def item_effect(event,ai_settings,screen,stats,aliens,ship_bullets,items):
if event.key == pygame.K_1 and stats.item_1 - len(ai_settings.timekeep[1]) > 0:
ai_settings.ship_bullet_width *= 8 # 飞船子弹宽度乘以 8
ai_settings.timekeep[1].append((time()))
elif event.key == pygame.K_2 and stats.item_2 - len(ai_settings.timekeep[2]) > 0:
ai_settings.floating_drop_speed /= 2 # 外星人下降速度除以 2
ai_settings.timekeep[2].append((time()))
elif event.key == pygame.K_3 and stats.item_3 - len(ai_settings.timekeep[3]) > 0:
ai_settings.energy_bullet = False # 普通子弹升级为高能子弹
ai_settings.timekeep[3].append((time()))
elif event.key == pygame.K_4 and stats.item_4 - len(ai_settings.timekeep[4]) > 0:
stats.killed_number += len(aliens.sprites())
stats.score += len(aliens.sprites()) * ai_settings.alien_points
stats.item_4 -= 1
aliens.empty()
ship_bullets.empty() # 清除屏幕上所有外星人
#refactor 两个if单独定义函数
if stats.killed_number // ai_settings.award_base > Item.count:
item = Item(ai_settings,screen)
item.caculate_number()
items.add(item)
if stats.killed_number // ai_settings.level_base > stats.level:
if stats.level < 20:
ai_settings.increase_speed()
stats.level += 1
elif event.key == pygame.K_5 and stats.item_5 - len(ai_settings.timekeep[5]) > 0:
ai_settings.effect_time *= 2
ai_settings.timekeep[5].append((time()))
elif event.key == pygame.K_6 and stats.item_6 - len(ai_settings.timekeep[6]) > 0:
ai_settings.timekeep[6].append(time())
def check_bullet_alien_collisions(ai_settings,screen,stats,ship,aliens,ship_bullets,items):
'''响应子弹与外星人的碰撞'''
# 检查是否有子弹击中了外星人，如果是，就删除相应的子弹和外星人
collisions = pygame.sprite.groupcollide(ship_bullets,aliens,ai_settings.energy_bullet,True)
# 计分
if collisions:
for aliens_hit in collisions.values():
stats.killed_number += len(aliens_hit)
stats.bullet_killed_number += len(aliens_hit)
stats.score += ai_settings.alien_points * len(aliens_hit)
#refactor 两个if单独定义函数
if stats.killed_number // ai_settings.award_base > Item.count:
item = Item(ai_settings,screen)
item.caculate_number()
items.add(item)
if stats.killed_number // ai_settings.level_base > stats.level:
if stats.level < 20:
ai_settings.increase_speed()
stats.level += 1