perp

1 files changed, 7 insertions, 0 deletions

diff --git a/maths.hpp b/maths.hpp
index 74987d3..e432529 100644
--- a/maths.hpp
+++ b/maths.hpp
@@ -261,6 +261,13 @@ struct v3 {
 		return v3<T>(a.y * b.z - a.z * b.y, a.z * b.x - a.x * b.z, a.x * b.y - a.y * b.x);
 	}
 
+	static v3<T> perp(const v3<T>& v) {
+		v3<T> up((T)0, (T)1, (T)0);
+		if (mag_sqrd(v - up) < (T)0.1f)
+			up = v3<T>((T)1, (T)0, (T)0);
+		return cross(v, up);
+	}
+
 	static T mag_sqrd(const v3<T>& v) {
 		return v3<T>::dot(v, v);
 	}