// evaluate_unstoppable_pawns() scores the most advanced among the passed and
// candidate pawns. In case opponent has no pieces but pawns, this is somewhat
// related to the possibility that pawns are unstoppable.
public static Score evaluate_unstoppable_pawns(Position pos, Color us, EvalInfo ei)
{
Bitboard b = ei.pi.passed_pawns(us) | ei.pi.candidate_pawns(us);
if (0 == b || pos.non_pawn_material(Types.notColor(us)) != 0)
{
return(ScoreS.SCORE_ZERO);
}
return(Unstoppable * (Types.relative_rank_square(us, BitBoard.frontmost_sq(us, b))));
}
/// generate<CAPTURES> generates all pseudo-legal captures and queen
/// promotions. Returns a pointer to the end of the move list.
///
/// generate<QUIETS> generates all pseudo-legal non-captures and
/// underpromotions. Returns a pointer to the end of the move list.
///
/// generate<NON_EVASIONS> generates all pseudo-legal captures and
/// non-captures. Returns a pointer to the end of the move list.
///
public static int generate_captures_quiets_non_evasions(Position pos, ExtMove[] mlist, int mPos, GenType Type)
{
Debug.Assert(Type == GenTypeS.CAPTURES || Type == GenTypeS.QUIETS || Type == GenTypeS.NON_EVASIONS);
Debug.Assert(pos.checkers() == 0);
Color us = pos.side_to_move();
Bitboard target = Type == GenTypeS.CAPTURES ? pos.pieces_color(Types.notColor(us))
: Type == GenTypeS.QUIETS ? ~pos.pieces()
: Type == GenTypeS.NON_EVASIONS ? ~pos.pieces_color(us) : 0;
return(us == ColorS.WHITE ? generate_all(pos, mlist, mPos, target, ColorS.WHITE, Type)
: generate_all(pos, mlist, mPos, target, ColorS.BLACK, Type));
}
public static int generate_castling(Position pos, ExtMove[] mlist, int mPos, Color us, CheckInfo ci, CastlingRight Cr, bool Checks, bool Chess960)
{
bool KingSide = (Cr == CastlingRightS.WHITE_OO || Cr == CastlingRightS.BLACK_OO);
if (pos.castling_impeded(Cr) || 0 == pos.can_castle_castleright(Cr))
{
return(mPos);
}
// After castling, the rook and king final positions are the same in Chess960
// as they would be in standard chess.
Square kfrom = pos.king_square(us);
Square rfrom = pos.castling_rook_square(Cr);
Square kto = Types.relative_square(us, KingSide ? SquareS.SQ_G1 : SquareS.SQ_C1);
Bitboard enemies = pos.pieces_color(Types.notColor(us));
Debug.Assert(0 == pos.checkers());
Square K = Chess960 ? kto > kfrom ? SquareS.DELTA_W : SquareS.DELTA_E
: KingSide ? SquareS.DELTA_W : SquareS.DELTA_E;
for (Square s = kto; s != kfrom; s += K)
{
if ((pos.attackers_to(s) & enemies) != 0)
{
return(mPos);
}
}
// Because we generate only legal castling moves we need to verify that
// when moving the castling rook we do not discover some hidden checker.
// For instance an enemy queen in SQ_A1 when castling rook is in SQ_B1.
if (Chess960 && (BitBoard.attacks_bb_SBBPT(kto, pos.pieces() ^ BitBoard.SquareBB[rfrom], PieceTypeS.ROOK) & pos.pieces_color_piecetype(Types.notColor(us), PieceTypeS.ROOK, PieceTypeS.QUEEN)) != 0)
{
return(mPos);
}
Move m = Types.make(kfrom, rfrom, MoveTypeS.CASTLING);
if (Checks && !pos.gives_check(m, ci))
{
return(mPos);
}
mlist[mPos++].move = m;
return(mPos);
}
public EndgameBase(Color c, EndgameType E)
{
this.endgameType = E;
this.strongSide = c;
this.weakSide = Types.notColor(c);
}
