private static void Perft(BoardState boardState, int depth, AdvancedPerftResult result)
{
Span <Move> moves = stackalloc Move[SearchConstants.MaxMovesCount];
var movesCount = boardState.GetAllMoves(moves);
if (depth <= 0)
{
result.Leafs++;
return;
}
if (depth == 1)
{
UpdateResult(boardState, moves, movesCount, result);
return;
}
for (var i = 0; i < movesCount; i++)
{
boardState.MakeMove(moves[i]);
if (!boardState.IsKingChecked(ColorOperations.Invert(boardState.ColorToMove)))
{
Perft(boardState, depth - 1, result);
}
boardState.UndoMove(moves[i]);
}
}
public static AdvancedPerftResult Run(BoardState boardState, int depth)
{
var result = new AdvancedPerftResult();
var stopwatch = Stopwatch.StartNew();
Perft(boardState, depth, result);
result.Time = stopwatch.Elapsed.TotalSeconds;
return(result);
}
private static void UpdateResult(BoardState boardState, Span <Move> moves, int movesCount, AdvancedPerftResult result)
{
var legalMoveFound = false;
for (var i = 0; i < movesCount; i++)
{
boardState.MakeMove(moves[i]);
if (!boardState.IsKingChecked(ColorOperations.Invert(boardState.ColorToMove)))
{
if (moves[i].IsCapture())
{
result.Captures++;
}
if (moves[i].Flags == MoveFlags.KingCastle || moves[i].Flags == MoveFlags.QueenCastle)
{
result.Castles++;
}
if (moves[i].Flags == MoveFlags.EnPassant)
{
result.EnPassants++;
result.Captures++;
}
if (boardState.IsKingChecked(boardState.ColorToMove))
{
result.Checks++;
}
result.Leafs++;
legalMoveFound = true;
}
boardState.UndoMove(moves[i]);
}
if (!legalMoveFound)
{
result.Checkmates++;
}
}
