Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2015-2017 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
if ( distance(ksq[WHITE], ksq[BLACK]) <= 1
|| ksq[WHITE] == psq
|| ksq[BLACK] == psq
- || (us == WHITE && (StepAttacksBB[PAWN][psq] & ksq[BLACK])))
+ || (us == WHITE && (PawnAttacks[WHITE][psq] & ksq[BLACK])))
result = INVALID;
// Immediate win if a pawn can be promoted without getting captured
else if ( us == WHITE
&& rank_of(psq) == RANK_7
- && ksq[us] != psq + DELTA_N
- && ( distance(ksq[~us], psq + DELTA_N) > 1
- || (StepAttacksBB[KING][ksq[us]] & (psq + DELTA_N))))
+ && ksq[us] != psq + NORTH
+ && ( distance(ksq[~us], psq + NORTH) > 1
+ || (PseudoAttacks[KING][ksq[us]] & (psq + NORTH))))
result = WIN;
// Immediate draw if it is a stalemate or a king captures undefended pawn
else if ( us == BLACK
- && ( !(StepAttacksBB[KING][ksq[us]] & ~(StepAttacksBB[KING][ksq[~us]] | StepAttacksBB[PAWN][psq]))
- || (StepAttacksBB[KING][ksq[us]] & psq & ~StepAttacksBB[KING][ksq[~us]])))
+ && ( !(PseudoAttacks[KING][ksq[us]] & ~(PseudoAttacks[KING][ksq[~us]] | PawnAttacks[~us][psq]))
+ || (PseudoAttacks[KING][ksq[us]] & psq & ~PseudoAttacks[KING][ksq[~us]])))
result = DRAW;
// Position will be classified later
const Result Bad = (Us == WHITE ? DRAW : WIN);
Result r = INVALID;
- Bitboard b = StepAttacksBB[KING][ksq[Us]];
+ Bitboard b = PseudoAttacks[KING][ksq[Us]];
while (b)
r |= Us == WHITE ? db[index(Them, ksq[Them] , pop_lsb(&b), psq)]
if (Us == WHITE)
{
if (rank_of(psq) < RANK_7) // Single push
- r |= db[index(Them, ksq[Them], ksq[Us], psq + DELTA_N)];
+ r |= db[index(Them, ksq[Them], ksq[Us], psq + NORTH)];
if ( rank_of(psq) == RANK_2 // Double push
- && psq + DELTA_N != ksq[Us]
- && psq + DELTA_N != ksq[Them])
- r |= db[index(Them, ksq[Them], ksq[Us], psq + DELTA_N + DELTA_N)];
+ && psq + NORTH != ksq[Us]
+ && psq + NORTH != ksq[Them])
+ r |= db[index(Them, ksq[Them], ksq[Us], psq + NORTH + NORTH)];
}
return result = r & Good ? Good : r & UNKNOWN ? UNKNOWN : Bad;