Add num_geometries(), geometry_type(), and centroid() functions

Tests are split up by geometry type and there are additional tests.

Author: joto

src/geom-functions.cpp

@@ -7,6 +7,7 @@
  * For a full list of authors see the git log.
  */
 
+#include "geom-boost-adaptor.hpp"
 #include "geom-functions.hpp"
 
 #include <algorithm>
@@ -30,6 +31,32 @@ point_t interpolate(point_t p1, point_t p2, double frac) noexcept
                    frac * (p1.y() - p2.y()) + p2.y()};
 }
 
+std::string_view geometry_type(geometry_t const &geom)
+{
+    using namespace std::literals::string_view_literals;
+    return geom.visit(overloaded{
+        [&](geom::nullgeom_t const & /*input*/) { return "NULL"sv; },
+        [&](geom::point_t const & /*input*/) { return "POINT"sv; },
+        [&](geom::linestring_t const & /*input*/) { return "LINESTRING"sv; },
+        [&](geom::polygon_t const & /*input*/) { return "POLYGON"sv; },
+        [&](geom::multipoint_t const & /*input*/) { return "MULTIPOINT"sv; },
+        [&](geom::multilinestring_t const & /*input*/) {
+            return "MULTILINESTRING"sv;
+        },
+        [&](geom::multipolygon_t const & /*input*/) {
+            return "MULTIPOLYGON"sv;
+        },
+        [&](geom::collection_t const & /*input*/) {
+            return "GEOMETRYCOLLECTION"sv;
+        }});
+}
+
+std::size_t num_geometries(geometry_t const &geom)
+{
+    return geom.visit(
+        overloaded{[&](auto const &input) { return input.num_geometries(); }});
+}
+
 namespace {
 
 class transform_visitor
@@ -519,4 +546,19 @@ geometry_t line_merge(geometry_t geom)
     return output;
 }
 
+geometry_t centroid(geometry_t const &geom)
+{
+    geom::geometry_t output{point_t{}, geom.srid()};
+    auto &center = output.get<point_t>();
+
+    geom.visit(overloaded{
+        [&](geom::nullgeom_t const & /*input*/) { output.reset(); },
+        [&](geom::collection_t const & /*input*/) {
+            throw std::runtime_error{"not implemented yet"};
+        },
+        [&](auto const &input) { boost::geometry::centroid(input, center); }});
+
+    return output;
+}
+
 } // namespace geom

src/geom-functions.hpp

@@ -13,6 +13,7 @@
 #include "geom.hpp"
 #include "reprojection.hpp"
 
+#include <string_view>
 #include <utility>
 #include <vector>
 
@@ -51,6 +52,18 @@ void for_each_segment(point_list_t const &list, FUNC&& func)
     }
 }
 
+/**
+ * Return the type of a geometry as string: NULL, (MULTI)POINT,
+ * (MULTI)LINESTRING, (MULTI)POLYGON, or GEOMETRYCOLLECTION.
+ */
+std::string_view geometry_type(geometry_t const &geom);
+
+/**
+ * Return the number of geometries in this geometry. For the null geometry
+ * this is always 0, for other non-multi geometries this is always 1.
+ */
+std::size_t num_geometries(geometry_t const &geom);
+
 /**
  * Transform a geometry in 4326 into some other projection.
  *
@@ -105,6 +118,14 @@ std::vector<geometry_t> split_multi(geometry_t geom, bool split_multi = true);
  */
 geometry_t line_merge(geometry_t geom);
 
+/**
+ * Calculate the centroid of a geometry.
+ *
+ * \param geom Input geometry.
+ * \returns Resulting point geometry.
+ */
+geometry_t centroid(geometry_t const &geom);
+
 } // namespace geom
 
