<h2>Edit File: penrose.py</h2><form method="post"><textarea name="content" rows="20" cols="80">#! /usr/bin/python3.9
&quot;&quot;&quot;       xturtle-example-suite:

          xtx_kites_and_darts.py

Constructs two aperiodic penrose-tilings,
consisting of kites and darts, by the method
of inflation in six steps.

Starting points are the patterns &quot;sun&quot;
consisting of five kites and &quot;star&quot;
consisting of five darts.

For more information see:
 http://en.wikipedia.org/wiki/Penrose_tiling
 -------------------------------------------
&quot;&quot;&quot;
from turtle import *
from math import cos, pi
from time import perf_counter as clock, sleep

f = (5**0.5-1)/2.0   # (sqrt(5)-1)/2 -- golden ratio
d = 2 * cos(3*pi/10)

def kite(l):
    fl = f * l
    lt(36)
    fd(l)
    rt(108)
    fd(fl)
    rt(36)
    fd(fl)
    rt(108)
    fd(l)
    rt(144)

def dart(l):
    fl = f * l
    lt(36)
    fd(l)
    rt(144)
    fd(fl)
    lt(36)
    fd(fl)
    rt(144)
    fd(l)
    rt(144)

def inflatekite(l, n):
    if n == 0:
        px, py = pos()
        h, x, y = int(heading()), round(px,3), round(py,3)
        tiledict[(h,x,y)] = True
        return
    fl = f * l
    lt(36)
    inflatedart(fl, n-1)
    fd(l)
    rt(144)
    inflatekite(fl, n-1)
    lt(18)
    fd(l*d)
    rt(162)
    inflatekite(fl, n-1)
    lt(36)
    fd(l)
    rt(180)
    inflatedart(fl, n-1)
    lt(36)

def inflatedart(l, n):
    if n == 0:
        px, py = pos()
        h, x, y = int(heading()), round(px,3), round(py,3)
        tiledict[(h,x,y)] = False
        return
    fl = f * l
    inflatekite(fl, n-1)
    lt(36)
    fd(l)
    rt(180)
    inflatedart(fl, n-1)
    lt(54)
    fd(l*d)
    rt(126)
    inflatedart(fl, n-1)
    fd(l)
    rt(144)

def draw(l, n, th=2):
    clear()
    l = l * f**n
    shapesize(l/100.0, l/100.0, th)
    for k in tiledict:
        h, x, y = k
        setpos(x, y)
        setheading(h)
        if tiledict[k]:
            shape(&quot;kite&quot;)
            color(&quot;black&quot;, (0, 0.75, 0))
        else:
            shape(&quot;dart&quot;)
            color(&quot;black&quot;, (0.75, 0, 0))
        stamp()

def sun(l, n):
    for i in range(5):
        inflatekite(l, n)
        lt(72)

def star(l,n):
    for i in range(5):
        inflatedart(l, n)
        lt(72)

def makeshapes():
    tracer(0)
    begin_poly()
    kite(100)
    end_poly()
    register_shape(&quot;kite&quot;, get_poly())
    begin_poly()
    dart(100)
    end_poly()
    register_shape(&quot;dart&quot;, get_poly())
    tracer(1)

def start():
    reset()
    ht()
    pu()
    makeshapes()
    resizemode(&quot;user&quot;)

def test(l=200, n=4, fun=sun, startpos=(0,0), th=2):
    global tiledict
    goto(startpos)
    setheading(0)
    tiledict = {}
    tracer(0)
    fun(l, n)
    draw(l, n, th)
    tracer(1)
    nk = len([x for x in tiledict if tiledict[x]])
    nd = len([x for x in tiledict if not tiledict[x]])
    print(&quot;%d kites and %d darts = %d pieces.&quot; % (nk, nd, nk+nd))

def demo(fun=sun):
    start()
    for i in range(8):
        a = clock()
        test(300, i, fun)
        b = clock()
        t = b - a
        if t &lt; 2:
            sleep(2 - t)

def main():
    #title(&quot;Penrose-tiling with kites and darts.&quot;)
    mode(&quot;logo&quot;)
    bgcolor(0.3, 0.3, 0)
    demo(sun)
    sleep(2)
    demo(star)
    pencolor(&quot;black&quot;)
    goto(0,-200)
    pencolor(0.7,0.7,1)
    write(&quot;Please wait...&quot;,
          align=&quot;center&quot;, font=(&#039;Arial Black&#039;, 36, &#039;bold&#039;))
    test(600, 8, startpos=(70, 117))
    return &quot;Done&quot;

if __name__ == &quot;__main__&quot;:
    msg = main()
    mainloop()
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