protected virtual bool IsValidLinearMovement(Square source, Square target)
{
var allowedSquares = new List <Square>();
var rowDelta = target.Row - source.Row;
var columnDelta = target.Column - source.Column;
var rowIncrement = ((rowDelta < 0) ? -1 : (rowDelta > 0) ? 1 : 0);
var columnIncrement = ((columnDelta < 0) ? -1 : (columnDelta > 0) ? 1 : 0);
var nextPosition = source.Move(1, rowIncrement, columnIncrement);
while (nextPosition != null && !nextPosition.Equals(target))
{
allowedSquares.Add(nextPosition);
nextPosition = nextPosition.Move(1, rowIncrement, columnIncrement);
}
return(!allowedSquares.Any(s => s.Piece != null));
}
protected IEnumerable<Square> MoveUntilObstruction(Square from, MoveDirection dir)
{
var target = from.Move(dir);
bool last = false;
var player = this.Board[from].Player;
while (target.HasValue && (this.Board[target.Value] == null || this.Board[target.Value].Player != player) && !last)
{
yield return target.Value;
last = this.Board[target.Value] != null;
target = target.Move(dir);
}
}
public IList<Piece> GetAttackers(Square square, PlayerColor attacker)
{
var ret = new List<Piece>();
//Find adjacent king
if (this[attacker].First(i => i is King).Square.IsAdjacent(square))
ret.Add(this[attacker].First(i => i is King));
//Find attacking Pawn
foreach (var dir in Pawn.GetAttackingDirection(attacker).GetDiagonals())
{
var pawn = this[square.Move(dir)] as Pawn;
if (pawn != null && pawn.Player == attacker)
ret.Add(pawn);
}
var opponents = this[attacker].Where(i => !(i is King));
var moves = opponents.Where(i => !(i is King || i is Pawn)).SelectMany(o => o.GetValidMoves().Where(i => i.Target == square && i.CanCapture));
ret.AddRange(moves.Select(i => i.Piece));
return ret;
}