python小项目之飞机大战

今天想用pygame库写一个击打外星人飞船的python程序

这个游戏的效果是操纵一个位于屏幕底端的飞船，通过上下左右控制飞船移动方向，按空格发射子弹。游戏中击杀一批飞船后进入下一关卡。每一关卡击打飞船获得的得分递增。若外星飞船触碰飞船或屏幕底端则减一条命。最终计算总得分。

游戏中主要包括了：飞船对象，alien对象，子弹对象，游戏设置，游戏状态，游戏控制按钮，计分板。

1.飞船部分

由于pygame中已有sprite类，故飞船可直接继承sprite类
注意在继承类时class中标注继承了什么类，_ init _函数中要使用super(Ship,self).init()来完成继承工作。同时init中也引入了ai—setting和screen（这些部分的代码会在后面写出）

然后为了构建这个飞船的形态，需要在当前文件夹中保存一个飞船的图像。初始化时设置飞船矩形（rect）的中心与游戏界面的中心位于同一垂直线上，飞船底部位于屏幕底端。初始化时定义四个位移变量（上下左右）并设置为false，以便后面按键时对其进行改变。
接下来定义了update函数，这个函数的作用是改变飞船的当前状态，如按下←键时使得飞船左移。同时需要注意：飞船的左侧不能超过屏幕的左端，否则会很影响游戏体验。其余同理。
然后是blitme函数，这个函数完成了将飞船状态及时更新在屏幕上的工作。
最后写了一个centership函数，是用来在需要的时刻将飞船重新放置到屏幕中央。

import pygame
from pygame.sprite import Sprite

class Ship(Sprite):#继承sprite类

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.bmp')
self.rect=self.image.get_rect()
self.screen_rect=screen.get_rect()

self.rect.centerx=self.screen_rect.centerx
self.rect.bottom=self.screen_rect.bottom

self.center=float(self.rect.centerx)
self.high=float(self.rect.bottom)

self.moving_right=False
self.moving_left=False
self.moving_up=False
self.moving_down=False

def update(self):
if self.moving_right and self.rect.right<self.screen_rect.right:
#self.rect.centerx+=1
self.center+=self.ai_settings.ship_speed_factor_horizen
if self.moving_left and self.rect.left>self.screen_rect.left:
#self.rect.centerx-=1
self.center-=self.ai_settings.ship_speed_factor_horizen
if self.moving_up and self.rect.top>self.screen_rect.top:

self.high-=self.ai_settings.ship_speed_factor_height
if self.moving_down and self.rect.bottom<self.screen_rect.bottom:

self.high+=self.ai_settings.ship_speed_factor_height

self.rect.centerx=self.center
self.rect.bottom=self.high

def blitme(self):

self.screen.blit(self.image,self.rect)
def center_ship(self):
self.center=self.screen_rect.centerx

给出alien部分：
alien部分生成了飞船群
然后为了产生初始的随机方向飞行，引入了random库。
同样的，这里的alien也继承了Sprite精灵。
注意，这里的飞船图像必须保存在当前文件夹下，然后用pygame.load来加载图片。
一个细节，由于alien移动距离是浮点型，所以要先计算移动的浮点类型，最后将其转换成整形以保证移动的连续性。同时由于alien图像必须保证一直处在screen内，所以这里定义了一个方法check_edges，通过self.screen.get_rect()来获取屏幕的位置，将alien与screen都视为矩形，比较两者的边界即可。

import pygame
import random##########
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

self.image=pygame.image.load('images/alien.bmp')
self.rect=self.image.get_rect()

self.rect.x=self.rect.width#-20
self.rect.y=self.rect.height#-20

self.direction=random.choice([1,-1])

self.x=float(self.rect.x)

def check_edges(self):
screen_rect=self.screen.get_rect()
if self.rect.right>=screen_rect.right:
return True
elif self.rect.left<=screen_rect.left:
return True

def blitme(self):
self.screen.blit(self.image,self.rect)

def update(self):
#由于x可以精确到小数，故先更新x，再用x更新rect
self.x+=(self.ai_settings.alien_speed_factor*
self.direction)#*random.choice([1,-1])#####
self.rect.x=self.x

