Remove repeated points from multipoints

bench/vtile-encode.cpp

@@ -32,7 +32,7 @@ int main(int argc, char** argv)
     {
         if (argc < 4)
         {
-            std::clog << "usage: vtile-encode /path/to/geometry.geojson z x y [iterations]\n";
+            std::clog << "usage: vtile-encode /path/to/geometry.geojson z x y [-i iterations] [-l layer_count] [-o output_file] [-p epsg_code]\n";
             return -1;
         }
         std::string geojson_file(argv[1]);

src/vector_tile_geometry_clipper.hpp

@@ -138,6 +138,9 @@ class geometry_clipper
 
     void operator() (mapnik::geometry::multi_point<std::int64_t> & geom)
     {
+        // Here we remove repeated points from multi_point
+        auto last = std::unique(geom.begin(), geom.end());
+        geom.erase(last, geom.end());
         next_(geom);
     }
 

test/system/remove_repeated_point.cpp

@@ -0,0 +1,23 @@
+#include "catch.hpp"
+
+// test-utils
+#include "round_trip.hpp"
+#include "geom_to_wkt.hpp"
+
+// mapnik
+#include <mapnik/geometry_is_empty.hpp>
+
+TEST_CASE("vector tile multi_point encoding with repeated points should be removed")
+{
+    mapnik::geometry::multi_point<double> geom;
+    geom.emplace_back(0,0);
+    geom.emplace_back(0,0);
+    geom.emplace_back(1,1);
+    geom.emplace_back(1,1);
+    mapnik::geometry::geometry<double> new_geom = test_utils::round_trip(geom);
+    CHECK( !mapnik::geometry::is_empty(new_geom) );
+    std::string wkt;
+    CHECK( test_utils::to_wkt(wkt, new_geom) );
+    CHECK( wkt == "MULTIPOINT(128 -128,128.711 -126.578)" );
+    CHECK( new_geom.is<mapnik::geometry::multi_point<double> >() );
+}