外星人入侵
这次小编上传一个游戏开发的项目,一方面是自己写上去能更好的熟悉这个项目,并且把自己的心得可以分享上面,另一方面,可以让更多的盆友看到,提高自我。
这个游戏项目使用的是pygame,这是一组强大而有趣的模块,可用于管理图形,动画乃至声音,让你能更轻松的开发复杂的游戏,通过使用pygame来处理在屏幕上绘制图像等任务,我们不用考虑多繁琐而艰难的编程工作,而是将重点放在程序上的高级逻辑上面。
第一步:规划项目
开发大型项目时候,做好规划再动手编写项目很重要,规划可以确保我们不偏离轨道,从而提高项目成功的可能性。
下面 来编写有关游戏《外星人入侵》的描述,可能其中没有涵盖所有的游戏细节,但是嗯那个让我们狠清晰的知道如何动手开发它
在游戏《外星人入侵》中,玩家控制着一艘最初出现在屏幕底部中央的飞船。玩家可以使用箭头键左右移动飞船,还可以使用空格键进行设计。游戏开始时,一群外星人出现在天空,他们在屏幕中向下移动。玩家的任务是射杀这些外星人。玩家将所有的外星人射击干净后,将出现一个新的外星人,他们的移动宿舍更快。只要有外星人撞到玩家的飞船或者到达屏幕底部,玩家就损失一所飞船。玩家损失三艘飞船后,游戏结束。
第二步:安装pygame
pygame项目托管在代码分享网址Bitbucket中,要在windows系统中安装pygame,则可以访问网站
https://bitbucket.org/pygame/pygame/downloads/
(在网址中查找合适的程序下载)
安装程序如下:
pip install pygame-1.9.3-cp36-cp36m-win_amd64.whl
第三步:开始游戏项目
首先得创建游戏界面,然后添加飞船图像,飞船添加上去,我们必须允许它可以左右移动,再添加射击子弹的功能。
然后创建外星人,让外星人移动,我们进行射击外星人,然后结束游戏。
最后我们得进行记分,提高等级等设置,急需完善游戏,这样一个游戏就设置完毕。
说起来简单,但是做起来难。这三部分,每部分都是一个整体,而且实现新功能时候,必须重构源代码,一不小心就出错,所以得格外注意。
具体的项目实施步骤,我就在这里不一一讲解了,主要把代码贴出来,让大家参考一下
这个是所有代码的目录:
首先是主程序 alien_invasion.py
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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 from alien import Alien import game_functions as gf def run_game(): # Initialize pygame, settings, and screen object. pygame.init() ai_settings = Settings() screen = pygame.display.set_mode( (ai_settings.screen_width, ai_settings.screen_height)) pygame.display.set_caption("Alien Invasion") #创建play按钮 play_button = Button(ai_settings,screen,"Play") #创建一个用于存储游戏统计信息的实例 stats = GameStats(ai_settings) sb = Scoreboard(ai_settings,screen,stats) # Set the background color. bg_color = (230, 230, 230) # Make a ship. ship = Ship(ai_settings, screen) # Make a group to store bullets in. bullets = Group() aliens = Group() #创建外星人群 gf.create_fleet(ai_settings,screen,ship,aliens) # Start the main loop for the game. while True: gf.check_events(ai_settings, screen, stats,sb,play_button,ship, aliens, bullets) if stats.game_active: ship.update() gf.update_bullets(ai_settings,screen,stats,sb,ship,aliens,bullets) gf.update_aliens(ai_settings,screen,stats,sb,ship,aliens,bullets) gf.update_screen(ai_settings, screen,stats, sb,ship,aliens, bullets,play_button) run_game()
然后是功能函数 game_function.py
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import sys from time import sleep import pygame from bullet import Bullet from alien import Alien import pygame def check_keydown_events(event, ai_settings, screen, ship, bullets): """Respond to keypresses.""" 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_SPACE: fire_bullet(ai_settings, screen, ship, bullets) def check_keyup_events(event, ship): """Respond to key releases.""" if event.key == pygame.K_RIGHT: ship.moving_right = False elif event.key == pygame.K_LEFT: ship.moving_left = False def check_events(ai_settings, screen, stats,sb, play_button,ship,aliens, bullets): """Respond to keypresses and mouse events.""" for event in pygame.event.get(): if event.type == pygame.QUIT: 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) def check_play_button(ai_settings,screen,stats,sb,play_button, ship,aliens,bullets,mouse_x,mouse_y): """玩家单击play按钮开始新游戏""" 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) if play_button.rect.collidepoint(mouse_x,mouse_y): #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() #清空外星人列表和子弹列表 aliens.empty() bullets.empty() #创建一群新的外星人,并让其居中 create_fleet(ai_settings,screen,ship,aliens) ship.center_ship() def fire_bullet(ai_settings, screen, ship, bullets): """Fire a bullet, if limit not reached yet.""" # Create a new bullet, add to bullets group. if len(bullets) < ai_settings.bullets_allowed: new_bullet = Bullet(ai_settings, screen, ship) bullets.add(new_bullet) def update_screen(ai_settings, screen, stats,sb,ship, aliens,bullets,play_button): """Update images on the screen, and flip to the new screen.""" # Redraw the screen, each pass through the loop. screen.fill(ai_settings.bg_color) # Redraw all bullets, behind ship and aliens. for bullet in bullets.sprites(): bullet.draw_bullet() ship.blitme() aliens.draw(screen) #显示得分 sb.show_score() #如果游戏处于非活跃状态,就绘制play按钮 if not stats.game_active: play_button.draw_button() # Make the most recently drawn screen visible. pygame.display.flip() def update_bullets(ai_settings,screen,stats,sb,ship,aliens,bullets): """Update position of bullets, and get rid of old bullets.""" # Update bullet positions. bullets.update() # Get rid of bullets that have disappeared. for bullet in bullets.copy(): if bullet.rect.bottom <= 0: bullets.remove(bullet) check_bullet_alien_collisions(ai_settings,screen,stats,sb,ship,aliens,bullets) def check_bullet_alien_collisions(ai_settings,screen,stats,sb,ship,aliens,bullets): #检查是否有子弹击中了外星人 #如果是这样样,就删除相应的额子弹和外星人 collisions = pygame.sprite.groupcollide(bullets,aliens,True,True) 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: # If the entire fleet is destroyed, start a new level. bullets.empty() ai_settings.increase_speed() #提高等级 stats.level +=1 sb.prep_level() create_fleet(ai_settings,screen,ship,aliens) def get_number_aliens_x(ai_settings,alien_width): """计算每行可容纳多少个外星人""" available_space_x = ai_settings.screen_width - 2 * alien_width number_aliens_x = int(available_space_x / (2 * alien_width)) return number_aliens_x def get_number_rows(ai_settings,ship_height,aliens_height): """计算屏幕可以容纳多少个外星人""" avaliable_space_y = (ai_settings.screen_height -(3*aliens_height)-ship_height) number_rows = int(avaliable_space_y /(2*aliens_height)) return number_rows def create_alien(ai_settings,screen,aliens,alien_number,row_number): """创建一个外星人并将其放在当前列""" 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) def create_fleet(ai_settings,screen,ship,aliens): """创建外星人群""" #创建一个外星人,并计算一行可以容纳多少个外星人,外星人间距为外星人的宽度 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) #创建外星人群 for row_number in range(number_rows): for alien_number in range(number_aliens_x): #创建一个外星人并将其加入当前行 create_alien(ai_settings,screen,aliens,alien_number,row_number) def check_fleet_edges(ai_settings,aliens): """有外星人到达边缘时候采取相应的措施""" for alien in aliens.sprites(): if alien.check_edges(): change_fleet_direction(ai_settings,aliens) break def change_fleet_direction(ai_settings,aliens): """将整群外星人下移,并改变他们的方向""" for alien in aliens.sprites(): alien.rect.y += ai_settings.fleet_drop_speed ai_settings.fleet_direction *= -1 def update_aliens(ai_settings,screen,stats,sb,ship,aliens,bullets): """检查是否有外星人位于屏幕边缘,更新外星人群中所有外星人的位置""" check_fleet_edges(ai_settings,aliens) aliens.update() #监测外星人和飞船之间的碰撞 if pygame.sprite.spritecollideany(ship,aliens): ship_hit(ai_settings,screen,stats,sb,ship,aliens,bullets) #检查是狗友外星人到达屏幕底部 check_aliens_bottom(ai_settings,screen,stats,sb,ship,aliens,bullets) def ship_hit(ai_settings,screen,stats,sb,ship,aliens,bullents): """响应被外星人撞到的飞船""" if stats.ships_left >0: # 将shios_left减1 stats.ships_left -=1 #更新记分牌 sb.prep_ships() else: stats.game_active = False #清空外星人列表和子弹列表 pygame.mouse.set_visible(True) aliens.empty() bullents.empty() #创建一群新的外星人 create_fleet(ai_settings,screen,ship,aliens) ship.center_ship() #暂停 sleep(3) def check_aliens_bottom(ai_settings,screen,stats,ship,sb,aliens,bullets): """检查是否有外星人到达了屏幕底部""" screen_rect = screen.get_rect() for alien in aliens.sprites(): if alien.rect.bottom >= screen_rect.bottom: #像飞船被撞到一样处理 ship_hit(ai_settings,stats,screen,ship,sb,aliens,bullets) break def check_high_score(stats,sb): """检查是否诞生了新的得分最高""" if stats.score > stats.high_score: stats.high_score = stats.score sb.prep_high_score()
