+-- | The Face module just contains the definition of the 'Face' data
+-- type and its two typeclass instances.
module Face
where
" v2: " ++ (show (v2 f)) ++ "\n" ++
" v3: " ++ (show (v3 f)) ++ "\n"
+-- | The 'Face' type is an instance of 'ThreeDimensional' so that we
+-- can call the 'center' function on it. This is useful because the
+-- center of a face is always a vertex of a tetrahedron.
instance ThreeDimensional Face where
+ -- | Since a face is square, we can just average the four vertices
+ -- to find the center.
center f = ((v0 f) + (v1 f) + (v2 f) + (v3 f)) `scale` (1/4)
- -- Too lazy to implement this right now.
- contains_point _ _ = False
-
-
--- tetrahedron0 :: Face -> Tetrahedron
--- tetrahedron0 f =
--- Tetrahedron c v0' v1' v2' v3'
--- where
--- c = cube f
--- v0' = v0 f
--- v1' = v1 f
--- v2' = center f
--- v3' = center c
-
--- tetrahedron1 :: Face -> Tetrahedron
--- tetrahedron1 f =
--- Tetrahedron c v0' v1' v2' v3'
--- where
--- c = cube f
--- v0' = v1 f
--- v1' = v2 f
--- v2' = center f
--- v3' = center c
-
--- tetrahedron2 :: Face -> Tetrahedron
--- tetrahedron2 f =
--- Tetrahedron c v0' v1' v2' v3'
--- where
--- c = cube f
--- v0' = v2 f
--- v1' = v3 f
--- v2' = center f
--- v3' = center c
-
-
--- tetrahedron3 :: Face -> Tetrahedron
--- tetrahedron3 f =
--- Tetrahedron c v0' v1' v2' v3'
--- where
--- c = cube f
--- v0' = v3 f
--- v1' = v0 f
--- v2' = center f
--- v3' = center c
-
--- tetrahedrons :: Cube -> [Tetrahedron]
--- tetrahedrons c =
--- concat [
--- [tetrahedron0 f0, tetrahedron1 f0, tetrahedron2 f0, tetrahedron3 f0],
--- [tetrahedron0 f1, tetrahedron1 f1, tetrahedron2 f1, tetrahedron3 f2],
--- [tetrahedron0 f2, tetrahedron1 f2, tetrahedron2 f2, tetrahedron3 f2],
--- [tetrahedron0 f3, tetrahedron1 f3, tetrahedron2 f3, tetrahedron3 f3],
--- [tetrahedron0 f4, tetrahedron1 f4, tetrahedron2 f4, tetrahedron3 f4],
--- [tetrahedron0 f5, tetrahedron1 f5, tetrahedron2 f5, tetrahedron3 f5] ]
--- where
--- f0 = face0 c
--- f1 = face1 c
--- f2 = face2 c
--- f3 = face3 c
--- f4 = face4 c
--- f5 = face5 c
+ -- | It's possible to implement this, but it hasn't been done
+ -- yet. A face will contain a point if the point lies in the same
+ -- plane as the vertices of the face, and if it falls on the
+ -- correct side of the four sides of the face.
+ contains_point _ _ = False