驾驶飞船
- 学会如何控制屏幕图像移动
响应按键
通过方法pygame.event.get()来获取事件,将每次事件都为注册为KEYDOWN事件。
game_functions
import sys
import pygame
def check_event(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:
if event.key == pygame.K_RIGHT:
#向右移动飞船
ship.rect.centerx += 1
def update_screen(ai_settings,screen,ship):
"""更新屏幕上的图像,并切换新屏幕"""
#每次循环时都重绘屏幕
screen.fill(ai_settings.bg_color)
ship.blitme()
#让最近绘制的屏幕可见
pygame.display.flip()
- alien_invasion.py
import sys
import pygame
from settings import Settings
from ship import Ship
import game_functions as gf
def run_game():
#初始化游戏并创建一个屏幕对象
ai_settings = Settings()
pygame.init()
screen = pygame.display.set_mode(
(ai_settings.screen_width,ai_settings.screen_heigth))
pygame.display.set_caption("ALien Invasion")
ship = Ship(screen)
#开始游戏的主循环
while True:
#监视键盘和鼠标事件
# for event in pygame.event.get():
# if event.type == pygame.QUIT:
# sys.exit()
gf.check_event(ship)
gf.update_screen(ai_settings,screen,ship)
run_game()
允许不断移动
结合使用KEYDOWN和KRYUP事件,以及一个moving_right的标识来实现持续运动。
飞船不动是,标识moving_right将为False。玩家按下右箭头键时,将moving_right标识设置为True.而玩家松开时。标识重新设置为False.
飞船的属性是由Ship类控制的,将这个类添加一个名为moving_right的属性和一个update()的方法。
ship.py
import pygame
class Ship():
def __init__(self,screen):
"""初始化飞船并设置初始位置"""
self.screen = screen
# 加载飞船图像并获取外接矩形
self.image = pygame.image.load(r'D:\study_note\python_study\alien_invasion\images\ship.bmp')
self.rect = self.image.get_rect()
self.screen_rect = screen.get_rect()
self.moving_right = False
self.moving_left = False
# 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
def update(self):
"""根据移动标识来调整飞船的位置"""
if self.moving_right:
self.rect.centerx += 1
elif self.moving_left:
self.rect.centerx -= 1
def blitme(self):
"""在指定位置绘制飞船"""
self.screen.blit(self.image,self.rect)
- game_functions.py
import sys
import pygame
def check_event(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:
if event.key == pygame.K_RIGHT:
#向右移动飞船
ship.moving_right = True
elif event.key == pygame.K_LEFT:
ship.moving_left = True
elif event.type == pygame.KEYUP:
if event.key == pygame.K_RIGHT:
ship.moving_right = False
elif event.key == pygame.K_LEFT:
ship.moving_left = False
def update_screen(ai_settings,screen,ship):
"""更新屏幕上的图像,并切换新屏幕"""
#每次循环时都重绘屏幕
screen.fill(ai_settings.bg_color)
ship.blitme()
#让最近绘制的屏幕可见
pygame.display.flip()
-
alien_invasion.py
import sys import pygame from settings import Settings from ship import Ship import game_functions as gf def run_game(): #初始化游戏并创建一个屏幕对象 ai_settings = Settings() pygame.init() screen = pygame.display.set_mode( (ai_settings.screen_width,ai_settings.screen_heigth)) pygame.display.set_caption("ALien Invasion") #设置背景色 # bg_cokor = ai_settings.bg_color() #创建一艘飞船 ship = Ship(screen) #开始游戏的主循环 while True: gf.check_event(ship) ship.update() gf.update_screen(ai_settings,screen,ship) run_game()
调整飞船的速度
在Settings类中添加属性ship_speed_factor,用于控制飞船的速度。
Settings.py
class Settings():
"""存储《外星人入侵》游戏的所有设置类"""
def __init__(self):
"""初始化游戏的设置"""
#屏幕设置
self.screen_width = 1200
self.screen_heigth = 800
self.bg_color = (230,230,230)
self.ship_speed_factor = 1.5
将ship_speed_factor设置为1.5,但是rect的centerx等属性只能存储正数。
对ship.py修改
import pygame
class Ship():
def __init__(self,ai_settings,screen):
"""初始化飞船并设置初始位置"""
self.screen = screen
# 加载飞船图像并获取外接矩形
self.image = pygame.image.load(r'D:\study_note\python_study\alien_invasion\images\ship.bmp')
self.rect = self.image.get_rect()
self.screen_rect = screen.get_rect()
self.moving_right = False
self.moving_left = False
self.ai_settings = ai_settings
# 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
#将飞船的属性center中存储小数值
self.center = float(self.rect.centerx)
def update(self):
"""根据移动标识来调整飞船的位置"""
if self.moving_right:
self.center += self.ai_settings.ship_speed_factor
elif self.moving_left:
self.center -= self.ai_settings.ship_speed_factor
#根据self.center更新rect值
self.rect.centerx = self.center
def blitme(self):
"""在指定位置绘制飞船"""
self.screen.blit(self.image,self.rect)
- 最后修改alien_invasion.py
import sys
import pygame
