From 20a34fbc52f8e31eaba1e2849d48cd0f6f20a0a7 Mon Sep 17 00:00:00 2001
From: jiri <jiri>
Date: Sat, 4 Jan 2020 21:58:49 +0000
Subject: [PATCH] *** empty log message ***

---
 quaternion.cc | 36 +++++++++++++++++++++++++++++++-----
 quaternion.h  | 16 +++++++++++-----
 vecmat3.h     |  8 +++++---
 3 files changed, 47 insertions(+), 13 deletions(-)

diff --git a/quaternion.cc b/quaternion.cc
index a937165..b329415 100644
--- a/quaternion.cc
+++ b/quaternion.cc
@@ -24,17 +24,43 @@
 
 
 template<typename T>
-const Quaternion<T> Quaternion<T>::operator*(const Quaternion<T> &rhs) const 
+Quaternion<T> Quaternion<T>::operator*(const Quaternion<T> &rhs) const 
 {
 return Quaternion<T>
 	(
-	this->q[0]*rhs.q[0]-this->q[1]*rhs.q[1]-this->q[2]*rhs.q[2]-this->q[3]*rhs.q[3],
-	this->q[0]*rhs.q[1]+this->q[1]*rhs.q[0]+this->q[2]*rhs.q[3]-this->q[3]*rhs.q[2],
-	this->q[0]*rhs.q[2]+this->q[2]*rhs.q[0]+this->q[3]*rhs.q[1]-this->q[1]*rhs.q[3],
-	this->q[0]*rhs.q[3]+this->q[3]*rhs.q[0]+this->q[1]*rhs.q[2]-this->q[2]*rhs.q[1]
+	q[0]*rhs.q[0]-q[1]*rhs.q[1]-q[2]*rhs.q[2]-q[3]*rhs.q[3],
+	q[0]*rhs.q[1]+q[1]*rhs.q[0]+q[2]*rhs.q[3]-q[3]*rhs.q[2],
+	q[0]*rhs.q[2]+q[2]*rhs.q[0]+q[3]*rhs.q[1]-q[1]*rhs.q[3],
+	q[0]*rhs.q[3]+q[3]*rhs.q[0]+q[1]*rhs.q[2]-q[2]*rhs.q[1]
 	);
 };	
 
+template<typename T>
+Quaternion<T> Quaternion<T>::times_vec3(const T *rhs) const
+{
+return Quaternion<T>
+        (
+       -q[1]*rhs[0]-q[2]*rhs[1]-q[3]*rhs[2],
+        q[0]*rhs[0]+q[2]*rhs[2]-q[3]*rhs[1],
+        q[0]*rhs[1]+q[3]*rhs[0]-q[1]*rhs[2],
+        q[0]*rhs[2]+q[1]*rhs[1]-q[2]*rhs[0]
+        );
+};
+
+template<typename T>
+Quaternion<T> Quaternion<T>::vec3_times(const T *lhs) const
+{
+return Quaternion<T>
+        (
+       -lhs[0]*q[1]-lhs[1]*q[2]-lhs[2]*q[3],
+        lhs[0]*q[0]+lhs[1]*q[3]-lhs[2]*q[2],
+        lhs[1]*q[0]+lhs[2]*q[1]-lhs[0]*q[3],
+        lhs[2]*q[0]+lhs[0]*q[2]-lhs[1]*q[1]
+        );
+};
+
+
+
 
 //basically the same code as in normquat2rotmat, but avoiding extra storage
 template<typename T>
diff --git a/quaternion.h b/quaternion.h
index 3e6d086..1fa7491 100644
--- a/quaternion.h
+++ b/quaternion.h
@@ -21,10 +21,11 @@
 #ifndef _QUATERNION_H_
 #define _QUATERNION_H_
 
-#include <stdlib.h>
+#ifndef AVOID_STDSTREAM
 #include <iostream>
+#endif
+#include <string.h>
 #include <complex>
-#include <cstring>
 #include <math.h>
 
 
@@ -61,9 +62,12 @@ public:
 	const Quaternion operator-() const {Quaternion r(*this); r.q[0]= -r.q[0]; r.q[1]= -r.q[1]; r.q[2]= -r.q[2]; r.q[3]= -r.q[3]; return r;}; //unary minus
 	Quaternion& operator+=(const Quaternion &rhs) {q[0]+=rhs.q[0];q[1]+=rhs.q[1];q[2]+=rhs.q[2];q[3]+=rhs.q[3]; return *this;};
 	Quaternion& operator-=(const Quaternion &rhs) {q[0]-=rhs.q[0];q[1]-=rhs.q[1];q[2]-=rhs.q[2];q[3]-=rhs.q[3]; return *this;};
-	const Quaternion operator+(const Quaternion &rhs) const {return Quaternion(*this) += rhs;};
-	const Quaternion operator-(const Quaternion &rhs) const {return Quaternion(*this) -= rhs;};
-	const Quaternion operator*(const Quaternion &rhs) const;
+	Quaternion operator+(const Quaternion &rhs) const {return Quaternion(*this) += rhs;};
+	Quaternion operator-(const Quaternion &rhs) const {return Quaternion(*this) -= rhs;};
+	Quaternion operator*(const Quaternion &rhs) const; //regular product
+	Quaternion times_vec3(const T *rhs) const; //save flops for quaternions representing vectors
+	Quaternion vec3_times(const T *rhs) const; //save flops for quaternions representing vectors
+	
 	Quaternion& conjugateme(void) {q[1] = -q[1]; q[2] = -q[2]; q[3] = -q[3]; return *this;}
 	Quaternion conjugate(void) const {return Quaternion(*this).conjugateme();}
 	T dot(const Quaternion &rhs) const  {return q[0]*rhs.q[0] + q[1]*rhs.q[1] + q[2]*rhs.q[2] + q[3]*rhs.q[3];};
@@ -84,6 +88,7 @@ public:
 
 	
 //stream I/O
+#ifndef AVOID_STDSTREAM
 template <typename T>
 std::istream& operator>>(std::istream  &s, Quaternion<T> &x)
 {
@@ -102,6 +107,7 @@ s << x.q[2]<<" ";
 s << x.q[3];
 return s;
 }
+#endif
 
 
 
diff --git a/vecmat3.h b/vecmat3.h
index 72cf24c..8d49251 100644
--- a/vecmat3.h
+++ b/vecmat3.h
@@ -24,8 +24,10 @@
 #define _VECMAT3_H_
 
 #include <stdlib.h>
+#ifndef AVOID_STDSTREAM
 #include <iostream>
-#include <cstring>
+#endif
+#include <string.h>
 #include <math.h>
 
 //forward declaration
@@ -169,6 +171,7 @@ public:
 
 	
 //stream I/O
+#ifndef AVOID_STDSTREAM
 template <typename T>
 std::istream& operator>>(std::istream  &s, Vec3<T> &x)
 {
@@ -208,8 +211,7 @@ s << x.q[1][0]<<" "<< x.q[1][1]<<" " << x.q[1][2]<<std::endl;
 s << x.q[2][0]<<" "<< x.q[2][1]<<" " << x.q[2][2]<<std::endl;
 return s;
 }
-
-
+#endif
 
 
 #endif /* _VECMAT3_H_ */