# Tk_random_ref_scroll_art.py

# Tk_random_ref_scroll_art.py

from tkinter import *
from PIL import Image, ImageTk
import math
import random

ww = 600
hh = 600

def draw():
    image.putdata(rgb)
    photo = ImageTk.PhotoImage(image)
    canvas.create_image(0,0,image=photo,anchor=NW)
    canvas.update()


root = Tk()
root.title("Tk_random_ref_scroll_art")
root.geometry("%dx%d+0+0"%(ww,hh))

canvas = Canvas(root, width=ww, height=hh)
canvas.pack()

image = Image.new("RGB", (ww,hh), (255,255,255))

black = [(0,)*3]
white = [(255,)*3]

zzz = [i for i in range(10)]
zzz = zzz[1:-1] + zzz[::-1]

ref = []
while len(ref) < ww+5:
    ref.extend(zzz)
ref = ref[:ww+2]

rgb = white*(ww*hh)

while 1:
    ttt = []
    buf = []
    iii = 1
    while len(ttt) < ww:
        t = 0
        for i in [iii-1,iii,iii+1]:
            t += ref[i]
        t = t//3
        t = random.randint(t-3,t) % 100
        buf += [t]
        if t < 7:
            ttt += black
        else:
            ttt += white
        iii += 1
    ref = buf * 2
    ref = [ref[-1]] + ref
    rgb.extend(ttt[:ww])
    rgb = rgb[-ww*hh:]
    draw()