private IEnumerable <int> GetCastlingPositions(Gameboard gameboard)
{
bool EmptyAndNoCheck(int direction, BasePiece rookTile)
{
if (!(rookTile is Rook) || rookTile.HasMoved)
{
return(false);
}
if (direction < 0)
{
for (int index = Position + direction; index >= rookTile.Position; index--)
{
if (gameboard.Board[index] != null)
{
return(false);
}
}
}
else
{
for (int index = Position + direction; index <= rookTile.Position; index++)
{
if (gameboard.Board[index] != null)
{
return(false);
}
}
}
if (gameboard.CheckDetection(Color) ||
HypotheticalMove(gameboard, Position + direction).CheckDetection(Color) || HypotheticalMove(gameboard, Position + 2 * direction).CheckDetection(Color))
{
return(false);
}
return(true);
}
if (!HasMoved && (Position == 4 || Position == 60))
{
var rookTileLeft = gameboard.Board[Position - 4];
var rookTileRight = gameboard.Board[Position + 3];
if (rookTileLeft != default && EmptyAndNoCheck(-1, rookTileLeft))
{
yield return(Position - 2);
}
if (rookTileRight != null && EmptyAndNoCheck(1, rookTileRight))
{
yield return(Position + 2);
}
}
}
protected override IEnumerable <int> GetPotentialMovements(Gameboard gameboard)
{
var returnValues = new List <(int X, int Y)>(8);
for (int index = -1; index < 2; index += 2)
{
returnValues.Add((PositionXY.X + index, PositionXY.Y - 2));
returnValues.Add((PositionXY.X + index, PositionXY.Y + 2));
returnValues.Add((PositionXY.X - 2, PositionXY.Y + index));
returnValues.Add((PositionXY.X + 2, PositionXY.Y + index));
}
return(returnValues.Where(p => p.X >= 0 && p.X < 8 && p.Y >= 0 && p.Y < 8 &&
(gameboard.Board[ConvertToOneD(p)] != null == false ||
gameboard.Board[ConvertToOneD(p)] != null == true && gameboard.Board[ConvertToOneD(p)].Color != Color))
.Select(t => ConvertToOneD(t)));
}
protected override IEnumerable <int> GetPotentialMovements(Gameboard gameboard)
{
int possibleMove = (StartPosition == Position) ? 2 : 1;
Func <int, bool> enemyPiece = position => gameboard.Board[position] != null && gameboard.Board[position].Color != Color;
if (Color == PieceColor.White)
{
//Position - 7 hack to prevent movement to the left/right
var returnValues = GetStraightLines(gameboard, possibleMove).Where(x => x < Position - 7 && gameboard.Board[x] == null);
return(returnValues.Concat(GetDiagonals(gameboard, 1).Where(x => x < Position && enemyPiece(x) || x == gameboard.EnPassantTarget)));
}
else
{
//Position + 7 hack to prevent movement to the left/right
var returnValues = GetStraightLines(gameboard, possibleMove).Where(x => x > Position + 7 && gameboard.Board[x] == null);
return(returnValues.Concat(GetDiagonals(gameboard, 1).Where(x => x > Position && enemyPiece(x) || x == gameboard.EnPassantTarget)));
}
}
protected override IEnumerable <int> GetPotentialMovements(Gameboard gameboard)
{
return(GetStraightLines(gameboard));
}
protected override IEnumerable <int> GetPotentialMovements(Gameboard gameboard)
{
return(GetDiagonals(gameboard));
}
protected override IEnumerable <int> GetPotentialMovements(Gameboard gameboard)
{
return(GetDiagonals(gameboard, 1).Concat(GetStraightLines(gameboard, 1)).Concat(GetCastlingPositions(gameboard)));
}
