Ball2D.ih

#include <cstdlib>

// IMPLEMENTATION of inline methods.

// ----------------------- Standard services ------------------------------

template <typename T>
inline
DGtal::Ball2D<T>::~Ball2D()
{
}

template <typename T>
inline
DGtal::Ball2D<T>::Ball2D(const double x0, const double y0, const double radius):
  myRadius(radius), myCenter(x0,y0) 
{}


template <typename T>
inline
DGtal::Ball2D<T>::Ball2D(const RealPoint2D &aPoint, const double radius):
  myRadius(radius), myCenter(aPoint) 
{}

template <typename T>
inline
DGtal::Ball2D<T>::Ball2D(const Point &aPoint, const double radius):
  myRadius(radius)
{
  myCenter = aPoint;
}

// ------------- Implementation of 'StarShaped' services ------------------

template <typename T>
inline
double
DGtal::Ball2D<T>::parameter( const RealPoint2D & pp ) const
{
  RealPoint2D p( pp );
  p -= myCenter;
  
  double angle = 0.0;
  if ( ( p.at( 0 ) == 0.0 ) && ( p.at( 1 ) == 0.0 ) )
    return angle;
  if ( p.at( 0 ) >= p.at( 1 ) )
    {
      if ( p.at( 0 ) >= -p.at( 1 ) )
  angle = atan( p.at( 1 ) / p.at( 0 ) );
      else
  angle = 1.5* M_PI + atan( - p.at( 0 ) / p.at( 1 ) );
    }
  else // ( p.at( 0 ) >= p.at( 1 ) )
    {
      if ( p.at( 0 ) >= -p.at( 1 ) )
  angle = 0.5*M_PI - atan( p.at( 0 ) / p.at( 1 ) );
      else
  angle = M_PI + atan( p.at( 1 ) / p.at( 0 ) );
    }
  angle = ( angle < 0.0 ) ? angle + 2*M_PI : angle;
  return angle;
}

template <typename T>
inline
typename DGtal::Ball2D<T>::RealPoint2D 
DGtal::Ball2D<T>::x( double t ) const
{
  RealPoint2D c( myRadius*cos(t), myRadius*sin(t) );
  c += myCenter;
  return c;
}


template <typename T>
inline
typename DGtal::Ball2D<T>::RealVector2D 
DGtal::Ball2D<T>::xp( const double t ) const
{
  RealVector2D c( -myRadius*sin(t), myRadius*cos(t) );
  return c;
}

template <typename T>
inline
typename DGtal::Ball2D<T>::RealVector2D
DGtal::Ball2D<T>::xpp( const double t ) const
{
  RealVector2D c( -myRadius*cos(t), -myRadius*sin(t) );
  return c;
}


// Interface - public :

template <typename T>
inline
void
DGtal::Ball2D<T>::selfDisplay ( std::ostream & out ) const
{
  out << "[Ball2D] center= "<<myCenter<<" radius="<<myRadius;
}

template <typename T>
inline
bool
DGtal::Ball2D<T>::isValid() const
{
    return true;
}



// Implementation of inline functions                                        //

template <typename T>
inline
std::ostream&
DGtal::operator<< ( std::ostream & out, 
      const Ball2D<T> & object )
{
  object.selfDisplay( out );
  return out;
}

//                                                                           //