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

  Program:   ITK-SNAP
  Module:    $RCSfile: SNAPLevelSetDriver.txx,v $
  Language:  C++
  Date:      $Date: 2010/06/28 18:45:08 $
  Version:   $Revision: 1.6 $
  Copyright (c) 2007 Paul A. Yushkevich
  
  This file is part of ITK-SNAP 

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0.txt

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  -----

  Copyright (c) 2003 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 __SNAPLevelSetDriver_txx_
#define __SNAPLevelSetDriver_txx_

// Borland compiler is very lazy so we need to instantiate the template
//  by hand 
//#if defined(__BORLANDC__)
//#include <../../../SNAPBorlandDummyTypes.h>
//#endif

#include "SNAPLevelSetDriver.h"

#include "itkCommand.h"
#include "itkNarrowBandLevelSetImageFilter.h"
#include "itkDenseFiniteDifferenceImageFilter.h"
#include "LevelSetExtensionFilter.h"
#include "itkImageDuplicator.h"

#include "itkParallelSparseFieldLevelSetImageFilter.h"

// Disable some windows debug length messages
#if defined(_MSC_VER)
#pragma warning ( disable : 4786 )
#pragma warning ( disable : 4503 )
#endif

/**
 * THIS IS A WORKAROUND FOR A BUG THAT I FOUND IN THE PARALLEL SPARSE LEVEL SET
 * FILTER. For small seeds, the way the filter splits up the image into regions
 * for different threads, some threads end up with empty regions (no nodes). The
 * function that computes the timestep from the per-region timesteps then sets
 * the timestep to 0, and the filter stops. The work-around changes the step size
 * for empty regions to 1 and fixes the problem.
 */
template< class TInputImage, class TOutputImage >
class ParallelSparseFieldLevelSetImageFilterBugFix
    : public itk::ParallelSparseFieldLevelSetImageFilter< TInputImage, TOutputImage >
{
public:

  typedef ParallelSparseFieldLevelSetImageFilterBugFix                             Self;
  typedef itk::ParallelSparseFieldLevelSetImageFilter< TInputImage, TOutputImage > Superclass;
  typedef itk::SmartPointer< Self >                                                Pointer;
  typedef itk::SmartPointer< const Self >                                          ConstPointer;
  typedef typename Superclass::TimeStepType                                        TimeStepType;

  /** Method for creation through the object factory. */
  itkNewMacro(Self)

  /** Run-time type information (and related methods). */
  itkTypeMacro(ParallelSparseFieldLevelSetImageFilterBugFix,
               itk::ParallelSparseFieldLevelSetImageFilter)

  virtual TimeStepType ThreadedCalculateChange(itk::ThreadIdType ThreadId) override
  {
    TimeStepType ts = Superclass::ThreadedCalculateChange(ThreadId);
    if(ThreadId > 0 && this->m_Data[ThreadId].m_Count == 0)
      return 1.0;
    else
      return ts;
  }
};


// Create an inverting functor
class InvertFunctor {
public:
  unsigned char operator()(unsigned char input) { 
    return input == 0 ? 1 : 0; 
  }  
};

template<unsigned int VDimension>
SNAPLevelSetDriver<VDimension>
::SNAPLevelSetDriver(FloatImageType *level_set_image,
                     ShortImageType *speed_image,
                     const SnakeParameters &sparms,
                     VectorImageType *externalAdvection)
{
  // Create the level set function
  m_LevelSetFunction = LevelSetFunctionType::New();

  // Pass the speed image to the function
  m_LevelSetFunction->SetSpeedImage(speed_image);

  // Scale the speed function to range -1 to 1
  m_LevelSetFunction->SetSpeedScaleFactor(1.0 / 0x7fff);

  // Set the external advection if any
  if(externalAdvection)
    m_LevelSetFunction->SetAdvectionField(externalAdvection);

  // Create a copy of the level set image for reinitialization
  // TODO: this is wasteful of memory
  typedef itk::ImageDuplicator<FloatImageType> Duplicator;
  typename Duplicator::Pointer dup = Duplicator::New();
  dup->SetInputImage(level_set_image);
  dup->Update();
  m_InitializationCopyImage = dup->GetOutput();

