Remove force fields, cleanup

src/Dodge/Particle/Bullet/Update.hs

@@ -1,8 +1,7 @@
-{-
-Bullet update.
- -}
+{- Bullet update.  -}
 module Dodge.Particle.Bullet.Update
-    where
+    ( mvGenBullet
+    ) where
 import Dodge.Data
 --import Dodge.Base
 import Dodge.WorldEvent.ThingsHit
@@ -10,20 +9,16 @@ import Dodge.WorldEvent.ThingsHit
 import Geometry
 
 import Control.Lens
---import Data.Maybe
---import Data.List
---import Data.Bifunctor
---import qualified Data.IntMap.Strict as IM
-
 {-
 Update for a generic bullet.
 -}
 mvGenBullet :: World -> Particle -> (World, Maybe Particle)
 mvGenBullet w bt 
     | t <= 0 = (w, Nothing)
-    | t < 4  = (w, Just $ set btPassThrough' Nothing
-                        $ set btTrail' (p:p:ps)
-                        $ set btTimer' (t-1) bt                      
+    | t <  4 = (w, Just $ bt
+                    & btPassThrough' .~ Nothing
+                    & btTrail' .~ (p:p:ps)
+                    & btTimer' -~ 1                      
                )
     | otherwise = hiteff bt (thingsHitExceptCr mcr p (p +.+ vel) w) w
   where