'Simulates fireball bounce off ground'

def bounce_fireball(self, fireball):

    fireball.y_vel = (-8)
    if (fireball.direction == c.RIGHT):
        fireball.x_vel = 15
    else:
        fireball.x_vel = (-15)
    if (fireball in self.powerup_group):
        fireball.state = c.BOUNCING
