在 Boost Graph Library 中向网格的顶点添加自定义属性

Question

我在我的机器人项目中使用 Boost Graph Library 进行地图管理。我打算使用 Boost Grid，但我发现 Boost Graph 文档真的很难理解，所以我需要一点帮助。

这是我创建网格并打印它的方式：

  struct sampleVertex {
    int row;
    int col;
    bool occupied;
  };

  boost::array<std::size_t, 2> lengths = { { 3, 2 } };
  boost::grid_graph<2> gridD(lengths);
  boost::write_graphviz(fout, gridD);

现在，我想将自定义属性添加到顶点，定义为结构 - 'sampleVertex'。请给我看一些代码 sn-p 或示例来执行此操作。我知道，可以通过 adjacency_list 添加捆绑的属性并手动创建网格顶点和连接边。我想知道，是否可以直接使用 boost::grid_graph 来完成。提前致谢。

Answer 1

这是我能想到的一个简单示例（它也使用了输出中的属性）：

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#include <boost/graph/grid_graph.hpp>
#include <boost/graph/properties.hpp>
#include <boost/graph/graphviz.hpp>
#include <iostream>

struct sampleVertex {
    int row;
    int col;
    bool occupied;
    friend std::ostream& operator<<(std::ostream& os, sampleVertex& sv) {
        return os << "{" << sv.row << "," << sv.col << "," << sv.occupied << "}";
    }
    friend std::istream& operator>>(std::istream& is, sampleVertex& sv) {
        return is >> sv.row >> sv.col >> sv.occupied;
    }
};


int main() {
    boost::array<int, 2> lengths = { { 3, 2 } };
    using Graph  = boost::grid_graph<2, int>;
    using Traits = boost::graph_traits<Graph>;
    using IdMap  = boost::property_map<Graph, boost::vertex_index_t>::const_type;

    Graph gridD(lengths);
    IdMap indexMap(get(boost::vertex_index, gridD));
    // properties
    boost::vector_property_map<sampleVertex, IdMap> props(num_vertices(gridD), indexMap);

    // initialize
    for (int i = 0; i < 3; ++i)
        for (int j = 0; j < 2; ++j)
            put(props, Traits::vertex_descriptor {{i, j}}, sampleVertex{i,j,false});

    // print a property
    boost::dynamic_properties dp;
    dp.property("node_id", props);
    boost::write_graphviz_dp(std::cout, gridD, dp);
}

输出：

digraph G {
"{0,0,0}";
"{1,0,0}";
"{2,0,0}";
"{0,1,0}";
"{1,1,0}";
"{2,1,0}";
"{0,0,0}"->"{1,0,0}" ;
"{1,0,0}"->"{2,0,0}" ;
"{0,1,0}"->"{1,1,0}" ;
"{1,1,0}"->"{2,1,0}" ;
"{1,0,0}"->"{0,0,0}" ;
"{2,0,0}"->"{1,0,0}" ;
"{1,1,0}"->"{0,1,0}" ;
"{2,1,0}"->"{1,1,0}" ;
"{0,0,0}"->"{0,1,0}" ;
"{1,0,0}"->"{1,1,0}" ;
"{2,0,0}"->"{2,1,0}" ;
"{0,1,0}"->"{0,0,0}" ;
"{1,1,0}"->"{1,0,0}" ;
"{2,1,0}"->"{2,0,0}" ;
}