From 2d1a77cd67523a00cc1ba2d528232c9aaaec76ad Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Loriot?= <sebastien.loriot@cgal.org>
Date: Tue, 13 May 2025 14:49:46 +0200
Subject: [PATCH] be more permissive and allow duplicated points

---
 .../polygon_soup_self_intersections.h         | 21 ++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/polygon_soup_self_intersections.h b/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/polygon_soup_self_intersections.h
index d9a2f779991..3c3f37cfa5c 100644
--- a/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/polygon_soup_self_intersections.h
+++ b/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/polygon_soup_self_intersections.h
@@ -19,6 +19,9 @@
 
 #include <CGAL/Polygon_mesh_processing/self_intersections.h>
 #include <CGAL/Polygon_mesh_processing/triangulate_faces.h>
+#include <CGAL/Polygon_mesh_processing/repair_polygon_soup.h>
+
+#include <boost/iterator/transform_iterator.hpp>
 
 namespace CGAL::Polygon_mesh_processing {
 
@@ -27,16 +30,28 @@ template <class ConcurrencyTag = Sequential_tag,
           class PolygonRange,
           class CGAL_NP_TEMPLATE_PARAMETERS>
 bool does_polygon_soup_self_intersect(const PointRange& points,
-                                      const PolygonRange& polygons,
+                                      PolygonRange polygons,
                                       const CGAL_NP_CLASS& np = parameters::default_values())
 {
+  //let's be a bit more permissive and allow duplicated vertices
+  auto pm = parameters::choose_parameter<typename GetPointMap<PointRange, CGAL_NP_CLASS>::const_type>(parameters::get_parameter(np, internal_np::point_map));
+  using Point_3 = typename boost::property_traits<decltype(pm)>::value_type;
+  using PointRange_const_iterator = typename PointRange::const_iterator;
+  using PointRange_value_type = typename std::iterator_traits<PointRange_const_iterator>::value_type;
+  auto to_point =[pm](const PointRange_value_type& v) { return get(pm, v); };
+
+  std::vector<Point_3> unique_points(boost::make_transform_iterator(points.begin(), to_point),
+                                     boost::make_transform_iterator(points.end(), to_point));
+
+  merge_duplicate_points_in_polygon_soup(unique_points, polygons);
+
   bool is_pure_triangles = std::all_of(polygons.begin(), polygons.end(),
                                        [](const auto&f) { return f.size() == 3; });
   if(is_pure_triangles)
   {
     // if the polygon soup is pure triangles,
     // we can use the triangle soup self-intersection function
-    return does_triangle_soup_self_intersect<ConcurrencyTag>(points, polygons, np);
+    return does_triangle_soup_self_intersect<ConcurrencyTag>(unique_points, polygons);
   }
 
   // otherwise, we need to triangulate the polygons beforehand
@@ -53,7 +68,7 @@ bool does_polygon_soup_self_intersect(const PointRange& points,
 
   if (!OK) return false;
 
-  return does_triangle_soup_self_intersect<ConcurrencyTag>(points, triangles, np);
+  return does_triangle_soup_self_intersect<ConcurrencyTag>(unique_points, triangles, np);
 }
 
 } // namespace CGAL::Polygon_mesh_processing