pygame.sprite.groupcollide() 尝试在 pygame 中实施碰撞时不起作用

Question

我正在做一个贪吃蛇游戏项目，我不能让蛇和食物发生碰撞。在阅读了一些 Pygame 文档之后，我决定使用 pygame.sprite.groupcollide 来处理碰撞。我的游戏中有两种精灵：

蛇
食物

pygame.sprite.groupcollide 在我以前的游戏中有效（来自 Python 一本书的外星人入侵游戏）；但是，出于某种原因，它在我当前的游戏中不起作用。您认为可能是什么原因？这是碰撞部分的亮点（snake_game.py）：

def _check_snake_food_collisions(self):
        '''Check the collisions between the snake and foods.'''
        collisions = pygame.sprite.groupcollide(self.foods, self.snake_parts, True, False)

这是我的代码：

snake_game.py

import pygame
import sys

from random import randint

from settings import Settings 
from snake import Snake
from food import Food 

class SnakeGame:
    '''The main class of the game.'''

    def __init__(self):
        '''Initialize the game assets, screen, etc.'''
        pygame.init()
        self.settings = Settings()
        
        self.screen = pygame.display.set_mode((self.settings.screen_width,
                            self.settings.screen_height))
        pygame.display.set_caption("Snake Game")

        self.snake_parts = pygame.sprite.Group() #Will do some refactoring here.
        self.snake_part = Snake(self)  # Will move this part elsewhere.
        self.snake_parts.add(self.snake_part)
        
        self.foods = pygame.sprite.Group()
        self.food = Food(self)          # Will do some refactoring here as well.
        self.foods.add(self.food)       # Will move this part elsewhere.
       
    def run_game(self):
        '''The main loop of the game.'''
        while True:
            self._check_events()
            self._update_snake_parts()
            self._update_screen()

    def _check_events(self):
        '''Check all the events.'''
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                sys.exit()
            elif event.type == pygame.KEYDOWN:
                self._check_keydown_events(event)
            elif event.type == pygame.KEYUP:
                self._check_keyup_events(event)

    def _check_keydown_events(self, event):
        '''Check keydown events.'''
        if event.key == pygame.K_UP or event.key == pygame.K_w:
            self.snake_part.m_up = True
        elif event.key == pygame.K_DOWN or event.key == pygame.K_s:
            self.snake_part.m_down = True
        elif event.key == pygame.K_LEFT or event.key == pygame.K_a:
            self.snake_part.m_left = True
        elif event.key == pygame.K_RIGHT or event.key == pygame.K_d:
            self.snake_part.m_right = True
        elif event.key == pygame.K_q:
            sys.exit()

    def _check_keyup_events(self, event):
        '''Check keyup events.'''
        if event.key == pygame.K_UP or event.key == pygame.K_w:
            self.snake_part.m_up = False
        elif event.key == pygame.K_DOWN or event.key == pygame.K_s:
            self.snake_part.m_down = False
        elif event.key == pygame.K_LEFT or event.key == pygame.K_a:
            self.snake_part.m_left = False
        elif event.key == pygame.K_RIGHT or event.key == pygame.K_d:
            self.snake_part.m_right = False

    def _check_snake_food_collisions(self):
        '''Check the collisions between the snake and foods.'''
        collisions = pygame.sprite.groupcollide(self.foods, self.snake_parts, True, False)
      
    def _update_snake_parts(self):
        '''Update all the parts of the snake.'''
        self.snake_parts.update()
        
    def _update_screen(self):
        '''Update the screen.'''
        self.screen.fill(self.settings.bg_color)

        # Draw snake parts to the screen.
        for snake_part in self.snake_parts.sprites():
            snake_part.draw_part()

        # Draw foods to the screen.
        self.food.draw_food()

        pygame.display.flip()

if __name__ == '__main__':
    sg = SnakeGame()
    sg.run_game()

snake.py

import pygame
import sys

from pygame.sprite import Sprite 

class Snake(Sprite):
    '''A class to manage the snake.'''

