长风秋雁
由于pygame.Rect应该代表屏幕上的一个区域,一个pygame.Rect对象只能存储整数数据:Rect 对象的坐标都是整数。[...]如果要以浮点精度存储对象位置,则必须将对象的位置分别存储在单独的变量和属性中,并同步对象pygame.Rect。round坐标并将其分配给.topleft矩形的位置(例如):x, y = # floating point coordinates
rect.topleft = round(x), round(y)因此(x, y)是准确的位置并且(rect.x, rect.y)包含最接近该位置的整数。请参见以下示例。红色物体是通过直接改变物体的位置来移动的pygame.Rect,而绿色物体的位置存储在单独的属性中,移动是用浮点精度计算的。你可以清楚地看到红色物体在方向和速度方面的不准确:import pygameclass RedObject(pygame.sprite.Sprite): def __init__(self, p, t): super().__init__() self.image = pygame.Surface((20, 20), pygame.SRCALPHA) pygame.draw.circle(self.image, "red", (10, 10), 10) self.rect = self.image.get_rect(center = p) self.move = (pygame.math.Vector2(t) - p).normalize() def update(self, window_rect): self.rect.centerx += self.move.x * 2 self.rect.centery += self.move.y * 2 if not window_rect.colliderect(self.rect): self.kill()class GreenObject(pygame.sprite.Sprite): def __init__(self, p, t): super().__init__() self.image = pygame.Surface((20, 20), pygame.SRCALPHA) pygame.draw.circle(self.image, "green", (10, 10), 10) self.rect = self.image.get_rect(center = p) self.pos = pygame.math.Vector2(self.rect.center) self.move = (pygame.math.Vector2(t) - p).normalize() def update(self, window_rect): self.pos += self.move * 2 self.rect.center = round(self.pos.x), round(self.pos.y) if not window_rect.colliderect(self.rect): self.kill()pygame.init()window = pygame.display.set_mode((400, 400))clock = pygame.time.Clock()start_pos = (200, 200)all_sprites = pygame.sprite.Group()run = Truewhile run: clock.tick(100) for event in pygame.event.get(): if event.type == pygame.QUIT: run = False if event.type == pygame.MOUSEBUTTONDOWN: all_sprites.add(RedObject(start_pos, event.pos)) all_sprites.add(GreenObject(start_pos, event.pos)) all_sprites.update(window.get_rect()) window.fill(0) all_sprites.draw(window) pygame.draw.circle(window, "white", start_pos, 10) pygame.draw.line(window, "white", start_pos, pygame.mouse.get_pos()) pygame.display.flip()pygame.quit()exit()