boost_graph.cpp

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#include <boost_graph.h>
 
#include <graph.h>
#include <node.h>
#include <Edge.h>
#include <assert.h>
 
using HF::SpatialStructures::Graph;
using HF::SpatialStructures::Node;
using std::vector;
using std::string;
 
namespace HF::Pathfinding {
 
 
    BoostGraph::BoostGraph(const Graph& graph, const string & cost_type)
    {
 
        // Allocate a vector of integers with an element for every node in
        // nodes.
        int num_nodes = graph.size();
        vector<int> nodes(num_nodes);
 
        std::vector<pair> edges;
        std::vector<Edge_Cost> weights;
 
        // Get a set of all edges from the graph with the passed cost type.
        // This will return the set of costs that the graph was constructed
        // with in the case that no cost_type was specified.
        auto edge_sets = graph.GetEdges(cost_type);
 
        // Iterate through every set of edges to convert them 
        // to a format usable with Boost
        for (const auto& edgeset : edge_sets) {
            const int parent_id = edgeset.parent;
 
            // Iterate through all children of this parent
            for (const auto& edge : edgeset.children) {
                
                // Add the edge to the boost graph's edge array and the weight
                // to the boost graph's weights array
                int child_id = edge.child;
                float cost = edge.weight;
                weights.emplace_back(Edge_Cost{ edge.weight });
                edges.emplace_back(pair{ parent_id,child_id });
            }
        }
 
        // Calculate the maximum id held by the graph.
        unsigned int max_node = graph.MaxID() + 1;
 
        // Create the boost graph from the two input arrays
        g = graph_t(boost::edges_are_unsorted, edges.begin(), edges.end(), weights.begin(), max_node);
 
        int n = num_vertices(g);
 
        // Resize predecessor and distance arrays to maximum size.
        p.resize(n);
        d.resize(n);
    }
 
    BoostGraph::~BoostGraph() = default;
}