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/*===========================================================================*\
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 *   $Revision$                                                         *
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\*===========================================================================*/




//=============================================================================
//
//  CLASS NormalConeT - IMPLEMENTATION
//
//=============================================================================

#define OPENMESH_NORMALCONE_C

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

#include <math.h>
#include "NormalConeT.hh"

#ifdef max
#  undef max
#endif

#ifdef min
#  undef min
#endif


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


namespace OpenMesh {


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

template <typename Scalar>
NormalConeT<Scalar>::
NormalConeT(const Vec3& _center_normal, Scalar _angle)
  : center_normal_(_center_normal), angle_(_angle)
{
}


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


template <typename Scalar>
Scalar 
NormalConeT<Scalar>::
max_angle(const Vec3& _norm) const
{
  Scalar dotp = (center_normal_ | _norm);
  return (dotp >= 1.0 ? 0.0 : (dotp <= -1.0 ? M_PI : acos(dotp)))
    + angle_;
}


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


template <typename Scalar>
Scalar 
NormalConeT<Scalar>::
max_angle(const NormalConeT& _cone) const
{
  Scalar dotp = (center_normal_ | _cone.center_normal_);
  Scalar centerAngle = dotp >= 1.0 ? 0.0 : (dotp <= -1.0 ? M_PI : acos(dotp));
  Scalar sideAngle0 = std::max(angle_-centerAngle, _cone.angle_);
  Scalar sideAngle1 = std::max(_cone.angle_-centerAngle, angle_);

  return centerAngle + sideAngle0 + sideAngle1;
}


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


template <typename Scalar>
void 
NormalConeT<Scalar>::
merge(const NormalConeT& _cone)
{
  Scalar dotp = (center_normal_ | _cone.center_normal_);

  if (fabs(dotp) < 0.99999f)
  {
    // new angle
    Scalar centerAngle = acos(dotp);
    Scalar minAngle    = std::min(-angle(), centerAngle - _cone.angle());
    Scalar maxAngle    = std::max( angle(), centerAngle + _cone.angle());
    angle_     = (maxAngle - minAngle) * Scalar(0.5f);

    // axis by SLERP
    Scalar axisAngle =  Scalar(0.5f) * (minAngle + maxAngle);
    center_normal_ = ((center_normal_ * sin(centerAngle-axisAngle)
		                   + _cone.center_normal_ * sin(axisAngle))
		                    / sin(centerAngle));
  }
  else
  {
    // axes point in same direction
    if (dotp > 0.0f)
      angle_ = std::max(angle_, _cone.angle_);

    // axes point in opposite directions
    else
      angle_ =  Scalar(2.0f * M_PI);
  }
}


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