mapnik/test/unit/geometry/polygon_vertex_processor.cpp

#include "catch.hpp"
#include "unit/vertex_adapter/fake_path.hpp"

#include <mapnik/geometry/polygon_vertex_processor.hpp>

TEST_CASE("polygon_vertex_processor")
{
    SECTION("empty polygon")
    {
        fake_path path = {};
        mapnik::geometry::polygon_vertex_processor<double> proc;
        proc.add_path(path);
        CHECK(proc.polygon_.size() == 0);
    }

    SECTION("empty outer ring")
    {
        fake_path path = {};
        path.vertices_.emplace_back(0, 0, mapnik::SEG_CLOSE);
        path.rewind(0);

        mapnik::geometry::polygon_vertex_processor<double> proc;
        proc.add_path(path);
        REQUIRE(proc.polygon_.size() == 1);
        REQUIRE(proc.polygon_.front().size() == 0);
    }

    SECTION("empty inner ring")
    {
        fake_path path = {};
        path.vertices_.emplace_back(-1, -1, mapnik::SEG_MOVETO);
        path.vertices_.emplace_back(1, -1, mapnik::SEG_LINETO);
        path.vertices_.emplace_back(1, 1, mapnik::SEG_LINETO);
        path.vertices_.emplace_back(-1, 1, mapnik::SEG_LINETO);
        path.vertices_.emplace_back(0, 0, mapnik::SEG_CLOSE);
        path.vertices_.emplace_back(0, 0, mapnik::SEG_CLOSE);
        path.rewind(0);

        mapnik::geometry::polygon_vertex_processor<double> proc;
        proc.add_path(path);

        REQUIRE(proc.polygon_.size() == 2);
        auto const& outer_ring = proc.polygon_.front();
        REQUIRE(outer_ring.size() == 5);

        CHECK(outer_ring[0].x == Approx(-1));
        CHECK(outer_ring[0].y == Approx(-1));

        CHECK(outer_ring[1].x == Approx(1));
        CHECK(outer_ring[1].y == Approx(-1));

        CHECK(outer_ring[2].x == Approx(1));
        CHECK(outer_ring[2].y == Approx(1));

        CHECK(outer_ring[3].x == Approx(-1));
        CHECK(outer_ring[3].y == Approx(1));

        CHECK(outer_ring[4].x == Approx(-1));
        CHECK(outer_ring[4].y == Approx(-1));
    }
}