# Tk_rgb_sq_spiral.py

# Tk_rgb_sq_spiral.py

from Tkinter import *
from math import sqrt

def oRGB(rgb): # pass
    r,g,b = rgb
    return "#%02x%02x%02x" % (r,g,b)

ww = 600
hh = 600
root = Tk()
root.title("# Tk_rgb_sq_spiral")
root.geometry("%dx%d+0+0"%(ww,hh))
canvas = Canvas(root, width=ww, height=hh)
canvas.grid()

def switch(state):
    return {
        0 : (x + stepSize, y),
        1 : (x, y - stepSize),
        2 : (x - stepSize, y),
        3 : (x, y + stepSize),
    }[state]

# to record spiral
xy = []

# set up spiral
step = 1
state = 0
numSteps = 1
turnCounter = 1
stepSize = 5
cols = ww / stepSize
rows = hh / stepSize
totalSteps = cols * rows
x = ww / 2
y = hh / 2

o256 = range(0,256,10)
rgb = [(r,g,b) for r in o256 for g in o256 for b in o256][::-1]

while 1:
    xy.append((x,y))

    # Change state
    if step % numSteps == 0:
        state = (state + 1) % 4
        turnCounter += 1
        if turnCounter % 2 == 0:
            numSteps += 1
    step += 1
    x, y = switch(state)

    # Are we done?
    if step > totalSteps:
        break

step = 20

for x,y in xy:
    t = stepSize
    color = oRGB(rgb[step])
    canvas.create_rectangle((x,y,x+t,y+t), fill=color, outline='')
    step += 1
canvas.update()