from settings import Settings
from ship import Ship
import game_functions as gf
def run_game():
#初始化游戏并创建一个屏幕对象
ai_settings = Settings()
pygame.init()
screen = pygame.display.set_mode(
(ai_settings.screen_width,ai_settings.screen_heigth))
pygame.display.set_caption("ALien Invasion")
#设置背景色
# bg_cokor = ai_settings.bg_color()
#创建一艘飞船
ship = Ship(ai_settings,screen)
#开始游戏的主循环
while True:
#监视键盘和鼠标事件
# for event in pygame.event.get():
# if event.type == pygame.QUIT:
# sys.exit()
gf.check_event(ship)
ship.update()
gf.update_screen(ai_settings,screen,ship)
# #每次循环时都重绘屏幕
# screen.fill(ai_settings.bg_color)
# ship.blitme()
# #让最近绘制的屏幕可见
# pygame.display.flip()
run_game()
限制飞船的活动范围
修改ship类的方法update()
ship.py
import pygame
class Ship():
def __init__(self,ai_settings,screen):
"""初始化飞船并设置初始位置"""
self.screen = screen
# 加载飞船图像并获取外接矩形
self.image = pygame.image.load(r'D:\study_note\python_study\alien_invasion\images\ship.bmp')
self.rect = self.image.get_rect()
self.screen_rect = screen.get_rect()
self.moving_right = False
self.moving_left = False
self.ai_settings = ai_settings
# 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
#将飞船的属性center中存储小数值
self.center = float(self.rect.centerx)
def update(self):
"""根据移动标识来调整飞船的位置"""
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
#根据self.center更新rect值
self.rect.centerx = self.center
def blitme(self):
"""在指定位置绘制飞船"""
self.screen.blit(self.image,self.rect)
- self.rect.right返回飞船外接矩形的右边缘的x坐标,如果这个值小于self.screen_rect.right的值,说明飞船未碰及屏幕右边缘
重构check_events()
- 将其部分代码放在两个函数中:一个处理KEYDOWN事件,一个处理KEYUP 事件。
import sys
import pygame
def check_keydown_events(event,ship):
if event.key == pygame.K_RIGHT:
#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):
if event.key == pygame.K_RIGHT:
ship.moving_right = False
elif event.key == pygame.K_LEFT:
ship.moving_left = False
def check_event(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):
"""更新屏幕上的图像,并切换新屏幕"""
#每次循环时都重绘屏幕
screen.fill(ai_settings.bg_color)
ship.blitme()
#让最近绘制的屏幕可见
pygame.display.flip()
射击
- 添加射击功能
添加子弹设置
- 更新settings,在init()末尾存储所需的值
class Settings():
"""存储《外星人入侵》游戏的所有设置类"""
def __init__(self):
"""初始化游戏的设置"""
#屏幕设置
self.screen_width = 1200
self.screen_heigth = 800
self.bg_color = (230,230,230)
self.ship_speed_factor = 1.5
self.bullet_speed_factor = 1
self.bullet_width = 3
self.bullet_height = 15
self.bullet_color = 60.60.60
创建bullet类
import pygame
from pygame.sprite import Sprite
class Bullet(Sprite):
"""对飞船发射的子弹进行管理的类"""
def __init__(self, ai_settings,screen,ship):
super(Bullet, self).__init__()
self.screen = screen
#在(0.0)出创建一个表示子弹的矩形,在设置正确的位置
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):
"""向上移动子弹"""
#更新表示子弹的小数值
self.y -= self.speed_factor
#表示子弹的位置
self.rect.y = self.y
def draw_bullet(self):
"""在屏幕上绘制子弹"""
pygame.draw.rect(self.screen,self.color,self.rect)
- Bullet类继承了我们模块pygame.sprite中导入的sprite类,可以将游戏中相关的元素编组,然后可以操作组中的所有元素。
- 函数draw.rect()用于存储self.color中的颜色填充表示子弹的rect占据屏幕的位置。
将子弹存储在编组中。
- 让玩家每次按空格的时候发射子弹
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
ai_settings = Settings()
pygame.init()
screen = pygame.display.set_mode(
(ai_settings.screen_width,ai_settings.screen_heigth))
pygame.display.set_caption("ALien Invasion")
#设置背景色
# bg_cokor = ai_settings.bg_color()
#创建一艘飞船
ship = Ship(ai_settings,screen)
#创建一个用于存储子弹的编组
bullets = Group()
#开始游戏的主循环
while True:
#监视键盘和鼠标事件
# for event in pygame.event.get():
# if event.type == pygame.QUIT:
# sys.exit()
gf.check_event(ai_settings,screen,ship,bullets)
ship.update()
bullets.update()
gf.update_screen(ai_settings,screen,ship,bullets)
# #每次循环时都重绘屏幕
# screen.fill(ai_settings.bg_color)
# ship.blitme()
# #让最近绘制的屏幕可见
# pygame.display.flip()
run_game()
开火
- 修改game_functions.py
import sys
import pygame
from bullet import Bullet
def check_keydown_events(event,ai_settings,screen,ship,bullets):
if event.key == pygame.K_RIGHT:
#向右移动飞船
ship.moving_right = True
elif event.key == pygame.K_LEFT:
ship.moving_left = True
