Tweak corpse/chasm interaction

src/Dodge/Creature/Update.hs

@@ -168,16 +168,30 @@ chasmTestCorpse cr w
         w
             & tocr . crZVel -~ 0.5
             & tocr . crPos . _z +~ _crZVel cr
-    | Just (x, y) <- List.find g (w ^. cWorld . cliffs) =
+    -- only look for TWO cliffs to push along
+    | (xy:xys) <- filter g (w ^. cWorld . cliffs) =
         w
             & soundContinue (CrChasm (_crID cr)) (cr ^. crPos . _xy) debrisS (Just 100)
-            & tocr . crPos . _xy +~ normalizeV (vNormal (x - y))
+            & tocr . crPos . _xy +~ h xy xys
     | any f (w ^. cWorld . chasms) = w & tocr . crZVel -~ 0.5
     | otherwise = w
   where
+    
+    h :: (Point2,Point2) -> [(Point2,Point2)] -> Point2
+    h (x,y) [] = normalizeV (vNormal (x-y))
+    h x (y:_) = unitVectorAtAngle $ tweenAngles (d1/(d1+d2)) (h' x) (h' y)
+      where
+        h' :: (Point2,Point2) -> Float
+        h' = argV . vNormal . uncurry (-)
+        d a = uncurry closestPointOnLine a (cr ^. crPos . _xy)
+        d1 :: Float
+        d1 = norm (cxy - d x)
+        d2 :: Float
+        d2 = norm (cxy - d y)
+    cxy = cr ^. crPos . _xy
     tocr = cWorld . lWorld . creatures . ix (_crID cr)
-    g = uncurry $ circOnSeg (cr ^. crPos . _xy) (crRad $ cr ^. crType)
-    f = pointInPoly (cr ^. crPos . _xy)
+    g = uncurry $ circOnSeg cxy (crRad $ cr ^. crType)
+    f = pointInPoly cxy
 
 chasmRotate :: Creature -> Point2 -> World -> World
 chasmRotate cr v w