Tweak picture layers

src/Dodge/Base/Zone.hs

@@ -110,13 +110,16 @@ zoneOfScreen w = [(a,b) | a <- [x - n .. x + n]
     wh = max (getWindowX w) (getWindowY w)
 
 zoneOfDoubleScreen :: World -> [(Int,Int)]
-zoneOfDoubleScreen w = [(a,b) | a <- [x - n .. x + n]
-                        , b <- [y - n .. y + n]
-                 ]
+zoneOfDoubleScreen w = (,) <$> xs <*> ys
+--    [(a,b) | a <- xs
+--           , b <- ys
+--    ]
   where 
     (x,y) = zoneOfPoint $ _cameraCenter w
     n = ceiling (wh / (_cameraZoom w * zoneSize)) * 2
     wh = max (getWindowX w) (getWindowY w)
+    xs = [x - n .. x + n]
+    ys = [y - n .. y + n]
 
 zoneOfSight :: World -> [(Int,Int)]
 zoneOfSight w = 
@@ -127,8 +130,24 @@ zoneOfSight w =
   where 
     (xs,ys) = unzip $ map zoneOfPoint $ screenPolygon w ++ [_cameraViewFrom w]
 
+wallsDoubleScreen :: World -> IM.IntMap Wall
+wallsDoubleScreen w -- = IM.unions [f b $ f a $ _wallsZone w | (a,b) <- is]
+    = foldl' (flip $ IM.union . \i -> innerFold (f i (_wallsZone w))) IM.empty xs
+  where 
+    innerFold m = foldl' (flip $ IM.union . \ j -> f j m) IM.empty ys
+
+    f i m = case IM.lookup i m of 
+        Just val -> val
+        _        -> IM.empty
+    (x,y) = zoneOfPoint $ _cameraCenter w
+    n = ceiling (wh / (_cameraZoom w * zoneSize)) * 2
+    wh = max (getWindowX w) (getWindowY w)
+    xs = [x - n .. x + n]
+    ys = [y - n .. y + n]
+
 wallsNearZones :: [(Int,Int)] -> World -> IM.IntMap Wall
-wallsNearZones is w = IM.unions [f b $ f a $ _wallsZone w | (a,b) <- is]
+wallsNearZones is w -- = IM.unions [f b $ f a $ _wallsZone w | (a,b) <- is]
+    = foldl' (flip $ IM.union . \(a,b) -> f b (f a (_wallsZone w))) IM.empty is
   where 
     f i m = case IM.lookup i m of 
         Just val -> val