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Fix findNearest termination - ensure we expand all octree nodes that might contain closer results than the current list.

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James Turner 2009-12-17 18:19:14 +00:00 • committed by Tim Moore
parent 34bbc6d974
commit 0637cba24a
1 changed files with 23 additions and 9 deletions
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32
src/Navaids/positioned.cxx
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@ -210,7 +210,9 @@ public:
FGPositioned::Filter* aFilter,
FindNearestResults& aResults, FindNearestPQueue&)
{
std::vector<Ordered<FGPositioned*> > results;
int previousResultsSize = aResults.size();
int addedCount = 0;
for (unsigned int i=0; i<_members.size(); ++i) {
FGPositioned* p = _members[i];
double d2 = distSqr(aPos, p->cart());
@ -228,8 +230,21 @@ public:
}
} // of have a filter
++addedCount;
aResults.push_back(OrderedPositioned(p, d2));
}
if (addedCount == 0) {
return;
}
// keep aResults sorted
// sort the new items, usually just one or two items
std::sort(aResults.begin() + previousResultsSize, aResults.end());
// merge the two sorted ranges together - in linear time
std::inplace_merge(aResults.begin(),
aResults.begin() + previousResultsSize, aResults.end());
}
private:
FGPositioned::List _members;
@ -321,10 +336,15 @@ void findNearestN(const SGVec3d& aPos, unsigned int aN, double aCutoffM, FGPosit
pq.push(Ordered<Node*>(global_spatialOctree, 0));
double cut = aCutoffM * aCutoffM;
while (aResults.size() < aN) {
if (pq.empty()) {
while (!pq.empty()) {
if (!results.empty()) {
// terminate the search if we have sufficent results, and we are
// sure no node still on the queue contains a closer match
double furthestResultOrder = results.back().order();
if ((results.size() >= aN) && (furthestResultOrder < pq.top().order())) {
break;
}
}
Node* nd = pq.top().get();
pq.pop();
@ -332,12 +352,9 @@ void findNearestN(const SGVec3d& aPos, unsigned int aN, double aCutoffM, FGPosit
nd->visit(aPos, cut, aFilter, results, pq);
} // of queue iteration
// sort by distance
std::sort(results.begin(), results.end());
// depending on leaf population, we may have (slighty) more results
// than requested
unsigned int numResults = std::min((unsigned int) results.size(), aN);
// copy results out
aResults.resize(numResults);
for (unsigned int r=0; r<numResults; ++r) {
@ -360,10 +377,7 @@ void findAllWithinRange(const SGVec3d& aPos, double aRangeM, FGPositioned::Filte
nd->visit(aPos, rng, aFilter, results, pq);
} // of queue iteration
// sort by distance
std::sort(results.begin(), results.end());
unsigned int numResults = results.size();
// copy results out
aResults.resize(numResults);
for (unsigned int r=0; r<numResults; ++r) {