# Tk_ani_ribbons.py

# Tk_ani_ribbons.py

from math import cos,sin,pi,radians
import time
import random

r=random.randint
now=time.time

try:
    import tkinter as tk
except:
    import Tkinter as tk

root=tk.Tk()
root.title("Tk Animating Ribbons")

go=0

ww=640
hh=640

canvas=tk.Canvas(root,width=ww,height=hh)
canvas.pack(fill="both",expand=True)

do360={}
for angle in range(0,360):
    a=cos(radians(angle))
    b=sin(radians(angle))
    do360[angle]=(a,b)
def i360(angle):
    return do360[angle%360]

# for fluidity
wave={}
sp={}
def WAVE(span):
    global polar
    polar *= -1
    incr=360.0/span
    for angle in range(0,span):
        i=cos(radians((angle*incr)*polar))
        yield i

colors='darkorange blue'.split()
marks={}

def make_line(i,z):
    x0,y0,x1,y1=(i360(z)+i360(z))
    x0*=r0
    y0*=r0
    x1*=r1
    y1*=r1
    t=x+xm+x0,y+ym+y0,x+xm+x0+x1,y+ym+y0+y1
    if go:
        t=canvas.create_line(t,width=2,fill=colors[i])
    marks[i].append(t)

xm,ym=ww/2,hh/2
L=800
for i in (0,1):
    x=y=0
    marks[i]=[]
    r0=100
    r1=300
    marks[i,'z']=r(0,359)
    for z in range(0,L,4):
        make_line(i,z)

def get_wave(span):
    global wave
    while 1:
        try:
            zzz=next(wave)*span/5.0
            break
        except:
            wave=WAVE(span)
    return zzz

go=1
polar = -1
rnd_rotate = 180
while go:
    time=now()+0.05
    for i in [0]:
        canvas.delete(marks[i][0])
        marks[i] = marks[i][-L:]
        z=marks[i,'z']
        x=get_wave(600)
        y=get_wave(500)
        r0=get_wave(300)+100
        r1=get_wave(200)+300
        z += 1
        z %= 360
        marks[i,'z']=z
        if z == rnd_rotate:
            polar = random.choice((1,-1))
            rnd_rotate = (r(20,340)+z)%360
        canvas.update()
        make_line(i,z)
    while time > now():
        0

tk.mainloop()