internal static MoveContent IterativeSearch(Board examineBoard, byte depth, ref int nodesSearched, ref int nodesQuiessence, ref string pvLine, ref byte plyDepthReached, ref byte rootMovesSearched, List <OpeningMove> currentGameBook)
{
List <Position> pvChild = new List <Position>();
int alpha = -400000000;
const int beta = 400000000;
MoveContent bestMove = new MoveContent();
//We are going to store our result boards here
ResultBoards succ = GetSortValidMoves(examineBoard);
rootMovesSearched = (byte)succ.Positions.Count;
if (rootMovesSearched == 1)
{
//I only have one move
return(succ.Positions[0].LastMove);
}
//Can I make an instant mate?
foreach (Board pos in succ.Positions)
{
int value = -AlphaBeta(pos, 1, -beta, -alpha, ref nodesSearched, ref nodesQuiessence, ref pvChild, true);
if (value >= 32767)
{
return(pos.LastMove);
}
}
int currentBoard = 0;
alpha = -400000000;
succ.Positions.Sort(Sort);
depth--;
plyDepthReached = ModifyDepth(depth, succ.Positions.Count);
foreach (Board pos in succ.Positions)
{
currentBoard++;
progress = (int)((currentBoard / (decimal)succ.Positions.Count) * 100);
pvChild = new List <Position>();
int value = -AlphaBeta(pos, depth, -beta, -alpha, ref nodesSearched, ref nodesQuiessence, ref pvChild, false);
if (value >= 32767)
{
return(pos.LastMove);
}
if (examineBoard.RepeatedMove == 2)
{
string fen = Board.Fen(true, pos);
foreach (OpeningMove move in currentGameBook)
{
if (move.EndingFEN == fen)
{
value = 0;
break;
}
}
}
pos.Score = value;
//If value is greater then alpha this is the best board
if (value > alpha || alpha == -400000000)
{
pvLine = pos.LastMove.ToString();
foreach (Position pvPos in pvChild)
{
pvLine += " " + pvPos.ToString();
}
alpha = value;
bestMove = pos.LastMove;
}
}
plyDepthReached++;
progress = 100;
return(bestMove);
}
private static ResultBoards GetSortValidMoves(Board examineBoard)
{
ResultBoards succ = new ResultBoards
{
Positions = new List <Board>(30)
};
piecesRemaining = 0;
for (byte x = 0; x < 64; x++)
{
Square sqr = examineBoard.Squares[x];
//Make sure there is a piece on the square
if (sqr.Piece == null)
{
continue;
}
piecesRemaining++;
//Make sure the color is the same color as the one we are moving.
if (sqr.Piece.PieceColor != examineBoard.WhoseMove)
{
continue;
}
//For each valid move for this piece
foreach (byte dst in sqr.Piece.ValidMoves)
{
//We make copies of the board and move so that we can move it without effecting the parent board
Board board = examineBoard.FastCopy();
//Make move so we can examine it
Board.MovePiece(board, x, dst, ChessPieceType.Queen);
//We Generate Valid Moves for Board
PieceValidMoves.GenerateValidMoves(board);
//Invalid Move
if (board.WhiteCheck && examineBoard.WhoseMove == ChessPieceColor.White)
{
continue;
}
//Invalid Move
if (board.BlackCheck && examineBoard.WhoseMove == ChessPieceColor.Black)
{
continue;
}
//We calculate the board score
Evaluation.EvaluateBoardScore(board);
//Invert Score to support Negamax
board.Score = SideToMoveScore(board.Score, board.WhoseMove);
succ.Positions.Add(board);
}
}
succ.Positions.Sort(Sort);
return(succ);
}
public void AiPonderMove()
{
Thinking = true;
NodesSearched = 0;
var resultBoards = new ResultBoards();
resultBoards.Positions = new List <Board>();
if (CheckForMate(WhoseMove, ref ChessBoard))
{
Thinking = false;
return;
}
MoveContent bestMove = new MoveContent();
//If there is no playbook move search for the best move
if (FindPlayBookMove(ref bestMove, ChessBoard, OpeningBook) == false ||
ChessBoard.FiftyMove > 45 || ChessBoard.RepeatedMove >= 2)
{
if (FindPlayBookMove(ref bestMove, ChessBoard, CurrentGameBook) == false ||
ChessBoard.FiftyMove > 45 || ChessBoard.RepeatedMove >= 2)
{
bestMove = Search.IterativeSearch(ChessBoard, PlyDepthSearched, CurrentGameBook);
}
}
//Make the move
PreviousChessBoard = new Board(ChessBoard);
RootMovesSearched = (byte)resultBoards.Positions.Count;
Board.MovePiece(ChessBoard, bestMove.MovingPiecePrimary.SrcPosition, bestMove.MovingPiecePrimary.DstPosition, ChessPieceType.Queen);
ChessBoard.LastMove.GeneratePGNString(ChessBoard);
FileIO.SaveCurrentGameMove(ChessBoard, PreviousChessBoard, CurrentGameBook, bestMove);
for (byte x = 0; x < 64; x++)
{
Square sqr = ChessBoard.Squares[x];
if (sqr.Piece == null)
{
continue;
}
sqr.Piece.DefendedValue = 0;
sqr.Piece.AttackedValue = 0;
}
PieceValidMoves.GenerateValidMoves(ChessBoard);
Evaluation.EvaluateBoardScore(ChessBoard);
PieceTakenAdd(ChessBoard.LastMove);
MoveHistory.Push(ChessBoard.LastMove);
if (CheckForMate(WhoseMove, ref ChessBoard))
{
Thinking = false;
if (ChessBoard.WhiteMate || ChessBoard.BlackMate)
{
LastMove.PgnMove += "#";
}
return;
}
if (ChessBoard.WhiteCheck || ChessBoard.BlackCheck)
{
LastMove.PgnMove += "+";
}
Thinking = false;
}
public void AiPonderMove()
{
Thinking = true;
/* Fix added to prevent premature declaration of checkmate against computer's king.
