Nautic

Nautic.elm

import Html (..)
import Html.Attributes (..)
import Html.Events (..)
import Signal
import Graphics.Collage (collage, filled, rect, toForm, move, rotate)
import Graphics.Element (Element, image)
import Window
import Color (..)
import Keyboard (arrows)
import Text (asText)
import Time (fps, Time)

type alias Model = { speed: Int, dir: Float, rpms: Int, pos: (Float, Float) }

defaultModel = { speed = 0, dir = 0.0, rpms = 0, pos = (0.0, 0.0) }

type alias Action = { x:Int, y:Int }

pivot : Action -> Model -> Model
pivot action model = { model | dir <- model.dir - 3 * (toFloat action.x) }

motor action model = { model | rpms <- model.rpms + action.y }

motion model = 
  let 
    mod = toFloat model.rpms
    x = mod * (cos (degrees model.dir))
    y = mod * (sin (degrees model.dir))
  in
    { model | pos <- addV model.pos (x, y) }

addV (x,y) (x',y') = (x+x', y+y')

update : (Float, Action) -> Model -> Model
update (dt, action) = pivot action >> motor action >> motion

sea w h = rect (toFloat w) (toFloat h) |> filled blue 
boat w h model = image (w*2 // 20) (h // 20) "boat_hatoup_top.png" |> toForm |> rotate (degrees (model.dir + 180)) |> move model.pos

inspect = asText >> toForm 

view : (Int, Int) -> Model -> Element
view (w,h) model = collage w h 
  [
    sea w h
  , boat w h model
  , inspect model |> move(0, 200)
  , inspect (cos (degrees model.dir)) |> move(0,300)
  , inspect (sin (degrees model.dir)) |> move(0,290)
  ]

main : Signal Element
main = Signal.map2 view Window.dimensions model

input = let delta = Signal.map (\t -> t/20) (fps 25)
        in  Signal.sampleOn delta (Signal.map2 (,) delta arrows)

model : Signal Model
model =
  Signal.foldp update defaultModel input