游戏：外星人入侵（完整源码）

"""alien.py"""
"""外星人"""

import pygame
from pygame.sprite import Sprite

class Alien(Sprite):

    
    def __init__(self, ai_settings, screen):
        super(Alien, self).__init__()
        self.screen = screen
        self.ai_settings = ai_settings          #初始化外星人并设置起始位置

        self.image = pygame.image.load('images/alien.png')
        self.rect = self.image.get_rect()       #加载外星人图像

        self.rect.x = self.rect.width
        self.rect.y = self.rect.height          #外星人默认在屏幕左上角

        self.x = float(self.rect.x)             #保存外星人准确的位置

    def blitme(self):
        self.screen.blit(self.image, self.rect) #在指定位置位置外星人

    def check_edges(self):
        screen_rect = self.screen.get_rect()
        if self.rect.right >= screen_rect.right:
            return True                         #外星人达到右边缘返回T                    
        elif self.rect.left <= 0:
            return True                         #外星人达到左边缘返回T

    def update(self):
        self.x += (self.ai_settings.alien_speed_factor * 
                       self.ai_settings.fleet_direction)        
        self.rect.x = self.x                    #向左或向右移动外星人        

"""alien_invasion.py"""
"""游戏主程序"""

"""BUG"""
#游戏未开始状态，还能发射子弹
#等级无法提升和更新

import pygame
from pygame.sprite import Group
from settings import Settings
from game_stats import GameStats
from scoreboard import Scoreboard
from button import Button
from ship import Ship
import game_function as gf

def run_game():
    pygame.init()#初始化游戏
    ai_settings = Settings()
    screen = pygame.display.set_mode(
        (ai_settings.screen_width, ai_settings.screen_height))#创建游戏窗口
    pygame.display.set_caption("Alien Invasion")#游戏标题

    #创建开始按钮
    play_button = Button(ai_settings, screen, "Play")
    
    #游戏数据统计
    stats = GameStats(ai_settings)

    #创建记分牌
    sb = Scoreboard(ai_settings, screen, stats)

    #创建一艘飞船
    ship = Ship(ai_settings, screen)

    #存储子弹的编组
    bullets = Group()                                   
    aliens = Group()

    gf.create_fleet(ai_settings, screen, ship, aliens) #创建外星人群

    #主循环
    while True:
        gf.check_events(ai_settings, screen, stats, sb, play_button, ship, aliens, bullets)#获取键盘动作
        if stats.game_active:
            ship.update()#刷新键盘动作
            gf.update_bullets(ai_settings, screen, stats, sb, ship, aliens, bullets)#刷新子弹的位置
            gf.update_aliens(ai_settings, screen, stats, sb, ship, aliens, bullets)#刷新外星人的位置
            
        gf.update_screen(ai_settings, screen, stats, sb, ship, aliens, bullets, play_button)#不断刷新屏幕        

run_game()

"""bullet.py"""
"""子弹"""

import pygame
from pygame.sprite import Sprite

class Bullet(Sprite):

    def __init__(self, ai_settings, screen, ship):
        super(Bullet, self).__init__()
        self.screen = screen                  #在飞船位置创建一个子弹对象

        self.rect = pygame.Rect(0, 0, ai_settings.bullet_width,
                                ai_settings.bullet_height)
        self.rect.centerx = ship.rect.centerx
        self.rect.top = ship.rect.top         #创建一个子弹矩形

        self.y = float(self.rect.y)           #子弹的位置

        self.color = ai_settings.bullet_color
        self.speed_factor = ai_settings.bullet_speed_factor

    def update(self):
        self.y -= self.speed_factor #更新子弹位置的小数值
        self.rect.y = self.y        #更新子弹的位置

    def draw_bullet(self):
        pygame.draw.rect(self.screen, self.color, self.rect)

"""button.py"""
"""开始按钮"""

import pygame.font

class Button():

    def __init__(self, ai_settings, screen, msg):
        #初始化按钮
        self.screen = screen
        self.screen_rect = screen.get_rect()    

        #设置按钮
        self.width, self.height = 200, 50
        self.button_color = (0, 255, 0)
        self.text_color = (255, 255, 255)
        self.font = pygame.font.SysFont(None, 48)

        #创建按钮的rect对象，并居中
        self.rect = pygame.Rect(0, 0, self.width, self.height)
        self.rect.center = self.screen_rect.center

