From 4dd34a08d4cb5f475fee7a2ab38f69ce76d4c0a9 Mon Sep 17 00:00:00 2001
From: Giles Bathgate <giles.bathgate@gmail.com>
Date: Sat, 8 May 2021 17:29:59 +0100
Subject: [PATCH 1/6] Add with_marks parameter to shell_to_nef

---
 Nef_3/include/CGAL/Nef_3/shell_to_nef_3.h | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/Nef_3/include/CGAL/Nef_3/shell_to_nef_3.h b/Nef_3/include/CGAL/Nef_3/shell_to_nef_3.h
index 77f024d7fb3..2691e33cda3 100644
--- a/Nef_3/include/CGAL/Nef_3/shell_to_nef_3.h
+++ b/Nef_3/include/CGAL/Nef_3/shell_to_nef_3.h
@@ -62,9 +62,10 @@ class Shell_to_nef_3
 
  private:
   SNC_structure& S;
+  bool with_marks;
  public:
 
-  Shell_to_nef_3(SNC_structure& S_) : S(S_) {}
+  Shell_to_nef_3(SNC_structure& S_, bool m_) : S(S_), with_marks(m_) {}
 
   void visit(Vertex_const_handle ) {}
   void visit(Halfedge_const_handle ) {}
@@ -83,7 +84,7 @@ class Shell_to_nef_3
     Vertex_const_handle pv = sf->center_vertex();
     Vertex_handle nv = S.new_vertex();
     nv->point() = pv->point();
-    nv->mark() = true;
+    nv->mark() = with_marks ? pv->mark() : true;
 
     SM_decorator SM(&*nv);
     SHalfedge_around_sface_const_circulator
@@ -91,7 +92,7 @@ class Shell_to_nef_3
 
     SVertex_handle sv_0 =
       SM.new_svertex(pe->source()->point());
-    sv_0->mark() = true;
+    sv_0->mark() = with_marks ? pe->source()->mark() : true;
 #ifndef CGAL_NEF_NO_INDEXED_ITEMS
     sv_0->set_index(pe->source()->get_index());
 #endif
@@ -100,7 +101,7 @@ class Shell_to_nef_3
 
     do {
       SVertex_handle sv = SM.new_svertex(pe->source()->point());
-      sv->mark() = true;
+      sv->mark() = with_marks ? pe->source()->mark() : true;
 #ifndef CGAL_NEF_NO_INDEXED_ITEMS
       sv->set_index(pe->source()->get_index());
 #endif
@@ -108,7 +109,8 @@ class Shell_to_nef_3
       SHalfedge_handle e = SM.new_shalfedge_pair(sv_prev, sv);
       e->circle() = pe_prev->circle();
       e->twin()->circle() = pe_prev->twin()->circle();
-      e->mark() = e->twin()->mark() = true;
+      e->mark() = with_marks ? pe_prev->mark() : true;
+      e->twin()->mark() = with_marks ? pe_prev->twin()->mark() : true;
 #ifndef CGAL_NEF_NO_INDEXED_ITEMS
       e->set_index(pe_prev->get_index());
       e->twin()->set_index(pe_prev->twin()->get_index());
@@ -123,7 +125,8 @@ class Shell_to_nef_3
     e = SM.new_shalfedge_pair(sv_prev, sv_0);
     e->circle() = pe_prev->circle();
     e->twin()->circle() = pe_prev->twin()->circle();
-    e->mark() = e->twin()->mark() = true;
+    e->mark() = with_marks ? pe_prev->mark() : true;
+    e->twin()->mark() = with_marks ? pe_prev->twin()->mark() : true;
 #ifndef CGAL_NEF_NO_INDEXED_ITEMS
     e->set_index(pe_prev->get_index());
     e->twin()->set_index(pe_prev->twin()->get_index());
@@ -144,9 +147,10 @@ class Shell_to_nef_3
 template <class Nef_polyhedron>
 void shell_to_nef_3(const Nef_polyhedron& N,
                     typename Nef_polyhedron::SFace_const_handle sf,
-                    typename Nef_polyhedron::SNC_structure& S)
+                    typename Nef_polyhedron::SNC_structure& S,
+                    bool with_marks = false)
 {
-  Shell_to_nef_3<typename Nef_polyhedron::SNC_structure> s2n(S);
+  Shell_to_nef_3<typename Nef_polyhedron::SNC_structure> s2n(S,with_marks);
   N.visit_shell_objects(sf, s2n);
 }
 

