void cEval::ScoreKing(POS *p, int sd) {
const int startSq[2] = { E1, E8 };
const int qCastle[2] = { B1, B8 };
const int kCastle[2] = { G1, G8 };
U64 bbKingFile, bbNextFile;
int result = 0;
int sq = KingSq(p, sd);
// Normalize king square for pawn shield evaluation,
// to discourage shuffling the king between g1 and h1.
if (SqBb(sq) & bbKSCastle[sd]) sq = kCastle[sd];
if (SqBb(sq) & bbQSCastle[sd]) sq = qCastle[sd];
// Evaluate shielding and storming pawns on each file.
bbKingFile = BB.FillNorthSq(sq) | BB.FillSouthSq(sq);
result += ScoreKingFile(p, sd, bbKingFile);
bbNextFile = ShiftEast(bbKingFile);
if (bbNextFile) result += ScoreKingFile(p, sd, bbNextFile);
bbNextFile = ShiftWest(bbKingFile);
if (bbNextFile) result += ScoreKingFile(p, sd, bbNextFile);
mg[sd][F_PAWNS] += result;
mg[sd][F_PAWNS] += ScoreChains(p, sd);
}
void sEvaluator::SinglePawnScore(sPosition *p, int side)
{
int sq, flagIsOpen, flagIsWeak;
int oppo = Opp(side);
U64 flagIsPhalanx, flagPhalanx2, flagIsDoubled, bbFrontSpan;
U64 bbPieces = bbPc(p, side, P);
U64 bbOwnPawns = bbPieces;
while (bbPieces) {
sq = PopFirstBit(&bbPieces);
// gather information about a pawn that is evaluated
bbFrontSpan = GetFrontSpan(SqBb(sq), side );
flagIsDoubled = bbFrontSpan & bbOwnPawns;
flagIsOpen = !( bbFrontSpan & bbPc(p, oppo, P) );
flagIsPhalanx = ShiftEast(SqBb(sq) ) & bbOwnPawns;
flagPhalanx2 = ShiftWest(SqBb(sq) ) & bbOwnPawns;
flagIsWeak = !( bbPawnSupport[side][sq] & bbOwnPawns );
if (flagIsDoubled) {
pawnScoreMg[side] += doubledPawn[MG][File(sq)];
pawnScoreEg[side] += doubledPawn[EG][File(sq)];
}
if (flagIsPhalanx) {
pawnScoreMg[side] += Data.pawnProperty[PHALANX][MG][side][sq];
//pawnScoreEg[side] += Data.phalanxEg[side][sq];
}
if (flagIsOpen) {
U64 bbObstacles = bbPassedMask[side][sq] & bbPc(p, oppo, P);
// passed pawn (some more eval will be done in ScoreP() in eval_pieces.c)
if (!bbObstacles) {
if (flagIsDoubled) AddPasserScore(CANDIDATE,side,sq); // back doubled passer is scored like candidate,
else AddPasserScore(PASSED,side,sq); // only frontmost passer gets full credit
}
// candidate passer
if (flagIsPhalanx || flagPhalanx2) { // test lower bonus when !flagIsWeak
if (PopCntSparse(bbObstacles) == 1) AddPasserScore(CANDIDATE,side,sq);
}
}
if (flagIsWeak) {
if (!(bbAdjacentMask[File(sq)] & bbOwnPawns)) { // isolated
AddPawnProperty(ISOLATED,side,sq);
if (flagIsOpen) pawnScoreMg[side] += pawnIsolatedOnOpen;
} else { // backward
AddPawnProperty(BACKWARD,side,sq);
if (flagIsOpen) pawnScoreMg[side] += pawnBackwardOnOpen;
}
}
}
}
