Public Class Rook
    Inherits Piece
    Public Overrides Function CalculateMove(CurrentBoard As Board, SourcePoint As Point) As List(Of Point)
        Dim DestinationLst As New List(Of Point)
        Dim PDirections() As Point = {
            New Point(-1, 0),  'N
            New Point(0, 1),   'E
            New Point(1, 0),   'S
            New Point(0, -1)  'W
        }
        For Each Direction In PDirections
            Dim NextDestination As New Point(SourcePoint.X + Direction.X, SourcePoint.Y + Direction.Y)
            While CheckWithinArray(NextDestination)
                If CurrentBoard.PieceBoard(SourcePoint.X, SourcePoint.Y) > 0 Then
                    If CurrentBoard.PieceBoard(NextDestination.X, NextDestination.Y) = 0 Then
                        DestinationLst.Add(NextDestination)
                    ElseIf CurrentBoard.PieceBoard(NextDestination.X, NextDestination.Y) < 0 Then
                        DestinationLst.Add(NextDestination)
                        Exit While
                    Else
                        Exit While
                    End If
                ElseIf CurrentBoard.PieceBoard(SourcePoint.X, SourcePoint.Y) < 0 Then
                    If CurrentBoard.PieceBoard(NextDestination.X, NextDestination.Y) = 0 Then
                        DestinationLst.Add(NextDestination)
                    ElseIf CurrentBoard.PieceBoard(NextDestination.X, NextDestination.Y) > 0 Then
                        DestinationLst.Add(NextDestination)
                        Exit While
                    Else
                        Exit While
                    End If
                End If
                NextDestination.X += Direction.X
                NextDestination.Y += Direction.Y
            End While
        Next
        Return DestinationLst
    End Function
End Class