#ifndef __CPEXTENSIONS__ALGORITHMS__GRADIENTIMAGEFUNCTIONBASE__HXX__
#define __CPEXTENSIONS__ALGORITHMS__GRADIENTIMAGEFUNCTIONBASE__HXX__

// -------------------------------------------------------------------------
template< class _TGradient, class _TMask >
void
cpExtensions::Algorithms::GradientImageFunctionBase< _TGradient, _TMask >::
Prepare( ) const
{
}

// -------------------------------------------------------------------------
template< class _TGradient, class _TMask >
typename
cpExtensions::Algorithms::GradientImageFunctionBase< _TGradient, _TMask >::
TOutput
cpExtensions::Algorithms::GradientImageFunctionBase< _TGradient, _TMask >::
Evaluate( const TPoint& p ) const
{
  TIndex i;
  this->GetInputImage( )->TransformPhysicalPointToIndex( p, i );
  return( this->EvaluateAtIndex( i ) );
}

// -------------------------------------------------------------------------
template< class _TGradient, class _TMask >
typename
cpExtensions::Algorithms::GradientImageFunctionBase< _TGradient, _TMask >::
TOutput
cpExtensions::Algorithms::GradientImageFunctionBase< _TGradient, _TMask >::
EvaluateAtIndex( const TIndex& i ) const
{
  bool eval = true;
  if( this->m_Mask.IsNotNull( ) )
    eval = ( ( unsigned long )( this->m_Mask->GetPixel( i ) ) > 0 );
  if( eval )
    return( this->_Evaluate( i ) );
  else
    return( TOutput( -1 ) );
}

// -------------------------------------------------------------------------
template< class _TGradient, class _TMask >
typename
cpExtensions::Algorithms::GradientImageFunctionBase< _TGradient, _TMask >::
TOutput
cpExtensions::Algorithms::GradientImageFunctionBase< _TGradient, _TMask >::
EvaluateAtContinuousIndex( const TContIndex& i ) const
{
  TPoint p;
  this->GetInputImage( )->TransformContinuousIndexToPhysicalPoint( i, p );
  return( this->Evaluate( p ) );
}

// -------------------------------------------------------------------------
template< class _TGradient, class _TMask >
cpExtensions::Algorithms::GradientImageFunctionBase< _TGradient, _TMask >::
GradientImageFunctionBase( )
  : Superclass( )
{
}

// -------------------------------------------------------------------------
template< class _TGradient, class _TMask >
cpExtensions::Algorithms::GradientImageFunctionBase< _TGradient, _TMask >::
~GradientImageFunctionBase( )
{
}

#endif // __CPEXTENSIONS__ALGORITHMS__GRADIENTIMAGEFUNCTIONBASE__HXX__

// eof - $RCSfile$