public double GetScore(IChessBoard board, ChessColor sideToDraw)
{
// get allied pieces and calculate the score
double allyScore = board.GetPiecesOfColor(sideToDraw).Select(x => getPieceScore(board, x.Position)).Sum();
double enemyScore = board.GetPiecesOfColor(sideToDraw.Opponent()).Select(x => getPieceScore(board, x.Position)).Sum();
// calculate the relative score: the own score compared to the opponent's score
return(allyScore - enemyScore);
}
private IEnumerable <ChessDraw> getRochadeDraws(IChessBoard board, ChessColor drawingSide)
{
// TODO: do optimizations!!!
// get enemy capturable positions
var enemyKing = (drawingSide == ChessColor.White) ? board.BlackKing : board.WhiteKing;
var enemyCapturablePositions =
board.GetPiecesOfColor(drawingSide.Opponent()).Where(x => x.Piece.Type != ChessPieceType.King)
.SelectMany(x => ChessDrawGenerator.Instance.GetDraws(board, x.Position, null, false)).Select(x => x.NewPosition)
.Concat(getStandardDrawPositions(enemyKing.Position));
// get the allied king and towers
int row = (drawingSide == ChessColor.White) ? 0 : 7;
var alliedKing = (drawingSide == ChessColor.White) ? board.WhiteKing : board.BlackKing;
var farAlliedTowerPos = new ChessPosition(row, 0);
var farAlliedTower = board.GetPieceAt(farAlliedTowerPos);
var nearAlliedTowerPos = new ChessPosition(row, 7);
var nearAlliedTower = board.GetPieceAt(nearAlliedTowerPos);
// define the fields that must not be capturable by the opponent
var bigRochadeKingPassagePositions = (drawingSide == ChessColor.White) ? whiteKingBigRochadePassagePositions : blackKingBigRochadePassagePositions;
var smallRochadeKingPassagePositions = (drawingSide == ChessColor.White) ? whiteKingSmallRochadePassagePositions : blackKingSmallRochadePassagePositions;
bool canBigRochade =
// check for preconditions of big rochade
(board.IsCapturedAt(farAlliedTowerPos) && !alliedKing.Piece.WasMoved && !farAlliedTower.WasMoved &&
bigRochadeKingPassagePositions.All(x => !board.IsCapturedAt(x) || (board.GetPieceAt(x).Color == drawingSide && board.GetPieceAt(x).Type == ChessPieceType.King)) &&
!board.IsCapturedAt(new ChessPosition(row, 1)))
// make sure that no rochade field can be captured by the opponent
&& !enemyCapturablePositions.Any(pos => bigRochadeKingPassagePositions.Contains(pos));
bool canSmallRochade =
// check for preconditions of small rochade
(board.IsCapturedAt(nearAlliedTowerPos) && !alliedKing.Piece.WasMoved && !nearAlliedTower.WasMoved &&
smallRochadeKingPassagePositions.All(x => !board.IsCapturedAt(x) || (board.GetPieceAt(x).Color == drawingSide && board.GetPieceAt(x).Type == ChessPieceType.King)))
// make sure that no rochade field can be captured by the opponent and the rochade field on the B-line is not captured
&& !enemyCapturablePositions.Any(pos => smallRochadeKingPassagePositions.Contains(pos));
// write result draws
int index = 0;
int drawsCount = (canSmallRochade ? 1 : 0) + (canBigRochade ? 1 : 0);
ChessDraw[] draws = new ChessDraw[drawsCount];
if (canSmallRochade)
{
draws[index++] = new ChessDraw(board, alliedKing.Position, new ChessPosition(row, 6));
}
if (canBigRochade)
{
draws[index++] = new ChessDraw(board, alliedKing.Position, new ChessPosition(row, 2));
}
return(draws);
}
