#pragma once
#include <cmath>

struct double3 {
    union {
        struct {double x, y, z;};
        double data[3]; // For legacy access
    };
    double3() {}
    double3(const double x, const double y, const double z)
        : x(x), y(y), z(z) {}
    double& operator[](int i) {return data[i];}
    const double operator[](int i) const {return data[i];}
    double3& operator=(const double3& a)
    {
        x = a.x;
        y = a.y;
        z = a.z;
        return *this;
    }
    double3& operator+=(const double3& a)
    {
        x += a.x;
        y += a.y;
        z += a.z;
        return *this;
    }
    double3& operator-=(const double3& a)
    {
        x -= a.x;
        y -= a.y;
        z -= a.z;
        return *this;
    }
    double3& operator/=(const double& c)
    {
        x /= c;
        y /= c;
        z /= c;
        return *this;
    }
    double norm2() const
    {
        return x*x + y*y + z*z;
    }
    double norm() const
    {
        return sqrt(x*x + y*y + z*z);
    }
    operator double*() {return data;}
};

inline double3 operator*(const double& c, const double3& a)
{
    return double3(a.x*c, a.y*c, a.z*c);
}

inline double3 operator*(const double3& a, const double& c)
{
    return double3(a.x*c, a.y*c, a.z*c);
}

inline double operator*(const double3& a, const double3& b)
{
    return a.x*b.x+a.y*b.y+a.z*b.z;
}

inline double3 operator/(const double3& a, const double& c)
{
    return double3(a.x/c, a.y/c, a.z/c);
}

inline double3 operator+(const double3& a, const double3& b)
{
    return double3(a.x+b.x, a.y+b.y, a.z+b.z);
}

inline double3 operator-(const double3& a, const double3& b)
{
    return double3(a.x-b.x, a.y-b.y, a.z-b.z);
}