feat(重构): 重构棋盘和棋子的逻辑

- 重构了 ChessBoard 和 ChessPiece 类的逻辑
- 添加了新版本的 ChineseChess 库
- 删除了旧版本的 VirtualBoard 和 VirtualPiece 类
- 更新了相关的场景和脚本

Scripts/Entities/ChessBoard.cs

@@ -1,38 +1,60 @@
 // Chessboard.cs
 using System;
 using Godot;
+using ChineseChess;
+using Godot.Collections;
 
 public partial class ChessBoard : Node2D {
     public event EventHandler<Vector2> OnMouseClicked;
 	public event EventHandler<Vector2> OnPosClicked;
 
+	public Vector2 from = Vector2.Inf, to = Vector2.Inf;
+	public Array<Vector2> canMovePos = new();
+
 	public override void _Ready() {
 	}
 
-	public void LoadBoard(VirtualBoard board) {
+	public void Clear() {
+		from = to = Vector2.Inf;
+		QueueRedraw();
+	}
+
+	public void LoadBoard(CCBoard board) {
 		board.OnRemove += (sender, piece) => {
-			if (piece.data != null) {
-				RemoveChild(piece.data as Node);
+			if (piece?.Data.TryGetValue("Godot", out object node) ?? false) {
+				RemoveChild(node as Node);
 			}
 		};
 
 		board.OnInsert += (sender, piece) => {
-			if (piece.data != null && piece.data is Node) {
-				AddChild(piece.data as Node);
+			ChessPiece chessPiece = null;
+			if (piece.Data.TryGetValue("Godot", out object node)) {
+				chessPiece = node as ChessPiece;
 			} else {
-				ChessPiece chessPiece = new(piece.name, piece);
-
-				if (piece.Pos().Y >= 5) {
-					chessPiece.LabelColor = new Color("red");
-				} else {
-					chessPiece.LabelColor = new Color("black");
-				}
-				AddChild(chessPiece);
+				chessPiece = new((CCPiece)piece);
 			}
+			chessPiece.ShowBehindParent = true;
+			AddChild(chessPiece);
+		};
+
+		board.OnMove += (sender, vals) => {
+			from = PosTrans.transArrToPix * new Vector2(vals.From.X, vals.From.Y);
+			to = PosTrans.transArrToPix * new Vector2(vals.To.X, vals.To.Y);
+			QueueRedraw();
 		};
 	}
-	
-	public override void _Input(InputEvent @event) {
+
+	public override void _Draw() {
+		Color color = new(0.7f, 0.7f, 0.7f, 0.5f);
+		DrawLine(from, to, color, PosTrans.pixGripSize / 5);
+		DrawCircle(from, PosTrans.pixGripSize / 2.2f, color);
+		foreach (Vector2 pos in canMovePos) {
+			DrawCircle(pos, PosTrans.pixGripSize / 2.2f,
+				 color.Inverted());
+		}
+    }
+
+    public override void _Input(InputEvent @event) {
 		if (@event is InputEventMouseButton mouseEvent &&
 				mouseEvent.Pressed &&
 				mouseEvent.ButtonIndex == MouseButton.Left) {
@@ -41,4 +63,13 @@ public partial class ChessBoard : Node2D {
 				GetLocalMousePosition()).Round());
 		}
 	}
+
+	public static class PosTrans {
+		public static readonly int pixGripSize = 32;
+		public static readonly Transform2D transArrToPix = new(
+			new Vector2(pixGripSize, 0),
+			new Vector2(0, pixGripSize),
+			new Vector2(-4, -4.5f) * pixGripSize
+		);
+	}
 }