外星人移动
alien_invasion.py
import sys
import pygame
from pygame.sprite import Group
from settings import Settings
from ship import Ship
from alien import Alien
import game_functions as gf
def run_game():
#初始化游戏并创建一个屏幕对象
pygame.init()
ai_settings = Settings()
screen = pygame.display.set_mode(
(ai_settings.screen_width, ai_settings.screen_height))
pygame.display.set_caption("Alien Invasion")
#创建一艘飞船
ship = Ship(ai_settings, screen)
#创建一个存储子弹的编组
bullets = Group()
#创建一个外星人编组
aliens = Group()
#创建外星人群
gf.create_fleet(ai_settings, screen, ship, aliens)
#开始游戏的主循环
while True:
gf.check_events(ai_settings, screen, ship, bullets)
ship.update()
gf.update_bullets(bullets)
gf.update_aliens(ai_settings, aliens)
gf.update_screen(ai_settings, screen, ship, aliens, bullets)
run_game()
game_functions.py
import sys
import pygame
from bullet import Bullet
from alien import Alien
def check_keydown_event(event, ai_settings, screen, ship, bullets):
#相应按键
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:
#创建一颗子弹，并将其加入到编组bullets中
fire_bullet(ai_settings, screen, ship, bullets)
elif event.key == pygame.K_q:
sys.exit()
def check_keyup_event(event, ship):
if event.key == pygame.K_RIGHT:
ship.moving_right = False
elif event.key == pygame.K_LEFT:
ship.moving_left = False
if event.key == pygame.K_UP:
ship.moving_up = False
elif event.key == pygame.K_DOWN:
ship.moving_down = False
def check_events(ai_settings, screen, ship, bullets):
#监视键盘和鼠标事件
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
elif event.type == pygame.KEYDOWN:
check_keydown_event(event, ai_settings, screen, ship, bullets)
elif event.type == pygame.KEYUP:
check_keyup_event(event, ship)
def update_bullets(bullets):
#更新子弹的位置，并删除已消失的子弹
#更新子弹的位置
bullets.update()
#删除已消失的子弹
for bullet in bullets.copy():
if bullet.rect.bottom <= 0:
bullets.remove(bullet)
def fire_bullet(ai_settings, screen, ship, bullets):
#如果还没有达到限制，就发射一颗子弹
#创建新子弹，并将其加入到编组bullets中
if len(bullets) < ai_settings.bullets_allowed:
new_bullet = Bullet(ai_settings, screen, ship)
bullets.add(new_bullet)
def update_screen(ai_settings, screen, ship, aliens, bullets):
#更新屏幕上的图像，并切换到新屏幕
#每次循环时都重绘屏幕
screen.fill(ai_settings.bg_color)
#在飞船和外星人后面重绘所有子弹
for bullet in bullets:
bullet.draw_bullet()#子弹绘制
ship.blitme()
aliens.draw(screen)
#让最近绘制的屏幕可见
pygame.display.flip()
def get_number_aliens_x(ai_settings, alien_width):
#计算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, alien_height):
#计算屏幕可容纳多少行外星人
available_space_y = (ai_settings.screen_height -
(3 * alien_height) - ship_height)
number_rows = int(available_space_y / (2 * alien_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行
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，并计算一行可容纳多少个外星人
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):
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采取的措施
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其方向
for alien in aliens.sprites():
alien.rect.y += ai_settings.fleet_drop_speed
ai_settings.fleet_direction *= -1
def update_aliens(ai_settings, aliens):
#检查是否有外星人位于屏幕边缘，并更新外星人群的位置
check_fleet_edges(ai_settings, aliens)
aliens.update()
settings.py
class Settings():
#《外星人入侵》的所有设置的类""
def __init__(self):
#初始化游戏的设置""
#屏幕设置
self.screen_width = 1200
self.screen_height = 700
self.bg_color = (255, 192, 203)
#飞船的设置
self.ship_speed_factor = 1.5
#外星人设置
self.alien_speed_factor = 1
self.fleet_drop_speed = 10
#fleet_direction为1表示向右移，为-1表示向左移
self.fleet_direction = 1
#子弹设置
self.bullet_speed_factor = 1
self.bullet_width = 3
self.bullet_height = 15
self.bullet_color = 60, 60, 60
self.bullets_allowed = 3
alien.py
import pygame
from pygame.sprite import Sprite
class Alien(Sprite):
#表示单个外星人的类
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，并设置其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左上角附近
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 blitme(self):
#在指定位置绘制外星人
self.screen.blit(self.image, self.rect)
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):
#向左或向右移动外星人
self.x += (self.ai_settings.alien_speed_factor *
self.ai_settings.fleet_direction)
self.rect.x = self.x