X-Git-Url: http://git.localhorst.tv/?a=blobdiff_plain;f=src%2Fgeometry%2Fgeometry.cpp;h=1c1bfd61655bf8e2225d681c35984798f400da56;hb=9932ee17a767b64cb52c213e133c6b91a90a8dd2;hp=8deed860dc0622825153fd07873240bcac91c0a1;hpb=0e069351615f1315a5c7103fe5c849a242f72683;p=gong.git

diff --git a/src/geometry/geometry.cpp b/src/geometry/geometry.cpp
index 8deed86..1c1bfd6 100644
--- a/src/geometry/geometry.cpp
+++ b/src/geometry/geometry.cpp
@@ -217,6 +217,16 @@ std::ostream &operator <<(std::ostream &out, const Plane &plane) {
 	return out << "Plane(" << plane.normal << ", " << plane.dist << ')';
 }
 
+float Distance(const glm::vec3 &point, const Plane &plane) {
+	return std::abs(SignedDistance(point, plane));
+}
+
+float SignedDistance(const glm::vec3 &point, const Plane &plane) {
+	return (
+		plane.A() * point.x + plane.B() * point.y + plane.C() * point.z + plane.D()
+	) / glm::length(plane.normal);
+}
+
 std::ostream &operator <<(std::ostream &out, const Frustum &frustum) {
 	return out << "Frustum(" << std::endl
 		<< "\tleft:   " << frustum.plane[0] << std::endl
@@ -277,6 +287,35 @@ bool CullTest(const AABB &box, const Frustum &frustum) noexcept {
 	}
 	return false;
 }
+
+std::ostream &operator <<(std::ostream &out, const Sphere &s) {
+	return out << "Sphere(" << s.origin << ", " << s.radius << ')';
+}
+
+bool Intersection(
+	const Sphere &sphere,
+	const Plane &plane,
+	float &dist,
+	glm::vec3 &norm
+) noexcept {
+	float sig_dist = SignedDistance(sphere.origin, plane);
+	dist = sphere.radius - std::abs(sig_dist);
+	if (dist > 0.0f) {
+		norm = sig_dist > 0.0f ? plane.normal : -plane.normal;
+		return true;
+	} else {
+		return false;
+	}
+}
+
+bool Intersection(
+	const Sphere &sphere,
+	const Plane &plane,
+	float &dist
+) noexcept {
+	dist = sphere.radius - SignedDistance(sphere.origin, plane);
+	return dist > 0.0f;
 }
 
 }
+}