Python/Pygame精灵图像和遮罩在向前或向后移动时更新，但在旋转时不更新

Question

以下代码尝试；将一个小图形与其遮罩一起移动，但没有成功。当键盘输入指示向前和向后时，图形(car.png(按预期移动。但是，当键盘输入指示旋转时，汽车图形将消失，并显示占位符三角形。占位符三角形随后的行为与汽车图形(及其遮罩(的行为相同。

import math
import pygame as pg
from pygame.math import Vector2

class Player(pg.sprite.Sprite):
def __init__(self, pos=(420, 420)):
super(Player, self).__init__()
self.image = pg.Surface((70, 50), pg.SRCALPHA)
pg.draw.polygon(self.image, (50, 120, 180), ((0, 0), (0, 50), (70, 25)))
self.original_image = self.image
self.rect = self.image.get_rect(center=pos)
# Instead we could load a picture of a car
self.image = pg.image.load("car.png").convert_alpha()
self.mask = pg.mask.from_surface(self.image)
self.position = Vector2(pos)
self.direction = Vector2(1, 0)  # A unit vector pointing rightward.
self.speed = 2
self.angle_speed = 0
self.angle = 0
def update(self):
if self.angle_speed != 0:
# Rotate the direction vector and then the image.
self.direction.rotate_ip(self.angle_speed)
self.angle += self.angle_speed
self.image = pg.transform.rotate(self.original_image, -self.angle)
self.rect = self.image.get_rect(center=self.rect.center)
# Update the position vector and the rect.
self.position += self.direction * self.speed
self.rect.center = self.position

def main():
pg.init()
screen = pg.display.set_mode((1280, 720))
player = Player((420, 420))
playersprite = pg.sprite.RenderPlain((player))
clock = pg.time.Clock()
done = False
while not done:
clock.tick(60)
for event in pg.event.get():
if event.type == pg.QUIT:
done = True
elif event.type == pg.KEYDOWN:
if event.key == pg.K_UP:
player.speed += 1
elif event.key == pg.K_DOWN:
player.speed -= 1
elif event.key == pg.K_LEFT:
player.angle_speed = -4
elif event.key == pg.K_RIGHT:
player.angle_speed = 4
elif event.type == pg.KEYUP:
if event.key == pg.K_LEFT:
player.angle_speed = 0
elif event.key == pg.K_RIGHT:
player.angle_speed = 0
playersprite.update()
screen.fill((30, 30, 30))
playersprite.draw(screen)
pg.display.flip()
if __name__ == '__main__':
main()
pg.quit()

Answer 1

请参阅如何使用PyGame围绕图像中心旋转图像？。你根本不需要三角形。original_image需要成为汽车：

class Player(pg.sprite.Sprite):
def __init__(self, pos=(420, 420)):
super(Player, self).__init__()

self.original_image = pg.image.load("car.png").convert_alpha()
self.image = self.original_image
self.rect = self.image.get_rect(center=pos)
self.mask = pg.mask.from_surface(self.image)
self.position = Vector2(pos)
self.direction = Vector2(1, 0)  # A unit vector pointing rightward.
self.speed = 2
self.angle_speed = 0
self.angle = 0