From 5bcf5a18cda4d712ca177f4ad43fea690f31e6f9 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sat, 22 Nov 2014 11:41:13 +0200
Subject: [PATCH] Avoid division by zero in HalfSpace::get_intersections

---
 source/geometry/halfspace.h | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/source/geometry/halfspace.h b/source/geometry/halfspace.h
index f671629..4adc0df 100644
--- a/source/geometry/halfspace.h
+++ b/source/geometry/halfspace.h
@@ -63,7 +63,12 @@ inline bool HalfSpace<T, D>::contains(const LinAl::Vector<T, D> &point) const
 template<typename T, unsigned D>
 inline unsigned HalfSpace<T, D>::get_intersections(const Ray<T, D> &ray, SurfacePoint<T, D> *points, unsigned size) const
 {
-	T x = -inner_product(ray.get_start(), normal)/inner_product(ray.get_direction(), normal);
+	T d = inner_product(ray.get_start(), normal);
+	T c = inner_product(ray.get_direction(), normal);
+	if(c==T(0))
+		return 0;
+
+	T x = -d/c;
 	if(ray.check_limits(x))
 	{
 		if(points && size>0)
-- 
2.45.2