/* static */
bool
LineSequencer::isSequenced(const Geometry* geom)
{
const MultiLineString *mls;
if ( nullptr == (mls=dynamic_cast<const MultiLineString *>(geom)) )
{
return true;
}
// the nodes in all subgraphs which have been completely scanned
Coordinate::ConstSet prevSubgraphNodes;
Coordinate::ConstVect currNodes;
const Coordinate* lastNode = nullptr;
for (std::size_t i=0, n=mls->getNumGeometries(); i<n; ++i)
{
const LineString* lineptr = \
dynamic_cast<const LineString*>(mls->getGeometryN(i));
assert(lineptr);
const LineString& line = *lineptr;
const Coordinate* startNode = &(line.getCoordinateN(0));
const Coordinate* endNode = &(line.getCoordinateN(line.getNumPoints() - 1));
/**
* If this linestring is connected to a previous subgraph,
* geom is not sequenced
*/
if (prevSubgraphNodes.find(startNode) != prevSubgraphNodes.end())
{
return false;
}
if (prevSubgraphNodes.find(endNode) != prevSubgraphNodes.end())
{
return false;
}
if (lastNode != nullptr)
{
if (! startNode->equals2D(*lastNode))
{
// start new connected sequence
prevSubgraphNodes.insert(currNodes.begin(),
currNodes.end());
currNodes.clear();
}
}
currNodes.push_back(startNode);
currNodes.push_back(endNode);
lastNode = endNode;
}
return true;
}
/* private */
void
ConvexHull::reduce(Coordinate::ConstVect &pts)
{
Coordinate::ConstVect polyPts;
if ( ! computeOctRing(pts, polyPts) ) {
// unable to compute interior polygon for some reason
return;
}
// add points defining polygon
Coordinate::ConstSet reducedSet;
reducedSet.insert(polyPts.begin(), polyPts.end());
/**
* Add all unique points not in the interior poly.
* CGAlgorithms.isPointInRing is not defined for points
* actually on the ring, but this doesn't matter since
* the points of the interior polygon are forced to be
* in the reduced set.
*
* @@TIP: there should be a std::algo for this
*/
for (size_t i=0, n=pts.size(); i<n; ++i)
{
if ( !CGAlgorithms::isPointInRing(*(pts[i]), polyPts) )
{
reducedSet.insert(pts[i]);
}
}
inputPts.assign(reducedSet.begin(), reducedSet.end());
if ( inputPts.size() < 3 ) padArray3(inputPts);
}