sync_cout;
if (move)
- {
- Position p(*this);
- cout << "\nMove is: " << (sideToMove == BLACK ? ".." : "") << move_to_san(p, move);
- }
+ cout << "\nMove is: " << (sideToMove == BLACK ? ".." : "")
+ << move_to_san(*const_cast<Position*>(this), move);
for (Square sq = SQ_A1; sq <= SQ_H8; sq++)
if (piece_on(sq) != NO_PIECE)
for (int i = 0; i < 8; i++)
for (int j = 0; j < 16; j++)
pieceList[0][i][j] = pieceList[1][i][j] = SQ_NONE;
-
- for (Square sq = SQ_A1; sq <= SQ_H8; sq++)
- board[sq] = NO_PIECE;
}
/// Position::is_draw() tests whether the position is drawn by material,
/// repetition, or the 50 moves rule. It does not detect stalemates, this
/// must be done by the search.
-template<bool SkipRepetition>
+template<bool CheckRepetition, bool CheckThreeFold>
bool Position::is_draw() const {
- // Draw by material?
if ( !pieces(PAWN)
&& (non_pawn_material(WHITE) + non_pawn_material(BLACK) <= BishopValueMg))
return true;
- // Draw by the 50 moves rule?
if (st->rule50 > 99 && (!in_check() || MoveList<LEGAL>(*this).size()))
return true;
- // Draw by repetition?
- if (!SkipRepetition)
+ if (CheckRepetition)
{
int i = 4, e = std::min(st->rule50, st->pliesFromNull);
{
StateInfo* stp = st->previous->previous;
- do {
+ for (int cnt = 0; i <= e; i += 2)
+ {
stp = stp->previous->previous;
- if (stp->key == st->key)
+ if (stp->key == st->key && (!CheckThreeFold || ++cnt >= 2))
return true;
-
- i +=2;
-
- } while (i <= e);
+ }
}
}
}
// Explicit template instantiations
-template bool Position::is_draw<false>() const;
-template bool Position::is_draw<true>() const;
+template bool Position::is_draw<true, true>() const;
+template bool Position::is_draw<true, false>() const;
+template bool Position::is_draw<false,false>() const;
/// Position::flip() flips position with the white and black sides reversed. This