From 1d26118e32bfec757be1753b30b59bdcffba0257 Mon Sep 17 00:00:00 2001
From: josh <josh@45c1a28c-8058-47b2-ae61-ca45b979098e>
Date: Fri, 16 Jan 2009 18:14:01 +0000
Subject: [PATCH] added cross- and dot-products to util/Vector

git-svn-id: svn://anubis/gvsu@358 45c1a28c-8058-47b2-ae61-ca45b979098e
---
 cs658/final/util/Vector.cc | 16 ++++++++++++++++
 cs658/final/util/Vector.h  |  2 ++
 2 files changed, 18 insertions(+)

diff --git a/cs658/final/util/Vector.cc b/cs658/final/util/Vector.cc
index 91787ff..b81c283 100644
--- a/cs658/final/util/Vector.cc
+++ b/cs658/final/util/Vector.cc
@@ -14,3 +14,19 @@ std::ostream & operator<<(std::ostream & out, const Vector & v)
     out << "[" << v[0] << ", " << v[1] << ", " << v[2] << "]";
     return out;
 }
+
+/* Compute the dot-product of two vectors */
+double operator%(const Vector & v1, const Vector & v2)
+{
+    return v1[0] * v2[0] + v1[1] * v2[1] + v1[2] * v2[2];
+}
+
+/* Compute the cross-product of two vectors */
+Vector operator*(const Vector & v1, const Vector & v2)
+{
+    Vector result;
+    result[0] = v1[1] * v2[2] - v1[2] * v2[1];
+    result[1] = v1[2] * v2[0] - v1[0] * v2[2];
+    result[2] = v1[0] * v2[1] - v1[1] * v2[0];
+    return result;
+}
diff --git a/cs658/final/util/Vector.h b/cs658/final/util/Vector.h
index 8726e92..8128f2c 100644
--- a/cs658/final/util/Vector.h
+++ b/cs658/final/util/Vector.h
@@ -12,6 +12,8 @@ class Vector
         double & operator[](int idx) { return m_array[idx]; }
         double operator[](int idx) const { return m_array[idx]; }
         friend std::ostream & operator<<(std::ostream & out, const Vector & v);
+        friend double operator%(const Vector & v1, const Vector & v2);
+        friend Vector operator*(const Vector & v1, const Vector & v2);
 
     private:
         double  m_array[3];