Unity2D推箱游戏网格系统对象重叠问题求助

我在Unity2D开发推箱游戏时，需要实现玩家推动方块时，方块不能和已被其他方块占据的格子重叠，但当前代码始终无法实现该功能，以下是关键代码片段：

MovableObject脚本 #

public class MovableObject : MonoBehaviour
{
private GridManager _gridManager;    
public float currentX;
public float currentY;

void MoveToRightTile(Transform protagonistTransform)
{          
    Debug.Log("Right");
    float newX = transform.position.x + _gridManager._tileSize;
    float newY = transform.position.y;

    int targetGridX = _gridManager.GetGridX(newX);
    int targetGridY = _gridManager.GetGridY(newY);
    
    if(_gridManager.MinX < newX && newX < _gridManager.MaxX)
    {
        IsWithinGridBounds = true;
    }
    else
    {
        IsWithinGridBounds = false;
    }

    if (IsWithinGridBounds && canMove && !_gridManager.IsTileOccupied(targetGridX, targetGridY))
    {
        Vector2 newPosition = new Vector2(newX, newY);
        transform.position = newPosition;

        // Update the grid position in the GridManager
        _gridManager.MoveGameObjectTo(this, _gridManager.GetGridX(newX), _gridManager.GetGridY(newY));
        newX = currentX;
        newY = currentY;
    }
}

GridManager脚本 #

public class GridManager : MonoBehaviour
{
[SerializeField] private int _width, _height;
[SerializeField] private Tile _tilePrefab;
[SerializeField] private GameObject _gameObjectPrefab;


private GameObject[,] _gameObjects;

    public void RegisterObjectAt(MovableObject movableObject, int x, int y)
{
    _gameObjects[x, y] = movableObject.gameObject;
}
public bool IsTileOccupied(int x, int y)
{
    // Check if the specified tile is occupied
    return _gameObjects[x, y] != null;
}
 public void MoveGameObjectTo(MovableObject movableObject, int x, int y)
{
    int currentX = GetGridX(movableObject.transform.position.x);
    int currentY = GetGridY(movableObject.transform.position.y);

    // Check if the destination is valid (within grid bounds and unoccupied)
    if (x >= 0 && x < _width && y >= 0 && y < _height && _gameObjects[x, y] == null)
    {
        // Clear the current grid position
        _gameObjects[currentX, currentY] = null;

        MarkTileUnoccupied(currentX, currentY);
        // Update the grid position
        movableObject.UpdateGridPosition();

    }
}

public void MarkTileUnoccupied(int x, int y)
{
    _gameObjects[x, y] = null;
}

问题分析 #

1. GridManager核心逻辑缺失：MoveGameObjectTo方法只清空了方块的原网格位置，但未将方块注册到目标网格位置，导致_gameObjects[x,y]始终为null，IsTileOccupied无法正确判断目标格子状态。
2. MovableObject位置更新错误：newX = currentX; newY = currentY;是将旧值覆盖新变量，应该反过来把新位置赋值给currentX和currentY，否则对象的当前位置记录完全错误。
3. 冗余计算与边界判断不严谨：MoveToRightTile中调用MoveGameObjectTo时重复计算网格索引，且仅通过世界坐标判断边界，未验证网格索引是否在有效范围内，可能触发数组越界。
4. 重复执行清空操作：_gameObjects[currentX, currentY] = null;和MarkTileUnoccupied(currentX, currentY);功能完全重复，无需执行两次。

修复后的代码 #

修改MovableObject的MoveToRightTile方法

void MoveToRightTile(Transform protagonistTransform)
{          
    Debug.Log("Right");
    float newX = transform.position.x + _gridManager._tileSize;
    float newY = transform.position.y;

    int targetGridX = _gridManager.GetGridX(newX);
    int targetGridY = _gridManager.GetGridY(newY);
    
    // 通过网格索引直接判断边界，更准确可靠
    IsWithinGridBounds = targetGridX >= 0 && targetGridX < _gridManager._width && 
                         targetGridY >= 0 && targetGridY < _gridManager._height;

    if (IsWithinGridBounds && canMove && !_gridManager.IsTileOccupied(targetGridX, targetGridY))
    {
        Vector2 newPosition = new Vector2(newX, newY);
        transform.position = newPosition;

        // 使用已计算的网格索引，避免重复计算
        _gridManager.MoveGameObjectTo(this, targetGridX, targetGridY);
        // 正确更新对象记录的当前位置
        currentX = newX;
        currentY = newY;
    }
}

修改GridManager的MoveGameObjectTo方法

public void MoveGameObjectTo(MovableObject movableObject, int x, int y)
{
    int currentX = GetGridX(movableObject.transform.position.x);
    int currentY = GetGridY(movableObject.transform.position.y);

    if (x >= 0 && x < _width && y >= 0 && y < _height && _gameObjects[x, y] == null)
    {
        // 清空原网格位置
        _gameObjects[currentX, currentY] = null;
        // 关键步骤：将对象注册到目标网格位置
        _gameObjects[x, y] = movableObject.gameObject;
        // 更新对象自身的网格位置记录
        movableObject.UpdateGridPosition();
    }
}

额外注意事项 #

• 确保GridManager初始化时已创建_gameObjects数组，例如在Awake方法中执行_gameObjects = new GameObject[_width, _height];，否则会触发空引用异常。
• 验证GetGridX和GetGridY方法的坐标转换逻辑是否正确，这是网格判断的基础，转换错误会导致所有格子状态判断失效。

内容的提问来源于stack exchange，提问作者Mr. Slime