Continue to tweak death effects

src/Geometry/Vector.hs

@@ -68,6 +68,13 @@ dotV (V2 x y) (V2 z w) = x*z + y*w
 argV :: Point2 -> Float
 {-# INLINE argV #-}
 argV (V2 x y) = normalizeAngle $ atan2 y x
+
+{- | Given vector, returns the angle, anticlockwise from +ve x-axis, in radians.  
+ Returns Nothing for a 0 0 vector. -}
+safeArgV :: Point2 -> Maybe Float
+{-# INLINE safeArgV #-}
+safeArgV (V2 0 0) = Nothing
+safeArgV v = Just $ argV v
 {- | Determinant of the matrix formed by two vectors.  -}
 detV :: Point2 -> Point2 -> Float
 {-# INLINE detV #-}