From ce7761d00bb9dd0dcd611eff33f741385aa762b2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mael=20Rouxel-Labb=C3=A9?=
 <mael.rouxel.labbe@geometryfactory.com>
Date: Sat, 24 Feb 2024 00:15:49 +0100
Subject: [PATCH] Use unordered maps

---
 .../internal/dual_contouring_functors.h       | 12 +++---
 .../partition_traits_Cartesian_grid.h         | 40 +++++++++++++++++--
 2 files changed, 43 insertions(+), 9 deletions(-)

diff --git a/Isosurfacing_3/include/CGAL/Isosurfacing_3/internal/dual_contouring_functors.h b/Isosurfacing_3/include/CGAL/Isosurfacing_3/internal/dual_contouring_functors.h
index a696bfeba45..e2f35256e2a 100644
--- a/Isosurfacing_3/include/CGAL/Isosurfacing_3/internal/dual_contouring_functors.h
+++ b/Isosurfacing_3/include/CGAL/Isosurfacing_3/internal/dual_contouring_functors.h
@@ -315,8 +315,8 @@ public:
     const bool do_not_triangulate_faces =
       choose_parameter(get_parameter(np, internal_np::do_not_triangulate_faces), false);
 
-    using Edge_to_point_ID_map = std::map<Edge_descriptor, std::size_t>;
-    using Cell_to_point_ID_map = std::map<Cell_descriptor, std::size_t>;
+    using Edge_to_point_ID_map = std::unordered_map<Edge_descriptor, std::size_t>;
+    using Cell_to_point_ID_map = std::unordered_map<Cell_descriptor, std::size_t>;
 
     Edge_to_point_ID_map edge_to_point_id;
     Cell_to_point_ID_map cell_to_point_id;
@@ -446,8 +446,8 @@ public:
     bool do_not_triangulate_faces =
       choose_parameter(get_parameter(np, internal_np::do_not_triangulate_faces), false);
 
-    using Edge_to_point_ID_map = std::map<Edge_descriptor, std::size_t>;
-    using Cell_to_point_ID_map = std::map<Cell_descriptor, std::size_t>;
+    using Edge_to_point_ID_map = std::unordered_map<Edge_descriptor, std::size_t>;
+    using Cell_to_point_ID_map = std::unordered_map<Cell_descriptor, std::size_t>;
 
     Edge_to_point_ID_map edge_to_point_id;
     Cell_to_point_ID_map cell_to_point_id;
@@ -560,8 +560,8 @@ public:
     bool do_not_triangulate_faces =
       choose_parameter(get_parameter(np, internal_np::do_not_triangulate_faces), false);
 
-    using Edge_to_point_ID_map = std::map<Edge_descriptor, std::size_t>;
-    using Cell_to_point_ID_map = std::map<Cell_descriptor, std::size_t>;
+    using Edge_to_point_ID_map = std::unordered_map<Edge_descriptor, std::size_t>;
+    using Cell_to_point_ID_map = std::unordered_map<Cell_descriptor, std::size_t>;
 
     Edge_to_point_ID_map edge_to_point_id;
     Cell_to_point_ID_map cell_to_point_id;
diff --git a/Isosurfacing_3/include/CGAL/Isosurfacing_3/internal/partition_traits_Cartesian_grid.h b/Isosurfacing_3/include/CGAL/Isosurfacing_3/internal/partition_traits_Cartesian_grid.h
index 8786c8c6cb6..94d18dfbcfd 100644
--- a/Isosurfacing_3/include/CGAL/Isosurfacing_3/internal/partition_traits_Cartesian_grid.h
+++ b/Isosurfacing_3/include/CGAL/Isosurfacing_3/internal/partition_traits_Cartesian_grid.h
@@ -37,19 +37,22 @@ class Cartesian_grid_3;
 template <typename Partition>
 struct partition_traits;
 
+struct CG_Edge_descriptor : public std::array<std::size_t, 4> { };
+struct CG_Cell_descriptor : public std::array<std::size_t, 3> { };
+
 template <typename GeomTraits, typename MemoryPolicy>
 struct partition_traits<Cartesian_grid_3<GeomTraits, MemoryPolicy> >
 {
-  using Self = Cartesian_grid_3<GeomTraits, MemoryPolicy>;
+  using Grid = Cartesian_grid_3<GeomTraits, MemoryPolicy>;
 
   // identifies a vertex by its (i, j, k) indices
   using Vertex_descriptor = std::array<std::size_t, 3>;
 
   // identifies an edge by its starting vertex (i, j, k) and the direction x -> 0, y -> 1, z -> 2
-  using Edge_descriptor = std::array<std::size_t, 4>;
+  using Edge_descriptor = CG_Edge_descriptor;
 
   // identifies a cell by its corner vertex with the smallest (i, j, k) index
-  using Cell_descriptor = std::array<std::size_t, 3>;
+  using Cell_descriptor = CG_Cell_descriptor;
 
   static constexpr Cell_type CELL_TYPE = CUBICAL_CELL;
   static constexpr std::size_t VERTICES_PER_CELL = 8;
@@ -259,4 +262,35 @@ struct partition_traits<Cartesian_grid_3<GeomTraits, MemoryPolicy> >
 } // namespace Isosurfacing
 } // namespace CGAL
 
+namespace std {
+
+template <>
+struct hash<CGAL::Isosurfacing::CG_Edge_descriptor>
+{
+  std::size_t operator()(const CGAL::Isosurfacing::CG_Edge_descriptor& e) const
+  {
+    std::size_t seed = 0;
+    boost::hash_combine(seed, e[0]);
+    boost::hash_combine(seed, e[1]);
+    boost::hash_combine(seed, e[2]);
+    boost::hash_combine(seed, e[3]);
+    return seed;
+  }
+};
+
+template <>
+struct hash<CGAL::Isosurfacing::CG_Cell_descriptor>
+{
+  std::size_t operator()(const CGAL::Isosurfacing::CG_Cell_descriptor& e) const
+  {
+    std::size_t seed = 0;
+    boost::hash_combine(seed, e[0]);
+    boost::hash_combine(seed, e[1]);
+    boost::hash_combine(seed, e[2]);
+    return seed;
+  }
+};
+
+} // namespace std
+
 #endif // CGAL_ISOSURFACING_3_INTERNAL_PARTITION_TRAITS_CARTESIAN_GRID_3_H