from __future__ import division, print_function
from visual import *
from time import sleep
# use "subprocess" instead of "thread" on python 3
from thread import start_new_thread
from random import *

def fall_ball(gravity, color, pos=(0, 5, 0)):
    our_ball = sphere(pos=pos, color=color)
    our_ball.pos = pos
    v_ball = 0
    
    while True:
        while our_ball.pos[1] > -5:
            sleep(0.02)
            our_ball.pos[1] -= v_ball
            v_ball += gravity
        
        v_ball = -v_ball
        our_ball.pos[1] -= v_ball

display(background=(1, 1, 1))

box(pos=(0, -5, 0), height=1, length=40, width=40)

# Constant speed!  Physics doesn't recommend that
#for height in range(500, -500, -1):
#    sleep(.002)
#    our_ball.pos = (0, height/100, 0)

for bnum in range(3000):
    sleep(random())
    start_new_thread(fall_ball, (0.01 + random()/100, (random(), random(), random()), ((0.5-random())*30, 5, (0.5-random())*30)))
    if bnum%100 == 0:
       print(bnum)
fall_ball(0.012, (1, 0, 0))