1 files changed, 109 insertions, 0 deletions
diff --git a/gfx/ots/src/avar.cc b/gfx/ots/src/avar.cc
new file mode 100644
index 000000000..2a431b1c2
--- /dev/null
+++ b/gfx/ots/src/avar.cc
@@ -0,0 +1,109 @@
+// Copyright (c) 2018 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 "avar.h"
+
+#include "fvar.h"
+
+namespace ots {
+
+// -----------------------------------------------------------------------------
+// OpenTypeAVAR
+// -----------------------------------------------------------------------------
+
+bool OpenTypeAVAR::Parse(const uint8_t* data, size_t length) {
+  Buffer table(data, length);
+  if (!table.ReadU16(&this->majorVersion) ||
+      !table.ReadU16(&this->minorVersion) ||
+      !table.ReadU16(&this->reserved) ||
+      !table.ReadU16(&this->axisCount)) {
+    return Drop("Failed to read table header");
+  }
+  if (this->majorVersion != 1) {
+    return Drop("Unknown table version");
+  }
+  if (this->minorVersion > 0) {
+    // we only know how to serialize version 1.0
+    Warning("Downgrading minor version to 0");
+    this->minorVersion = 0;
+  }
+  if (this->reserved != 0) {
+    Warning("Expected reserved=0");
+    this->reserved = 0;
+  }
+
+  OpenTypeFVAR* fvar = static_cast<OpenTypeFVAR*>(
+      GetFont()->GetTypedTable(OTS_TAG_FVAR));
+  if (!fvar) {
+    return DropVariations("Required fvar table is missing");
+  }
+  if (axisCount != fvar->AxisCount()) {
+    return Drop("Axis count mismatch");
+  }
+
+  for (size_t i = 0; i < this->axisCount; i++) {
+    this->axisSegmentMaps.emplace_back();
+    uint16_t positionMapCount;
+    if (!table.ReadU16(&positionMapCount)) {
+      return Drop("Failed to read position map count");
+    }
+    int foundRequiredMappings = 0;
+    for (size_t j = 0; j < positionMapCount; j++) {
+      AxisValueMap map;
+      if (!table.ReadS16(&map.fromCoordinate) ||
+          !table.ReadS16(&map.toCoordinate)) {
+        return Drop("Failed to read axis value map");
+      }
+      if (map.fromCoordinate < -0x4000 ||
+          map.fromCoordinate > 0x4000 ||
+          map.toCoordinate < -0x4000 ||
+          map.toCoordinate > 0x4000) {
+        return Drop("Axis value map coordinate out of range");
+      }
+      if (j > 0) {
+        if (map.fromCoordinate <= this->axisSegmentMaps[i].back().fromCoordinate ||
+            map.toCoordinate < this->axisSegmentMaps[i].back().toCoordinate) {
+          return Drop("Axis value map out of order");
+        }
+      }
+      if ((map.fromCoordinate == -0x4000 && map.toCoordinate == -0x4000) ||
+          (map.fromCoordinate == 0 && map.toCoordinate == 0) ||
+          (map.fromCoordinate == 0x4000 && map.toCoordinate == 0x4000)) {
+        ++foundRequiredMappings;
+      }
+      this->axisSegmentMaps[i].push_back(map);
+    }
+    if (positionMapCount > 0 && foundRequiredMappings != 3) {
+      return Drop("A required mapping (for -1, 0 or 1) is missing");
+    }
+  }
+
+  return true;
+}
+
+bool OpenTypeAVAR::Serialize(OTSStream* out) {
+  if (!out->WriteU16(this->majorVersion) ||
+      !out->WriteU16(this->minorVersion) ||
+      !out->WriteU16(this->reserved) ||
+      !out->WriteU16(this->axisCount)) {
+    return Error("Failed to write table");
+  }
+
+  for (size_t i = 0; i < this->axisCount; i++) {
+    const auto& axisValueMap = this->axisSegmentMaps[i];
+    if (!out->WriteU16(axisValueMap.size())) {
+      return Error("Failed to write table");
+    }
+    for (size_t j = 0; j < axisValueMap.size(); j++) {
+      if (!out->WriteS16(axisValueMap[j].fromCoordinate) ||
+          !out->WriteS16(axisValueMap[j].toCoordinate)) {
+        return Error("Failed to write table");
+      }
+    }
+  }
+
+  return true;
+}
+
+}  // namespace ots