MDN web docs にある 「そのままのJavaScriptを使ったブロックくずしゲーム」 の7番目のステップ。
lesson07
aki:~/breakout$ cp -r lesson06/ lesson07
aki:~/breakout$ cd lesson07/
aki:~/breakout/lesson07$
lesson06 をコピーした lesson07 を用意して続きを始める。
今回は 衝突検出
衝突検出関数
最初の第一歩として、毎フレーム描画されるたびに全てのブロックを通してループし、ひとつひとつのブロックの位置をボールの座標と比較する衝突検出関数を作成しましょう。コードがより読みやすくなるように、衝突検出のループの中でブロックオブジェクトを保存する変数bを定義します。
function collisionDetection() { for(var c=0; c<brickColumnCount; c++) { for(var r=0; r<brickRowCount; r++) { var b = bricks[c][r]; // いろいろな計算 } } }
もしボールの中央がブロックの1つの座標の内部だったらボールの向きを変えます。ボールの中央がブロックの内部にあるためには次の4つの命題が全て真でなければなりません。
- ボールのx座標がブロックのx座標より大きい
- ボールのx座標がブロックのx座標とその幅の和より小さい
- ボールのy座標がブロックのy座標より大きい
- ボールのy座標がブロックのy座標とその高さの和より小さい
コードに書き下ろしてみましょう。
function collisionDetection() { for(var c=0; c<brickColumnCount; c++) { for(var r=0; r<brickRowCount; r++) { var b = bricks[c][r]; if(x > b.x && x < b.x+brickWidth && y > b.y && y < b.y+brickHeight) { dy = -dy; } } } }
上記のブロックを自分のコードのkeyUpHandler()関数の下に追加してください。
これでどうだ。
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 Control.Monad.ST (for)
import Control.Monad.ST as ST
import Control.Monad.ST.Ref as STRef
import Data.Foldable (any)
import Data.Int as Int
import Data.Map (Map)
import Data.Map as Map
import Data.Maybe (Maybe(..))
import Data.Time.Duration (Milliseconds(..))
import Data.Traversable (for_)
import Data.Tuple (Tuple(..))
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.Location as Location
import Web.HTML.Window as Window
import Web.UIEvent.KeyboardEvent as KE
import Web.UIEvent.KeyboardEvent.EventTypes as KET
canvasId :: String
canvasId = "myCanvas"
paddleHeight = 10.0 :: Number
paddleWidth = 75.0 :: Number
ballRadius = 10.0 :: Number
brickRowCount = 3 :: Int
brickColumnCount = 5 :: Int
brickWidth = 75 :: Int
brickHeight = 20 :: Int
brickPadding = 10 :: Int
brickOffsetTop = 30 :: Int
brickOffsetLeft = 30 :: Int
newtype BricksIndex
= BricksIndex { row :: Int, column :: Int }
derive newtype instance showBricksIndex :: Show BricksIndex
derive newtype instance ordBricksIndex :: Ord BricksIndex
derive newtype instance eqBricksIndex :: Eq BricksIndex
newtype Brick
= Brick { x :: Number, y :: Number }
derive newtype instance showBrick :: Show Brick
type Bricks
= Map BricksIndex Brick
type Dataset
= { x :: Number
, y :: Number
, dx :: Number
, dy :: Number
, paddleX :: Number
, leftPressed :: Boolean
, rightPressed :: Boolean
, bricks :: Bricks
}
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
, bricks: Map.empty
}
}
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
, bricks: Map.empty
}
}
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
bricks <- pure $ coordinateBricks dataset.bricks
drawBricks bricks
pure
let
collisioned = collisionDetection { x: dataset.x, y: dataset.y } bricks
dy' = if collisioned then (-dataset.dy) else dataset.dy
in
nextDataset dataset { dy = dy', bricks = bricks } 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
drawBricks :: Bricks -> Effect Unit
drawBricks bricks =
for_ bricks \(Brick brick) -> do
ctx <- Canvas.getContext2D canvas
Canvas.beginPath ctx
Canvas.rect ctx
{ x: brick.x
, y: brick.y
, width: Int.toNumber brickWidth
, height: Int.toNumber brickHeight
}
Canvas.setFillStyle ctx "#0095DD"
Canvas.fill ctx
Canvas.closePath ctx
coordinateBricks :: Bricks -> Bricks
coordinateBricks bricks =
ST.run do
var <- STRef.new bricks
for 0 brickColumnCount \c ->
for 0 brickRowCount \r ->
let
key = BricksIndex { row: r, column: c }
value = Brick (coord key)
in
STRef.modify (Map.insert key value) var
STRef.read var
where
coord :: BricksIndex -> { x :: Number, y :: Number }
coord (BricksIndex { row: r, column: c }) =
{ x: (c * (brickWidth + brickPadding)) + brickOffsetLeft # Int.toNumber
, y: (r * (brickHeight + brickPadding)) + brickOffsetTop # Int.toNumber
}
collisionDetection :: { x :: Number, y :: Number } -> Bricks -> Boolean
collisionDetection ball bricks =
let
(xs :: Array (Tuple BricksIndex Brick)) = Map.toUnfoldableUnordered bricks
in
any collisioned xs
where
collisioned :: Tuple BricksIndex Brick -> Boolean
collisioned (Tuple _ (Brick brick)) =
between brick.x (brick.x + (Int.toNumber brickWidth)) ball.x
&& between brick.y (brick.y + (Int.toNumber brickHeight)) ball.y
nextDataset :: Dataset -> Dimensions -> { nextDataset :: Dataset, gameover :: Boolean }
nextDataset dataset 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
期待通り動いている。
衝突検出を有効にする
いろいろやってこうなった。
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 Control.Monad.ST (for)
import Control.Monad.ST as ST
import Control.Monad.ST.Ref as STRef
import Data.Array as Array
import Data.Generic.Rep (class Generic)
import Data.Int as Int
import Data.Map (Map)
import Data.Map as Map
import Data.Maybe (Maybe(..))
import Data.Show.Generic (genericShow)
import Data.Time.Duration (Milliseconds(..))
import Data.Traversable (for_)
import Data.Tuple (Tuple(..))
