C++ code sample using libosmium

get-trees.cpp

/*

To build:

git clone [email protected]:osmcode/libosmium.git
clang++ -o get-trees get-trees.cpp -O3 -DNDEBUG -I./libosmium/include -std=c++11 -lz
./get-trees

*/


// C++ API docs: http://docs.osmcode.org/libosmium-manual/

#include <exception>
#include <vector>
#include <iostream>


#include <osmium/handler.hpp>
#include <osmium/io/pbf_input.hpp>
#include <osmium/visitor.hpp>


class TreeHandler : public osmium::handler::Handler {
  public:
    TreeHandler() {
    }

    void node(const osmium::Node& node) {
        auto const& tags = node.tags();
        const char * natural_char = tags.get_value_by_key("natural");
        if (natural_char) {
            std::string natural = std::string(natural_char);
            if (!natural.empty() && natural == "tree") {
                auto const& location = node.location();
                std::clog << location.lon() << "," << location.lat() << "\n";
            }            
        }
    }
};


int main(int argc, char** argv)
{
    std::vector<std::string> args;
    for (int i=1;i<argc;++i)
    {
        args.push_back(argv[i]);
    }
    
    if (args.empty())
    {
        std::clog << "please pass the path to an osm pbf file\n";
        return -1;
    }
    
    try
    {
        std::string filename = args[0];
        osmium::io::Reader reader(filename);
        TreeHandler handler;
        osmium::apply(reader, handler);
        reader.close();
    }
    catch (std::exception const& ex)
    {
        std::clog << "error: " << ex.what() << "\n";
        return -1;
    }
}