libigl_Martin/include/igl/per_vertex_normals.cpp

// This file is part of libigl, a simple c++ geometry processing library.
// 
// Copyright (C) 2013 Alec Jacobson <alecjacobson@gmail.com>
// 
// This Source Code Form is subject to the terms of the Mozilla Public License 
// v. 2.0. If a copy of the MPL was not distributed with this file, You can 
// obtain one at http://mozilla.org/MPL/2.0/.
#include "per_vertex_normals.h"

#include "get_seconds.h"
#include "per_face_normals.h"
#include "doublearea.h"
#include "internal_angles.h"

template <typename DerivedV, typename DerivedF>
IGL_INLINE void igl::per_vertex_normals(
  const Eigen::PlainObjectBase<DerivedV>& V,
  const Eigen::PlainObjectBase<DerivedF>& F,
  const igl::PerVertexNormalsWeightingType weighting,
  Eigen::PlainObjectBase<DerivedV> & N)
{
  Eigen::PlainObjectBase<DerivedV> PFN;
  igl::per_face_normals(V,F,PFN);
  return per_vertex_normals(V,F,weighting,PFN,N);
}

template <typename DerivedV, typename DerivedF>
IGL_INLINE void igl::per_vertex_normals(
  const Eigen::PlainObjectBase<DerivedV>& V,
  const Eigen::PlainObjectBase<DerivedF>& F,
  Eigen::PlainObjectBase<DerivedV> & N)
{
  return per_vertex_normals(V,F,PER_VERTEX_NORMALS_WEIGHTING_TYPE_DEFAULT,N);
}

template <typename DerivedV, typename DerivedF, typename DerivedFN, typename DerivedN>
IGL_INLINE void igl::per_vertex_normals(
  const Eigen::PlainObjectBase<DerivedV>& V,
  const Eigen::PlainObjectBase<DerivedF>& F,
  const igl::PerVertexNormalsWeightingType weighting,
  const Eigen::PlainObjectBase<DerivedFN>& FN,
  Eigen::PlainObjectBase<DerivedN> & N)
{
  using namespace std;
  double t_start;
  t_start = get_seconds();
  // Resize for output
  N.setZero(V.rows(),3);

  Eigen::MatrixXd W(F.rows(),3);
  switch(weighting)
  {
    case PER_VERTEX_NORMALS_WEIGHTING_TYPE_UNIFORM:
      W.setConstant(1.);
      break;
    default:
      assert(false && "Unknown weighting type");
    case PER_VERTEX_NORMALS_WEIGHTING_TYPE_DEFAULT:
    case PER_VERTEX_NORMALS_WEIGHTING_TYPE_AREA:
    {
      Eigen::VectorXd A;
      doublearea(V,F,A);
      W = A.replicate(1,3);
      break;
    }
    case PER_VERTEX_NORMALS_WEIGHTING_TYPE_ANGLE:
      internal_angles(V,F,W);
      break;
  }

  // loop over faces
  const int Frows = F.rows();
//// Minimum number of iterms per openmp thread
//#ifndef IGL_OMP_MIN_VALUE
//#  define IGL_OMP_MIN_VALUE 1000
//#endif
//#pragma omp parallel for if (Frows>IGL_OMP_MIN_VALUE)
  for(int i = 0; i < Frows;i++)
  {
    // throw normal at each corner
    for(int j = 0; j < 3;j++)
    {
      // Q: Does this need to be critical?
      // A: Yes. Different (i,j)'s could produce the same F(i,j)
//#pragma omp critical
      N.row(F(i,j)) += W(i,j)*FN.row(i);
    }
  }
  // take average via normalization
  N.rowwise().normalize();
}

template <typename DerivedV, typename DerivedF>
IGL_INLINE void igl::per_vertex_normals(
  const Eigen::PlainObjectBase<DerivedV>& V,
  const Eigen::PlainObjectBase<DerivedF>& F,
  const Eigen::PlainObjectBase<DerivedV>& FN,
  Eigen::PlainObjectBase<DerivedV> & N)
{
  return
    per_vertex_normals(V,F,PER_VERTEX_NORMALS_WEIGHTING_TYPE_DEFAULT,FN,N);
}

#ifdef IGL_STATIC_LIBRARY
// Explicit template specialization
template void igl::per_vertex_normals<Eigen::Matrix<double, -1, -1, 0, -1, -1>, Eigen::Matrix<int, -1, -1, 0, -1, -1> >(Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> > const&, Eigen::PlainObjectBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> > const&, Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> > const&, Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> >&);
template void igl::per_vertex_normals<Eigen::Matrix<double, -1, -1, 0, -1, -1>, Eigen::Matrix<int, -1, -1, 0, -1, -1> >(Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> > const&, Eigen::PlainObjectBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> > const&, Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> >&);
#endif