29 lines
1.3 KiB
FSharp
29 lines
1.3 KiB
FSharp
/// m09 app: the whole game wired together as values: streams of actions in, a stream of drawings out.
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module Snake.App
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open Snake.Model
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open Snake.IO
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open Snake.Stream
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let TICK_MS = 150L
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let FRAME_MS = 25L
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// Everything that can happen to the game: a Tick every TICK_MS, and an action for each bound key.
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let classicActions: Stream<Action> =
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Stream.merge (Stream.interval TICK_MS |> Stream.map (fun _ -> Tick)) (Stream.keyDowns |> Stream.choose Input.keyToAction)
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// m10: a Frame every FRAME_MS instead of a Tick; the game itself decides (movesEvery) which frames take a step.
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let speedActions: Stream<Action> =
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Stream.merge (Stream.interval FRAME_MS |> Stream.map (fun _ -> Frame)) (Stream.keyDowns |> Stream.choose Input.keyToAction)
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// Actions folded into game states. startWith puts the initial state first so it is drawn right away.
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let states (seed: uint32) (actions: Stream<Action>) : Stream<GameState> =
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actions |> Stream.scan Game.update (Spawn.newGame seed) |> Stream.startWith (Spawn.newGame seed)
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let render (state: GameState) : IO<unit> = IO.drawScene (View.view state)
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// The whole program as a value: get a seed, then turn the stream of states into a stream of drawings.
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// Nothing runs here; Runtime interprets it.
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let main () : IO<Stream<IO<unit>>> =
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IO.randomSeed () |> IO.map (fun seed -> states seed speedActions |> Stream.map render)
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