/// <summary>
/// 仅从偏移量角度来筛选出不合法走子,
/// 不考虑子所在的位置, 不考虑兵的前进后退.
/// </summary>
/// <param name="delta">偏移量</param>
/// <param name="piece">棋子种类</param>
/// <returns></returns>
public static Boolean is_valid(CoordinateDelta delta, PieceType piece)
{
switch (piece)
{
default:
throw new ArgumentOutOfRangeException("棋子种类越界!");
case PieceType.ADVISOR:
if (delta.abs().Equals(new CoordinateDelta(1, 1)))
{
return(true);
}
return(false);
case PieceType.BISHOP:
if (delta.abs().Equals(new CoordinateDelta(2, 2)))
{
return(true);
}
return(false);
case PieceType.CANNON:
case PieceType.ROOK:
if (delta.x == 0 || delta.y == 0)
{
return(true);
}
return(false);
case PieceType.KING:
case PieceType.PAWN:
if (delta.abs().Equals(new CoordinateDelta(1, 0)) ||
delta.abs().Equals(new CoordinateDelta(0, 1)))
{
return(true);
}
return(false);
case PieceType.KNIGHT:
if (delta.abs().Equals(new CoordinateDelta(2, 1)) ||
delta.abs().Equals(new CoordinateDelta(1, 2)))
{
return(true);
}
return(false);
}
}
/// <summary>
/// 判断忽略棋规的情况下棋步是否合法
/// </summary>
/// <param name="start">起始坐标</param>
/// <param name="end">终止坐标</param>
private Boolean is_raw_move(Coordinate start, Coordinate end)
{
ChessColour player = this.current_player;
PieceType piece = this[start].type;
CoordinateDelta delta = end - start;
switch (piece)
{
default:
throw new ArgumentOutOfRangeException("棋子种类越界!");
case PieceType.ADVISOR:
case PieceType.KING:
if (ChessPosition.is_inside_castle(end, player))
{
return(true);
}
return(false);
case PieceType.BISHOP:
if (ChessPosition.is_castle_side(end, player))
{
if (this.check_bishop_eye(start, delta))
{
return(true);
}
}
return(false);
case PieceType.CANNON:
if (this[end].type == PieceType.NONE)
{
if (this.count_piece(start, delta) == 0)
{
return(true);
}
return(false);
}
if (this.count_piece(start, delta) == 1)
{
return(true);
}
return(false);
case PieceType.KNIGHT:
if (this.check_knight_leg(start, delta))
{
return(true);
}
return(false);
case PieceType.PAWN:
if (ChessPosition.get_move_direction(delta, player) ==
MoveDirection.BACKWARD)
{
return(false);
}
if (ChessPosition.is_castle_side(start, player))
{
if (!delta.abs().Equals(new CoordinateDelta(0, 1)))
{
return(false);
}
}
return(true);
case PieceType.ROOK:
if (this.count_piece(start, delta) == 0)
{
return(true);
}
return(false);
}
}