public void RecordHash(ZobristHash hash, QuiescentFlag flag, int score)
{
if (!m_closed)
{
int i = CalculateHashIndex(hash);
m_hashTable[i].Hash.Key = hash.Key;
m_hashTable[i].Hash.Lock = hash.Lock;
m_hashTable[i].Flag = flag;
m_hashTable[i].Score = score;
}
}
public void RecordHash(ZobristHash hash, QuiescentFlag flag, int score)
{
if (!m_closed)
{
int i = CalculateHashIndex(hash);
m_hashTable[i].Hash.Key = hash.Key;
m_hashTable[i].Hash.Lock = hash.Lock;
m_hashTable[i].Flag = flag;
m_hashTable[i].Score = score;
}
}
/// <summary>
/// Carries out a narrow Quiescent search where only capure moves are searched.
/// </summary>
/// <param name="alpha">Current alpha value.</param>
/// <param name="beta">Current beta value.</param>
/// <returns>The score of a board.</returns>
private int QuiescentSearch(int alpha, int beta)
{
if (m_searchRollback)
{
return(beta);
}
//At interval check if time is up and rollback if so.
if (m_nodesVisited == m_nextRollbackCheck)
{
if (AbortingSearch())
{
m_alphaBetaTable.Close();
m_quiescentTable.Close();
m_searchRollback = true;
return(beta);
}
m_nextRollbackCheck += ROLLBACK_INTERVAL_COUNT;
}
++m_nodesVisited;
int score = 0;
QuiescentFlag quiescentFlag = QuiescentFlag.AlphaScore;
if (m_quiescentTable.ProbeScore(m_board.BoardHash(false), alpha, beta, ref score))
{
return(score);
}
score = m_evaluator.EvaluatePosition(m_board);
if (score >= beta)
{
m_quiescentTable.RecordHash(m_board.BoardHash(false), QuiescentFlag.BetaScore, beta);
return(beta);
}
if (score > alpha)
{
alpha = score;
quiescentFlag = QuiescentFlag.ExactScore;
}
MoveOrganizer currentMoves = new MoveOrganizer();
m_board.GeneratePseudoLegalMoves(currentMoves);
currentMoves.Sort(m_captureMoveCompare);
foreach (Move move in currentMoves)
{
if (!move.IsCaptureMove)
{
break;
}
if (move.Execute(m_board))
{
score = -QuiescentSearch(-beta, -alpha);
move.UnExecute(m_board);
if (score >= beta)
{
m_quiescentTable.RecordHash(m_board.BoardHash(false), QuiescentFlag.BetaScore, beta);
return(beta);
}
if (score > alpha)
{
alpha = score;
quiescentFlag = QuiescentFlag.ExactScore;
}
}
}
m_quiescentTable.RecordHash(m_board.BoardHash(false), quiescentFlag, alpha);
return(alpha);
}
