我正在尝试为4人游戏创建自定义键盘控件.现在,键是这样预先确定的:
type Orient = { x:Int, y:Int }
type GameInput = { space:Bool, delta:Time, so1:Orient, so2:Orient, so3:Orient,
so4:Orient, amount:Int }
gameInput : Signal GameInput
gameInput =
let sampledInput = sampleOn delta
<| GameInput <~ Keyboard.space
~ delta
~ Keyboard.arrows
~ Keyboard.wasd
~ Keyboard.directions (toCode 'O')
(toCode 'L')
(toCode 'K')
(toCode 'M')
~ Keyboard.directions (toCode 'Y')
(toCode 'H')
(toCode 'G')
(toCode 'J')
~ amountPlayers.signal
in lift (Debug.watch "input") sampledInput
我创建了(对于每个玩家)表单的输入:
type CustomKeys = { up:Char, down:Char, left:Char, right:Char }
customKeys2 : Signal CustomKeys
customKeys2 = CustomKeys <~ ck2up.signal
~ ck2down.signal
~ ck2left.signal
~ ck2right.signal
ck2up : Input Char
ck2up = input 'W'
ck2down : Input Char
ck2down = input 'S'
ck2left : Input Char
ck2left = input 'A'
ck2right : Input Char
ck2right = input 'D'
其他地方的处理程序将根据玩家的需要调整输入值.但是我很难弄清楚如何将这些值插入到Keyboard.directions的参数中.
我试过直接将参数提升到Keyboard.directions:
~ Keyboard.directions <~ ...
任何结果都将成为信号的信号,不能被提升到GameInput(正确).
我已经尝试将chars作为参数传递给gameInput:
gameInput2 : Signal GameInput
gameInput2 = gameInput <~ customKeys2
gameInput : CustomKeys -> Signal GameInput
gameInput { up,down,left,right } = GameInput <~ Keyboard.directions (toCode up)
(toCode down)
(toCode left)
(toCode right)
现在,gameInput2将产生一个信号信号.
我的最后一个想法是组合信号,但这对我来说似乎不是一个选项,因为我希望一个信号依赖于另一个信号.
最佳答案 直接使用Keyboard.directions是行不通的.问题是,在游戏开始时,可以更改密钥,以便您有一些信号字符.而Keyboard.direction从“普通类型”变为“信号类型”.所以你不能解除它.
但您也可以访问当前按下的键,Keyboard.keysDown.我抬头查看了implementation of Keyboard.directions
,我认为你可以在Elm中重新创建它,它采用Signal Int参数.
这是普通Keyboard.directions的Elm实现:
directions : Int -> Int -> Int -> Int -> Signal { x : Int, y : Int }
directions up down left right =
(\kd ->
List.filter (\ky -> List.member ky [up,down,left,right]) kd |>
List.foldl (\ky st -> if | ky == up -> { st | y <- st.y + 1 }
| ky == down -> { st | y <- st.y - 1 }
| ky == left -> { st | x <- st.x - 1 }
| ky == right -> { st | x <- st.x + 1 }
) {x=0,y=0}
) <~ Keyboard.keysDown
这是你想要使用的实现:
directions : Signal Int -> Signal Int -> Signal Int -> Signal Int -> Signal { x : Int, y : Int }
directions up down left right =
(\u d l r kd ->
List.filter (\ky -> List.member ky [u,d,l,r]) kd |>
List.foldl (\ky st -> if | ky == u -> { st | y <- st.y + 1 }
| ky == d -> { st | y <- st.y - 1 }
| ky == l -> { st | x <- st.x - 1 }
| ky == r -> { st | x <- st.x + 1 }
) {x=0,y=0}
) <~ up ~ down ~ left ~ right ~ Keyboard.keysDown
随意重构,我只是快速地将这些代码一起攻击,因此它对于单个函数来说太大了.