mapnik/test/unit/geometry/geometry_envelope_test.cpp

#include "catch.hpp"

#include <mapnik/geometry.hpp>
#include <mapnik/geometry/envelope.hpp>

namespace {

template<typename T>
void envelope_test()
{
    using namespace mapnik::geometry;
    using coord_type = T;

    {
        geometry<coord_type> geom(point<coord_type>(1, 2));
        mapnik::box2d<coord_type> bbox = mapnik::geometry::envelope(geom);
        REQUIRE(bbox.minx() == 1);
        REQUIRE(bbox.miny() == 2);
        REQUIRE(bbox.maxx() == 1);
        REQUIRE(bbox.maxy() == 2);
    }
    {
        // Test empty geom
        geometry<coord_type> geom = mapnik::geometry::geometry_empty();
        mapnik::box2d<coord_type> bbox = mapnik::geometry::envelope(geom);
        REQUIRE_FALSE(bbox.valid());
    }
    {
        line_string<coord_type> line;
        line.emplace_back(0, 0);
        line.emplace_back(1, 1);
        line.emplace_back(2, 2);
        geometry<coord_type> geom(line);
        mapnik::box2d<coord_type> bbox = mapnik::geometry::envelope(geom);
        REQUIRE(bbox.minx() == 0);
        REQUIRE(bbox.miny() == 0);
        REQUIRE(bbox.maxx() == 2);
        REQUIRE(bbox.maxy() == 2);
    }
    {
        line_string<coord_type> line;
        line.emplace_back(0, 0);
        line.emplace_back(1, 1);
        line.emplace_back(2, 2);
        line_string<coord_type> line2;
        line2.emplace_back(0, 0);
        line2.emplace_back(-1, -1);
        line2.emplace_back(-2, -2);
        multi_line_string<coord_type> multi_line;
        multi_line.emplace_back(std::move(line));
        multi_line.emplace_back(std::move(line2));
        geometry<coord_type> geom(multi_line);
        mapnik::box2d<coord_type> bbox = mapnik::geometry::envelope(geom);
        REQUIRE(bbox.minx() == -2);
        REQUIRE(bbox.miny() == -2);
        REQUIRE(bbox.maxx() == 2);
        REQUIRE(bbox.maxy() == 2);
    }
    {
        polygon<coord_type> poly;
        linear_ring<coord_type> ring;
        ring.emplace_back(0, 0);
        ring.emplace_back(-10, 0);
        ring.emplace_back(-10, 10);
        ring.emplace_back(0, 10);
        ring.emplace_back(0, 0);
        poly.push_back(std::move(ring));
        geometry<coord_type> geom(poly);
        mapnik::box2d<coord_type> bbox = mapnik::geometry::envelope(geom);
        REQUIRE(bbox.minx() == -10);
        REQUIRE(bbox.miny() == 0);
        REQUIRE(bbox.maxx() == 0);
        REQUIRE(bbox.maxy() == 10);

        multi_polygon<coord_type> mp;
        mp.push_back(poly);
        geometry<coord_type> geom_mp(mp);
        bbox = mapnik::geometry::envelope(geom_mp);
        REQUIRE(bbox.minx() == -10);
        REQUIRE(bbox.miny() == 0);
        REQUIRE(bbox.maxx() == 0);
        REQUIRE(bbox.maxy() == 10);

        geometry_collection<coord_type> gc;
        bbox = mapnik::geometry::envelope(gc);
        REQUIRE_FALSE(bbox.valid());
        gc.push_back(geom_mp);
        bbox = mapnik::geometry::envelope(gc);
        REQUIRE(bbox.minx() == -10);
        REQUIRE(bbox.miny() == 0);
        REQUIRE(bbox.maxx() == 0);
        REQUIRE(bbox.maxy() == 10);
        gc.emplace_back(point<coord_type>(-50, -50));
        bbox = mapnik::geometry::envelope(gc);
        REQUIRE(bbox.minx() == -50);
        REQUIRE(bbox.miny() == -50);
        REQUIRE(bbox.maxx() == 0);
        REQUIRE(bbox.maxy() == 10);
    }

    {
        // polygon with hole
        polygon<coord_type> poly;
        linear_ring<coord_type> ring;
        ring.emplace_back(0, 0);
        ring.emplace_back(-10, 0);
        ring.emplace_back(-10, 10);
        ring.emplace_back(0, 10);
        ring.emplace_back(0, 0);
        poly.push_back(std::move(ring));
        linear_ring<coord_type> hole;
        hole.emplace_back(-7, 7);
        hole.emplace_back(-7, 3);
        hole.emplace_back(-3, 3);
        hole.emplace_back(-3, 7);
        hole.emplace_back(-7, 7);
        poly.push_back(std::move(hole));
        geometry<coord_type> geom(poly);
        mapnik::box2d<coord_type> bbox = mapnik::geometry::envelope(poly);
        REQUIRE(bbox.minx() == -10);
        REQUIRE(bbox.miny() == 0);
        REQUIRE(bbox.maxx() == 0);
        REQUIRE(bbox.maxy() == 10);
        // add another hole inside the first hole
        // which should be considered a hit
        linear_ring<coord_type> fill;
        fill.emplace_back(-6, 4);
        fill.emplace_back(-6, 6);
        fill.emplace_back(-4, 6);
        fill.emplace_back(-4, 4);
        fill.emplace_back(-6, 4);
        poly.push_back(std::move(fill));
        bbox = mapnik::geometry::envelope(poly);
        REQUIRE(bbox.minx() == -10);
        REQUIRE(bbox.miny() == 0);
        REQUIRE(bbox.maxx() == 0);
        REQUIRE(bbox.maxy() == 10);
    }
}

} // namespace

TEST_CASE("geometry ops - envelope")
{
    SECTION("envelope_test")
    {
        envelope_test<int>();
        envelope_test<double>();
        envelope_test<float>();
    }
}