/// <summary>
/// The user has released a dragged piece. Verify that its a legal move, if so perform the move and perform the next move if appropriate mode.
/// </summary>
/// <param name="piece"></param>
private void _pieceUp(cgChessPieceScript piece)
{
if (_downPiece != null)
{
if (playerCanMove || Mode == BoardMode.PlayerVsPlayer)
{
cgSimpleMove legalMove = null;
cgSquareScript closestSquare = _findSquareAt(_downPiece.transform.position);
List <cgSimpleMove> legalMoves = _abstractBoard.findLegalMoves(whiteTurnToMove);
foreach (cgSimpleMove move in legalMoves)
{
if (cgGlobal.SquareNames[move.from] == _downPiece.square.uniqueName && cgGlobal.SquareNames[move.to] == closestSquare.uniqueName)
{
legalMove = move;
}
}
//test legality of move here.
if (legalMove != null && _abstractBoard.verifyLegality(legalMove))
{
//piece.moveToSquare(closestSquare);
_makeMove(legalMove);
if (Mode == BoardMode.PlayerVsEngine)
{
_engine.MakeMove(_abstractBoard, false, _engineCallback);
}
else if (Mode == BoardMode.EngineVsPlayer)
{
_engine.MakeMove(_abstractBoard, true, _engineCallback);
}
}
else
{
piece.moveToSquare(piece.square);
}
}
else
{
piece.moveToSquare(piece.square);
}
_downPiece = null;
}
else
{
piece.moveToSquare(piece.square);
_downPiece = null;
}
if (highlightLastMove)
{//revert colors if highlighting is active
foreach (cgSquareScript square in _squares)
{
square.changeColor(square.startColor);
}
}
}
/// <summary>
/// Utilizing an AlphaBeta searching algorithm, we generate moves evaluate them, prune and decide which is best.
/// https://en.wikipedia.org/wiki/Alpha%E2%80%93beta_pruning
/// </summary>
/// <param name="node">the move to analyze</param>
/// <param name="depth">The max depth to search to, execution time increases exponentially the higher the depth</param>
/// <param name="alpha"></param>
/// <param name="beta"></param>
/// <param name="maximizing"></param>
/// <returns>The value of the provided node</returns>
private int _alfaBeta(cgSimpleMove node, int depth, int alpha = int.MinValue, int beta = int.MaxValue, bool maximizing = true)
{
_board.move(node);
if (depth == 0)
{
int val = _board.Evaluate();
_board.revert();
return(val);
}
if (maximizing)
{
int v = int.MinValue;
List <cgSimpleMove> replies = _board.findLegalMoves(true);
foreach (cgSimpleMove reply in replies)
{
int candidate = _alfaBeta(reply, depth - 1, alpha, beta, false);
v = candidate > v ? candidate : v;
alpha = alpha > v ? alpha : v;
if (beta < alpha)
{
break;
}
}
_board.revert();
return(v);
}
else
{
int v = int.MaxValue;
List <cgSimpleMove> replies = _board.findLegalMoves(false);
foreach (cgSimpleMove reply in replies)
{
int candidate = _alfaBeta(reply, depth - 1, alpha, beta, true);
v = candidate < v ? candidate : v;
if (beta > v)
{
beta = v;
//node.bestResponse = reply;
}
if (beta < alpha)
{
break;
}
}
_board.revert();
return(v);
}
}
/// <summary>
/// Writes the full game notation from the current moves stored in Moves list.
/// </summary>
/// <param name="type">What notationtype should it be?</param>
/// <param name="formatType">Should it be PGN format or not?</param>
/// <returns>A string with full game notation.</returns>
public string writeFullNotation(NotationType type, FormatType formatType = FormatType.None)
{
string str = "";
cgBoard disambiguationBoard = board.duplicate().revertToStart();
if (type == NotationType.Coordinate)
{
foreach (cgSimpleMove pcem in moves)
{
str += (disambiguationBoard.SquareNames[pcem.from] + "-" + disambiguationBoard.SquareNames[pcem.to]) + " ";
}
}
if (formatType == FormatType.PGN)
{
string q = "\"";
str = " [Event " + q + "Pro Chess" + q + "]\n";
str += " [Site " + q + "Undefined site" + q + "]\n";
str += " [Date " + q + DateTime.Now + q + "]\n";
str += " [White " + q + "Chessplayer1" + q + "]\n";
str += " [Black " + q + "Chessplayer2" + q + "]\n";
str += " [Result " + q + "1/2-1/2" + q + "]\n";
}
if (type == NotationType.Algebraic)
{
foreach (cgSimpleMove pcem in moves)
{
if (disambiguationBoard.moves.Count % 2 == 0)
{
