normal_cycle.h

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/* SPDX-FileCopyrightText: 2000 `Bruno Levy <levy@loria.fr>`
 * SPDX-FileCopyrightText: 2023 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 *
 * The Original Code is:
 * - OGF/Graphite: Geometry and Graphics Programming Library + Utilities.
 */
 
#pragma once

 
#include "Geom.h"
 
#include "../system/FreestyleConfig.h"
 
#include "MEM_guardedalloc.h"
 
namespace Freestyle {
 
using namespace Geometry;
 
namespace OGF {
 
template<class T> inline void ogf_swap(T &x, T &y)
{
  T z = x;
  x = y;
  y = z;
}
 
//_________________________________________________________

class NormalCycle {
 public:
  void begin();
  void end();
  void accumulate_dihedral_angle(const Vec3r &edge, real angle, real neigh_area = 1.0);
 
  const Vec3r &eigen_vector(int i) const
  {
    return axis_[i_[i]];
  }
 
  real eigen_value(int i) const
  {
    return eigen_value_[i_[i]];
  }
 
  const Vec3r &N() const
  {
    return eigen_vector(2);
  }
 
  const Vec3r &Kmax() const
  {
    return eigen_vector(1);
  }
 
  const Vec3r &Kmin() const
  {
    return eigen_vector(0);
  }
 
  real n() const
  {
    return eigen_value(2);
  }
 
  real kmax() const
  {
    return eigen_value(1);
  }
 
  real kmin() const
  {
    return eigen_value(0);
  }
 
 private:
  /* UNUSED */
  // real center_[3];
  Vec3r axis_[3];
  real eigen_value_[3];
  real M_[6];
  int i_[3];
 
  MEM_CXX_CLASS_ALLOC_FUNCS("Freestyle:OGF:NormalCycle")
};
 
inline void NormalCycle::accumulate_dihedral_angle(const Vec3r &edge,
                                                   const double beta,
                                                   double neigh_area)
{
  double s = beta * neigh_area / edge.norm();
 
  M_[0] += s * edge.x() * edge.x();
  M_[1] += s * edge.x() * edge.y();
  M_[2] += s * edge.y() * edge.y();
  M_[3] += s * edge.x() * edge.z();
  M_[4] += s * edge.y() * edge.z();
  M_[5] += s * edge.z() * edge.z();
}
 
//_________________________________________________________
 
}  // namespace OGF
 
} /* namespace Freestyle */