如何在 SFML 中实现基于网格的移动？

Question

我无法在 SFML 中获得良好的基于 32x32 网格的运动，需要一些帮助来弄清楚如何使其工作。这是我到目前为止得到的：

void player::updateMovement()
{
if(walkFinish) {
    pixelWalked = 0;
    if(sf::Keyboard::isKeyPressed(sf::Keyboard::Up)) {
        direction = 1; // direction set to up

        EndYPos = GetPosition().y - 32; // The position the character is moving towards.

        walkFinish = false;
    } else if(sf::Keyboard::isKeyPressed(sf::Keyboard::Right) && canMoveRight) {
        direction = 2; // Right

        EndXPos = GetPosition().x + 32;

        walkFinish = false;
    } else if(sf::Keyboard::isKeyPressed(sf::Keyboard::Down)) {
        direction = 3; // Down

        EndYPos = GetPosition().y + 32;

        walkFinish = false;
    } else if(sf::Keyboard::isKeyPressed(sf::Keyboard::Left)) {
        direction = 4; // Left

        EndXPos = GetPosition().x - 32;

        walkFinish = false;
    }
} else if(!walkFinish && direction > 0 && direction < 5) { // if walk is not finished, move character.
    if(direction == 1 && !(EndYPos == GetPosition().y)){ // Up
        rect.move(0, -movementSpeed);

    } else if(direction == 2 && !(EndXPos == GetPosition().x) && canMoveRight) { // Right
        rect.move(movementSpeed, 0);

    } else if(direction == 3 && !(EndYPos == GetPosition().y)) { // Down
        rect.move(0, movementSpeed);

    } else if(direction == 4 && !(EndXPos == GetPosition().x)) { // Left
        rect.move(-movementSpeed, 0);
    }
}

if( ((EndXPos == GetPosition().x) && (EndYPos == GetPosition().y)) && !(sf::Keyboard::isKeyPressed(sf::Keyboard::Up)) && !(sf::Keyboard::isKeyPressed(sf::Keyboard::Right)) && !(sf::Keyboard::isKeyPressed(sf::Keyboard::Down)) && !(sf::Keyboard::isKeyPressed(sf::Keyboard::Left)) ) {
    walkFinish = true; // if character has reached endpos in both axis, walkFinish becomes true
} else if( ((EndXPos == GetPosition().x) && (EndYPos == GetPosition().y))) { // This gets rid of a 1 frame character pause and makes the movement smoother
    if(sf::Keyboard::isKeyPressed(sf::Keyboard::Up)) {
        direction = 1; // direction set to up
        EndYPos = GetPosition().y - 32; // Same deal as the first if statement of this function.
    } else if(sf::Keyboard::isKeyPressed(sf::Keyboard::Right) && canMoveRight) {
        direction = 2;
        EndXPos = GetPosition().x + 32;

    } else if(sf::Keyboard::isKeyPressed(sf::Keyboard::Down)) {
        direction = 3;
        EndYPos = GetPosition().y + 32;

    } else if(sf::Keyboard::isKeyPressed(sf::Keyboard::Left)) {
        direction = 4;
        EndXPos = GetPosition().x - 32;

    }

}
}

我的碰撞检查：

counter = 0;
for(iterWall = wallArray.begin(); iterWall != wallArray.end(); iterWall++) {
    if(objectPlayer.rect.getPosition().x == (wallArray[counter].rect.getPosition().x + 64)) {
        objectPlayer.canMoveLeft = false;
    } else if(objectPlayer.rect.getPosition().x == (wallArray[counter].rect.getPosition().x - 64)) {
        objectPlayer.canMoveRight = false;
    } else if(objectPlayer.rect.getPosition().y == (wallArray[counter].rect.getPosition().y - 64)) {
        objectPlayer.canMoveDown = false;
    } else if(objectPlayer.rect.getPosition().y == (wallArray[counter].rect.getPosition().y + 64)) {
        objectPlayer.canMoveUp = false;
    } else {
        objectPlayer.canMoveUp = true;
        objectPlayer.canMoveRight = true;
        objectPlayer.canMoveDown = true;
        objectPlayer.canMoveLeft = true;
    }

    counter++;
}

此代码的问题在于碰撞部分，因为角色在与墙壁碰撞时有被卡住的风险。碰撞甚至发生在墙上方，因此我的角色无法移动到那里。我不知道如何实现基于网格的移动和碰撞，谁有示例代码、博客-post、教程或一些提示？

