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９番目のステップ。
lesson09
aki:~/breakout$ cp -r lesson08/ lesson09
aki:~/breakout$ cd lesson09/
aki:~/breakout/lesson09$
lesson08 をコピーした lesson09 を用意して続きを始める。
今回は マウス操作
マウスの動作を監視する
マウスの操作を監視するのはキー入力を監視するのよりも簡単です。mousemove (en-US)イベントのリスナーさえあればよいのです。次の行を、他のイベントリスナーの近く、keyup eventのすぐ下に追記してください。
document.addEventListener("mousemove", mouseMoveHandler, false);
キー入力の時のこれを参考にマウスイベントに変更する。
-- mouse event
H.subscribe' \_ ->
eventListener
MET.mousemove
(HTMLDocument.toEventTarget document)
(map HandleMouseMove <<< ME.fromEvent)
パドルの動きをマウスの動きと紐付ける
パドルの位置をカーソルの座標に基づいて更新することができます。次のハンドラ関数は実際にそれを行います。次の関数を自分のコードの、先程追記したコードのすぐ下に追記しましょう。
function mouseMoveHandler(e) { var relativeX = e.clientX - canvas.offsetLeft; if(relativeX > 0 && relativeX < canvas.width) { paddleX = relativeX - paddleWidth/2; } }この関数ではまずビューポートの水平方向のマウスの位置 (e.clientX) からキャンバスの左端とビューポートの左端の距離 (canvas.offsetLeft) をひいてrelativeXの値を導出します。これはキャンバスの左端とマウスカーソルの距離とちょうど同じになります。もしカーソルの相対X座標が0より大きくCanvasの幅より小さいのならば、カーソルはキャンバス内にあります。また、座標paddleX (パドルの左端と紐付けられている) は、パドルの中点で対称に動くようにrelativeXの値からパドルの幅の半分をひいた値に設定されます。
パドルはマウスカーソルの位置を追うようになりますが、動きをCanvasの大きさに制限しているため、両端で消え失せてしまうようなことはありません。
こうしよう。
HandleMouseMove ev -> do
(state :: State) <- H.get
maybeCanvasElement <- H.liftEffect $ htmlElementById canvasId
case Tuple state.maybeCanvas maybeCanvasElement of
Tuple (Just canvas) (Just canvasElement) -> do
{ width: canvasWidth, height: _ } <- H.liftEffect $ Canvas.getCanvasDimensions canvas
offsetLeft <- H.liftEffect $ HTMLElement.offsetLeft canvasElement
let
relativeX = Int.toNumber (ME.clientX ev) - offsetLeft
if between 0.0 canvasWidth relativeX then
H.modify_ \st -> st { dataset { paddleX = relativeX - paddleWidth / 2.0 } }
else
pure unit
_ -> pure unit
結果こうなる。
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.DOM.NonElementParentNode as NonElementParentNode
import Web.Event.Event as E
import Web.HTML (HTMLElement, window)
import Web.HTML.HTMLDocument as HTMLDocument
import Web.HTML.HTMLElement as HTMLElement
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
import Web.UIEvent.MouseEvent (MouseEvent)
import Web.UIEvent.MouseEvent as ME
import Web.UIEvent.MouseEvent.EventTypes as MET
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
, score :: Int
}
data GameSet
= OnGame
| GameOver
| GameClear
type State
= { maybeCanvas :: Maybe CanvasElement
, maybeTimer :: Maybe SubscriptionId
, dataset :: Dataset
}
data Action
= Initialize
| HandleMouseMove MouseEvent
| 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
, score: 0
}
}
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)
-- mouse event
H.subscribe' \_ ->
eventListener
MET.mousemove
(HTMLDocument.toEventTarget document)
(map HandleMouseMove <<< ME.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
case ret.gameset of
GameOver -> do
H.liftEffect $ Window.alert "GAME OVER" =<< window
H.unsubscribe timerSubscriptionId
H.liftEffect $ Location.reload =<< Window.location =<< window
GameClear -> do
H.liftEffect $ Window.alert "YOU WIN, CONGRATULATIONS!" =<< window
H.unsubscribe timerSubscriptionId
H.liftEffect $ Location.reload =<< Window.location =<< window
OnGame -> 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
HandleMouseMove ev -> do
(state :: State) <- H.get
