The two questions left before , Because the game interface settings are relatively small , The rocket will appear faster as it moves , It just moves out of the interface , What needs to be improved is the speed of the rocket and the setting of the screen edge , The rocket stops moving when it reaches the edge of the screen .
The rocket needs to be set up in settings Class , Add a rocket speed attribute here ：
self.ship_speed = 0.5
Define a new attribute that can store floating-point data , It is used to store the position information and transform the position information according to the speed , Finally, the position information is transmitted to update the position attribute of the control spacecraft .（ When it is passed back, the data type is different , The decimal part will be automatically removed , But it's not a big problem , There's no need to study here ）
# In spaceship properties center Small value stored in , Transfer location information
self.centerx = float(self.image_rect.centerx)
self.centery = float(self.image_rect.centery)
Don't let the rocket move out of the screen , Just monitor the coordinates of the outer rectangular edge of the spacecraft , Keep it from touching the screen edge coordinates , adopt if Judge statements to detect , Not only should keyboard events be detected , Also determine whether the rocket position is in contact with the edge of the screen , Only when both are satisfied can the move command be executed , adopt self.centerx,self.centery To change the position , Finally, pass the value back , Update the value of the location .
def update(self):
''' Respond to the position of the spacecraft according to the moving signs '''
if self.moving_right and self.image_rect.right < self.screen_rect.right:
self.centerx += self.mg_settings.ship_speed
if self.moving_left and self.image_rect.left > 0:
self.centerx -= self.mg_settings.ship_speed
if self.moving_up and self.image_rect.top >0:
self.centery -= self.mg_settings.ship_speed
if self.moving_down and self.image_rect.bottom < self.screen_rect.bottom:
self.centery += self.mg_settings.ship_speed
# according to self.center to update rect object
self.image_rect.centerx = self.centerx
self.image_rect.centery = self.centery
（ The coordinate value in the upper left corner of the screen （0,0））
We can set the bullet class , When we press a specific key value , Rockets can fire bullets .
Bullets can be used directly pygame.Rect() Or is it pygame Other methods in the package , But when you need to create a specific image , You can import pictures as bullets to shoot , It looks more comfortable . The approximate method is the same as that of the rocket , But the position is at the top center of the rocket ：
self.image_bullet_rect.centerx = ship.image_rect.centerx
self.image_bullet_rect.top = ship.image_rect.top
Create a bullet Class to store bullet settings separately . Don't talk much , Look at the code ！
bullet.py
import pygame
from pygame.sprite import Sprite
class Bullet(Sprite):
''' Create a class to manage the spacecraft '''
def __init__(self, mg_settings, screen, ship):
''' Create a bullet object where the ship is located '''
super(Bullet, self).__init__()
self.screen = screen
# Load the missile image and get the circumscribed rectangle
self.image_bullet = pygame.image.load("C:\python Project documents \ practice 002\image\ missile .bmp")
self.image_bullet_rect = self.image_bullet.get_rect()
self.image_bullet_rect.centerx = ship.image_rect.centerx
self.image_bullet_rect.top = ship.image_rect.top
# Store the position of the bullet in decimal
self.y = float(self.image_bullet_rect.y)
self.bullet_speed = mg_settings.bullet_speed
def update(self):
''' Move the bullet up '''
# Update the decimal value indicating the moving position of the bullet
self.y -= self.bullet_speed
# Update indicates bullets rect The location of
self.image_bullet_rect.y = self.y
def draw_bullet(self):
''' Draw bullets on the screen '''
self.screen.blit(self.image_bullet, self.image_bullet_rect)
Other modules are basically unchanged , The relevant codes changed are as follows ：
main_game.py
# Create a spaceship
ship = Ship(mg_settings, screen)
# Create a group to store bullets
bullets = Group()
# Start the main cycle of the game
while True:
gf.check_enents(mg_settings, screen, ship, bullets)# Detect keyboard events
ship.update()# Update the screen when a keyboard event is detected
bullets.update()
gf.update_screen(mg_settings, screen, ship, bullets)
run_game()
game_func.py
def check_enents(mg_settings, screen, ship, bullets):
''' Respond to key and mouse events '''
......
elif event.key == pygame.K_SPACE:
# Create a bullet , And add it to the group bullets in
new_bullet = Bullet(mg_settings, screen, ship)
bullets.add(new_bullet)
......
def update_screen(mg_settings, screen, ship, bullets):
''' Update image on screen , And switch to the new screen '''
# Redraw the screen every time you cycle
screen.fill(mg_settings.screen_color)
# Redraw all bullets behind aliens and spaceships
for bullet in bullets.sprites():
bullet.draw_bullet()
ship.blitme()
# Make the most recently drawn screen visible
pygame.display.flip()
settings.py
# Create a separate class to store the interface settings required for the game
class Settings():
def __init__(self):
self.screen_w = 400
self.screen_h = 300
self.screen_color = 255,255,255
self.ship_speed = 0.3
# Bullet speed setting
self.bullet_speed = 0.1
Through the above changes , The rocket can move up, down, left and right without moving off the screen , Press the space bar to fire bullets .
The renderings are as follows ：
Later, various effects of the game interface will be updated , Add game features , such as ,,,
Ask me what I have , There are only white clouds in the mountains . I can only enjoy myself , I can't bear to give it to you ： Part of the reason is beneficial to me , Not necessarily universal . Limited by some viewpoints , It is hard to avoid being biased and subjective . Part of the writing is unequivocal , It does not mean that we firmly believe in its sole correctness , I just don't want to be all inclusive and ambiguous . If you have any mistakes or opinions, please correct them ！
Solo , Not as happy as others ： Writing is fun , Comment is music , It's fun to see , Music is the most important .
