Improve forcefield visuals

src/Dodge/Data.hs

@@ -1042,8 +1042,8 @@ data Wall = Wall
 data Opacity
     = SeeThrough
     | SeeAbove
+    | DrawnWall {_opDraw :: Wall -> SPic}
     | Opaque
-  deriving (Eq,Ord,Show)
 data WallStructure 
     = StandaloneWall
     | DoorPart    { _wlStDoor    :: Int }
@@ -1585,6 +1585,7 @@ makeLenses ''Modification
 makeLenses ''Particle
 makeLenses ''Wall
 makeLenses ''WallStructure
+makeLenses ''Opacity
 makeLenses ''PressPlate
 makeLenses ''Button
 makeLenses ''ActionPlan