From 7fc5f0eb91e2b8978a3684888ac37416fca3b227 Mon Sep 17 00:00:00 2001
From: Giles Bathgate <giles.bathgate@gmail.com>
Date: Mon, 3 Jan 2022 13:36:24 +0000
Subject: [PATCH 2/6] Rename with_marks to preserve_marks

---
 Nef_3/include/CGAL/Nef_3/shell_to_nef_3.h | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/Nef_3/include/CGAL/Nef_3/shell_to_nef_3.h b/Nef_3/include/CGAL/Nef_3/shell_to_nef_3.h
index 2691e33cda3..8afb0a2aaa8 100644
--- a/Nef_3/include/CGAL/Nef_3/shell_to_nef_3.h
+++ b/Nef_3/include/CGAL/Nef_3/shell_to_nef_3.h
@@ -62,10 +62,10 @@ class Shell_to_nef_3
 
  private:
   SNC_structure& S;
-  bool with_marks;
+  bool preserve_marks;
  public:
 
-  Shell_to_nef_3(SNC_structure& S_, bool m_) : S(S_), with_marks(m_) {}
+  Shell_to_nef_3(SNC_structure& S_, bool m_) : S(S_), preserve_marks(m_) {}
 
   void visit(Vertex_const_handle ) {}
   void visit(Halfedge_const_handle ) {}
@@ -84,7 +84,7 @@ class Shell_to_nef_3
     Vertex_const_handle pv = sf->center_vertex();
     Vertex_handle nv = S.new_vertex();
     nv->point() = pv->point();
-    nv->mark() = with_marks ? pv->mark() : true;
+    nv->mark() = preserve_marks ? pv->mark() : true;
 
     SM_decorator SM(&*nv);
     SHalfedge_around_sface_const_circulator
@@ -92,7 +92,7 @@ class Shell_to_nef_3
 
     SVertex_handle sv_0 =
       SM.new_svertex(pe->source()->point());
-    sv_0->mark() = with_marks ? pe->source()->mark() : true;
+    sv_0->mark() = preserve_marks ? pe->source()->mark() : true;
 #ifndef CGAL_NEF_NO_INDEXED_ITEMS
     sv_0->set_index(pe->source()->get_index());
 #endif
@@ -101,7 +101,7 @@ class Shell_to_nef_3
 
     do {
       SVertex_handle sv = SM.new_svertex(pe->source()->point());
-      sv->mark() = with_marks ? pe->source()->mark() : true;
+      sv->mark() = preserve_marks ? pe->source()->mark() : true;
 #ifndef CGAL_NEF_NO_INDEXED_ITEMS
       sv->set_index(pe->source()->get_index());
 #endif
@@ -109,8 +109,8 @@ class Shell_to_nef_3
       SHalfedge_handle e = SM.new_shalfedge_pair(sv_prev, sv);
       e->circle() = pe_prev->circle();
       e->twin()->circle() = pe_prev->twin()->circle();
-      e->mark() = with_marks ? pe_prev->mark() : true;
-      e->twin()->mark() = with_marks ? pe_prev->twin()->mark() : true;
+      e->mark() = preserve_marks ? pe_prev->mark() : true;
+      e->twin()->mark() = preserve_marks ? pe_prev->twin()->mark() : true;
 #ifndef CGAL_NEF_NO_INDEXED_ITEMS
       e->set_index(pe_prev->get_index());
       e->twin()->set_index(pe_prev->twin()->get_index());
@@ -125,8 +125,8 @@ class Shell_to_nef_3
     e = SM.new_shalfedge_pair(sv_prev, sv_0);
     e->circle() = pe_prev->circle();
     e->twin()->circle() = pe_prev->twin()->circle();
-    e->mark() = with_marks ? pe_prev->mark() : true;
-    e->twin()->mark() = with_marks ? pe_prev->twin()->mark() : true;
+    e->mark() = preserve_marks ? pe_prev->mark() : true;
+    e->twin()->mark() = preserve_marks ? pe_prev->twin()->mark() : true;
 #ifndef CGAL_NEF_NO_INDEXED_ITEMS
     e->set_index(pe_prev->get_index());
     e->twin()->set_index(pe_prev->twin()->get_index());
@@ -148,9 +148,9 @@ template <class Nef_polyhedron>
 void shell_to_nef_3(const Nef_polyhedron& N,
                     typename Nef_polyhedron::SFace_const_handle sf,
                     typename Nef_polyhedron::SNC_structure& S,
-                    bool with_marks = false)
+                    bool preserve_marks = false)
 {
-  Shell_to_nef_3<typename Nef_polyhedron::SNC_structure> s2n(S,with_marks);
+  Shell_to_nef_3<typename Nef_polyhedron::SNC_structure> s2n(S,preserve_marks);
   N.visit_shell_objects(sf, s2n);
 }
 

