// Copyright (C) 2014-2015 Benjamin Kehlet

//

// This file is part of mshr.

//

// mshr is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// mshr is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with mshr. If not, see <http://www.gnu.org/licenses/>.

#include <mshr/VTPFileReader.h>

#include <dolfin/log/log.h>

#ifdef MSHR_HAS_VTK

#include <vtkXMLPolyDataReader.h>

#include <vtkPolyData.h>

#include <vtkCellArray.h>

#endif

namespace mshr

{

void VTPFileReader::read(const std::string filename,

std::vector<std::array<double, 3> >& vertices,

std::vector<std::array<std::size_t, 3> >& facets)

{

#ifdef MSHR_HAS_VTK

//get all data from the file

vtkXMLPolyDataReader* reader = vtkXMLPolyDataReader::New();

reader->SetFileName(filename.c_str());

reader->Update();

vtkPolyData* polydata = reader->GetOutput();

//get the number of points the file contains

const vtkIdType num_points = polydata->GetNumberOfPoints();

vertices.resize(num_points);

//read in all of the points

for(vtkIdType i = 0; i < num_points; i++)

polydata->GetPoint(i, vertices[i].data());

log(dolfin::TRACE, "Read %d vertices from vtp file", num_points);

const vtkIdType num_polys = polydata->GetNumberOfPolys();

facets.resize(num_polys);

vtkCellArray* TriangleCells = polydata->GetPolys();

vtkIdType npts;

vtkIdType *pts;

vtkIdType facet_counter = 0;

while(TriangleCells->GetNextCell(npts, pts))

{

dolfin_assert(npts == 3);

for (int i = 0; i < 3; i++)

(facets[facet_counter])[i] = pts[i];

facet_counter++;

}

log(dolfin::TRACE, "Read %d triangular facets from vtp file", facet_counter);

dolfin_assert(facet_counter == num_polys);

#else

dolfin::dolfin_error("VTPFileReader.cpp",

"reading VTP file",

"mshr is not built with VTK support");

#endif

}

}