def undo_update(self, board):
self.undo(board)
color = self.color
other = next_color(color)
dest = self._destination
origin = self._origin
piece = self.piece
flags = self.flags
captured = self.captured
en_passant_square = dest + (N if color == BLACK else S)
# castling
if piece == KING:
if flags & KINGSIDE:
castling_origin = dest + E
castling_dest = dest + W
board.values[castling_dest] = 0
board.values[castling_origin] = board.piece_value(
ROOK, color, castling_origin)
elif flags & QUEENSIDE:
castling_origin = dest + W + W
castling_dest = dest + E
board.values[castling_dest] = 0
board.values[castling_origin] = board.piece_value(
ROOK, color, castling_origin)
board.values[origin] = board.piece_value(piece, color, dest)
if captured:
if flags & EN_PASSANT:
board.values[en_passant_square] = board.piece_value(
PAWN, other, en_passant_square)
else:
board.values[dest] = board.piece_value(captured, other, dest)
else:
board.values[dest] = 0
def undo(self, board):
current = self.color
dest = self._destination
origin = self._origin
piece = self.piece
flags = self.flags
captured = self.captured
en_passant_square = dest + (N if current == BLACK else S)
board.current_color = current
other = next_color(current)
if current == BLACK:
board.moves -= 1
board.half_moves = self.half_moves
board.en_passant_square = self.previous_en_passant
board.castling[WHITE] = self.white_castling
board.castling[BLACK] = self.black_castling
if piece == KING:
board.kings[current] = origin
if flags & KINGSIDE:
castling_origin = dest + E
castling_dest = dest + W
rook_piece = board.pieces[castling_dest]
board.remove(castling_dest)
board.add(rook_piece, current, castling_origin)
elif flags & QUEENSIDE:
castling_origin = dest + W + W
castling_dest = dest + E
rook_piece = board.pieces[castling_dest]
board.remove(castling_dest)
board.add(rook_piece, current, castling_origin)
board.remove(dest)
board.add(piece, current, origin)
if captured:
if flags & EN_PASSANT:
board.add(PAWN, other, en_passant_square)
else:
board.add(captured, other, dest)
board.hash = self.previous_hash
def do(self, board):
current = self.color
other = next_color(current)
piece = board.pieces[self._origin]
color = board.colors[self._origin]
other_piece = board.pieces[self._destination]
origin = self._origin
dest = self._destination
flags = self.flags
en_passant_square = dest + (N if current == BLACK else S)
board.remove(origin)
board.remove(dest)
board.add(piece, color, dest)
# En passant
if flags & EN_PASSANT:
board.remove(dest + (N if current == BLACK else S))
# Promotion
if flags & PROMOTION:
board.remove(dest)
board.add(self.promotion, color, dest)
if piece == KING:
board.kings[current] = dest
# Castling
if flags & KINGSIDE:
castling_origin = dest + E
castling_dest = dest + W
piece = board.pieces[castling_origin]
board.remove(castling_origin)
board.add(piece, color, castling_dest)
elif flags & QUEENSIDE:
castling_origin = dest + W + W
castling_dest = dest + E
piece = board.pieces[castling_origin]
board.remove(castling_origin)
board.add(piece, color, castling_dest)
board.castling[current] = 0
# if move rook, disable castling:
if board.castling[current] and piece == ROOK:
if current == WHITE:
if board.castling[WHITE] & KINGSIDE and origin == H1:
board.castling[WHITE] ^= KINGSIDE
elif board.castling[WHITE] & QUEENSIDE and origin == A1:
board.castling[WHITE] ^= KINGSIDE
if current == BLACK:
if board.castling[BLACK] & KINGSIDE and origin == H7:
board.castling[BLACK] ^= KINGSIDE
elif board.castling[BLACK] & QUEENSIDE and origin == A7:
board.castling[BLACK] ^= KINGSIDE
# if capture rook, disable castling
if board.castling[other] and other_piece == ROOK:
