Sine animation (Elm 0.15.1)

sine_animation.elm

import Graphics.Collage exposing (..)
import Color exposing (rgb)
import Window
import Time

obj_resolution = 360
waves_amount=6
wave_height=0.1
sine_pct=0.5 -- setting in percantage how big is the part
smoothing_amount=0.14
smooth_pct=1

sine_resolution = sine_pct*obj_resolution
smoothed_resolution = sine_resolution*smoothing_amount

colors = [rgb 55 147 146, rgb 46 73 82, rgb 11 201 199]
phases = [0, degrees 90 , degrees 180]
data = List.map2 (,) colors phases

width i r = {r| width <- i}

waves w h t =
  let radius = (min w h) |> toFloat |> (*) 0.4
      points phase = List.map (wavePoint radius phase t) [0..obj_resolution]
      wave (color, phase) = points phase |> path |> traced (solid color |> width 6)
  in List.map wave data |> group

wavePoint radius phase t i =
  let angle = degrees i -- only works because obj_resolution = 360
      smooth_pct =
        if i < smoothed_resolution
        then i/smoothed_resolution
        else if i > sine_resolution*(1-smoothing_amount) && i <= sine_resolution
        then (sine_resolution-i)/smoothed_resolution
        else if i == obj_resolution
        then 0
        else 1
      
      radiusAddon =
        if i > sine_resolution && i /= obj_resolution
        then 0
        else radius*wave_height*smooth_pct*cos((angle+t)*waves_amount+phase)            
      
  in fromPolar (radius+radiusAddon+phase*3, angle+t)

clock = Signal.foldp (\dt t -> t - dt/650) 0 (Time.fps 30)

black = rgb 16 16 16
scene (w,h) t =
  collage w h
    [ rect (toFloat w) (toFloat h) |> filled black
    , waves w h t
    ]
    
main = Signal.map2 scene Window.dimensions clock