Files
PhotonMF/disk.cpp

44 lines
1003 B
C++

#include <iostream>
#include <cassert>
#include "disk.hpp"
#include "sampling.hpp"
using glm::vec2;
using glm::cos;
using glm::sin;
using glm::dot;
using glm::distance;
using glm::cross;
using glm::abs;
bool Disk::intersect(Ray & r, float & t) const {
float _t;
vec3 i_pos, i_vec;
if (Plane::intersect(r, _t)) {
i_pos = r.m_origin + (_t * r.m_direction);
i_vec = i_pos - m_point;
t = _t;
return dot(i_vec, i_vec) <= (m_radius * m_radius);
}
return false;
}
vec3 Disk::sample_at_surface() const {
float theta = random01() * pi2;
float r = random01() * m_radius;
vec3 nt, nb;
create_coords_system(m_normal, nt, nb);
float x = m_point.x + (r * cos(theta) * nt.x) + (r * sin(theta) * nb.x);
float y = m_point.y + (r * cos(theta) * nt.y) + (r * sin(theta) * nb.y);
float z = m_point.z + (r * cos(theta) * nt.z) + (r * sin(theta) * nb.z);
return vec3(x, y, z);
}
void Disk::calculate_inv_area() {
m_inv_area = 1.0f / pi<float>() * (m_radius * m_radius);
}