# Tk_cave_gif.py

# Tk_cave_gif.py

from Tkinter import *
import random
from PIL import Image, ImageTk


size = 300
light = 255
dark = 0
colorBalance = 0.5
area = [-1,0,1]

root = Tk()
root.title("Tk cave_gif")
xm=ym=size

canvas = Canvas(root, width=xm, height=ym)
canvas.grid()

screenShotsAtIterations = [0] + [2**i for i in range(10,21)]
iterations = screenShotsAtIterations[-1]
neighbours = [(i,j) for i in area for j in area if i!=0 or j!=0]
neighboursCount = len(neighbours)
rnd = random.Random()
rnd.seed(0)
image = Image.new('L',(size,size), light)
pixel = image.load()

for x in range(size):
    for y in range(size):
        pixel[x,y] = rnd.random() < colorBalance and light or dark

c = 1
for i in range(iterations+1):
    if (i in screenShotsAtIterations):
        filename = 'cave_' + str(c) + '.png'
        c += 1
        #image.save(filename)
        print filename
        '''
        if i == screenShotsAtIterations[-1]:
            image.resize((size*4,size*4)).save('cave_final_big.png')
        '''

        imgTk = ImageTk.PhotoImage(image)
        canvas.create_image((0,0),image=imgTk,anchor=NW)
        root.update()

    x = rnd.randrange(size)
    y = rnd.randrange(size)
    currentColor = pixel[x,y]
    darkNeighbours = sum(pixel[(x+i)%size,(y+j)%size] == dark for (i,j) in neighbours)
    lightNeighbours = neighboursCount - darkNeighbours
    if darkNeighbours > lightNeighbours:
        pixel[x,y] = dark
    elif lightNeighbours > darkNeighbours:
        pixel[x,y] = light

# the code above can generate a set of still images,
# which can be combined to an animated gif using this imagemagick command line:
# convert cave_1*.png -set delay 15 -reverse cave_1*.png -set delay 25 -loop 0 cave.gif