void State::makeMove(Move const & move) {
FromTo const & fromTo = move.fromTo;
movePiece(fromTo, &board);
if (move.castle.from.file) {
movePiece(move.castle, &board);
}
if (move.enPassCap.file) {
getPieceRef(move.enPassCap, &board) = ' ';
}
if (move.promPiece) {
getPieceRef(fromTo.to, &board) = makePiece(move.promPiece, turn);
}
turn = (State::WHITE == turn) ? State::BLACK : State::WHITE;
}
//quiescence search
int SimplePVSearch::qSearch(Board& board, SearchInfo& si) {
if (stop(si)) {
return 0;
}
if (board.isDraw() || si.ply >= maxSearchPly-1) {
return drawScore;
}
TranspositionTable::HashData hashData;
MoveIterator::Move hashMove;
const Key key = board.getKey();
bool okToPrune=false;
const int oldAlpha=si.alpha;
// tt retrieve & prunning
const bool hashOk = si.nodeType == PV_NODE ?
agent->hashGet(okToPrune, key, hashData,
si.ply, si.depth) :
agent->hashGet(okToPrune, key, hashData,
si.ply, si.depth, si.allowNullMove, si.alpha, si.beta);
if (hashOk) {
hashMove = hashData.move();
if (okToPrune) {
return hashData.value();
}
}
const bool isKingAttacked = board.isInCheck();
bool isLazyEval = false;
int bestScore = -maxScore;
int currentScore = -maxScore;
if (!isKingAttacked) {
if (hashOk && (hashData.flag() & TranspositionTable::NODE_EVAL)) {
currentScore = hashData.evalValue();
} else {
currentScore=evaluator.evaluate(board,si.alpha,si.beta);
isLazyEval = evaluator.isLazyEval();
}
bestScore=currentScore;
if(bestScore>=si.beta) {
if (!hashOk && !isLazyEval) {
const TranspositionTable::NodeFlag flag = TranspositionTable::NODE_EVAL;
agent->hashPut(key,bestScore,currentScore,-maxSearchPly,si.ply,flag,emptyMove);
}
return bestScore;
}
const int delta = board.isPawnPromoting()?getDeltaMargin(si.depth)*2:getDeltaMargin(si.depth);
if (bestScore < si.alpha - delta && !(si.nodeType==PV_NODE) && hashMove.none() &&
!isMateScore(si.beta)) {
if (!hashOk && !isLazyEval) {
const TranspositionTable::NodeFlag flag = TranspositionTable::NODE_EVAL;
agent->hashPut(key,si.alpha,currentScore,-maxSearchPly,si.ply,flag,emptyMove);
}
return si.alpha;
}
if((si.nodeType==PV_NODE) && si.alpha<bestScore) {
si.alpha = bestScore;
}
}
int moveCounter=0;
MoveIterator moves = MoveIterator();
MoveIterator::Move bestMove=emptyMove;
MoveIterator::Move move;
const PieceColor sideToMove = board.getSideToMove();
while (true) {
move = selectMove<true>(board, moves, hashMove, si.ply, si.depth);
if (move.none()) {
break;
}
const bool isHashMove = move.type==MoveIterator::TT_MOVE;
const bool passedPawn = isPawnPush(board,move.to);
const bool pawnOn7thRank = move.promotionPiece!=EMPTY;
const bool allowFutility = !isKingAttacked && !(si.nodeType==PV_NODE) &&
!isHashMove && !pawnOn7thRank;
moveCounter++;
if (move.promotionPiece==makePiece(sideToMove,ROOK) ||
move.promotionPiece==makePiece(sideToMove,BISHOP) ) {
continue;
}
if (allowFutility) {
if (si.depth < qsOnlyRecaptureDepth && move.to != si.move.to) {
continue;
}
if (move.type==MoveIterator::BAD_CAPTURE) {
continue;
}
}
MoveBackup backup;
board.doMove(move,backup);
const bool givingCheck = board.setInCheck(board.getSideToMove());
if (move.promotionPiece==makePiece(sideToMove,KNIGHT) &&
!givingCheck) {
board.undoMove(backup);
continue;
}
if (allowFutility && !board.isPawnFinal() && !passedPawn && !givingCheck ) {
const int gain = materialValues[backup.capturedPiece];
const int futilityScore = currentScore+gain+getFutilityMargin();
if (futilityScore<si.alpha) {
if (futilityScore>bestScore) {
bestScore=futilityScore;
}
board.undoMove(backup);
continue;
}
}
SearchInfo newSi(false,move,-si.beta,-si.alpha,si.depth-1,
si.ply+1,si.nodeType,si.splitPoint);
int score = -qSearch(board, newSi);
board.undoMove(backup);
if (stop(si)) {
return 0;
}
nodes++;
if( score >= si.beta ) {
const TranspositionTable::NodeFlag flag = currentScore!=-maxScore && !isLazyEval?
TranspositionTable::LOWER_EVAL:TranspositionTable::LOWER;
agent->hashPut(key,score,currentScore,si.depth!=0?-1:0,si.ply,flag,move);
return score;
}
if (score>bestScore) {
bestScore=score;
if( score>si.alpha ) {
si.alpha = score;
bestMove=move;
}
}
}
if (!moveCounter && isKingAttacked) {
return -maxScore+si.ply;
}
TranspositionTable::NodeFlag flag;
if (bestScore>oldAlpha) {
flag = currentScore!=-maxScore && !isLazyEval?
TranspositionTable::EXACT_EVAL:TranspositionTable::EXACT;
} else {
flag = currentScore!=-maxScore && !isLazyEval?
TranspositionTable::UPPER_EVAL:TranspositionTable::UPPER;
bestMove=emptyMove;
}
agent->hashPut(key,bestScore,currentScore,si.depth!=0?-1:0,si.ply,flag,bestMove);
return bestScore;
}