*
* The original version only looked at squares that were available for the black king to move to PRIOR to white's latest move.
* So... suppose you had a situation like this:
* r4r2/pppb1p1k/8/3p2Q1/q4P2/2np4/6PP/5RK1/ w - 0 27
* ... and moved the white queen from G5 to H5.
* At the start of white's move, the black king has 5 possible moves... 4 of which are attackable by white, and noted by
* GenerateValidMoves in WhiteAttackBoard[]. When AiPonderMove executes, it immediately eliminates those 4 squares as options
* for the black king, even though 2 of them are now safe because no white piece can attack them. However, square 7 is now
* directly in the queen's attack path, so it's eliminated as an option as well. Boom, premature checkmate... game over.
*/
ChessBoard.BlackMate = false;
ChessBoard.WhiteMate = false;
PieceValidMoves.GenerateValidMoves(ChessBoard);
NodesSearched = 0;
var resultBoards = new ResultBoards();
resultBoards.Positions = new List <Board>();
if (CheckForMate(WhoseMove, ref ChessBoard))
{
Thinking = false;
return;
}
MoveContent bestMove = new MoveContent();
//If there is no playbook move search for the best move
if (FindPlayBookMove(ref bestMove, ChessBoard, OpeningBook) == false ||
ChessBoard.HalfMoveClock > 90 || ChessBoard.RepeatedMove >= 2)
{
if (FindPlayBookMove(ref bestMove, ChessBoard, CurrentGameBook) == false ||
ChessBoard.HalfMoveClock > 90 || ChessBoard.RepeatedMove >= 2)
{
bestMove = Search.IterativeSearch(ChessBoard, PlyDepthSearched, ref NodesSearched, ref NodesQuiessence, ref pvLine, ref PlyDepthReached, ref RootMovesSearched, CurrentGameBook);
}
}
//Make the move
PreviousChessBoard = new Board(ChessBoard);
RootMovesSearched = (byte)resultBoards.Positions.Count;
Board.MovePiece(ChessBoard, bestMove.MovingPiecePrimary.SrcPosition, bestMove.MovingPiecePrimary.DstPosition, ChessPieceType.Queen);
ChessBoard.LastMove.GeneratePGNString(ChessBoard);
FileIO.SaveCurrentGameMove(ChessBoard, PreviousChessBoard, CurrentGameBook, bestMove);
for (byte x = 0; x < 64; x++)
{
Square sqr = ChessBoard.Squares[x];
if (sqr.Piece == null)
{
continue;
}
sqr.Piece.DefendedValue = 0;
sqr.Piece.AttackedValue = 0;
}
PieceValidMoves.GenerateValidMoves(ChessBoard);
Evaluation.EvaluateBoardScore(ChessBoard);
PieceTakenAdd(ChessBoard.LastMove);
MoveHistory.Push(ChessBoard.LastMove);
if (CheckForMate(WhoseMove, ref ChessBoard))
{
Thinking = false;
if (ChessBoard.WhiteMate || ChessBoard.BlackMate)
{
LastMove.PgnMove += "#";
}
return;
}
if (ChessBoard.WhiteCheck || ChessBoard.BlackCheck)
{
LastMove.PgnMove += "+";
}
Thinking = false;
}
internal static MoveContent IterativeSearchOld(Board examineBoard, ChessEngine.Engine.Engine.TimeSettings gameTimeSettings, ref int nodesSearched, ref int nodesQuiessence, ref string pvLine, BackgroundWorker worker, ref byte plyDepthReached, ref byte rootMovesSearched, List <OpeningMove> currentGameBook)
{
Zobrist.MarkAncient();
MoveContent moveContent1 = new MoveContent();
MoveContent moveContent2 = new MoveContent();
string str1 = "";
List <Search.Position> positionList1 = new List <Search.Position>();
ResultBoards sortValidMoves = Search.GetSortValidMoves(examineBoard);
rootMovesSearched = (byte)sortValidMoves.Positions.Count;
int num1 = 30;
int num2 = 40;
byte depth = 1;
if (gameTimeSettings == ChessEngine.Engine.Engine.TimeSettings.Moves40In10Minutes)
{
num1 = 15;
}
else if (gameTimeSettings == ChessEngine.Engine.Engine.TimeSettings.Moves40In20Minutes)
{
num1 = 30;
}
else if (gameTimeSettings == ChessEngine.Engine.Engine.TimeSettings.Moves40In30Minutes)
{
num1 = 45;
}
else if (gameTimeSettings == ChessEngine.Engine.Engine.TimeSettings.Moves40In40Minutes)
{
num1 = 60;
}
