X-Git-Url: http://git.tdb.fi/?p=libs%2Fmath.git;a=blobdiff_plain;f=source%2Fgeometry%2Fhypersphere.h;h=01aee0e57b22e2791763077aecb3e3193ea35843;hp=ce424e141cb32bbd9e5b8ed1b59cf9aee05ed617;hb=643aa7b2317f88463f66da11e595ebe0f6c9621d;hpb=fe9d42c7cb18bc1db6d278bdc2f8372822d025bf

diff --git a/source/geometry/hypersphere.h b/source/geometry/hypersphere.h
index ce424e1..01aee0e 100644
--- a/source/geometry/hypersphere.h
+++ b/source/geometry/hypersphere.h
@@ -1,6 +1,7 @@
 #ifndef MSP_GEOMETRY_HYPERSPHERE_H_
 #define MSP_GEOMETRY_HYPERSPHERE_H_
 
+#include <cmath>
 #include <msp/linal/vector.h>
 #include "hyperbox.h"
 #include "ray.h"
@@ -79,6 +80,8 @@ inline bool HyperSphere<T, D>::check_intersection(const Ray<T, D> &ray) const
 template<typename T, unsigned D>
 inline unsigned HyperSphere<T, D>::get_intersections(const Ray<T, D> &ray, SurfacePoint<T, D> *points, unsigned size) const
 {
+	using std::sqrt;
+
 	T mid = -inner_product(ray.get_direction(), ray.get_start());
 	LinAl::Vector<T, D> nearest = ray.get_start()+ray.get_direction()*mid;
 	T offset_sq = radius*radius-inner_product(nearest, nearest);