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

  Program:   Visualization Toolkit
  Module:    vtkImageIterateFilter.cxx
  Language:  C++
  Date:      $Date$
  Version:   $Revision$
  Thanks:    Thanks to C. Charles Law who developed this class.

Copyright (c) 1993-2001 Ken Martin, Will Schroeder, Bill Lorensen 
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

 * Redistributions of source code must retain the above copyright notice,
   this list of conditions and the following disclaimer.

 * Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

 * Neither name of Ken Martin, Will Schroeder, or Bill Lorensen nor the names
   of any contributors may be used to endorse or promote products derived
   from this software without specific prior written permission.

 * Modified source versions must be plainly marked as such, and must not be
   misrepresented as being the original software.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS''
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

=========================================================================*/
#include "vtkImageIterateFilter.h"


//----------------------------------------------------------------------------
vtkImageIterateFilter::vtkImageIterateFilter()
{
  // for filters that execute multiple times
  this->Iteration = 0;
  this->NumberOfIterations = 0;
  this->IterationData = NULL;
  this->SetNumberOfIterations(1);
}

//----------------------------------------------------------------------------
vtkImageIterateFilter::~vtkImageIterateFilter()
{
  this->SetNumberOfIterations(0);
}

//----------------------------------------------------------------------------
void vtkImageIterateFilter::PrintSelf(ostream& os, vtkIndent indent)
{
  vtkImageToImageFilter::PrintSelf(os,indent);

  os << indent << "NumberOfIterations: " << this->NumberOfIterations << "\n";

  // This variable is included here to pass the PrintSelf test.
  // The variable is public to get around a compiler issue.
  // this->Iteration
}


//----------------------------------------------------------------------------
vtkImageData *vtkImageIterateFilter::GetIterationInput()
{
  if (this->IterationData == NULL || this->Iteration == 0)
    {
    // error, or return input ???
    return this->GetInput();
    }
  return this->IterationData[this->Iteration];
}


//----------------------------------------------------------------------------
vtkImageData *vtkImageIterateFilter::GetIterationOutput()
{
  if (this->IterationData == NULL || 
      this->Iteration == this->NumberOfIterations-1)
    {
    // error, or return output ???
    return this->GetOutput();
    }
  return this->IterationData[this->Iteration+1];
}

//----------------------------------------------------------------------------

void vtkImageIterateFilter::ComputeInputUpdateExtents( vtkDataObject *output )
{
  vtkImageData *in, *out = (vtkImageData*)output;
  int inExt[6], idx;

  if (!this->GetInput())
    {
    vtkErrorMacro(<< "Input not set.");
    return;
    }

  for (idx = this->NumberOfIterations - 1; idx >= 0; --idx)
    {
    this->Iteration = idx;
    in = this->GetIterationInput();
    
    if (!in)
      {
      return;
      }
    /* default value */
    out->GetUpdateExtent(inExt);
    this->ComputeInputUpdateExtent(inExt, out->GetUpdateExtent());
    in->SetUpdateExtent(inExt);
    out = in;
    }
}

//----------------------------------------------------------------------------
void vtkImageIterateFilter::AllocateOutputScalars(vtkImageData *outData)
{
  outData->SetExtent(outData->GetUpdateExtent());
  outData->AllocateScalars();
}

//----------------------------------------------------------------------------
// Some filters (decomposes, anisotropic difusion ...) have execute 
// called multiple times per update.
void vtkImageIterateFilter::ExecuteData(vtkDataObject *vtkNotUsed(out))
{
  int idx;
  vtkImageData *inData, *outData;

  // IterationData are all set up 
  // see: SetNumberOfIterations() and UpdateInformation()
  for (idx = 0; idx < this->NumberOfIterations; ++idx)
    {
    this->Iteration = idx;
    // temporarily change input and output
    inData = this->IterationData[idx];
    outData = this->IterationData[idx + 1];
    
    this->AllocateOutputScalars(outData);

    // execute for this iteration
    this->IterativeExecuteData(inData, outData);
    
    // Part of me thinks we should always release the 
    // intermediate (iteration) data.  But saving it could speed execution ...
    // Like the graphics pipeline this source releases inputs data.
    if (inData->ShouldIReleaseData())
      {
      inData->ReleaseData();
      }
    }
}


//----------------------------------------------------------------------------
// This method sets the WholeExtent, Spacing and Origin of the output.
void vtkImageIterateFilter::ExecuteInformation()
{
  vtkImageData *in, *out;
  int idx;
  
  // Make sure the Input has been set.
  if ( ! this->GetInput())
    {
    vtkErrorMacro(<< "UpdateInformation: Input is not set.");
    return;
    }

  // put the input and output into the cache list.
  // Iteration caches
  this->IterationData[0] = this->GetInput();
  this->IterationData[this->NumberOfIterations] = this->GetOutput();
  
  for (idx = 0; idx < this->NumberOfIterations; ++idx)
    {
    this->Iteration = idx;
    in = this->GetIterationInput();
    out = this->GetIterationOutput();
    
    // Set up the defaults
    out->SetWholeExtent(in->GetWholeExtent());
    out->SetSpacing(in->GetSpacing());
    out->SetOrigin(in->GetOrigin());
    out->SetScalarType(in->GetScalarType());
    out->SetNumberOfScalarComponents(in->GetNumberOfScalarComponents());

    // Let the subclass modify the default.
    this->ExecuteInformation(in, out);
    }
}

//----------------------------------------------------------------------------
//  Called by the above for each decomposition.  Subclass can modify
// the defaults by implementing this method.
void vtkImageIterateFilter::ExecuteInformation(vtkImageData *vtkNotUsed(inData),
                                       vtkImageData *vtkNotUsed(outData))
{
}


// Filters that execute multiple times per update use this internal method.
void vtkImageIterateFilter::SetNumberOfIterations(int num)
{
  int idx;
  
  if (num == this->NumberOfIterations)
    {
    return;
    }
  
  // delete previous temporary caches 
  // (first and last are global input and output)
  if (this->IterationData)
    {
    for (idx = 1; idx < this->NumberOfIterations; ++idx)
      {
      this->IterationData[idx]->UnRegister(this);
      this->IterationData[idx] = NULL;
      }
    delete [] this->IterationData;
    this->IterationData = NULL;
    }

  // special case for destructor
  if (num == 0)
    {
    return;
    }
  
  // create new ones (first and last set later to input and output)
  this->IterationData = (vtkImageData **) new void *[num + 1];
  this->IterationData[0] = this->IterationData[num] = NULL;
  for (idx = 1; idx < num; ++idx)
    {
    this->IterationData[idx] = vtkImageData::New();
    this->IterationData[idx]->ReleaseDataFlagOn();
    }

  this->NumberOfIterations = num;
  this->Modified();
}