        #仅创建一次按钮标签
        self.prep_msg(msg)

    def prep_msg(self, msg):
        #将msg渲染成图像，并在按钮上居中
        self.msg_image = self.font.render(msg, True, self.text_color,
                                          self.button_color)
        self.msg_image_rect = self.msg_image.get_rect()
        self.msg_image_rect.center = self.rect.center

    def draw_button(self):
        #显示在屏幕上
        self.screen.fill(self.button_color, self.rect)
        self.screen.blit(self.msg_image, self.msg_image_rect)        

"""game_function.py"""
"""核心函数"""

import sys
from time import sleep
import pygame
from bullet import Bullet
from alien import Alien

#按下键盘
def check_keydown_events(event, ai_settings, screen, ship, bullets):
    if event.key == pygame.K_RIGHT:
        ship.moving_right = True
    elif event.key == pygame.K_LEFT:
        ship.moving_left = True
    elif event.key == pygame.K_UP:
        ship.moving_up = True
    elif event.key == pygame.K_DOWN:
        ship.moving_down = True
    elif event.key == pygame.K_SPACE:
        fire_bullet(ai_settings, screen, ship, bullets)
    elif event.key == pygame.K_q:
        sys.exit()

def fire_bullet(ai_settings, screen, ship, bullets):
    if len(bullets) < ai_settings.bullets_allowed:  #限制显示子弹的个数
        new_bullet = Bullet(ai_settings, screen, ship)
        bullets.add(new_bullet)

#弹起键盘
def check_keyup_events(event, ship):
    if event.key == pygame.K_RIGHT:
        ship.moving_right = False
    elif event.key == pygame.K_LEFT:
        ship.moving_left = False
    elif event.key == pygame.K_UP:
        ship.moving_up = False
    elif event.key == pygame.K_DOWN:
        ship.moving_down = False

#获取键盘动作
def check_events(ai_settings, screen, stats, sb, play_button, ship, aliens, bullets):
    for event in pygame.event.get():
        if event.type == pygame.QUIT:#QUIT则退出游戏
            sys.exit()
        elif event.type == pygame.KEYDOWN:
            check_keydown_events(event, ai_settings, screen, ship, bullets)
        elif event.type == pygame.KEYUP:
            check_keyup_events(event, ship)
        elif event.type == pygame.MOUSEBUTTONDOWN:
            mouse_x, mouse_y = pygame.mouse.get_pos()
            check_play_button(ai_settings, screen, stats, sb, play_button, ship,
                              aliens, bullets, mouse_x, mouse_y)
            
#点击按钮才会触发游戏继续
def check_play_button(ai_settings, screen, stats, sb, play_button, ship, aliens,
                      bullets, mouse_x, mouse_y):
    button_clicked = play_button.rect.collidepoint(mouse_x, mouse_y)
    if button_clicked and not stats.game_active:
        #重置游戏设置
        ai_settings.initialize_dynamic_settings()
        #隐藏光标
        pygame.mouse.set_visible(False)
        #重置游戏统计信息
        stats.reset_stats()
        stats.game_active = True

        #重置记分牌图像
        sb.prep_score()
        sb.prep_high_score()
        sb.prep_level()
        sb.prep_ships()

        #清空外星人和子弹列表
        aliens.empty()
        bullets.empty()

        #创建一群新的外星人，并让飞船居中
        create_fleet(ai_settings, screen, ship, aliens)
        ship.center_ship()

#刷新屏幕
def update_screen(ai_settings, screen, stats, sb, ship, aliens, bullets, play_button):
    screen.fill(ai_settings.bg_color)   #不断刷新屏幕
    for bullet in bullets.sprites():
        bullet.draw_bullet()
        
    ship.blitme()                       #不断刷新飞船
    aliens.draw(screen)                 #不断刷新外星人
    sb.show_score()                     #显示得分
    if not stats.game_active:
        play_button.draw_button()       #游戏处于非活跃状态，就显示PLAY按钮
    
    pygame.display.flip()               #显示最新屏幕

#刷新子弹
def update_bullets(ai_settings, screen, stats, sb, ship, aliens, bullets):
    bullets.update()                    #更新子弹的位置

    for bullet in bullets.copy():       
        if bullet.rect.bottom <= 0:
            bullets.remove(bullet)      #删除已消失的子弹
            
    #如果外星人被消灭光，则新建一批外星人
    if len(aliens) == 0:
        bullets.empty()
        create_fleet(ai_settings, screen, ship, aliens)

    check_bullet_alien_collisions(ai_settings, screen, stats, sb, ship, aliens, bullets)

#检查是否诞生最高分
def check_high_score(stats, sb):
    if stats.score > stats.high_score:
        stats.high_score = stats.score
        sb.prep_high_score()
    

