geometry/test/algorithms/simplify_countries.cpp

189 lines
7.2 KiB
C++

// Boost.Geometry (aka GGL, Generic Geometry Library)
// (Unit) Test
// Copyright (c) 2018 Barend Gehrels, Amsterdam, the Netherlands.
// Use, modification and distribution is subject to the Boost Software License,
// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
#include <boost/geometry.hpp>
#include <geometry_test_common.hpp>
#include <boost/foreach.hpp>
#include <iomanip>
#if defined(TEST_WITH_SVG)
# include <boost/geometry/io/svg/svg_mapper.hpp>
#endif
template <typename MultiPolygon>
std::string read_from_file(std::string const& filename)
{
MultiPolygon mp;
std::ifstream in(filename.c_str());
while (in.good())
{
std::string line;
std::getline(in, line);
if (! line.empty())
{
typename boost::range_value<MultiPolygon>::type pol;
bg::read_wkt(line, pol);
mp.push_back(pol);
}
}
std::ostringstream out;
if (! mp.empty())
{
out << std::fixed << std::setprecision(19) << bg::wkt(mp);
}
BOOST_CHECK(! out.str().empty());
return out.str();
}
template <typename MultiPolygon>
void test_one(std::string const& caseid, std::string const& wkt,
double distance_in_meters,
double expected_area_ratio, double expected_perimeter_ratio,
std::size_t expected_polygon_count = 0,
std::size_t expected_interior_count = 0,
std::size_t expected_point_count = 0)
{
boost::ignore_unused(caseid);
MultiPolygon geometry, simplified;
bg::read_wkt(wkt, geometry);
bg::correct(geometry);
bg::simplify(geometry, simplified, distance_in_meters);
double const area_ratio = bg::area(simplified) / bg::area(geometry);
double const perimeter_ratio = bg::perimeter(simplified) / bg::perimeter(geometry);
BOOST_CHECK_CLOSE(perimeter_ratio, expected_perimeter_ratio, 0.01);
BOOST_CHECK_CLOSE(area_ratio, expected_area_ratio, 0.01);
BOOST_CHECK_EQUAL(expected_polygon_count, boost::size(simplified));
BOOST_CHECK_EQUAL(expected_interior_count, bg::num_interior_rings(simplified));
BOOST_CHECK_EQUAL(expected_point_count, bg::num_points(simplified));
// To add new tests, this is convenient and write the test itself:
// std::cout << "test_one<mp>(\"" << caseid << "\", " << caseid
// << ", " << distance_in_meters
// << std::setprecision(6)
// << ", " << area_ratio
// << ", " << perimeter_ratio
// << ", " << boost::size(simplified)
// << ", " << bg::num_interior_rings(simplified)
// << ", " << bg::num_points(simplified)
// << ");"
// << std::endl;
#if defined(TEST_WITH_SVG)
{
typedef typename boost::range_value<MultiPolygon>::type polygon;
std::ostringstream filename;
filename << "simplify_" << caseid << "_" << distance_in_meters << ".svg";
std::ofstream svg(filename.str().c_str());
bg::svg_mapper
<
typename bg::point_type<MultiPolygon>::type
> mapper(svg, 1200, 800);
mapper.add(geometry);
mapper.add(simplified);
mapper.map(geometry, "fill-opacity:0.5;fill:rgb(153,204,0);"
"stroke:rgb(153,204,0);stroke-width:1");
BOOST_FOREACH(polygon const& pol, simplified)
{
mapper.map(pol,
bg::area(pol) > 0 ? "fill:none;stroke:rgb(255,0,0);stroke-width:1"
: "fill:none;stroke:rgb(255,0,255);stroke-width:1");
}
}
#endif
}
template <bool Clockwise, typename P>
void test_all()
{
typedef bg::model::polygon<P, Clockwise> polygon;
typedef bg::model::multi_polygon<polygon> mp;
// The unit test uses countries originally added for buffer unit test
std::string base_folder = "buffer/data/";
// Verify for Greece, Italy, Netherlands, Norway and UK
std::string gr = read_from_file<mp>(base_folder + "gr.wkt");
std::string it = read_from_file<mp>(base_folder + "it.wkt");
std::string nl = read_from_file<mp>(base_folder + "nl.wkt");
std::string no = read_from_file<mp>(base_folder + "no.wkt");
std::string uk = read_from_file<mp>(base_folder + "uk.wkt");
// Gradually simplify more aggresively.
