using Godot;
using System;

/// <summary>
/// 测试地图层
/// </summary>
public partial class TestMap : TileMapLayer
{
	/// <summary>
	/// 上一次高亮的单元格。用于避免不必要的更新。
	/// </summary>
	private Vector2I _lastHighlightCell;
	private readonly Vector2I _highlightTileCoord = new(0, 5);
	private readonly Vector2I _vector2INegOne = new(-1, -1);
    
    // 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)
	{
		Vector2 mousePos = GetLocalMousePosition();
		Vector2I cell = LocalToMap(mousePos);

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