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#include "routing.h"
#include "ortools/constraint_solver/routing.h"
#include "ortools/constraint_solver/routing_enums.pb.h"
#include "ortools/constraint_solver/routing_index_manager.h"
#include "ortools/constraint_solver/routing_parameters.h"
using namespace operations_research;
// Aux struct and functions.
struct InternalParameters {
InternalParameters()
: numSolutionsPerRun(1), numRuns(1), minNumTransectsPerRun(5),
stop([] { return false; }) {}
std::size_t numSolutionsPerRun;
std::size_t numRuns;
std::size_t minNumTransectsPerRun;
std::function<bool(void)> stop;
mutable std::string errorString;
};
bool getRoute(const FPolygon &area, const LineStringArray &transects,
std::vector<Solution> &solutionVector,
const InternalParameters &par = InternalParameters());
bool getRoute(const FPolygon &area, const LineStringArray &transects,
std::vector<Solution> &solutionVector,
const InternalParameters &par) {
#ifdef SNAKE_SHOW_TIME
auto start = std::chrono::high_resolution_clock::now();
#endif
//================================================================
// Create routing model.
//================================================================
// Use integer polygons to increase numerical robustness.
// Convert area;
IPolygon intArea;
for (const auto &v : area.outer()) {
auto p = float2Int(v);
intArea.outer().push_back(p);
}
for (const auto &ring : area.inners()) {
IRing intRing;
for (const auto &v : ring) {
auto p = float2Int(v);
intRing.push_back(p);
}
intArea.inners().push_back(std::move(intRing));
}
// Helper classes.
struct VirtualNode {
VirtualNode(std::size_t f, std::size_t t) : fromIndex(f), toIndex(t) {}
std::size_t fromIndex; // index for leaving node
std::size_t toIndex; // index for entering node
};
struct NodeToTransect {
NodeToTransect(std::size_t i, bool r) : transectsIndex(i), reversed(r) {}
std::size_t transectsIndex; // transects index
bool reversed; // transect reversed?
};
// Create vertex and node list
std::vector<IPoint> vertices;
std::vector<std::pair<std::size_t, std::size_t>> disjointNodes;
std::vector<VirtualNode> nodeList;
std::vector<NodeToTransect> nodeToTransectList;
for (std::size_t i = 0; i < transects.size(); ++i) {
const auto &t = transects[i];
// Copy line edges only.
if (t.size() == 1 || i == 0) {
auto p = float2Int(t.back());
vertices.push_back(p);
nodeToTransectList.emplace_back(i, false);
auto idx = vertices.size() - 1;
nodeList.emplace_back(idx, idx);
} else if (t.size() > 1) {
auto p1 = float2Int(t.front());
auto p2 = float2Int(t.back());
vertices.push_back(p1);
vertices.push_back(p2);
nodeToTransectList.emplace_back(i, false);
nodeToTransectList.emplace_back(i, true);
auto fromIdx = vertices.size() - 1;
auto toIdx = fromIdx - 1;
nodeList.emplace_back(fromIdx, toIdx);
nodeList.emplace_back(toIdx, fromIdx);
disjointNodes.emplace_back(toIdx, fromIdx);
} else { // transect empty
std::cout << "ignoring empty transect with index " << i << std::endl;
}
}
#ifdef SNAKE_DEBUG
// Print.
std::cout << "nodeToTransectList:" << std::endl;
std::cout << "node:transectIndex:reversed" << std::endl;
std::size_t c = 0;
for (const auto &n2t : nodeToTransectList) {
std::cout << c++ << ":" << n2t.transectsIndex << ":" << n2t.reversed
<< std::endl;
}
std::cout << "nodeList:" << std::endl;
std::cout << "node:fromIndex:toIndex" << std::endl;
c = 0;
for (const auto &n : nodeList) {
std::cout << c++ << ":" << n.fromIndex << ":" << n.toIndex << std::endl;
}
std::cout << "disjoint nodes:" << std::endl;
std::cout << "number:nodes" << std::endl;
c = 0;
for (const auto &d : disjointNodes) {
std::cout << c++ << ":" << d.first << "," << d.second << std::endl;
}
#endif
// Add polygon vertices.
for (auto &v : intArea.outer()) {
vertices.push_back(v);
}
for (auto &ring : intArea.inners()) {
for (auto &v : ring) {
vertices.push_back(v);
}
}
// Create connection graph (inf == no connection between vertices).