给出bullet部分。
bullet同ship，alien一样，也继承了sprite。
注意，由于子弹是由飞船从飞船上部发出，故初始化子弹时要将其位置设置在飞船上部中央，子弹大小也不能过大。因为子弹大小较小，所以用pygame中的draw.rect(self.screen,self.color,self.rect)来画出一个小矩形即可，这种方法比较省事。如果想要使子弹的形状更加美观，可以用上面ship和alien中加载位图的方式。

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.bottom=ship.rect.bottom

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
self.rect.y=self.y

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

给出游戏设置部分。
我们把游戏中所有涉及数据的部分都放在这个文件中，包括了屏幕，速度，子弹，飞船，外星人，游戏节奏以及游戏关卡更新。

class Settings():
"""存储所有设置的类"""
def __init__(self):
self.high_score=0

#屏幕设置
self.screen_width=1200
self.screen_height=650
self.bg_color=(230,230,230)
#速度设置
self.ship_speed_factor_horizen=1
self.ship_speed_factor_height=0.5
self.ship_limit=3

#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

#外星人设置
self.alien_speed_factor=1
self.fleet_drop_speed=10
#direction为1表示右移，-1表示左移
self.fleet_direction=1
self.alien_points=50

#游戏节奏设置
self.speedup_scale=1.1
self.score_scale=1.5

self.initialize_dynamic_settings()

def initialize_dynamic_settings(self):
self.ship_speed_factor=1.5
self.bullet_speed_factor=3
self.alien_speed_factor=1

self.fleet_direction=1

def increase_speed(self):
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)

给出游戏状态部分。
将游戏中的状态部分都放置在这个文件中。

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

由于游戏初始通常有一个START按钮用于开始游戏，所以这里需要定义一个按钮类。这里需要引入pygame.font用于其中的字体部分。
loading…

import pygame.font

class Button():

def __init__(self,ai_settings,screen,message):
'''初始化按钮的属性'''
self.screen=screen
self.screen_rect=screen.get_rect()

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)

self.rect=pygame.Rect(0,0,self.width,self.height)
self.rect.center=self.screen_rect.center

self.prep_message(message)

def prep_message(self,message):
#图像渲染
self.message_image=self.font.render(message,True,self.text_color,
self.button_color)
self.message_image_rect=self.message_image.get_rect()
self.message_image_rect.center=self.rect.center

def draw_button(self):
self.screen.fill(self.button_color,self.rect)
self.screen.blit(self.message_image,self.message_image_rect)

给出计分板部分：

import pygame.font
from pygame.sprite import Group

from ship import Ship

class Scoreboard():

def __init__(self,ai_settings,screen,stats):
self.screen=screen
self.screen_rect=screen.get_rect()
self.ai_settings=ai_settings
self.stats=stats

self.text_color=(30,30,30)
self.font=pygame.font.SysFont(None,48)

self.prep_score()
self.prep_high_score()
self.prep_history_high_score()##########
self.prep_level()
self.prep_ships()

def prep_score(self):
'''将得分渲染成图像'''
rounded_score=int(round(self.stats.score,-1))
score_str="score:"+"{:,}".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#存疑

def prep_high_score(self):
high_score=int(round(self.stats.high_score,-1))
high_score_str="High score:"+"{:,}".format(high_score)
self.high_score_image=self.font.render(high_score_str,True,
self.text_color,self.ai_settings.bg_color)
self.high_score_rect=self.high_score_image.get_rect()
self.high_score_rect.centerx=self.screen_rect.centerx-195
self.high_score_rect.top=self.score_rect.top

