def is_in_check(board_state):
if board_state.turn == TURN_WHITE:
king = msb(board_state.occupied_w & board_state.kings)
return bool(_attackers_mask(board_state, TURN_BLACK, king, board_state.occupied))
else:
king = msb(board_state.occupied_b & board_state.kings)
return bool(_attackers_mask(board_state, TURN_WHITE, king, board_state.occupied))
def _is_safe(board_state, king, blockers, move):
if move.from_square == king:
if is_castling(board_state, move):
return True
else:
return not bool(_attackers_mask(board_state, not board_state.turn, move.to_square, board_state.occupied))
elif is_en_passant(board_state, move):
return (pin_mask(board_state, board_state.turn, move.from_square) & BB_SQUARES[move.to_square] and
not _ep_skewered(board_state, king, move.from_square))
else:
return (not blockers & BB_SQUARES[move.from_square] or
BB_RAYS[move.from_square, move.to_square] & BB_SQUARES[king])
def generate_legal_moves(board_state, from_mask=BB_ALL, to_mask=BB_ALL):
if board_state.turn == TURN_WHITE:
king = msb(board_state.kings & board_state.occupied_w)
else:
king = msb(board_state.kings & board_state.occupied_b)
blockers = _slider_blockers(board_state, king)
checkers = _attackers_mask(board_state, not board_state.turn, king, board_state.occupied)
#If in check
if checkers:#If no moves are found it needs to be passed along that the board is in check, so it doesn't need to be computed again directly afterwards
for move in _generate_evasions(board_state, king, checkers, from_mask, to_mask):
if _is_safe(board_state, king, blockers, move):
yield move
else:#If no moves are found it needs to be passed along that the board is not in check, so it doesn't need to be computed again directly afterwards
for move in generate_pseudo_legal_moves(board_state, from_mask, to_mask):
if _is_safe(board_state, king, blockers, move):
yield move