From 8224f3cd2d4487dd51b1aebb7eb1a3bd5ef030eb Mon Sep 17 00:00:00 2001
From: Matthias Hochsteger <mhochsteger@cerbsim.com>
Date: Tue, 4 Oct 2022 12:26:02 +0200
Subject: [PATCH] New debug parameter to write mesh on error, python export

---
 libsrc/meshing/meshfunc.cpp    | 14 +++++++++++++-
 libsrc/meshing/meshtype.cpp    |  1 +
 libsrc/meshing/meshtype.hpp    |  2 ++
 libsrc/meshing/python_mesh.cpp | 18 ++++++++++++++++++
 4 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/libsrc/meshing/meshfunc.cpp b/libsrc/meshing/meshfunc.cpp
index 3e4aab21..a59f1205 100644
--- a/libsrc/meshing/meshfunc.cpp
+++ b/libsrc/meshing/meshfunc.cpp
@@ -359,6 +359,8 @@ namespace netgen
 
    if (mesh.HasOpenQuads())
    {
+      if(debugparam.write_mesh_on_error)
+        md.mesh->Save("open_quads_"+ToString(md.domain)+".vol.gz");
       PrintSysError ("mesh has still open quads");
       throw NgException ("Stop meshing since too many attempts");
       // return MESHING3_GIVEUP;
@@ -423,7 +425,11 @@ namespace netgen
 
 
          if (cntsteps > mp.maxoutersteps) 
-            throw NgException ("Stop meshing since too many attempts");
+         {
+           if(debugparam.write_mesh_on_error)
+             md.mesh->Save("meshing_error_domain_"+ToString(md.domain)+".vol.gz");
+           throw NgException ("Stop meshing since too many attempts in domain " + ToString(md.domain));
+         }
 
          PrintMessage (1, "start tetmeshing");
 
@@ -504,6 +510,8 @@ namespace netgen
         bool res = (mesh.CheckConsistentBoundary() != 0);
         if (res)
         {
+           if(debugparam.write_mesh_on_error)
+              md.mesh->Save("inconsistent_surface_domain_"+ToString(md.domain)+".vol.gz");
            PrintError ("Surface mesh not consistent");
            throw NgException ("Stop meshing since surface mesh not consistent");
         }
@@ -592,7 +600,11 @@ namespace netgen
        {
          if (mp.checkoverlappingboundary)
            if (md[i].mesh->CheckOverlappingBoundary())
+           {
+             if(debugparam.write_mesh_on_error)
+               md[i].mesh->Save("overlapping_mesh_domain_"+ToString(md[i].domain)+".vol.gz");
              throw NgException ("Stop meshing since boundary mesh is overlapping");
+           }
 
          if(md[i].mesh->GetGeometry()->GetGeomType() == Mesh::GEOM_OCC)
             FillCloseSurface( md[i] );
diff --git a/libsrc/meshing/meshtype.cpp b/libsrc/meshing/meshtype.cpp
index d49d99cd..068c1ed8 100644
--- a/libsrc/meshing/meshtype.cpp
+++ b/libsrc/meshing/meshtype.cpp
@@ -2898,6 +2898,7 @@ namespace netgen
     haltsegment = 0;
     haltsegmentp1 = 0;
     haltsegmentp2 = 0;
+    write_mesh_on_error = false;
   };
 
 
diff --git a/libsrc/meshing/meshtype.hpp b/libsrc/meshing/meshtype.hpp
index 6722bde0..28d1a71e 100644
--- a/libsrc/meshing/meshtype.hpp
+++ b/libsrc/meshing/meshtype.hpp
@@ -1415,6 +1415,8 @@ namespace netgen
     ///
     int haltfacenr;
     ///
+    bool write_mesh_on_error;
+    ///
     DebugParameters ();
   };
 
diff --git a/libsrc/meshing/python_mesh.cpp b/libsrc/meshing/python_mesh.cpp
index c79013a3..dd7b7910 100644
--- a/libsrc/meshing/python_mesh.cpp
+++ b/libsrc/meshing/python_mesh.cpp
@@ -1567,6 +1567,24 @@ project_boundaries : Optional[str] = None
                                                      return old;
                                                    }));
 
+  py::class_<DebugParameters> (m, "_DebugParameters")
+      .def_readwrite("debugoutput", &DebugParameters::debugoutput)
+      .def_readwrite("slowchecks", &DebugParameters::slowchecks)
+      .def_readwrite("haltsuccess", &DebugParameters::haltsuccess)
+      .def_readwrite("haltnosuccess", &DebugParameters::haltnosuccess)
+      .def_readwrite("haltlargequalclass", &DebugParameters::haltlargequalclass)
+      .def_readwrite("haltsegment", &DebugParameters::haltsegment)
+      .def_readwrite("haltnode", &DebugParameters::haltnode)
+      .def_readwrite("haltsegmentp1", &DebugParameters::haltsegmentp1)
+      .def_readwrite("haltsegmentp2", &DebugParameters::haltsegmentp2)
+      .def_readwrite("haltexistingline", &DebugParameters::haltexistingline)
+      .def_readwrite("haltoverlap", &DebugParameters::haltoverlap)
+      .def_readwrite("haltface", &DebugParameters::haltface)
+      .def_readwrite("haltfacenr", &DebugParameters::haltfacenr)
+      .def_readwrite("write_mesh_on_error", &DebugParameters::write_mesh_on_error)
+      ;
+
+  m.attr("debugparam") = py::cast(&debugparam);
 
   m.def("ReadCGNSFile", &ReadCGNSFile, py::arg("filename"), py::arg("base")=1, "Read mesh and solution vectors from CGNS file");
   m.def("WriteCGNSFile", &WriteCGNSFile, py::arg("mesh"), py::arg("filename"), py::arg("names"), py::arg("values"), py::arg("locations"),