Files
PhotonMF/sphere.cpp

30 lines
841 B
C++

#include <cmath>
#include "sphere.hpp"
bool Sphere::intersect(Ray & r, float & t) const {
float d;
float a = (r.m_direction.x * r.m_direction.x) +
(r.m_direction.y * r.m_direction.y) +
(r.m_direction.z * r.m_direction.z);
float b = (2 * r.m_direction.x * (r.m_origin.x - m_center.x)) +
(2 * r.m_direction.y * (r.m_origin.y - m_center.y)) +
(2 * r.m_direction.z * (r.m_origin.z - m_center.z));
float c = (m_center.x * m_center.x) +
(m_center.y * m_center.y) +
(m_center.z * m_center.z) +
(r.m_origin.x * r.m_origin.x) +
(r.m_origin.y * r.m_origin.y) +
(r.m_origin.z * r.m_origin.z) -
2 * ((m_center.x * r.m_origin.x) + (m_center.y * r.m_origin.y) + (m_center.z * r.m_origin.z)) - (m_radius * m_radius);
d = (b * b) - (4 * a * c);
t = (-b - sqrt(d)) / (2 * a);
return d >= 0.0f;
}