void ElementGeometryClipper::visitWay(const Way& way)
{
ClipperLib::Path wayShape;
PointLocation pointLocation = setPath(quadKeyBbox_, way, wayShape);
// 1. all geometry inside current quadkey: no need to truncate.
if (pointLocation == PointLocation::AllInside) {
callback_(way, quadKey_);
return;
}
// 2. all geometry outside : way should be skipped
if (pointLocation == PointLocation::AllOutside) {
return;
}
ClipperLib::PolyTree solution;
clipper_.AddPath(wayShape, ClipperLib::ptSubject, false);
clipper_.AddPath(createPathFromBoundingBox(), ClipperLib::ptClip, true);
clipper_.Execute(ClipperLib::ctIntersection, solution);
clipper_.Clear();
std::size_t count = static_cast<std::size_t>(solution.Total());
// 3. way intersects border only once: store a copy with clipped geometry
if (count == 1) {
Way clippedWay;
setData(clippedWay, way, solution.GetFirst()->Contour);
callback_(clippedWay, quadKey_);
}
// 4. in this case, result should be stored as relation (collection of ways)
else {
Relation relation;
relation.id = way.id;
relation.tags = way.tags;
relation.elements.reserve(count);
ClipperLib::PolyNode* polyNode = solution.GetFirst();
while (polyNode) {
auto clippedWay = std::make_shared<Way>();
clippedWay->id = way.id;
setCoordinates(*clippedWay, polyNode->Contour);
relation.elements.push_back(clippedWay);
polyNode = polyNode->GetNext();
}
callback_(relation, quadKey_);
}
}
void ElementGeometryClipper::visitRelation(const Relation& relation)
{
struct RelationVisitor : public ElementVisitor
{
RelationVisitor(const BoundingBox& quadKeyBbox, ClipperLib::Clipper& clipper) :
bbox_(quadKeyBbox), clipper_(clipper) { }
void visitNode(const Node& node)
{
// TODO
}
void visitWay(const Way& way)
{
ClipperLib::Path wayShape;
setPath(bbox_, way, wayShape);
clipper_.AddPath(wayShape, ClipperLib::ptSubject, false);
}
void visitArea(const Area& area)
{
ClipperLib::Path areaShape;
setPath(bbox_, area, areaShape);
clipper_.AddPath(areaShape, ClipperLib::ptSubject, true);
}
void visitRelation(const Relation& relation)
{
for (const auto& element : relation.elements) {
element->accept(*this);
}
}
private:
const BoundingBox& bbox_;
ClipperLib::Clipper& clipper_;
} visitor(quadKeyBbox_, clipper_);
relation.accept(visitor);
// Process results
ClipperLib::PolyTree solution;
clipper_.AddPath(createPathFromBoundingBox(), ClipperLib::ptClip, true);
clipper_.Execute(ClipperLib::ctIntersection, solution);
clipper_.Clear();
std::size_t count = static_cast<size_t>(solution.Total());
// Do not store one result as relation
if (count == 1) {
ClipperLib::PolyNode* node = solution.GetFirst();
if (node->IsOpen()) {
Way way;
setData(way, relation, node->Contour);
callback_(way, quadKey_);
}
else {
if (!node->IsHole()) {
Area area;
setData(area, relation, node->Contour);
callback_(area, quadKey_);
}
}
}
else if (count > 1) {
Relation newRelation;
newRelation.id = relation.id;
newRelation.tags = relation.tags;
newRelation.elements.reserve(count);
ClipperLib::PolyNode* polyNode = solution.GetFirst();
while (polyNode) {
if (polyNode->IsOpen()) {
auto way = std::make_shared<Way>();
setCoordinates(*way, polyNode->Contour);
newRelation.elements.push_back(way);
}
else {
auto area = std::make_shared<Area>();
setCoordinates(*area, polyNode->Contour);
newRelation.elements.push_back(area);
}
polyNode = polyNode->GetNext();
}
callback_(newRelation, quadKey_);
}
}