public void Recycle()
{
pos = null;
H = null;
mpExternal = null;
}
internal void MovePickerC(Position p, Move ttm, History h, PieceType pt)
{
pos = p;
H = h;
curMovePos = 0;
lastMovePos = 0;
Debug.Assert(!pos.in_check());
depth = 0;
ttMove = 0;
lastQuietPos = 0; lastBadCapturePos = 0;
mpos = 0;
phase = SequencerC.PROBCUT;
// In ProbCut we generate only captures better than parent's captured piece
captureThreshold = Position.PieceValueMidgame[pt];
ttMove = ((ttm != 0) && pos.is_pseudo_legal(ttm) ? ttm : MoveC.MOVE_NONE);
if ((ttMove != 0) && (!pos.is_capture(ttMove) || pos.see(ttMove, false) <= captureThreshold))
ttMove = MoveC.MOVE_NONE;
lastMovePos += ((ttMove != MoveC.MOVE_NONE) ? 1 : 0);
}
internal void MovePickerC(Position p, Move ttm, Depth d, History h,
Square sq)
{
pos = p;
H = h;
curMovePos = 0;
lastMovePos = 0;
Debug.Assert(d <= DepthC.DEPTH_ZERO);
depth = 0;
recaptureSquare = 0;
captureThreshold = 0;
lastQuietPos = 0; lastBadCapturePos = 0;
mpos = 0;
if (p.in_check())
phase = SequencerC.EVASION;
else if (d > DepthC.DEPTH_QS_NO_CHECKS)
phase = SequencerC.QSEARCH_0;
else if (d > DepthC.DEPTH_QS_RECAPTURES)
{
phase = SequencerC.QSEARCH_1;
// Skip TT move if is not a capture or a promotion, this avoids qsearch
// tree explosion due to a possible perpetual check or similar rare cases
// when TT table is full.
if ((ttm != 0) && !pos.is_capture_or_promotion(ttm))
ttm = MoveC.MOVE_NONE;
}
else
{
phase = SequencerC.RECAPTURE;
recaptureSquare = sq;
ttm = MoveC.MOVE_NONE;
}
ttMove = ((ttm != 0) && pos.is_pseudo_legal(ttm) ? ttm : MoveC.MOVE_NONE);
lastMovePos += ((ttMove != MoveC.MOVE_NONE) ? 1 : 0);
}
/// Constructors of the MovePicker class. As arguments we pass information
/// to help it to return the presumably good moves first, to decide which
/// moves to return (in the quiescence search, for instance, we only want to
/// search captures, promotions and some checks) and about how important good
/// move ordering is at the current node.
internal void MovePickerC(Position p, Move ttm, Depth d, History h,
Stack ss, Value beta, MovePicker mpExt)
{
pos = p;
H = h;
depth = d;
mpExternal = mpExt;
Debug.Assert(d > DepthC.DEPTH_ZERO);
captureThreshold = 0;
curMovePos = lastMovePos = 0;
lastBadCapturePos = Constants.MAX_MOVES - 1;
recaptureSquare = 0;
lastQuietPos = 0;
mpos = 0;
if (p.in_check())
{
phase = SequencerC.EVASION;
}
else
{
phase = SequencerC.MAIN_SEARCH;
ms[Constants.MAX_MOVES].move = ss.killers0;
ms[Constants.MAX_MOVES + 1].move = ss.killers1;
// Consider sligtly negative captures as good if at low depth and far from beta
if (ss.eval < beta - Constants.PawnValueMidgame && d < 3 * DepthC.ONE_PLY)
captureThreshold = -Constants.PawnValueMidgame;
// Consider negative captures as good if still enough to reach beta
else if (ss.eval > beta)
captureThreshold = beta - ss.eval;
}
ttMove = (ttm != 0 && pos.is_pseudo_legal(ttm) ? ttm : MoveC.MOVE_NONE);
lastMovePos += ((ttMove != MoveC.MOVE_NONE) ? 1 : 0);
}
public void Recycle()
{
this.pos = null;
this.H = null;
this.mpExternal = null;
}
internal void MovePickerC(Position p, int ttm, History h, int pt)
{
this.pos = p;
this.H = h;
this.curMovePos = 0;
this.lastMovePos = 0;
Debug.Assert(!this.pos.in_check());
this.depth = 0;
this.ttMove = 0;
this.lastQuietPos = 0;
this.lastBadCapturePos = 0;
this.mpos = 0;
this.phase = SequencerC.PROBCUT;
// In ProbCut we generate only captures better than parentSplitPoint's captured piece
this.captureThreshold = Position.PieceValue[PhaseC.MG][pt];
this.ttMove = ((ttm != 0) && this.pos.is_pseudo_legal(ttm) ? ttm : MoveC.MOVE_NONE);
if ((this.ttMove != 0)
&& (!this.pos.is_capture(this.ttMove) || this.pos.see(this.ttMove, false) <= this.captureThreshold))
{
this.ttMove = MoveC.MOVE_NONE;
}
this.lastMovePos += ((this.ttMove != MoveC.MOVE_NONE) ? 1 : 0);
}