python - Pygame:子弹粘在屏幕上

Question

我的问题很简单。如果我快速射击，我发射的子弹会粘在屏幕上。如果我慢慢射击，它们就不会粘住。有人知道这种现象是如何发生的吗？

粘在屏幕上的子弹截图

下面我输入了代码。我遵循这个默认的游戏流程图:

我很好奇问题的根源。是代码还是硬件？

import sys
import pygame
from pygame.sprite import Sprite
from pygame.sprite import Group

# pygame initializing
pygame.init()

#create the screen surface
screen =  pygame.display.set_mode((800, 700))

class Color():
    def __init__(self):
        self.black = (0, 0, 0)
        self.white = (255, 255, 255)
        self.red = (255, 0, 0)
        self.green = (0, 255, 0)
        self.green_lambda = (10, 255, 150)
        self.blue = (0, 0, 255)

# set up the colors
color = Color() # make an instance of this class - this makes some colors available

class Spaceship(Sprite):
    """
    This class represents the Spaceship.
    It derives from the "Sprite" class in Pygame.
    """
    def __init__(self):
        """ Constructor"""
        # Call the parent class (Sprite) constructor
        super().__init__()

        width = 22
        height = 32
        self.screen = screen
        self.image = pygame.Surface((width, height))
        self.image.fill(color.black)
        self.image.set_colorkey(color.black)

        pygame.draw.polygon(self.image, color.green_lambda, [[10,0],[15,22],[20,30],[10,27],[0,30],[5,22]],2)

        self.rect = self.image.get_rect()

        self.screen_rect = self.screen.get_rect()
        self.rect.centerx = self.screen_rect.centerx
        self.rect.bottom = self.screen_rect.bottom

        # As the rect method only take integers we store a
        # This value is only used at the beginning, i.e. before the game loop starts
        self.center_x = self.rect.centerx
        self.center_y = self.rect.centery


class Bullet(Sprite):
    """
        This class represents the bullets.
        It derives from the "Sprite" class in Pygame.
    """
    def __init__(self):
        # Call the parent class (Sprite) constructor
        super().__init__()

        self.image = pygame.Surface((8,10))
        self.image.fill(color.red)
        self.image.set_colorkey((color.red))
        pygame.draw.ellipse(self.image, color.green, [1, 0, 5, 8], 2)

        self.rect = self.image.get_rect()

        self.rect.centerx = defender.rect.centerx
        self.rect.bottom = defender.rect.top

    # def function to move the bullets
    def update_pos(self):
        self.rect.y -= bullet_speed


# create spaceship instance
defender = Spaceship()

# create group to store sprites in
all_sprites_list = Group()
all_sprites_list.add(defender)

ship_speed = 0.5
bullet_speed = 3


def run_game():
    m_right = False
    m_left = False
    m_up = False
    m_down = False
    new_bullet = False

    while True:
        """This is the user interaction section"""
        for event in pygame.event.get():
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_ESCAPE:
                    sys.exit()
                elif event.key == pygame.K_RIGHT:
                    m_right = True
                elif event.key == pygame.K_LEFT:
                    m_left = True
                elif event.key == pygame.K_UP:
                    m_up = True
                elif event.key == pygame.K_DOWN:
                    m_down = True
                elif event.key == pygame.K_SPACE:
                    new_bullet = Bullet()
                    #print(dir(new_bullet))
                    all_sprites_list.add(new_bullet)
            if event.type == pygame.KEYUP:
                if event.key == pygame.K_RIGHT:
                    m_right = False
                elif event.key == pygame.K_LEFT:
                    m_left = False
                elif event.key == pygame.K_UP:
                    m_up = False
                elif event.key == pygame.K_DOWN:
                    m_down = False

        """Below is the game logic, which gets input from the user interaction 
        section and more"""
        # Movement of spaceship depending on the flag boolean value and on screen width and height
        if m_right and defender.rect.right < defender.screen_rect.right:
            defender.center_x += ship_speed
        if m_left and defender.rect.left > defender.screen_rect.left:
            defender.center_x -= ship_speed
        if m_up and defender.rect.top > defender.screen_rect.top:
            defender.center_y -= ship_speed
        if m_down and defender.rect.bottom < defender.screen_rect.bottom:
            defender.center_y += ship_speed

        # The cumulative value (which is a float number) for the spaceships movement
        # is given to the spaceship rect variable (which can only be integer) now.
        # This enables fine adjusting of the speed
        defender.rect.centerx = defender.center_x
        defender.rect.centery = defender.center_y
        all_sprites_list.update()
        screen.fill(color.black)
        if new_bullet:
            new_bullet.update_pos()
            # Below the bullets which leaves the screen display are deleted
            if new_bullet.rect.bottom < defender.screen_rect.top:
                all_sprites_list.remove(new_bullet)
        all_sprites_list.draw(screen)
        print(all_sprites_list)
        pygame.display.flip()

run_game()

Answer 1

而不是仅仅更新 new_bullet 的位置

    # if new_bullet:
    #     new_bullet.update_pos()
    #     # Below the bullets which leaves the screen display are deleted
    #     if new_bullet.rect.bottom < defender.screen_rect.top:
    #         all_sprites_list.remove(new_bullet)

更新所有子弹的位置

    for bullet in all_sprites_list:
        if isinstance(bullet,Bullet):
            bullet.update_pos()
            if bullet.rect.bottom < defender.screen_rect.top:
                all_sprites_list.remove(bullet)
                del bullet