Python--Project combat--game frame construction

Goal--using object-oriented design aircraft war game class

Goal

• Clear Main program Responsibilities
• Implementing the Main program class
• Prepare the game Sprite Group

01, clear the main program responsibility

• Review the QuickStart case , the responsibility of a game main program can be divided into two parts
  • Game initialization
  • Game Loop
• According to clear responsibilities, the design PlaneGame class is as follows:

tips to encapsulate a private method according to responsibilities , you can avoid the code of one method being too verbose; If a method is written too long, it is not good to read or to maintain.

• Game Initialization -the __init__() method is called:

Method	Responsibilities
__event_handler(self)	Event Monitoring
__check_collide(self)	Collision detection--bullets destroy enemy planes, enemy planes crash heroes
__update_sprites(self)	Sprite Group Update and draw
__game_over()	Game Over

02, to achieve aircraft vs. main Game Class 2.1 clear document Responsibilities

• plane_main
  • 1, encapsulating the main game class
  • 2. Create a Game object
  • 3, start the game
• plane_sprites
  • Encapsulates all the sprite subclasses that need to be used in the game
  • tools to provide games

Code implementation

• Create plane_main.py a new file and set it to executable
• Writing the underlying code

import pygamefrom Aircraft_War.plane_sprites import *class PlaneGame(object):    """飞机大战主游戏"""    def __init__(self):        print("游戏初始化")        # 1，创建游戏的窗口        self.screen = pygame.display.set_mode((480, 700))        # 2，创建游戏的时钟        self.clock = pygame.time.Clock()        # 3，调用私有方法， 精灵和精灵组的创建        self.__create_sprites()    def __create_sprites(self):        pass    def start_game(self):        print("游戏开始...")if __name__ == ‘__main__‘:    # 创建游戏对象    game = PlaneGame()    # 启动游戏    game.start_game()

Use constants instead of fixed values

• Constant--the quantity that does not change
• Variable--The amount that can be changed

Application Scenarios

• At development time, you may want to use a fixed value , such as the height of the screen700
• At this time, it is recommended not to use fixed values directly, but to use constants
• When developing, try not to use magic numbers in order to maintain code maintainability

Definition of constants

• The syntax for defining constants and defining variables is exactly the same as using assignment statements
• The command for a constant should be that all letters are uppercase, and the words are underlined between the words

The benefits of constants

• When reading code, you don't need to guess the meaning of a number by means of a constant name .
• If you need to adjust the value , you only need to modify the constant definition to achieve uniform modification

hint : Python does not have a really meaningful constant, just by naming the convention--all letters are capitalized in time constants, not easy to modify when developing!

Code Adjustment

• plane_sprites.pyincrease the definition of a constant in

plane_sprites.py

import pygame# 屏幕大小的常量SCREEN_RECT = pygame.Rect(0, 0, 480, 700)# 刷新的帧率FRAME_PER_SEC = 60class GameSprite(pygame.sprite.Sprite):    """飞机大战游戏精灵"""    def __init__(self, image_name, speed=1):        # 调用父类的初始化方法        super().__init__()        # 定义对象的属性        self.image = pygame.image.load(image_name)        self.rect = self.image.get_rect()        self.speed = speed    def update(self, *args):        # 在屏幕的垂直方向上移动        self.rect.y += self.speed

plan_main.py

Import pygamefrom aircraft_war.plane_sprites Import *class planegame (object): "" "Aircraft vs. Main game" "Def __init__ (self): Print ("Game Initialization") # 1, create a game window # self.screen = Pygame.display.set_mode ((480, $)) Self.screen = Pygam E.display.set_mode (screen_rect.size) # 2, create game clock Self.clock = Pygame.time.Clock () # 3, call private method, Sprite and Sprite Group Create Self.__create_sprites () def __create_sprites (self): Pass def start_game (self): print ("game starts.        .") While True: # 1, set refresh frame rate Self.clock.tick (frame_per_sec) # 2, Event listener Self.__event_ha            Ndler () # 3, Collision Detection Self.__check_collide () # 4, update/Draw Sprite Group Self.__update_sprites () # 5, update display pygame.display.update () def __event_handler (self): for event in Pygame.event.get () : # Determine whether to exit the game if Event.type = = Pygame.  Quit:planegame.__game_over () def __check_collide (self):      Pass Def __update_sprites (self): pass @staticmethod def __game_over (): Print ("Game Over") p Ygame. QUIT () exit () if __name__ = = ' __main__ ': # Create game Object games = Planegame () # Start Game game.start_game ()

Python--project combat--game frame setup