From 31901d0197076f45e52d5c1a8c399907b250d307 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Loriot?= <sebastien.loriot@cgal.org>
Date: Mon, 22 Sep 2025 16:53:02 +0200
Subject: [PATCH 1/2] fix the initial edge size in the 2D case

---
 Basic_viewer/include/CGAL/Qt/Basic_viewer.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Basic_viewer/include/CGAL/Qt/Basic_viewer.h b/Basic_viewer/include/CGAL/Qt/Basic_viewer.h
index b26ecdd479b..2d3eb6f5792 100644
--- a/Basic_viewer/include/CGAL/Qt/Basic_viewer.h
+++ b/Basic_viewer/include/CGAL/Qt/Basic_viewer.h
@@ -1484,8 +1484,11 @@ protected:
                           (Local_point(bbox.xmin(), bbox.ymin(), bbox.zmin()),
                            Local_point(bbox.xmax(), bbox.ymax(), bbox.zmax())));
       // std::cout<<"Length of the diagonal: "<<d<<std::endl;
+      // std::cout<<"width: "<< this->width() <<std::endl;
+      // std::cout<<"height: "<< this->height() <<std::endl;
+
       m_size_vertices=1.5*d;
-      m_size_edges=d;
+      m_size_edges=is_two_dimensional()?2.5:d;
       m_size_rays=m_size_edges;
       m_size_lines=m_size_edges;
       m_size_normals=d/3;

From ca5f64b97355d8c63efc042333214ecda77b7df3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Loriot?= <sebastien.loriot@cgal.org>
Date: Tue, 23 Sep 2025 19:53:23 +0200
Subject: [PATCH 2/2] suggestion from @gdamiand

---
 Basic_viewer/include/CGAL/Qt/Basic_viewer.h | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/Basic_viewer/include/CGAL/Qt/Basic_viewer.h b/Basic_viewer/include/CGAL/Qt/Basic_viewer.h
index 2d3eb6f5792..d7e3dcd48cc 100644
--- a/Basic_viewer/include/CGAL/Qt/Basic_viewer.h
+++ b/Basic_viewer/include/CGAL/Qt/Basic_viewer.h
@@ -1480,15 +1480,17 @@ protected:
     if(!m_scene.empty())
     {
       auto& bbox=m_scene.bounding_box();
-      double d=CGAL::sqrt(CGAL::squared_distance
-                          (Local_point(bbox.xmin(), bbox.ymin(), bbox.zmin()),
-                           Local_point(bbox.xmax(), bbox.ymax(), bbox.zmax())));
+      double d=is_two_dimensional()
+              ?2.5
+              : CGAL::sqrt(CGAL::squared_distance
+                           (Local_point(bbox.xmin(), bbox.ymin(), bbox.zmin()),
+                            Local_point(bbox.xmax(), bbox.ymax(), bbox.zmax())));
       // std::cout<<"Length of the diagonal: "<<d<<std::endl;
       // std::cout<<"width: "<< this->width() <<std::endl;
       // std::cout<<"height: "<< this->height() <<std::endl;
 
       m_size_vertices=1.5*d;
-      m_size_edges=is_two_dimensional()?2.5:d;
+      m_size_edges=d;
       m_size_rays=m_size_edges;
       m_size_lines=m_size_edges;
       m_size_normals=d/3;