@Pygame Tanks war
This is a 2019 New year West electricity Python Course assignment , Freshman course , Only part of the simple content
Running effect Baidu cloud extraction code : abcd
Source code and material package https://download.csdn.net/download/weixin_43872532/12496334

One , Game architecture design

First, determine the classes that need to appear in the game ：Tank（My_tank.Enemy_Tank）,Missile,wall. At the same time, considering that the shell will explode when it hits the tank , The essence of explosion is to display pictures of constantly enlarged explosion shapes in turn , Set a class to explode explode. At the same time, consider that all classes have common properties , Such as ： It's all pictures , Both have the method of displaying pictures on the screen, etc . So set a parent class of all classes Base_item, Therefore, the overall structure of the game is as follows ：

Two , Mainly used in this program pygame function

display： control pygame Show
pygame.display.set_caption（title）： Sets the title of the current window ;
If the display has a window title , Then this function will change the name on the window . Some systems support alternate shorter titles for minimizing display .
pygame.display.set_mode： Initialize screens and windows ;

set_mode（resolution =（0,0）,flags = 0,depth = 0）

This function will create a display Surface. The parameter passed in is the request for the display type . The display actually created will be the best match supported by the system .
resolution The parameter is a pair of numbers representing the width and height .flags Parameters are a collection of other options .depth The parameter represents the number of bits used for the color .

 # Open a window on the screen
screen_width=700
screen_height=400
screen=pygame.display.set_mode([screen_width,screen_height])

pygame.display.update： Update the part of the screen to display the software ;

sprite（ Spirit group ）：sprite Class is intended to be used as a base class for different types of objects in the game ;
There's another basic one Group class , It only stores sprite. Games can create new types of Group class , These classes are customized in the special that they contain sprite Run... On the instance .
Basic sprite Class can include sprite Drawn to the surface.
What is the spirit ?
Elves can be thought of as little pictures , A graphic object that can be moved on a screen , And can interact with other graphic objects . Sprite images can be used pygame Draw the image drawn by the function , It can also be the original image file .
Write your own elf class ,self.image It can be a rectangle , It can also be a file （ picture 、 String, etc. ）. Among them MoveBall Added the function of animation , use Sprite Class to do animation effect is more convenient .
pygame.sprite.Group()： Used to save and manage multiple Sprite Object's container class .
pygame.sprite.spritecollide： If the sprite intersects anything in the group , Then conduct a simple test ;
spritecollideany（sprite,group,collided = None）Sprite Collide with the returning spirit
spritecollideany（sprite,group,collided = None） No conflict
If any one of the elves in the group collides with , Then a wizard in the group will be returned . Returns no if there is no conflict . The collision parameter is a callback function , Used to calculate whether two sprites collide . It should take two sprites as values and return a bool value , Indicates whether they collide . If the collision is not transmitted , Then all elves must have “rect” value , This value is the rectangle of the sprite area , Will be used to calculate collisions .

__init__： Class has a name __init__() Special method （ Construction method ）, This method is called automatically when the class is instantiated , Like this ：

def __init__(self): self.data = []

Class definition __init__() Method , The instantiation of the class will automatically call __init__() Method .

3、 ... and , Main function

1. Tank movement method move（）

2. collision detection stay（） And hit（）

Move() The core of the function is the real-time monitoring and calculation of the coordinates of enemy and our tanks , At the same time, record the previous coordinates . Each moving object needs to select a reference point , For convenience, its upper left corner in any state represents the current position of the object , This is also the idea of using particles to represent objects in Physics . We take the top left of the screen as the coordinate origin , The distance from the left side of the screen is named “left”, The distance from the top of the screen is called “top”, Both values are non negative , That is, neither tank nor shell can move to the outside of the screen . After specifying the size of the screen , The corresponding coordinate system in the first quadrant can be established , Let all objects move in the specified area .
Implementation of mobile mode . The first is the movement of the foundation , It is applied to the movement under the control of the player of our tank , It is also the basis for the movement of enemy tanks under program control . Based on one movement , Move in one direction every time you receive a move command 6 Pixel . The frame rate of the main function is 20FPS, In the duration of one frame , The move command can be executed once , Then the moving speed of the tank is 120 Pixels per second . When pressing different direction keys , Will change the direction of the tank , namely top and left Calculation method of . Enemy tanks will move randomly after generation , The mechanism we set is ： Each is executed in the same direction 6 After a move command , Random direction conversion , Directional movement again , cycle , Finish the exercise .
Hit（） Implementation of function ,hit（） It is used to judge whether the objects in the game collide . The specific detection mechanism is ： adopt pygame.sprite.collide_rect() function , Edge detection between objects , If the edges of two objects overlap or just touch , Call... In time stay() Function to get the previous two positions , Modify their coordinate values , This returns the collided object to a state where it did not collide before .
Stay() function . The function of this function is to record the previous step （front step） The location of , That is, the cache period is one frame , The cache amount of a single object is its set of coordinates .

Four , Commissioning and Debug

1. The bullet cannot disappear when it hits the edge of the screen or when it hits the tank

Question why ： With the spacebar pressed , Generate bullet objects separately , Makes bullet deletion problematic
resolvent ： Show the bullets in the form of a list , use delete Methods , As the screen refreshes, the bullet hits the screen or the tank disappears .

2. The font cannot be displayed properly

Question why ：pygame.font.SysFont() The first parameter of does not use a common font library
Solution ： Use “simsunnsimsun” typeface

3. The tank picture cannot be loaded normally

Question why 1. Tank pictures vary in size
2.load() The function requires the absolute path of the picture , Because everyone has different file paths, this function cannot be loaded normally
resolvent 1： Change the picture resolution to 136*107
resolvent 2： Put the picture and code in the same folder , You can avoid using absolute paths , Then use screen.blit() Function to render a picture object onto a window

4. Enemy tanks cannot be created randomly

Question why ： Start by using the list to create enemy tanks , List append（） Functions can only add members at the end , Can't do random generation or not a real random tank
Solution ： Use pygame The spirit group concept , Use groups to create enemy tanks . When there are a lot of entities in a program , It's going to be quite a hassle to manipulate these entities
pygame Use sprite group to manage sprite drawing and updating , The sprite group is a simple container . Use pygame.sprite.Group() Function to create a sprite group ：

group = pygame.sprite.Group()
group.add(sprite_one)