Reify block drawing

src/Dodge/Magnet/Update.hs

@@ -0,0 +1,10 @@
+module Dodge.Magnet.Update
+    where
+import Dodge.Data.Magnet
+import Control.Lens
+
+doMagnetUpdate :: MagnetUpdate -> Magnet -> Maybe Magnet
+doMagnetUpdate mu = case mu of
+    MagnetUpdateTimer i 
+        | i < 1     -> const Nothing
+        | otherwise -> Just . (mgUpdate .~ MagnetUpdateTimer (i - 1))