# tk_procedural_slither2.py

# tk_procedural_slither2.py

from tkinter import *
import math

ww = 800
hh = 600
ww0 = ww//2
hh0 = hh//2
L = 400 # snake length by pixel
direction = [0, 0, 0, 0]  # initial direction
degrees = math.radians(359.9999999999)
print(degrees)

root = Tk()
root.title("tk procedural slither")
root.geometry("%dx%d+10+10"%(ww,hh))
canv = Canvas(root, width=ww, height=hh)
canv.pack()

points = []
angles = [angle*0.0002 for angle in range(100, 401)]
angles += [-angle*0.0002 for angle in range(100, 401)]


def movement():
    x = int(ww0 + math.cos(direction[0]) * (math.cos(direction[1]) * (ww0 - 15)))
    y = int(hh0 + math.sin(direction[2]) * (math.sin(direction[3]) * (hh0 - 15)))
    return (x, y)

p = {}
point = movement()
points.append(point)
for i in range(L):
    point = movement()
    points.append(point)
    p[i] = canv.create_line(points, fill="blue", width=3, smooth=True, splinesteps=5)

i = 0
while True:
    canv.delete(p[i])
    points.append(movement())
    points = points[-L:]
    angles.extend([angles.pop(0), angles.pop(7), angles.pop(27), angles.pop(79), angles.pop(101), angles.pop(57)])
    angles.insert(11, angles.pop(99))
    direction = [angles[-i] + direction[i] for i in (0, 1, 2, 3)] # update the direction
    p[i] = canv.create_line(points[-2:], fill="blue", width=3, smooth=True, splinesteps=5)
    i = (i + 1) % L
    canv.update()

root.mainloop()