Asteroids.elm

module Asteroids where

import Graphics.Collage exposing (..)
import Color exposing (..)

import Types exposing (..)


-- INIT

defaultAsteroid : Asteroid
defaultAsteroid =
  { position = (0,0)
  , speed    = (0,0)
  , angle    = 0
  }


init : List Asteroid
init =
  [ { defaultAsteroid | position = (-120,  80) }
  , { defaultAsteroid | position = ( -65, 110) }
  , { defaultAsteroid | position = (   0, 120) }
  , { defaultAsteroid | position = (  65, 110) }
  , { defaultAsteroid | position = ( 120,  80) }
  ]


-- UPDATE

update : List Asteroid -> Float -> List Asteroid
update asteroids dt =
  let
      upd a = { a | angle = a.angle + dt * 0.1 }
  in
     List.map upd asteroids


-- GRAPHICS

asteroidStyle : LineStyle
asteroidStyle = solid white


draw : List Asteroid -> Form
draw asteroids =
  let
    dr a = move a.position <| rotate a.angle <| outlined asteroidStyle <| ngon 5 13
  in
    group <| List.map dr asteroids