我正在测试在这里找到的简单乒乓球游戏:https ://github.com/shangaslammi/frp-pong
问题是键盘控制工作非常糟糕 - 按键非常无响应并且通常有几秒钟的延迟。我假设作者为 Windows 编写了代码,因为他包含了一个 .bat 文件,所以这是一个特定于 Linux 的问题。
为什么会这样?
我不确定问题出在哪里,但这里是文件 Keyboard.hs:
import Data.Set (Set)
import qualified Data.Set as Set
import Graphics.UI.GLUT (Key(..), KeyState(..))
-- | Set of all keys that are currently held down
newtype Keyboard = Keyboard (Set Key)
-- | Create a new Keyboard
initKeyboard :: Keyboard
initKeyboard = Keyboard Set.empty
-- | Record a key state change in the given Keyboard
handleKeyEvent :: Key -> KeyState -> Keyboard -> Keyboard
handleKeyEvent k Down = addKey k
handleKeyEvent k Up = removeKey k
addKey :: Key -> Keyboard -> Keyboard
addKey k (Keyboard s) = Keyboard $ Set.insert k s
removeKey :: Key -> Keyboard -> Keyboard
removeKey k (Keyboard s) = Keyboard $ Set.delete k s
-- | Test if a key is currently held down in the given Keyboard
isKeyDown :: Keyboard -> Key -> Bool
isKeyDown (Keyboard s) k = Set.member k s
并设置回调:
type KeyboardRef = IORef Keyboard
type TimeRef = IORef POSIXTime
type AccumRef = TimeRef
type PrevTimeRef = TimeRef
type GameRef = IORef (Rects, GameLogic)
type CallbackRefs = (AccumRef, PrevTimeRef, KeyboardRef, GameRef)
initCallbackRefs :: IO CallbackRefs
initCallbackRefs = do
accum <- newIORef secPerTick
prev <- getPOSIXTime >>= newIORef
keyb <- newIORef initKeyboard
cont <- newIORef ([],game)
return (accum, prev, keyb, cont)
-- | Update the Keyboard state according to the event
handleKeyboard :: CallbackRefs -> KeyboardMouseCallback
handleKeyboard (_, _, kb, _) k ks _ _ = modifyIORef kb (handleKeyEvent k ks)