def check_aliens_bottom(ai_settings, stats, screen, ship, bullets, aliens):
"""检查是否有外星人到达了屏幕底端"""
screen_rect = screen.get_rect()
for alien in aliens.sprites():
if alien.rect.bottom >= screen_rect.bottom:
ship_hit(ai_settings, stats, screen, ship, bullets, aliens)
break
def check_aliens_bottom(ai_settings, stats, screen, ship, aliens, bullets):
screen_rect = screen.get_rect()
for alien in aliens.sprites():
if alien.rect.bottom >= screen_rect.bottom:
ship_hit(ai_settings, stats, screen, ship, aliens, bullets)
break
def change_fleet_direction(ai_settings, aliens):
for alien in aliens.sprites():
alien.rect.y += ai_settings.fleet_drop_speed
ai_settings.fleet_drop_direction *= -1
def check_fleet_edges(ai_settings, aliens):
for alien in aliens.sprites():
if alien.check_edges():
change_fleet_direction(ai_settings, aliens)
break
def change_fleet_direction(ai_settings, aliens):
"""将外星人向下移动，并改变运动方向"""
for alien in aliens.sprites():
alien.rect.y += ai_settings.fleet_drop_speed
ai_settings.fleet_direction *= -1