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

  Program:   Visualization Toolkit
  Module:    vtkImageCacheFilter.cxx
  Language:  C++
  Date:      $Date$
  Version:   $Revision$

  Copyright (c) 1993-2002 Ken Martin, Will Schroeder, Bill Lorensen 
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/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 notice for more information.

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

#include "vtkImageData.h"
#include "vtkObjectFactory.h"
#include "vtkPointData.h"

vtkCxxRevisionMacro(vtkImageCacheFilter, "1.19");
vtkStandardNewMacro(vtkImageCacheFilter);

//----------------------------------------------------------------------------
vtkImageCacheFilter::vtkImageCacheFilter()
{
  this->CacheSize = 0;
  this->Data = NULL;
  this->Times = NULL;
  
  this->SetCacheSize(10);
}

//----------------------------------------------------------------------------
vtkImageCacheFilter::~vtkImageCacheFilter()
{
  this->SetCacheSize(0);
}


//----------------------------------------------------------------------------
void vtkImageCacheFilter::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os,indent);

  int idx, *ext;
  vtkIndent i2 = indent.GetNextIndent();
  
  os << indent << "CacheSize: " << this->CacheSize << endl;
  os << indent << "Caches: \n";
  for (idx = 0; idx < this->CacheSize; ++idx)
    {
    if (this->Data[idx])
      {
      ext = this->Data[idx]->GetExtent();
      os << i2 << idx << ": (" << this->Times[idx] 
         << ") " << ext[0] << ", " << ext[1] << ", " << ext[2] << ", " 
         << ext[3] << ", " << ext[4] << ", " << ext[5] << endl;
      }
    }
}

void vtkImageCacheFilter::SetCacheSize(int size)
{
  int idx;
  
  if (size == this->CacheSize)
    {
    return;
    }
  
  this->Modified();
  
  // free the old data
  for (idx = 0; idx < this->CacheSize; ++idx)
    {
    if (this->Data[idx])
      {
      this->Data[idx]->Delete();
      this->Data[idx] = NULL;
      }
    }
  if (this->Data)
    {
    delete [] this->Data;
    this->Data = NULL;
    }
  if (this->Times)
    {
    delete [] this->Times;
    this->Times = NULL;
    }
  
  this->CacheSize = size;
  if (size == 0)
    {
    return;
    }
  
  this->Data = new vtkImageData* [size];
  this->Times = new unsigned long [size];

  for (idx = 0; idx < size; ++idx)
    {
    this->Data[idx] = NULL;
    this->Times[idx] = 0;
    }
}

//----------------------------------------------------------------------------
// This method simply copies by reference the input data to the output.
void vtkImageCacheFilter::UpdateData(vtkDataObject *outObject)
{
  unsigned long pmt;
  int *uExt, *ext;
  vtkImageData *outData = (vtkImageData *)(outObject);
  vtkImageData *inData = this->GetInput();
  int i;
  int flag = 0;

  if (!inData)
    {
    vtkErrorMacro(<< "Input not set.");
    return;
    }

  uExt = outData->GetUpdateExtent();

  // First look through the cached data to see if it is still valid.
  pmt = inData->GetPipelineMTime();
  for (i = 0; i < this->CacheSize; ++i)
    {
    if (this->Data[i] && this->Times[i] < pmt)
      {
      this->Data[i]->Delete();
      this->Times[i] = 0;
      }
    }

  // Look for data that contains UpdateExtent.
  for (i = 0; i < this->CacheSize; ++i)
    {
    if (this->Data[i])
      {
      ext = this->Data[i]->GetExtent();
      if (uExt[0] >= ext[0] && uExt[1] <= ext[1] &&
          uExt[2] >= ext[2] && uExt[3] <= ext[3] &&
          uExt[4] >= ext[4] && uExt[5] <= ext[5])
        {
        vtkDebugMacro("Found Cached Data to meet request" );
        
        // Pass this data to output.
        outData->SetExtent(ext);
        outData->GetPointData()->PassData(this->Data[i]->GetPointData());
        outData->DataHasBeenGenerated();
        flag = 1;
        }
      }
    }


  if (flag == 0)
    {
    unsigned long bestTime = VTK_LARGE_INTEGER;
    int bestIdx = 0;

    // we need to update.
    inData->SetUpdateExtent(uExt);
    inData->PropagateUpdateExtent();
    inData->UpdateData();
    
    if (inData->GetDataReleased())
      { // special case  
      return;
      }

    vtkDebugMacro("Generating Data to meet request" );
    
    outData->SetExtent(inData->GetExtent());
    outData->GetPointData()->PassData(inData->GetPointData());
    outData->DataHasBeenGenerated();
    
    // Save the image in cache.
    // Find a spot to put the data.
    for (i = 0; i < this->CacheSize; ++i)
      {
      if (this->Data[i] == NULL)
        {
        bestIdx = i;
        bestTime = 0;
        break;
        }
      if (this->Times[i] < bestTime)
        {
        bestIdx = i;
        bestTime = this->Times[i];
        }
      }
    if (this->Data[bestIdx] == NULL)
      {
      this->Data[bestIdx] = vtkImageData::New();
      }
    this->Data[bestIdx]->ReleaseData();
    this->Data[bestIdx]->SetScalarType(inData->GetScalarType());
    this->Data[bestIdx]->SetExtent(inData->GetExtent());
    this->Data[bestIdx]->SetNumberOfScalarComponents(inData->GetNumberOfScalarComponents());
    this->Data[bestIdx]->GetPointData()->SetScalars(inData->GetPointData()->GetScalars());
    this->Times[bestIdx] = inData->GetUpdateTime();
    
    // release input data
    if (this->GetInput()->ShouldIReleaseData())
      {
      this->GetInput()->ReleaseData();
      }
    }
}



