1 files changed, 164 insertions, 0 deletions
diff --git a/gfx/ots/src/fvar.cc b/gfx/ots/src/fvar.cc
new file mode 100644
index 000000000..6f9b4d6eb
--- /dev/null
+++ b/gfx/ots/src/fvar.cc
@@ -0,0 +1,164 @@
+// 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 "fvar.h"
+
+namespace ots {
+
+// -----------------------------------------------------------------------------
+// OpenTypeFVAR
+// -----------------------------------------------------------------------------
+
+bool OpenTypeFVAR::Parse(const uint8_t* data, size_t length) {
+  Buffer table(data, length);
+  if (!table.ReadU16(&this->majorVersion) ||
+      !table.ReadU16(&this->minorVersion) ||
+      !table.ReadU16(&this->axesArrayOffset) ||
+      !table.ReadU16(&this->reserved) ||
+      !table.ReadU16(&this->axisCount) ||
+      !table.ReadU16(&this->axisSize) ||
+      !table.ReadU16(&this->instanceCount) ||
+      !table.ReadU16(&this->instanceSize)) {
+    return DropVariations("Failed to read table header");
+  }
+  if (this->majorVersion != 1) {
+    return DropVariations("Unknown table version");
+  }
+  if (this->minorVersion > 0) {
+    Warning("Downgrading minor version to 0");
+    this->minorVersion = 0;
+  }
+  if (this->axesArrayOffset > length || this->axesArrayOffset < table.offset()) {
+    return DropVariations("Bad axesArrayOffset");
+  }
+  if (this->reserved != 2) {
+    Warning("Expected reserved=2");
+    this->reserved = 2;
+  }
+  if (this->axisCount == 0) {
+    return DropVariations("No variation axes");
+  }
+  if (this->axisSize != 20) {
+    return DropVariations("Invalid axisSize");
+  }
+  // instanceCount is not validated
+  if (this->instanceSize == this->axisCount * sizeof(Fixed) + 6) {
+    this->instancesHavePostScriptNameID = true;
+  } else if (this->instanceSize == this->axisCount * sizeof(Fixed) + 4) {
+    this->instancesHavePostScriptNameID = false;
+  } else {
+    return DropVariations("Invalid instanceSize");
+  }
+
+  // When we serialize, the axes array will go here, even if it was
+  // originally at a different offset. So we update the axesArrayOffset
+  // field for the header.
+  uint32_t origAxesArrayOffset = this->axesArrayOffset;
+  this->axesArrayOffset = table.offset();
+
+  table.set_offset(origAxesArrayOffset);
+  for (unsigned i = 0; i < this->axisCount; i++) {
+    this->axes.emplace_back();
+    auto& axis = this->axes[i];
+    if (!table.ReadU32(&axis.axisTag) ||
+        !table.ReadS32(&axis.minValue) ||
+        !table.ReadS32(&axis.defaultValue) ||
+        !table.ReadS32(&axis.maxValue) ||
+        !table.ReadU16(&axis.flags) ||
+        !table.ReadU16(&axis.axisNameID)) {
+      return DropVariations("Failed to read axis record");
+    }
+    if (!CheckTag(axis.axisTag)) {
+      return DropVariations("Bad axis tag");
+    }
+    if (!(axis.minValue <= axis.defaultValue && axis.defaultValue <= axis.maxValue)) {
+      return DropVariations("Bad axis value range");
+    }
+    if ((axis.flags & 0xFFFEu) != 0) {
+      Warning("Discarding unknown axis flags");
+      axis.flags &= ~0xFFFEu;
+    }
+    if (axis.axisNameID <= 255 || axis.axisNameID >= 32768) {
+      Warning("Axis nameID out of range");
+      // We don't check that the name actually exists -- assume the client can handle
+      // a missing name when it tries to read the table.
+    }
+  }
+
+  for (unsigned i = 0; i < this->instanceCount; i++) {
+    this->instances.emplace_back();
+    auto& inst = this->instances[i];
+    if (!table.ReadU16(&inst.subfamilyNameID) ||
+        !table.ReadU16(&inst.flags)) {
+      return DropVariations("Failed to read instance record");
+    }
+    inst.coordinates.reserve(this->axisCount);
+    for (unsigned j = 0; j < this->axisCount; j++) {
+      inst.coordinates.emplace_back();
+      auto& coord = inst.coordinates[j];
+      if (!table.ReadS32(&coord)) {
+        return DropVariations("Failed to read instance coordinates");
+      }
+    }
+    if (this->instancesHavePostScriptNameID) {
+      if (!table.ReadU16(&inst.postScriptNameID)) {
+        return DropVariations("Failed to read instance psname ID");
+      }
+    }
+  }
+
+  if (table.remaining()) {
+    return Warning("%zu bytes unparsed", table.remaining());
+  }
+
+  return true;
+}
+
+bool OpenTypeFVAR::Serialize(OTSStream* out) {
+  if (!out->WriteU16(this->majorVersion) ||
+      !out->WriteU16(this->minorVersion) ||
+      !out->WriteU16(this->axesArrayOffset) ||
+      !out->WriteU16(this->reserved) ||
+      !out->WriteU16(this->axisCount) ||
+      !out->WriteU16(this->axisSize) ||
+      !out->WriteU16(this->instanceCount) ||
+      !out->WriteU16(this->instanceSize)) {
+    return Error("Failed to write table");
+  }
+
+  for (unsigned i = 0; i < this->axisCount; i++) {
+    const auto& axis = this->axes[i];
+    if (!out->WriteU32(axis.axisTag) ||
+        !out->WriteS32(axis.minValue) ||
+        !out->WriteS32(axis.defaultValue) ||
+        !out->WriteS32(axis.maxValue) ||
+        !out->WriteU16(axis.flags) ||
+        !out->WriteU16(axis.axisNameID)) {
+      return Error("Failed to write table");
+    }
+  }
+
+  for (unsigned i = 0; i < this->instanceCount; i++) {
+    const auto& inst = this->instances[i];
+    if (!out->WriteU16(inst.subfamilyNameID) ||
+        !out->WriteU16(inst.flags)) {
+      return Error("Failed to write table");
+    }
+    for (unsigned j = 0; j < this->axisCount; j++) {
+      const auto& coord = inst.coordinates[j];
+      if (!out->WriteS32(coord)) {
+        return Error("Failed to write table");
+      }
+    }
+    if (this->instancesHavePostScriptNameID) {
+      if (!out->WriteU16(inst.postScriptNameID)) {
+        return Error("Failed to write table");
+      }
+    }
+  }
+
+  return true;
+}
+
+}  // namespace ots