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Indoor/grid/walk/GridWalkHelper.h
FrankE e6329e1db4 dijkstra is now bleching fast
deleting from the grid is now bleaching fast
added new helper methods
many new test-cases
many new methods for geo classes and others
added a bunch of new grid-walkers
2016-01-26 18:13:30 +01:00

79 lines
2.4 KiB
C++

#ifndef GRIDWALKHELPER_H
#define GRIDWALKHELPER_H
#include "../../geo/Heading.h"
class GridWalkHelper {
public:
/** get the heading-change between the two given locations */
template <typename T> static Heading getHeading(const T& from, const T& to) {
return Heading(from.x_cm, from.y_cm, to.x_cm, to.y_cm);
}
/** get the neighbor of "from" best matching the given heading "h" */
template <typename T> static T& getBestNeighbor(Grid<T>& grid, const T& from, const Heading h) {
auto comp = [&] (const T& n1, const T& n2) {
const Heading h1 = getHeading(from, n1);
const Heading h2 = getHeading(from, n2);
const float d1 = h.getDiffHalfRAD(h1);
const float d2 = h.getDiffHalfRAD(h2);
//return (h.getDiffHalfRAD(h1) < h.getDiffHalfRAD(h2));
return (d1 == d2) ? (rand() < RAND_MAX/2) : (d1 < d2); // same heading? > random decision
};
auto neighbors = grid.neighbors(from);
return *std::min_element(neighbors.begin(), neighbors.end(), comp);
}
/**
* try to walk the given distance from the provided node.
* if this fails (algorithm cancel walk e.g. due to detected wall collissions)
* - try again from the start
* if this also fails several times
* - try to walk in the opposite direction instead (bounce-back)
* if this also fails
* - add some randomness and try again
*/
template <typename T, typename Walker> static GridWalkState<T> retryOrInvert(Walker& w, const int numRetries, Grid<T>& grid, GridWalkState<T> start, float distance_m) {
_assertTrue(distance_m >= 0, "distance must not be negative!");
GridWalkState<T> res;
//again:
int retries = numRetries;
// try to walk the given distance from the start
// if this fails (reached a dead end) -> restart (maybe the next try finds a better path)
do {
res = w.walk(grid, start, distance_m);
} while (res.node == nullptr && --retries);
// still reaching a dead end?
// -> try a walk in the opposite direction instead
if (res.node == nullptr) {
res = w.walk(grid, GridWalkState<T>(start.node, start.heading.getInverted()), distance_m);
}
// still nothing found? -> modify and try again
if (res.node == nullptr) {
// start.node = &(*grid.neighbors(*start.node).begin());
// start.heading += 0.25;
// goto again;
res.node = &(*grid.neighbors(*start.node).begin());
res.heading = start.heading;
}
return res;
}
};
#endif // GRIDWALKHELPER_H