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Indoor/grid/walk/v3/GridWalk3Helper.h
frank 3807c621c7 added new helper methods
worked on gridWalker v3
2017-10-17 13:01:26 +02:00

114 lines
2.8 KiB
C++

#ifndef GRIDWALK3HELPER_H
#define GRIDWALK3HELPER_H
#include "../../../nav/dijkstra/Dijkstra.h"
#include <set>
template <typename Node> class GridWalk3Helper {
public:
/** one walk along several nodes */
struct Walk3 : public std::vector<const Node*> {
};
struct Walks3 : std::vector<Walk3> {
};
struct Nodes3 : std::vector<const Node*> {
};
/** get all possible walks from start within a given region */
static Walks3 getAllPossibleWalks(Grid<Node>& grid, const Node* start, const float dist_m) {
struct Access {
Grid<Node>& grid;
Access(Grid<Node>& grid) : grid(grid) {;}
int getNumNeighbors(const Node& n) const {return n.getNumNeighbors();}
Node* getNeighbor(const Node& n, const int idx) const {return &grid.getNeighbor(n, idx);}
float getWeightBetween(const Node& n1, const Node& n2) const {return n1.inMeter().getDistance(n2.inMeter());}
} acc(grid);
const float addDist_m = grid.getGridSize_cm() / 100.0f;
const float maxDist_m = dist_m * 1.1 + addDist_m;
Dijkstra<Node> dijkstra;
dijkstra.build(start, nullptr, acc, maxDist_m);
const std::unordered_map<const Node*, DijkstraNode<Node>*>& nodes = dijkstra.getNodes();
Walks3 walks;
for (const auto& it : nodes) {
Walk3 walk;
DijkstraNode<Node>* node = it.second;
do {
const Node* gridNode = node->element;
walk.insert(walk.begin(), gridNode); // push_front() as dijkstra is inverted
node = node->previous;
} while (node);
walks.push_back(walk);
}
return walks;
}
/** get all reachable nodes that are within a given range */
static Nodes3 getAllReachableNodes(Grid<Node>& grid, const Node* start, const float dist_m) {
Nodes3 res;
std::unordered_map<uint32_t, float> distances;
std::vector<uint32_t> toVisit;
toVisit.push_back(start->getIdx());
distances[start->getIdx()] = 0.0f;
while (!toVisit.empty()) {
int curIdx = toVisit.front();
toVisit.erase(toVisit.begin());
const Node& curNode = grid[curIdx];
const float curDistance = distances[curIdx];
res.push_back(&curNode); // remember for output
if (curDistance <= dist_m) {
for (int i = 0; i < curNode.getNumNeighbors(); ++i) {
const int neighborIdx = curNode.getNeighborIdx(i);
const Node& neighbor = grid[neighborIdx];
const float addDist = neighbor.inMeter().getDistance(curNode.inMeter());
const float totalDist = curDistance + addDist;
// this is like in dijkstra. keep the smallest distance to reach a node:
// not yet reached -> store distance
if (distances.find(neighborIdx) == distances.end()) {
toVisit.push_back(neighborIdx);
distances[neighborIdx] = totalDist;
// reached earlier but found shorter way
} else {
if (distances[neighborIdx] > totalDist) {
distances[neighborIdx] = totalDist;
}
}
}
}
}
return res;
}
};
#endif // GRIDWALK3HELPER_H