如何阻止精灵使用Pygame对角移动？

Question

我正在制作蛇游戏。每当我按箭头键向一个方向移动然后按另一个方向的键，蛇就会对角线。 （例如，如果我先按下然后按下。）即使释放了上一个键，也会发生这种情况。我怎么能阻止这个？

# x and y marks the player's position

if event.type == pygame.KEYDOWN:
    if event.key == pygame.K_LEFT:
        x_change = -10
    if event.key == pygame.K_RIGHT:
        x_change = 10
    if event.key == pygame.K_UP:
        y_change = -10
    if event.key == pygame.K_DOWN:
        y_change = 10
    x += x_change
    y += y_change

Answer 1

我添加了y_change = 0和x_change = 0来重置值以仅保持正交移动。

if event.type == pygame.KEYDOWN:
    if event.key == pygame.K_LEFT:
        x_change = -10
        y_change = 0
    if event.key == pygame.K_RIGHT:
        x_change = 10
        y_change = 0
    if event.key == pygame.K_UP:
        y_change = -10
        x_change = 0
    if event.key == pygame.K_DOWN:
        y_change = 10
        x_change = 0
    x += x_change
    y += y_change