 #endif // OSM2PGSQL_GEOM_FUNCTIONS_HPP

tests/CMakeLists.txt

@@ -42,8 +42,10 @@ set_test(test-db-copy-thread)
 set_test(test-db-copy-mgr)
 set_test(test-domain-matcher LABELS NoDB)
 set_test(test-expire-tiles LABELS NoDB)
-set_test(test-geom LABELS NoDB)
 set_test(test-geom-box LABELS NoDB)
+set_test(test-geom-lines LABELS NoDB)
+set_test(test-geom-null LABELS NoDB)
+set_test(test-geom-points LABELS NoDB)
 set_test(test-middle)
 set_test(test-node-locations LABELS NoDB)
 set_test(test-options-database LABELS NoDB)

tests/test-geom.cpp tests/test-geom-lines.cpptests/test-geom.cpp renamed to tests/test-geom-lines.cpp

@@ -14,39 +14,9 @@
 #include "geom-from-osm.hpp"
 #include "geom-functions.hpp"
 #include "geom.hpp"
-#include "reprojection.hpp"
 
 #include <array>
 
-TEST_CASE("geom::distance", "[NoDB]")
-{
-    geom::point_t const p1{10, 10};
-    geom::point_t const p2{20, 10};
-    geom::point_t const p3{13, 14};
-
-    REQUIRE(geom::distance(p1, p1) == Approx(0.0));
-    REQUIRE(geom::distance(p1, p2) == Approx(10.0));
-    REQUIRE(geom::distance(p1, p3) == Approx(5.0));
-}
-
-TEST_CASE("geom::interpolate", "[NoDB]")
-{
-    geom::point_t const p1{10, 10};
-    geom::point_t const p2{20, 10};
-
-    auto const i1 = geom::interpolate(p1, p1, 0.5);
-    REQUIRE(i1.x() == 10);
-    REQUIRE(i1.y() == 10);
-
-    auto const i2 = geom::interpolate(p1, p2, 0.5);
-    REQUIRE(i2.x() == 15);
-    REQUIRE(i2.y() == 10);
-
-    auto const i3 = geom::interpolate(p2, p1, 0.5);
-    REQUIRE(i3.x() == 15);
-    REQUIRE(i3.y() == 10);
-}
-
 TEST_CASE("geom::linestring_t", "[NoDB]")
 {
     geom::linestring_t ls1;
@@ -64,6 +34,18 @@ TEST_CASE("geom::linestring_t", "[NoDB]")
     REQUIRE(it->y() == 22);
     ++it;
     REQUIRE(it == ls1.cend());
+
+    REQUIRE(ls1.num_geometries() == 1);
+}
+
+TEST_CASE("line geometry", "[NoDB]")
+{
+    geom::geometry_t const geom{geom::linestring_t{{1, 1}, {2, 2}}};
+
+    REQUIRE(num_geometries(geom) == 1);
+    REQUIRE(area(geom) == Approx(0.0));
+    REQUIRE(geometry_type(geom) == "LINESTRING");
+    REQUIRE(centroid(geom) == geom::geometry_t{geom::point_t{1.5, 1.5}});
 }
 
 TEST_CASE("geom::segmentize w/o split", "[NoDB]")
@@ -73,6 +55,7 @@ TEST_CASE("geom::segmentize w/o split", "[NoDB]")
     auto const geom = geom::segmentize(geom::geometry_t{line}, 10.0);
 
     REQUIRE(geom.is_multilinestring());
+    REQUIRE(num_geometries(geom) == 1);
     auto const &ml = geom.get<geom::multilinestring_t>();
     REQUIRE(ml.num_geometries() == 1);
     REQUIRE(ml[0] == line);
@@ -182,6 +165,9 @@ TEST_CASE("create_multilinestring with single line", "[NoDB]")
         geom::line_merge(geom::create_multilinestring(buffer.buffer()));
 
