Make thingsHit use streaming

src/Dodge/WorldEvent/ThingsHit.hs

@@ -6,9 +6,7 @@ module Dodge.WorldEvent.ThingsHit
     ( thingsHit
     , wallsHit
     , thingHit
-    , thingsHitLongLine
     , thingsHitExceptCr
-    , thingsHitExceptCrLongLine
     )
     where
 import Dodge.Data
@@ -20,27 +18,31 @@ import qualified Data.IntMap.Strict as IM
 import Data.List
 import Data.Maybe
 import Data.Bifunctor
+import Streaming
+import qualified Streaming.Prelude as S
+
 {- List those objects that appear on a line.  -}
 thingsHit
     :: Point2    -- ^ Line start point
     -> Point2    -- ^ Line end point
     -> World 
-    -> [(Point2, Either Creature Wall)]
+    -> Stream (Of (Point2, Either Creature Wall)) Identity ()
 thingsHit sp ep w 
-    | sp == ep  = []
-    | otherwise = sortOn (dist sp . fst) (crs ++ wls)
+    | sp == ep  = S.each []
+    | otherwise = fmap (const ()) $ S.mergeOn (dist sp . fst) crs wls
   where 
-    crs = mapMaybe 
-        (\cr -> (,Left cr) <$> listToMaybe (intersectCircSeg (_crPos cr) (_crRad cr) sp ep))
-        . IM.elems 
+    crs :: Stream (Of (Point2, Either Creature Wall)) Identity ()
+    crs = sortStreamOn (dist sp . fst)
+        . S.mapMaybe 
+            (\cr -> (,Left cr) <$> listToMaybe (intersectCircSeg (_crPos cr) (_crRad cr) sp ep))
+        . S.each 
         $ _creatures w
-    wls = map (second Right) . IM.elems $ wallsOnLineHit sp ep 
-        $ IM.unions [f b $ f a $ _znObjects $ _wallsZone w 
-            | a<-[x-1,x,x+1] , b<-[y-1,y,y+1]]
-    (x,y) = zoneOfPoint (0.5 *.* (sp +.+ ep))
-    f i = fromMaybe IM.empty . IM.lookup i
+    wls :: Stream (Of (Point2, Either Creature Wall)) Identity ()
+    wls = S.map (second Right) 
+        . sortStreamOn (dist sp . fst)
+        . overlapSegWalls sp ep $ wallsAlongLine sp ep w
 thingHit :: Point2 -> Point2 -> World -> Maybe (Point2, Either Creature Wall)
-thingHit sp ep = listToMaybe . thingsHit sp ep
+thingHit sp ep = runIdentity . S.head_ . thingsHit sp ep
 {- List objects that appear on a line.
 Can filter out a creature.  -}
 thingsHitExceptCr 
@@ -48,9 +50,9 @@ thingsHitExceptCr
     -> Point2    -- ^ Line start point
     -> Point2    -- ^ Line end point
     -> World 
-    -> [(Point2, Either Creature Wall)]
+    -> Stream (Of (Point2, Either Creature Wall)) Identity ()
 thingsHitExceptCr Nothing    sp ep = thingsHit sp ep
-thingsHitExceptCr (Just cid) sp ep = filter crNotCid . thingsHit sp ep
+thingsHitExceptCr (Just cid) sp ep = S.filter crNotCid . thingsHit sp ep
   where 
     crNotCid (_,Left cr) = _crID cr /= cid
     crNotCid _ = True
@@ -70,27 +72,3 @@ wallsHit sp ep w
        -- $ _walls w
     (x,y) = zoneOfPoint (0.5 *.* (sp +.+ ep))
     f i = fromMaybe IM.empty . IM.lookup i
-
-thingsHitExceptCrLongLine 
-    :: Maybe Int 
-    -> Point2 
-    -> Point2 
-    -> World 
-    -> [(Point2, Either Creature Wall)]
-thingsHitExceptCrLongLine Nothing    sp ep = thingsHitLongLine sp ep
-thingsHitExceptCrLongLine (Just cid) sp ep = filter crNotCid . thingsHitLongLine sp ep
-  where 
-    crNotCid (_,Left cr) = _crID cr /= cid
-    crNotCid _ = True
-
-thingsHitLongLine :: Point2 -> Point2 -> World -> [(Point2, Either Creature Wall)]
-thingsHitLongLine sp ep w 
-    | sp == ep  = []
-    | otherwise = sortOn (dist sp . fst) (crs ++ wls)
-  where
-    crs = mapMaybe 
-        (\cr -> (,Left cr) <$> listToMaybe (intersectCircSeg (_crPos cr) (_crRad cr) sp ep))
-        . IM.elems 
-        $ _creatures w
-    --   $ creaturesAlongLine sp ep w
-    wls = map (second Right) . IM.elems $ wallsOnLineHit sp ep $ _walls w