# tk_water_caustic_ani.py

# tk_water_caustic_ani.py

from tkinter import *
from PIL import Image, ImageTk, ImageFilter, ImageDraw
from math import sin, cos, pi
import random

ww = 384
hh = 384
cx, cy = ww//2, hh//2

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

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

rgb = range(0, 256, 50)
colors = [rgb2hex(r, g, b) for r in rgb for g in rgb for b in rgb]

img = Image.new('RGB', (ww, hh), (0, 0, 0))
draw = {}
for k in (0, 1, 2, 3):
    draw[k] = ImageDraw.Draw(img)
blur_radius = 0.04 * min(img.size)

# set the minimum and maximum colors of the water
min_color = (0, 80, 180)
max_color = (0, 210, 250)

# create a custom color palette for interpolation
palette = [min_color] * 3
for i in range(0,253,2):
        g = min_color[1] + (max_color[1] - min_color[1]) * i // 245
        b = min_color[2] + (max_color[2] - min_color[2]) * i // 245
        palette.append((0, g, b))
for i in range(253,256):
        palette.append((255, 255, 255))
palette = palette[1:-1]+palette[::-1]

Lc = len(palette)

canvas = Canvas(root, width=ww, height=hh, bg='white')
canvas.pack(side=LEFT, fill=BOTH, expand=True)

def display():
    tkimg = ImageTk.PhotoImage(draw['source'])
    canvas.create_image((cx, cy), image=tkimg)
    canvas.update()

sz = 16
c = 0
xy = range(0, 512, sz)
for y in xy:
    for x in xy:
        c = random.randint(0, 50)
        color = colors.pop(c)
        colors.append(color)
        draw[1].rectangle((x, y, x+sz, y+sz), fill=color, outline=color)
draw['source'] = img.filter(ImageFilter.GaussianBlur(radius=blur_radius))
source = {}
target = {}
for y in range(hh):
    for x in range(ww):
        source[x,y] = draw['source'].getpixel((x, y))

def wave_transition(x, y, alpha):
    source_color = source[x, y]
    target_color = draw['target'].getpixel((x, y))

    r = int((1 - alpha) * source_color[0] + alpha * target_color[0])
    g = int((1 - alpha) * source_color[1] + alpha * target_color[1])
    b = int((1 - alpha) * source_color[2] + alpha * target_color[2])

    # apply the custom color palette
    color = int(r + g + b) % Lc
    draw['source'].putpixel((x, y), palette[color])


def waves():
    alpha = 0.1
    while alpha < 0.8:
        for y in range(hh):
            for x in range(ww):
                wave_transition(x, y, alpha)
        alpha += 0.1
        display()

    for y in range(hh):
        for x in range(ww):
            target_color = draw['target'].getpixel((x, y))
            wave_transition(x, y, alpha=0.9)
            source[x, y] = target_color # fastest solution I can think of
    display()

while 1:
    for y in xy:
        c = (c + 1) % 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 + 1) % 11
    draw['target'] = img.filter(ImageFilter.GaussianBlur(radius=blur_radius))

    waves()