  // Store the pointer to the evolving level set image
  m_LevelSetImage = level_set_image;

  // Pass the parameters to the level set function
  AssignParametersToPhi(sparms,true);

  // Create the filter
  DoCreateLevelSetFilter();
}

template<unsigned int VDimension>
void 
SNAPLevelSetDriver<VDimension>
::AssignParametersToPhi(const SnakeParameters &p, bool itkNotUsed(firstTime))
{
  // Set up the level set function

  // The sign of the advection term is flipped in our equation
  m_LevelSetFunction->SetAdvectionWeight(- p.GetAdvectionWeight());
  m_LevelSetFunction->SetAdvectionSpeedExponent(p.GetAdvectionSpeedExponent());

  // The curvature exponent for traditional/legacy reasons has a +1 value.
  m_LevelSetFunction->SetCurvatureSpeedExponent(p.GetCurvatureSpeedExponent()+1);  
  m_LevelSetFunction->SetCurvatureWeight(p.GetCurvatureWeight());
  
  m_LevelSetFunction->SetPropagationWeight(p.GetPropagationWeight());
  m_LevelSetFunction->SetPropagationSpeedExponent(p.GetPropagationSpeedExponent());  
  m_LevelSetFunction->SetLaplacianSmoothingWeight(p.GetLaplacianWeight());
  m_LevelSetFunction->SetLaplacianSmoothingSpeedExponent(p.GetLaplacianSpeedExponent());  
  
  // We only need to recompute the internal images if the exponents to those
  // images have changed
  m_LevelSetFunction->CalculateInternalImages();
  
  // Call the initialize method
  typename LevelSetFunctionType::RadiusType radius;
  radius.Fill(1);
  m_LevelSetFunction->Initialize(radius);

  // Set the time step
  m_LevelSetFunction->SetTimeStepFactor(
    p.GetAutomaticTimeStep() ? 1.0 : p.GetTimeStepFactor());

  // Remember the parameters
  m_Parameters = p;
}

template<unsigned int VDimension>
void
SNAPLevelSetDriver<VDimension>
::DoCreateLevelSetFilter()
{
  // In this method we have the flexibility to create a level set filter
  // of any ITK solver type.  This way, we can plug in different solvers:
  // NarrowBand, ParallelSparseField, even Dense.  
  if(m_Parameters.GetSolver() == SnakeParameters::PARALLEL_SPARSE_FIELD_SOLVER)
    {
    // Define an extension to the appropriate filter class
    typedef ParallelSparseFieldLevelSetImageFilterBugFix<
        FloatImageType, FloatImageType> LevelSetFilterType;

    typedef typename LevelSetFilterType::Pointer LevelSetFilterPointer;
    LevelSetFilterPointer filter = LevelSetFilterType::New();

    // Cast this specific filter down to the lowest common denominator that is
    // a filter
    m_LevelSetFilter = filter.GetPointer();

    // Perform the special configuration tasks on the filter
    filter->SetInput(m_InitializationCopyImage);
    filter->SetNumberOfLayers(3);
    filter->SetIsoSurfaceValue(0.0f);
    filter->SetDifferenceFunction(m_LevelSetFunction);
    }
/*
  else if(m_Parameters.GetSolver() == SnakeParameters::NARROW_BAND_SOLVER)
    {
    // Define an extension to the appropriate filter class
    typedef itk::NarrowBandLevelSetImageFilter<
      FloatImageType,SpeedAdaptorType,float,FloatImageType> LevelSetFilterType;
    typedef LevelSetExtensionFilter<LevelSetFilterType> ExtensionFilter;
    typename ExtensionFilter::Pointer filter = ExtensionFilter::New();

    // Cast this specific filter down to the lowest common denominator that is
    // a filter
    m_LevelSetFilter = filter.GetPointer();

