$OpenBSD: patch-src_celmath_intersect_h,v 1.1 2017/04/23 11:09:51 espie Exp $
--- src/celmath/intersect.h.orig	Sun Apr 23 12:13:51 2017
+++ src/celmath/intersect.h	Sun Apr 23 12:14:45 2017
@@ -15,6 +15,7 @@
 #include "ray.h"
 #include "sphere.h"
 #include "ellipsoid.h"
+#include <celmath/mathlib.h>
 
 
 template<class T> bool testIntersection(const Ray3<T>& ray,