else if (gameTimeSettings == ChessEngine.Engine.Engine.TimeSettings.Moves40In60Minutes)
{
num1 = 90;
}
else if (gameTimeSettings == ChessEngine.Engine.Engine.TimeSettings.Moves40In90Minutes)
{
num1 = 135;
}
DateTime now = DateTime.Now;
do
{
pvLine = "";
int num3 = -400000000;
sortValidMoves.Positions.Sort(new Comparison <Board>(Search.Sort));
foreach (Board position1 in sortValidMoves.Positions)
{
if (DateTime.Now - now > TimeSpan.FromSeconds((double)num1))
{
pvLine = str1;
return(moveContent2);
}
if (worker != null)
{
worker.ReportProgress((int)((DateTime.Now - now).TotalSeconds / (double)num1 * 100.0));
}
List <Search.Position> pvLine1 = new List <Search.Position>();
int num4 = -Search.AlphaBeta(position1, depth, -400000000, -num3, ref nodesSearched, ref nodesQuiessence, ref pvLine1, true);
if (num4 >= (int)short.MaxValue)
{
pvLine = str1;
return(position1.LastMove);
}
if ((int)examineBoard.RepeatedMove == 2)
{
string str2 = Board.Fen(true, position1);
foreach (OpeningMove openingMove in currentGameBook)
{
if (openingMove.EndingFEN == str2)
{
num4 = 0;
break;
}
}
}
position1.Score = num4;
if (num4 > num3)
{
List <Search.Position> positionList2 = new List <Search.Position>();
pvLine = position1.LastMove.ToString();
foreach (Search.Position position2 in pvLine1)
{
pvLine = pvLine + " " + position2.ToString();
positionList2.Add(position2);
}
positionList2.Reverse();
num3 = num4;
moveContent1 = position1.LastMove;
}
}
moveContent2 = moveContent1;
str1 = pvLine;
plyDepthReached = depth;
++depth;
}while (DateTime.Now - now < TimeSpan.FromSeconds((double)num1) && (int)plyDepthReached < 19);
plyDepthReached = (byte)((uint)plyDepthReached + 1U);
int num5 = num2 != 1 ? num2 - 1 : 40;
return(moveContent2);
}
internal static MoveContent IterativeSearch(Board examineBoard, byte depth, ref int nodesSearched, ref int nodesQuiessence, ref string pvLine, BackgroundWorker worker, ref byte plyDepthReached, ref byte rootMovesSearched, List <OpeningMove> currentGameBook)
{
List <Search.Position> pvLine1 = new List <Search.Position>();
int num1 = -400000000;
Zobrist.MarkAncient();
MoveContent moveContent = new MoveContent();
ResultBoards sortValidMoves = Search.GetSortValidMoves(examineBoard);
rootMovesSearched = (byte)sortValidMoves.Positions.Count;
if ((int)rootMovesSearched == 1)
{
return(sortValidMoves.Positions[0].LastMove);
}
foreach (Board position in sortValidMoves.Positions)
{
if (-Search.AlphaBeta(position, (byte)1, -400000000, -num1, ref nodesSearched, ref nodesQuiessence, ref pvLine1, true) >= (int)short.MaxValue)
{
return(position.LastMove);
}
}
int num2 = 0;
int num3 = -400000000;
sortValidMoves.Positions.Sort(new Comparison <Board>(Search.Sort));
--depth;
plyDepthReached = Search.ModifyDepth(depth, sortValidMoves.Positions.Count);
foreach (Board position1 in sortValidMoves.Positions)
{
++num2;
if (worker != null)
{
worker.ReportProgress((int)((Decimal)num2 / (Decimal)sortValidMoves.Positions.Count * new Decimal(100)));
}
List <Search.Position> pvLine2 = new List <Search.Position>();
int num4 = -Search.AlphaBeta(position1, depth, -400000000, -num3, ref nodesSearched, ref nodesQuiessence, ref pvLine2, false);
if (num4 >= (int)short.MaxValue)
{
return(position1.LastMove);
}
if ((int)examineBoard.RepeatedMove == 2)
{
string str = Board.Fen(true, position1);
foreach (OpeningMove openingMove in currentGameBook)
{
if (openingMove.EndingFEN == str)
{
num4 = 0;
break;
}
}
}
position1.Score = num4;
if (num4 > num3 || num3 == -400000000)
{
pvLine = position1.LastMove.ToString();
foreach (Search.Position position2 in pvLine2)
{
pvLine = pvLine + " " + position2.ToString();
}
num3 = num4;
moveContent = position1.LastMove;
}
}
plyDepthReached = (byte)((uint)plyDepthReached + 1U);
return(moveContent);
}