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| module Breakout (component) where
import Prelude
import CSS (background, block, display, margin, marginBottom, marginLeft, marginRight, marginTop, padding, px, rgb)
import CSS.Common (auto)
import Control.Monad.Rec.Class (forever)
import Data.Maybe (Maybe(..))
import Data.Time.Duration (Milliseconds(..))
import Effect (Effect)
import Effect.Aff as Aff
import Effect.Aff.Class (class MonadAff)
import Graphics.Canvas (CanvasElement, Dimensions)
import Graphics.Canvas as Canvas
import Halogen (SubscriptionId)
import Halogen as H
import Halogen.HTML as HH
import Halogen.HTML.CSS (style)
import Halogen.HTML.Properties as HP
import Halogen.Query.Event (eventListener)
import Halogen.Subscription as HS
import Math as Math
import Web.Event.Event as E
import Web.HTML (window)
import Web.HTML.HTMLDocument as HTMLDocument
import Web.HTML.Window as Window
import Web.UIEvent.KeyboardEvent as KE
import Web.UIEvent.KeyboardEvent.EventTypes as KET
import Web.HTML.Location as Location
canvasId :: String
canvasId = "myCanvas"
paddleHeight = 10.0 :: Number
paddleWidth = 75.0 :: Number
ballRadius = 10.0 :: Number
type Dataset
= { x :: Number
, y :: Number
, dx :: Number
, dy :: Number
, paddleX :: Number
, leftPressed :: Boolean
, rightPressed :: Boolean
}
type State
= { maybeCanvas :: Maybe CanvasElement
, maybeTimer :: Maybe SubscriptionId
, dataset :: Dataset
}
data Action
= Initialize
| Tick
| HandleKeyDown KE.KeyboardEvent
| HandleKeyUp KE.KeyboardEvent
component :: forall query input output m. MonadAff m => H.Component query input output m
component =
H.mkComponent
{ initialState
, render
, eval:
H.mkEval
$ H.defaultEval
{ handleAction = handleAction
, initialize = Just Initialize
}
}
initialState :: forall i. i -> State
initialState _ =
{ maybeCanvas: Nothing
, maybeTimer: Nothing
, dataset:
{ x: 0.0
, y: 0.0
, dx: 0.0
, dy: 0.0
, paddleX: 0.0
, leftPressed: false
, rightPressed: false
}
}
render :: forall m. State -> H.ComponentHTML Action () m
render state =
HH.main
[ style do
margin (px 0.0) (px 0.0) (px 0.0) (px 0.0)
padding (px 0.0) (px 0.0) (px 0.0) (px 0.0)
]
[ HH.canvas
[ style do
background (rgb 238 238 238)
display block
marginTop (px 0.0)
marginRight auto
marginBottom (px 0.0)
marginLeft auto
, HP.id canvasId
, HP.width 480
, HP.height 320
]
, HH.text $ show state.dataset
]
handleAction :: forall output m. MonadAff m => Action -> H.HalogenM State Action () output m Unit
handleAction = case _ of
Initialize -> do
-- keyboard event
document <- H.liftEffect $ Window.document =<< window
H.subscribe' \_ ->
eventListener
KET.keydown
(HTMLDocument.toEventTarget document)
(map HandleKeyDown <<< KE.fromEvent)
H.subscribe' \_ ->
eventListener
KET.keyup
(HTMLDocument.toEventTarget document)
(map HandleKeyUp <<< KE.fromEvent)
-- timer
sid <- H.subscribe =<< timer Tick
--
init <- H.liftEffect initialize
H.put init { maybeTimer = Just sid }
Tick -> do
(state :: State) <- H.get
case { a: state.maybeCanvas, b: state.maybeTimer } of
{ a: Just canvas, b: Just timerSubscriptionId } -> do
ret <- H.liftEffect $ draw canvas state.dataset
if ret.gameover then do
H.liftEffect $ Window.alert "GAME OVER" =<< window
H.liftEffect $ Location.reload =<< Window.location =<< window
H.unsubscribe timerSubscriptionId
else
H.modify_ \st -> st { dataset = ret.nextDataset }
