From da3b7a7ec2cca17d6eb5f5dc3b7759f5284077b0 Mon Sep 17 00:00:00 2001
From: "chappuis.daniel" <chappuis.daniel@92aac97c-a6ce-11dd-a772-7fcde58d38e6>
Date: Thu, 12 Feb 2009 07:45:12 +0000
Subject: [PATCH] git-svn-id:
 https://reactphysics3d.googlecode.com/svn/trunk@90
 92aac97c-a6ce-11dd-a772-7fcde58d38e6

---
 sources/reactphysics3d/mathematics/Quaternion.cpp | 10 ++++++++++
 sources/reactphysics3d/mathematics/Quaternion.h   | 13 +++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/sources/reactphysics3d/mathematics/Quaternion.cpp b/sources/reactphysics3d/mathematics/Quaternion.cpp
index 32453c90..add81b21 100755
--- a/sources/reactphysics3d/mathematics/Quaternion.cpp
+++ b/sources/reactphysics3d/mathematics/Quaternion.cpp
@@ -19,6 +19,7 @@
 
 // Libraries
 #include "Quaternion.h"
+#include <cassert>
 
 // Namespaces
 using namespace reactphysics3d;
@@ -52,4 +53,13 @@ Quaternion::~Quaternion() {
 
 }
 
+// --- Others functions --- //
+
+// Compute the spherical linear interpolation between two quaternions.
+// The t argument has to be such that 0 <= t <= 1
+Quaternion slerp(const Quaternion& quaternion1, const Quaternion& quaternion2, double t) {
+    //TODO : Implement this method
+    assert(t >= 0 && t <= 1);
+}
+
 
diff --git a/sources/reactphysics3d/mathematics/Quaternion.h b/sources/reactphysics3d/mathematics/Quaternion.h
index 59cb96b0..89c57ea0 100644
--- a/sources/reactphysics3d/mathematics/Quaternion.h
+++ b/sources/reactphysics3d/mathematics/Quaternion.h
@@ -61,6 +61,7 @@ class Quaternion
         Quaternion getUnit() const throw (MathematicsException);              // Return the unit quaternion
         Quaternion getConjugate() const;                                      // Return the conjugate quaternion
         Quaternion getInverse() const throw (MathematicsException);           // Return the inverse of the quaternion
+        double scalarProduct(const Quaternion& quaternion);                   // Scalar product between two quaternions
 
         // --- Overloaded operators --- //
         Quaternion operator+(const Quaternion& quaternion) const;             // Overloaded operator for the addition
@@ -71,6 +72,7 @@ class Quaternion
         bool operator==(const Quaternion& quaternion) const;                  // Overloaded operator for equality condition
 };
 
+// --- Inline functions --- //
 
 // Get the value x (inline)
 inline double Quaternion::getX() const {
@@ -161,6 +163,12 @@ inline Quaternion Quaternion::getInverse() const throw(MathematicsException) {
     }
 }
 
+// Scalar product between two quaternions
+// TODO : Test for this method
+inline double Quaternion::scalarProduct(const Quaternion& quaternion) {
+    return (x*quaternion.x + y*quaternion.y + z*quaternion.z + w*quaternion.w);
+}
+
 // Overloaded operator for the addition of two quaternions
 inline Quaternion Quaternion::operator+(const Quaternion& quaternion) const {
     // Return the result quaternion
@@ -204,6 +212,11 @@ inline bool Quaternion::operator==(const Quaternion& quaternion) const {
     return (x == quaternion.x && y == quaternion.y && z == quaternion.z && w == quaternion.w);
 }
 
+// --- Others functions --- //
+
+// Compute the spherical linear interpolation between two quaternions
+Quaternion slerp(const Quaternion& quaternion1, const Quaternion& quaternion2, double t);
+
 } // End of the ReactPhysics3D namespace
 
 #endif