yep

Shogi.Domain/Other/MoveValidationContext.cs

@@ -0,0 +1,14 @@
+namespace Shogi.Domain.Other;
+
+public record MoveValidationContext<TPiece>(
+	Vector2 From,
+	Vector2 To,
+	bool IsPromotion,
+	TPiece?[,] BoardState) where TPiece : IRulesLifecycle<TPiece>
+{
+	public TPiece? GetPieceByRelativePosition(Vector2 relativePosition)
+	{
+		var absolute = From + relativePosition;
+		return BoardState[(int)absolute.X, (int)absolute.Y];
+	}
+}