5dd7a15c09
It's better to use '= default;' syntax instead of empty constructor and destructor body. Using '= default;' can help the compiler generate more optimal code. Reported by: PVS-Studio Signed-off-by: Vyacheslav Ivanov <islavaivanov76@gmail.com>
112 lines
4.7 KiB
C++
112 lines
4.7 KiB
C++
#ifndef MATHS_FRUSTUM_CULLING_HPP_
|
|
#define MATHS_FRUSTUM_CULLING_HPP_
|
|
|
|
#include <glm/matrix.hpp>
|
|
|
|
class Frustum {
|
|
public:
|
|
Frustum() = default;
|
|
|
|
void update(glm::mat4 projview);
|
|
bool isBoxVisible(const glm::vec3& minp, const glm::vec3& maxp) const;
|
|
|
|
private:
|
|
enum Planes {
|
|
Left = 0,
|
|
Right,
|
|
Bottom,
|
|
Top,
|
|
Near,
|
|
Far,
|
|
Count,
|
|
Combinations = Count * (Count - 1) / 2
|
|
};
|
|
|
|
template<Planes i, Planes j>
|
|
struct ij2k {
|
|
enum { k = i * (9 - i) / 2 + j - 1 };
|
|
};
|
|
|
|
template<Planes a, Planes b, Planes c>
|
|
glm::vec3 intersection(const glm::vec3* crosses) const;
|
|
|
|
glm::vec4 m_planes[Count];
|
|
glm::vec3 m_points[8];
|
|
};
|
|
|
|
inline void Frustum::update(glm::mat4 m) {
|
|
m = glm::transpose(m);
|
|
m_planes[Left] = m[3] + m[0];
|
|
m_planes[Right] = m[3] - m[0];
|
|
m_planes[Bottom] = m[3] + m[1];
|
|
m_planes[Top] = m[3] - m[1];
|
|
m_planes[Near] = m[3] + m[2];
|
|
m_planes[Far] = m[3] - m[2];
|
|
|
|
glm::vec3 crosses[Combinations] = {
|
|
glm::cross(glm::vec3(m_planes[Left]), glm::vec3(m_planes[Right])),
|
|
glm::cross(glm::vec3(m_planes[Left]), glm::vec3(m_planes[Bottom])),
|
|
glm::cross(glm::vec3(m_planes[Left]), glm::vec3(m_planes[Top])),
|
|
glm::cross(glm::vec3(m_planes[Left]), glm::vec3(m_planes[Near])),
|
|
glm::cross(glm::vec3(m_planes[Left]), glm::vec3(m_planes[Far])),
|
|
glm::cross(glm::vec3(m_planes[Right]), glm::vec3(m_planes[Bottom])),
|
|
glm::cross(glm::vec3(m_planes[Right]), glm::vec3(m_planes[Top])),
|
|
glm::cross(glm::vec3(m_planes[Right]), glm::vec3(m_planes[Near])),
|
|
glm::cross(glm::vec3(m_planes[Right]), glm::vec3(m_planes[Far])),
|
|
glm::cross(glm::vec3(m_planes[Bottom]), glm::vec3(m_planes[Top])),
|
|
glm::cross(glm::vec3(m_planes[Bottom]), glm::vec3(m_planes[Near])),
|
|
glm::cross(glm::vec3(m_planes[Bottom]), glm::vec3(m_planes[Far])),
|
|
glm::cross(glm::vec3(m_planes[Top]), glm::vec3(m_planes[Near])),
|
|
glm::cross(glm::vec3(m_planes[Top]), glm::vec3(m_planes[Far])),
|
|
glm::cross(glm::vec3(m_planes[Near]), glm::vec3(m_planes[Far]))
|
|
};
|
|
|
|
m_points[0] = intersection<Left, Bottom, Near>(crosses);
|
|
m_points[1] = intersection<Left, Top, Near>(crosses);
|
|
m_points[2] = intersection<Right, Bottom, Near>(crosses);
|
|
m_points[3] = intersection<Right, Top, Near>(crosses);
|
|
m_points[4] = intersection<Left, Bottom, Far>(crosses);
|
|
m_points[5] = intersection<Left, Top, Far>(crosses);
|
|
m_points[6] = intersection<Right, Bottom, Far>(crosses);
|
|
m_points[7] = intersection<Right, Top, Far>(crosses);
|
|
|
|
}
|
|
|
|
inline bool Frustum::isBoxVisible(const glm::vec3& minp, const glm::vec3& maxp) const {
|
|
// check box outside/inside of frustum
|
|
for (int i = 0; i < Count; i++) {
|
|
if ((glm::dot(m_planes[i], glm::vec4(minp.x, minp.y, minp.z, 1.0f)) < 0.0) &&
|
|
(glm::dot(m_planes[i], glm::vec4(maxp.x, minp.y, minp.z, 1.0f)) < 0.0) &&
|
|
(glm::dot(m_planes[i], glm::vec4(minp.x, maxp.y, minp.z, 1.0f)) < 0.0) &&
|
|
(glm::dot(m_planes[i], glm::vec4(maxp.x, maxp.y, minp.z, 1.0f)) < 0.0) &&
|
|
(glm::dot(m_planes[i], glm::vec4(minp.x, minp.y, maxp.z, 1.0f)) < 0.0) &&
|
|
(glm::dot(m_planes[i], glm::vec4(maxp.x, minp.y, maxp.z, 1.0f)) < 0.0) &&
|
|
(glm::dot(m_planes[i], glm::vec4(minp.x, maxp.y, maxp.z, 1.0f)) < 0.0) &&
|
|
(glm::dot(m_planes[i], glm::vec4(maxp.x, maxp.y, maxp.z, 1.0f)) < 0.0))
|
|
{
|
|
return false;
|
|
}
|
|
}
|
|
|
|
// check frustum outside/inside box
|
|
int out;
|
|
out = 0; for (int i = 0; i < 8; i++) out += ((m_points[i].x > maxp.x) ? 1 : 0); if (out == 8) return false;
|
|
out = 0; for (int i = 0; i < 8; i++) out += ((m_points[i].x < minp.x) ? 1 : 0); if (out == 8) return false;
|
|
out = 0; for (int i = 0; i < 8; i++) out += ((m_points[i].y > maxp.y) ? 1 : 0); if (out == 8) return false;
|
|
out = 0; for (int i = 0; i < 8; i++) out += ((m_points[i].y < minp.y) ? 1 : 0); if (out == 8) return false;
|
|
out = 0; for (int i = 0; i < 8; i++) out += ((m_points[i].z > maxp.z) ? 1 : 0); if (out == 8) return false;
|
|
out = 0; for (int i = 0; i < 8; i++) out += ((m_points[i].z < minp.z) ? 1 : 0); if (out == 8) return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
template<Frustum::Planes a, Frustum::Planes b, Frustum::Planes c>
|
|
inline glm::vec3 Frustum::intersection(const glm::vec3* crosses) const {
|
|
float D = glm::dot(glm::vec3(m_planes[a]), crosses[ij2k<b, c>::k]);
|
|
glm::vec3 res = glm::mat3(crosses[ij2k<b, c>::k], -crosses[ij2k<a, c>::k], crosses[ij2k<a, b>::k]) *
|
|
glm::vec3(m_planes[a].w, m_planes[b].w, m_planes[c].w);
|
|
return res * (-1.0f / D);
|
|
}
|
|
|
|
#endif // MATHS_FRUSTUM_CULLING_HPP_
|