mapnik/test/unit/geometry/centroid.cpp

#include "catch.hpp"

#include <mapnik/geometry/centroid.hpp>

TEST_CASE("geometry centroid")
{
    SECTION("empty geometry")
    {
        mapnik::geometry::geometry_empty geom;
        mapnik::geometry::point<double> centroid;
        REQUIRE(!mapnik::geometry::centroid(geom, centroid));
    }

    SECTION("geometry collection")
    {
        mapnik::geometry::geometry_collection<double> geom;
        mapnik::geometry::point<double> centroid;
        REQUIRE(!mapnik::geometry::centroid(geom, centroid));
    }

    SECTION("point")
    {
        mapnik::geometry::point<double> pt(10, 10);
        mapnik::geometry::point<double> centroid;
        REQUIRE(mapnik::geometry::centroid(pt, centroid));
        REQUIRE(pt.x == centroid.x);
        REQUIRE(pt.y == centroid.y);
    }

    SECTION("linestring")
    {
        mapnik::geometry::line_string<double> line;
        line.emplace_back(0, 0);
        line.emplace_back(25, 25);
        line.emplace_back(50, 50);
        mapnik::geometry::point<double> centroid;
        REQUIRE(mapnik::geometry::centroid(line, centroid));
        REQUIRE(centroid.x == 25);
        REQUIRE(centroid.y == 25);
    }

    SECTION("empty linestring")
    {
        mapnik::geometry::line_string<double> line;
        mapnik::geometry::point<double> centroid;
        REQUIRE(!mapnik::geometry::centroid(line, centroid));
    }

    SECTION("polygon")
    {
        mapnik::geometry::polygon<double> poly;
        mapnik::geometry::linear_ring<double> ring;
        ring.emplace_back(0, 0);
        ring.emplace_back(1, 0);
        ring.emplace_back(1, 1);
        ring.emplace_back(0, 1);
        ring.emplace_back(0, 0);
        poly.push_back(std::move(ring));

        mapnik::geometry::point<double> centroid;
        REQUIRE(mapnik::geometry::centroid(poly, centroid));
        REQUIRE(centroid.x == 0.5);
        REQUIRE(centroid.y == 0.5);
    }

    SECTION("polygon with empty exterior ring")
    {
        mapnik::geometry::polygon<double> poly;
        mapnik::geometry::linear_ring<double> ring;
        poly.push_back(std::move(ring));

        mapnik::geometry::point<double> centroid;
        REQUIRE(!mapnik::geometry::centroid(poly, centroid));
    }

    SECTION("empty polygon")
    {
        mapnik::geometry::polygon<double> poly;
        poly.emplace_back();
        mapnik::geometry::point<double> centroid;
        REQUIRE(!mapnik::geometry::centroid(poly, centroid));
    }

    SECTION("multi-point")
    {
        mapnik::geometry::multi_point<double> geom;
        geom.emplace_back(0, 0);
        geom.emplace_back(25, 25);
        geom.emplace_back(50, 50);
        mapnik::geometry::point<double> centroid;
        REQUIRE(mapnik::geometry::centroid(geom, centroid));
        REQUIRE(centroid.x == 25);
        REQUIRE(centroid.y == 25);
    }

    SECTION("empty multi-point")
    {
        mapnik::geometry::multi_point<double> geom;
        mapnik::geometry::point<double> centroid;
        REQUIRE(!mapnik::geometry::centroid(geom, centroid));
    }

    SECTION("multi-linestring")
    {
        mapnik::geometry::multi_line_string<double> geom;
        {
            mapnik::geometry::line_string<double> line;
            line.emplace_back(0, 0);
            line.emplace_back(0, 25);
            line.emplace_back(0, 50);
            geom.emplace_back(std::move(line));
        }
        {
            mapnik::geometry::line_string<double> line;
            line.emplace_back(0, 0);
            line.emplace_back(25, 0);
            line.emplace_back(50, 0);
            geom.emplace_back(std::move(line));
        }
        mapnik::geometry::point<double> centroid;
        REQUIRE(mapnik::geometry::centroid(geom, centroid));
        REQUIRE(centroid.x == 12.5);
        REQUIRE(centroid.y == 12.5);
    }

    SECTION("multi-linestring: one component empty")
    {
        mapnik::geometry::multi_line_string<double> geom;
        mapnik::geometry::line_string<double> line;
        line.emplace_back(0, 0);
        line.emplace_back(0, 25);
        line.emplace_back(0, 50);
        geom.emplace_back(std::move(line));
        geom.emplace_back();
        mapnik::geometry::point<double> centroid;
        REQUIRE(mapnik::geometry::centroid(geom, centroid));
        REQUIRE(centroid.x == 0);
        REQUIRE(centroid.y == 25);
    }

    SECTION("empty multi-linestring")
    {
        mapnik::geometry::multi_line_string<double> geom;
        mapnik::geometry::point<double> centroid;
        REQUIRE(!mapnik::geometry::centroid(geom, centroid));
    }

    SECTION("multi-polygon")
    {
        mapnik::geometry::multi_polygon<double> geom;
        {
            mapnik::geometry::polygon<double> poly;
            mapnik::geometry::linear_ring<double> ring;
            ring.emplace_back(0, 0);
            ring.emplace_back(1, 0);
            ring.emplace_back(1, 1);
            ring.emplace_back(0, 1);
            ring.emplace_back(0, 0);
            poly.push_back(std::move(ring));
            geom.emplace_back(std::move(poly));
        }
        {
            mapnik::geometry::polygon<double> poly;
            mapnik::geometry::linear_ring<double> ring;
            ring.emplace_back(1, 1);
            ring.emplace_back(2, 1);
            ring.emplace_back(2, 2);
            ring.emplace_back(1, 2);
            ring.emplace_back(1, 1);
            poly.push_back(std::move(ring));
            geom.emplace_back(std::move(poly));
        }

        mapnik::geometry::point<double> centroid;
        REQUIRE(mapnik::geometry::centroid(geom, centroid));
        REQUIRE(centroid.x == 1);
        REQUIRE(centroid.y == 1);
    }

    SECTION("multi-polygon: one component empty")
    {
        mapnik::geometry::multi_polygon<double> geom;
        mapnik::geometry::polygon<double> poly;
        mapnik::geometry::linear_ring<double> ring;
        ring.emplace_back(0, 0);
        ring.emplace_back(1, 0);
        ring.emplace_back(1, 1);
        ring.emplace_back(0, 1);
        ring.emplace_back(0, 0);
        poly.push_back(std::move(ring));
        geom.emplace_back(std::move(poly));
        geom.emplace_back();
        geom.back().emplace_back();
        mapnik::geometry::point<double> centroid;
        REQUIRE(mapnik::geometry::centroid(geom, centroid));
        REQUIRE(centroid.x == 0.5);
        REQUIRE(centroid.y == 0.5);
    }

    SECTION("empty multi-polygon")
    {
        mapnik::geometry::multi_polygon<double> geom;
        mapnik::geometry::point<double> centroid;
        REQUIRE(!mapnik::geometry::centroid(geom, centroid));
    }
}