class Background():
def __init__(self, screen, settings, group):
self.max_stars = 250
self.star_speed = 2
self.stars = []
self.group = group
self.screen = screen
# galaxy sprite
self.galaxy_last_release = pygame.time.get_ticks()
self.galaxy_released = True
self.galaxy_period = 10000
self.galaxy_speedx = 0
self.galaxy_speedy = 3
self.galaxy = GameObject(group, self.galaxy_speedx, self.galaxy_speedy,
randrange(100, 539), -100)
self.galaxy.set_image("assets/objects/galaxy.png")
def init_bkg(self):
""" Create the starfield """
for i in range(self.max_stars):
# A star is represented as a list with this format: [X,Y]
star = [
randrange(0,
self.screen.get_width() - 1),
randrange(0,
self.screen.get_height() - 1)
]
self.stars.append(star)
def update_stars(self):
""" Move and draw the stars in the given screen """
for star in self.stars:
star[1] += self.star_speed
# If the star hit the bottom border then we reposition
# it in the top of the screen with a random X coordinate.
if star[1] >= self.screen.get_height():
star[1] = 0
star[0] = randrange(0, 639)
def update_galaxy(self):
now = pygame.time.get_ticks()
if self.galaxy_released:
if now - self.galaxy_last_release > self.galaxy_period:
self.galaxy.set_y(-100)
self.galaxy.set_x(randrange(0, 639))
self.galaxy.set_speed_y(randrange(1, 3))
self.group.add(self.galaxy)
self.galaxy_released = False
self.galaxy_last_release = now
else:
if self.galaxy.get_y() >= self.screen.get_height():
self.galaxy_last_release = now
self.galaxy_released = True
self.galaxy.kill()
def update(self):
self.update_stars()
self.update_galaxy()
def draw(self):
for star in self.stars:
self.screen.set_at(star, (255, 255, 255))
