/// init() is a static member function which initializes at startup
/// the various arrays used to compute hash keys and the piece square tables.
/// The latter is a two-step operation: First, the white halves of the tables
/// are copied from PSQT[] tables. Second, the black halves of the tables are
/// initialized by flipping and changing the sign of the white scores.
internal static void init()
{
var rk = new RKISS();
for (var c = ColorC.WHITE; c <= ColorC.BLACK; c++)
{
psq[c] = new ulong[PieceTypeC.PIECE_TYPE_NB][];
for (var pt = PieceTypeC.PAWN; pt <= PieceTypeC.KING; pt++)
{
psq[c][pt] = new ulong[SquareC.SQUARE_NB];
for (var s = SquareC.SQ_A1; s <= SquareC.SQ_H8; s++)
{
psq[c][pt][s] = rk.rand();
}
}
}
for (var f = FileC.FILE_A; f <= FileC.FILE_H; f++)
{
enpassant[f] = rk.rand();
}
ulong one = 1;
for (var cr = CastleRightC.CASTLES_NONE; cr <= CastleRightC.ALL_CASTLES; cr++)
{
var b = (ulong)cr;
while (b != 0)
{
var k = castle[one << Utils.pop_lsb(ref b)];
castle[cr] ^= ((k != 0) ? k : rk.rand());
}
}
side = rk.rand();
exclusion = rk.rand();
for (var i = 0; i < PieceC.PIECE_NB; i++)
{
PieceSquareTable[i] = new int[SquareC.SQUARE_NB];
}
for (var pt = PieceTypeC.PAWN; pt <= PieceTypeC.KING; pt++)
{
Position.PieceValue[PhaseC.MG][Utils.make_piece(ColorC.BLACK, pt)] = Position.PieceValue[PhaseC.MG][pt];
Position.PieceValue[PhaseC.EG][Utils.make_piece(ColorC.BLACK, pt)] = Position.PieceValue[PhaseC.EG][pt];
var v = Utils.make_score(Position.PieceValue[PhaseC.MG][pt], Position.PieceValue[PhaseC.EG][pt]);
for (var s = SquareC.SQ_A1; s <= SquareC.SQ_H8; s++)
{
PieceSquareTable[Utils.make_piece(ColorC.WHITE, pt)][s] = (v + Utils.PSQT[pt][s]);
PieceSquareTable[Utils.make_piece(ColorC.BLACK, pt)][Utils.flip_S(s)] = -(v + Utils.PSQT[pt][s]);
}
}
}
private static ulong pick_random(RKISS rk, int booster)
{
// Values s1 and s2 are used to rotate the candidate magic of a
// quantity known to be the optimal to quickly find the magics.
int s1 = booster & 63, s2 = (booster >> 6) & 63;
ulong m = rk.rand();
m = (m >> s1) | (m << (64 - s1));
m &= rk.rand();
m = (m >> s2) | (m << (64 - s2));
return m & rk.rand();
}
private static Bitboard pick_random(Bitboard mask, RKISS rk, int booster)
{
Bitboard magic;
// Values s1 and s2 are used to rotate the candidate magic of a
// quantity known to be the optimal to quickly find the magics.
int s1 = booster & 63, s2 = (booster >> 6) & 63;
while (true)
{
magic = rk.rand();
magic = (magic >> s1) | (magic << (64 - s1));
magic &= rk.rand();
magic = (magic >> s2) | (magic << (64 - s2));
magic &= rk.rand();
if (BitCount8Bit[(mask * magic) >> 56] >= 6)
return magic;
}
}
/// init() is a static member function which initializes at startup
/// the various arrays used to compute hash keys and the piece square tables.
/// The latter is a two-step operation: First, the white halves of the tables
/// are copied from PSQT[] tables. Second, the black halves of the tables are
/// initialized by flipping and changing the sign of the white scores.
internal static void init()
{
RKISS rk = new RKISS();
for (Color c = ColorC.WHITE; c <= ColorC.BLACK; c++)
{
zobrist[c] = new Bitboard[8][];
for (PieceType pt = PieceTypeC.PAWN; pt <= PieceTypeC.KING; pt++)
{
zobrist[c][pt] = new Bitboard[64];
for (Square s = SquareC.SQ_A1; s <= SquareC.SQ_H8; s++)
{
zobrist[c][pt][s] = rk.rand();
}
}
}
for (File f = FileC.FILE_A; f <= FileC.FILE_H; f++)
zobEp[f] = rk.rand();
Bitboard one = 1;
for (int cr = CastleRightC.CASTLES_NONE; cr <= CastleRightC.ALL_CASTLES; cr++)
{
Bitboard b = (Bitboard)cr;
while (b != 0)
{
Key k = zobCastle[one << Utils.pop_1st_bit(ref b)];
zobCastle[cr] ^= ((k != 0) ? k : rk.rand());
}
}
zobSideToMove = rk.rand();
zobExclusion = rk.rand();
for (int i = 0; i < 16; i++)
{
pieceSquareTable[i] = new Score[64];
}
for (PieceType pt = PieceTypeC.PAWN; pt <= PieceTypeC.KING; pt++)
{
Score v = Utils.make_score(PieceValueMidgame[pt], PieceValueEndgame[pt]);
for (Square s = SquareC.SQ_A1; s <= SquareC.SQ_H8; s++)
{
pieceSquareTable[Utils.make_piece(ColorC.WHITE, pt)][s] = (v + Utils.PSQT[pt][s]);
pieceSquareTable[Utils.make_piece(ColorC.BLACK, pt)][Utils.flip_S(s)] = -(v + Utils.PSQT[pt][s]);
}
}
}