我实际上发布了一个类似的问题，但没有任何不工作的代码。 现在我有了一些。 所以我想让snake向一个方向移动（例如:向上），直到我按下另一个按钮（向下，向左，向右），我会改变方向。
然而，我在这段代码中注释掉了其中一个问题，但现在它只以这种方式部分工作:
如果我往上压，我只能再往下压一次，它就会永远移动，如果我往左压或往右压，我只能往上压或往下压，然后交替地往下压或往上压，它就会永远朝那个方向移动
下面是代码:
void Game::ProcessEvents(){
sf::Event event;
while (myWindow.pollEvent(event)){
switch(event.type){
case sf::Event::KeyPressed : handlePlayerInput(event.key.code, true); break;
//case sf::Event::KeyReleased : handlePlayerInput(event.key.code, false); break;
case sf::Event::Closed : myWindow.close(); break;
}
}
}
void Game::handlePlayerInput(sf::Keyboard::Key key, bool isPressed){
if (key == sf::Keyboard::W || key == sf::Keyboard::Up) movingUp = isPressed;
else if (key == sf::Keyboard::S || key == sf::Keyboard::Down) movingDown = isPressed;
else if (key == sf::Keyboard::A || key == sf::Keyboard::Left) movingLeft = isPressed;
else if (key == sf::Keyboard::D || key == sf::Keyboard::Right) movingRight = isPressed;
}
void Game::update(){
sf::Vector2f movement(0.0f, 0.0f);
if (movingUp) { movingLeft = false; movingRight = false; movingDown = false; movement.y -= 0.1f;}
if (movingDown) { movingUp = false; movingLeft = false; movingRight = false; movement.y += 0.1f; }
if (movingLeft) { movingRight = false; movingUp = false; movingDown = false; movement.x -= 0.1f; }
if (movingRight) { movingLeft = false; movingDown = false; movingUp = false; movement.x += 0.1f; }
isColliding(movement);
}
我并不是最喜欢读取输入，然后将其转换为movation对象的人。 例如，如果MovingUp为true，何时将其设置为false？ 答案是永远不会！ 那是不可能发生的！
相反，我用一个单个变量创建一个枚举来表示当前的移动方向:
enum Dir { RIGHT, LEFT, UP, DOWN };
Dir curr_dir = RIGHT; // Start the game moving right
现在您的HandlePlayerInput逻辑可能如下所示:
if (key == sf::Keyboard::W || key == sf::Keyboard::Up) curr_dir = UP;
else if (key == sf::Keyboard::S || key == sf::Keyboard::Down) curr_dir = DOWN;
else if (key == sf::Keyboard::A || key == sf::Keyboard::Left) curr_dir = LEFT;
else if (key == sf::Keyboard::D || key == sf::Keyboard::Right) curr_dir = RIGHT;
更新逻辑现在可以是:
switch(curr_dir) {
case UP:
movement.y -= 0.1f;
break;
case DOWN:
movement.y += 0.1f;
break;
case RIGHT:
movement.x -= 0.1f;
break;
case LEFT:
movement.x += 0.1f;
break;
}
我会这样做:
enum class Dir { up, down, left, right };
void Game::handlePlayerInput(sf::Keyboard::Key key, bool isPressed){
if (key == sf::Keyboard::W || key == sf::Keyboard::Up) direction = Dir::up;
else if (key == sf::Keyboard::S || key == sf::Keyboard::Down) direction = Dir::down;
else if (key == sf::Keyboard::A || key == sf::Keyboard::Left) direction = Dir::left;
else if (key == sf::Keyboard::D || key == sf::Keyboard::Right) direction = Dir::right;
void Game::update(){
sf::Vector2f movement(0.0f, 0.0f);
if (direction == Dir::up) movement.y -= 0.1f;
else if (direction == Dir::down) movement += 0.1f;
else if (direction == Dir::left) movement.x -= 0.1f;
else if (direction == Dir::right) movement += 0.1f;
isColliding(movement);