def prep_history_high_score(self):###########
with open("highscore.txt") as file1:
lines=file1.readlines()
temp_string=''
for line in lines:
temp_string+=line.rstrip()
history_high_score=eval(temp_string)
history_high_score_str="Highest score:"+"{:,}".format(history_high_score)
self.history_high_score_image=self.font.render(history_high_score_str,
True,self.text_color,self.ai_settings.bg_color)
self.history_high_score_rect=self.history_high_score_image.get_rect()
self.history_high_score_rect.left=self.high_score_rect.right+45
self.history_high_score_rect.top=self.high_score_rect.top

def prep_level(self):
self.level_image=self.font.render("Level:"+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):
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)

def show_score(self):
self.screen.blit(self.score_image,self.score_rect)
self.screen.blit(self.high_score_image,self.high_score_rect)
self.screen.blit(self.history_high_score_image,
self.history_high_score_rect)####
self.screen.blit(self.level_image,self.level_rect)
self.ships.draw(self.screen)

给出游戏中用到的各种函数部分：

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

def check_keydown_events(event,ai_settings,stats,screen,ship,bullets):#stats
if event.key==pygame.K_RIGHT:
#向右移动一格
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_bullets(ai_settings,screen,ship,bullets)
elif event.key==pygame.K_q:#按q键退出界面
renew_history_high_score(stats)###########
pygame.quit()
sys.exit()

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

def fire_bullets(ai_settings,screen,ship,bullets):
if len(bullets)<ai_settings.bullets_allowed:

new_bullet=Bullet(ai_settings,screen,ship)
bullets.add(new_bullet)

def check_events(ai_settings,screen,stats,sb,play_button,ship,aliens,
bullets):

for event in pygame.event.get():

if event.type==pygame.QUIT:
renew_history_high_score(stats)###########
pygame.quit()
sys.exit()

elif event.type==pygame.KEYDOWN:
check_keydown_events(event,ai_settings,stats,screen,ship,bullets)
##########stats
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,scr
1c140
een,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):
button_clicked=play_button.rect.collidepoint(mouse_x,mouse_y)
if button_clicked and not stats.game_active:
ai_settings.initialize_dynamic_settings()
#隐藏光标
pygame.mouse.set_visible(False)
#重置统计信息
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
aliens.empty()
bullets.empty()

create_fleet(ai_settings,screen,ship,aliens)
ship.center_ship()

def update_screen(ai_settings,screen,stats,sb,ship,aliens,bullets,play_button):

screen.fill(ai_settings.bg_color)
for bullet in bullets.sprites():
bullet.draw_bullet()
ship.blitme()
#alien.blitme
aliens.draw(screen)
sb.show_score()
#如果处于非活动状态，绘制Play按钮
if not stats.game_active:
play_button.draw_button()
pygame.display.flip()

def check_bullet_alien_collisions(ai_settings,screen,stats,sb,
ship,aliens,bullets):
collisions=pygame.sprite.groupcollide(bullets,aliens,True,True)
if collisions:
for aliens in collisions.values():
stats.score+=ai_settings.alien_points*len(aliens)
#每个值都是一个列表!!!
sb.prep_score()
check_high_score(stats,sb)
if len(aliens)==0:

bullets.empty()
ai_settings.increase_speed()
stats.level+=1
sb.prep_level()
create_fleet(ai_settings,screen,ship,aliens)

def update_bullets(ai_settings,screen,stats,sb,ship,aliens,bullets):
bullets.update()

for bullet in bullets.copy():
if bullet.rect.bottom<=0:
bullets.remove(bullet)
#碰撞后返回一个字典
check_bullet_alien_collisions(ai_settings,screen,stats,sb,
ship,aliens,bullets)

