Start implementing wider grenade movement

src/Geometry/Intersect.hs

@@ -49,7 +49,7 @@ intersectSegSurface sp ep p n ss = do
     return xp
 
 isNHS :: Point3 -> Point3 -> Point3 -> Bool
-isNHS p n x = 0 < dot n (x - p)
+isNHS p n x = 0 > dot (p - x) n
 
 intersectSegSegErrorTest :: Point2 -> Point2 -> Point2 -> Point2 -> Maybe Point2
 {-# INLINE intersectSegSegErrorTest #-}