Rename plugins to external

applications/external/airmouse/tracking/util/vectorutils.cc

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2019 Google Inc. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include "vectorutils.h"
+
+namespace cardboard {
+
+// Returns the dot (inner) product of two Vectors.
+double Dot(const Vector<3>& v0, const Vector<3>& v1)
+{
+    return v0[0] * v1[0] + v0[1] * v1[1] + v0[2] * v1[2];
+}
+
+// Returns the dot (inner) product of two Vectors.
+double Dot(const Vector<4>& v0, const Vector<4>& v1)
+{
+    return v0[0] * v1[0] + v0[1] * v1[1] + v0[2] * v1[2] + v0[3] * v1[3];
+}
+
+// Returns the 3-dimensional cross product of 2 Vectors. Note that this is
+// defined only for 3-dimensional Vectors.
+Vector<3> Cross(const Vector<3>& v0, const Vector<3>& v1)
+{
+    return Vector<3>(v0[1] * v1[2] - v0[2] * v1[1], v0[2] * v1[0] - v0[0] * v1[2],
+        v0[0] * v1[1] - v0[1] * v1[0]);
+}
+
+} // namespace cardboard