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vec3.h
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#ifndef RAYTRACING_DEV_VEC3_H
#define RAYTRACING_DEV_VEC3_H
#include <iostream>
#include <cmath>
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 sqrt(length_squared());
}
double length_squared() const {
return e[0]*e[0] + e[1]*e[1] + e[2]*e[2];
}
void write_color(std::ostream &out,int samples_per_pixel) {
// Divide the color total by the number of samples
auto scale = 1.0 / samples_per_pixel;
auto r = sqrt(scale * e[0]);
auto g = sqrt(scale * e[1]);
auto b = sqrt(scale * e[2]);
// Write the translated [0,255] value of each color component.
out << static_cast<int>(256 * clamp(r,0.0,0.999)) << ' '
<< static_cast<int>(256 * clamp(g,0.0,0.999)) << ' '
<< static_cast<int>(256 * clamp(b,0.0,0.999)) << '\n';
}
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));
}
public:
double e[3];
};
// 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 t * v;
}
inline vec3 operator/(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 random_in_sphere() {
while (true) {
auto p = vec3::random(-1,1);
if (p.length_squared() >= 1) continue;
return p;
}
}
inline vec3 random_unit_vector() {
auto a = random_double(0,2 * pi);
auto z = random_double(-1,1);
auto r = sqrt(1 - z * z);
return vec3(r * cos(a),r * sin(a),z);
}
inline vec3 random_in_hemisphere(const vec3& normal) {
vec3 in_unit_sphere = random_in_sphere();
if (dot(in_unit_sphere,normal) > 0.0)
return in_unit_sphere;
else
return -in_unit_sphere;
}
inline vec3 reflect(const vec3& v,const vec3& n) {
return v - 2 * dot(v,n) * n;
}
inline vec3 refract(const vec3& uv, const vec3& n, double etai_over_etat) {
auto cos_theta = dot(-uv, n);
vec3 r_out_parallel = etai_over_etat * (uv + cos_theta * n);
vec3 r_out_perp = - sqrt(fabs(1.0 - r_out_parallel.length_squared())) * n;
return r_out_parallel + r_out_perp;
}
inline vec3 random_in_unit_disk() {
while (true) {
auto p = vec3(random_double(-1,1), random_double(-1,1), 0);
if (p.length_squared() >= 1) continue;
return p;
}
}
#endif //RAYTRACING_DEV_VEC3_H