From cfc5d55419a9d42beb42becf2393f4e38ab844bc Mon Sep 17 00:00:00 2001
From: Jack Andersen <jackoalan@gmail.com>
Date: Fri, 15 Apr 2016 17:23:54 -1000
Subject: [PATCH] Const correctness fixes

---
 include/zeus/CQuaternion.hpp | 10 ++++++----
 src/CQuaternion.cpp          | 10 ++++++----
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/include/zeus/CQuaternion.hpp b/include/zeus/CQuaternion.hpp
index b3fe721..4233dd1 100644
--- a/include/zeus/CQuaternion.hpp
+++ b/include/zeus/CQuaternion.hpp
@@ -180,11 +180,11 @@ public:
 
     CQuaternion exp() const;
 
-    float dot(const CQuaternion& quat);
+    float dot(const CQuaternion& quat) const;
 
-    static CQuaternion lerp(CQuaternion& a, CQuaternion& b, double t);
-    static CQuaternion slerp(CQuaternion& a, CQuaternion& b, double t);
-    static CQuaternion nlerp(CQuaternion& a, CQuaternion& b, double t);
+    static CQuaternion lerp(const CQuaternion& a, const CQuaternion& b, double t);
+    static CQuaternion slerp(const CQuaternion& a, const CQuaternion& b, double t);
+    static CQuaternion nlerp(const CQuaternion& a, const CQuaternion& b, double t);
 
     inline float roll() const
     {
@@ -209,6 +209,8 @@ public:
         __m128 mVec128;
         struct { float w, x, y, z; };
     };
+
+    static const CQuaternion skNoRotation;
 };
 
 CQuaternion operator+(float lhs, const CQuaternion& rhs);
diff --git a/src/CQuaternion.cpp b/src/CQuaternion.cpp
index 3b1e96d..6c9635c 100644
--- a/src/CQuaternion.cpp
+++ b/src/CQuaternion.cpp
@@ -3,6 +3,8 @@
 
 namespace zeus
 {
+CQuaternion const CQuaternion::skNoRotation;
+
 void CQuaternion::fromVector3f(const CVector3f& vec)
 {
     float cosX = std::cos(0.5f * vec.x);
@@ -215,22 +217,22 @@ CQuaternion CQuaternion::exp() const
     return ret;
 }
 
-float CQuaternion::dot(const CQuaternion& b)
+float CQuaternion::dot(const CQuaternion& b) const
 {
     return x * b.x + y * b.y + z * b.z + w * b.w;
 }
 
-CQuaternion CQuaternion::lerp(CQuaternion& a,  CQuaternion& b, double t)
+CQuaternion CQuaternion::lerp(const CQuaternion& a,  const CQuaternion& b, double t)
 {
     return (a + t * (b - a));
 }
 
-CQuaternion CQuaternion::nlerp(CQuaternion& a, CQuaternion& b, double t)
+CQuaternion CQuaternion::nlerp(const CQuaternion& a, const CQuaternion& b, double t)
 {
     return lerp(a, b, t).normalized();
 }
 
-CQuaternion CQuaternion::slerp(CQuaternion& a, CQuaternion& b, double t)
+CQuaternion CQuaternion::slerp(const CQuaternion& a, const CQuaternion& b, double t)
 {
     if (t <= 0.0f)
         return a;