itkQuadEdgeMeshQuadricDecimation.h

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/*=========================================================================

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkQuadEdgeMeshQuadricDecimation.h,v $
  Language:  C++
  Date:      $Date: 2010-03-24 21:51:55 $
  Version:   $Revision: 1.5 $

  Copyright (c) Insight Software Consortium. All rights reserved.
  See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notices for more information.

=========================================================================*/

#ifndef __itkQuadEdgeMeshQuadricDecimation_h
#define __itkQuadEdgeMeshQuadricDecimation_h

#include "itkQuadEdgeMeshEdgeMergeDecimationFilter.h"
#include "itkQuadEdgeMeshDecimationQuadricElementHelper.h"

namespace itk
{
template< class TInput, class TOutput, class TCriterion >
class QuadEdgeMeshQuadricDecimation :
  public QuadEdgeMeshEdgeMergeDecimationFilter< TInput, TOutput, TCriterion >
{
public:
  typedef QuadEdgeMeshQuadricDecimation               Self;
  typedef SmartPointer< Self >                        Pointer;
  typedef SmartPointer< const Self >                  ConstPointer;
  typedef QuadEdgeMeshEdgeMergeDecimationFilter< 
    TInput, TOutput, TCriterion >                     Superclass;

  itkTypeMacro( QuadEdgeMeshQuadricDecimation, QuadEdgeMeshEdgeMergeDecimationFilter );

  itkNewMacro( Self );

  typedef TInput                                      InputMeshType;
  typedef typename InputMeshType::Pointer             InputMeshPointer;

  typedef TOutput                                     OutputMeshType;
  typedef typename OutputMeshType::Pointer            OutputMeshPointer;
  typedef typename OutputMeshType::PointIdentifier    OutputPointIdentifier;
  typedef typename OutputMeshType::PointType          OutputPointType;
  typedef typename OutputPointType::CoordRepType      OutputCoordType;
  typedef typename OutputMeshType::QEType             OutputQEType;
  typedef typename OutputMeshType::EdgeCellType       OutputEdgeCellType;
  typedef typename OutputMeshType::CellsContainerIterator OutputCellsContainerIterator;
  typedef typename OutputMeshType::PointsContainerPointer OutputPointsContainerPointer;
  typedef typename OutputMeshType::PointsContainerIterator OutputPointsContainerIterator;
  
  itkStaticConstMacro( OutputPointDimension, unsigned int, OutputMeshType::PointDimension );


  typedef TCriterion                                      CriterionType;
  typedef typename CriterionType::MeasureType             MeasureType;

  typedef typename Superclass::PriorityType               PriorityType;
  typedef typename Superclass::PriorityQueueItemType      PriorityQueueItemType;
  typedef typename Superclass::PriorityQueueType          PriorityQueueType;
  typedef typename Superclass::PriorityQueuePointer       PriorityQueuePointer;

  typedef typename Superclass::QueueMapType               QueueMapType;
  typedef typename Superclass::QueueMapIterator           QueueMapIterator;

  typedef typename Superclass::OperatorType               OperatorType;
  typedef typename Superclass::OperatorPointer            OperatorPointer;

  typedef QuadEdgeMeshDecimationQuadricElementHelper< OutputPointType > 
                                                          QuadricElementType;

  typedef std::map< OutputPointIdentifier, QuadricElementType > 
                                                          QuadricElementMapType;

  typedef typename QuadricElementMapType::iterator        QuadricElementMapIterator;
      
protected:

  QuadEdgeMeshQuadricDecimation() {}
  virtual ~QuadEdgeMeshQuadricDecimation() {}
  
  QuadricElementMapType m_Quadric;

  virtual void Initialize()
    {
    OutputMeshPointer output = this->GetOutput();
    OutputPointsContainerPointer points = output->GetPoints();
    OutputPointsContainerIterator it = points->Begin();
    OutputPointIdentifier p_id;
    OutputQEType * qe;
    OutputQEType * qe_it;
    
    while( it != points->End() )
      {
      p_id = it->Index();
      
      qe = output->FindEdge( p_id );
      if( qe != 0 )
        {
        qe_it = qe;
        do
          {
          QuadricAtOrigin( qe_it, m_Quadric[p_id] );
          qe_it = qe_it->GetOnext();
          } while( qe_it != qe );
        }
      it++;
      }
    }
  
  inline void QuadricAtOrigin( OutputQEType* iEdge, QuadricElementType& oQ ) 
    {
    OutputMeshPointer output = this->GetOutput();
    
    OutputPointIdentifier id[3];
    id[0] = iEdge->GetOrigin();
    id[1] = iEdge->GetDestination();
    id[2] = iEdge->GetOnext()->GetDestination();
    
    OutputPointType p[3];
    
    for( int i = 0; i < 3; i++ )
      {
      p[i] = output->GetPoint( id[i] );
      }
    
    oQ.AddTriangle( p[0], p[1], p[2] );
    }
  
  inline MeasureType MeasureEdge( OutputQEType* iEdge )
    {
    OutputPointIdentifier id_org = iEdge->GetOrigin();
    OutputPointIdentifier id_dest = iEdge->GetDestination();
    QuadricElementType Q = m_Quadric[ id_org ] + m_Quadric[ id_dest ];

    OutputMeshPointer output = this->GetOutput();
    
    OutputPointType org = output->GetPoint( id_org );
    OutputPointType dest = output->GetPoint( id_dest );
    
    OutputPointType mid;
    mid.SetToMidPoint( org, dest );
    OutputPointType p = Q.ComputeOptimalLocation( mid );
    
    return static_cast< MeasureType >( Q.ComputeError( p ) );
    }
  
  virtual void DeletePoint( const OutputPointIdentifier& iIdToBeDeleted,
    const OutputPointIdentifier& iRemaining )
    {
    Superclass::DeletePoint( iIdToBeDeleted, iRemaining );

    QuadricElementMapIterator it = m_Quadric.find( iIdToBeDeleted );
    m_Quadric[iRemaining] += it->second;
    m_Quadric.erase( it );
    }

  OutputPointType Relocate( OutputQEType* iEdge )
    {
    OutputPointIdentifier id_org = iEdge->GetOrigin();
    OutputPointIdentifier id_dest = iEdge->GetDestination();
    QuadricElementType Q = m_Quadric[ id_org ] + m_Quadric[ id_dest ];

    OutputMeshPointer output = this->GetOutput();
    
    OutputPointType org = output->GetPoint( id_org );
    OutputPointType dest = output->GetPoint( id_dest );
    
    OutputPointType mid;
    mid.SetToMidPoint( org, dest );
    
    return Q.ComputeOptimalLocation( mid );
    }

private:
  QuadEdgeMeshQuadricDecimation( const Self& );
  void operator = ( const Self& );
};

}
#endif