# tk_refracted_water.py

import tkinter as tk
import math
import random

root = tk.Tk()
canvas = tk.Canvas(root, width=600, height=600)
canvas.pack()

zzz = []

def shading(normal_vector, light_direction):
	# calculate the angle between the normal vector and the light direction
	dot_product = sum([a*b for a,b in zip(normal_vector, light_direction)])
	dot_product = max(0, min(1, (dot_product + 1000) * 0.0005))
	angle = math.acos(dot_product)
	# use the angle to determine the shade of blue
	shade = int(255 * 2 * (1 - angle / math.pi))
	if shade > 255:
		shade -= 255
		rgb = (shade, shade, 255)
	else:
		rgb = (0, 0, shade)
	return "#{:02x}{:02x}{:02x}".format(*rgb)
	
def vector(x, y):
	if (x, y) in vectors:
		return vectors[x, y]
	else:
		x1 = x + random.randint(-7, 7)
		y1 = y + random.randint(-7, 7)
		z1 = random.randint(0, 20)
		vectors[x, y] = x1, y1, z1
		return x1, y1, z1
	
triangles = []
depths = []
vectors = {}
t = 0
for i in range(-1, 26):
	for j in range(-1, 26):
		x = i * 24
		y = j * 24
		x1, y1, z1 = vector(x, y)
		x2, y2, z2 = vector(x + 24, y)
		x3, y3, z3 = vector(x, y + 24)
		vectors[t] = [(x, y), (x + 24, y), (x, y + 24)]
		t += 1
		triangles.append([x1, y1, x2, y2, x3, y3])
		depths.append([z1, z2, z3])
		
		x1 = x2
		y1 = y2
		x2, y2, z2 = vector(x + 24, y + 24)
		vectors[t] = [(x + 24, y + 24)]
		t += 1
		triangles.append([x1, y1, x2, y2, x3, y3])
		depths.append([z1, z2, z3])
		
# set the light direction
light_direction = (1, 1, 1)

while 1:
	canvas.delete('all')
	for i in range(len(triangles)):
		x1, y1, x2, y2, x3, y3 = triangles[i]
		z1, z2, z3 = depths[i]
		# calculate the normal vector using the cross product of the two vectors of the triangle
		a = [x2-x1, y2-y1, z2-z1]
		b = [x3-x1, y3-y1, z3-z1]
		normal_vector = [a[1]*b[2] - a[2]*b[1], a[2]*b[0] - a[0]*b[2], a[0]*b[1] - a[1]*b[0]]
		# call the shading function with the normal vector and light direction
		shade = shading(normal_vector, light_direction)
		# create the polygon with the returned fill color
		canvas.create_polygon(x1, y1, x2, y2, x3, y3, outline='', fill=shade)
	root.update()