Implement multiple radial distortion rendering

src/Dodge/Update.hs

@@ -53,6 +53,7 @@ update' w = case _menuLayers w of
         w
     (_ : _) -> w
     []  -> checkEndGame 
+        . updateRadialDistortions
         . updateTriggers
         . ppEvents 
         . updateCamera
@@ -89,6 +90,17 @@ updateCreatureGroups :: World -> World
 updateCreatureGroups w = w & creatureGroups %~ 
     IM.mapMaybe (\cgp -> _crGroupUpdate cgp w cgp)
 
+updateRadialDistortions :: World -> World
+updateRadialDistortions = radDistortion %~ mapMaybe decreaseBulge
+
+decreaseBulge 
+    :: (Point2,Point2,Point2,Float) 
+    -> Maybe (Point2,Point2,Point2,Float)
+decreaseBulge (a,b,c,v)
+    | v > 1 = Just (a,b,c,max 1 (v - 0.05) )
+    | v < 1 = Just (a,b,c,min 1 (v + 0.05) )
+    | otherwise = Nothing
+
 updateTriggers :: World -> World
 updateTriggers w 
     | ResetLevel 1 `S.member` _worldTriggers w = generateLevelFromRoomList levx $ initialWorld