# Tk_spiral_primes_colors.py

# Tk_spiral_primes_colors.py

from Tkinter import *
from math import sqrt
from random import shuffle as rs

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

COLORS = 'red orange yellow green blue purple grey'.split()*3
color = 0

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

def isPrime(num):
    a=2
    while a <= sqrt(num):
        if num%a < 1:
            return False
        a=a+1
    return num > 1

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

while 1:
    for L in range(2,len(COLORS)/3+1):
        # 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

        canvas.delete('all')
        while 1:
            # If prime... draw
            if isPrime(step):
                color = (color + 1) % L
                t = stepSize * 0.5
                canvas.create_rectangle((x,y,x+t,y+t), fill=COLORS[color], outline='')

            # Move according to state
            x, y = switch(state)

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

            # Are we done?
            if step > totalSteps:
                break
        canvas.update()
    rs(COLORS)