/*
 * Copyright (C) 2026 Richard
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
#ifndef VEC_3
#define VEC_3

#include <array>
#include <cmath>
#include <iostream>

class vec3{
  public:
    std::array<double, 3> e;

    vec3() : e{0, 0, 0} {}
    vec3(double e0, double e1, double e2) : e{e0, e1, e2} {}

    double x() const;
    double y() const;
    double z() const;

    vec3 operator-() const;
    double operator[](int i) const;
    double &operator[](int i);
    vec3& operator+=(const vec3 & other);
    vec3& operator*=(double t);
    vec3& operator/=(double t);
    double length() const;
    double length_squared() const;


};

inline std::ostream &operator<<(std::ostream &out, const vec3 &v);
inline vec3 operator+(const vec3 &u, const vec3 &v);
inline vec3 operator-(const vec3 &u, const vec3 &v);
inline vec3 operator*(const vec3 &u, const vec3 &v);
inline vec3 operator*(double t, const vec3 &v);
inline vec3 operator*(const vec3 &v, double t);
inline vec3 operator/(const vec3 &v, double t);
inline double dot(const vec3 &u, const vec3 &v);
inline vec3 cross(const vec3 &u, const vec3 &v);
inline vec3 unit_vector(const vec3 &v);

#endif