167 lines
4.0 KiB
C++
167 lines
4.0 KiB
C++
#ifndef VEC3_H
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#define VEC3_H
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#include "rayTracer.h"
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class vec3 {
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public:
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double e[3];
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vec3() : e{0, 0, 0} {}
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vec3(double e0, double e1, double e2) : e{e0, e1, e2} {}
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double x() const {
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return e[0];
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}
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double y() const {
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return e[1];
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}
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double z() const {
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return e[2];
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}
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vec3 operator-()const {
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return vec3(-e[0], -e[1], -e[2]);
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}
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double operator[](int i) const {
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return e[i];
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}
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double& operator[](int i) {
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return e[i];
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}
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vec3& operator+=(const vec3& v) {
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e[0] += v.e[0];
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e[1] += v.e[1];
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e[2] += v.e[2];
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return *this;
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}
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vec3& operator*=(double t) {
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e[0] *= t;
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e[1] *= t;
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e[2] *= t;
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return *this;
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}
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vec3& operator/=(double t) {
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return *this *= 1/t;
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}
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double length() const {
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return sqrt(lengthSquared());
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}
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double lengthSquared() const {
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return e[0]*e[0] + e[1]*e[1] + e[2]*e[2];
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}
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bool nearZero() const {
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// Return true if the vector is close to zero in all dimensions.
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auto s = 1e-8;
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return (fabs(e[0]) < s) && (fabs(e[1]) < s) && (fabs(e[2]) < s);
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}
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static vec3 random() {
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return vec3(randomDouble(), randomDouble(), randomDouble());
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}
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static vec3 random(double min, double max) {
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return vec3(randomDouble(min,max), randomDouble(min,max), randomDouble(min,max));
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}
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};
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// point3 is just an alias for vec3, but useful for geometric clarity in the code.
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using point3 = vec3;
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// Vector Utility Functions.
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inline std::ostream& operator<<(std::ostream& out, const vec3& v) {
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return out << v.e[0] << ' ' << v.e[1] << ' ' << v.e[2];
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}
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inline vec3 operator+(const vec3& u, const vec3& v) {
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return vec3(u.e[0] + v.e[0], u.e[1] + v.e[1], u.e[2] + v.e[2]);
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}
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inline vec3 operator-(const vec3& u, const vec3& v) {
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return vec3(u.e[0] - v.e[0], u.e[1] - v.e[1], u.e[2] - v.e[2]);
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}
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inline vec3 operator*(const vec3& u, const vec3& v) {
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return vec3(u.e[0] * v.e[0], u.e[1] * v.e[1], u.e[2] * v.e[2]);
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}
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inline vec3 operator*(double t, const vec3& v) {
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return vec3(t * v.e[0], t * v.e[1], t * v.e[2]);
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}
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inline vec3 operator*(const vec3& v, double t) {
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return t * v;
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}
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inline vec3 operator/(const vec3& v, double t) {
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return (1/t) * v;
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}
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inline double dot(const vec3& u, const vec3& v) {
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return u.e[0] * v.e[0]
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+ u.e[1] * v.e[1]
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+ u.e[2] * v.e[2];
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}
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inline vec3 cross(const vec3& u, const vec3& v) {
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return vec3(u.e[1] * v.e[2] - u.e[2] * v.e[1],
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u.e[2] * v.e[0] - u.e[0] * v.e[2],
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u.e[0] * v.e[1] - u.e[1] * v.e[0]);
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}
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inline vec3 unitVector(const vec3& v) {
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return v / v.length();
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}
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inline vec3 randomInUnitDisk(void) {
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while (true) {
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auto p = vec3(randomDouble(-1, 1), randomDouble(-1, 1), 0);
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if (p.lengthSquared() < 1) return p;
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}
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}
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inline vec3 randomInUnitSphere() {
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while (true) {
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auto p = vec3::random(-1,1);
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if (p.lengthSquared() < 1)
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return p;
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}
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}
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inline vec3 randomUnitVector() {
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return unitVector(randomInUnitSphere());
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}
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inline vec3 randomOnHemisphere(const vec3& normal) {
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vec3 onUnitSphere = randomUnitVector();
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if (dot(onUnitSphere, normal) > 0.0) // In the same hemisphere as the normal
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return onUnitSphere;
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else
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return -onUnitSphere;
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}
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inline vec3 reflect(const vec3& v, const vec3& n) {
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return v - 2 * dot(v, n) * n;
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}
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inline vec3 refract(const vec3& uv, const vec3& n, double etaiOverEtat) {
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auto cosTheta = fmin(dot(-uv, n), 1.0);
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vec3 rOutPerp = etaiOverEtat * (uv + cosTheta * n);
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vec3 rOutParallel = -sqrt(fabs(1.0 - rOutPerp.lengthSquared())) * n;
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return rOutPerp + rOutParallel;
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}
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#endif |