COSC-3P98-Final-Project/include/render/frustum.h

144 lines
4.8 KiB
C++

/*
* Created by Brett on 08/03/23.
* Licensed under GNU General Public License V3.0
* See LICENSE file for license detail
*/
#ifndef FINALPROJECT_FRUSTUM_H
#define FINALPROJECT_FRUSTUM_H
#include <blt/math/math.h>
#include <render/gl.h>
#include <render/camera.h>
#include <render/ui/graphics.h>
// based on
// http://www.lighthouse3d.com/tutorials/view-frustum-culling/clip-space-approach-extracting-the-planes/
class frustum {
private:
class plane {
private:
float m_A = 0, m_B = 0, m_C = 0, m_D = 0;
public:
plane() = default;
plane(float A, float B, float C, float D): m_A(A), m_B(B), m_C(C), m_D(D) {
normalize();
}
inline void normalize(){
blt::vec3 normal{m_A, m_B, m_C};
auto mag = normal.magnitude();
m_A = m_A / mag;
m_B = m_B / mag;
m_C = m_C / mag;
m_D = m_D / mag;
}
[[nodiscard]] inline float distance(const blt::vec3& point) const {
auto dist = m_A * point.x() + m_B * point.y() + m_C * point.z() + m_D;
return dist;
}
[[nodiscard]] inline float A() const { return m_A; }
[[nodiscard]] inline float B() const { return m_B; }
[[nodiscard]] inline float C() const { return m_C; }
[[nodiscard]] inline float D() const { return m_D; }
};
enum SIDE {
LEFT = 0,
RIGHT = 1,
TOP = 2,
BOTTOM = 3,
NEAR = 4,
FAR = 5,
};
blt::mat4x4 PM;
plane planes[6];
public:
frustum() = default;
void update() {
PM = fp::window::getPerspectiveMatrix() * fp::camera::getViewMatrix();
planes[LEFT] = plane{
PM.m(0, 0) + PM.m(3, 0),
PM.m(0, 1) + PM.m(3, 1),
PM.m(0, 2) + PM.m(3, 2),
PM.m(0, 3) + PM.m(3, 3)
};
planes[RIGHT] = plane{
-PM.m(0, 0) + PM.m(3, 0),
-PM.m(0, 1) + PM.m(3, 1),
-PM.m(0, 2) + PM.m(3, 2),
-PM.m(0, 3) + PM.m(3, 3)
};
planes[BOTTOM] = plane{
PM.m(1, 0) + PM.m(3, 0),
PM.m(1, 1) + PM.m(3, 1),
PM.m(1, 2) + PM.m(3, 2),
PM.m(1, 3) + PM.m(3, 3)
};
planes[TOP] = plane{
-PM.m(1, 0) + PM.m(3, 0),
-PM.m(1, 1) + PM.m(3, 1),
-PM.m(1, 2) + PM.m(3, 2),
-PM.m(1, 3) + PM.m(3, 3)
};
planes[NEAR] = plane{
PM.m(2, 0) + PM.m(3, 0),
PM.m(2, 1) + PM.m(3, 1),
PM.m(2, 2) + PM.m(3, 2),
PM.m(2, 3) + PM.m(3, 3)
};
planes[FAR] = plane{
-PM.m(2, 0) + PM.m(3, 0),
-PM.m(2, 1) + PM.m(3, 1),
-PM.m(2, 2) + PM.m(3, 2),
-PM.m(2, 3) + PM.m(3, 3)
};
fp::graphics::drawPlane(blt::vec4{planes[TOP].A(), planes[TOP].B(), planes[TOP].C(), planes[TOP].D()}, blt::vec3{1.0, 0.0, 0.0});
fp::graphics::drawPlane(blt::vec4{planes[BOTTOM].A(), planes[BOTTOM].B(), planes[BOTTOM].C(), planes[BOTTOM].D()}, blt::vec3{1.0, 0.0, 0.0});
//fp::graphics::drawPlane(blt::vec4{1.0, 1.0, 1.0, 0}, blt::vec3{1.0, 0.0, 0.0});
}
bool pointInside(const blt::vec3& point){
// std::all_of ??
for (auto plane : planes){
// point is outside plane
if (plane.distance(point) < 0) {
return false;
}
}
return true;
}
bool cubeInside(const blt::vec3& start, const blt::vec3& end) {
return pointInside(start) || pointInside(end);
}
static bool isInsideFrustum(const blt::mat4x4& pvm, const blt::vec3& point) {
auto v = pvm * blt::vec4(point);
v = v / v.w();
//blt::logging::trace << v.x() << " " << v.y() << " " << v.z() << "\n";
//return v.x() <= 1 && v.x() >= -1 && v.y() <= 1 && v.y() >= -1 && v.z() <= 1 && v.z() >= -1;
//return (v.x() < -1 || v.x() > 1) && (v.y() < -1 || v.y() > 1) && (v.z() < -1 || v.z() > 1);
// TODO
return true;
}
};
#endif //FINALPROJECT_FRUSTUM_H