Move toward diagnosing state update leak

src/Dodge/Creature/State.hs

@@ -32,24 +32,19 @@ import System.Random
 --import qualified Data.Map as M
 import Data.Monoid
 
-type CRUpdate = World -> (World -> World,StdGen) -> Creature -> ((World -> World,StdGen), Maybe Creature)
+dummyUpdate :: CRUpdate
+dummyUpdate cr _ = (Endo id, Just cr)
 
-
-meleeCooldown :: CRUpdate -> CRUpdate
-meleeCooldown u w (f,g) cr = u w (f,g) $ cr & crMeleeCooldown . _Just %~ (max 0 . (\x -> x - 1))
 -- | The movement is updated before the ai in order to correctly set the oldpos.
--- the whole of this update cycle could do with a rethink, it is becoming
--- convoluted
 stateUpdate :: CRUpdate -> CRUpdate
-stateUpdate u w (f,g) cr = case u w (f,g) (updateMovement g cr) of
-        ((f',g') , maybeCr) -> 
-            (   (invSideEff cr . movementSideEff cr . deathEff . f'
-                , g')
-            , fmap (stepReloading . stepItemUseCooldown . doDamage . crAutoReload) $ crOrCorpse =<< maybeCr
-            )
+stateUpdate u cr w = case u (updateMovement cr) w of
+    (f, maybeCr) -> 
+        ( Endo $ invSideEff cr . movementSideEff cr . deathEff . appEndo f
+        , fmap (stepReloading . stepItemUseCooldown . doDamage . crAutoReload) $ crOrCorpse =<< maybeCr
+        )
   where   
-    crOrCorpse cr''' 
-        | cr''' ^. crHP > 0 = Just cr'''
+    crOrCorpse cr' 
+        | cr' ^. crHP > 0 = Just cr'
         | otherwise      = Nothing
     deathEff 
         | cr ^.crHP > 0 = id
@@ -80,6 +75,9 @@ velocity to carry across frames.
 crFriction :: Creature -> Point2 -> Point2
 crFriction _ _ = V2 0 0
 
+meleeCooldown :: CRUpdate -> CRUpdate
+meleeCooldown u cr = u $ cr & crMeleeCooldown . _Just %~ (max 0 . (\x -> x - 1))
+
 doDamage :: Creature -> Creature
 doDamage cr = set (crState . crDamage) [] 
     $ over (crState . crPastDamage) (forceFoldable . take 10 . (dams :) ) damagedCr
@@ -135,16 +133,15 @@ weaponReloadSounds cr w = case _crInv cr IM.!? _crInvSel cr of
   where 
     cid = _crID cr
 
-updateMovement :: StdGen -> Creature -> Creature
-updateMovement g cr 
+updateMovement :: Creature -> Creature
+updateMovement cr 
     | isFrictionless cr = over crPos (+.+ momentum) $ setOldPos cr
     | otherwise = updateWalkCycle $ setOldPos cr
   where
     momentum' = 0.98 *.* (_crPos cr -.- _crOldPos cr)
     momentum'' | magV momentum' > 1 = 1 *.* normalizeV momentum'
                | otherwise          = momentum'
-    momentum = momentum'' +.+ 0.01 *.* unitVectorAtAngle randAng
-    (randAng,_) = randomR (0,2*pi) g
+    momentum = momentum''
 
 isFrictionless :: Creature -> Bool
 isFrictionless cr = case cr ^? crStance . carriage of
@@ -169,29 +166,30 @@ decreaseToZero :: Int -> Int
 decreaseToZero x = max 0 (x - 1) 
 
 onDeath :: (Creature -> World -> World) -> CRUpdate -> CRUpdate
-onDeath h u w (f,g) cr 
-    | _crHP cr > 0 = u w (f,g) cr
-    | otherwise    = ( ( h cr . f, g ) , Nothing )
+onDeath h u cr w
+    | _crHP cr > 0 = u cr w
+    | otherwise    = ( Endo $ h cr , Nothing )
 
 updateBarrel 
-    :: World 
-    -> (World -> World,StdGen) 
-    -> Creature 
-    -> ((World -> World , StdGen), Maybe Creature)
-updateBarrel _ (f,g) cr 
-    | _crHP cr > 0 = ((f, g), newCr)
-    | otherwise   = ((f, g), Nothing)
+    :: Creature 
+    -> World
+    -> (Endo World, Maybe Creature)
+updateBarrel cr _
+    | _crHP cr > 0 = (Endo id, newCr)
+    | otherwise    = (Endo id, Nothing)
   where 
     newCr = Just $ doDamage cr
 
--- it is easy to leave off the "f" here 
--- should find some better way of doing all this that is less prone to error
-updateExpBarrel :: 
-    World -> (World -> World,StdGen) -> Creature -> ((World -> World , StdGen), Maybe Creature)
-updateExpBarrel _ (f,g) cr 
-    | _crHP cr > 0 = ((f . foldr (.) id pierceSparks . hiss, g'), newCr)
-    | otherwise   = ((f . makeExplosionAt (_crPos cr) . stopSounds , g'), Nothing)
+-- should generate the sparks externally using new random generators
+updateExpBarrel 
+    :: Creature 
+    -> World
+    -> (Endo World, Maybe Creature)
+updateExpBarrel cr w 
+    | _crHP cr > 0 = (Endo $ foldr (.) id pierceSparks . hiss, newCr)
+    | otherwise    = (Endo $ makeExplosionAt (_crPos cr) . stopSounds , Nothing)
   where 
+    g = _randGen w
     damages = _crDamage $ _crState cr
     pierceSparks :: [World -> World]
     pierceSparks 
@@ -200,7 +198,6 @@ updateExpBarrel _ (f,g) cr
     as =  randomRs (-0.7,0.7) g
     colids = randomRs (0,11) g
     times = randomRs (2,5) g
-    (g',_) = split g
     poss = _piercedPoints $ _crSpState $ _crState cr
     --newCr = Just $ doDamage $ applyFuseDamage cr -- $ foldr perforate cr damages
     newCr = Just $ applyFuseDamage $ set (crState . crDamage) [] $ damToExpBarrel damages cr