Error("FeatureDefn: Failed to read id");
  }
  if (parent->version >> 16 == 1)  {
    uint16_t id;
    if (!table.ReadU16(&id)) {
      return parent->Error("FeatureDefn: Failed to read id");
    }
    this->id = id;
  }
  if (!table.ReadU16(&this->numSettings)) {
    return parent->Error("FeatureDefn: Failed to read numSettings");
  }
  if (parent->version >> 16 >= 2) {
    if (!table.ReadU16(&this->reserved)) {
      return parent->Error("FeatureDefn: Failed to read reserved");
    }
    if (this->reserved != 0) {
      parent->Warning("FeatureDefn: Nonzero reserved");
    }
  }
  if (!table.ReadU32(&this->offset)) {
    return parent->Error("FeatureDefn: Failed to read offset");
  }  // validity of offset verified in OpenTypeFEAT::Parse
  if (!table.ReadU16(&this->flags)) {
    return parent->Error("FeatureDefn: Failed to read flags");
  }
  if ((this->flags & RESERVED) != 0) {
    this->flags &= ~RESERVED;
    parent->Warning("FeatureDefn: Nonzero (flags & 0x%x) repaired", RESERVED);
  }
  if (this->flags & HAS_DEFAULT_SETTING &&
      (this->flags & DEFAULT_SETTING) >= this->numSettings) {
    return parent->Error("FeatureDefn: (flags & 0x%x) is set but (flags & 0x%x "
                         "is not a valid setting index", HAS_DEFAULT_SETTING,
                         DEFAULT_SETTING);
  }
  if (!table.ReadU16(&this->label)) {
    return parent->Error("FeatureDefn: Failed to read label");
  }
  if (!name->IsValidNameId(this->label)) {
    if (this->id == 1 && name->IsValidNameId(this->label, true)) {
      parent->Warning("FeatureDefn: Missing NameRecord repaired for feature"
                      " with id=%u, label=%u", this->id, this->label);
    }
    else {
      return parent->Error("FeatureDefn: Invalid label");
    }
  }
  return true;
}

bool OpenTypeFEAT::FeatureDefn::SerializePart(OTSStream* out) const {
  if ((parent->version >> 16 >= 2 && !out->WriteU32(this->id)) ||
      (parent->version >> 16 == 1 &&
       !out->WriteU16(static_cast<uint16_t>(this->id))) ||
      !out->WriteU16(this->numSettings) ||
      (parent->version >> 16 >= 2 && !out->WriteU16(this->reserved)) ||
      !out->WriteU32(this->offset) ||
      !out->WriteU16(this->flags) ||
      !out->WriteU16(this->label)) {
    return parent->Error("FeatureDefn: Failed to write");
  }
  return true;
}

bool OpenTypeFEAT::FeatureSettingDefn::ParsePart(Buffer& table, bool used) {
  OpenTypeNAME* name = static_cast<OpenTypeNAME*>(
      parent->GetFont()->GetTypedTable(OTS_TAG_NAME));
  if (!name) {
    return parent->Error("FeatureSettingDefn: Required name table is missing");
  }

  if (!table.ReadS16(&this->value)) {
    return parent->Error("FeatureSettingDefn: Failed to read value");
  }
  if (!table.ReadU16(&this->label) ||
      (used && !name->IsValidNameId(this->label))) {
    return parent->Error("FeatureSettingDefn: Failed to read valid label");
  }
  return true;
}

bool OpenTypeFEAT::FeatureSettingDefn::SerializePart(OTSStream* out) const {
  if (!out->WriteS16(this->value) ||
      !out->WriteU16(this->label)) {
    return parent->Error("FeatureSettingDefn: Failed to write");
  }
  return true;
}

}  // namespace ots