// Note: graph is not symmetric.
auto n = vertices.size();
// Matrix must be double since integers don't have infinity and nan
Matrix<double> connectionGraph(n, n);
for (std::size_t i = 0; i < n; ++i) {
auto &fromVertex = vertices[i];
for (std::size_t j = 0; j < n; ++j) {
auto &toVertex = vertices[j];
ILineString line{fromVertex, toVertex};
if (bg::covered_by(line, intArea)) {
connectionGraph(i, j) = bg::length(line);
} else {
connectionGraph(i, j) = std::numeric_limits<double>::infinity();
}
}
}
#ifdef SNAKE_DEBUG
std::cout << "connection grah:" << std::endl;
std::cout << connectionGraph << std::endl;
#endif
// Create distance matrix.
auto distLambda = [&connectionGraph](std::size_t i, std::size_t j) -> double {
return connectionGraph(i, j);
};
auto nNodes = nodeList.size();
Matrix<IntType> distanceMatrix(nNodes, nNodes);
for (std::size_t i = 0; i < nNodes; ++i) {
distanceMatrix(i, i) = 0;
for (std::size_t j = i + 1; j < nNodes; ++j) {
auto dist = connectionGraph(i, j);
if (std::isinf(dist)) {
std::vector<std::size_t> route;
if (!dijkstraAlgorithm(n, i, j, route, dist, distLambda)) {
std::stringstream ss;
ss << "Distance matrix calculation failed. connection graph: "
<< connectionGraph << std::endl;
ss << "area: " << bg::wkt(area) << std::endl;
ss << "transects:" << std::endl;
for (const auto &t : transects) {
ss << bg::wkt(t) << std::endl;
}
par.errorString = ss.str();
return false;
}
(void)route;
}
distanceMatrix(i, j) = dist;
distanceMatrix(j, i) = dist;
}
}
#ifdef SNAKE_DEBUG
std::cout << "distance matrix:" << std::endl;
std::cout << distanceMatrix << std::endl;
#endif
// Create (asymmetric) routing matrix.
Matrix<IntType> routingMatrix(nNodes, nNodes);
for (std::size_t i = 0; i < nNodes; ++i) {
auto fromNode = nodeList[i];
for (std::size_t j = 0; j < nNodes; ++j) {
auto toNode = nodeList[j];
routingMatrix(i, j) = distanceMatrix(fromNode.fromIndex, toNode.toIndex);
}
}
// Insert max for disjoint nodes.
for (const auto &d : disjointNodes) {
auto i = d.first;
auto j = d.second;
routingMatrix(i, j) = std::numeric_limits<IntType>::max();
routingMatrix(j, i) = std::numeric_limits<IntType>::max();
}
#ifdef SNAKE_DEBUG
std::cout << "routing matrix:" << std::endl;
std::cout << routingMatrix << std::endl;
#endif
// Create Routing Index Manager.
auto minNumTransectsPerRun =
std::max<std::size_t>(1, par.minNumTransectsPerRun);
auto maxRuns = std::max<std::size_t>(
1, std::floor(double(transects.size()) / minNumTransectsPerRun));
auto numRuns = std::max<std::size_t>(1, par.numRuns);
numRuns = std::min<std::size_t>(numRuns, maxRuns);
RoutingIndexManager::NodeIndex depot(0);
// std::vector<RoutingIndexManager::NodeIndex> depots(numRuns, depot);
// RoutingIndexManager manager(nNodes, numRuns, depots, depots);
RoutingIndexManager manager(nNodes, numRuns, depot);
// Create Routing Model.
RoutingModel routing(manager);
// Create and register a transit callback.
const int transitCallbackIndex = routing.RegisterTransitCallback(
[&routingMatrix, &manager](int64 from_index, int64 to_index) -> int64 {
// Convert from routing variable Index to distance matrix NodeIndex.
auto from_node = manager.IndexToNode(from_index).value();
auto to_node = manager.IndexToNode(to_index).value();
return routingMatrix(from_node, to_node);
});
// Define cost of each arc.
routing.SetArcCostEvaluatorOfAllVehicles(transitCallbackIndex);
// Add distance dimension.
if (numRuns > 1) {
routing.AddDimension(transitCallbackIndex, 0, 300000000,
true, // start cumul to zero
"Distance");
routing.GetMutableDimension("Distance")
->SetGlobalSpanCostCoefficient(100000000);
}
// Define disjunctions.
#ifdef SNAKE_DEBUG
std::cout << "disjunctions:" << std::endl;
#endif
for (const auto &d : disjointNodes) {
auto i = d.first;
auto j = d.second;
#ifdef SNAKE_DEBUG
std::cout << i << "," << j << std::endl;
#endif
auto idx0 = manager.NodeToIndex(RoutingIndexManager::NodeIndex(i));
auto idx1 = manager.NodeToIndex(RoutingIndexManager::NodeIndex(j));
std::vector<int64> disj{idx0, idx1};
routing.AddDisjunction(disj, -1 /*force cardinality*/, 1 /*cardinality*/);
}
// Set first solution heuristic.
auto searchParameters = DefaultRoutingSearchParameters();
searchParameters.set_first_solution_strategy(
FirstSolutionStrategy::PATH_CHEAPEST_ARC);
// Number of solutions.
auto numSolutionsPerRun = std::max<std::size_t>(1, par.numSolutionsPerRun);
searchParameters.set_number_of_solutions_to_collect(numSolutionsPerRun);
// Set costume limit.
auto *solver = routing.solver();
auto *limit = solver->MakeCustomLimit(par.stop);
routing.AddSearchMonitor(limit);
#ifdef SNAKE_SHOW_TIME
auto delta = std::chrono::duration_cast<std::chrono::milliseconds>(
std::chrono::high_resolution_clock::now() - start);
cout << "create routing model: " << delta.count() << " ms" << endl;
#endif
//================================================================
// Solve model.