    // Perform the special configuration tasks on the filter
    filter->SetSegmentationFunction(m_LevelSetFunction);
    filter->SetInput(m_InitializationImage);
    filter->SetNarrowBandTotalRadius(5);
    filter->SetNarrowBandInnerRadius(3);
    filter->SetFeatureImage(m_LevelSetFunction->GetSpeedImage());  
    }
*/
  else if(m_Parameters.GetSolver() == SnakeParameters::DENSE_SOLVER)
    {
    // Define an extension to the appropriate filter class
    typedef itk::DenseFiniteDifferenceImageFilter<
      FloatImageType,FloatImageType> LevelSetFilterType;
    typedef LevelSetExtensionFilter<LevelSetFilterType> ExtensionFilter;
    typename ExtensionFilter::Pointer filter = ExtensionFilter::New();
    
    // Cast this specific filter down to the lowest common denominator that is
    // a filter
    m_LevelSetFilter = filter.GetPointer();

    // Perform the special configuration tasks on the filter
    filter->SetInput(m_InitializationCopyImage);
    filter->SetDifferenceFunction(m_LevelSetFunction);
    }

  else
    {
    throw itk::ExceptionObject(__FILE__,__LINE__,"Unknown level set solver requested");
    }

  // This code is common to all filters. It causes the filter to initialize
  // the necessary memory and sets the iteration counter to 0
  m_LevelSetFilter->SetManualReinitialization(true);
  m_LevelSetFilter->SetNumberOfIterations(0);
  
  // Update the largest possible region. The slicer may be changing the 
  // requested region on this image, so it's important that we always 
  // update the entire image
  m_LevelSetFilter->UpdateLargestPossibleRegion();
}

template<unsigned int VDimension>
void
SNAPLevelSetDriver<VDimension>
::Restart()
{ 
  // Tell the filter to reinitialize next time that an update will 
  // be performed, and set the number of iterations to 0
  m_LevelSetFilter->SetStateToUninitialized();
  m_LevelSetFilter->SetNumberOfIterations(0);

  // Update the largest possible region. The slicer may be changing the 
  // requested region on this image, so it's important that we always 
  // update the entire image
  m_LevelSetFilter->UpdateLargestPossibleRegion();
}

template<unsigned int VDimension>
void 
SNAPLevelSetDriver<VDimension>
::Run(unsigned int nIterations)
{
  // Increment the number of iterations 
  unsigned int nElapsed = m_LevelSetFilter->GetElapsedIterations();
  m_LevelSetFilter->SetNumberOfIterations(nElapsed + nIterations);
  
  // Update the largest possible region. The slicer may be changing the 
  // requested region on this image, so it's important that we always 
  // update the entire image
  m_LevelSetFilter->UpdateLargestPossibleRegion();
}

template<unsigned int VDimension>
bool
SNAPLevelSetDriver<VDimension>
::IsEvolutionConverged()
{
  if(m_LevelSetFilter->GetElapsedIterations() == 0)
    return false;

  // For now, require absolute convergence
  std::cout << m_LevelSetFilter->GetRMSChange() << std::endl;
  return (m_LevelSetFilter->GetRMSChange() == 0.0);
}

template<unsigned int VDimension>
unsigned int
SNAPLevelSetDriver<VDimension>
::GetElapsedIterations() const
{
  return m_LevelSetFilter->GetElapsedIterations();
}

template<unsigned int VDimension>
void 
SNAPLevelSetDriver<VDimension>
::CleanUp()
{
  // Basically, the filter is finished, and we can finally return 
  // from running the filter.  Let's clear the level set and the 
  // function to free memory
  m_LevelSetFilter = NULL;
  m_LevelSetFunction = NULL;
}

template<unsigned int VDimension>
typename SNAPLevelSetDriver<VDimension>::FloatImageType *
SNAPLevelSetDriver<VDimension>
::GetOutput()
{
  return m_LevelSetFilter->GetOutput();
}

template<unsigned int VDimension>
void
SNAPLevelSetDriver<VDimension>
::SetSnakeParameters(const SnakeParameters &sparms)
{
  // Parameter setting can be destructive or passive.  If the solver has 
  // has changed, then it's destructive, otherwise it's passive
  bool destructive = sparms.GetSolver() != m_Parameters.GetSolver();

  // First of all, pass the parameters to the phi function, which may or
  // may not cause it to recompute it's images
  AssignParametersToPhi(sparms,false);

  // Create a new level set filter
  if(destructive)
    {
    DoCreateLevelSetFilter();
    }
}

#endif

