SebLague
UndoMove sometimes results in IndexOutOfRangeException when a pawn captures
Update to latest version as there has been many improvements regarding the board and movement
I can reproduce it with my bot, who plays c4 as white first and than by personally laying d5
i couldn't seem to reproduce it even with this code i wrote: public Move Think(Board board, Timer timer) { Move[] moves = board.GetLegalMoves(); int score = 0;
// play Pawn C4
for (int i = 0; i < moves.Length; i++)
{
Move move = moves[i];
if (move.TargetSquare.ToString().Contains("c4"))
{
return move;
}
else
{
score = Minimax(board, 3, int.MinValue, int.MaxValue);
Console.WriteLine(score);
}
}
return moves[0];
}
it would play c4, then i'd play d5 and it would eval and then it would just continue
the error is caused by making the bot move c4d5 using MakeMove() and then undo that with UndoMove(), maybe UndoMove just can't be used when a pawn takes a double dashed pawn
@Ben10Gh Are you sure the move is legal? Did you get the move from the list obtained in Board.getLegalMoves() or are you generating the moves manually?
Pulled yesterday and I'm able to get it.
An error occurred while bot was thinking.
System.IndexOutOfRangeException: Index was outside the bounds of the array.
at ChessChallenge.Chess.PieceList.AddPieceAtSquare(Int32 square) in C:\Users\Jonat\Desktop\chess\Chess-Challenge\Chess-Challenge\src\Framework\Chess\Board\PieceList.cs:line 29
at ChessChallenge.Chess.Board.UndoMove(Move move, Boolean inSearch) in C:\Users\Jonat\Desktop\chess\Chess-Challenge\Chess-Challenge\src\Framework\Chess\Board\Board.cs:line 345
at ChessChallenge.API.Board.UndoMove(Move move) in C:\Users\Jonat\Desktop\chess\Chess-Challenge\Chess-Challenge\src\API\Board.cs:line 98
at MyBot.minimax(Boolean max, Int32 currentDepth, Int32 maxDepth) in C:\Users\Jonat\Desktop\chess\Chess-Challenge\Chess-Challenge\src\My Bot\MyBot.cs:line 107
at MyBot.Think(Board board, Timer timer) in C:\Users\Jonat\Desktop\chess\Chess-Challenge\Chess-Challenge\src\My Bot\MyBot.cs:line 135
at ChessChallenge.Application.ChallengeController.GetBotMove() in C:\Users\Jonat\Desktop\chess\Chess-Challenge\Chess-Challenge\src\Framework\Application\Core\ChallengeController.cs:line 150
Illegal move: Null in position: r4rk1/4ppbp/p1qp1Qp1/1p6/3BP3/2P4P/PP1N1PP1/R4RK1 b - - 0 16
Game Over: BlackIllegalMove
Unhandled exception. System.IndexOutOfRangeException: Index was outside the bounds of the array.
at ChessChallenge.Chess.PieceList.AddPieceAtSquare(Int32 square) in C:\Users\Jonat\Desktop\chess\Chess-Challenge\Chess-Challenge\src\Framework\Chess\Board\PieceList.cs:line 29
at ChessChallenge.Chess.Board.UndoMove(Move move, Boolean inSearch) in C:\Users\Jonat\Desktop\chess\Chess-Challenge\Chess-Challenge\src\Framework\Chess\Board\Board.cs:line 345
at ChessChallenge.API.Board.UndoMove(Move move) in C:\Users\Jonat\Desktop\chess\Chess-Challenge\Chess-Challenge\src\API\Board.cs:line 98
at MyBot.minimax(Boolean max, Int32 currentDepth, Int32 maxDepth) in C:\Users\Jonat\Desktop\chess\Chess-Challenge\Chess-Challenge\src\My Bot\MyBot.cs:line 107
at MyBot.Think(Board board, Timer timer) in C:\Users\Jonat\Desktop\chess\Chess-Challenge\Chess-Challenge\src\My Bot\MyBot.cs:line 135
at ChessChallenge.Application.ChallengeController.GetBotMove() in C:\Users\Jonat\Desktop\chess\Chess-Challenge\Chess-Challenge\src\Framework\Application\Core\ChallengeController.cs:line 150
--- End of stack trace from previous location ---
at ChessChallenge.Application.ChallengeController.Update() in C:\Users\Jonat\Desktop\chess\Chess-Challenge\Chess-Challenge\src\Framework\Application\Core\ChallengeController.cs:line 378
at ChessChallenge.Application.Program.Main() in C:\Users\Jonat\Desktop\chess\Chess-Challenge\Chess-Challenge\src\Framework\Application\Core\Program.cs:line 40
This seems to have been because I was exiting the move loop when a checkmate was found. This short-circuited the undo and so further down in the search the board state was not the expected value when closing down the search loop. So not a problem with UndoMove, but in how it was used.