""" turtle-example-suite:
tdemo_round_dance.py
(Needs version 1.1 of the turtle module that
comes with Python 3.1)
Dancing turtles have a compound shape
consisting of a series of triangles of
decreasing size.
Turtles march along a circle while rotating
pairwise in opposite direction, with one
exception. Does that breaking of symmetry
enhance the attractiveness of the example?
Press any key to stop the animation.
Technically: demonstrates use of compound
shapes, transformation of shapes as well as
cloning turtles. The animation is
controlled through update().
"""
from turtle import *
def stop():
global running
running = False
def main():
global running
clearscreen()
bgcolor("gray10")
tracer(False)
shape("triangle")
f = 0.793402
phi = 9.064678
s = 5
c = 1
# create compound shape
sh = Shape("compound")
for i in range(10):
shapesize(s)
p =get_shapepoly()
s *= f
c *= f
tilt(-phi)
sh.addcomponent(p, (c, 0.25, 1-c), "black")
register_shape("multitri", sh)
# create dancers
shapesize(1)
shape("multitri")
pu()
setpos(0, -200)
dancers = []
for i in range(180):
fd(7)
tilt(-4)
lt(2)
update()
if i % 12 == 0:
dancers.append(clone())
home()
# dance
running = True
onkeypress(stop)
listen()
cs = 1
while running:
ta = -4
for dancer in dancers:
dancer.fd(7)
dancer.lt(2)
dancer.tilt(ta)
ta = -4 if ta > 0 else 2
if cs < 180:
right(4)
shapesize(cs)
cs *= 1.005
update()
return "DONE!"
if __name__=='__main__':
print(main())
mainloop()
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