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Diffstat (limited to 'gfx/ots/src/feat.cc')
| -rw-r--r-- | gfx/ots/src/feat.cc | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/gfx/ots/src/feat.cc b/gfx/ots/src/feat.cc new file mode 100644 index 000000000..374a7ae9f --- /dev/null +++ b/gfx/ots/src/feat.cc @@ -0,0 +1,193 @@ +// 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) { + if (GetFont()->dropped_graphite) { + return Drop("Skipping Graphite table"); + } + 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 |