message: more explicit bug fix.
diff: @@ -724,13 +724,13 @@ namespace RINGMesh {
  vec3 cell_facet_barycenter( index_t cell_id, index_t facet_id ) const
  {
  vec3 result( 0., 0., 0. ) ;
  - double nb_vertices = nb_cell_facet_vertices( cell_id, facet_id ) ;
  + index_t nb_vertices = nb_cell_facet_vertices( cell_id, facet_id ) ;
  for( index_t v = 0; v < nb_vertices; ++v ) {
  result += vertex( cell_facet_vertex( cell_id, facet_id, v ) ) ;
  }
  ringmesh_assert( nb_vertices > 0 ) ;
  - return result / nb_vertices ;
  + return result / (double) nb_vertices ;
  }
  /*!
  * Compute the non weighted barycenter of the \param cell_id
  