Allow slimes to recombine

src/Dodge/Update.hs

@@ -1000,6 +1000,9 @@ crCrSpring c1 c2
     | vec == V2 0 0 = id
     | diff >= comRad = id
     | diffheight = id
+    | SlimeCrit{} <- c1 ^. crType
+    , SlimeCrit{} <- c2 ^. crType
+    , id2 > id1 = fuseSlimes c1 c2
     | otherwise = cWorld . lWorld . creatures %~ ( olap c1 c2 . olap' c2 c1)
   where
     z c = c ^. crPos . _z
@@ -1018,6 +1021,22 @@ crCrSpring c1 c2
     overlap c = ((comRad - diff) * crMass (_crType c) * 0.5 / massT) *^ signorm vec
     massT = crMass (_crType c1) + crMass (_crType c2)
 
+fuseSlimes :: Creature -> Creature -> World -> World
+fuseSlimes c1 c2 = (cWorld . lWorld . creatures . ix i1 .~ c)
+    . (cWorld . lWorld . creatures . at i2 .~ Nothing)
+  where
+    i1 = c1 ^. crID
+    i2 = c2 ^. crID
+    c = c1 & crType . slimeRad .~ r
+            & crType . slimeCompression .~ V2 r 0
+            & crPos . _xy .~ (r1/(r1+r2)) *^ xy1 + (r2/(r1+r2)) *^ xy2
+    xy1 = c1 ^. crPos . _xy
+    xy2 = c2 ^. crPos . _xy
+    r1 = c1 ^?! crType . slimeRad
+    r2 = c2 ^?! crType . slimeRad
+    r = sqrt (r1*r1 + r2*r2)
+    
+
 updateDelayedEvents :: World -> World
 updateDelayedEvents w =
     let (neww, newde) = mapAccumR f w (w ^. cWorld . lWorld . delayedEvents)