# Tk_2D_ripples.py

# Tk_2D_ripples.py

from tkinter import *
import time
from PIL import Image, ImageTk

tx =  time.time
ww = 180
hh = 180

root = Tk()
root.title("Tk_2D_ripples")
root.geometry("%dx%d+-6+-2"%(ww,hh))
canvas = Canvas(width=ww, height=hh)
canvas.pack()

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

def motion(event):
    mouse_pos.append((event.x, event.y))
root.bind('<B1-Motion>', motion)

cols = ww
rows = hh

#dampening = how fast the ripple effect stops.
dampening = 0.99999

#Arrays that hold the colors of the screen.
rgb = []
xy = {}
for j in range(0,rows):
    for i in range(0,cols):
        xy[i,j] = len(rgb)
        rgb += [(0)]
current = rgb[:]
previous = rgb[:]

mouse_pos = []
image = Image.new("RGB", (ww,hh))

def draw():
    image.putdata(rgb)
    photo = ImageTk.PhotoImage(image)
    canvas.create_image(0,0,image=photo,anchor=NW)
    canvas.update()

def sides(i,j):
    return ([i-1,j],[i+1,j],[i,j-1],[i,j+1])

#Mainloop
while 1:
    for i in range(1,cols-1):
        for j in range(1,rows-1):
            if mouse_pos:
                x,y = mouse_pos.pop(0)
                for x2,y2 in  sides(x,y):
                    try:
                        t = xy[x2,y2]
                        previous[t] = 500
                    except:
                        0

            t = xy[i,j]

            sides2 = [previous[xy[x,y]] for x,y in sides(i,j)]
            current[t] = sum(sides2)*0.5-current[t]
            current[t] *= dampening

            val = min(255, max(0, int(current[t])))
            rgb[t] = (val,val,val)

    # print(tx)

    draw()

    # Switching the arrays
    previous, current = current, previous