a bouncing ball, using a vector for movement

bounce.py

import sys, time, math
from pyglet.gl import *
from euclid import *

window = pyglet.window.Window(512,512)

quadric = gluNewQuadric()
ballPos = Vector2(256,256)
ballVel = Vector2(200,145)

@window.event
def on_draw():
    glClear(GL_COLOR_BUFFER_BIT)
    glPushMatrix()
    glTranslatef(ballPos[0], ballPos[1], 0)
    glColor3f(1,0,0)
    gluDisk(quadric, 0, 20, 32, 1)
    glPopMatrix()


def checkForBounce():
	if ballPos[0] > 512.0:
		ballVel[0] = -ballVel[0]
		ballPos[0] = 512.0 - (ballPos[0] - 512.0)
	elif ballPos[0] < 0.0:
		ballVel[0] = -ballVel[0]
		ballPos[0] = -ballPos[0]
	if ballPos[1] > 512.0:
		ballVel[1] = -ballVel[1]
		ballPos[1] = 512.0 - (ballPos[1] - 512.0)
	elif ballPos[1] < 0.0:
		ballVel[1] = -ballVel[1]
		ballPos[1] = -ballPos[1]

def update(dt):
    global ballPos, ballVel
    ballPos += ballVel * dt
    checkForBounce()

pyglet.clock.schedule_interval(update,1/60.0)
pyglet.app.run()