Cannonball in Visual Python

Just a very basic example of projectile motion in Visual Python. The cannon fires when the mouse is clicked in the window.

from visual import *

# Constants
g = 9.80            # (m/s^2)
v_0x = 5            # Initial speed in x-direction
v_0y = 50           # Initial speed in y-direction

# Set the display
scene = display(title='Cannonball',
                x=0, y=0, width=700, height=700,
                center=(0, 30, 0))

# Draw the cannon
outer = shapes.circle(pos=(0, 0), radius=1.2)
inner = shapes.circle(pos=(0, 0), radius=1)
location = [(0, 0, 0), (0.5, 5, 0)]
cannon = extrusion(pos=location, shape=outer-inner, color=color.green)


def position(t):
    """
    Move the cannonball according to the equations of projectile motion.
    """
    x = v_0x*t
    y = v_0y * t - 0.5 * g * t ** 2
    ball.pos = (x, y, 0)


# Shoot cannon when mouse is clicked and increment time
while True:
    rate(1000)
    if scene.mouse.clicked:
        m = scene.mouse.getclick()
        ball = sphere(pos=(0, 0, 0), radius=1, color=color.yellow, make_trail=True)
        i = 0
        flag = True
        while flag:
            rate(1000)
            position(i)
            i += 0.01
            if ball.pos[1] < 0:  # Stop before ball goes through the floor
                flag = False