Spirograph.pyde

#from __future__ import division

#spirograph.pyde

r1 = 300.0 #radius of big circle
r2 = 105.0 #radius of circle 2
r3 = 5.0   #radius of drawing “dot”
#location of big circle:
x1 = 0
y1 = 0
t = 0 #time variable
points = [] #empty list to put points in
prop = 0.8

def setup():
    size(600,600)
    
def draw():
    global r1,r2,x1,y1,t,prop,points
    translate(width/2,height/2)
    background(255)
    noFill()
    #big circle
    stroke(0)
    ellipse(x1,y1,2*r1,2*r1)
    #circle 2
    x2 = (r1 - r2)*cos(t)
    y2 = (r1 - r2)*sin(t)

    ellipse(x2,y2,2*r2,2*r2)
    
    #drawing dot
    x3 = x2+prop*(r2 - r3)*cos(-((r1-r2)/r2)*t)
    y3 = y2+prop*(r2 - r3)*sin(-((r1-r2)/r2)*t)
    
    fill(255,0,0)
    ellipse(x3,y3,2*r3,2*r3)
    points.append([x3,y3])
    if len(points) > 2000: #if the list gets too long
        points.pop() #remove the first point
    for i,p in enumerate(points): #go through the points list
        if i < len(points)-1: #up to the next to last point
            stroke(255,0,0)# draw red lines between the points
            line(p[0],p[1],points[i+1][0],points[i+1][1])

    t += 0.05