#Sinewheel hip-pocket program in Python/Tkinter
#William Baker, Summer 2004, illiMath04 Program
#Adapted from Math198 course notes by Prof. George Francis
#University of Illinois Urbana-Champaign Dept. of Mathematics

import Tkinter
import math
import time

defaldelay=4 #default delay time

#createLine()
#Draws a red line for the specified coordinates
def createLine(canvas, x0, y0, x1, y1):
   canvas.create_line(x0, y0, x1, y1, fill="red")

#startAnimation()
#Actually performs the animation, called when the start button is
#clicked
def startAnimation():
   dg = .01745 
   dx = 6 
   r = 75 #radius
   x0=80
   y0=240
   x=0
   for x in range(0, 361, dx): 
      # compute values
      xr=x0+r*math.cos(x*dg)
      yr = y0 -r*math.sin(x*dg)
      xx=x0+r+r*x*dg


      createLine(canvas,x0,y0,xr,yr)
      createLine(canvas,xr,yr,xx,yr)
      createLine(canvas,xx,yr,xx,y0)      
     
      canvas.update()
      time.sleep(int(timedelay.get())/20.0)


#clear()
#Clears the cavas, called when clear button is clicked
def clear():
    canvas.delete("all")


window = Tkinter.Tk()
window.title("Sinewheel in Python/Tkinter")

clear_button = Tkinter.Button(window, text = "Clear", command = clear)

start = Tkinter.Button(window, text="Start", command=startAnimation)
delLabel=Tkinter.Label(window, width="15")
delLabel.configure(text="Time Delay= ")
timedelay=Tkinter.StringVar()
timedelay.set(`defaldelay`)
delentry = Tkinter.Entry(window, width="15", textvariable=timedelay)

canvas = Tkinter.Canvas(window, width=640, height=480)


canvas.pack(side="top")
delLabel.pack(side="left")
delentry.pack(side="left")
start.pack(side="right")
clear_button.pack(side = "right")
# start event loop
window.mainloop()