42 lines
1.1 KiB
C++
42 lines
1.1 KiB
C++
#include "sphere.hpp"
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using glm::normalize;
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using glm::sqrt;
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bool Sphere::intersect(Ray & r, float & t) const {
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float t1, t2;
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float d;
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float a = (r.m_direction.x * r.m_direction.x) +
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(r.m_direction.y * r.m_direction.y) +
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(r.m_direction.z * r.m_direction.z);
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float b = (2 * r.m_direction.x * (r.m_origin.x - m_center.x)) +
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(2 * r.m_direction.y * (r.m_origin.y - m_center.y)) +
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(2 * r.m_direction.z * (r.m_origin.z - m_center.z));
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float c = (m_center.x * m_center.x) +
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(m_center.y * m_center.y) +
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(m_center.z * m_center.z) +
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(r.m_origin.x * r.m_origin.x) +
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(r.m_origin.y * r.m_origin.y) +
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(r.m_origin.z * r.m_origin.z) -
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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);
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d = (b * b) - (4 * a * c);
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if (d >= 0.0f) {
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t1 = (-b - sqrt(d)) / (2 * a);
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t2 = (-b + sqrt(d)) / (2 * a);
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t = t1 < t2 ? t1 : t2;
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return t >= 0.0f;
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} else
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return false;
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}
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vec3 Sphere::normal_at_int(Ray & r, float & t) const {
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vec3 i = vec3(r.m_origin + (t * r.m_direction));
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return normalize(vec3((i - m_center) / m_radius));
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}
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