/*===========================================================================*\
 *                                                                           *
 *                               OpenMesh                                    *
 *        Copyright (C) 2003 by Computer Graphics Group, RWTH Aachen         *
 *                           www.openmesh.org                                *
 *                                                                           *
 *---------------------------------------------------------------------------*
 *                                                                           *
 *                                License                                    *
 *                                                                           *
 *  This library is free software; you can redistribute it and/or modify it  *
 *  under the terms of the GNU Lesser General Public License as published    *
 *  by the Free Software Foundation, version 2.1.                            *
 *                                                                           *
 *  This library 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        *
 *  Lesser General Public License for more details.                          *
 *                                                                           *
 *  You should have received a copy of the GNU Lesser General Public         *
 *  License along with this library; if not, write to the Free Software      *
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.                *
 *                                                                           *
\*===========================================================================*/


//== INCLUDES =================================================================


//STL
#include <fstream>

// OpenMesh
#include <OpenMesh/Core/System/config.h>
#include <OpenMesh/Core/System/omstream.hh>
#include <OpenMesh/Core/Geometry/VectorT.hh>
#include <OpenMesh/Core/IO/BinaryHelper.hh>
#include <OpenMesh/Core/IO/IOManager.hh>
#include <OpenMesh/Core/IO/writer/STLWriter.hh>

//=== NAMESPACES ==============================================================


namespace OpenMesh {
namespace IO {


//=== INSTANCIATE =============================================================


_STLWriter_  __STLWriterInstance;
_STLWriter_& STLWriter() { return __STLWriterInstance; }


//=== IMPLEMENTATION ==========================================================


_STLWriter_::_STLWriter_() { IOManager().register_module(this); }


//-----------------------------------------------------------------------------


bool
_STLWriter_::
write(const std::string& _filename, BaseExporter& _be, Options _opt) const
{
  // check exporter features
  if (!check(_be, _opt)) return false;


  // check writer features
  if (_opt.check(Options::VertexNormal)   ||
      _opt.check(Options::VertexTexCoord) ||
      _opt.check(Options::FaceColor))
    return false;


  // binary or ascii ?
  if (_filename.rfind(".stla") != std::string::npos)
  {
    _opt -= Options::Binary;
    return write_stla(_filename, _be, _opt);
  }
  else if (_filename.rfind(".stlb") != std::string::npos)
  {
    _opt += Options::Binary;
    return write_stlb(_filename, _be, _opt);
  }
  else if (_filename.rfind(".stl") != std::string::npos)
  {
    return (_opt.check( Options::Binary ) 
	    ? write_stlb(_filename, _be, _opt)
	    : write_stla(_filename, _be, _opt) );
  }

  return false;
}


//-----------------------------------------------------------------------------


bool
_STLWriter_::
write_stla(const std::string& _filename, BaseExporter& _be, Options /* _opt */) const
{
  omlog() << "[STLWriter] : write ascii file\n";


  // open file
  FILE* out = fopen(_filename.c_str(), "w");
  if (!out)
  {
    omerr() << "[STLWriter] : cannot open file " << _filename << std::endl;
    return false;
  }




  unsigned int i, nF(_be.n_faces()), nV;
  Vec3f  a, b, c, n;
  std::vector<VertexHandle> vhandles;
  FaceHandle fh;


  // header
  fprintf(out, "solid\n");


  // write face set
  for (i=0; i<nF; ++i)
  {
    fh = FaceHandle(i);
    nV = _be.get_vhandles(fh, vhandles);

    if (nV == 3)
    {
      a = _be.point(vhandles[0]);
      b = _be.point(vhandles[1]);
      c = _be.point(vhandles[2]);
      n = (_be.has_face_normals() ?
     _be.normal(fh) :
     ((c-b) % (a-b)).normalize());

      fprintf(out, "facet normal %f %f %f\nouter loop\n", n[0], n[1], n[2]);
      fprintf(out, "vertex %.10f %.10f %.10f\n", a[0], a[1], a[2]);
      fprintf(out, "vertex %.10f %.10f %.10f\n", b[0], b[1], b[2]);
      fprintf(out, "vertex %.10f %.10f %.10f",   c[0], c[1], c[2]);
    }
    else
      omerr() << "[STLWriter] : Warning non-triangle data!\n";

    fprintf(out, "\nendloop\nendfacet\n");
  }



  fclose(out);

  return true;
}


//-----------------------------------------------------------------------------


bool
_STLWriter_::
write_stlb(const std::string& _filename, BaseExporter& _be, Options /* _opt */) const
{
  omlog() << "[STLWriter] : write binary file\n";


  // open file
  FILE* out = fopen(_filename.c_str(), "wb");
  if (!out)
  {
    omerr() << "[STLWriter] : cannot open file " << _filename << std::endl;
    return false;
  }


  unsigned int i, nF(_be.n_faces()), nV;
  Vec3f  a, b, c, n;
  std::vector<VertexHandle> vhandles;
  FaceHandle fh;


   // write header
  const char header[80] =
    "binary stl file"
    "                                                                ";
  fwrite(header, 1, 80, out);


  // number of faces
  write_int(_be.n_faces(), out);


  // write face set
  for (i=0; i<nF; ++i)
  {
    fh = FaceHandle(i);
    nV = _be.get_vhandles(fh, vhandles);

    if (nV == 3)
    {
      a = _be.point(vhandles[0]);
      b = _be.point(vhandles[1]);
      c = _be.point(vhandles[2]);
      n = (_be.has_face_normals() ?
     _be.normal(fh) :
     ((c-b) % (a-b)).normalize());

      // face normal
      write_float(n[0], out);
      write_float(n[1], out);
      write_float(n[2], out);

      // face vertices
      write_float(a[0], out);
      write_float(a[1], out);
      write_float(a[2], out);

      write_float(b[0], out);
      write_float(b[1], out);
      write_float(b[2], out);

      write_float(c[0], out);
      write_float(c[1], out);
      write_float(c[2], out);

      // space filler
      write_short(0, out);
    }
    else
      omerr() << "[STLWriter] : Warning: Skipped non-triangle data!\n";
  }


  fclose(out);
  return true;
}


//-----------------------------------------------------------------------------


size_t
_STLWriter_::
binary_size(BaseExporter& _be, Options /* _opt */) const
{
  size_t bytes(0);
  size_t _12floats(12*sizeof(float));

  bytes += 80; // header
  bytes += 4;  // #faces


  unsigned int i, nF(_be.n_faces());
  std::vector<VertexHandle> vhandles;

  for (i=0; i<nF; ++i)
    if (_be.get_vhandles(FaceHandle(i), vhandles) == 3)
      bytes += _12floats + sizeof(short);
    else
      omerr() << "[STLWriter] : Warning: Skipped non-triangle data!\n";

  return bytes;
}


//=============================================================================
} // namespace IO
} // namespace OpenMesh
//=============================================================================
