Refactor material sounds

src/Dodge/Data/Wall.hs

@@ -3,6 +3,7 @@
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE DeriveGeneric #-}
 module Dodge.Data.Wall where
+import Dodge.Data.Material
 import Geometry
 import Color
 import ShapePicture
@@ -39,8 +40,6 @@ data WallStructure
         { _wlStCreature :: Int 
 --        , _wlStDamCreature :: Damage -> Wall -> Int -> World -> World
         }
-data Material = Wood | Dirt | Stone | Glass | Metal | Crystal
-  deriving (Eq,Ord,Show,Bounded,Enum)
 makeLenses ''Wall
 makeLenses ''WallStructure
 makeLenses ''Opacity