quaternion.h

#ifndef QUATERNION_H
#define QUATERNION_H
#include <Eigen/Dense>
#include <vector3G.h>
#include <iostream>
struct Quaternion
{
    GLfloat r; // real part of quaternion
    Vector3Gf im; // imaginary part of quaternion

    Quaternion();

    Quaternion(GLfloat angle, Vector3Gf axis);
    
    Quaternion(Vector3Gf axis);

    GLfloat squaredNorm() const;

    GLfloat norm() const;

    void normalize();

    Quaternion conjugate() const;

    Quaternion inv() const;

    Eigen::Matrix<GLfloat,3,3> toRotationMatrix();

    Quaternion operator+(const Quaternion& q) const;

    Quaternion operator-(const Quaternion& q) const;

    Quaternion operator*(const Quaternion& q) const;

    friend Quaternion operator*(const Quaternion q, const GLfloat& s);
    
    friend Quaternion operator*(const GLfloat& s,const Quaternion q);

    Quaternion operator/(const GLfloat& s) const;

    Quaternion operator/(const Quaternion& q) const;

    friend std::ostream& operator<<(std::ostream& os, const Quaternion& q);  
};

#endif