Python Piece.opposite_color方法代码示例

# 需要导入模块: from piece import Piece [as 别名]
# 或者: from piece.Piece import opposite_color [as 别名]
    def get_theoretical_ep_right(self, x):
        """Checks if a player could have an ep-move in theory from
        looking just at the piece positions.

        :param file:
            The file to check as a letter between `"a"` and `"h"`.

        :return:
            A boolean indicating whether the player could theoretically
            have that en-passant move.

        """
        if x < 0 or x > 7:
            raise ValueError(x)

        '''
        3 states of en-passant
        p.  pP  ..
        ..  ..  .p
        .P  ..  ..
        '''

        # Check there is a pawn on the right rank for e.p.
        y = 3 if self.fen._to_move == WHITE else 4
        x88 = X88.from_x_and_y(x, y) 

        piece = self._pieces[x88]
        if not piece:
            return False

        # If the square is not an opposite colored pawn then its not possible.
        ocolor = Piece.opposite_color(self.fen._to_move)
        if not Piece.is_klass_and_color(piece, PAWN, ocolor):
            return False

        # If the square below the pawn is not empty then it not possible.
        y = 2 if self.fen.turn == WHITE else 5
        x88 = X88.from_x_and_y(x, y) 
        if self[x88]:
            return False

        # If there is not pawn of opposite color on a neighboring file then its not possible.
        xs = [_x for _x in range(8) if _x>=0 and  _x<8 and abs(x-_x) == 1]
        for _x in xs:
            x88 = X88.from_x_and_y(_x, y) 
            piece = self._pieces[x88] 
            if Piece.is_klass_and_color(piece, PAWN, Piece.opposite_color(self.fen._to_move)):
                return True
        # Else its just not possible.
        return False

# 需要导入模块: from piece import Piece [as 别名]
# 或者: from piece.Piece import opposite_color [as 别名]
    def __init__(self, position, move):

        resulting_position = position.copy().make_move(move)
        captured = position._pieces[move.target._x88]
        piece = position._pieces[move.source._x88]
        ocolor = Piece.opposite_color(position.fen._to_move)

        # Pawn moves.
        enpassant = False
        if Piece.klass(piece) == PAWN:
            # En-passant.
            if move.target.file != move.source.file and not captured:
                enpassant = True
                captured = Piece.from_klass_and_color(PAWN, ocolor)

        # Castling.
        # TODO: Support Chess960.
        # TODO: Validate the castling move.
        if Piece.klass(piece) == KING:
            self.is_king_side_castle = move.target.x - move.source.x == 2
            self.is_queen_side_castle = move.target.x - move.source.x == -2
        else:
            self.is_king_side_castle = self.is_queen_side_castle = False

        # Checks.
        self.is_check = resulting_position.is_check()
        self.is_checkmate = resulting_position.is_checkmate()

        self.move = move
        self.piece = piece
        self.captured = captured
        self.is_enpassant = enpassant

        self._set_text(position)

# 需要导入模块: from piece import Piece [as 别名]
# 或者: from piece.Piece import opposite_color [as 别名]
    def is_king_attacked(self, color):
        """:return: Whether the king of the given color is attacked.

        :param color: `"w"` or `"b"`.
        """
        square = self.get_king(color)
        if square:
            return self.is_attacked(Piece.opposite_color(color), square)
        # XXX No king?
        else:
            return False

# 需要导入模块: from piece import Piece [as 别名]
# 或者: from piece.Piece import opposite_color [as 别名]
    def get_pseudo_legal_moves(self, source=None):
        """:yield: Pseudo legal moves in the current position.
         
        :param source: The source square to limit moves or None for
            all possible moves.
        """

        tomove = self.fen._to_move

        for x88 in [ x88 for x88 in Square._x88_squares.keys() 
            if self._pieces[x88] 
            and Piece.color(self._pieces[x88]) == tomove
            and (source is None or x88 == source._x88)]:

            piece = self._pieces[x88]
            klass = Piece.klass(piece)

            # pawn moves
            if klass == PAWN:
                single, double, capleft, capright = X88.PAWN_OFFSETS[tomove]

                # Single square ahead. Do not capture.
                offset = x88 + single
                if not self._pieces[offset]:
                    # Promotion.
                    if X88.is_backrank(offset, tomove):
                        for promote_to in Piece.promote_to:
                            yield Move.from_x88(x88, offset, promote_to)
                    else:
                        yield Move.from_x88(x88, offset)

                    # Two squares ahead. Do not capture.
                    if X88.is_secondrank(x88, tomove):
                        offset = x88 + double
                        if not self._pieces[offset]:
                            yield Move.from_x88(x88, offset)

