Commit before attempting to remove ptDraw field

src/Dodge/Item/Weapon/UseEffect.hs

@@ -52,10 +52,27 @@ drawPulse col pt = setLayer DebugLayer $ pictures sweepPics
     x = _ptTimer pt
 {- | Radar blip at a point.  -}
 blipAt :: Float -> Point2 -> Color -> Int -> Particle
-blipAt r p col i = Particle
-    {_ptDraw = const blank
-    ,_ptUpdate = mvBlip r p col i i
+blipAt r p col i = BlipParticle
+    {_ptDraw = drawBlip
+    ,_ptUpdate = \w pt -> if _ptTimer pt <= 0 then (w,Nothing) else (w,Just $ pt & ptTimer -~ 1)
+    ,_ptColor = col
+    ,_ptTimer = i
+    ,_ptMaxTime = i
+    ,_ptRad = r
+    ,_ptPos = p
     }
+drawBlip :: Particle -> Picture
+drawBlip pt = setDepth (-0.5)
+    . setLayer DebugLayer
+    . uncurryV translate p 
+    . color (withAlpha (fromIntegral t / fromIntegral maxt) col)
+    $ circleSolid r
+  where
+    p = _ptPos pt
+    t = _ptTimer pt
+    r = _ptRad pt
+    col = _ptColor pt
+    maxt = _ptMaxTime pt
 mvBlip :: Float
     -> Point2 -> Color 
     -> Int  -- ^ Max possible timer value