为什么我在 PyGame 中得到空白的灰色背景而不是动画? [英] Why do I get blank grey background instead of animations in PyGame?

问题描述

我正在创建 Environment 类.函数init应该构建模拟环境，而函数run应该在10秒内在这个环境中执行不同的事件.

I am creating the Environment class. The function init should build the simulated environment, while the function run should execute different events in this environment during 10 seconds.

下面我分享我的代码的一些主要部分.当我运行 env = Environment("TEST") env.run() (见下文)时，出现灰屏窗口.然后它会在 10 秒内关闭.此屏幕中没有任何内容.这只是一个灰色的背景.但是，我没有收到任何错误消息.

Below I share some major parts of my code. When I run env = Environment("TEST") env.run() (see below), the window with grey screen appears. Then it closes in 10 seconds. Nothing is visible in this screen. It's just a grey background. However, I do not get any error message.

我在 Environment 类中做错了什么?

What am I doing wrong in the Environment class?

只是提一下，当我将 Environment 的整个代码直接放在 main 循环中时，相同的代码可以正常工作，即当 Environment类不存在.

Just to mention that the same code worked fine when I had the whole code of Environment placed directly in main loop, i.e. when Environment class has not existed.

import numpy as np
import pygame
import random

WHITE = (255, 255, 255)
GREEN = (20, 255, 140)
GREY = (210, 210, 210)

SCREENWIDTH = 1000
SCREENHEIGHT = 578

IMG_WORKER_RUNNING = "images/workers/worker_1.png"
IMG_WORKER_IDLE = "images/workers/worker_2.png"
IMG_WORKER_ACCIDENT = "images/workers/accident.png"


class Worker(pygame.sprite.Sprite):
    RUNNING = 0
    IDLE = 1
    ACCIDENT = 2
    NUMBER_OF_ACCIDENTS = 0
    IMAGE_CACHE = {}

    def __init__(self, idw, image_running, image_idle, image_accident,
                 all_sprites, location, *groups):
        # Each state has it's own image
        self.images = {
            Worker.RUNNING: pygame.transform.scale(
                self.get_image(image_running),
                (45, 45)
            ),
            Worker.IDLE: pygame.transform.scale(
                self.get_image(image_idle),
                (20, 45)
            ),
            Worker.ACCIDENT: pygame.transform.scale(
                self.get_image(image_accident),
                (40, 40)
            )
        }

        self._layer = 2
        pygame.sprite.Sprite.__init__(self, groups)
        self.idw = idw
        self.reset(location)

    def reset(self, location):
        self.state = Worker.IDLE
        self.ticks_in_state = 0

        self.location = location
        self.image = self.images[self.state]
        self.rect = self.image.get_rect(topleft=location)

        self.direction = pygame.math.Vector2(0, 0)
        self.speed = random.randint(1, 3)

    def get_image(self, key):
        if not key in Worker.IMAGE_CACHE:
            Worker.IMAGE_CACHE[key] = pygame.image.load(key)
        return Worker.IMAGE_CACHE[key]


class Environment:
    def __init__(self, title):
        pygame.init()

        self.screen = pygame.display.set_mode((SCREENWIDTH, SCREENHEIGHT))
        pygame.display.set_caption(title)

        self.all_sprites = pygame.sprite.LayeredUpdates()
        self.workers = pygame.sprite.Group()
        self.fences = pygame.sprite.Group()

        # create a worker
        idw = 1
        Worker(idw, IMG_WORKER_RUNNING, IMG_WORKER_IDLE,
               IMG_WORKER_ACCIDENT, self.all_sprites, (50, 50), 
               self.workers)

    def run(self):
        carry_on = True
        clock = pygame.time.Clock()
        simulation_time = 10  # time in seconds

        while carry_on:
            for event in pygame.event.get():
                if (event.type == pygame.QUIT) or (simulation_time == 0):
                    carry_on = False
                    pygame.display.quit()
                    pygame.quit()
                    quit()

                simulation_time -= 1

            agent_action = 0
            send_alert = np.random.normal(0, 0.1, 1)

            if send_alert > 0.2:
                agent_action = 1

            self.all_sprites.update(self.screen, agent_action)
            self.all_sprites.draw(self.screen)

        pygame.display.flip()
        clock.tick(20)


if __name__ == "__main__":
    env = Environment("TEST")
    env.run()

推荐答案

您必须将 Worker.__init__ 方法中的 all_sprites 参数传递给 __init__Sprite 类的 方法，以便将精灵添加到该组中.

You have to pass the all_sprites argument in the Worker.__init__ method to the __init__ method of the Sprite class, so that the sprite will be added to this group.

pygame.sprite.Sprite.__init__(self, all_sprites, groups)

您还可以重新排列 __init__ 方法的参数并将这两个组作为最后一个参数传递(它们将被添加到 groups 列表中).

You could also rearrange the parameters of the __init__ method and pass the two groups as the last arguments (they will be added to the groups list).

# In the Worker class.
def __init__(self, idw, image_running, image_idle, image_accident,
             location, *groups):

# Pass the two groups as the `groups` argument.
Worker(idw, IMG_WORKER_RUNNING, IMG_WORKER_IDLE,
       IMG_WORKER_ACCIDENT, (50, 50), self.all_sprites, 
       self.workers)

在 while 循环中，您需要在每一帧中对背景表面进行 blit 或填充屏幕以清除它，然后绘制精灵，最后使用 pygame.display.flip() 更新屏幕(您需要在示例中缩进).

In the while loop you need to blit a background surface or fill the screen every frame in order to clear it, then draw the sprites and finally update the screen with pygame.display.flip() (you need to indent it in your example).

while carry_on:
    for event in pygame.event.get():
        if (event.type == pygame.QUIT) or (simulation_time == 0):
            carry_on = False
        # You probably don't want to decrement the
        # simulation_time once per event. Dedent
        # this line to decrement it once per frame.
        simulation_time -= 1

    agent_action = 0
    send_alert = np.random.normal(0, 0.1, 1)

    if send_alert > 0.2:
        agent_action = 1

    self.all_sprites.update(self.screen, agent_action)
    # Blit a background surface or fill the screen.
    self.screen.fill((0, 40, 0))  # Fill with dark green.
    # Blit all sprites.
    self.all_sprites.draw(self.screen)
    # Update the screen.
    pygame.display.flip()
    clock.tick(20)

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