str += (Math.Floor(disambiguationBoard.moves.Count / 2f) + 1).ToString() + ". ";
}
int typ = Math.Abs(disambiguationBoard.squares[pcem.from]);
List <cgSimpleMove> othermoves = disambiguationBoard.findLegalMoves(disambiguationBoard.whiteTurnToMove);
List <cgSimpleMove> ambiguousMoves = new List <cgSimpleMove>();
foreach (cgSimpleMove othermove in othermoves)
{
if (othermove.to == pcem.to && othermove.from != pcem.from && Math.Abs(disambiguationBoard.squares[othermove.from]) == typ)
{
ambiguousMoves.Add(othermove);
}
}
if (typ == 1 && pcem.capturedType != 0)
{
str += disambiguationBoard.SquareNames[pcem.from].Substring(0, 1);
}
if (typ == 2)
{
str += "R";
}
if (typ == 3)
{
str += "N";
}
if (typ == 4)
{
str += "B";
}
if (typ == 5)
{
str += "Q";
}
if (typ == 6 && !(pcem is cgCastlingMove))
{
str += "K";
}
//if (typ == 6) str += "K";
if (ambiguousMoves.Count > 0 && typ != 1)
{
bool fileMatch = false;
bool rankMatch = false;
foreach (cgSimpleMove ambiguousMove in ambiguousMoves)
{
if (disambiguationBoard.SquareNames[ambiguousMove.from].Substring(0, 1) == disambiguationBoard.SquareNames[pcem.from].Substring(0, 1))
{
fileMatch = true;
}
if (disambiguationBoard.SquareNames[ambiguousMove.from].Substring(1, 1) == disambiguationBoard.SquareNames[pcem.from].Substring(1, 1))
{
rankMatch = true;
}
}
if (!fileMatch)
{
str += disambiguationBoard.SquareNames[pcem.from].Substring(0, 1);
}
else if (fileMatch && !rankMatch)
{
str += disambiguationBoard.SquareNames[pcem.from].Substring(1, 1);
}
else if (fileMatch && rankMatch)
{
str += disambiguationBoard.SquareNames[pcem.from];
}
}
if (pcem.capturedType != 0)
{
str += "x";
}
if (pcem is cgCastlingMove)
{
if (pcem.to == 2 || pcem.to == 58)
{
str += "O-O-O";
}
else
{
str += "O-O";
}
}
else
{
str += disambiguationBoard.SquareNames[pcem.to];
}
if (pcem.queened)
{
str += "=Q";
}
str += " ";
disambiguationBoard.move(pcem);
}
}
return(str);
}
/// <summary>
/// Read the notations in the provided string.
/// </summary>
/// <param name="curgame">the string to decipher.</param>
public void Read(string curgame)
{
int lastIndex = 0;
int nextIndex = 0;
string move = curgame.Substring(lastIndex, nextIndex);
NotationType ntype = NotationType.Algebraic; //= NotationType.Coordinate;
//Debug.Log("first move:" + move);
//if (move.Contains("-")) ntype = NotationType.Coordinate;
moves = new List <cgSimpleMove>();
if (ntype == NotationType.Coordinate)
{
while (lastIndex != -1)
{
byte fromp = board.IndexFromCellName(move.Substring(0, 2));
byte top = board.IndexFromCellName(move.Substring(3, 2));
moves.Add(new cgSimpleMove(fromp, top));
nextIndex = curgame.IndexOf(" ", lastIndex + 1);
if (nextIndex == -1)
{
break;
}
move = curgame.Substring(lastIndex + 1, nextIndex - lastIndex);
lastIndex = nextIndex;
//Debug.Log("current move being analyzed="+move);
}
}
else if (ntype == NotationType.Algebraic)
{
cgBoard disambBoard = new cgBoard();
cgSimpleMove chosenMove;
while (lastIndex != -1)
{
chosenMove = null;
nextIndex = curgame.IndexOf(" ", nextIndex + 1);
if (nextIndex == -1 || lastIndex == -1)
{
break;
}
move = curgame.Substring(lastIndex + 1, nextIndex - lastIndex);
bool legitMove = (!move.Contains(".") && move.Length > 1 && !move.Contains("\n")) ? true : false;
move = move.Trim(' ');
//move = move.Trim('\n');
//Debug.Log("trimmed:" + move+" contains .:"+move.Contains(".")+" contains newline:"+move.Contains("\n")+" legit move:"+legitMove);
if (move.Contains("{"))
{
nextIndex = curgame.IndexOf("}", lastIndex + 1);
}
else if (move.Contains("["))
{
nextIndex = curgame.IndexOf("]", lastIndex + 1);
}
else if (legitMove)
{
//Debug.Log("found to be legit move.");
byte tosquare;
byte pushback = 2;
byte type = 1;
//bool promotion = false;
bool shortCastling = (move == "O-O");
bool longCastling = (move == "O-O-O");
if (move.Contains("="))
{
//promotion = true;
move.Remove(move.IndexOf("="), 2);
}
else if (move.Contains("+"))
{
move.Remove(move.IndexOf("+"), 1);
}
else if (move.Contains("!"))
{
move.Remove(move.IndexOf("!"), 1);
}
else if (move.Contains("?"))