From 2d2507b3644ee9b232cfb4c3a931bb951d01ffdf Mon Sep 17 00:00:00 2001
From: Giles Bathgate <giles.bathgate@gmail.com>
Date: Mon, 3 Jan 2022 16:01:29 +0000
Subject: [PATCH 3/6] Implement append operation in Nef_polyhedron_3

---
 Nef_3/include/CGAL/Nef_3/Append_volumes.h | 42 +++++++++++++++++++++++
 Nef_3/include/CGAL/Nef_polyhedron_3.h     | 11 ++++++
 2 files changed, 53 insertions(+)
 create mode 100644 Nef_3/include/CGAL/Nef_3/Append_volumes.h

diff --git a/Nef_3/include/CGAL/Nef_3/Append_volumes.h b/Nef_3/include/CGAL/Nef_3/Append_volumes.h
new file mode 100644
index 00000000000..69a292fa7c2
--- /dev/null
+++ b/Nef_3/include/CGAL/Nef_3/Append_volumes.h
@@ -0,0 +1,42 @@
+// Copyright (c) 2022  Max-Planck-Institute Saarbruecken (Germany).
+// All rights reserved.
+//
+// This file is part of CGAL (www.cgal.org).
+//
+// $URL$
+// $Id$
+// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-Commercial
+//
+//
+
+#ifndef CGAL_NEF3_APPEND_VOLUMES_H
+#define CGAL_NEF3_APPEND_VOLUMES_H
+
+#include <CGAL/license/Nef_3.h>
+
+
+#include <CGAL/Nef_polyhedron_3.h>
+#include <CGAL/Nef_3/shell_to_nef_3.h>
+
+namespace CGAL {
+
+template<typename Nef_3>
+class Append_volumes : public Modifier_base<typename Nef_3::SNC_structure>
+{
+  typedef typename Nef_3::SNC_structure SNC_structure;
+  typedef typename Nef_3::Shell_entry_const_iterator Shell_entry_const_iterator;
+public:
+   Append_volumes (const Nef_3& n) : nef(n) {}
+
+   void operator()(SNC_structure& snc)
+   {
+     Shell_entry_const_iterator si;
+     CGAL_forall_shells_of(si,nef.volumes_begin())
+       CGAL::shell_to_nef_3(nef,si,snc);
+   }
+private:
+  const Nef_3& nef;
+};
+
+} //namespace CGAL
+#endif // CGAL_NEF3_APPEND_VOLUMES_H
diff --git a/Nef_3/include/CGAL/Nef_polyhedron_3.h b/Nef_3/include/CGAL/Nef_polyhedron_3.h
index 74bb56ba885..48c23dcc085 100644
--- a/Nef_3/include/CGAL/Nef_polyhedron_3.h
+++ b/Nef_3/include/CGAL/Nef_polyhedron_3.h
@@ -43,6 +43,7 @@
 #include <CGAL/Nef_polyhedron_S2.h>
 #include <CGAL/Modifier_base.h>
 #include <CGAL/Nef_3/Mark_bounded_volumes.h>
+#include <CGAL/Nef_3/Append_volumes.h>
 
