private int kingSafetyKPPart(Position pos)
{
ulong key = pos.pawnZobristHash() ^ pos.kingZobristHash();
KingSafetyHashData ksh = kingSafetyHash[(int)key & (kingSafetyHash.Length - 1)];
if (ksh.key != key) {
int score = 0;
ulong wPawns = pos.pieceTypeBB[Piece.WPAWN];
ulong bPawns = pos.pieceTypeBB[Piece.BPAWN];
{
int safety = 0;
int halfOpenFiles = 0;
if (Position.getY(pos.wKingSq) < 2) {
ulong shelter = 1UL << Position.getX(pos.wKingSq);
shelter |= ((shelter & BitBoard.maskBToHFiles) >> 1) |
((shelter & BitBoard.maskAToGFiles) << 1);
shelter <<= 8;
safety += 3 * BITS.bitCount(wPawns & shelter);
safety -= 2 * BITS.bitCount(bPawns & (shelter | (shelter << 8)));
shelter <<= 8;
safety += 2 * BITS.bitCount(wPawns & shelter);
shelter <<= 8;
safety -= BITS.bitCount(bPawns & shelter);
ulong wOpen = BitBoard.southFill(shelter) & (~BitBoard.southFill(wPawns)) & 0xff;
if (wOpen != 0) {
halfOpenFiles += 25 * BITS.bitCount(wOpen & 0xe7);
halfOpenFiles += 10 * BITS.bitCount(wOpen & 0x18);
}
ulong bOpen = BitBoard.southFill(shelter) & (~BitBoard.southFill(bPawns)) & 0xff;
if (bOpen != 0) {
halfOpenFiles += 25 * BITS.bitCount(bOpen & 0xe7);
halfOpenFiles += 10 * BITS.bitCount(bOpen & 0x18);
}
safety = Math.Min(safety, 8);
}
int kSafety = (safety - 9) * 15 - halfOpenFiles;
score += kSafety;
}
{
int safety = 0;
int halfOpenFiles = 0;
if (Position.getY(pos.bKingSq) >= 6) {
ulong shelter = 1UL << (56 + Position.getX(pos.bKingSq));
shelter |= ((shelter & BitBoard.maskBToHFiles) >> 1) |
((shelter & BitBoard.maskAToGFiles) << 1);
shelter >>= 8;
safety += 3 * BITS.bitCount(bPawns & shelter);
safety -= 2 * BITS.bitCount(wPawns & (shelter | (shelter >> 8)));
shelter >>= 8;
safety += 2 * BITS.bitCount(bPawns & shelter);
shelter >>= 8;
safety -= BITS.bitCount(wPawns & shelter);
ulong wOpen = BitBoard.southFill(shelter) & (~BitBoard.southFill(wPawns)) & 0xff;
if (wOpen != 0) {
halfOpenFiles += 25 * BITS.bitCount(wOpen & 0xe7);
halfOpenFiles += 10 * BITS.bitCount(wOpen & 0x18);
}
ulong bOpen = BitBoard.southFill(shelter) & (~BitBoard.southFill(bPawns)) & 0xff;
if (bOpen != 0) {
halfOpenFiles += 25 * BITS.bitCount(bOpen & 0xe7);
halfOpenFiles += 10 * BITS.bitCount(bOpen & 0x18);
}
safety = Math.Min(safety, 8);
}
int kSafety = (safety - 9) * 15 - halfOpenFiles;
score -= kSafety;
}
ksh.key = key;
ksh.score = score;
}
return ksh.score;
}