{
move.Remove(move.IndexOf("?"), 1);
}
tosquare = board.IndexFromCellName(move.Substring(move.Length - pushback, 2));
if (move[0] == 'R')
{
type = 2;
}
if (move[0] == 'N')
{
type = 3;
}
if (move[0] == 'B')
{
type = 4;
}
if (move[0] == 'Q')
{
type = 5;
}
if (move[0] == 'K')
{
type = 6;
}
List <cgSimpleMove> ambiguousMoves = new List <cgSimpleMove>();
foreach (cgSimpleMove legalMove in disambBoard.findLegalMoves(disambBoard.whiteTurnToMove))
{
if (shortCastling && legalMove is cgCastlingMove)
{
if (legalMove.to == 6 || legalMove.to == 62)
{
chosenMove = legalMove;
break;
}
}
else if (longCastling && legalMove is cgCastlingMove)
{
if (legalMove.to == 2 || legalMove.to == 58)
{
chosenMove = legalMove;
break;
}
}
if (Math.Abs(disambBoard.squares[legalMove.from]) == type && legalMove.to == tosquare)
{
ambiguousMoves.Add(legalMove);
}
}
if (ambiguousMoves.Count == 0 && chosenMove == null)
{
//Debug.WriteLine("found no matching move for the string: " + move+" type:"+type+" tosquare:"+tosquare+" chosenMove:"+chosenMove+" castling:"+shortCastling);
break;
}
else if (ambiguousMoves.Count == 1)
{
chosenMove = ambiguousMoves[0];
}
else if (ambiguousMoves.Count > 1)
{
//UnityEngine.Debug.Log("2 or mroe ambiguousmoves");
//2 or more ambiguous moves in which the piece type matches and the destination square matches. Further disambiguation needed.
List <cgSimpleMove> matching = new List <cgSimpleMove>();
foreach (cgSimpleMove mov in ambiguousMoves)
{
if (board.SquareNames[mov.from].Contains(move.Substring(1 + (type == 1?-1:0), 1)))
{
matching.Add(mov);
}
}
if (matching.Count == 1)
{
chosenMove = matching[0]; //only 1 of the ambiguous moves have the correct rank and/or file.
}
else
{
foreach (cgSimpleMove mov in ambiguousMoves)
{
if (board.SquareNames[mov.from].Contains(move.Substring(1, 2)))
{
chosenMove = ambiguousMoves[0];
break;
}
}
}
}
if (chosenMove != null)
{
disambBoard.move(chosenMove);
moves.Add(chosenMove);
}
}
Debug.WriteLine("legitmove:" + legitMove);
lastIndex = nextIndex;
}
}
}
public static string NotationFromMove(cgBoard _board, cgSimpleMove _move)
{
string str = "";
if (_board.moves.Count % 2 == 0)
{
str += (Math.Floor(_board.moves.Count / 2f) + 1).ToString() + ". ";
}
int typ = Mathf.Abs(_board.squares[_move.from]);
List <cgSimpleMove> othermoves = _board.findLegalMoves(_board.whiteTurnToMove);
List <cgSimpleMove> ambiguousMoves = new List <cgSimpleMove>();
foreach (cgSimpleMove othermove in othermoves)
{
if (othermove.to == _move.to && othermove.from != _move.from && Mathf.Abs(_board.squares[othermove.from]) == typ)
{
ambiguousMoves.Add(othermove);
}
}
if (typ == 1 && _move.capturedType != 0)
{
str += cgGlobal.SquareNames[_move.from].Substring(0, 1);
}
if (typ == 2)
{
str += "R";
}
if (typ == 3)
{
str += "N";
}
if (typ == 4)
{
str += "B";
}
if (typ == 5)
{
str += "Q";
}
if (typ == 6 && !(_move is cgCastlingMove))
{
str += "K";
}
//if (typ == 6) str += "K";
if (ambiguousMoves.Count > 0 && typ != 1)
{
bool fileMatch = false;
bool rankMatch = false;
foreach (cgSimpleMove ambiguousMove in ambiguousMoves)
{
if (cgGlobal.SquareNames[ambiguousMove.from].Substring(0, 1) == cgGlobal.SquareNames[_move.from].Substring(0, 1))
{
fileMatch = true;
}
if (cgGlobal.SquareNames[ambiguousMove.from].Substring(1, 1) == cgGlobal.SquareNames[_move.from].Substring(1, 1))
{
rankMatch = true;
}
}
if (!fileMatch)
{
str += cgGlobal.SquareNames[_move.from].Substring(0, 1);
}
else if (fileMatch && !rankMatch)
{
str += cgGlobal.SquareNames[_move.from].Substring(1, 1);
}
else if (fileMatch && rankMatch)
{
str += cgGlobal.SquareNames[_move.from];
}
}
if (_move.capturedType != 0)
{
str += "x";
}
if (_move is cgCastlingMove)
{
if (_move.to == 2 || _move.to == 58)
{
str += "O-O-O";
}
else
{
str += "O-O";
}
}
else
{
str += cgGlobal.SquareNames[_move.to];
}
if (_move.promoted)
{
switch (_move.promotionType)
{
case 2:
str += "=R";
break;
case 3:
str += "=N";
break;
case 4:
str += "=B";
break;
case 5:
str += "=Q";
break;
default:
break;
}
}
return(str);
}