//================================================================
#ifdef SNAKE_SHOW_TIME
start = std::chrono::high_resolution_clock::now();
#endif
auto pSolutions = std::make_unique<std::vector<const Assignment *>>();
(void)routing.SolveWithParameters(searchParameters, pSolutions.get());
#ifdef SNAKE_SHOW_TIME
delta = std::chrono::duration_cast<std::chrono::milliseconds>(
std::chrono::high_resolution_clock::now() - start);
cout << "solve routing model: " << delta.count() << " ms" << endl;
#endif
if (par.stop()) {
par.errorString = "User terminated.";
return false;
}
if (pSolutions->size() == 0) {
std::stringstream ss;
ss << "No solution found." << std::endl;
par.errorString = ss.str();
return false;
}
//================================================================
// Construc route.
//================================================================
#ifdef SNAKE_SHOW_TIME
start = std::chrono::high_resolution_clock::now();
#endif
long long counter = -1;
// Note: route number 0 corresponds to the best route which is the last entry
// of *pSolutions.
for (auto solution = pSolutions->end() - 1; solution >= pSolutions->begin();
--solution) {
++counter;
if (!*solution || (*solution)->Size() <= 1) {
std::stringstream ss;
ss << par.errorString << "Solution " << counter << "invalid."
<< std::endl;
par.errorString = ss.str();
continue;
}
// Iterate over all routes.
Solution routeVector;
for (std::size_t vehicle = 0; vehicle < numRuns; ++vehicle) {
if (!routing.IsVehicleUsed(**solution, vehicle))
continue;
// Create index list.
auto index = routing.Start(vehicle);
std::vector<size_t> route_idx;
route_idx.push_back(manager.IndexToNode(index).value());
while (!routing.IsEnd(index)) {
index = (*solution)->Value(routing.NextVar(index));
route_idx.push_back(manager.IndexToNode(index).value());
}
#ifdef SNAKE_DEBUG
// Print route.
std::cout << "route " << counter
<< " route_idx.size() = " << route_idx.size() << std::endl;
std::cout << "route: ";
for (const auto &idx : route_idx) {
std::cout << idx << ", ";
}
std::cout << std::endl;
#endif
if (route_idx.size() < 2) {
std::stringstream ss;
ss << par.errorString
<< "Error while assembling route (solution = " << counter
<< ", run = " << vehicle << ")." << std::endl;
par.errorString = ss.str();
continue;
}
// Assemble route.
Route r;
auto &path = r.path;
auto &info = r.info;
for (size_t i = 0; i < route_idx.size() - 1; ++i) {
size_t nodeIndex0 = route_idx[i];
size_t nodeIndex1 = route_idx[i + 1];
const auto &n2t0 = nodeToTransectList[nodeIndex0];
info.emplace_back(n2t0.transectsIndex, n2t0.reversed);
// Copy transect to route.
const auto &t = transects[n2t0.transectsIndex];
if (n2t0.reversed) { // transect reversal needed?
for (auto it = t.end() - 1; it > t.begin(); --it) {
path.push_back(*it);
}
} else {
for (auto it = t.begin(); it < t.end() - 1; ++it) {
path.push_back(*it);
}
}
// Connect transects.
std::vector<size_t> idxList;
if (!shortestPathFromGraph(connectionGraph,
nodeList[nodeIndex0].fromIndex,
nodeList[nodeIndex1].toIndex, idxList)) {
std::stringstream ss;
ss << par.errorString
<< "Error while assembling route (solution = " << counter
<< ", run = " << vehicle << ")." << std::endl;
par.errorString = ss.str();
continue;
}
if (i != route_idx.size() - 2) {
idxList.pop_back();
}
for (auto idx : idxList) {
auto p = int2Float(vertices[idx]);
path.push_back(p);
}
}
// Append last transect info.
const auto &n2t0 = nodeToTransectList.back();
info.emplace_back(n2t0.transectsIndex, n2t0.reversed);
if (path.size() < 2 || info.size() < 2) {
std::stringstream ss;
ss << par.errorString << "Route empty (solution = " << counter
<< ", run = " << vehicle << ")." << std::endl;
par.errorString = ss.str();
continue;
}
routeVector.push_back(std::move(r));
}
if (routeVector.size() > 0) {
solutionVector.push_back(std::move(routeVector));
} else {
std::stringstream ss;
ss << par.errorString << "Solution " << counter << " empty." << std::endl;
par.errorString = ss.str();
}
}
#ifdef SNAKE_SHOW_TIME
delta = std::chrono::duration_cast<std::chrono::milliseconds>(
std::chrono::high_resolution_clock::now() - start);
cout << "reconstruct route: " << delta.count() << " ms" << endl;
#endif
if (solutionVector.size() > 0) {
return true;
} else {
return false;
}
}