101 lines
2.2 KiB
C
101 lines
2.2 KiB
C
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#ifndef VEC3_H
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#define VEC3_H
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#include <cmath>
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#include <iostream>
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using std::sqrt;
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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 { return e[0]; }
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double y() const { return e[1]; }
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double z() const { return e[2]; }
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vec3 operator-() const { return vec3(-e[0], -e[1], -e[2]); }
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double operator[](int i) const { return e[i]; }
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double& operator[](int i) { return e[i]; }
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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(length_squared());
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}
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double length_squared() 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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};
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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 unit_vector(const vec3& v) {
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return v / v.length();
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}
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#endif
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