bool GoRegion::ProtectedCuts(const GoBoard& board) const
{
if (! GetFlag(GO_REGION_CORRIDOR))
return false;
if (m_blocks.IsLength(2))
/* */ return Safe2Cuts(board); /* */ // easy case of only 2 blocks
bool prot = true;
SgPointSet allCuts;
const int size = board.Size();
GoBlock* block1, *block2;
for (SgVectorPairIteratorOf<GoBlock> it(m_blocks);
it.NextPair(block1, block2);)
{
SgPointSet lib1(block1->Stones().Border(size));
SgPointSet lib2(block2->Stones().Border(size));
SgPointSet cuts(lib1 & lib2 & Points());
if (! cuts.SubsetOf(board.AllEmpty()))
// cut occupied by opponent. Bad for us.
return false;
else
allCuts |= cuts;
}
// no eye space left ? hard to distinguish false eyes from ok
// AR why must this be checked??? Should not matter for flat regions.
// Try to take it out.
//if (Points().SubsetOf(allCuts | allCuts.Border()))
// prot = false;
return prot;
}
SgPointSet SpUtil::GetRelevantMoves(GoBoard& bd, SgBlackWhite toPlay,
bool useFilter)
{
SgPointSet legal;
for (SgSetIterator it(bd.AllEmpty()); it; ++it)
if (bd.IsLegal(*it))
legal.Include(*it);
if (! useFilter)
return legal;
GoSafetySolver safetySolver(bd);
SgBWSet safe;
safetySolver.FindSafePoints(&safe);
SgBlackWhite opp = SgOppBW(toPlay);
SgPointSet moves;
const GoRules& rules = bd.Rules();
const bool captureDead = rules.CaptureDead();
//const bool japaneseScoring = rules.JapaneseScoring();
for (SgSetIterator it(legal); it; ++it)
{
SgPoint p = *it;
const bool isSafe = safe[toPlay].Contains(p);
const bool isSafeOpp = safe[opp].Contains(p);
const bool hasOppNeighbors = bd.HasNeighbors(p, opp);
if ( (! isSafe && ! isSafeOpp)
|| (isSafe && captureDead && hasOppNeighbors)
// || (isSafeOpp && ! japaneseScoring)
)
moves.Include(p);
}
return moves;
}
int LibertyAveragex10(const GoBoard& board, SgBlackWhite color)
{
int nuLibs = 0, nuBlocks = 0;
const int size = board.Size();
for (SgConnCompIterator it(board.All(color), board.Size()); it; ++it)
{
++nuBlocks;
nuLibs += ((*it).Border(size) & board.AllEmpty()).Size();
}
return (nuBlocks == 0) ? 0 : 10 * nuLibs / nuBlocks;
}
bool GoRegion::Safe2Cuts(const GoBoard& board) const
{
SG_ASSERT(m_blocks.IsLength(2));
const int size = board.Size();
GoBlock* block1 = m_blocks.Front();
GoBlock* block2 = m_blocks.Back();
SgPointSet cuts(Points());
cuts -= board.AllEmpty();
if (cuts.IsEmpty())
/* */ return true; /* */
cuts &= block1->Stones().Border(size);
cuts &= block2->Stones().Border(size);
return cuts.IsEmpty();
}
void GoEyeUtil::TestNakade(const SgPointSet& points,
const GoBoard& bd,
SgBlackWhite color,
bool isFullyEnclosed,
bool& isNakade,
bool& makeNakade,
bool& makeFalse,
bool& maybeSeki,
bool& sureSeki,
SgPoint* vital)
{ // handles case
// of more than 1 point passing vital point test.
// passes back vital point if exactly one is found.
// @todo handle case where vital is illegal or suicide (eye within eye?).
// also test bigger, would-be-alive shapes in atari.
// @todo handle seki.
SG_UNUSED(makeFalse);
isNakade = makeNakade = maybeSeki = sureSeki = false;
SgPoint vitalP(SG_NULLPOINT);
const SgBlackWhite opp = SgOppBW(color);
const int nuPoints = points.Size();
SG_ASSERT(nuPoints >= 3); // don't call for smaller areas, no need,
// and results in isNakade = false which is confusing.
if (nuPoints == 4) // special case 4 point areas
{
if (IsBulkyFour(points))
{
if ( isFullyEnclosed
&& TwoDiagonalStonesInBulkyFour(bd, points, opp)
)
makeNakade = true;
else
isNakade = true;
/* */ return; /* */
}
else if ( isFullyEnclosed
&& points.SubsetOf(bd.AllEmpty())
&& IsBentFour(points, bd.Size(), vital)
)
{
makeNakade = true;
/* */ return; /* */
}
}
else if (isFullyEnclosed && nuPoints == 5) // special case 5 point areas
{
const GoEyeStatus status = BulkyFiveNakade(bd, points, opp);
if (ProcessStatus(status, isNakade, makeNakade))
/* */ return; /* */
}
else if (isFullyEnclosed && nuPoints == 6) // special case 6 point areas
{
if (Is2x3Area (points))
{
GoEyeStatus status = Special2x3Cases(bd, points, opp);
if (ProcessStatus(status, isNakade, makeNakade))
/* */ return; /* */
}
}
if ( isFullyEnclosed
&& AlmostFilledByNakade(bd, points, opp)
)
{
isNakade = true;
/* */ return; /* */
}
if ( isFullyEnclosed
&& ( AlmostFilledByLivingShape(bd, points, opp)
|| ContainsLivingShape(bd, points, opp)
)
)
{ // not nakade, 2 eyes
/* */ return; /* */
}
int nuMakeNakade = 0;
int nuVitalOccupied = 0;
bool hasDivider = false;
// counting number of nakade fixes bug with stretched 5 pt eye
// that had 3 vital pts,
// one of them occupied. was classified as 'isNakade7 = 1 eye.
// see sgf/ld200,#20
for (SgSetIterator it(points); it; ++it)
{
SgPoint p(*it);
if (IsVitalPt(points, p, opp, bd))
{
if (bd.IsEmpty(p))
{
if (bd.IsLegal(p, opp))
{
++nuMakeNakade;
vitalP = p;
}
else
hasDivider = true;
}
else
++nuVitalOccupied;
}
}
if (hasDivider)
{ // alive
}
else if (nuMakeNakade == 1) // exactly one way to make nakade here.
{
makeNakade = true;
*vital = vitalP;
}
else if (nuMakeNakade > 0)
isNakade = false;
else if (nuVitalOccupied < 3)
isNakade = true;
else
{
maybeSeki = true;
// @todo if (IsSureSekiShape(...)) sureSeki = true;
}
}
