如何只用左右两个键控制蛇

Question

目前，我正在使用所有四个键来向左、向右、向上和向下操纵蛇。我想知道如何只使用左右键来移动蛇。

                    if event.key == pygame.K_LEFT:
                        snake.direction = 2
                    elif event.key == pygame.K_RIGHT:
                        snake.direction = 3
                    elif event.key == pygame.K_UP:
                        snake.direction = 0
                    elif event.key == pygame.K_DOWN:
                        snake.direction = 1
    def move(self):
        if self.direction is 0:
            self.dy = -self.block
            self.dx = 0
        if self.direction is 1:
            self.dy = self.block
            self.dx = 0
        if self.direction is 2:
            self.dy = 0
            self.dx = -self.block
        if self.direction is 3:
            self.dy = 0
            self.dx = self.block
        self.x += self.dx
        self.y += self.dy

谁能指导我怎么做？

Answer 1

不是根据按键设置方向，而是让左右键通过增加或减少当前方向来调整方向。

我还更改了 move 函数，使方向按顺时针顺序排列。

                if event.key == pygame.K_LEFT:
                    snake.direction -= 1
                elif event.key == pygame.K_RIGHT:
                    snake.direction += 1

                if snake.direction > 3:
                    snake.direction = 0
                elif snake.direction < 0:
                    snake.direction = 3
def move(self):
    if self.direction is 0:
        self.dy = -self.block
        self.dx = 0
    if self.direction is 1:
        self.dy = 0
        self.dx = -self.block
    if self.direction is 2:
        self.dy = self.block
        self.dx = 0
    if self.direction is 3:
        self.dy = 0
        self.dx = self.block
    self.x += self.dx
    self.y += self.dy

Answer 2

                if event.key == pygame.K_LEFT:
                    if snake.direction == 0
                        snake.direction = 2
                    elif snake.direction == 2
                        snake.direction = 1
                    elif snake.direction == 1
                        snake.direction = 3
                    elif snake.direction == 3
                        snake.direction = 0
                elif event.key == pygame.K_RIGHT:
                    if snake.direction == 0
                        snake.direction = 3
                    elif snake.direction == 3
                        snake.direction = 1
                    elif snake.direction == 1
                        snake.direction = 2
                    elif snake.direction == 2
                        snake.direction = 0
def move(self):
    if self.direction is 0:
        self.dy = -self.block
        self.dx = 0
    if self.direction is 1:
        self.dy = self.block
        self.dx = 0
    if self.direction is 2:
        self.dy = 0
        self.dx = -self.block
    if self.direction is 3:
        self.dy = 0
        self.dx = self.block
    self.x += self.dx
    self.y += self.dy

这应该会根据它之前行进的方向旋转你的蛇。

Answer 3

定义方向如下：

0：向上移动
1：向右移动
2：下移
3：向右移动

def move(self):
    if self.direction is 0:
        self.dy = -self.block
        self.dx = 0
    if self.direction is 1:
        self.dy = 0
        self.dx = self.block
    if self.direction is 2:
        self.dy = 0
        self.dx = -self.block
    if self.direction is 3:
        self.dy = self.block
        self.dx = 0

    self.x += self.dx
    self.y += self.dy

当按下 right 时，snake.direction 加 1，当按下 left 时，减 1。使用 %（取模）运算符（参见 Binary arithmetic operations）以确保结果在 [0, 3]:

范围内

if event.key == pygame.K_LEFT:
    snake.direction = (snake.direction - 1) % 4
if event.key == pygame.K_RIGHT:
    snake.direction = (snake.direction + 1) % 4

如何只用左右两个键控制蛇

how to control snake with only two keys i.e left and right

python

pygame

game-physics