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sphere.h
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sphere.h
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//==================================================================================================
// Written in 2016 by Peter Shirley <[email protected]>
//
// To the extent possible under law, the author(s) have dedicated all copyright and related and
// neighboring rights to this software to the public domain worldwide. This software is distributed
// without any warranty.
//
// You should have received a copy (see file COPYING.txt) of the CC0 Public Domain Dedication along
// with this software. If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
//==================================================================================================
#ifndef SPHEREH
#define SPHEREH
#include "hitable.h"
class sphere: public hitable {
public:
sphere() {}
sphere(vec3 cen, float r, material *m) : center(cen), radius(r), mat_ptr(m) {};
virtual bool hit(const ray& r, float tmin, float tmax, hit_record& rec) const;
virtual bool bounding_box(float t0, float t1, aabb& box) const;
vec3 center;
float radius;
material *mat_ptr;
};
bool sphere::bounding_box(float t0, float t1, aabb& box) const {
box = aabb(center - vec3(radius, radius, radius), center + vec3(radius, radius, radius));
return true;
}
bool sphere::hit(const ray& r, float t_min, float t_max, hit_record& rec) const {
vec3 oc = r.origin() - center;
float a = dot(r.direction(), r.direction());
float b = dot(oc, r.direction());
float c = dot(oc, oc) - radius*radius;
float discriminant = b*b - a*c;
if (discriminant > 0) {
float temp = (-b - sqrt(b*b-a*c))/a;
if (temp < t_max && temp > t_min) {
rec.t = temp;
rec.p = r.point_at_parameter(rec.t);
get_sphere_uv((rec.p-center)/radius, rec.u, rec.v);
rec.normal = (rec.p - center) / radius;
rec.mat_ptr = mat_ptr;
return true;
}
temp = (-b + sqrt(b*b-a*c))/a;
if (temp < t_max && temp > t_min) {
rec.t = temp;
rec.p = r.point_at_parameter(rec.t);
get_sphere_uv((rec.p-center)/radius, rec.u, rec.v);
rec.normal = (rec.p - center) / radius;
rec.mat_ptr = mat_ptr;
return true;
}
}
return false;
}
#endif