From fed29a6b85ac2a973dccc96ac1eccff68f43c021 Mon Sep 17 00:00:00 2001
From: Giles Bathgate <giles.bathgate@gmail.com>
Date: Sat, 27 Feb 2021 11:58:01 +0000
Subject: [PATCH] Use SHalfedge handle instead of repeated vector lookup

---
 Nef_3/include/CGAL/Nef_3/SNC_indexed_items.h  |  9 ++++---
 .../CGAL/Nef_3/polygon_mesh_to_nef_3.h        | 26 ++++++++-----------
 2 files changed, 17 insertions(+), 18 deletions(-)

diff --git a/Nef_3/include/CGAL/Nef_3/SNC_indexed_items.h b/Nef_3/include/CGAL/Nef_3/SNC_indexed_items.h
index 786971053d3..ee16c2402bf 100644
--- a/Nef_3/include/CGAL/Nef_3/SNC_indexed_items.h
+++ b/Nef_3/include/CGAL/Nef_3/SNC_indexed_items.h
@@ -116,7 +116,8 @@ class SNC_indexed_items {
       init_ifacet = sl.init_ifacet;
       return *this;
     }
-
+    int new_index()
+    { index = Index_generator::get_unique_index(); return index; }
     void set_index(int idx = Index_generator::get_unique_index())
     { index = idx; }
     int get_index() const { return index; }
@@ -151,7 +152,8 @@ class SNC_indexed_items {
       init_ifacet = se.init_ifacet;
       return *this;
     }
-
+    int new_index()
+    { index = index2 = Index_generator::get_unique_index(); return index; }
     void set_index(int idx = Index_generator::get_unique_index())
     { index = index2 = idx; }
     int get_index() const {
@@ -186,7 +188,8 @@ class SNC_indexed_items {
       index = sv.index;
       return *this;
     }
-
+    int new_index()
+    { index = Index_generator::get_unique_index(); return index; }
     void set_index(int idx = Index_generator::get_unique_index())
     { index = idx; }
     int get_index() const { return index; }
diff --git a/Nef_3/include/CGAL/Nef_3/polygon_mesh_to_nef_3.h b/Nef_3/include/CGAL/Nef_3/polygon_mesh_to_nef_3.h
index f7d33128ad2..b639fa6d4e1 100644
--- a/Nef_3/include/CGAL/Nef_3/polygon_mesh_to_nef_3.h
+++ b/Nef_3/include/CGAL/Nef_3/polygon_mesh_to_nef_3.h
@@ -148,26 +148,22 @@ public:
     for(face_descriptor fi : faces(P)) {
       Halfedge_around_facet_const_circulator
         fc(halfedge(fi,P),P), end(fc);
-      typename boost::property_traits<HalfedgeIndexMap>::value_type
-        index = get(him,*fc);
-      hash[index]->set_index();
-      hash[index]->twin()->set_index();
-      hash[index]->twin()->source()->set_index();
-      int se  = hash[index]->get_index();
-      int set = hash[index]->twin()->get_index();
-      int sv  = hash[index]->twin()->source()->get_index();
+      SHalfedge_handle s = hash[get(him,*fc)];
+      int se  = s->new_index();
+      int set = s->twin()->new_index();
+      int sv  = s->twin()->source()->new_index();
 
       ++fc;
       CGAL_For_all(fc, end) {
-        index = get(him,*fc);
-        hash[index]->set_index(se);
-        hash[index]->twin()->set_index(set);
-        hash[index]->source()->set_index(sv);
-        hash[index]->twin()->source()->set_index();
-        sv = hash[index]->twin()->source()->get_index();
+        SHalfedge_handle n = hash[get(him,*fc)];
+        n->set_index(se);
+        n->twin()->set_index(set);
+        n->source()->set_index(sv);
+        sv = n->twin()->source()->new_index();
       }
-      hash[get(him,*fc)]->source()->set_index(sv);
+      s->source()->set_index(sv);
     }
+
   }
 };