X-Git-Url: http://git.localhorst.tv/?a=blobdiff_plain;f=src%2Fgeometry%2Fprimitive.hpp;h=76064c1b13f8ce2e26ef26075e3e44b8dce9c750;hb=dcd54cacda98c2c0f7cf0c7a9131fb858d8ee10a;hp=da4c37f1e03296d254d55f051d5e199f94132a9c;hpb=1e93bfb5089737f6b6d8fdd2f17260944fca44b2;p=blank.git

diff --git a/src/geometry/primitive.hpp b/src/geometry/primitive.hpp
index da4c37f..76064c1 100644
--- a/src/geometry/primitive.hpp
+++ b/src/geometry/primitive.hpp
@@ -1,9 +1,11 @@
 #ifndef BLANK_GEOMETRY_PRIMITIVE_HPP_
 #define BLANK_GEOMETRY_PRIMITIVE_HPP_
 
+#include "../graphics/glm.hpp"
+
 #include <algorithm>
 #include <iosfwd>
-#include <glm/glm.hpp>
+#include <glm/gtx/norm.hpp>
 
 
 namespace blank {
@@ -24,20 +26,49 @@ struct AABB {
 
 	/// 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 &,
@@ -75,7 +106,7 @@ struct Plane {
 	: normal(abcd), dist(abcd.w) { }
 
 	void Normalize() noexcept {
-		const float l = length(normal);
+		const float l = glm::length(normal);
 		normal /= l;
 		dist /= l;
 	}