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[英]Pygame/Python For loop only blitting last element inside sprite list
[英]Python/Pygame: loop over a copy of Sprite list
我正在嘗試使用下面的代碼創建雨滴流以給人一種下雨的感覺。 雨滴用於對雨滴進行建模。 它有一個 update method() 來增加 y 坐標,這樣當我調用這個方法時它看起來就像是在屏幕上。
from pygame.sprite import Sprite
class Raindrop(Sprite):
"""A class to represent a single raindrop."""
def __init__(self, rain_game):
"""Initialize the raindrop and set its starting position."""
super().__init__()
self.screen = rain_game.screen
self.settings = rain_game.settings
# Load the raindrop image and set its rect attribute
self.image = pygame.image.load('raindrop.bmp')
self.rect = self.image.get_rect()
#Start each raindrop near the top left of the screen.
self.rect.x = self.rect.width
self.rect.y = self.rect.height
#Store the raindrop`s exact horizontal and vertical positions.
self.x = self.rect.x
self.y = self.rect.y
def update(self):
"""Shift raindrops to one level below"""
self.y += self.settings.rain_speed
self.rect.y = self.y
class Settings:
"""A Class to store all settings for a Sky Full of Stars."""
def __init__(self):
"""Initialize the game`s settings."""
# Screen setiings
self.screen_width = 1200
self.screen_height = 800
self.bg_color = (255, 255, 255)
self.rain_speed = 1.0
下面代碼中的 remove_add_raindrops 方法有問題。 它按預期工作,但僅適用於我筆記本電腦中的 4 行雨滴。 4 行后,此代碼停止將任何雨滴打印到屏幕上。 所以我只看到 8 行雨滴從屏幕的頂部滴到底部。
import sys
import pygame
from settings import Settings
from raindrop import Raindrop
class Raining():
"""Overall class to display a sky with raindrops."""
def __init__(self):
"""Initialize the game, and create game resources."""
pygame.init()
self.settings = Settings()
self.screen = pygame.display.set_mode((0, 0), pygame.FULLSCREEN)
self.settings.screen_width = self.screen.get_rect().width
self.settings.screen_height = self.screen.get_rect().height
pygame.display.set_caption("It is raining today")
self.raindrops = pygame.sprite.Group()
self._create_raindrops()
def _create_raindrop(self, raindrop_number, row_number):
"""Create a raindrop and place it in the row."""
raindrop = Raindrop(self)
raindrop_width, raindrop_height = raindrop.rect.size
raindrop.x = raindrop_width + 2 * raindrop_width * raindrop_number
raindrop.rect.x = raindrop.x
raindrop.y = raindrop_height + 2 * raindrop_height * row_number
raindrop.rect.y = raindrop.y
self.raindrops.add(raindrop)
def _create_raindrops(self):
"""Create a full screen fo raindrops."""
# Create a raindrop and find the number of raindrops in a row.
# Spacing between each raindrop is equal to one raindrop width.
raindrop = Raindrop(self)
raindrop_width, raindrop_height = raindrop.rect.size
available_space_x = self.settings.screen_width - (2 * raindrop_width)
number_raindrops_x = available_space_x // (2 * raindrop_width)
# Determine the number of rows of raindrops that fit on the screen.
available_space_y = (self.settings.screen_height - 2 * raindrop_height)
number_rows = available_space_y // (2 * raindrop_height)
# Create a full screen of raindrops.
for row_number in range(number_rows):
for raindrop_number in range (number_raindrops_x):
self._create_raindrop(raindrop_number, row_number)
def _remove_add_raindrops(self):
"""
Get rid of old raindrops.
Then update their y coordinate and append to the raindrops sprite group
"""
for raindrop in self.raindrops.copy():
if raindrop.rect.y >= self.settings.screen_height:
self.raindrops.remove(raindrop)
raindrop.rect.y -= self.settings.screen_height
self.raindrops.add(raindrop)
def run_game(self):
"""Start the main loop for the game."""
while True:
self._check_events()
self._update_raindrops()
self._remove_add_raindrops()
self._update_screen()
print(f"Nr of remaining raindrops: {len(self.raindrops)}")
#Make the most recently drawn screen visible.
pygame.display.flip()
def _check_events(self):
"""Respond to keypresses and mouse events."""
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys-exit()
elif event.type == pygame.KEYDOWN:
self._check_keydown_events(event)
def _check_keydown_events(self, event):
"""Respond to keypresses."""
if event.key == pygame.K_q:
sys.exit()
def _update_raindrops(self):
"""Update the positions of all raindrops."""
self.raindrops.update()
def _update_screen(self):
"""Update images on the screen, and flip to the new screen."""
self.screen.fill(self.settings.bg_color)
self.raindrops.draw(self.screen)
if __name__ == '__main__':
# Make a game instance, and run the game.
rain_game = Raining()
rain_game.run_game()
我還打印了列表中的雨滴數量,它始終固定為 40。我想這意味着在刪除滑到屏幕下方的雨滴后,我會繼續添加具有新 y 坐標的新雨滴。
任何提示?
更新:
我去掉了_remove_add_raindrops方法,在raindrop類下重新寫了update方法如下:
def update(self):
"""Shift raindrops to one level below"""
self.y += self.settings.rain_speed
self.rect.y = self.y
if self.rect.top >= self.screen.get_rect().bottom:
self.rect.y -= self.settings.screen_height
它仍然是相同的行為。
_remove_add_raindrops
運行
raindrop.rect.y -= self.settings.screen_height
改變雨滴的rect
的y
屬性。
但是當調用Raindrop
的update
函數時,該更改會立即被覆蓋:
def update(self):
"""Shift raindrops to one level below"""
self.y += self.settings.rain_speed
self.rect.y = self.y
因為它再次更改為self.y
。
只需刪除_remove_add_raindrops
(刪除並立即將Raindrop
self.raindrops
到self.raindrops
沒有任何意義)並更改您的Raindrop
類如下:
class Raindrop(Sprite):
"""A class to represent a single raindrop."""
def __init__(self, rain_game):
"""Initialize the raindrop and set its starting position."""
super().__init__()
self.screen = rain_game.screen
self.settings = rain_game.settings
# Load the raindrop image and set its rect attribute
self.image = pygame.image.load('raindrop.bmp')
self.rect = self.image.get_rect()
#Start each raindrop near the top left of the screen.
self.rect.x = self.rect.width
self.rect.y = self.rect.height
def update(self):
"""Shift raindrops to one level below"""
self.rect.move_ip(0, self.settings.rain_speed)
if not pygame.display.get_surface().get_rect().bottom > self.rect.top:
self.rect.bottom = 0
所以Raindrop
類可以檢查自己是否離開屏幕。 如果您想使用浮點數而不是整數來存儲Sprite
的位置,我建議使用Vector2
類來這樣做,而不是使用單個屬性,因為從長遠來看,這樣可以更容易地對角移動您的精靈。
問題是 self.y 無限增加,因為我沒有在原始代碼或更新后的代碼中的任何地方重新設置它。
def update(self):
"""Shift raindrops to one level below"""
self.y += self.settings.rain_speed
self.rect.y = self.y
if self.rect.top >= self.screen.get_rect().bottom:
self.rect.y -= self.settings.screen_height
將上面最后一行從“self.rect.y”更改為“self.y”解決了問題。
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