/// <summary>
/// Calculate the actual actions available for a Chess Piece at a set of coordinates.
/// </summary>
/// <param name="x">The number of squares right of the bottom left square</param>
/// <param name="y">The number of squares above the bottom left square</param>
/// <param name="ignoreCheck">Do not check for threats to the king</param>
/// <param name="attackActions">Calculate attacks</param>
/// <param name="moveActions">Calculate movement</param>
/// <param name="boardArray">An optional substitute board</param>
/// <returns>A list of points that can be moved to</returns>
public IEnumerable <Point> PieceActions(int x, int y, bool ignoreCheck = false, bool attackActions = true, bool moveActions = true, ChessPiece[,] boardArray = null)
{
if (boardArray == null)
{
boardArray = this.boardArray;
}
bool[,] legalActions = new bool[boardArray.GetLength(0), boardArray.GetLength(1)];
List <Point> availableActions = new List <Point>();
ChessPiece movingPeice = boardArray[x, y];
if (attackActions)
{
foreach (Point[] direction in movingPeice.AvailableAttacks)
{
foreach (Point attackPoint in direction)
{
Point adjustedPoint = new Point(attackPoint.x + x, attackPoint.y + y);
if (ValidatePoint(adjustedPoint))
{
if (boardArray[adjustedPoint.x, adjustedPoint.y] != null &&
boardArray[adjustedPoint.x, adjustedPoint.y].Player ==
movingPeice.Player)
{
break;
}
if (boardArray[adjustedPoint.x, adjustedPoint.y] != null)
{
AddMove(availableActions, new Point(x, y), adjustedPoint, ignoreCheck);
break;
}
}
}
}
}
if (moveActions)
{
foreach (Point[] direction in movingPeice.AvailableMoves)
{
foreach (Point movePoint in direction)
{
Point adjustedPoint = new Point(movePoint.x + x, movePoint.y + y);
if (ValidatePoint(adjustedPoint))
{
if (boardArray[adjustedPoint.x, adjustedPoint.y] != null)
{
break;
}
AddMove(availableActions, new Point(x, y), adjustedPoint, ignoreCheck);
}
}
}
}
if (movingPeice is King && ((King)movingPeice).CanCastle)
{
int rookX = 0;
if (boardArray[rookX, y] is Rook && ((Rook)boardArray[rookX, y]).CanCastle)
{
bool missedCondition = false;
foreach (int rangeX in Enumerable.Range(rookX + 1, Math.Abs(rookX - x) - 1))
{
if (boardArray[rangeX, y] != null)
{
missedCondition = true;
}
// TODO: Validate that the king won't move through check
}
// TODO: Validate that king isn't currently in check
missedCondition = missedCondition || KingInCheck(movingPeice.Player);
if (!missedCondition)
{
AddMove(availableActions, new Point(x, y), new Point(x - 2, y), ignoreCheck);
}
}
rookX = COLUMNS - 1;
if (boardArray[rookX, y] is Rook && ((Rook)boardArray[rookX, y]).CanCastle)
{
bool missedCondition = false;
foreach (int rangeX in Enumerable.Range(x + 1, Math.Abs(rookX - x) - 1))
{
if (boardArray[rangeX, y] != null)
{
missedCondition = true;
}
// TODO: Validate that the king won't move through check
}
// TODO: Validate that king isn't currently in check
missedCondition = missedCondition || KingInCheck(movingPeice.Player);
if (!missedCondition)
{
AddMove(availableActions, new Point(x, y), new Point(x + 2, y), ignoreCheck);
}
}
}
if (movingPeice is Pawn)
{
Pawn pawn = (Pawn)movingPeice;
int flipDirection = 1;
if (pawn.Player == 1)
{
flipDirection = -1;
}
if (pawn.CanEnPassantLeft)
{
Point attackPoint;
attackPoint = ChessPiece.GetDiagnalMovementArray(1, DiagnalDirection.FORWARD_LEFT)[0];
attackPoint.y *= flipDirection;
attackPoint.y += y;
attackPoint.x += x;
if (ValidatePoint(attackPoint))
{
AddMove(availableActions, new Point(x, y), attackPoint, ignoreCheck);
}
}
if (pawn.CanEnPassantRight)
{
Point attackPoint;
attackPoint = ChessPiece.GetDiagnalMovementArray(1, DiagnalDirection.FORWARD_RIGHT)[0];
attackPoint.y *= flipDirection;
attackPoint.y += y;
attackPoint.x += x;
if (ValidatePoint(attackPoint))
{
AddMove(availableActions, new Point(x, y), attackPoint, ignoreCheck);
}
}
}
return(availableActions);
}