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

def get_number_rows(ai_settings,ship_height,alien_height):
''''计算屏幕可容纳行数'''
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):
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'''
#外星人间距为外星人宽度
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)
total_alien_number=number_aliens_x*number_rows
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 change_fleet_direction(ai_settings,aliens):
for alien in aliens.sprites():
alien.rect.y+=ai_settings.fleet_drop_speed
ai_settings.fleet_direction*=-1########

def ship_hit(ai_settings,stats,sb,screen,ship,aliens,bullets):
if stats.ships_left>0:

stats.ships_left-=1
sb.prep_ships()
aliens.empty()
bullets.empty()

create_fleet(ai_settings,screen,ship,aliens)
ship.center_ship()

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

def check_aliens_bottom(ai_settings,stats,sb,screen,ship,aliens,bullets):
screen_rect=screen.get_rect()
for alien in aliens.sprites():
if alien.rect.bottom>=screen_rect.bottom:
ship_hit(ai_settings,stats,sb,screen,ship,aliens,bullets)
break

def check_fleet_edges(ai_settings,aliens):
for alien in aliens.sprites():
if alien.check_edges():
#change_fleet_direction(ai_settings,aliens)
#break
alien.direction*=-1#random.choice([1,-1])
alien.rect.y+=ai_settings.fleet_drop_speed

#def change_alien_direction()

def check_time(ai_settings,aliens):
now=time.time()
running_time=int(now-start)
if running_time==1:
for alien in aliens.sprites():
alien.direction*=-1#random.choice([1,-1])
alien.rect.y+=ai_settings.fleet_drop_speed

def update_aliens(ai_settings,stats,sb,screen,ship,aliens,bullets):
#check_time(start,ai_settings,aliens)
check_fleet_edges(ai_settings,aliens)
#check_time(ai_settings,aliens)
aliens.update()

if pygame.sprite.spritecollideany(ship,aliens):
ship_hit(ai_settings,stats,sb,screen,ship,aliens,bullets)
check_aliens_bottom(ai_settings,stats,sb,screen,ship,aliens,bullets)

def check_high_score(stats,sb):
if stats.score>stats.high_score:
stats.high_score=stats.score
sb.prep_high_score()

def renew_history_high_score(stats):##########
filename='highscore.txt'
with open(filename) as file_object:
lines=file_object.readlines()
temp_string=''
for line in lines:
temp_string+=line.rstrip()
if stats.high_score>eval(temp_string):
with open(filename,'w') as file:
file.write(str(stats.high_score))

最后给出程序的主要部分
主要部分中引入了pygame ，time以及Group
创建了 飞船对象，alien对象，子弹对象，游戏设置，游戏状态，游戏控制按钮，计分板。

"""
待加入项目:
1.引入历史最高分         ###   已完成
2.加入随机飞行系统       ###   基本完成/衰
"""

import pygame
import time
from pygame.sprite import Group
from game_stats import GameStats

from settings import Settings
from ship import Ship
from alien import Alien
from button import Button
from scoreboard import Scoreboard
import game_functions as gf

def run_game():
#初始化对象并创建一个屏幕对象
pygame.init()           #初始化
ai_settings=Settings()
screen=pygame.display.set_mode((
ai_settings.screen_width,ai_settings.screen_height))
pygame.display.set_caption("Alien Invasion")
#创建一个按钮
play_button=Button(ai_settings,screen,'Play')
ship=Ship(ai_settings,screen)#创建一个飞船

#创建一个子弹编组
bullets=Group()
aliens=Group()
bg_color=(230,230,230)
alien=Alien(ai_settings,screen)
gf.create_fleet(ai_settings,screen,ship,aliens)
#创建存储游戏统计信息的实例，并创建记分牌
stats=GameStats(ai_settings)
sb=Scoreboard(ai_settings,screen,stats)
#start=time.time()
while True:

#监视键盘和鼠标事件
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,stats,sb,screen,ship,aliens,bullets)
gf.update_screen(ai_settings,screen,stats,sb,ship,aliens,bullets,
play_button)

run_game()

chenk_events部分检测了鼠标以及键盘按键