# -*- coding: utf-8 -*-
# Copyright © 2017 Kevin Thibedeau
# Distributed under the terms of the MIT license
import math
from math import sin, pi
import colorsys
def sinebow(hue):
'''Adapted from http://basecase.org/env/on-rainbows'''
hue = -(hue + 0.5) # Start at red rotating clockwise
rgb = sin(pi * hue), sin(pi * (hue + 1.0/3.0)), sin(pi * (hue + 2.0/3.0))
return tuple(int(255 * c**2) for c in rgb)
def distinct_color_sequence(hue=0.0):
# Hue is normalized from 0-1.0 for one revolution
phi = (1 + 5**0.5) / 2
golden_angle = phi #1.0 / phi**2
#print('# GA:', math.degrees(golden_angle), phi)
while(True):
yield sinebow(hue)
hue += golden_angle
def lighten(rgb, p):
h,l,s = colorsys.rgb_to_hls(*(c / 255.0 for c in rgb))
l = p + l - p*l
return tuple(int(c * 255) for c in colorsys.hls_to_rgb(h,l,s))
if __name__ == '__main__':
import PIL
from PIL import Image, ImageDraw
cs = distinct_color_sequence()
im = Image.new('RGB',(1024,10))
d = ImageDraw.Draw(im)
for i in range(256):
hue = i / 256
#r,g,b = sinebow(hue)
r,g,b = next(cs)
d.line([(i*4,0), (i*4,9)], (r,g,b), width=4)
im.save('sinebow_rand.png')
im = Image.new('RGB',(256,10))
d = ImageDraw.Draw(im)
for i in range(256):
hue = i / 256
r,g,b = sinebow(hue)
d.line([(i,0), (i,9)], (r,g,b))
im.save('sinebow.png')
