initial commit

src/pfaedle/osm/BBoxIdx.cpp

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+// Copyright 2018, University of Freiburg,
+// Chair of Algorithms and Data Structures.
+// Authors: Patrick Brosi <brosi@informatik.uni-freiburg.de>
+
+#include "pfaedle/osm/BBoxIdx.h"
+
+using pfaedle::osm::BBoxIdx;
+
+// _____________________________________________________________________________
+BBoxIdx::BBoxIdx(float padding) : _padding(padding), _size(0) {}
+
+// _____________________________________________________________________________
+void BBoxIdx::add(Box<float> box) {
+  // division by 83.000m is only correct here around a latitude deg of 25,
+  // but should be a good heuristic. 1 deg is around 63km at latitude deg of 44,
+  // and 110 at deg=0, since we usually dont do map matching in the arctic,
+  // its okay to use 83km here.
+  box = util::geo::pad(box, _padding / 83000);
+  addToTree(box, &_root, 0);
+  _size++;
+}
+
+// _____________________________________________________________________________
+size_t BBoxIdx::size() const { return _size; }
+
+// _____________________________________________________________________________
+bool BBoxIdx::contains(const Point<float>& p) const {
+  return treeHas(p, _root);
+}
+
+// _____________________________________________________________________________
+util::geo::Box<float> BBoxIdx::getFullWebMercBox() const {
+  return util::geo::FBox(
+      util::geo::latLngToWebMerc<float>(_root.box.min_corner().get<1>(),
+                                        _root.box.min_corner().get<0>()),
+      util::geo::latLngToWebMerc<float>(_root.box.max_corner().get<1>(),
+                                        _root.box.max_corner().get<0>()));
+}
+
+// _____________________________________________________________________________
+bool BBoxIdx::treeHas(const Point<float>& p, const BBoxIdxNd& nd) const {
+  if (!nd.childs.size()) return util::geo::contains(p, nd.box);
+  for (const auto& child : nd.childs) {
+    if (util::geo::contains(p, child.box)) return treeHas(p, child);
+  }
+
+  return false;
+}
+
+// _____________________________________________________________________________
+void BBoxIdx::addToTree(const Box<float>& box, BBoxIdxNd* nd, size_t lvl) {
+  double bestCommonArea = 0;
+  ssize_t bestChild = -1;
+
+  // 1. update the bbox of this node
+  nd->box = util::geo::extendBox(box, nd->box);
+
+  if (lvl == MAX_LVL) return;
+
+  // 2. find best candidate
+  for (size_t i = 0; i < nd->childs.size(); i++) {
+    double cur = util::geo::commonArea(box, nd->childs[i].box);
+    if (cur > MIN_COM_AREA && cur > bestCommonArea) {
+      bestChild = i;
+      bestCommonArea = cur;
+    }
+  }
+
+  if (bestChild < 0) {
+    // 3. add a new node with the inserted bbox
+    nd->childs.push_back(BBoxIdxNd(box));
+    addToTree(box, &nd->childs.back(), lvl + 1);
+  } else {
+    // 3. add to best node
+    addToTree(box, &nd->childs[bestChild], lvl + 1);
+  }
+
+  // TODO(patrick): some tree balancing by mergin overlapping bboxes in
+  // non-leafs
+}