下面是设置函数 settings
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class Settings(): """A class to store all settings for Alien Invasion.""" def __init__(self): """Initialize the game's settings.""" # Screen settings self.screen_width = 1100 self.screen_height = 700 self.bg_color = (230, 230, 230) # 飞船设置 #self.ship_speed_factor = 1.5 #self.bullet_speed_factor = 3 self.ship_limit = 3 # Bullet settings self.bullet_speed_factor = 3 self.bullet_width = 3 self.bullet_height = 25 self.bullet_color = 60, 60, 60 self.bullets_allowed = 2 #外星人设置 #self.alien_speed_factor = 1 self.fleet_drop_speed = 10 #fleet_direction为1表示向右移动,-1表示向左移动 self.fleet_direction = 1 #以什么样的速度加快游戏节奏 self.fleet_drop_speed = 10 #加快游戏节奏的速度 self.speedup_scale = 1.1 #外星人点数提高 self.score_scale = 1.5 self.initialize_dynamic_settings() def increase_speed(self): """提高速度设置""" 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) #print(self.alien_points) def initialize_dynamic_settings(self): """初始化岁游戏进行二变化的设置""" self.ship_speed_factor = 1.5 self.bullet_speed_factor = 3 self.alien_speed_factor = 3 # fleet_direction为1表示向右移动,-1表示向左移动 self.fleet_direction = 1 #积分 self.alien_points = 50
这个是我方飞机的设置函数ship.py
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import pygame from pygame.sprite import Sprite class Ship(Sprite): def __init__(self, ai_settings, screen): """Initialize the ship, and set its starting position.""" super(Ship,self).__init__() self.screen = screen self.ai_settings = ai_settings # Load the ship image, and get its rect. self.image = pygame.image.load('images/ship.bmp') self.rect = self.image.get_rect() self.screen_rect = screen.get_rect() # Start each new ship at the bottom center of the screen. self.rect.centerx = self.screen_rect.centerx self.rect.bottom = self.screen_rect.bottom # Store a decimal value for the ship's center. self.center = float(self.rect.centerx) # Movement flags. self.moving_right = False self.moving_left = False def update(self): """Update the ship's position, based on movement flags.""" # Update the ship's center value, not the rect. if self.moving_right and self.rect.right < self.screen_rect.right: self.center += self.ai_settings.ship_speed_factor if self.moving_left and self.rect.left > 0: self.center -= self.ai_settings.ship_speed_factor # Update rect object from self.center. self.rect.centerx = self.center def blitme(self): """Draw the ship at its current location.""" self.screen.blit(self.image, self.rect) def center_ship(self): """让飞船在屏幕上剧中""" self.center = self.screen_rect.centerx
这个是敌方飞机的设置函数alien.py
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import pygame from pygame.sprite import Sprite class Alien(Sprite): """表示单个外星人""" def __init__(self,ai_settings,screen): """初始化外星人并设置其起始位置""" super(Alien,self).__init__() self.screen = screen self.ai_settings = ai_settings #加载外星人图像,并设置rect属性 self.image = pygame.image.load('images/alien.bmp') self.rect = self.image.get_rect() #每个外星人最初都在屏幕右上角附近 self.rect.x = self.rect.width self.rect.y = self.rect.height #存储外星人的准确位置 self.x = float(self.rect.x) def check_edges(self): """如果外星人位于屏幕边缘,就返回True""" screen_rect = self.screen.get_rect() if self.rect.right >=screen_rect.right: return True elif self.rect.left <=0: return True def update(self): """向左或者向右移动外星人""" self.x += (self.ai_settings.fleet_direction * self.ai_settings.alien_speed_factor) self.rect.x = self.x def blitme(self): """在指定位置绘制外星人""" self.screen.blit(self.image,self.rect)