// Area ratio (first) can increase or decrease
// Perimeter ratio (second) should decrease.
// Polygons, interior rings, points should decrease
test_one<mp>("gr", gr, 100, 0.999891, 0.999756, 68, 0, 2519);
test_one<mp>("gr", gr, 200, 0.999733, 0.998884, 68, 0, 2021);
test_one<mp>("gr", gr, 500, 0.999055, 0.995767, 68, 0, 1470);
test_one<mp>("gr", gr, 1000, 0.997767, 0.991097, 68, 0, 1139);
test_one<mp>("gr", gr, 2000, 0.994679, 0.976902, 65, 0, 852);
test_one<mp>("gr", gr, 5000, 0.980616, 0.89164, 45, 0, 450);
test_one<mp>("gr", gr, 10000, 0.96915, 0.767563, 25, 0, 229);
test_one<mp>("gr", gr, 20000, 0.937931, 0.579678, 8, 0, 90); // Many islands disappear
test_one<mp>("it", it, 100, 1, 0.999812, 22, 1, 1781);
test_one<mp>("it", it, 200, 1.00009, 0.999088, 22, 1, 1398);
test_one<mp>("it", it, 500, 1.0002, 0.996893, 22, 1, 1005);
test_one<mp>("it", it, 1000, 1.00053, 0.993039, 22, 1, 747);
test_one<mp>("it", it, 2000, 1.00087, 0.984379, 22, 1, 547);
test_one<mp>("it", it, 5000, 1.00174, 0.928495, 8, 1, 272);
test_one<mp>("it", it, 10000, 1.01316, 0.880268, 4, 1, 151);
test_one<mp>("it", it, 20000, 1.00764, 0.824566, 4, 0, 87); // San Marino disappears
test_one<mp>("nl", nl, 100, 0.999889, 0.999814, 8, 0, 796);
test_one<mp>("nl", nl, 200, 0.999627, 0.999074, 8, 0, 631);
test_one<mp>("nl", nl, 500, 0.999208, 0.996389, 8, 0, 434);
test_one<mp>("nl", nl, 1000, 0.998292, 0.991971, 8, 0, 329);
test_one<mp>("nl", nl, 2000, 0.995699, 0.981222, 8, 0, 235);
test_one<mp>("nl", nl, 5000, 0.993008, 0.915048, 6, 0, 135);
test_one<mp>("nl", nl, 10000, 0.978084, 0.80839, 3, 0, 69);
test_one<mp>("nl", nl, 20000, 0.976826, 0.73938, 3, 0, 41);
test_one<mp>("no", no, 100, 0.999966, 0.999976, 95, 0, 7653);
test_one<mp>("no", no, 200, 0.999819, 0.999732, 95, 0, 6527);
test_one<mp>("no", no, 500, 0.999303, 0.99808, 95, 0, 4725);
test_one<mp>("no", no, 1000, 0.998466, 0.993979, 95, 0, 3517);
test_one<mp>("no", no, 2000, 0.996415, 0.985417, 92, 0, 2572);
test_one<mp>("no", no, 5000, 0.990913, 0.962711, 86, 0, 1671);
test_one<mp>("no", no, 10000, 0.975975, 0.900398, 66, 0, 1045);
test_one<mp>("no", no, 20000, 0.954832, 0.767641, 33, 0, 575);
test_one<mp>("uk", uk, 100, 0.999948, 0.999879, 48, 0, 3214);
test_one<mp>("uk", uk, 200, 0.99985, 0.999288, 48, 0, 2614);
test_one<mp>("uk", uk, 500, 0.999535, 0.996913, 48, 0, 1882);
test_one<mp>("uk", uk, 1000, 0.998906, 0.991917, 48, 0, 1383);
test_one<mp>("uk", uk, 2000, 0.998059, 0.984074, 48, 0, 1042);
test_one<mp>("uk", uk, 5000, 0.991533, 0.941306, 36, 0, 608);
test_one<mp>("uk", uk, 10000, 0.990376, 0.87048, 23, 0, 361);
test_one<mp>("uk", uk, 20000, 0.977764, 0.719399, 10, 0, 182);
}
int test_main(int, char* [])
{
test_all<true, bg::model::point<double, 2, bg::cs::cartesian> >();
return 0;
}