    def __init__(self, sg):
        '''Initialize the snake's location, size, etc.'''
        super().__init__()
        self.screen = sg.screen
        self.settings = sg.settings
        self.color = self.settings.snake_color
        self.screen_rect = self.screen.get_rect()
        
        # Create the snake's rect object and position it.
        self.rect = pygame.Rect(0,0, self.settings.snake_width,
                            self.settings.snake_height)
        self.rect.center = self.screen_rect.center

        # Get the precise coordinates of the snake.
        self.x = float(self.rect.x)
        self.y = float(self.rect.y)

        # Set movement flags.
        self.m_right = False
        self.m_left = False
        self.m_up = False
        self.m_down = False

    def update(self):
        '''Update the position of the snake.'''
        if self.m_right and self.rect.right < self.screen_rect.right:                    
            self.x += self.settings.snake_speed
        if self.m_left and self.rect.left > self.screen_rect.left:
            self.x -= self.settings.snake_speed
        if self.m_down and self.rect.bottom < self.screen_rect.bottom:
            self.y += self.settings.snake_speed
        if self.m_up and self.rect.top > self.screen_rect.top:
            self.y -= self.settings.snake_speed

        self.rect.x = self.x
        self.rect.y = self.y
        
    def draw_part(self):
        '''Draw the snake to the screen.'''
        pygame.draw.rect(self.screen, self.color, self.rect)

food.py

import pygame

from random import randint
from pygame.sprite import Sprite 

class Food(Sprite):
    '''A class to manage the foods.'''

    def __init__(self, sg):
        '''Initialize the food rect, food color, and other assets.'''
        super().__init__()
        self.screen = sg.screen
        self.settings = sg.settings
        self.color = self.settings.food_color
        
        self.rect = pygame.Rect(0, 0, self.settings.food_width,
                        self.settings.food_height)

        # Initialize the food at a random position.
        self.spawn_food()
    
    def spawn_food(self):
        '''Position the food at a random position.'''
        self.rect.x = randint(0, self.settings.screen_width - 
                        self.settings.food_width) 
        self.rect.y = randint(0, self.settings.screen_height - 
                        self.settings.food_height) 

    def draw_food(self):
        '''Draw the food to the screen.'''
        pygame.draw.rect(self.screen, self.color, self.rect)

settings.py

class Settings:
    '''Class for game settings.'''

    def __init__(self):
        '''Initialize the game settings.'''

        # Screen settings
        self.screen_width = 1200
        self.screen_height = 800
        self.bg_color = (119, 181, 254)  # Blue color

        # Snake settings
        self.snake_width = 20
        self.snake_height = 20
        self.snake_color = (255, 255, 0)  # Yellow color
        self.snake_speed = 1

        # Food settings
        self.food_width = 10
        self.food_height = 10
        self.food_color = (139, 69, 19)  # Brown color

Answer 1

阅读pygame.sprite.groupcollide的文档：

[...] If either dokill argument is True, the colliding Sprites will be removed from their respective Group.

当你做的时候

collisions = pygame.sprite.groupcollide(self.foods, self.snake_parts, True, False)

并检测到碰撞，食物从 Group self.foods 中移除。但是，self.food 属性仍然引用 Food 对象。

食物在组中，直到检测到碰撞。因此，您必须绘制 Group self.foods 中的对象，而不是 Sprite 对象 self.food 中的对象。您甚至不需要 self.food 属性。如果所有 Food 个对象都包含在 self.foods:

中就足够了

~~self.food.draw_food()~~

for food in self.foods.sprites():
    food.draw_food()

请注意，您的代码实际上并未调用 _check_snake_food_collisions。

pygame.sprite.groupcollide() 尝试在 pygame 中实施碰撞时不起作用

pygame.sprite.groupcollide() does not work when trying to implement collision in pygame

python

pygame

collision