// -------------------------------------------------------------------------
// @author Leonardo Florez-Valencia (florez-l@javeriana.edu.co)
// -------------------------------------------------------------------------

#ifndef __CPEXTENSIONS__ALGORITHMS__GRADIENTFUNCTIONBASE__HXX__
#define __CPEXTENSIONS__ALGORITHMS__GRADIENTFUNCTIONBASE__HXX__

// -------------------------------------------------------------------------
template< class G >
void cpExtensions::Algorithms::GradientFunctionBase< G >::
ResetBuffer( )
{
  this->m_Buffer.clear( );
}

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

// -------------------------------------------------------------------------
template< class G >
typename cpExtensions::Algorithms::GradientFunctionBase< G >::
TOutput cpExtensions::Algorithms::GradientFunctionBase< G >::
EvaluateAtIndex( const TIndex& i ) const
{
  TOutput res = TOutput( 0 );
  bool computed = false;
  if( this->m_BufferResults )
  {
    typename TBuffer::const_iterator bIt = this->m_Buffer.find( i );
    computed = ( bIt != this->m_Buffer.end( ) );
    res = ( computed )? bIt->second: res;

  } // fi

  if( !computed )
    res = this->_Evaluate( i );

  if( this->m_BufferResults )
    this->m_Buffer[ i ] = res;
  return( res );
}

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

// -------------------------------------------------------------------------
template< class G >
cpExtensions::Algorithms::GradientFunctionBase< G >::
GradientFunctionBase( )
  : Superclass( ),
    m_BufferResults( false )
{
  this->m_Buffer.clear( );
}

// -------------------------------------------------------------------------
template< class G >
cpExtensions::Algorithms::GradientFunctionBase< G >::
~GradientFunctionBase( )
{
  this->m_Buffer.clear( );
}

#endif // __CPEXTENSIONS__ALGORITHMS__GRADIENTFUNCTIONBASE__HXX__

// eof - $RCSfile$