                # Pawn captures.
                for cap in [capleft, capright]:
                    offset = x88 + cap
                    if offset & X88.X88:
                        continue
                    target = self._pieces[offset]
                    if target and Piece.color(target) != tomove:
                       # Promotion.
                        if X88.is_backrank(offset, tomove):
                            for promote_to in Piece.promote_to:
                                yield Move.from_x88(x88, offset, promote_to)
                        else:
                            yield Move.from_x88(x88, offset)
                   # En-passant.
                    elif not target and offset == self.fen._ep:
                        yield Move.from_x88(target, self.fen._ep)
            
            #piece moves
            else:
                # for each a direction a piece moves in
                for offset in X88.PIECE_OFFSETS[Piece.klass(piece)]:

                    t_x88 = x88 + offset

                    # while we do not fall off the board
                    while not t_x88 & 0x88:
                        
                        # if there was not piece to attack then yield a quiet move
                        if not self._pieces[t_x88]:
                            yield Move.from_x88(x88, t_x88)
                            # do not break out

                        # else there is a piece there
                        else:
                            # if we can attack generate a move
                            if Piece.color(self._pieces[t_x88]) != tomove:
                                yield Move.from_x88(x88, t_x88)
                            # we hit something so break out
                            break

                        # Knight and king do not go multiple times in their direction.
                        if klass in [KNIGHT, KING]:
                            break

                        # travel down the board in the direction
                        t_x88 += offset


        # castling moves
        opponent = Piece.opposite_color(tomove)
        ok = True

        # get possible castling for the side to move
        for castle in [c for c in self.fen._castle_rights if Piece.color(c) == tomove]:

            (square, enum), _ = Piece.castle_squares[castle]
            king = Square(square)

            if Piece.klass(castle) == KING:
                direc = 1
            else:
                direc = -1

#.........这里部分代码省略.........

# 需要导入模块: from piece import Piece [as 别名]
# 或者: from piece.Piece import opposite_color [as 别名]
    def make_move(self, move, validate=True):
        """Makes a move.

        :param move:
            The move to make.
        :param validate:
            Defaults to `True`. Whether the move should be validated.

        :return:
            Making a move changes the position object. The same
            (changed) object is returned for chainability.

        :raise MoveError:
            If the validate parameter is `True` and the move is not
            legal in the position.
        """

        #if validate:
        if validate:
            if move not in self.get_legal_moves(source=move.source):
                raise MoveError(
                    "%s is not a legal move in the position %s." % (move, self.fen))

        piece = self._pieces[move._source_x88]
        capture = self._pieces[move._target_x88]
        target = move.target
        source = move.source

        # Move the piece.
        self._pieces[move._target_x88] = piece
        self._pieces[move._source_x88] = None

        # It is the next players turn.
        ocolor = Piece.opposite_color(self.fen._to_move)
        self.fen._to_move = ocolor

        # Pawn moves.
        self._ep = None
        if Piece.klass(piece) == PAWN:

            # En-passant.
            if target.x != source.x and not capture:
                offset = 16 if self.fen._to_move == WHITE else -16
                self._pieces[target.x88() + offset] = None
                capture = True

            # If big pawn move, set the en-passant file.
            if abs(target.y - source.y) == 2:
                if self.get_theoretical_ep_right(target.x):
                    self._ep = move.target

        # Promotion.
        if move.promotion:
            self._pieces[move.target._x88] = move.promotion

        # Potential castling.
        if Piece.klass(piece) == KING:
            steps = move.target.x - move.source.x
            if abs(steps) == 2:
                # Queen-side castling.
                if steps == -2:
                    rook_target = move.target.x88 + 1
                    rook_source = move.target.x88 - 2
                # King-side castling.
                else:
                    rook_target = move.target.x88 - 1
                    rook_source = move.target.x88 + 1
                self._pieces[rook_target] = self._pieces[rook_source]
                self._pieces[rook_source] = None

        # Update castling rights.
        for klass in self.fen._castle_rights:
            if not self.get_theoretical_castling_right(klass):
                self.fen._castle_rights.remove(klass)
                # XXX Castling rights can only be removed 
                #self.set_castling_right(klass, False)


        # Increment the 50 move half move counter.
        if Piece.klass(piece) == PAWN or capture:
            self.fen._fifty_move = 0
        else:
            self.fen._fifty_move += 1

        # Increment the move number.
        if self.fen._to_move == WHITE:
            self.fen._full_move += 1
        
        return self