Distribution combine(Distribution const& c, InfoMap const& info)
{
std::map<Cell, Value> tmp;
for (size_t i = 0; i < c.size(); ++i)
{
Distribution const& w = info(c.at(i).first)->weights;
Value const f = c.at(i).second;
for (size_t j = 0; j < w.size(); ++j)
{
Cell const v = w.at(j).first;
if (tmp.count(v) == 0)
tmp[v] = 0;
tmp[v] += f * w.at(j).second;
}
}
Distribution result(tmp.size());
std::map<Cell, Value>::const_iterator iter = tmp.begin();
for (size_t i = 0; i < tmp.size(); ++i, ++iter)
result[i] = std::make_pair(iter->first, iter->second);
return result;
}
Mask boundaries(
CubicalComplex const& complex,
Scalars const& scalars)
{
Facets I(complex.xdim(), complex.ydim(), complex.zdim(), false);
Facets coI(complex.xdim(), complex.ydim(), complex.zdim(), true);
VertexQueue queue;
InfoMap info(complex);
Mask result(complex);
for (Cell v = 0; v < complex.cellIdLimit(); ++v)
{
if (complex.isCell(v) and complex.cellDimension(v) == 0 and
isLocalMinimum(v, coI, I, scalars))
{
queue.push(v, scalars(v) + 1);
info.set(v, InfoPtr(new VertexInfo()));
result.set(v, 2);
}
}
while (not queue.empty())
{
Cell const v = queue.top();
queue.pop();
size_t const m = coI.count(v);
std::vector<size_t> lower;
for (size_t i = 0; i < m; ++i)
{
Cell const w = opposite(coI(v, i), v, I);
if (not info(w))
{
queue.push(w, scalars(w));
info.set(w, InfoPtr(new VertexInfo()));
}
else if (info(w)->active)
lower.push_back(w);
}
info(v)->active = true;
info(v)->countDown = m - lower.size();
if (lower.size() == 0)
{
info(v)->weights = Distribution(1);
info(v)->weights.at(0) = std::make_pair(v, 1);
info(v)->basin = v;
}
else
{
Distribution const dist =
derivedDistribution(v, lower, info, scalars);
info(v)->weights = dist;
std::set<size_t> seen;
for (size_t i = 0; i < lower.size(); ++i)
seen.insert(info(lower.at(i))->basin);
std::pair<size_t, Value> best;
size_t count = 0;
for (size_t i = 0; i < dist.size(); ++i)
if (seen.count(dist.at(i).first) > 0)
if (++count == 1 or dist.at(i).second > best.second)
best = dist.at(i);
info(v)->basin = best.first;
}
for (size_t i = 0; i < lower.size(); ++i)
{
Cell const w = lower.at(i);
if (info(v)->basin != info(w)->basin and scalars(v) <= 0)
result.set(std::min(v, w), 1);
if (--(info(w)->countDown) == 0)
info.set(w, InfoPtr());
}
}
return result;
}