[python] 小游戏

　　GitHub：https://github.com/liqingwen2015/play_plane

　　目前只做了第一部分：一个界面，有个飞机，可以左右移动，放子弹。

　　暂无计划做第二部分。

　　alien_invasion.py

import sys

import pygame

from settings import Settings
from ship import Ship
import game_functions as gf
from pygame.sprite import Group

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.screnn_height))
    pygame.display.set_caption('Alien Invasion')

    # 创建一艘飞船
    ship = Ship(ai_settings, screen)
    # 创建一个存储的子弹组
    bullets = Group()

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

    # 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_screen(ai_settings, screen, ship, bullets)

run_game()

　　bullet.py

import pygame

from pygame.sprite import Sprite

class Bullet(Sprite):

    def __init__(self, ai_settings, screen, ship):
        super(Bullet, self).__init__()
        self.screen = screen

        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

        # 存储用小数表示的子弹位置
        self.y = float(self.rect.y)

        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
        self.rect.y = self.y

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

　　game_functions

import sys

import pygame

from bullet import Bullet


def check_events(ai_settings, screen, ship, bullets):
    # 监听键盘和鼠标的事件
    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)


def update_screen(ai_settings, screen, ship, bullets):
    # 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.sprites():
        bullet.draw_bullet()

    ship.blitme()

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

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_SPACE:
        # 创建一颗子弹，并将其加入到编组 bullets 中
        fire_bullet(ai_settings, screen, ship, bullets)

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

def update_bullets(bullets):
    bullets.update()

    # 删除已经消失的子弹
    for bullet in bullets.copy():
        if bullet.rect.bottom <= 0:
            bullets.remove(bullet)

def fire_bullet(ai_settings, screen, ship, bullets):
    if len(bullets) < ai_settings.bullets_allowed:
        new_bullet = Bullet(ai_settings, screen, ship)
        bullets.add(new_bullet)

　　settings.py

class Settings():

    def __init__(self):
        # 屏幕设置
        self.screen_width = 1200
        self.screnn_height = 800
        self.bg_color = (230, 230, 230)

        self.ship_speed_factor = 1.5

        # 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 = 5

　　ship.py

import pygame

class Ship():

    def __init__(self, ai_settings, screen):
        self.screen = screen
        self.ai_settings = ai_settings

        # 加载飞船图像并获取其外接矩形
        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)

        # 移动标识
        self.moving_right = False
        self.moving_left = False

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

    def update(self):
        if self.moving_right and self.rect.right < self.screen_rect.right:
            self.center += self.ai_settings.ship_speed_factor
        elif self.moving_left and self.rect.left > 0:
            self.center -= self.ai_settings.ship_speed_factor

        # 更新 rect 对象
        self.rect.centerx = self.center