这个是子弹设置的函数bullet.py
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import pygame from pygame.sprite import Sprite class Bullet(Sprite): """A class to manage bullets fired from the ship""" def __init__(self, ai_settings, screen, ship): """Create a bullet object at the ship's current position.""" super(Bullet, self).__init__() self.screen = screen # Create a bullet rect at (0, 0) and then set correct position. 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 # Store the bullet's position as a decimal value. self.y = float(self.rect.y) self.color = ai_settings.bullet_color self.speed_factor = ai_settings.bullet_speed_factor def update(self): """Move the bullet up the screen.""" # Update the decimal position of the bullet. self.y -= self.speed_factor # Update the rect position. self.rect.y = self.y def draw_bullet(self): """Draw the bullet to the screen.""" pygame.draw.rect(self.screen, self.color, self.rect)
这个是按钮设置的函数button.py
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import pygame.font class Button(): def __init__(self,ai_settings,screen,msg): """初始化按钮的属性""" self.screen = screen self.screen_rect = screen.get_rect() #设置按钮的尺寸和其他属性 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,并使其剧中 self.rect = pygame.Rect(0,0,self.width,self.height) self.rect.center = self.screen_rect.center #按钮的标签只需要一次 self.prep_msg(msg) def prep_msg(self,msg): """将msg渲染为图像,并使其在按钮上居中""" 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): #绘制一个用颜色填充的按钮,再绘制文本 self.screen.fill(self.button_color,self.rect) self.screen.blit(self.msg_image,self.msg_image_rect)
这个是记分牌设置的函数scoreboard.py
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import pygame.font from pygame.sprite import Group from ship import Ship 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 #显示得分信息时候使用的字体设置 self.text_color = (30,30,30) self.font = pygame.font.SysFont(None,48) #准备初始得分图像 self.prep_score() self.prep_high_score() self.prep_level() self.prep_ships() #准备包含最高分和当前的分的图像 self.prep_score() self.prep_high_score() def prep_score(self): """将得分转化为一副渲染的图像""" 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 = 20 def prep_high_score(self): """将最高分转换为渲染的图像""" 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) # 将最高得分放在屏幕中央 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) #绘制飞船 self.ships.draw(self.screen) def prep_level(self): """将等级转化为渲染的图像""" self.level_image = self.font.render(str(self.stats.level),True, self.text_color,self.ai_settings.bg_color) #将等级放在得分下面 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): """显示还剩下多少搜飞船""" 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)
这个是跟踪游戏统计信息的类game_stats.py
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class GameStats(): """跟踪游戏的统计信息""" def __init__(self,ai_settings): """初始化统计信息""" self.ai_settings = ai_settings self.reset_stats() #游戏刚开始处于0活跃状态 self.game_active = False #在任何情况下都不应重置最高得分 self.high_score = 0 def reset_stats(self): """初始化在游戏与逆行期间可能变化的统计信息""" self.ships_left = self.ai_settings.ship_limit self.score = 0 self.level = 1
第四步:游戏结果展示
图一:开始界面图:
图二:游戏中的图
第五步:游戏总结
这个游戏做的比较仓促,还存在许多问题,由于小编只是熟悉一下pygame,所以并没做更深层次的改进。放到这里,一方面记录自己的学习进度,另一方面也希望有想在游戏方面开发的朋友继续改进。
改进建议一:敌方飞机设置的太多,游戏体验不是很好(这个问题,可以对aliens函数进行修改,从而修改敌方飞机的存在个数等)
改进建议二:每当玩家关闭游戏并重新开启时候,最高分都会被重置(这个问题,可以调用在sys.exit()前,将最高分写入文件,并在游戏记录里面初始化最高分并且读取它)
改进建议三:可以扩展游戏,比如让外星人也可以射击飞船,或者外星人加盾等
改进建议四:可以给游戏加上音效,让玩家得到更好的游戏体验
改进建议五:可以在关卡后面,提高难度不止是敌方飞机速度的加快,也可以是更难打
改进建议六 :可以设置双人游戏,在一台操作器上面
改进建议七:可以设置局域网,让多人联网操作(但是操作只是让设计者熟悉局域网的代码设置)
(。。。。以后有什么更好的想法,可以补上来,要是有时间或者做这个方向的话,可以再扩展这个代码,这个项目是参考《python编程从入门到实践 》的项目)