libigl_Martin/include/igl/internal_angles.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 "internal_angles.h"
#include "edge_lengths.h"
#include "get_seconds.h"

template <typename DerivedV, typename DerivedF, typename DerivedK>
IGL_INLINE void igl::internal_angles(
  const Eigen::PlainObjectBase<DerivedV>& V,
  const Eigen::PlainObjectBase<DerivedF>& F,
  Eigen::PlainObjectBase<DerivedK> & K)
{
  using namespace Eigen;
  using namespace std;
  // Edge lengths
  Matrix<
    typename DerivedV::Scalar,
    DerivedF::RowsAtCompileTime,
    DerivedF::ColsAtCompileTime> L;
  edge_lengths(V,F,L);

  assert(F.cols() == 3 && "F should contain triangles");
  internal_angles(L,K);
}

template <typename DerivedL, typename DerivedK>
IGL_INLINE void igl::internal_angles(
  const Eigen::PlainObjectBase<DerivedL>& L,
  Eigen::PlainObjectBase<DerivedK> & K)
{
  assert(L.cols() == 3 && "Edge-lengths should come from triangles");
  const size_t m = L.rows();
  K.resize(m,3);
  //for(int d = 0;d<3;d++)
  //{
  //  const auto & s1 = L.col(d).array();
  //  const auto & s2 = L.col((d+1)%3).array();
  //  const auto & s3 = L.col((d+2)%3).array();
  //  K.col(d) = ((s3.square() + s2.square() - s1.square())/(2.*s3*s2)).acos();
  //}
  // Minimum number of iterms per openmp thread
  #ifndef IGL_OMP_MIN_VALUE
  #  define IGL_OMP_MIN_VALUE 1000
  #endif
  #pragma omp parallel for if (m>IGL_OMP_MIN_VALUE)
  for(int f = 0;f<m;f++)
  {
    for(int d = 0;d<3;d++)
    {
      const auto & s1 = L(f,d);
      const auto & s2 = L(f,(d+1)%3);
      const auto & s3 = L(f,(d+2)%3);
      K(f,d) = acos((s3*s3 + s2*s2 - s1*s1)/(2.*s3*s2));
    }
  }
}

#ifdef IGL_STATIC_LIBRARY
// Explicit template specialization
template void igl::internal_angles<Eigen::Matrix<double, -1, -1, 0, -1, -1>, Eigen::Matrix<int, -1, -1, 0, -1, -1>, Eigen::Matrix<double, -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> >&);
template void igl::internal_angles<Eigen::Matrix<double, -1, 3, 1, -1, 3>, Eigen::Matrix<unsigned int, -1, -1, 1, -1, -1>, Eigen::Matrix<double, -1, -1, 0, -1, -1> >(Eigen::PlainObjectBase<Eigen::Matrix<double, -1, 3, 1, -1, 3> > const&, Eigen::PlainObjectBase<Eigen::Matrix<unsigned int, -1, -1, 1, -1, -1> > const&, Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> >&);
#endif