using Godot;

/// <summary>
///     测试地图层
/// </summary>
public partial class TestMap : TileMapLayer {
    private readonly Vector2I _highlightTileCoord = new(0, 5);
    private readonly Vector2I _vector2INegOne = new(-1, -1);

    /// <summary>
    ///     上一次高亮的单元格。用于避免不必要的更新。
    /// </summary>
    private Vector2I _lastHighlightCell;

    // Called when the node enters the scene tree for the first time.
    /// <summary>
    ///     场景加载完成时调用
    /// </summary>
    public override void _Ready() {
        // 初始化最后高亮单元格为无效值。
        _lastHighlightCell = _vector2INegOne;
    }

    /// <summary>
    ///     每帧更新。
    /// </summary>
    /// <param name="delta">距离上一帧的时间间隔。</param>
    public override void _Process(double delta) {
        var mousePos = GetLocalMousePosition();
        var cell = LocalToMap(mousePos);

        if (cell != _lastHighlightCell) {
            if (_lastHighlightCell != _vector2INegOne) EraseCell(_lastHighlightCell);
            _lastHighlightCell = cell;
            SetCell(cell, 0, _highlightTileCoord);
        }
    }
}