fix(NNSearch): add more info about colocalized points

include/geode/geometry/nn_search.hpp

@@ -42,6 +42,7 @@ namespace geode
     public:
         struct ColocatedInfo
         {
+            ColocatedInfo() = default;
             [[nodiscard]] index_t nb_unique_points() const
             {
                 return unique_points.size();
@@ -52,13 +53,19 @@ namespace geode
                 return colocated_mapping.size() - nb_unique_points();
             }
 
+            std::vector< Point< dimension > > unique_points;
+            /*!
+             * This list has the size of the number of points in the tree.
+             * Each index is pointing to its old point index as given in input
+             * vector.
+             */
+            std::vector< index_t > colocated_mapping;
             /*!
              * This list has the size of the number of points in the tree.
              * Each index is pointing to its new unique point stored in the
              * unique_points vector.
              */
-            std::vector< index_t > colocated_mapping;
-            std::vector< Point< dimension > > unique_points;
+            std::vector< index_t > colocated_input_points;
         };
 
     public:

src/geode/geometry/nn_search.cpp

@@ -187,6 +187,7 @@ namespace geode
             "[NNSearch::colocated_index_mapping] Given epsilon too small, "
             "should be bigger than GLOBAL_EPSILON (i.e. ",
             GLOBAL_EPSILON, ")" );
+        typename NNSearch< dimension >::ColocatedInfo result;
         std::vector< index_t > mapping( nb_points() );
         absl::c_iota( mapping, 0 );
         async::parallel_for( async::irange( index_t{ 0 }, nb_points() ),
@@ -210,23 +211,25 @@ namespace geode
                 nb_unique_points++;
             }
         }
+        result.colocated_input_points = mapping;
         index_t nb_colocated{ 0 };
         index_t count{ 0 };
-        std::vector< Point< dimension > > unique_points( nb_unique_points );
+        result.unique_points.resize( nb_unique_points );
         for( const auto p : Range{ nb_points() } )
         {
             if( mapping[p] == p )
             {
                 mapping[p] -= nb_colocated;
-                unique_points[count++] = point( p );
+                result.unique_points[count++] = point( p );
             }
             else
             {
                 nb_colocated++;
                 mapping[p] = mapping[mapping[p]];
             }
         }
-        return { std::move( mapping ), std::move( unique_points ) };
+        result.colocated_mapping = mapping;
+        return result;
     }
 
     template class opengeode_geometry_api NNSearch< 2 >;