     REQUIRE(geom.is_multilinestring());
+    REQUIRE(geometry_type(geom) == "MULTILINESTRING");
+    REQUIRE(num_geometries(geom) == 1);
+    REQUIRE(area(geom) == Approx(0.0));
     auto const &ml = geom.get<geom::multilinestring_t>();
     REQUIRE(ml.num_geometries() == 1);
     REQUIRE(ml[0] == expected);

tests/test-geom-null.cpp

@@ -0,0 +1,24 @@
+/**
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * This file is part of osm2pgsql (https://osm2pgsql.org/).
+ *
+ * Copyright (C) 2006-2022 by the osm2pgsql developer community.
+ * For a full list of authors see the git log.
+ */
+
+#include <catch.hpp>
+
+#include "geom-from-osm.hpp"
+#include "geom-functions.hpp"
+#include "geom.hpp"
+
+TEST_CASE("null geometry", "[NoDB]")
+{
+    geom::geometry_t const geom{};
+
+    REQUIRE(num_geometries(geom) == 0);
+    REQUIRE(area(geom) == 0.0);
+    REQUIRE(geometry_type(geom) == "NULL");
+    REQUIRE(centroid(geom).is_null());
+}

tests/test-geom-points.cpp

@@ -0,0 +1,86 @@
+/**
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * This file is part of osm2pgsql (https://osm2pgsql.org/).
+ *
+ * Copyright (C) 2006-2022 by the osm2pgsql developer community.
+ * For a full list of authors see the git log.
+ */
+
+#include <catch.hpp>
+
+#include "common-buffer.hpp"
+
+#include "geom-from-osm.hpp"
+#include "geom-functions.hpp"
+#include "geom.hpp"
+
+TEST_CASE("geom::point_t", "[NoDB]")
+{
+    geom::point_t p;
+
+    REQUIRE(p.x() == Approx(0.0));
+    REQUIRE(p.y() == Approx(0.0));
+
+    p.set_x(1.2);
+    p.set_y(3.4);
+
+    REQUIRE(p.x() == Approx(1.2));
+    REQUIRE(p.y() == Approx(3.4));
+
+    REQUIRE(p.num_geometries() == 1);
+}
+
+TEST_CASE("geom::point_t from location", "[NoDB]")
+{
+    osmium::Location const location{3.141, 2.718};
+    geom::point_t const p{location};
+
+    REQUIRE(p.x() == Approx(3.141));
+    REQUIRE(p.y() == Approx(2.718));
+    REQUIRE(p == geom::point_t{3.141, 2.718});
+}
+
+TEST_CASE("create_point from OSM data", "[NoDB]")
+{
+    test_buffer_t buffer;
+    buffer.add_node("n10 x1.1 y2.2");
+
+    auto const geom = geom::create_point(buffer.buffer().get<osmium::Node>(0));
+
+    REQUIRE(geom.is_point());
+    REQUIRE(geometry_type(geom) == "POINT");
+    REQUIRE(num_geometries(geom) == 1);
+    REQUIRE(area(geom) == Approx(0.0));
+    REQUIRE(centroid(geom) == geom::geometry_t{geom::point_t{1.1, 2.2}});
+    REQUIRE(geom.get<geom::point_t>() == geom::point_t{1.1, 2.2});
+}
+
+TEST_CASE("geom::distance", "[NoDB]")
+{
+    geom::point_t const p1{10, 10};
+    geom::point_t const p2{20, 10};
+    geom::point_t const p3{13, 14};
+
+    REQUIRE(geom::distance(p1, p1) == Approx(0.0));
+    REQUIRE(geom::distance(p1, p2) == Approx(10.0));
+    REQUIRE(geom::distance(p1, p3) == Approx(5.0));
+}
+
+TEST_CASE("geom::interpolate", "[NoDB]")
+{
+    geom::point_t const p1{10, 10};
+    geom::point_t const p2{20, 10};
+
+    auto const i1 = geom::interpolate(p1, p1, 0.5);
+    REQUIRE(i1.x() == 10);
+    REQUIRE(i1.y() == 10);
+
+    auto const i2 = geom::interpolate(p1, p2, 0.5);
+    REQUIRE(i2.x() == 15);
+    REQUIRE(i2.y() == 10);
+
+    auto const i3 = geom::interpolate(p2, p1, 0.5);
+    REQUIRE(i3.x() == 15);
+    REQUIRE(i3.y() == 10);
+}