Colorful display pic with HUSL

generate-avatar.py

import math
import png

from husl import *

def mix(h1, h2, t):
    return h1 * t + h2 * (1 - t)

def spiral(radius, degree, number):
    n = 1.0 / number
    curvy_radius = (radius + degree) % 1
    return ((curvy_radius % n) / n)

def spiral_cart(cx, cy, number):
    radius = math.sqrt(cx ** 2 + cy ** 2)
    degree_rad = math.atan2(cy, cx) 
    degree = degree_rad / 2.0 / math.pi + 0.5
    return spiral(radius, degree, number)

def get_color(x, y):
    cx = x - 0.5
    cy = y - 0.5

    criss = (x + y) / 2
    cross = ((1 - x) + y) / 2

    radius = math.sqrt(cx ** 2 + cy ** 2)
    degree_rad = math.atan2(cy, cx) 
    degree = degree_rad / 2.0 / math.pi

    spiral1 = spiral_cart(cx, cy, 10)
    spiral2 = spiral_cart(cx, cy, 9)

    color1 = criss
    color2 = cross
    color3 = degree
    s = 1
    l = mix(0.5, criss, spiral2)
    h = mix(color2, color3, spiral1)
    h = (h + color1) % 1

    return (360 * h, 100 * s, 100 * l)

def write_png(func, height, width):
    p = []
    for i in range(height):
        row = []
        for j in range(width):
            row.extend(rgb_prepare(husl_to_rgb(*func(
                float(j) / width,
                float(i) / height))))
        p.append(row)

    f = open('avatar.png', 'wb')
    w = png.Writer(width, height)
    w.write(f, p)
    f.close()

if __name__ == "__main__":
    write_png(get_color, 300, 300)