Add trajectory to grenades, various refactoring

src/Dodge/Item/Weapon/UseEffect.hs

@@ -113,19 +113,19 @@ aTractorBeam
 aTractorBeam col cr w 
     = set (creatures . ix cid . crInv . ix itRef . itUse)
         (\_ -> aTractorBeam ((col + 1) `mod` 10))
-    $ over projectiles (IM.insert i (tractorBeamAt col i pos dir)) w
+    $ over props (IM.insert i (tractorBeamAt col i pos dir)) w
   where 
     i = newProjectileKey w
     cid = _crID cr
     pos = _crPos cr +.+ ((_crRad cr + 10) *.* unitVectorAtAngle dir)
     dir = _crDir cr
     itRef = _crInvSel cr
-tractorBeamAt :: Int -> Int -> Point2 -> Float -> Projectile
+tractorBeamAt :: Int -> Int -> Point2 -> Float -> Prop
 tractorBeamAt colID i pos dir = Projectile
     { _pjPos = pos
     , _pjStartPos = p'
     , _pjVel = d
-    , _pjDraw = const blank
+    , _prDraw = const (mempty,blank)
     , _pjID = i
     , _pjUpdate = \_ -> updateTractor colID 10 i
     }
@@ -137,12 +137,12 @@ tractorBeamAt colID i pos dir = Projectile
 The interaction of this with objects, walls etc needs more thought.  -}
 updateTractor :: Int -> Int -> Int -> World -> World
 updateTractor colID time i w
-    | time > 0 = set (projectiles . ix i . pjUpdate) (\_ -> updateTractor colID (time-1) i) 
-                    $ set (projectiles . ix i . pjDraw) (const pic)
+    | time > 0 = set (props . ix i . pjUpdate) (\_ -> updateTractor colID (time-1) i) 
+                    $ set (props . ix i . prDraw) (const (mempty,mempty))
                     $ over creatures (IM.map tractCr) 
                     $ over floorItems (IM.map tractFlIt) 
                         w
-    | otherwise = over projectiles (IM.delete i) w
+    | otherwise = over props (IM.delete i) w
   where 
     tractCr cr 
         | circOnSeg p1 p2 cP 10
@@ -166,7 +166,7 @@ updateTractor colID time i w
                 iP = _flItPos it
                 m | dist iP p1 < 350 = 1
                   | otherwise        = (410 - dist iP p1) / 60
-    pj = _projectiles w IM.! i
+    pj = _props w IM.! i
     q = _pjVel pj
     p1 = _pjPos pj
     p' = _pjStartPos pj