From fa0a8a2bedbbb28c85b0bc671d28dbcd3cd644e7 Mon Sep 17 00:00:00 2001
From: Andreas Fabri <andreas.fabri@geometryfactory.com>
Date: Mon, 7 Mar 2022 11:59:06 +0000
Subject: [PATCH] Triangulation_2: Add an example that stars a conflict zone

---
 .../CGAL/Delaunay_triangulation_2.h           |  6 ++---
 .../Triangulation_2/star_conflict_zone.cpp    | 25 +++++++++++--------
 2 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/Triangulation_2/doc/Triangulation_2/CGAL/Delaunay_triangulation_2.h b/Triangulation_2/doc/Triangulation_2/CGAL/Delaunay_triangulation_2.h
index 911caf7983c..45a4fe12c20 100644
--- a/Triangulation_2/doc/Triangulation_2/CGAL/Delaunay_triangulation_2.h
+++ b/Triangulation_2/doc/Triangulation_2/CGAL/Delaunay_triangulation_2.h
@@ -236,7 +236,7 @@ std::pair<OutputItFaces,OutputItBoundaryEdges>
 get_conflicts_and_boundary(const Point &p,
 OutputItFaces fit,
 OutputItBoundaryEdges eit,
-Face_handle start) const;
+Face_handle start = Face_handle()) const;
 
 /*!
 outputs the faces of the conflict zone of point `p` into an output iterator.
@@ -248,7 +248,7 @@ template <class OutputItFaces>
 OutputItFaces
 get_conflicts (const Point &p,
 OutputItFaces fit,
-Face_handle start) const;
+Face_handle start = Face_handle()) const;
 
 /*!
 outputs the boundary edges of the conflict zone of point `p` into an output iterator.
@@ -266,7 +266,7 @@ template <class OutputItBoundaryEdges>
 OutputItBoundaryEdges
 get_boundary_of_conflicts(const Point &p,
 OutputItBoundaryEdges eit,
-Face_handle start) const;
+Face_handle start = Face_handle()) const;
 
 /// @}
 
diff --git a/Triangulation_2/examples/Triangulation_2/star_conflict_zone.cpp b/Triangulation_2/examples/Triangulation_2/star_conflict_zone.cpp
index bb42398e09c..2093d144e7b 100644
--- a/Triangulation_2/examples/Triangulation_2/star_conflict_zone.cpp
+++ b/Triangulation_2/examples/Triangulation_2/star_conflict_zone.cpp
@@ -22,7 +22,7 @@ int main( )
   dt2.insert(Point_2(10,0));
   dt2.insert(Point_2(0,10));
 
-  std::array<Point_2,3> points = { Point_2(2,2), Point_2(1,0), Point_2(9,9) };
+  std::array<Point_2,3> points = { Point_2(2,2), Point_2(1,0), Point_2(2,2) };
 
   CGAL::spatial_sort(points.begin(), points.end());
 
@@ -40,19 +40,22 @@ int main( )
                                    std::back_inserter(edges),
                                    hint);
 
-    // Do something with the faces before the insertion
+    if(faces.empty()){
+      std::cout << "point " << p << " already in the triangulation" << std::endl;
+    }else{
+      // Do something with the faces before the insertion
 
-    Vertex_handle vh = dt2.star_hole(p,
-                                     edges.begin(), edges.end(),
-                                     faces.begin(), faces.end());
-    hint = vh->face(); // we could also take any element of faces
+      Vertex_handle vh = dt2.star_hole(p,
+                                       edges.begin(), edges.end(),
+                                       faces.begin(), faces.end());
+      hint = vh->face(); // we could also take any element of faces
 
-    // Do something with the faces after the insertion
-    Face_circulator fc = dt2.incident_faces(vh), done(fc);
-    do {
+      // Do something with the faces after the insertion
+      Face_circulator fc = dt2.incident_faces(vh), done(fc);
+      do {
         fc++;
-    } while (fc != done);
-
+      } while (fc != done);
+    }
     draw(dt2);
   }
   return 0;