bool AreaAreaIndex::GetOffsets(const TypeConfigRef& typeConfig,
double minlon,
double minlat,
double maxlon,
double maxlat,
size_t maxLevel,
const TypeSet& types,
size_t maxCount,
std::vector<FileOffset>& offsets) const
{
std::vector<CellRef> cellRefs; // cells to scan in this level
std::vector<CellRef> nextCellRefs; // cells to scan for the next level
std::vector<FileOffset> newOffsets; // offsets collected in the current level
minlon+=180;
maxlon+=180;
minlat+=90;
maxlat+=90;
// Clear result datastructures
offsets.clear();
// Make the vector preallocate memory for the expected data size
// This should void reallocation
offsets.reserve(std::min(100000u,(uint32_t)maxCount));
newOffsets.reserve(std::min(100000u,(uint32_t)maxCount));
cellRefs.reserve(1000);
nextCellRefs.reserve(1000);
cellRefs.push_back(CellRef(topLevelOffset,0,0));
// For all levels:
// * Take the tiles and offsets of the last level
// * Calculate the new tiles and offsets that still interfere with given area
// * Add the new offsets to the list of offsets and finish if we have
// reached maxLevel or maxAreaCount.
// * copy no, ntx, nty to ctx, cty, co and go to next iteration
bool stopArea=false;
for (uint32_t level=0;
!stopArea &&
level<=this->maxLevel &&
level<=maxLevel &&
!cellRefs.empty();
level++) {
nextCellRefs.clear();
newOffsets.clear();
for (size_t i=0; !stopArea && i<cellRefs.size(); i++) {
size_t cx;
size_t cy;
IndexCache::CacheRef cell;
if (!GetIndexCell(*typeConfig,
level,
cellRefs[i].offset,
cell)) {
log.Error() << "Cannot find offset " << cellRefs[i].offset << " in level " << level << " in file '" << scanner.GetFilename() << "'";
return false;
}
if (offsets.size()+
newOffsets.size()+
cell->value.areas.size()>=maxCount) {
stopArea=true;
continue;
}
for (const auto entry : cell->value.areas) {
if (types.IsTypeSet(entry.type)) {
newOffsets.push_back(entry.offset);
}
}
cx=cellRefs[i].x*2;
cy=cellRefs[i].y*2;
if (cell->value.children[0]!=0) {
// top left
double x=cx*cellWidth[level+1];
double y=(cy+1)*cellHeight[level+1];
if (!(x>maxlon+cellWidth[level+1]/2 ||
y>maxlat+cellHeight[level+1]/2 ||
x+cellWidth[level+1]<minlon-cellWidth[level+1]/2 ||
y+cellHeight[level+1]<minlat-cellHeight[level+1]/2)) {
nextCellRefs.push_back(CellRef(cell->value.children[0],cx,cy+1));
}
}
if (cell->value.children[1]!=0) {
// top right
double x=(cx+1)*cellWidth[level+1];
double y=(cy+1)*cellHeight[level+1];
if (!(x>maxlon+cellWidth[level+1]/2 ||
y>maxlat+cellHeight[level+1]/2 ||
x+cellWidth[level+1]<minlon-cellWidth[level+1]/2 ||
y+cellHeight[level+1]<minlat-cellHeight[level+1]/2)) {
nextCellRefs.push_back(CellRef(cell->value.children[1],cx+1,cy+1));
}
}
if (cell->value.children[2]!=0) {
// bottom left
double x=cx*cellWidth[level+1];
double y=cy*cellHeight[level+1];
if (!(x>maxlon+cellWidth[level+1]/2 ||
y>maxlat+cellHeight[level+1]/2 ||
x+cellWidth[level+1]<minlon-cellWidth[level+1]/2 ||
y+cellHeight[level+1]<minlat-cellHeight[level+1]/2)) {
nextCellRefs.push_back(CellRef(cell->value.children[2],cx,cy));
}
}
if (cell->value.children[3]!=0) {
// bottom right
double x=(cx+1)*cellWidth[level+1];
double y=cy*cellHeight[level+1];
if (!(x>maxlon+cellWidth[level+1]/2 ||
y>maxlat+cellHeight[level+1]/2 ||
x+cellWidth[level+1]<minlon-cellWidth[level+1]/2 ||
y+cellHeight[level+1]<minlat-cellHeight[level+1]/2)) {
nextCellRefs.push_back(CellRef(cell->value.children[3],cx+1,cy));
}
}
}
if (!stopArea) {
offsets.insert(offsets.end(),newOffsets.begin(),newOffsets.end());
}
std::swap(cellRefs,nextCellRefs);
}
return true;
}
