bool GoEyeUtil::IsTreeShape(const SgPointSet& area)
{
for (SgSetIterator it(area); it; ++it)
{
const SgPoint p(*it);
if ( area.Contains(p + SG_NS)
&& area.Contains(p + SG_WE)
&& area.Contains(p + SG_NS + SG_WE)
)
return false;
}
return true;
}
long GoEyeUtil::DegreeCode8(const SgPointSet& points)
{
int degrees[9] = {0,0,0,0,0};
for (SgSetIterator it(points); it; ++it)
{
const SgPoint p(*it);
int nbs = 0;
for (SgNb8Iterator it(p); it; ++it)
{
if (points.Contains(*it))
++nbs;
}
++(degrees[nbs]);
}
return degrees[0]
+ 10 * degrees[1]
+ 100 * degrees[2]
+ 1000 * degrees[3]
+ 10000 * degrees[4]
+ 100000 * degrees[5]
+ 1000000 * degrees[6]
+ 10000000 * degrees[7]
+ 100000000 * degrees[8];
}
void GoChain::GetBlocks(const GoRegionBoard* ra,
SgVectorOf<GoBlock>* blocks) const
{
SgBlackWhite color = Color();
SgPointSet chainPts = Stones();
for (SgVectorIteratorOf<GoBlock> it(ra->AllBlocks(color)); it; ++it)
if (chainPts.Contains((*it)->Anchor()))
blocks->PushBack(*it);
}
bool GoEyeUtil::CheckInterior(const GoBoard& bd, const SgPointSet& area,
SgBlackWhite opp, bool checkBlocks)
{
bool hasSingleNbPoint = false;
int nuPoints = 0;
for (SgSetIterator it(area); it; ++it)
{
const SgPoint p(*it);
if (bd.IsEmpty(p))
{
int nuNbs = 0;
if (area.Contains(p + SG_NS))
++nuNbs;
if (area.Contains(p - SG_NS))
++nuNbs;
if (area.Contains(p + SG_WE))
++nuNbs;
if (area.Contains(p - SG_WE))
++nuNbs;
if (nuNbs == 1)
hasSingleNbPoint = true;
else if (nuNbs > 2)
return false;
}
else if (p == bd.Anchor(p))
{
if (bd.GetColor(p) != opp)
// if own stones on inside: not a tree shape.
return false;
int nuLibs = bd.NumLiberties(p);
if (nuLibs == 1)
hasSingleNbPoint = true;
else if (checkBlocks && nuLibs > 2)
return false;
}
++nuPoints;
}
return nuPoints == 1 || hasSingleNbPoint;
}
bool GoEyeUtil::IsLocalSplitPt(SgPoint p, const SgPointSet& set)
{
int nuNb = 0;
for (SgNb4Iterator it(p); it; ++it)
{
if (set.Contains(*it))
{
++nuNb;
if (nuNb >= 2)
break;
}
}
if (nuNb >= 2)
{
if (set[p - SG_NS])
{
if (set[p - SG_WE] && TestDiagonal(set, p, -SG_NS, -SG_WE))
return true;
if (set[p + SG_NS] && TestOpposite(set, p, SG_NS, SG_WE))
return true;
if (set[p + SG_WE] && TestDiagonal(set, p, -SG_NS, +SG_WE))
return true;
}
if (set[p + SG_NS])
{
if (set[p - SG_WE] && TestDiagonal(set, p, +SG_NS, -SG_WE))
return true;
if (set[p + SG_WE] && TestDiagonal(set, p, +SG_NS, +SG_WE))
return true;
}
if (set[p - SG_WE] && set[p + SG_WE]
&& TestOpposite(set, p, SG_WE, SG_NS))
return true;
}
return false; // no local split found.
}