// This file is part of libigl, a simple c++ geometry processing library.
//
// Copyright (C) 2013 Daniele Panozzo <daniele.panozzo@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/.
#ifndef IGL_PRINCIPAL_CURVATURE_H
#define IGL_PRINCIPAL_CURVATURE_H


#include <Eigen/Geometry>
#include <Eigen/Dense>

#include "igl_inline.h"
//#include <igl/cotmatrix.h>
//#include <igl/writeOFF.h>



namespace igl
{

  // Compute the principal curvature directions and magnitude of the given triangle mesh
  //   DerivedV derived from vertex positions matrix type: i.e. MatrixXd
  //   DerivedF derived from face indices matrix type: i.e. MatrixXi
  // Inputs:
  //   V       eigen matrix #V by 3
  //   F       #F by 3 list of mesh faces (must be triangles)
  //   radius  controls the size of the neighbourhood used, 1 = average edge length
  //
  // Outputs:
  //   PD1 #V by 3 maximal curvature direction for each vertex.
  //   PD2 #V by 3 minimal curvature direction for each vertex.
  //   PV1 #V by 1 maximal curvature value for each vertex.
  //   PV2 #V by 1 minimal curvature value for each vertex.
  //
  // See also: average_onto_faces, average_onto_vertices
  //
  // This function has been developed by: Nikolas De Giorgis, Luigi Rocca and Enrico Puppo.
  // The algorithm is based on:
  // Efficient Multi-scale Curvature and Crease Estimation
  // Daniele Panozzo, Enrico Puppo, Luigi Rocca
  // GraVisMa, 2010
template <
  typename DerivedV, 
  typename DerivedF,
  typename DerivedPD1, 
  typename DerivedPD2, 
  typename DerivedPV1, 
  typename DerivedPV2>
IGL_INLINE void principal_curvature(
  const Eigen::PlainObjectBase<DerivedV>& V,
  const Eigen::PlainObjectBase<DerivedF>& F,
  Eigen::PlainObjectBase<DerivedPD1>& PD1,
  Eigen::PlainObjectBase<DerivedPD2>& PD2,
  Eigen::PlainObjectBase<DerivedPV1>& PV1,
  Eigen::PlainObjectBase<DerivedPV2>& PV2,
  unsigned radius = 5,
  bool useKring = true);
}


#ifndef IGL_STATIC_LIBRARY
#include "principal_curvature.cpp"
#endif

#endif