netgen/libsrc/stlgeom/python_stl.cpp

#ifdef NG_PYTHON

#include <../general/ngpython.hpp>
#include <stlgeom.hpp>

#ifdef WIN32
   #define DLL_HEADER   __declspec(dllexport)
#endif

using namespace netgen;
namespace netgen
{
  //extern shared_ptr<Mesh> mesh;
  extern shared_ptr<NetgenGeometry> ng_geometry;
}


DLL_HEADER void ExportSTL(py::module & m)
{
  py::class_<STLGeometry,shared_ptr<STLGeometry>, NetgenGeometry> (m,"STLGeometry")
    .def(py::init<>())
    .def(py::pickle(
                    [](STLGeometry& self)
                    {
                      auto ss = make_shared<stringstream>();
                      BinaryOutArchive archive(ss);
                      archive & self;
                      archive.FlushBuffer();
                      return py::make_tuple(py::bytes(ss->str()));
                    },
                    [](py::tuple state)
                    {
                      auto geo = make_shared<STLGeometry>();
                      auto ss = make_shared<stringstream> (py::cast<py::bytes>(state[0]));
                      BinaryInArchive archive(ss);
                      archive & (*geo);
                      return geo;
                    }))
    .def("_visualizationData", [](shared_ptr<STLGeometry> stl_geo)
         {
           std::vector<float> vertices;
           std::vector<int> trigs;
           std::vector<float> normals;
           std::vector<float> min = {std::numeric_limits<float>::max(),
                               std::numeric_limits<float>::max(),
                               std::numeric_limits<float>::max()};
           std::vector<float> max = {std::numeric_limits<float>::lowest(),
                               std::numeric_limits<float>::lowest(),
                               std::numeric_limits<float>::lowest()};
           std::vector<string> surfnames;

           surfnames.push_back("stl");
           vertices.reserve(stl_geo->GetNT()*3*3);
           trigs.reserve(stl_geo->GetNT()*4);
           normals.reserve(stl_geo->GetNT()*3*3);
           size_t ii = 0;
           for(int i = 0; i < stl_geo->GetNT(); i++)
             {
               auto& trig = stl_geo->GetTriangle(i+1);
               for(int k = 0; k < 3; k++)
                 {
                   trigs.push_back(ii++);
                   auto& pnt = stl_geo->GetPoint(trig[k]);
                   for (int l = 0; l < 3; l++)
                     {
                       float val = pnt[l];
                       vertices.push_back(val);
                       min[l] = min2(min[l], val);
                       max[l] = max2(max[l], val);
                       normals.push_back(trig.Normal()[l]);
                     }
                 }
               trigs.push_back(0);
             }
            py::gil_scoped_acquire ac;
            py::dict res;
            py::list snames;
            for(auto name : surfnames)
              snames.append(py::cast(name));
            res["vertices"] = MoveToNumpy(vertices);
            res["triangles"] = MoveToNumpy(trigs);
            res["normals"] = MoveToNumpy(normals);
            res["surfnames"] = snames;
            res["min"] = MoveToNumpy(min);
            res["max"] = MoveToNumpy(max);
            return res;
         }, py::call_guard<py::gil_scoped_release>())
    ;
  m.def("LoadSTLGeometry", FunctionPointer([] (const string & filename)
					   {
					     ifstream ist(filename);
					     return shared_ptr<STLGeometry>(STLGeometry::Load(ist));
					   }),py::call_guard<py::gil_scoped_release>());
  m.def("GenerateMesh", FunctionPointer([] (shared_ptr<STLGeometry> geo, MeshingParameters &param)
					{
					  auto mesh = make_shared<Mesh>();
					  SetGlobalMesh(mesh);
					  mesh->SetGeometry(geo);
					  ng_geometry = geo;
					  try
					    {
					      geo->GenerateMesh(mesh,param);
					    }
					  catch (NgException ex)
					    {
					      cout << "Caught NgException: " << ex.What() << endl;
					    }
					  return mesh;
					}),py::call_guard<py::gil_scoped_release>())
    ;
}

PYBIND11_MODULE(libstl, m) {
  ExportSTL(m);
}

#endif