 #include <CGAL/IO/Verbose_ostream.h>
 #include <CGAL/Nef_3/polygon_mesh_to_nef_3.h>
@@ -1441,6 +1442,16 @@ protected:
     return res;
   }
 
+  Nef_polyhedron_3<Kernel,Items, Mark>
+  append(const Nef_polyhedron_3<Kernel,Items, Mark>& N1)
+  /*{\Mop returns |\Mvar| with N1 appended }*/ {
+    CGAL_NEF_TRACEN(" append between nef3 "<<&*this<<" and "<<&N1);
+    Append_volumes<Nef_polyhedron_3> appender(N1);
+    delegate(appender,true,false);
+    mark_bounded_volumes();
+    return *this;
+  }
+
   Nef_polyhedron_3<Kernel,Items, Mark>
   difference(const Nef_polyhedron_3<Kernel,Items, Mark>& N1) const
   /*{\Mop returns |\Mvar| $-$ |N1|. }*/ {

From 9f70823aa83261079937c939d8f2b88312e436ee Mon Sep 17 00:00:00 2001
From: Giles Bathgate <giles.bathgate@gmail.com>
Date: Mon, 3 Jan 2022 16:09:52 +0000
Subject: [PATCH 4/6] Use the preserve_marks parameter in Append_volumes

---
 Nef_3/include/CGAL/Nef_3/Append_volumes.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Nef_3/include/CGAL/Nef_3/Append_volumes.h b/Nef_3/include/CGAL/Nef_3/Append_volumes.h
index 69a292fa7c2..19f609e8d50 100644
--- a/Nef_3/include/CGAL/Nef_3/Append_volumes.h
+++ b/Nef_3/include/CGAL/Nef_3/Append_volumes.h
@@ -32,7 +32,7 @@ public:
    {
      Shell_entry_const_iterator si;
      CGAL_forall_shells_of(si,nef.volumes_begin())
-       CGAL::shell_to_nef_3(nef,si,snc);
+       CGAL::shell_to_nef_3(nef,si,snc,true);
    }
 private:
   const Nef_3& nef;

From 6b1dd03935f5f574be34b7caf873f9ed46126488 Mon Sep 17 00:00:00 2001
From: Giles Bathgate <giles.bathgate@gmail.com>
Date: Mon, 7 Feb 2022 19:46:45 +0000
Subject: [PATCH 5/6] Remove need for Append_volumes within append

---
 Nef_3/include/CGAL/Nef_3/Append_volumes.h | 42 -----------------------
 Nef_3/include/CGAL/Nef_polyhedron_3.h     | 10 ++++--
 2 files changed, 7 insertions(+), 45 deletions(-)
 delete mode 100644 Nef_3/include/CGAL/Nef_3/Append_volumes.h

