# tk_caustic_lines.py

# tk_caustic_lines.py

from tkinter import *
from PIL import Image, ImageTk, ImageFilter, ImageDraw, ImageEnhance
import copy

ww = 256
hh = 256
cx, cy = ww//2, hh//2

def rgb2hex(r,g,b):
    return '#%02X%02X%02X'%(r,g,b)

rgb = range(0, 256, 10)
colors = [rgb2hex(z, z, z) for z in rgb]

img = Image.new('RGB', (ww, hh), (0, 0, 0))
draw = {}
draw[0] = ImageDraw.Draw(img)
blur_radius = 0.03 * min(img.size)

def display(new_img):
    tkimg = ImageTk.PhotoImage(new_img)
    canvas.create_image((cx, cy), image=tkimg)
    canvas.update()

root = Tk()
root.title("tk_caustic_lines")
root.geometry("%dx%d+10+10"%(ww,hh))
canvas = Canvas(root, width=ww, height=hh, bg='white')
canvas.pack(side=LEFT, fill=BOTH, expand=True)

sz = 16
span = ww//sz
c = 0
xy = range(0, sz*span, sz)

sharpening_masks = []

while 1:
    for y in xy:
        c = (c + 2) % 11
        for x in xy:
            color = colors.pop(c)
            colors.append(color)
            draw[0].rectangle((x, y, x+sz, y+sz), fill=color, outline=color)
            c = (c + 3) % 11
    draw['target'] = img.filter(ImageFilter.GaussianBlur(radius=blur_radius)).convert("L").point(lambda x: 0 if 120 < x < 128 else 255)
    display(draw['target'])
    if draw['target'] not in sharpening_masks[:1]:
        sharpening_masks += [draw['target']]
    else:
        break
print("grayscale masks created")