Nested noise with Nim

noise.nim

import math
import tables
import random
import algorithm

import csfml
import perlin

randomize()

let
  size = 800
  scale = 20.0
  img = newImage(cint size, cint size)
  red_noise = newNoise()
  green_noise = newNoise()
  blue_noise = newNoise()

var
  window = newRenderWindow(videoMode(cint size, cint size), "maxnoise")

proc getNoiseValue(n: Noise, x, y: int): float =
  let
    nx = float(x) / scale
    ny = float(y) / scale
  n.simplex(nx, ny)

proc redColor(diff: float): Color =
  color(int 255 * diff, 0, 0)

proc greenColor(diff: float): Color =
  color(0, int 255 * diff, 0)

proc blueColor(diff: float): Color =
  color(0, 0, int 255 * diff)

proc getColorValue(x, y: int): Color =
  let
    rn = getNoiseValue(red_noise, x, y)
    gn = getNoiseValue(green_noise, x, y)
    bn = getNoiseValue(blue_noise, x, y)

  var
    map = initTable[float, proc(diff:float): Color]()
    values = @[rn, gn, bn]

  map[rn] = redColor
  map[gn] = greenColor
  map[bn] = blueColor

  values.sort()

  if rn > gn:
    result = redColor(rn - gn)
  elif rn > bn:
    result = redColor(rn - bn)
  elif gn > rn:
    result = greenColor(gn - rn)
  elif gn > bn:
    result = greenColor(gn - bn)
  elif bn > rn:
    result = blueColor(bn - rn)
  elif bn > gn:
    result = blueColor(bn - gn)


for x in 0..size:
  for y in 0..size:
    let cvalue = getColorValue(x, y)
    img.setPixel(cint x, cint y, cvalue)

# copy image into texture and create a sprite
let tex = newTexture(img, rect(0, 0, size, size))
let spr = newSprite(tex)

# draw the sprite
window.clear(Black)
window.draw(spr)

# save to file
discard tex.copyToImage().saveToFile("maxnoise.png");

while window.open:
  var event: Event
  while window.pollEvent(event):
    let
      escape = event.kind == EventType.KeyPressed and event.key.code == KeyCode.Escape
      closed = event.kind == EventType.Closed

    if escape or closed:
      window.close()
    window.display()