@Python编程从入门到实践 Python项目练习
十一、显示游戏得分及最高分
创建新类Scoreboard，用以显示得分和最高分。
# scoreboard.py
import pygame.font
class Scoreboard():
"""显示得分信息的类"""
def __init__(self, ai_settings, screen, stats):
"""初始化显示得分涉及的属性"""
self.screen = screen
self.screen_rect = screen.get_rect()
self.ai_settings = ai_settings
self.stats = stats
# 显示得分信息时使用的字体设置
self.text_color = (30, 30, 30)
self.font = pygame.font.SysFont(None, 48)
# 准备初始得分图像
self.prep_score()
# 准备最高得分
self.prep_high_score()
def prep_score(self):
"""将得分转换为一幅渲染的图像"""
rounded_score = int(round(self.stats.score, -1))
score_str = "{:,}".format(rounded_score)
self.score_image = self.font.render(score_str, True, self.text_color,
self.ai_settings.bg_color)
# 将得分放在屏幕右上角
self.score_rect = self.score_image.get_rect()
self.score_rect.right = self.screen_rect.right - 20
self.score_rect.top = 10
def prep_high_score(self):
"""将最高得分转为一幅渲染都图像"""
# 将得分圆整
high_score = int(round(self.stats.high_score, -1))
high_score_str = "{:,}".format(high_score)
self.high_score_image = self.font.render(high_score_str, True, self.text_color,
self.ai_settings.bg_color)
# 将得分放在屏幕顶部中央
self.high_score_rect = self.score_image.get_rect()
self.high_score_rect.centerx = self.screen_rect.centerx
self.high_score_rect.top = 10
def show_score(self):
"""在屏幕上显示得分"""
self.screen.blit(self.score_image, self.score_rect)
self.screen.blit(self.high_score_image, self.high_score_rect)
在game_stats中添加score属性，为每次重新开始都可以重置分数。
# game_stats.py
# def __init__(self, ai_settings):
# """初始化统计信息"""
# self.ai_settings = ai_settings
# self.reset_stats()
# self.game_active = False
# 在任何情况下都不应该重置最高分
self.high_score = 0
# def reset_stats(self):
# """初始化在游戏运行期间可能变化的统计信息"""
# self.ships_left = self.ai_settings.ship_limit
self.score = 0
在alien_invasion.py 中创建一个Scoreboard实例，并通过update_screen()函数在每次消灭乘客后更新分数。
# alien_inavsion.py
from scoreboard import Scoreboard
# --snip--
# 创建记分牌
sb = Scoreboard(ai_settings, screen, stats)
#while True：
# --snip--
gf.update_bullet_group(ai_settings, screen, stats, sb, ship, passenger_group, bullet_group)
# 每次循环重绘窗口并更新屏幕
gf.update_screen(ai_settings, screen, stats, sb, ship, passenger_group, bullet_group, play_button)
# --snip--
在settings.py中设定外星人的分数，并根据游戏难度的提高，提高外星人的分值
# settings.py
# 乘客点数的提高速度
self.score_scale = 1.5
# def initialize_dynamic_settings(self):
# """初始化随游戏进行而变化的动态设置"""
# 记分
self.passenger_points = 50
# def increase_speed(self):
# """提高速度的设置，同时提高乘客的分数"""
self.passenger_points = int(self.passenger_points * self.score_scale)
发生碰撞即遍历字典collisions中的一个键，确保每个子弹击中的乘客都有分数
# game_functions.py
def check_bullet_passenger_collisions(ai_settings, screen, stats, sb, ship, passenger_group, bullet_group):
# # 检查是否有子弹击中了乘客
# # 如果是这样，就删除相应的子弹和乘客
# # groupcollide（）返回字典，实参为True即删除发生碰撞的子弹或外星人
# collisions = pygame.sprite.groupcollide(bullet_group, passenger_group, False, True)
# if collisions:
for passenger_group in collisions.values():
stats.score += ai_settings.passenger_points * len(passenger_group)
sb.prep_score()
check_high_score(stats, sb)
def check_high_score(stats, sb):
"""检查是否诞生了新的最高分"""
if stats.score > stats.high_score:
stats.high_score = stats.score
sb.prep_high_score()
十二、显示飞机数量
首先，让Ship类继承Sprite，以便创建飞船编组。
# ship.py
from pygame.sprite import Sprite
#class Ship(Sprite):
# def __init__(self, ai_settings, screen):
# """初始化飞船并设置其初始位置"""
super(Ship, self).__init__()
def blitme_s(self):
"""在绘制剩余飞机数量"""
self.image = pygame.transform.scale(self.image, (37, 34))
self.screen.blit(self.image, self.rect)
修改scoreboard.py,创建一个可供显示的飞船编组,并绘制。
from pygame.sprite import Group
from ship import Ship
# 准备船的图像
self.prep_ships()
def prep_ships(self):
"""显示还余下多少艘飞船"""
self.ships = Group()
for ship_number in range(self.stats.ships_left):
ship = Ship(self.ai_settings, self.screen)
ship.rect.x = 10 + ship_number * ship.rect.width / 2
ship.rect.y = 10
self.ships.add(ship)
# def show_score(self):
# """在屏幕上显示得分"""
# self.screen.blit(self.score_image, self.score_rect)
# self.screen.blit(self.high_score_image, self.high_score_rect)
for ship in self.ships:
ship.blitme_s()
修改game_functions.py,确保游戏开始时显示飞船图像，在撞击之后损失一艘飞船图像。
# game_functions.py
def check_play_button(ai_settings, screen, stats, sb, play_button, ship,
passenger_group, bullet_group, mouse_x, mouse_y):
# """在玩家单击Play按钮时开始游戏"""
# 重置记分牌图像
sb.prep_score()
sb.prep_high_score()
sb.prep_ships()
def ship_hit(ai_settings, stats, sb, screen, ship, passenger_group, bullet_group):
# """响应被乘客撞到的飞船"""
# if stats.ships_left > 0:
# # 讲ship_left减一
# stats.ships_left -= 1
# 更新记分牌
sb.prep_ships()
注意修改alien_invasion.py中函数参数与game_functions.py中保持一下。
效果图
