private static void generate_castle(
int Side,
bool Checks,
Position pos,
MoveStack[] ms,
ref int mpos,
int us)
{
if (pos.castle_impeded(us, Side) || (pos.can_castle_CR(Utils.make_castle_right(us, Side)) == 0))
{
return;
}
// After castling, the rook and king final positions are the same in Chess960
// as they would be in standard chess.
var kfrom = pos.king_square(us);
var rfrom = pos.castle_rook_square(us, Side);
var kto = Utils.relative_square(us, Side == CastlingSideC.KING_SIDE ? SquareC.SQ_G1 : SquareC.SQ_C1);
var enemies = pos.pieces_C(us ^ 1);
Debug.Assert(!pos.in_check());
int K = pos.chess960 ? kto > kfrom ? -1 : 1 : Side == CastlingSideC.KING_SIDE ? -1 : 1;
for (Square s = kto; s != kfrom; s += (Square)K)
{
if ((pos.attackers_to(s) & enemies) != 0)
{
return;
}
}
// 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 (pos.chess960 && ((pos.attackers_to(kto, Utils.xor_bit(pos.occupied_squares, rfrom)) & enemies) != 0))
{
return;
}
var m = Utils.make(kfrom, rfrom, MoveTypeC.CASTLING);
if (Checks)
{
var ci = CheckInfoBroker.GetObject();
ci.CreateCheckInfo(pos);
var givesCheck = pos.move_gives_check(m, ci);
CheckInfoBroker.Free();
if (!givesCheck)
{
return;
}
}
ms[mpos++].move = m;
}
private static void generate_castle(CastlingSide Side, bool OnlyChecks, Position pos, MoveStack[] ms, ref int mpos, Color us)
{
if (pos.castle_impeded(us, Side) || (pos.can_castle_CR(Utils.make_castle_right(us, Side))==0) )
return;
// 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.castle_rook_square(us, Side);
Square kto = Utils.relative_square(us, Side == CastlingSideC.KING_SIDE ? SquareC.SQ_G1 : SquareC.SQ_C1);
Bitboard enemies = pos.pieces_C(us ^ 1);
Debug.Assert(!pos.in_check());
for (Square s = Math.Min(kfrom, kto), e = Math.Max(kfrom, kto); s <= e; s++)
if (s != kfrom // We are not in check
&& ((pos.attackers_to(s) & enemies) != 0))
return;
// 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 (pos.chess960
&& ((pos.attackers_to(kto, Utils.xor_bit(pos.occupied_squares, rfrom)) & enemies) != 0))
return;
Move m = Utils.make_castle(kfrom, rfrom);
if (OnlyChecks)
{
CheckInfo ci = CheckInfoBroker.GetObject();
ci.CreateCheckInfo(pos);
bool givesCheck = pos.move_gives_check(m, ci);
CheckInfoBroker.Free();
if (!givesCheck) return;
}
ms[mpos++].move = m;
}
/// flip() flips position with the white and black sides reversed. This
/// is only useful for debugging especially for finding evaluation symmetry bugs.
internal void flip()
{
// Make a copy of current position before to start changing
Position pos = new Position(this);
clear();
sideToMove = pos.sideToMove ^ 1;
thisThread = pos.this_thread();
nodes = pos.nodes;
chess960 = pos.chess960;
startPosPly = pos.startpos_ply_counter();
for (Square s = SquareC.SQ_A1; s <= SquareC.SQ_H8; s++)
if (!pos.is_empty(s))
put_piece((pos.piece_on(s) ^ 8), Utils.flip_S(s));
if (pos.can_castle_CR(CastleRightC.WHITE_OO) != 0)
set_castle_right(ColorC.BLACK, Utils.flip_S(pos.castle_rook_square(ColorC.WHITE, CastlingSideC.KING_SIDE)));
if (pos.can_castle_CR(CastleRightC.WHITE_OOO) != 0)
set_castle_right(ColorC.BLACK, Utils.flip_S(pos.castle_rook_square(ColorC.WHITE, CastlingSideC.QUEEN_SIDE)));
if (pos.can_castle_CR(CastleRightC.BLACK_OO) != 0)
set_castle_right(ColorC.WHITE, Utils.flip_S(pos.castle_rook_square(ColorC.BLACK, CastlingSideC.KING_SIDE)));
if (pos.can_castle_CR(CastleRightC.BLACK_OOO) != 0)
set_castle_right(ColorC.WHITE, Utils.flip_S(pos.castle_rook_square(ColorC.BLACK, CastlingSideC.QUEEN_SIDE)));
if (pos.st.epSquare != SquareC.SQ_NONE)
st.epSquare = Utils.flip_S(pos.st.epSquare);
// Checkers
st.checkersBB = attackers_to(king_square(sideToMove)) & pieces_C(Utils.flip_C(sideToMove));
// Hash keys
st.key = compute_key();
st.pawnKey = compute_pawn_key();
st.materialKey = compute_material_key();
// Incremental scores
st.psqScore = compute_psq_score();
// Material
st.npMaterialWHITE = compute_non_pawn_material(ColorC.WHITE);
st.npMaterialBLACK = compute_non_pawn_material(ColorC.BLACK);
Debug.Assert(pos_is_ok());
}
