old-gaming-core/math/Quaternion.h

#ifndef QUATERNION_H
#define QUATERNION_H

#include "math/Vector.h"
#include "utils/StringBuffer.h"

class Quaternion {
    Vector3 xyz;
    float w;

    friend Vector3 operator*(const Vector3& v, const Quaternion& q);

public:
    Quaternion();
    Quaternion(const Vector3& axis, float angle);

    Quaternion lerp(float f, const Quaternion& other) const;
    Quaternion& operator*=(const Quaternion& other);
    Quaternion operator*(const Quaternion& other) const;
    Vector3 operator*(const Vector3& v) const;

    template<int L>
    void toString(StringBuffer<L>& s) const {
        s.append("(");
        s.append(xyz[0]).append(" i + ");
        s.append(xyz[1]).append(" j + ");
        s.append(xyz[2]).append(" k + ");
        s.append(w).append(')');
    }
};

Vector3 operator*(const Vector3& v, const Quaternion& q);

#endif