maybeCanvasElement <- H.liftEffect $ htmlElementById canvasId
case Tuple state.maybeCanvas maybeCanvasElement of
Tuple (Just canvas) (Just canvasElement) -> do
{ width: canvasWidth, height: _ } <- H.liftEffect $ Canvas.getCanvasDimensions canvas
offsetLeft <- H.liftEffect $ HTMLElement.offsetLeft canvasElement
let
relativeX = Int.toNumber (ME.clientX ev) - offsetLeft
if between 0.0 canvasWidth relativeX then
H.modify_ \st -> st { dataset { paddleX = relativeX - paddleWidth / 2.0 } }
else
pure unit
_ -> 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
, score: 0
}
}
htmlElementById :: String -> Effect (Maybe HTMLElement)
htmlElementById elementId = do
document <- Window.document =<< window
let
nonElementParentNode = HTMLDocument.toNonElementParentNode document
element <- NonElementParentNode.getElementById elementId nonElementParentNode
pure $ HTMLElement.fromElement =<< element
draw :: CanvasElement -> Dataset -> Effect { nextDataset :: Dataset, gameset :: GameSet }
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
drawScore dataset.score
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
}
drawScore :: Int -> Effect Unit
drawScore score = do
ctx <- Canvas.getContext2D canvas
Canvas.setFont ctx "16px Arial"
Canvas.setFillStyle ctx "#0095DD"
Canvas.fillText ctx ("Score: " <> Int.toStringAs Int.decimal score) 8.0 20.0
nextDataset :: Dataset -> Dimensions -> { nextDataset :: Dataset, gameset :: GameSet }
nextDataset dataset@{ x: x, y: y, dx: dx, dy: dy } c =
let
{ nextBricks: nextBricks, collisioned: collisioned } = nextBricksAndCollisioned
{ nextDy: nextDy, gameset: gameset } = nextDyAndGameset collisioned
nextScore = if collisioned then dataset.score + 1 else dataset.score
nextGameSet = case gameset of
OnGame
| nextScore == brickRowCount * brickColumnCount -> GameClear
_ -> gameset
in
{ nextDataset:
dataset
{ x = x + dx
, y = y + dy
, dx = nextDx
, dy = nextDy
, paddleX = nextPaddleX
, bricks = nextBricks
, score = nextScore
}
, gameset: nextGameSet
}
where
nextPaddleX :: Number
nextPaddleX =
clamp 0.0 (c.width - paddleWidth)
$ 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
nextBricksAndCollisioned :: { nextBricks :: Bricks, collisioned :: Boolean }
nextBricksAndCollisioned = case collisionDetection { x: x, y: y } dataset.bricks of
Nothing ->
{ nextBricks: dataset.bricks
, collisioned: false
}
Just (Tuple key value) ->
{ nextBricks: Map.insert key value dataset.bricks
, collisioned: true
}
nextDx :: Number
nextDx =
if between ballRadius (c.width - ballRadius) (x + dx) then
dx
else
(-dx)
nextDyAndGameset :: Boolean -> { nextDy :: Number, gameset :: GameSet }
nextDyAndGameset collisioned =
let
touchTheCeiling = (y + dy) < ballRadius
touchTheFloor = (y + dy) > (c.height - ballRadius)
touchThePaddle = touchTheFloor && between dataset.paddleX (dataset.paddleX + paddleWidth) (x + dx)
in
case true of
_
| touchTheCeiling -> { nextDy: (-dy), gameset: OnGame }
| touchThePaddle -> { nextDy: (-dy), gameset: OnGame }
| touchTheFloor -> { nextDy: (-dy), gameset: GameOver }
| collisioned -> { nextDy: (-dy), gameset: OnGame }
| otherwise -> { nextDy: dy, gameset: OnGame }
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
パドルをマウスで操作することができました。
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