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Merge pull request 'Add SnappingNoder seeding' (!116) from mdavis/geos:add-snappingnoder-seeding into main
continuous-integration/drone/push Build is passing Details 

Reviewed-on: #116
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mdavis 2021-10-28 16:33:26 -07:00
parent befc941dc7 89397ea6a8
commit c693615c05
2 changed files with 36 additions and 3 deletions
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6
include/geos/noding/snap/SnappingNoder.h
View File

@ -73,6 +73,9 @@ private:
std::vector<SegmentString*>* nodedResult;
// Methods
void seedSnapIndex(std::vector<SegmentString*>& segStrings);
void snapVertices(std::vector<SegmentString*>& segStrings, std::vector<SegmentString*>& nodedStrings);
SegmentString* snapVertices(SegmentString* ss);
@ -115,6 +118,3 @@ public:
} // namespace geos::noding::snap
} // namespace geos::noding
} // namespace geos

33
src/noding/snap/SnappingNoder.cpp
View File

@ -24,6 +24,8 @@
#include <geos/noding/snap/SnappingNoder.h>
#include <geos/noding/snap/SnappingIntersectionAdder.h>
//#include <geos/profiler.h>
#include <algorithm> // for std::min and std::max
#include <memory>
@ -53,12 +55,43 @@ SnappingNoder::computeNodes(std::vector<SegmentString*>* inputSegStrings)
void
SnappingNoder::snapVertices(std::vector<SegmentString*>& segStrings, std::vector<SegmentString*>& nodedStrings)
{
//geos::util::Profiler* profiler = geos::util::Profiler::instance();
//auto sw = profiler->get(std::string("SnappingNoder::snapVertices"));
//sw->start();
seedSnapIndex(segStrings);
for (SegmentString* ss: segStrings) {
nodedStrings.push_back(snapVertices(ss));
}
//sw->stop();
//std::cout << sw->name << " - " << sw->getTotFormatted() << std::endl;
}
/*private*/
void
SnappingNoder::seedSnapIndex(std::vector<SegmentString*>& segStrings)
{
double PHI_INV = (sqrt(5) - 1.0) / 2.0;
for (SegmentString* ss: segStrings) {
CoordinateSequence* cs = ss->getCoordinates();
int numPts = (int) cs->size();
int numPtsToLoad = numPts / 100;
double rand = 0.0;
for (int i = 0; i < numPtsToLoad; i++) {
// quasi-random sequennce generated by additive recurrence with irrational constant
rand = rand + PHI_INV;
if (rand > 1) rand = rand - floor(rand);
int index = (int) (numPts * rand);
snapIndex.snap(cs->getAt(index));
}
}
}
/*private*/
SegmentString*
SnappingNoder::snapVertices(SegmentString* ss)