if current == WHITE:
if board.castling[BLACK] & KINGSIDE and dest == H1:
board.castling[BLACK] ^= KINGSIDE
elif board.castling[BLACK] & QUEENSIDE and dest == A1:
board.castling[BLACK] ^= KINGSIDE
if current == BLACK:
if board.castling[WHITE] & KINGSIDE and dest == H7:
board.castling[WHITE] ^= KINGSIDE
elif board.castling[WHITE] & QUEENSIDE and dest == A7:
board.castling[WHITE] ^= KINGSIDE
board.hash ^= zobrist_castling[self.castle()]
board.hash ^= zobrist_castling[board.castle()]
# big pawn
if board.en_passant_square != EMPTY:
board.hash ^= zobrist_en_passant[board.en_passant_square]
if flags & BIG_PAWN:
board.en_passant_square = en_passant_square
board.hash ^= zobrist_en_passant[board.en_passant_square]
else:
board.en_passant_square = EMPTY
# Update half move counter
if piece == PAWN or (flags & (CAPTURE | EN_PASSANT)):
board.half_moves = 0
else:
board.half_moves += 1
if current == BLACK:
board.moves += 1
board.current_color = next_color(current)
board.hash ^= zobrist_color
def in_check(self, color):
if color == COLOR_EMPTY:
color = self.current_color
if self.kings[color] == EMPTY:
return False
return self.attacked(self.kings[color], next_color(color))
def generate_moves(self, legal, square, color):
moves = []
current = color
first = A8
last = H1
single = 0
if current == COLOR_EMPTY:
current = self.current_color
other = next_color(current)
if is_square(square):
first = square
last = square
single = 1
for i in range(first, last + 1):
if is_not_square(i):
i = i + 7
continue
if self.colors[i] != current:
continue
piece = self.pieces[i]
if piece == PAWN:
# 1 step forward
square = i + PAWN_OFFSETS[current][0]
if not self.pieces[square]:
moves.append(Move(self, current, i, square, NORMAL))
# 2 steps forward
square = i + PAWN_OFFSETS[current][1]
if (rank(i) == SECOND_RANK[current] and
not self.pieces[square]):
moves.append(Move(self, current, i, square, BIG_PAWN))
# Captures
for j in range(2, 4):
square = i + PAWN_OFFSETS[current][j]
if is_not_square(square):
continue
if self.pieces[square] and self.colors[square] == other:
moves.append(Move(self, current, i, square, CAPTURE))
elif square == self.en_passant_square:
moves.append(
Move(self, current, i, square, EN_PASSANT))
else:
for j in range(0, PIECE_OFFSET_SIZE[piece]):
offset = PIECE_OFFSET[piece][j]
square = i
while True:
square += offset
if is_not_square(square):
break
if not self.pieces[square]:
moves.append(
Move(self, current, i, square, NORMAL))
else:
if self.colors[square] == current:
break
moves.append(
Move(self, current, i, square, CAPTURE))
break
# Stop after first for king and knight
if (piece == KING or piece == KNIGHT):
break
# Castling
if ((not single or last == self.kings[current]) and
self.kings[current] != EMPTY):
if self.castling[current] & KINGSIDE:
origin = self.kings[current]
dest = origin + E + E
if (not self.pieces[origin + E] and
not self.pieces[dest] and
not self.attacked(origin, other) and
not self.attacked(origin + E, other) and
not self.attacked(dest, other)):
moves.append(Move(self, current, origin, dest, KINGSIDE))
if self.castling[current] & QUEENSIDE:
origin = self.kings[current]
dest = origin + W + W
if (not self.pieces[origin + W] and
not self.pieces[origin + W + W] and
not self.pieces[origin + W + W + W] and
not self.pieces[dest] and
not self.attacked(origin, other) and
not self.attacked(origin + W, other) and
not self.attacked(dest, other)):
moves.append(Move(self, current, origin, dest, QUEENSIDE))
if not legal:
return moves
legal_moves = []
for move in moves:
move.do(self)
if not self.in_check(current):
legal_moves.append(move)
#else:
# self.display()
move.undo(self)
return legal_moves
