First (buggy) implementation of rewind gun

src/Dodge/Creature.hs

@@ -163,7 +163,7 @@ startCr = defaultCreature
 {- | Items you start with.  -}
 startInvList :: [Item]
 startInvList =
-    [
+    [ rewindGun
     ]
 startInventory :: IM.IntMap Item
 startInventory = IM.fromList $ zip [0..defaultInvSize -1] $ startInvList ++ repeat NoItem

src/Dodge/Creature/Perception.hs

@@ -59,8 +59,8 @@ isCognizant _ = False
 
 combineAwareness :: AwarenessLevel -> AwarenessLevel -> AwarenessLevel
 combineAwareness (Suspicious x) (Suspicious y) 
-    | x + y < 10000 = Suspicious $ x + y
-    | otherwise   = Cognizant 5000
+    | x + y < 5000 = Suspicious $ x + y
+    | otherwise   = Cognizant 1000
 combineAwareness (Suspicious x) (Cognizant y) = Cognizant $ min 10000 $ x + y
 combineAwareness (Cognizant x) (Suspicious y) = Cognizant $ min 10000 $ x + y
 combineAwareness (Cognizant x) (Cognizant y)    = Cognizant $ min 10000 $ x + y
@@ -70,7 +70,7 @@ combineAwareness (Cognizant x) (Cognizant y)    = Cognizant $ min 10000 $ x + y
 decreaseAwareness :: AwarenessLevel -> Maybe AwarenessLevel
 decreaseAwareness (Suspicious 0) = Nothing
 decreaseAwareness (Suspicious x) = Just $ Suspicious (x - 50)
-decreaseAwareness (Cognizant 0) = Just $ Suspicious 10000
+decreaseAwareness (Cognizant 0) = Just $ Suspicious 1000
 decreaseAwareness (Cognizant x) = Just $ Cognizant $ x - 50
 
 {- | Given a fixed group of creatures, direct attention to those of them that

src/Dodge/Data.hs

@@ -115,6 +115,7 @@ data World = World
     , _config               :: Configuration
     , _preloadData          :: PreloadData
     , _savedWorlds          :: M.Map SaveSlot World
+    , _rewindWorlds         :: [World]
     , _frameClock           :: Int
     }
 
@@ -421,12 +422,17 @@ data ItemDimension = ItemDimension
 
 data ReloadType = ActiveReload | PassiveReload SoundID
 
+-- I believe this is called every frame, not sure when though
 data ItEffect = NoItEffect
     | ItInvEffect 
         {_itInvEffect       :: ItEffect -> Creature -> Int -> World -> World
                 -- the Int is the items inventory position
         ,_itEffectCounter   :: Int
         }
+    | ItRewindEffect
+        {_itInvEffect       :: ItEffect -> Creature -> Int -> World -> World
+        ,_itStoredWorlds    :: [World]
+        }
     | ItEffect 
         {_itInvEffect       :: ItEffect -> Creature -> Int -> World -> World 
         ,_itFloorEffect     :: Int -> World -> World 

src/Dodge/Default/World.hs

@@ -84,6 +84,7 @@ defaultWorld = World
     , _preloadData = DummyPdata -- hack TODO remove this
     , _frameClock = 0
     , _worldBounds = defaultBounds
+    , _rewindWorlds = []
     }
 youLight :: TempLightSource
 youLight = 

src/Dodge/Item/Data.hs

@@ -27,6 +27,7 @@ data ItemIdentity
     | LongGun
     | Flamethrower
     | Blinker
+    | Rewinder
     | Grenade
     | RemoteBomb
     | TeslaGun

src/Dodge/Item/Weapon/Utility.hs

@@ -1,5 +1,6 @@
 module Dodge.Item.Weapon.Utility where
 import Dodge.Data
+import Dodge.Base
 import Dodge.Default
 import Dodge.Picture.Layer
 import Dodge.Creature.Action
@@ -7,11 +8,35 @@ import Dodge.Item.Weapon.TriggerType
 import Dodge.Default.Weapon
 import Geometry
 import Picture
---import qualified IntMapHelp as IM
+import qualified IntMapHelp as IM
 import Shape
 import ShapePicture
 
 import Control.Lens
+
+rewindGun :: Item
+rewindGun = defaultGun
+    { _itName = "REWINDER"
+    , _itIdentity = Rewinder
+    , _wpMaxAmmo  = 0
+    , _wpLoadedAmmo = 0
+    , _itUse = useRewindGun 
+    , _itEffect = ItRewindEffect rewindEffect []
+    , _itLeftClickUse = Just $ \cr invid -> useRewindGun (_crInv cr IM.! invid) cr
+    }
+rewindEffect :: ItEffect -> Creature -> Int -> World -> World
+rewindEffect iteff cr invid w = w & rewindWorlds %~ (take 100 . (w' : ))
+    & creatures . ix (_crID cr) . crInv . ix invid . wpLoadedAmmo .~ length (_rewindWorlds w)
+  where
+    w' = w & rewindWorlds .~ []
+
+useRewindGun :: Item -> Creature -> World -> World
+useRewindGun it cr w = case _rewindWorlds w of
+    (_:w':ws) -> w' & keys .~ _keys w
+        & mouseButtons .~ _mouseButtons w
+        & rewindWorlds .~ ws
+    _ -> w
+
 shrinkGun :: Item
 shrinkGun = defaultGun
     { _itName = "SHRINKER"