编辑：碰撞部分发生在 updateMovement 函数之前！

Answer 1

我不知道你是否这样做，但通常你可以在应用它之前检查注册的移动（或者如果需要的话稍后再执行移动和撤消）然后检查它是否与墙壁碰撞以及它是否只是忽略输入移动。或者您可以在检测到碰撞后应用非常小的边距，这样如果不再次推动它就不会再次碰撞。

Answer 2

终于弄明白了：

counter = 0;
    for(iterWall = wallArray.begin(); iterWall != wallArray.end(); iterWall++) {
        if(!leftCheck){
            if( ( (wallArray[counter].rect.getPosition().x + 64) == objectPlayer.rect.getPosition().x ) && ( (wallArray[counter].rect.getPosition().y) == objectPlayer.rect.getPosition().y ) ) {
                objectPlayer.canMoveLeft = false; // if character is standing directly to the right of player AND(wall and player is at the same height), player cant move left.
                leftCheck = true;
            } else {
                objectPlayer.canMoveLeft = true;
            }
        }

        if(!rightCheck) {
            if( ( (wallArray[counter].rect.getPosition().x + - 64) == objectPlayer.rect.getPosition().x ) && ( (wallArray[counter].rect.getPosition().y) == objectPlayer.rect.getPosition().y ) ) {
                objectPlayer.canMoveRight = false;
                rightCheck = true;
            } else {
                objectPlayer.canMoveRight = true;
            }
        }

        if(!downCheck) {
            if( ( (wallArray[counter].rect.getPosition().y + 64) == objectPlayer.rect.getPosition().y ) && ( wallArray[counter].rect.getPosition().x == objectPlayer.rect.getPosition().x ) ) {
                objectPlayer.canMoveUp = false;
                downCheck = true;
            } else {
                objectPlayer.canMoveUp = true;
            }
        }

        if(!upCheck) {
            if( ( (wallArray[counter].rect.getPosition().y - 64) == objectPlayer.rect.getPosition().y ) && ( wallArray[counter].rect.getPosition().x == objectPlayer.rect.getPosition().x ) ) {
                objectPlayer.canMoveDown = false;
                upCheck = true;
            } else {
                objectPlayer.canMoveDown = true;
            }
        }

        counter++;
    }
    upCheck = false;
    rightCheck = false;
    downCheck = false;
    leftCheck = false;

当我在游戏中添加更多墙时，我意识到下一堵墙覆盖了之前的墙 canMoveUp 布尔值变化。为了防止这种变化，我在代码中添加了一些检查，如上所示。这些检查在游戏启动时添加一次，但除了此处之外，代码中的其他任何地方都没有更改。

我的 updateMovement 一分为二以防止帧暂停：

void player::updateEndPos() {
    if( (EndXPos == GetPosition().x) && (EndYPos == GetPosition().y) ) {
        if(canMoveUp && sf::Keyboard::isKeyPressed(sf::Keyboard::Up)) {
            direction = 1; // direction set to Up

            EndYPos = GetPosition().y - 64; // Sets end-pos so the character knows where to stop.

        } else if(canMoveRight && sf::Keyboard::isKeyPressed(sf::Keyboard::Right)) {
        direction = 2; // direction set to Right

            EndXPos = GetPosition().x + 64;

        } else if(canMoveDown && sf::Keyboard::isKeyPressed(sf::Keyboard::Down)) {
            direction = 3; // direction set to Down

        EndYPos = GetPosition().y + 64;

        } else if(canMoveLeft && sf::Keyboard::isKeyPressed(sf::Keyboard::Left)) {
            direction = 4; // direction set to Left

            EndXPos = GetPosition().x - 64;

        }
    }
}

以及：

void player::updateMovement() {
    if(EndYPos != GetPosition().y) {
        if(direction == 1) {
            rect.move(0, -movementSpeed); // moves player at "movementSpeed" speed.
        } else if(direction == 3) {
                rect.move(0, movementSpeed);
        } else {
            std::cout << "ERROR IN Y AXIS" << std::endl;
        }
        } else if(EndXPos != GetPosition().x) {
            if(direction == 2) {
                rect.move(movementSpeed, 0);
        } else if(direction == 4) {
            rect.move(-movementSpeed, 0);
        } else {
            std::cout << "ERROR IN X AXIS" << std::endl;
        }
    }
}

首先我检查碰撞，然后执行 updateEndPos()，然后直接执行 updateMovement()。

我将 updateEndPos 和 updateMovement 分开，因为如果我不这样做，我会得到一个帧，其中 updateEndPos() 部分不会执行，玩家会在该帧中静止不动。它非常明显，但已修复它，现在角色的移动看起来很流畅。

如何在 SFML 中实现基于网格的移动？

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