目录
def show_score(self):
"""在屏幕上显示当前得分和最高得分"""
self.screen.blit(self.score_image, self.score_rect)
self.screen.blit(self.high_score_image, self.high_score_rect) def check_bullet_alien_collisions(ai_settings, screen, stats, sb, ship,
aliens, bullets):
--snip--
if collisions:
for aliens in collisions.values():
stats.score += ai_settings.alien_points * len(aliens)
sb.prep_score()
check_high_score(stats, sb)
--snip-- 
14.3.8 显示等级
def reset_stats(self):
"""初始化随游戏进行可能变化的统计信息"""
self.ships_left = self.ai_settings.ship_limit
self.score = 0
self.level = 1 def __init__(self, ai_settings, screen, stats):
--snip--
# 准备包含得分的初始图像
self.prep_score()
self.prep_high_score()
self.prep_level() def prep_level(self):
"""将等级转换为渲染的图像"""
1 self.level_image = self.font.render(str(self.stats.level), True,
self.text_color, self.ai_settings.bg_color)
# 将等级放在得分下方
self.level_rect = self.level_image.get_rect()
2 self.level_rect.right = self.score_rect.right
3 self.level_rect.top = self.score_rect.bottom + 10 def show_score(self):
"""在屏幕上显示飞船和得分"""
self.screen.blit(self.score_image, self.score_rect)
self.screen.blit(self.high_score_image, self.high_score_rect)
self.screen.blit(self.level_image, self.level_rect)def check_bullet_alien_collisions(ai_settings, screen, stats, sb, ship,
aliens, bullets):
--snip--
if len(aliens) == 0:
# 如果整群外星人都被消灭，就提高一个等级
bullets.empty()
ai_settings.increase_speed()
# 提高等级
1 stats.level += 1
2 sb.prep_level()
create_fleet(ai_settings, screen, ship, aliens)def check_play_button(ai_settings, screen, stats, sb, play_button, ship,
aliens, bullets, mouse_x, mouse_y):
"""在玩家单击Play按钮时开始新游戏"""
button_clicked = play_button.rect.collidepoint(mouse_x, mouse_y)
if button_clicked and not stats.game_active:
--snip--
# 重置游戏统计信息
stats.reset_stats()
stats.game_active = True
# 重置记分牌图像
1 sb.prep_score()
sb.prep_high_score()
sb.prep_level()
# 清空外星人列表和子弹列表
aliens.empty()
bullets.empty()
--snip-- def check_events(ai_settings, screen, stats, sb, play_button, ship, aliens,
bullets):
"""响应按键和鼠标事件"""
for event in pygame.event.get():
if event.type == pygame.QUIT:
--snip--
elif event.type == pygame.MOUSEBUTTONDOWN:
mouse_x, mouse_y = pygame.mouse.get_pos()
1 check_play_button(ai_settings, screen, stats, sb, play_button,
ship, aliens, bullets, mouse_x, mouse_y) # 开始游戏主循环
while True:
gf.check_events(ai_settings, screen, stats, sb, play_button, ship,
aliens, bullets)
--snip--现在你可以知道升到多少级了，如图14-5所示。
注意
在一些经典游戏中，得分带标签，如Score、High Score和Level。我们没有显示这些标签， 因为开始玩这款游戏后，每个数字的含义将一目了然。要包含这些标签，只需在Scoreboard 中调用font.render()前，将它们添加到得分字符串中即可。
14.3.9 显示余下的飞船数
import pygame
from pygame.sprite import Sprite
1 class Ship(Sprite):
def __init__(self, ai_settings, screen):
"""初始化飞船，并设置其起始位置"""
2 super(Ship, self).__init__()
--snip-- import pygame.font
from pygame.sprite import Group
from ship import Ship
class Scoreboard():
"""报告得分信息的类"""
def __init__(self, ai_settings, screen, stats):
--snip--
self.prep_level()
self.prep_ships()
--snip-- def prep_ships(self):
"""显示还余下多少艘飞船"""
1 self.ships = Group()
2 for ship_number in range(self.stats.ships_left):
ship = Ship(self.ai_settings, self.screen)
3 ship.rect.x = 10 + ship_number * ship.rect.width
4 ship.rect.y = 10
5 self.ships.add(ship) def show_score(self):
--snip--
self.screen.blit(self.level_image, self.level_rect)
# 绘制飞船
self.ships.draw(self.screen)
