feat (Actions/Game): added random object placement

roadmap.md

@@ -1,12 +1,12 @@
 ## Features
 
-- Randomise obstacle placement
 - Jump animation should be controlled by fps
 
 ## Bugs
 
-- Collision detection fails at high speeds
 
 ## Done
 
 - Collision detection
+- Randomise obstacle placement
+- Collision detection fails at high speeds

src/Actions.hs

@@ -7,7 +7,7 @@ module Actions (
 import ClassyPrelude
 
 import Control.Lens ((&), (^.), (.~), (%~), (+~))
-import Types (Player, Direction(..), UI, Direction(..), State(..), Obstacles, reset, player, position, obstacles, state, speed)
+import Types (Player, Direction(..), UI, Direction(..), State(..), Obstacles, reset, player, position, obstacles, state, speed, dimensions)
 import Loop (fps)
 
 restart :: UI -> UI
@@ -20,26 +20,30 @@ jump ui = case ui ^. state of
     Playing -> ui & player %~ startJump
     _ -> ui
 
-frame :: UI -> UI
-frame ui = case ui ^. state of
-    Playing -> nextFrame ui
+frame :: Int -> UI -> UI
+frame rand ui = case ui ^. state of
+    Playing -> nextFrame rand ui
     _ -> ui
 
 -- internal functions
-nextFrame :: UI -> UI
-nextFrame ui = ui
+nextFrame :: Int -> UI -> UI
+nextFrame rand ui = ui
     & state .~ st
     & player %~ animate
     & position +~ distance
-    & obstacles %~ trimObstacles ui
+    & obstacles %~ generateObstacles rand ui
 
     where gameOver = collision ui
           distance = if gameOver then 0 else 1 / fromIntegral fps * fromIntegral (ui ^. speed)
           st = if gameOver then GameOver else Playing
 
-trimObstacles :: UI -> Obstacles -> Obstacles
-trimObstacles ui = filter (> pos)
+generateObstacles :: Int -> UI -> Obstacles -> Obstacles
+generateObstacles rand ui obs = if shouldAppend then filtered ++ [final + rand] else filtered
     where pos = floor $ ui ^. position
+          (w, _) = ui ^. dimensions
+          final = fromMaybe 0 $ lastMay obs
+          shouldAppend = pos + w > final
+          filtered = filter (> pos) obs
 
 collision :: UI -> Bool
 collision ui = next < pos + 2 && next > pos - 2 && jumpHeight < 2

src/Game.hs

@@ -2,7 +2,8 @@ module Game (play) where
 
 import ClassyPrelude
 
-import Control.Lens ((&), (.~))
+import Control.Lens ((&), (.~), (^.))
+import System.Random (getStdRandom, randomR)
 
 import Brick
 import Brick.BChan (newBChan)
@@ -12,13 +13,16 @@ import qualified Actions (restart, jump, frame)
 import Attr (attr)
 import Draw (draw)
 import Loop (loop)
-import Types (Name, UI, Tick(Tick), create, dimensions)
+import Types (Name, UI, Tick(Tick), create, speed, dimensions)
 import Window (getDimensions)
 
 handleTick :: UI -> EventM Name (Next UI)
 handleTick ui = do
+    let sp = ui ^. speed
+    let minDistance = sp `div` 2
     s <- liftIO getDimensions
-    continue $ Actions.frame (ui & dimensions .~ s)
+    r <- liftIO $ getStdRandom (randomR (minDistance, sp * 3))
+    continue $ Actions.frame r (ui & dimensions .~ s)
 
 handleEvent :: UI -> BrickEvent Name Tick -> EventM Name (Next UI)
 handleEvent ui (VtyEvent (EvKey (KChar 'q') [])) = halt ui
@@ -40,7 +44,7 @@ getSpeed :: IO Int
 getSpeed = do
     args <- getArgs
     return $ case args of
-        [speed] -> fromMaybe 10 $ readMay speed
+        [sp] -> fromMaybe 10 $ readMay sp
         _ -> 10
 
 
@@ -49,5 +53,5 @@ play = do
     chan <- newBChan 1
     loop chan
     s <- getDimensions
-    speed <- getSpeed
-    void $ customMain (mkVty defaultConfig) (Just chan) app $ create s speed
+    sp <- getSpeed
+    void $ customMain (mkVty defaultConfig) (Just chan) app $ create s sp

src/Types.hs

@@ -19,7 +19,7 @@ module Types (
 
 import ClassyPrelude
 
-import Control.Lens ((.~), makeLenses)
+import Control.Lens ((&), (^.), (.~), makeLenses)
 
 import Window (Dimensions)
 
@@ -44,16 +44,18 @@ create s sp = UI {
         _position = 0
       , _dimensions = s
       , _player = (Level, 0)
-      , _obstacles = [fst s, fst s + 18 .. 300]
+      , _obstacles = [fst s]
       , _state = Playing
       , _speed = sp
     }
 
 reset :: UI -> UI
-reset = (state .~ Playing)
-    . (player .~ (Level, 0))
-    . (obstacles .~ [20, 38 .. 300])
-    . (position .~ 0)
+reset ui = ui
+    & state .~ Playing
+    & player .~ (Level, 0)
+    & obstacles .~ [fst s]
+    & position .~ 0
+    where s = ui ^. dimensions
 
 data Tick = Tick
 type Name = ()