#响应子弹和外星人的碰撞
def check_bullet_alien_collisions(ai_settings, screen, stats, sb, ship, aliens, bullets):
    collisions = pygame.sprite.groupcollide(bullets, aliens, True, True)    #子弹碰到外星人时，都会消失
    if collisions:
        for aliens in collisions.values():
            stats.score += ai_settings.alien_points * len(aliens)
            sb.prep_score()
        check_high_score(stats, sb)
            
    if len(aliens) == 0:
        #删除现有子弹、加快速度、创建一群新的外星人
        bullets.empty()
        ai_settings.increase_speed()

        #提高等级
        stats.level += 1
        sb.prep_level()
        
        create_fleet(ai_settings, screen, ship, aliens)

#每行显示外星人的个数
def get_number_aliens_x(ai_settings, alien_width):
    available_space_x = ai_settings.screen_width - 2 * alien_width
    number_aliens_x = int(available_space_x / (2 * alien_width))
    return number_aliens_x

#计算可容纳多少行外星人
def get_number_rows(ai_settings, ship_height, alien_height):
    available_space_y = (ai_settings.screen_height -
                         (3 * alien_height) - ship_height)
    number_rows = int(available_space_y / (2 * alien_height))
    return number_rows

#创建一个外星人，放在当前行
def create_alien(ai_settings, screen, aliens, alien_number, row_number):
    alien = Alien(ai_settings, screen)
    alien_width = alien.rect.width
    alien.x = alien_width + 2 * alien_width * alien_number
    alien.rect.x = alien.x
    alien.rect.y = alien.rect.height + 2 * alien.rect.height * row_number
    aliens.add(alien)

#创建外星人群
def create_fleet(ai_settings, screen, ship, aliens):
    alien = Alien(ai_settings, screen)
    number_aliens_x = get_number_aliens_x(ai_settings, alien.rect.width)
    number_rows = get_number_rows(ai_settings, ship.rect.height,
                                  alien.rect.height)

    for row_number in range(number_rows):
        for alien_number in range(number_aliens_x):
            create_alien(ai_settings, screen, aliens, alien_number, row_number)

#外星人达到边缘时触发change_fleet_direction函数
def check_fleet_edges(ai_settings, aliens):
    for alien in aliens.sprites():
        if alien.check_edges():
            change_fleet_direction(ai_settings, aliens)
            break
        
#外星人下移，并改变它们的方向
def change_fleet_direction(ai_settings, aliens):
    for alien in aliens.sprites():
        alien.rect.y += ai_settings.fleet_drop_speed
    ai_settings.fleet_direction *= -1

#更新外星人的位置
def update_aliens(ai_settings, screen, stats, sb, ship, aliens, bullets):
    check_fleet_edges(ai_settings, aliens)
    aliens.update()
    if pygame.sprite.spritecollideany(ship, aliens):
       ship_hit(ai_settings, screen, stats, sb, ship, aliens, bullets)

    check_aliens_bottom(ai_settings, screen, stats, sb, ship, aliens, bullets)

#响应外星人撞到飞船
def ship_hit(ai_settings, screen, stats, sb, ship, aliens, bullets):
    if stats.ships_left > 0:
        stats.ships_left -= 1   #ships_left减1

        #更新记分牌
        sb.prep_ships()

        aliens.empty()
        bullets.empty()         #清空外星人列表和子弹列表

        create_fleet(ai_settings, screen, ship, aliens)
        ship.center_ship()      #创建一群新的外星人

        sleep(0.5)              #暂停
    else:
        stats.game_active = False
        pygame.mouse.set_visible(True)

#检查外星人是否达到底部
def check_aliens_bottom(ai_settings, screen, stats, sb, ship, aliens, bullets):
    screen_rect = screen.get_rect()
    for alien in aliens.sprites():
        if alien.rect.bottom >= screen_rect.bottom:
            ship_hit(ai_settings, screen, stats, sb, ship, aliens, bullets)
            break

"""game_stats.py"""
"""游戏统计信息"""

class GameStats():

    def __init__(self, ai_settings):
        self.ai_settings = ai_settings
        self.reset_stats()
        
        self.game_active = False
        self.high_score = 0

    def reset_stats(self):
        self.ships_left = self.ai_settings.ship_limit
        self.score = 0
        self.level = 1
        

"""scoreboard.py"""
"""记分"""

import pygame.font
from pygame.sprite import Group
from ship import Ship

class Scoreboard():

    def __init__(self, ai_settings, screen, stats):
        #初始化记分相关属性
        self.screen = screen
        self.screen_rect = screen.get_rect()
        self.ai_settings = ai_settings
        self.stats = stats

