merge preprocessing and corefinement examples

Constrained_triangulation_3/doc/Constrained_triangulation_3/examples.txt

@@ -31,20 +31,13 @@ How to use `CGAL::tetrahedral_isotropic_remeshing` with a constrained Delaunay t
 From a non-manifold OFF file, construct the constrained Delaunay triangulation.
 */
 
-/*!
-\example Constrained_triangulation_3/ccdt_3_after_autorefinement.cpp
-@brief
-
-From a self-intersecting triangulated surface in an OFF file, construct the constrained Delaunay triangulation
-after autorefinement.
-*/
 
 /*!
 \example Constrained_triangulation_3/ccdt_3_preprocessing.cpp
 @brief
 
-From a self-intersecting and non-triangulated surface surface in an OFF file,
-construct the constrained Delaunay triangulation after preprocessing.
+From a self-intersecting and non-triangulated surface in an OFF file,
+construct the constrained Delaunay triangulation after preprocessing by autorefinement.
 */
 
 /*!

Constrained_triangulation_3/examples/Constrained_triangulation_3/ccdt_3_preprocessing.cpp

@@ -65,6 +65,12 @@ int main(int argc, char* argv[])
     std::cout << "Number of facets after preprocessing: "
               << polygons.size() << "\n";
 
+    if(PMP::does_polygon_soup_self_intersect(points, polygons))
+    {
+      std::cerr << "Error: mesh still self-intersects after autorefine\n";
+      return EXIT_FAILURE;
+    }
+
     ccdt = CGAL::make_conforming_constrained_Delaunay_triangulation_3(points, polygons);
 
   }