mapnik/test/unit/datasource/topojson.cpp

/*****************************************************************************
 *
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2016 Artem Pavlenko
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *****************************************************************************/

#include "catch.hpp"

#include <mapnik/util/fs.hpp>
#include <mapnik/util/file_io.hpp>
#include <mapnik/json/topology.hpp>
#include <mapnik/json/topojson_grammar.hpp>
#include <mapnik/json/topojson_utils.hpp>

namespace {

using iterator_type = std::string::const_iterator;
const mapnik::topojson::topojson_grammar<iterator_type> grammar;

bool parse_topology(std::string const& filename, mapnik::topojson::topology & topo)
{
    mapnik::util::file file(filename);
    std::string buffer;
    buffer.resize(file.size());
    std::fread(&buffer[0], buffer.size(), 1, file.get());
    if (!file) return false;
    boost::spirit::standard::space_type space;
    iterator_type itr = buffer.begin();
    iterator_type end = buffer.end();
    bool result = boost::spirit::qi::phrase_parse(itr, end, grammar, space, topo);
    return (result && (itr == end));
}


}

TEST_CASE("topology")
{
    SECTION("geometry parsing")
    {
        mapnik::value_integer feature_id = 0;
        mapnik::context_ptr ctx = std::make_shared<mapnik::context_type>();
        mapnik::transcoder tr("utf8");
        for (auto const& path : mapnik::util::list_directory("test/data/topojson/"))
        {
            mapnik::topojson::topology topo;
            REQUIRE(parse_topology(path, topo));
            for (auto const& geom : topo.geometries)
            {
                mapnik::box2d<double> bbox = mapnik::util::apply_visitor(mapnik::topojson::bounding_box_visitor(topo), geom);
                CHECK(bbox.valid());
                mapnik::topojson::feature_generator<mapnik::context_ptr> visitor(ctx, tr, topo, feature_id++);
                mapnik::feature_ptr feature = mapnik::util::apply_visitor(visitor, geom);
                CHECK(feature);
                CHECK(feature->envelope() == bbox);
            }
        }
    }
}