alien_invasion.py

#coding:gbk
#import sys

import pygame

from settings import Settings

from ship import Ship

import game_functions as gf

def run_game():
    #初始化pygame,设置,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("灰机大战")

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

    #设置背景色
    bg_color = (230, 230, 230)

    #开始游戏主循环
    while True:
        gf.check_events(ship)
        #每次循环时都重新绘制屏幕
        ship.update()
        gf.update_screen(ai_settings,screen,ship)


        #让最近绘制的屏幕可见
        pygame.display.flip()
run_game()

settings.py

#coding:gbk
class Settings():
    #存储游戏的所有设置的类

    def __init__(self):
        #初始化游戏设置
        #屏幕设置
        self.screen_width = 1200
        self.screen_height = 800
        self.bg_color = (230,230,230)

        #飞船的移动速度设置
        self.ship_speed_factor = 1.5

ship.py

#coding:gbk
import pygame

class Ship():

    def __init__(self,ai_settings,screen):
        #初始化飞船并设置其初始位置
        self.screen = screen
        self.ai_settings = ai_settings
        #加载飞船图形并获取其外接矩形
        self.image = pygame.image.load('images/ship.bmp')
        self.rect = self.image.get_rect()
        self.screen_rect = screen.get_rect()

        #将每艘新飞船放在屏幕底部中央
        self.rect.centerx = self.screen_rect.centerx
        self.rect.bottom = self.screen_rect.bottom

        #在飞船的属性center中存储小数值
        self.center = float(self.rect.centerx)
        #移动标志
        self.moving_right =False
        self.moving_left = False

    def update(self):
        #更新飞船的center值,而不是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
        #根据self.center更新rect对象
        self.rect.centerx = self.center 


    def blitme(self):
        #在指定位置绘制飞船
        self.screen.blit(self.image,self.rect)

game_functions.py

#coding:gbk
import sys
import pygame

def check_keydown_events(event,ship):
    #按键响应
    if event.key == pygame.K_RIGHT:
        #则向右移动飞船
        ship.moving_right = True
    elif event.key == pygame.K_LEFT:
        ship.moving_left = True

def check_keyup_events(event,ship):
    #松开响应
    if event.key == pygame.K_RIGHT:
        ship.moving_right = False
    elif event.key == pygame.K_LEFT:
        ship.moving_left = False

def check_events(ship):
    #响应按键和鼠标事件
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()
        elif event.type == pygame.KEYDOWN:
            check_keydown_events(event,ship)
        elif event.type == pygame.KEYUP:
            check_keyup_events(event,ship)


def update_screen(ai_settings,screen,ship):
    #更新屏幕的图像,并切换到新屏幕
    #每次循环都重新绘制屏幕
    screen.fill(ai_settings.bg_color)
    ship.blitme()

    #让最近绘制的屏幕可见
    pygame.display.flip()