elif event.key == pygame.K_SPACE:
#创建一个子弹,并将其加入编组bullets中
new_bullet = Bullet(ai_settings,screen,ship)
bullets.add(new_bullet)
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 check_event(ai_settings,screen,ship,bullets):
"""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,ai_settings,screen,ship,bullets)
elif event.type == pygame.KEYUP:
check_keyup_events(event,ship)
def update_screen(ai_settings,screen,ship,bullets):
"""更新屏幕上的图像,并切换新屏幕"""
#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.sprites():
bullet.draw_bullet()
ship.blitme()
#让最近绘制的屏幕可见
pygame.display.flip()
删除已经消失的子弹
- 子弹到达屏幕顶端消失,仅仅是python在屏幕外无法绘制他们,这些子弹依然存在。他们会继续消耗内存和处理能力
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
ai_settings = Settings()
pygame.init()
screen = pygame.display.set_mode(
(ai_settings.screen_width,ai_settings.screen_heigth))
pygame.display.set_caption("ALien Invasion")
#设置背景色
# bg_cokor = ai_settings.bg_color()
#创建一艘飞船
ship = Ship(ai_settings,screen)
#创建一个用于存储子弹的编组
bullets = Group()
#开始游戏的主循环
while True:
gf.check_event(ai_settings,screen,ship,bullets)
ship.update()
bullets.update()
#删除已经消失的子弹
for bullet in bullets.copy():
if bullet.rect.bottom <= 0:
bullets.remove(bullet)
print(len(bullets))
gf.update_screen(ai_settings,screen,ship,bullets)
run_game()
限制子弹的数量
- 在setttings.py中存储所允许的最大的子弹数量
class Settings():
"""存储《外星人入侵》游戏的所有设置类"""
def __init__(self):
"""初始化游戏的设置"""
#屏幕设置
self.screen_width = 1200
self.screen_heigth = 800
self.bg_color = (230,230,230)
self.ship_speed_factor = 1.5
self.bullet_speed_factor = 1
self.bullet_width = 3
self.bullet_height = 15
self.bullet_color = 60,60,60
self.bullet_allowed = 3
- 在game_functions,py的check_keydown_event(),在创建新子弹检查未消失的子弹的数量
class Settings():
"""存储《外星人入侵》游戏的所有设置类"""
def __init__(self):
"""初始化游戏的设置"""
#屏幕设置
self.screen_width = 1200
self.screen_heigth = 800
self.bg_color = (230,230,230)
self.ship_speed_factor = 1.5
self.bullet_speed_factor = 1
self.bullet_width = 3
self.bullet_height = 15
self.bullet_color = 60,60,60
self.bullets_allowed = 3
创建函数update_bullets()
- 在game_gunctions.py添加
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)
- 主程序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
ai_settings = Settings()
pygame.init()
screen = pygame.display.set_mode(
(ai_settings.screen_width,ai_settings.screen_heigth))
pygame.display.set_caption("ALien Invasion")
#设置背景色
# bg_cokor = ai_settings.bg_color()
#创建一艘飞船
ship = Ship(ai_settings,screen)
#创建一个用于存储子弹的编组
bullets = Group()
#开始游戏的主循环
while True:
#监视键盘和鼠标事件
# for event in pygame.event.get():
# if event.type == pygame.QUIT:
# sys.exit()
gf.check_event(ai_settings,screen,ship,bullets)
ship.update()
bullets.update()
#删除已经消失的子弹
gf.update_bullets(bullets)
print(len(bullets))
gf.update_screen(ai_settings,screen,ship,bullets)
# #每次循环时都重绘屏幕
# screen.fill(ai_settings.bg_color)
# ship.blitme()
# #让最近绘制的屏幕可见
# pygame.display.flip()
run_game()
创建函数fire_bullet()
- 修改game_functions.py
import sys
import pygame
from bullet import Bullet
def check_keydown_events(event,ai_settings,screen,ship,bullets):
if event.key == pygame.K_RIGHT:
#向右移动飞船
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 fire_bullet(ai_settings,screen,ship,bullets):
#创建一个子弹,并将其加入编组bullets中
if len(bullets) < ai_settings.bullets_allowed:
new_bullet = Bullet(ai_settings,screen,ship)
bullets.add(new_bullet)
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 check_event(ai_settings,screen,ship,bullets):
"""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,ai_settings,screen,ship,bullets)
elif event.type == pygame.KEYUP:
check_keyup_events(event,ship)
def update_screen(ai_settings,screen,ship,bullets):
"""更新屏幕上的图像,并切换新屏幕"""
#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.sprites():
bullet.draw_bullet()
ship.blitme()
#让最近绘制的屏幕可见
pygame.display.flip()
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)
总结
- 使用pygame编写游戏的基本构建
- 如何设置背景色,
- 如何设置存储在可供游戏的各个部分访问的独立的类。
- 如何在屏幕上绘制图形。
- 如何让玩家控制游戏元素移动。
- 如何创建自动移动的元素
- 如何删除不需要的对象。
- 如何定期重构代码。