core: Add Vector dot product

src/core/model/vector.cc

@@ -213,6 +213,12 @@ operator*(double a, const Vector3D& b)
     return Vector3D(b.x * a, b.y * a, b.z * a);
 }
 
+double
+operator*(const Vector3D& a, const Vector3D& b)
+{
+    return a.x * b.x + a.y * b.y + a.z * b.z;
+}
+
 std::ostream&
 operator<<(std::ostream& os, const Vector2D& vector)
 {
@@ -292,4 +298,10 @@ operator*(double a, const Vector2D& b)
     return Vector2D(b.x * a, b.y * a);
 }
 
+double
+operator*(const Vector2D& a, const Vector2D& b)
+{
+    return a.x * b.x + a.y * b.y;
+}
+
 } // namespace ns3

src/core/model/vector.h

@@ -188,6 +188,14 @@ class Vector3D
      * \returns The vector \pname{b} scaled by \pname{a}.
      */
     friend Vector3D operator*(double a, const Vector3D& b);
+
+    /**
+     * Dot product operator.
+     * \param [in] a lhs vector.
+     * \param [in] b rhs vector.
+     * \returns The dot product of \pname{a} and \pname{b}.
+     */
+    friend double operator*(const Vector3D& a, const Vector3D& b);
 };
 
 /**
@@ -333,6 +341,14 @@ class Vector2D
      * \returns The vector \pname{b} scaled by \pname{a}.
      */
     friend Vector2D operator*(double a, const Vector2D& b);
+
+    /**
+     * Dot product operator.
+     * \param [in] a lhs vector.
+     * \param [in] b rhs vector.
+     * \returns The dot product of \pname{a} and \pname{b}.
+     */
+    friend double operator*(const Vector2D& a, const Vector2D& b);
 };
 
 double CalculateDistance(const Vector3D& a, const Vector3D& b);