+
+struct Plane {
+ glm::vec3 normal;
+ float dist;
+
+ float &A() noexcept { return normal.x; }
+ float &B() noexcept { return normal.y; }
+ float &C() noexcept { return normal.z; }
+ float &D() noexcept { return dist; }
+ float A() const noexcept { return normal.x; }
+ float B() const noexcept { return normal.y; }
+ float C() const noexcept { return normal.z; }
+ float D() const noexcept { return dist; }
+
+ Plane(const glm::vec3 &n, float d)
+ : normal(n), dist(d) { }
+ Plane(const glm::vec4 &abcd)
+ : normal(abcd), dist(abcd.w) { }
+
+ void Normalize() noexcept {
+ const float l = length(normal);
+ normal /= l;
+ dist /= l;
+ }
+};
+
+std::ostream &operator <<(std::ostream &, const Plane &);
+
+struct Frustum {
+ Plane plane[6];
+ Plane &Left() noexcept { return plane[0]; }
+ Plane &Right() noexcept { return plane[1]; }
+ Plane &Bottom() noexcept { return plane[2]; }
+ Plane &Top() noexcept { return plane[3]; }
+ Plane &Near() noexcept { return plane[4]; }
+ Plane &Far() noexcept { return plane[5]; }
+ const Plane &Left() const noexcept { return plane[0]; }
+ const Plane &Right() const noexcept { return plane[1]; }
+ const Plane &Bottom() const noexcept { return plane[2]; }
+ const Plane &Top() const noexcept { return plane[3]; }
+ const Plane &Near() const noexcept { return plane[4]; }
+ const Plane &Far() const noexcept { return plane[5]; }
+
+ /// create frustum from transposed MVP
+ Frustum(const glm::mat4 &mat)
+ : plane{
+ { mat[3] + mat[0] },
+ { mat[3] - mat[0] },
+ { mat[3] + mat[1] },
+ { mat[3] - mat[1] },
+ { mat[3] + mat[2] },
+ { mat[3] - mat[2] },
+ } { }
+
+ void Normalize() noexcept {
+ for (Plane &p : plane) {
+ p.Normalize();
+ }
+ }
+};
+
+std::ostream &operator <<(std::ostream &, const Plane &);
+std::ostream &operator <<(std::ostream &, const Frustum &);
+
+bool CullTest(const AABB &box, const glm::mat4 &) noexcept;
+bool CullTest(const AABB &box, const Frustum &) noexcept;