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.Location as Location
import Web.HTML.Window as Window
import Web.UIEvent.KeyboardEvent as KE
import Web.UIEvent.KeyboardEvent.EventTypes as KET
canvasId :: String
canvasId = "myCanvas"
paddleHeight = 10.0 :: Number
paddleWidth = 75.0 :: Number
ballRadius = 10.0 :: Number
brickRowCount = 3 :: Int
brickColumnCount = 5 :: Int
brickWidth = 75 :: Int
brickHeight = 20 :: Int
brickPadding = 10 :: Int
brickOffsetTop = 30 :: Int
brickOffsetLeft = 30 :: Int
data BrickStatus
= InActive
| Active
derive instance genericBrickStatus :: Generic BrickStatus _
derive instance eqBrickStatus :: Eq BrickStatus
instance showBrickStatus :: Show BrickStatus where
show = genericShow
newtype BricksIndex
= BricksIndex { row :: Int, column :: Int }
derive newtype instance showBricksIndex :: Show BricksIndex
derive newtype instance ordBricksIndex :: Ord BricksIndex
derive newtype instance eqBricksIndex :: Eq BricksIndex
newtype Brick
= Brick { x :: Number, y :: Number, status :: BrickStatus }
derive newtype instance showBrick :: Show Brick
type Bricks
= Map BricksIndex Brick
type Dataset
= { x :: Number
, y :: Number
, dx :: Number
, dy :: Number
, paddleX :: Number
, leftPressed :: Boolean
, rightPressed :: Boolean
, bricks :: Bricks
}
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
, bricks: Map.empty
}
}
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
, bricks: Map.empty
}
}
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
bricks <- pure $ coordinateBricks dataset.bricks
drawBricks bricks
pure $ nextDataset dataset { bricks = bricks } 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
drawBricks :: Bricks -> Effect Unit
drawBricks bricks =
for_ bricks case _ of
(Brick brick)
| brick.status == Active -> do
ctx <- Canvas.getContext2D canvas
Canvas.beginPath ctx
Canvas.rect ctx
{ x: brick.x
, y: brick.y
, width: Int.toNumber brickWidth
, height: Int.toNumber brickHeight
}
Canvas.setFillStyle ctx "#0095DD"
Canvas.fill ctx
Canvas.closePath ctx
_ -> pure unit
coordinateBricks :: Bricks -> Bricks
coordinateBricks bricks =
ST.run do
var <- STRef.new bricks
for 0 brickColumnCount \c ->
for 0 brickRowCount \r ->
let
key = BricksIndex { row: r, column: c }
value = coord Active key
in
STRef.modify (Map.insertWith modify key value) var
STRef.read var
where
modify :: Brick -> Brick -> Brick
modify (Brick current) (Brick new) = Brick new { status = current.status }
coord :: BrickStatus -> BricksIndex -> Brick
coord status (BricksIndex { row: r, column: c }) =
Brick
{ x: (c * (brickWidth + brickPadding)) + brickOffsetLeft # Int.toNumber
, y: (r * (brickHeight + brickPadding)) + brickOffsetTop # Int.toNumber
, status: status
}
nextDataset :: Dataset -> Dimensions -> { nextDataset :: Dataset, gameover :: Boolean }
nextDataset dataset 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
collisionedBrick = collisionDetection { x: x, y: y } dataset.bricks
{ nextBricks: nextBricks, collisioned: collisioned } = case collisionedBrick of
Nothing ->
{ nextBricks: dataset.bricks
, collisioned: false
}
Just (Tuple key value) ->
{ nextBricks: Map.insert key value dataset.bricks
, collisioned: true
}
{ 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 }
| collisioned -> { nextDy: (-dy), gameover: false }
| 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
, bricks = nextBricks
}
, gameover: gameover
}
where
collisionDetection :: { x :: Number, y :: Number } -> Bricks -> Maybe (Tuple BricksIndex Brick)
collisionDetection ball bricks =
Array.head
$ map inactivate
$ Map.toUnfoldableUnordered
$ Map.filterWithKey collisioned bricks
where
inactivate :: Tuple BricksIndex Brick -> Tuple BricksIndex Brick
inactivate (Tuple idx (Brick brick)) =
Tuple
idx
$ Brick
brick { status = InActive }
collisioned :: BricksIndex -> Brick -> Boolean
collisioned _ (Brick brick) = case brick.status of
InActive -> false
Active
| between brick.x (brick.x + (Int.toNumber brickWidth)) ball.x
&& between brick.y (brick.y + (Int.toNumber brickHeight)) ball.y -> true
| otherwise -> false
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
ボールをぶつけたブロックが消せました。
GitHubリポジトリ
コードはGitHub上にあります。
https://github.com/ak1211/breakout
まだつづく
よてい