diff --git a/Nef_3/include/CGAL/Nef_3/Append_volumes.h b/Nef_3/include/CGAL/Nef_3/Append_volumes.h
deleted file mode 100644
index 19f609e8d50..00000000000
--- a/Nef_3/include/CGAL/Nef_3/Append_volumes.h
+++ /dev/null
@@ -1,42 +0,0 @@
-// Copyright (c) 2022  Max-Planck-Institute Saarbruecken (Germany).
-// All rights reserved.
-//
-// This file is part of CGAL (www.cgal.org).
-//
-// $URL$
-// $Id$
-// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-Commercial
-//
-//
-
-#ifndef CGAL_NEF3_APPEND_VOLUMES_H
-#define CGAL_NEF3_APPEND_VOLUMES_H
-
-#include <CGAL/license/Nef_3.h>
-
-
-#include <CGAL/Nef_polyhedron_3.h>
-#include <CGAL/Nef_3/shell_to_nef_3.h>
-
-namespace CGAL {
-
-template<typename Nef_3>
-class Append_volumes : public Modifier_base<typename Nef_3::SNC_structure>
-{
-  typedef typename Nef_3::SNC_structure SNC_structure;
-  typedef typename Nef_3::Shell_entry_const_iterator Shell_entry_const_iterator;
-public:
-   Append_volumes (const Nef_3& n) : nef(n) {}
-
-   void operator()(SNC_structure& snc)
-   {
-     Shell_entry_const_iterator si;
-     CGAL_forall_shells_of(si,nef.volumes_begin())
-       CGAL::shell_to_nef_3(nef,si,snc,true);
-   }
-private:
-  const Nef_3& nef;
-};
-
-} //namespace CGAL
-#endif // CGAL_NEF3_APPEND_VOLUMES_H
diff --git a/Nef_3/include/CGAL/Nef_polyhedron_3.h b/Nef_3/include/CGAL/Nef_polyhedron_3.h
index 48c23dcc085..bb9fe4d4844 100644
--- a/Nef_3/include/CGAL/Nef_polyhedron_3.h
+++ b/Nef_3/include/CGAL/Nef_polyhedron_3.h
@@ -43,7 +43,6 @@
 #include <CGAL/Nef_polyhedron_S2.h>
 #include <CGAL/Modifier_base.h>
 #include <CGAL/Nef_3/Mark_bounded_volumes.h>
-#include <CGAL/Nef_3/Append_volumes.h>
 
 #include <CGAL/IO/Verbose_ostream.h>
 #include <CGAL/Nef_3/polygon_mesh_to_nef_3.h>
@@ -1446,9 +1445,14 @@ protected:
   append(const Nef_polyhedron_3<Kernel,Items, Mark>& N1)
   /*{\Mop returns |\Mvar| with N1 appended }*/ {
     CGAL_NEF_TRACEN(" append between nef3 "<<&*this<<" and "<<&N1);
-    Append_volumes<Nef_polyhedron_3> appender(N1);
-    delegate(appender,true,false);
+    Shell_entry_const_iterator si;
+    CGAL_forall_shells_of(si,N1.volumes_begin())
+      CGAL::shell_to_nef_3(N1,si,snc(),true);
+    SNC_external_structure es(snc());
+    es.clear_external_structure();
+    build_external_structure();
     mark_bounded_volumes();
+
     return *this;
   }
 

From dd70f9c11b72606056b121a7e828f123dbf1708e Mon Sep 17 00:00:00 2001
From: Giles Bathgate <giles.bathgate@gmail.com>
Date: Fri, 22 Apr 2022 21:40:57 +0100
Subject: [PATCH 6/6] Implement append for Nef_3 that takes a range

---
 Nef_3/include/CGAL/Nef_polyhedron_3.h | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/Nef_3/include/CGAL/Nef_polyhedron_3.h b/Nef_3/include/CGAL/Nef_polyhedron_3.h
index bb9fe4d4844..fdb2fedae27 100644
--- a/Nef_3/include/CGAL/Nef_polyhedron_3.h
+++ b/Nef_3/include/CGAL/Nef_polyhedron_3.h
@@ -1456,6 +1456,24 @@ protected:
     return *this;
   }
 
+  template <typename Range>
+  Nef_polyhedron_3<Kernel,Items, Mark>
+  append(const Range& N)
+  /*{\Mop returns |\Mvar| with the range N appended }*/ {
+    for(typename Range::const_iterator N1=N.begin(); N1!=N.end(); ++N1) {
+      CGAL_NEF_TRACEN(" append between nef3 "<<&*this<<" and "<<&*N1);
+      Shell_entry_const_iterator si;
+      CGAL_forall_shells_of(si,N1->volumes_begin())
+        CGAL::shell_to_nef_3(*N1,si,snc(),true);
+    }
+    SNC_external_structure es(snc());
+    es.clear_external_structure();
+    build_external_structure();
+    mark_bounded_volumes();
+
+    return *this;
+  }
+
   Nef_polyhedron_3<Kernel,Items, Mark>
   difference(const Nef_polyhedron_3<Kernel,Items, Mark>& N1) const
   /*{\Mop returns |\Mvar| $-$ |N1|. }*/ {