_ -> pure unit
HandleKeyDown ev
| KE.key ev == "Right" || KE.key ev == "ArrowRight" -> do
H.liftEffect $ E.preventDefault (KE.toEvent ev)
H.modify_ \st -> st { dataset { rightPressed = true } }
| KE.key ev == "Left" || KE.key ev == "ArrowLeft" -> do
H.liftEffect $ E.preventDefault (KE.toEvent ev)
H.modify_ \st -> st { dataset { leftPressed = true } }
| otherwise -> pure unit
HandleKeyUp ev
| KE.key ev == "Right" || KE.key ev == "ArrowRight" -> do
H.liftEffect $ E.preventDefault (KE.toEvent ev)
H.modify_ \st -> st { dataset { rightPressed = false } }
| KE.key ev == "Left" || KE.key ev == "ArrowLeft" -> do
H.liftEffect $ E.preventDefault (KE.toEvent ev)
H.modify_ \st -> st { dataset { leftPressed = false } }
| otherwise -> pure unit
where
initialize :: Effect State
initialize =
Canvas.getCanvasElementById canvasId
>>= case _ of
Nothing -> pure $ initialState unit
Just canvas -> do
dim <- Canvas.getCanvasDimensions canvas
pure
{ maybeCanvas: Just canvas
, maybeTimer: Nothing
, dataset:
{ x: dim.width / 2.0
, y: dim.height - 30.0
, dx: 2.0
, dy: (-2.0)
, paddleX: (dim.width - paddleWidth) / 2.0
, leftPressed: false
, rightPressed: false
}
}
draw :: CanvasElement -> Dataset -> Effect { nextDataset :: Dataset, gameover :: Boolean }
draw canvas dataset = do
dim <- H.liftEffect $ Canvas.getCanvasDimensions canvas
ctx <- Canvas.getContext2D canvas
--
Canvas.clearRect ctx { x: 0.0, y: 0.0, width: dim.width, height: dim.height }
drawBall
drawPaddle dim
pure $ nextDataset dim
where
drawBall :: Effect Unit
drawBall = do
ctx <- Canvas.getContext2D canvas
--
Canvas.beginPath ctx
Canvas.arc ctx
{ x: dataset.x
, y: dataset.y
, radius: ballRadius
, start: 0.0
, end: Math.pi * 2.0
}
Canvas.setFillStyle ctx "#0095DD"
Canvas.fill ctx
Canvas.closePath ctx
drawPaddle :: Dimensions -> Effect Unit
drawPaddle { height: height } = do
ctx <- Canvas.getContext2D canvas
--
Canvas.beginPath ctx
Canvas.rect ctx
{ x: dataset.paddleX
, y: height - paddleHeight
, width: paddleWidth
, height: paddleHeight
}
Canvas.setFillStyle ctx "#0095DD"
Canvas.fill ctx
Canvas.closePath ctx
nextDataset :: Dimensions -> { nextDataset :: Dataset, gameover :: Boolean }
nextDataset c =
let
{ x: x, y: y, dx: dx, dy: dy } = dataset
r = ballRadius
newPaddleX = case { left: dataset.leftPressed, right: dataset.rightPressed } of
{ left: false, right: true } -> dataset.paddleX + 7.0
{ left: true, right: false } -> dataset.paddleX - 7.0
_ -> dataset.paddleX
{ nextDy: nextDy, gameover: gameover } =
let
touchTheCeiling = (y + dy) < r
touchTheFloor = (y + dy) > (c.height - r)
touchThePaddle = touchTheFloor && between dataset.paddleX (dataset.paddleX + paddleWidth) (x + dx)
in
case true of
_
| touchTheCeiling -> { nextDy: (-dy), gameover: false }
| touchThePaddle -> { nextDy: (-dy), gameover: false }
| touchTheFloor -> { nextDy: (-dy), gameover: true }
| otherwise -> { nextDy: dy, gameover: false }
in
{ nextDataset:
dataset
{ x = x + dx
, y = y + dy
, dx =
if between r (c.width - r) (x + dx) then
dx
else
(-dx)
, dy = nextDy
, paddleX = clamp 0.0 (c.width - paddleWidth) newPaddleX
}
, gameover: gameover
}
timer :: forall m a. MonadAff m => a -> m (HS.Emitter a)
timer val = do
{ emitter, listener } <- H.liftEffect HS.create
_ <-
H.liftAff $ Aff.forkAff
$ forever do
Aff.delay $ Milliseconds 10.0
H.liftEffect $ HS.notify listener val
pure emitter
|
うまくいってる。