Restructuring, #9

lib/RPGEngine/Data/Game.hs

@@ -0,0 +1,22 @@
+module RPGEngine.Data.Game
+( isLegalMove
+) where
+
+import RPGEngine.Data
+    ( Player(Player, position),
+      Direction,
+      Physical(Exit, Walkable, Entrance),
+      State(Playing, level),
+      Game(Game, state, player) )
+import RPGEngine.Data.Level (findAt, directionOffsets)
+
+------------------------------ Exported ------------------------------
+
+-- Check if a move is legal by checking what is located at the new position.
+isLegalMove :: Direction -> Game -> Bool
+isLegalMove dir g@Game{ state = Playing { level = lvl }, player = p@Player{ position = (x, y) }} = legality
+    where legality = physical `elem` [Walkable, Entrance, Exit]
+          physical = findAt newPos lvl
+          newPos   = (x + xD, y + yD)
+          (xD, yD) = directionOffsets dir
+isLegalMove _   _ = False