        #记分数字显示效果
        self.text_color = (30, 30, 30)
        self.font = pygame.font.SysFont(None, 48)

        #初始得分图像
        self.prep_score()
        self.prep_high_score()
        self.prep_level()
        self.prep_ships()

    def prep_score(self):
        #将得分渲染为图像
        score_str = str(self.stats.score)
        self.score_image = self.font.render(score_str, True, self.text_color,
                                            self.ai_settings.bg_color)
        
        #将得分固定在右上角
        self.score_rect = self.score_image.get_rect()
        self.score_rect.right = self.screen_rect.right - 20
        self.score_rect.top = 20

    def prep_high_score(self):
        """将最高得分渲染为图像"""
        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)
        #将最高分放在屏幕顶部中央
        self.high_score_rect = self.high_score_image.get_rect()
        self.high_score_rect.centerx = self.screen_rect.centerx
        self.high_score_rect.top = self.score_rect.top
        

    def show_score(self):
        #在屏幕上显示得分和最高分
        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)

        #绘制飞船
        self.ships.draw(self.screen)

    def prep_level(self):
        """将等级渲染为图像"""
        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()
        self.level_rect.right = self.score_rect.right
        self.level_rect.top = self.score_rect.bottom + 10

    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
            ship.rect.y = 10
            self.ships.add(ship)

"""settings.py"""
"""初始设置"""

class Settings():

    def __init__(self):
        
        self.screen_width = 1200            #游戏窗口尺寸
        self.screen_height = 800
        
        self.bg_color = (230, 230, 230)     #游戏窗口背景色

        #飞船设置
        self.ship_limit = 3

        #子弹设置
        self.bullet_width = 5
        self.bullet_height = 15             #宽3、高15像素的矩形（子弹）
        self.bullet_color = 60, 60, 60
        self.bullets_allowed = 3
    
        #外星人设置
        #外星人下移的速度
        self.fleet_drop_speed = 10          
        #游戏速度
        self.speedup_scale = 1.1            
        #分值增加幅度
        self.score_scale = 1.5
        
        self.initialize_dynamic_settings()

    def initialize_dynamic_settings(self):
        #初始化随游戏进行而变化的设置
        self.ship_speed_factor = 1.5
        self.bullet_speed_factor = 3
        self.alien_speed_factor = 1
        #1表示右移、1表示左移
        self.fleet_direction = 1
        #记分基数
        self.alien_points = 50

    def increase_speed(self):
        #提高速度
        self.ship_speed_factor *= self.speedup_scale
        self.bullet_speed_factor *= self.speedup_scale
        self.alien_speed_factor *= self.speedup_scale

        self.alien_points = int(self.alien_points * self.score_scale)       

"""ship.py"""
"""飞船"""

import pygame
from pygame.sprite import Sprite

class Ship(Sprite):
    
    def __init__(self, ai_settings, screen):
        super(Ship, self).__init__()
        self.screen = screen
        self.ai_settings = ai_settings

        self.image = pygame.image.load('images/ship.png')   #载入飞船图像
        self.rect = self.image.get_rect()                   #获取飞船的surface属性
        self.screen_rect = screen.get_rect()                #获取游戏窗口的surface属性

        self.rect.centerx = self.screen_rect.centerx        #将飞船的中心位置等于窗口的中心
        self.rect.bottom = self.screen_rect.bottom          #将飞船的底部等于窗口的底部

        self.centerx = float(self.rect.centerx)              #在飞船的属性center中存储小数值
        self.centery = float(self.rect.centery) 

        self.moving_right = False                           #飞船的移动标志
        self.moving_left = False
        self.moving_up = False
        self.moving_down = False
        
    #飞船移动函数
    #rect对象的上下左右为top/bottom/left/right，而非up/down/left/right
    def update(self):
        if self.moving_right and self.rect.right < self.screen_rect.right:
            self.centerx += self.ai_settings.ship_speed_factor                #右移
        if self.moving_left and self.rect.left > 0:
            self.centerx -= self.ai_settings.ship_speed_factor                #左移
            
        if self.moving_up and self.rect.top > 0:
            self.centery -= self.ai_settings.ship_speed_factor                #上移
        if self.moving_down and self.rect.bottom < self.screen_rect.bottom:
            self.centery += self.ai_settings.ship_speed_factor                #下移

        #根据self.center更新rect对象
        self.rect.centerx = self.centerx
        self.rect.centery = self.centery
            
    def blitme(self):
        self.screen.blit(self.image, self.rect)

    def center_ship(self):
        self.center = self.screen_rect.centerx  #让飞船居中