Merge pull request #1738 from joto/geom-cleanups

Fix various small code smells in geometry code

Author: lonvia

src/geom-functions.cpp

@@ -70,13 +70,13 @@ class geometry_n_visitor
 
     void operator()(geom::collection_t const &input) const
     {
-        *m_output = input[m_n - 1];
+        *m_output = input[m_n];
     }
 
     template <typename T>
     void operator()(geom::multigeometry_t<T> const &input) const
     {
-        m_output->set<T>() = input[m_n - 1];
+        m_output->set<T>() = input[m_n];
     }
 
     template <typename T>
@@ -95,13 +95,13 @@ class geometry_n_visitor
 
 void geometry_n(geometry_t *output, geometry_t const &input, std::size_t n)
 {
-    auto const num = num_geometries(input);
-    if (n < 1 || n > num) {
+    auto const max = num_geometries(input);
+    if (n < 1 || n > max) {
         output->reset();
         return;
     }
 
-    input.visit(geometry_n_visitor{output, n});
+    input.visit(geometry_n_visitor{output, n - 1});
     output->set_srid(input.srid());
 }
 
@@ -630,17 +630,17 @@ geometry_t centroid(geometry_t const &geom)
     return output;
 }
 
-void simplify(geometry_t *output, geometry_t const &geom, double tolerance)
+void simplify(geometry_t *output, geometry_t const &input, double tolerance)
 {
-    if (!geom.is_linestring()) {
+    if (!input.is_linestring()) {
         output->reset();
         return;
     }
 
     auto &ls = output->set<linestring_t>();
-    output->set_srid(geom.srid());
+    output->set_srid(input.srid());
 
-    boost::geometry::simplify(geom.get<linestring_t>(), ls, tolerance);
+    boost::geometry::simplify(input.get<linestring_t>(), ls, tolerance);
 
     // Linestrings with less then 2 nodes are invalid. Older boost::geometry
     // versions will generate a "line" with two identical points which the
@@ -650,10 +650,10 @@ void simplify(geometry_t *output, geometry_t const &geom, double tolerance)
     }
 }
 
-geometry_t simplify(geometry_t const &geom, double tolerance)
+geometry_t simplify(geometry_t const &input, double tolerance)
 {
-    geom::geometry_t output{linestring_t{}, geom.srid()};
-    simplify(&output, geom, tolerance);
+    geom::geometry_t output{linestring_t{}, input.srid()};
+    simplify(&output, input, tolerance);
     return output;
 }
 

src/geom-functions.hpp

@@ -92,30 +92,30 @@ geometry_t geometry_n(geometry_t const &input, std::size_t n);
  * Transform a geometry in 4326 into some other projection.
  *
  * \param output Pointer to output geometry.
- * \param geom Input geometry.
+ * \param input Input geometry.
  * \param reprojection Target projection.
  *
  * \pre \code geom.srid() == 4326 \endcode
  */
-void transform(geometry_t *output, geometry_t const &geom,
+void transform(geometry_t *output, geometry_t const &input,
                reprojection const &reprojection);
 
 /**
  * Transform a geometry in 4326 into some other projection.
  *
- * \param geom Input geometry.
+ * \param input Input geometry.
  * \param reprojection Target projection.
  * \returns Reprojected geometry.
  *
  * \pre \code geom.srid() == 4326 \endcode
  */
-geometry_t transform(geometry_t const &geom, reprojection const &reprojection);
+geometry_t transform(geometry_t const &input, reprojection const &reprojection);
 
 /**
  * Returns a modified geometry having no segment longer than the given
  * max_segment_length.
  *
- * \param line The input geometry, must be a linestring or multilinestring.
+ * \param geom The input geometry, must be a linestring or multilinestring.
  * \param max_segment_length The maximum length (using Euclidean distance
  *        in the length unit of the srs of the geometry) of each resulting
  *        linestring.
@@ -171,11 +171,11 @@ geometry_t centroid(geometry_t const &geom);
  * Returns null geometry for anything but linestring geometries!
  *
  * \param output Pointer to output geometry.
- * \param geom Input geometry.
+ * \param input Input geometry.
  * \param tolerance Max distance (in units of input coordinates) of a point
  *                  to other segments to be removed.
  */
-void simplify(geometry_t *output, geometry_t const &geom, double tolerance);
+void simplify(geometry_t *output, geometry_t const &input, double tolerance);
 
 /**
  * Simplify a linestring geometry using Douglas-Peucker algorithm.
@@ -185,12 +185,12 @@ void simplify(geometry_t *output, geometry_t const &geom, double tolerance);
  *
  * Returns null geometry for anything but linestring geometries!
  *
- * \param geom Input geometry.
+ * \param input Input geometry.
  * \param tolerance Max distance (in units of input coordinates) of a point
  *                  to other segments to be removed.
  * \returns Simplified geometry.
  */
-geometry_t simplify(geometry_t const &geom, double tolerance);
+geometry_t simplify(geometry_t const &input, double tolerance);
 
 } // namespace geom
 

src/geom.hpp

@@ -237,7 +237,7 @@ class geometry_t
     constexpr geometry_t() = default;
 
     constexpr explicit geometry_t(point_t &&geom, int srid = 4326)
-    : m_geom(std::move(geom)), m_srid(srid)
+    : m_geom(geom), m_srid(srid) // geom is trivially copyable, no move needed
     {}
 
     constexpr explicit geometry_t(linestring_t &&geom, int srid = 4326)