GEOSSubdivideByGrid: rename include_exterior argument, add test

Author: dbaston

capi/geos_c.h.in

@@ -1175,7 +1175,7 @@ extern GEOSGeometry GEOS_DLL *GEOSSubdivideByGrid_r(
     double xmin, double ymin,
     double xmax, double ymax,
     unsigned nx, unsigned ny,
-    int include_exterior);
+    int includeExterior);
 
 /** \see GEOSGridIntersectionFractions */
 extern int GEOS_DLL GEOSGridIntersectionFractions_r(
@@ -4040,7 +4040,7 @@ extern GEOSGeometry GEOS_DLL *GEOSClipByRect(
 * \param ymax Upper bound of grid
 * \param nx number of columns in grid
 * \param ny number of rows in grid
-* \param include_exterior whether to include portions of the
+* \param includeExterior whether to include portions of the
          input geometry that do not intersect the grid in
          the returned result.
 * \return A geometry collection whose components represent the
@@ -4055,7 +4055,7 @@ extern GEOSGeometry GEOS_DLL *GEOSSubdivideByGrid(
     double xmin, double ymin,
     double xmax, double ymax,
     unsigned nx, unsigned ny,
-    int include_exterior);
+    int includeExterior);
 
 /**
 * Determine the fraction of each cell in a rectangular grid

src/operation/grid/GridIntersection.cpp

@@ -569,7 +569,6 @@ GridIntersection::subdividePolygon(const Grid<bounded_extent>& p_grid, const Geo
     const geom::GeometryFactory& gfact = *g.getFactory();
 
     const auto cropped_grid = p_grid.shrinkToFit(p_grid.getExtent().intersection(*g.getEnvelopeInternal()), false);
-    //const auto cropped_grid = p_grid;
 
     geom::Envelope gridExtent = *g.getEnvelopeInternal();
     gridExtent.expandBy(1);
@@ -619,6 +618,8 @@ GridIntersection::subdividePolygon(const Grid<bounded_extent>& p_grid, const Geo
     if (!edge_geoms.empty()) {
         auto edge_coll = gfact.createGeometryCollection(std::move(edge_geoms));
         geoms.push_back(overlayng::CoverageUnion::geomunion(edge_coll.get()));
+        // Polygon generated here may have extra nodes that do not match adjacent polygons not processed through
+        // subdividePolygon.
     }
 
     return gfact.createGeometryCollection(std::move(geoms));

tests/unit/operation/grid/GridIntersectionTest.cpp

@@ -976,4 +976,26 @@ void object::test<52>()
     check_subdivided_polygon(*g, *subd);
 }
 
+template<>
+template<>
+void object::test<53>() {
+    set_test_name("includeExterior = true");
+
+    Envelope e(0, 10, 0, 10);
+    Grid<bounded_extent> ext(e, 1, 1);
+
+    auto g = wkt_reader_.read("POLYGON ((9.5 9.5, 11 9.5, 11 11, 9.5 11, 9.5 9.5))");
+
+    auto subd = GridIntersection::subdividePolygon(ext, *g, true);
+
+    auto inside = wkt_reader_.read("POLYGON ((9.5 9.5, 10 9.5, 10 10, 9.5 10, 9.5 9.5))");
+    auto outside = wkt_reader_.read("POLYGON ((9.5 10, 10 10, 10 9.5, 11 9.5, 11 11, 9.5 11, 9.5 10))");
+
+    ensure_equals(subd->getNumGeometries(), 2u);
+
+    // ensure_equals_geometry would fail here because the generated results have extra nodes at grid cell boundaries
+    ensure(subd->getGeometryN(0)->equals(inside.get()));
+    ensure(subd->getGeometryN(1)->equals(outside.get()));
+}
+
 }