toytracer/vec3.h
2020-06-07 00:32:31 +02:00

130 lines
3.3 KiB
C++

#ifndef VEC3_H
#define VEC3_H
#include <cmath>
#include <iostream>
#include "util.h"
class Vec3 {
public:
Vec3() : e{0, 0, 0} {}
Vec3(double e0, double e1, double e2) : e{e0, e1, e2} {}
double x() const { return e[0]; }
double y() const { return e[1]; }
double z() const { return e[2]; }
Vec3 operator-() const { return Vec3(-e[0], -e[1], -e[2]); }
double operator[](int i) const { return e[i]; }
double& operator[](int i) { return e[i]; }
Vec3& operator+=(const Vec3& v) {
e[0] += v.e[0];
e[1] += v.e[1];
e[2] += v.e[2];
return *this;
}
Vec3& operator*=(const double t) {
e[0] *= t;
e[1] *= t;
e[2] *= t;
return *this;
}
Vec3& operator/=(const double t) { return *this *= 1 / t; }
double length() const { return std::sqrt(length_squared()); }
double length_squared() const {
return e[0] * e[0] + e[1] * e[1] + e[2] * e[2];
}
inline static Vec3 random() {
return Vec3(random_double(), random_double(), random_double());
}
inline static Vec3 random(double min, double max) {
return Vec3(random_double(min, max), random_double(min, max), random_double(min, max));
}
private:
double e[3];
friend std::ostream& operator<<(std::ostream&, const Vec3&);
friend Vec3 operator+(const Vec3&, const Vec3&);
friend Vec3 operator-(const Vec3&, const Vec3&);
friend Vec3 operator*(const Vec3&, const Vec3&);
friend Vec3 operator*(double, const Vec3&);
friend Vec3 operator*(const Vec3&, double);
friend Vec3 operator/(const Vec3&, double);
friend double dot(const Vec3&, const Vec3&);
friend Vec3 cross(const Vec3&, const Vec3&);
friend Vec3 unit_vector(const Vec3);
};
using Point3 = Vec3;
using Color = Vec3;
// Vec3 utility functions
inline std::ostream& operator<<(std::ostream& out, const Vec3& v) {
return out << v.e[0] << " " << v.e[1] << " " << v.e[2];
}
inline Vec3 operator+(const Vec3& u, const Vec3& v) {
return Vec3(u.e[0] + v.e[0], u.e[1] + v.e[1], u.e[2] + v.e[2]);
}
inline Vec3 operator-(const Vec3& u, const Vec3& v) {
return Vec3(u.e[0] - v.e[0], u.e[1] - v.e[1], u.e[2] - v.e[2]);
}
inline Vec3 operator*(const Vec3& u, const Vec3& v) {
return Vec3(u.e[0] * v.e[0], u.e[1] * v.e[1], u.e[2] * v.e[2]);
}
inline Vec3 operator*(double t, const Vec3& v) {
return Vec3(t * v.e[0], t * v.e[1], t * v.e[2]);
}
inline Vec3 operator*(const Vec3& v, double t) {
return Vec3(t * v.e[0], t * v.e[1], t * v.e[2]);
}
inline Vec3 operator/(const Vec3& v, double t) {
return (1/t) * v;
}
inline double dot(const Vec3 &u, const Vec3& v) {
return u.e[0] * v.e[0]
+ u.e[1] * v.e[1]
+ u.e[2] * v.e[2];
}
inline Vec3 cross(const Vec3 &u, const Vec3& v) {
return Vec3(u.e[1] * v.e[2] - u.e[2] * v.e[1],
u.e[2] * v.e[0] - u.e[0] * v.e[2],
u.e[0] * v.e[1] - u.e[1] * v.e[0]);
}
inline Vec3 unit_vector(Vec3 v) {
return v / v.length();
}
inline Vec3 reflect(const Vec3& v, const Vec3& n) {
return v - 2 * dot(v, n) * n;
}
Vec3 random_in_unit_sphere();
Vec3 random_unit_vector();
Vec3 random_in_hemisphere(const Vec3& normal);
Vec3 refract(const Vec3& uv, const Vec3& n, double etai_over_etat);
Vec3 random_in_unit_disk();
#endif // VEC3_H