Rename plugins to external

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

@@ -0,0 +1,76 @@
+/*
+ * 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.
+ */
+#ifndef CARDBOARD_SDK_UTIL_VECTORUTILS_H_
+#define CARDBOARD_SDK_UTIL_VECTORUTILS_H_
+
+//
+// This file contains free functions that operate on Vector instances.
+//
+
+#include <cmath>
+
+#include "vector.h"
+
+namespace cardboard {
+
+// Returns the dot (inner) product of two Vectors.
+double Dot(const Vector<3>& v0, const Vector<3>& v1);
+
+// Returns the dot (inner) product of two Vectors.
+double Dot(const Vector<4>& v0, const Vector<4>& v1);
+
+// 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);
+
+// Returns the square of the length of a Vector.
+template <int Dimension>
+double LengthSquared(const Vector<Dimension>& v) {
+    return Dot(v, v);
+}
+
+// Returns the geometric length of a Vector.
+template <int Dimension>
+double Length(const Vector<Dimension>& v) {
+    return sqrt(LengthSquared(v));
+}
+
+// the Vector untouched and returns false.
+template <int Dimension>
+bool Normalize(Vector<Dimension>* v) {
+    const double len = Length(*v);
+    if(len == 0) {
+        return false;
+    } else {
+        (*v) /= len;
+        return true;
+    }
+}
+
+// Returns a unit-length version of a Vector. If the given Vector has no
+// length, this returns a Zero() Vector.
+template <int Dimension>
+Vector<Dimension> Normalized(const Vector<Dimension>& v) {
+    Vector<Dimension> result = v;
+    if(Normalize(&result))
+        return result;
+    else
+        return Vector<Dimension>::Zero();
+}
+
+} // namespace cardboard
+
+#endif // CARDBOARD_SDK_UTIL_VECTORUTILS_H_