#ifndef BLANK_GEOMETRY_PRIMITIVE_HPP_
#define BLANK_GEOMETRY_PRIMITIVE_HPP_
+#include "../graphics/glm.hpp"
+
#include <algorithm>
-#include <glm/glm.hpp>
+#include <iosfwd>
+#include <glm/gtx/norm.hpp>
namespace blank {
/// return distance between origin and farthest vertex
float OriginRadius() const noexcept {
- glm::vec3 high(glm::max(abs(min), abs(max)));
- return length(high);
+ glm::vec3 high(glm::max(glm::abs(min), glm::abs(max)));
+ return glm::length(high);
}
};
+std::ostream &operator <<(std::ostream &, const AABB &);
+
+// TODO: this should really use setters/getters for dir and inv_dir so
+// manipulating code doesn't "forget" to call Update()
struct Ray {
glm::vec3 orig;
glm::vec3 dir;
+
+ glm::vec3 inv_dir;
+
+ void Update() noexcept {
+ inv_dir = 1.0f / dir;
+ }
+
+ /// get shortest distance of this ray's line to given point
+ float Distance(const glm::vec3 &point) const noexcept {
+ // d = |(x2-x1)×(x1-x0)|/|x2-x1|
+ // where x0 is point, and x1 and x2 are points on the line
+ // for derivation, see http://mathworld.wolfram.com/Point-LineDistance3-Dimensional.html
+ // x1 = orig
+ // x2-x1 = dir, which means |x2-x1| is 1.0
+ return glm::length(glm::cross(dir, orig - point));
+ }
+ float DistanceSquared(const glm::vec3 &point) const noexcept {
+ return glm::length2(glm::cross(dir, orig - point));
+ }
};
+std::ostream &operator <<(std::ostream &, const Ray &);
+
+/// axis aligned boolean ray/box intersection test
+/// if true, dist constains distance from ray's origin to intersection point
+bool Intersection(
+ const Ray &,
+ const AABB &,
+ float &dist) noexcept;
+
+/// detailed oriented ray/box intersection test
bool Intersection(
const Ray &,
const AABB &,
float *dist = nullptr,
glm::vec3 *normal = nullptr) noexcept;
+/// matrices may translate and rotate, but must not scale/shear/etc
+/// (basically the first three columns must have unit length)
bool Intersection(
const AABB &a_box,
const glm::mat4 &a_m,
float &depth,
glm::vec3 &normal) noexcept;
-bool CullTest(const AABB &box, const glm::mat4 &MVP) noexcept;
+
+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) { }
+ explicit Plane(const glm::vec4 &abcd)
+ : normal(abcd), dist(abcd.w) { }
+
+ void Normalize() noexcept {
+ const float l = glm::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
+ explicit Frustum(const glm::mat4 &mat)
+ : plane{
+ Plane{ mat[3] + mat[0] },
+ Plane{ mat[3] - mat[0] },
+ Plane{ mat[3] + mat[1] },
+ Plane{ mat[3] - mat[1] },
+ Plane{ mat[3] + mat[2] },
+ Plane{ 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;
}