src/Controller.hs

@@ -232,11 +232,14 @@ spawnPowerup gen Nothing = (Just genPowerup, newGen)
     (index, newGen) = randomR (fromEnum (minBound :: Effect), fromEnum (maxBound :: Effect)) gen''
     genPowerup = Powerup (genX, genY) (toEnum index)
 
+powerupRadius :: Float
+powerupRadius = 15
+
 checkPowerupCollision :: GameState -> GameState
 checkPowerupCollision gstate@(GameState {spaceShip, powerup}) =
   case powerup of
     Nothing -> gstate
-    Just x -> if (collidesWith 15 (position x) (location spaceShip)) 
+    Just x -> if (collidesWith powerupRadius (position x) (location spaceShip)) 
             then (claimPowerup gstate) 
             else gstate
 

src/Model.hs

@@ -8,6 +8,19 @@ import System.Random
 
 import System.IO (withFile, IOMode(ReadMode), hGetContents)
 
+class Spawnable a where
+  getLastSpawn :: a -> Float
+  spawn :: StdGen -> (a, StdGen)
+
+class Moving a where
+  getLocation :: a -> Location
+  getOrientation :: a -> Orientation
+  getVelocity :: a -> Velocity
+  move :: Float -> a -> a
+  --checkCollision :: a -> GameState -> Bool (!) not sure if we need this
+
+data MovingObject = MovingObject Location Orientation Velocity
+
 type Velocity = Float
 type Location = (Float, Float)
 type Orientation = Float
@@ -31,7 +44,16 @@ data Specifications = Specs {
 
 type Size = Int
 data Meteor = Meteor { coordinates :: Location, directoin :: Orientation, pace :: Velocity, size :: Size}
-data UFO = UFO Location Orientation Velocity Bullet
+data UFO = UFO MovingObject Bullet
+
+instance Moving UFO where
+  getLocation (UFO (MovingObject x _ _) _) = x
+  getOrientation (UFO (MovingObject _ x _) _) = x
+  getVelocity (UFO (MovingObject _ _ x) _) = x
+  move secs (UFO (MovingObject loc orient v) b) = UFO (MovingObject loc orient v) b
+
+
+
 type Score = Int
 type Name = String
 type Highscore = (Name, Score)
@@ -61,8 +83,10 @@ data GameState = GameState {
                  , elapsedTime :: Float
                  , powerupTimer :: Float
                  , meteorTimer :: Float
+                 , ufoTimer :: Float
                  , spaceShip :: Spaceship
                  , meteors :: [Meteor]
+                 , ufos :: [UFO]
                  , powerup :: Maybe Powerup
                  , seed :: StdGen -- Each game has its own 'seed' which allows for pure randomness
                  }
@@ -113,9 +137,11 @@ initialState seed = GameState {
   , player = Player 3 0 "Player"
   , elapsedTime = 0
   , powerupTimer = 0
+  , ufoTimer = 0
   , spaceShip = Spaceship (0,0) 0 0 [] seed 0 defaultSpecs
   , powerup = Nothing
   , meteors = []
+  , ufos = []
   , notification = ""
   , tooltip = ""
   , seed = seed