private Square pgnLength5(GameState gameState, string newPgnMove)
{
var _file = NotationEngine.FileToInt(newPgnMove[1]);
var _rank = 0;
Int32.TryParse(newPgnMove[2].ToString(), out _rank);
var pos = NotationEngine.CoordinatePairToPosition(_file, _rank);
return(gameState.Squares.GetSquare(pos));
}
private void getPawnDiagonalAttack(List <Square> squares, Square square, Color pieceColor, int fileIndicator, int nextRank, List <AttackedSquare> attacks)
{
var pos = NotationEngine.CoordinatePairToPosition(fileIndicator, nextRank);
var attackedSquare = squares.GetSquare(pos);
if (attackedSquare.Occupied && attackedSquare.Piece.Color != pieceColor)
{
attacks.Add(new AttackedSquare(square, attackedSquare, false, true));
}
else
{
attacks.Add(new AttackedSquare(square, attackedSquare, false, true, true));
}
}
private void getPawnAttacks(GameState gameState, Square square, List <AttackedSquare> accumulator)
{
var squares = gameState.Squares;
var position = square.Index;
var pieceColor = square.Piece.Color;
var coord = NotationEngine.PositionToCoordinate(position);
int file = NotationEngine.FileToInt(coord[0]);
int rank = NotationEngine.PositionToRankInt(position);
var directionIndicator = pieceColor == Color.White ? 1 : -1;
var homeRankIndicator = pieceColor == Color.White ? 2 : 7;
var nextRank = (rank + directionIndicator);
var aheadOneRankPosition = NotationEngine.CoordinatePairToPosition(file, nextRank);
var aheadOneRankSquare = squares.GetSquare(aheadOneRankPosition);
var attacks = new List <AttackedSquare>();
if (!aheadOneRankSquare.Occupied)
{
//can't attack going forward
attacks.Add(new AttackedSquare(square, aheadOneRankSquare, true));
}
managePawnAttacks(squares, square, pieceColor, file, rank, directionIndicator, homeRankIndicator, nextRank, attacks, aheadOneRankSquare.Occupied);
//add en passant position: -1 indicates null here
if (gameState.EnPassantTargetSquare != "-")
{
var enPassantTargetPosition = NotationEngine.CoordinateToPosition(gameState.EnPassantTargetSquare);
var leftPos = NotationEngine.CoordinatePairToPosition(file - 1, nextRank);
var rightPos = NotationEngine.CoordinatePairToPosition(file + 1, nextRank);
if (enPassantTargetPosition == leftPos || enPassantTargetPosition == rightPos)
{
var enPassantSquare = squares.GetSquare(enPassantTargetPosition);
attacks.Add(new AttackedSquare(square, enPassantSquare));
}
}
if (attacks.Any())
{
accumulator.AddRange(attacks);
}
}
private void managePawnAttacks(List <Square> squares, Square square, Color pieceColor, int file, int rank, int directionIndicator, int homeRankIndicator, int nextRank, List <AttackedSquare> attacks, bool aheadOneRankSquareOccupied)
{
var notOnFarLeftFile = file - 1 >= 0;
var notOnFarRightFile = file + 1 <= 7;
if (notOnFarLeftFile)
{
//get attack square on left
var fileIndicator = file - 1;
getPawnDiagonalAttack(squares, square, pieceColor, fileIndicator, nextRank, attacks);
}
if (notOnFarRightFile)
{
//get attack square on right
var fileIndicator = file + 1;
getPawnDiagonalAttack(squares, square, pieceColor, fileIndicator, nextRank, attacks);
}
//can't move ahead two if the one in front of you is blocked.
if (aheadOneRankSquareOccupied)
{
return;
}
//have to plus one here because rank is zero based and coordinate is base 1
//if this pawn is on it's home rank, then add a second attack square.
var isOnHomeRank = rank + 1 == homeRankIndicator;
if (isOnHomeRank)
{
var forwardOne = nextRank + directionIndicator;
var rankForwardPosition = NotationEngine.CoordinatePairToPosition(file, forwardOne);
var rankForwardSquare = squares.GetSquare(rankForwardPosition);
//pawns don't attack forward, so we don't have attacks when people occupy ahead of us
if (!rankForwardSquare.Occupied)
{
attacks.Add(new AttackedSquare(square, rankForwardSquare, true));
}
}
}