jpayne@68: """      turtle-example-suite:
jpayne@68: 
jpayne@68:           tdemo_wikipedia3.py
jpayne@68: 
jpayne@68: This example is
jpayne@68: inspired by the Wikipedia article on turtle
jpayne@68: graphics. (See example wikipedia1 for URLs)
jpayne@68: 
jpayne@68: First we create (ne-1) (i.e. 35 in this
jpayne@68: example) copies of our first turtle p.
jpayne@68: Then we let them perform their steps in
jpayne@68: parallel.
jpayne@68: 
jpayne@68: Followed by a complete undo().
jpayne@68: """
jpayne@68: from turtle import Screen, Turtle, mainloop
jpayne@68: from time import perf_counter as clock, sleep
jpayne@68: 
jpayne@68: def mn_eck(p, ne,sz):
jpayne@68:     turtlelist = [p]
jpayne@68:     #create ne-1 additional turtles
jpayne@68:     for i in range(1,ne):
jpayne@68:         q = p.clone()
jpayne@68:         q.rt(360.0/ne)
jpayne@68:         turtlelist.append(q)
jpayne@68:         p = q
jpayne@68:     for i in range(ne):
jpayne@68:         c = abs(ne/2.0-i)/(ne*.7)
jpayne@68:         # let those ne turtles make a step
jpayne@68:         # in parallel:
jpayne@68:         for t in turtlelist:
jpayne@68:             t.rt(360./ne)
jpayne@68:             t.pencolor(1-c,0,c)
jpayne@68:             t.fd(sz)
jpayne@68: 
jpayne@68: def main():
jpayne@68:     s = Screen()
jpayne@68:     s.bgcolor("black")
jpayne@68:     p=Turtle()
jpayne@68:     p.speed(0)
jpayne@68:     p.hideturtle()
jpayne@68:     p.pencolor("red")
jpayne@68:     p.pensize(3)
jpayne@68: 
jpayne@68:     s.tracer(36,0)
jpayne@68: 
jpayne@68:     at = clock()
jpayne@68:     mn_eck(p, 36, 19)
jpayne@68:     et = clock()
jpayne@68:     z1 = et-at
jpayne@68: 
jpayne@68:     sleep(1)
jpayne@68: 
jpayne@68:     at = clock()
jpayne@68:     while any(t.undobufferentries() for t in s.turtles()):
jpayne@68:         for t in s.turtles():
jpayne@68:             t.undo()
jpayne@68:     et = clock()
jpayne@68:     return "runtime: %.3f sec" % (z1+et-at)
jpayne@68: 
jpayne@68: 
jpayne@68: if __name__ == '__main__':
jpayne@68:     msg = main()
jpayne@68:     print(msg)
jpayne@68:     mainloop()