make sure playedr only checks collisions with enemy in the case that player was previously attacked

fcore/player.sml

@@ -406,19 +406,24 @@ struct
         (player, walls, wallTree, platforms, platformTree)
       val player = PlayerPatch.withPatches (player, patches)
 
-      (* player reaction to collisions with enemies *)
+    in
-      val patches =
+      (* player reaction to collisions with enemies.
+       * We only detect collisions if player is not in invincibility period
+       * after being previously attacked. *)
+      case #attacked player of
+        ATTACKED _ => player
+      | _ =>
           let
             val {x, y, ...} = player
             val size = Constants.playerSize
             val env = (#enemies game, player)
             val state = []
-        in
+            val patches = FoldEnemies.foldRegion
-          FoldEnemies.foldRegion (x, y, size, size, env, state, enemyTree)
+              (x, y, size, size, env, state, enemyTree)
-        end
           in
             PlayerPatch.withPatches (player, patches)
           end
+    end
 
   (* todo: add attacked enemies to player's 'enemies' field *)
   fun concatAttackedEnemies (player: player, enemyCollisions) =