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

  Program:   Visualization Toolkit
  Module:    vtkParticleReader.cxx

  Copyright (c) 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 "vtkParticleReader.h"

#include "vtkByteSwap.h"
#include "vtkCellArray.h"
#include "vtkFloatArray.h"
#include "vtkObjectFactory.h"
#include "vtkPointData.h"
#include "vtkPoints.h"
#include "vtkPolyData.h"

vtkCxxRevisionMacro(vtkParticleReader, "1.18");
vtkStandardNewMacro(vtkParticleReader);

// These are copied right from vtkImageReader.
// I do not know what they do.
#ifdef read
#undef read
#endif

#ifdef close
#undef close
#endif

//----------------------------------------------------------------------------
vtkParticleReader::vtkParticleReader()
{
  this->FileName = NULL;
  this->File = NULL;
  this->SwapBytes = 0;
  this->SetDataByteOrderToBigEndian();

  this->NumberOfPoints = 0;
}

//----------------------------------------------------------------------------
vtkParticleReader::~vtkParticleReader()
{ 
  if (this->File)
    {
    this->File->close();
    delete this->File;
    this->File = NULL;
    }
  
  if (this->FileName)
    {
    delete [] this->FileName;
    this->FileName = NULL;
    }
}


//----------------------------------------------------------------------------
void vtkParticleReader::OpenFile()
{
  if (!this->FileName)
    {
    vtkErrorMacro(<<"FileName must be specified.");
    return;
    }

  // Close file from any previous image
  if (this->File)
    {
    this->File->close();
    delete this->File;
    this->File = NULL;
    }
  
  // Open the new file
  vtkDebugMacro(<< "Initialize: opening file " << this->FileName);
#ifdef _WIN32
  this->File = new ifstream(this->FileName, ios::in | ios::binary);
#else
  this->File = new ifstream(this->FileName, ios::in);
#endif
  if (! this->File || this->File->fail())
    {
    vtkErrorMacro(<< "Initialize: Could not open file " << 
    this->FileName);
    return;
    }
}


//----------------------------------------------------------------------------
// This method returns the largest data that can be generated.
void vtkParticleReader::ExecuteInformation()
{
  vtkPolyData *output = this->GetOutput();

  output->SetMaximumNumberOfPieces(-1);
}


//----------------------------------------------------------------------------
// This method returns the largest data that can be generated.
void vtkParticleReader::Execute()
{
  vtkPolyData *output = this->GetOutput();
  vtkPoints *points;
  vtkFloatArray *array;
  vtkCellArray *verts;
  unsigned long fileLength, start, next, length, ptIdx, cellPtIdx;
  unsigned long cellLength;
  int piece, numPieces;
  float *data, *ptr;

  if (!this->FileName)
    {
    vtkErrorMacro(<<"FileName must be specified.");
    return;
    }
  
  this->OpenFile();
    
  // Get the size of the header from the size of the image
  this->File->seekg(0,ios::end);
  if (this->File->fail())
    {
    vtkErrorMacro("Could not seek to end of file.");
    return;
    }

  fileLength = (unsigned long)this->File->tellg();
  this->NumberOfPoints = fileLength / (4 * sizeof(float));

  piece = output->GetUpdatePiece();
  numPieces = output->GetUpdateNumberOfPieces();

  if ((unsigned long)numPieces > this->NumberOfPoints)
    {
    numPieces = (int)(this->NumberOfPoints);
    }
  if (numPieces <= 0 || piece < 0 || piece >= numPieces)
    {
    return;
    }

  start = piece * this->NumberOfPoints / numPieces;
  next = (piece+1) * this->NumberOfPoints / numPieces;

  length = next - start;

  data = new float[length * 4];

  // Seek to the first point in the file.
  this->File->seekg(start*4*sizeof(float), ios::beg);
  if (this->File->fail())
    {
    cerr << "File operation failed: Seeking to " << start*4 << endl;
    delete [] data;
    return;
    }

  // Read the data.
  this->File->read((char *)data, length*4*sizeof(float));
  if ( static_cast<unsigned long>(this->File->gcount()) != 
       static_cast<unsigned long>(length*4*sizeof(float))
     // On apple read to eof returns fail
#ifndef __APPLE_CC__     
     || this->File->fail()
#endif // __APPLE_CC__     
     )
    {
    vtkErrorMacro("Could not read points: " << start 
           << " to " << next-1);
    delete [] data;
    return;
    }
  
  // Swap bytes if necessary.
  if (this->GetSwapBytes())
    {
    vtkByteSwap::SwapVoidRange(data, length*4, sizeof(float));
    }

  ptr = data;
  points = vtkPoints::New();
  points->SetNumberOfPoints(length);
  array = vtkFloatArray::New();
  array->SetName("Count");
  verts = vtkCellArray::New();
  // Each cell will have 1000 points.  Leave a little extra space just in case.
  // We break up the cell this way so that the render will check for aborts
  // at a reasonable rate.
  verts->Allocate((int)((float)length * 1.002));
  // Keep adding cells until we run out of points.
  ptIdx = 0;
  while (length > 0)
    {
    cellLength = 1000;
    if (cellLength > length)
      {
      cellLength = length;
      }
    length = length - cellLength;
    verts->InsertNextCell((int)cellLength);
    for (cellPtIdx = 0; cellPtIdx < cellLength; ++cellPtIdx)
      {
      points->SetPoint(ptIdx, ptr[0], ptr[1], ptr[2]);
      array->InsertNextValue(ptr[3]);
      verts->InsertCellPoint(ptIdx);
      ptr += 4;
      ++ptIdx;
      }
    }
  delete [] data;
  data = ptr = NULL;

  output->SetPoints(points);
  points->Delete();
  points = NULL;
  output->SetVerts(verts);
  verts->Delete();
  verts = NULL;
  output->GetPointData()->SetScalars(array);
  array->Delete();
  array = NULL;
}


//----------------------------------------------------------------------------
void vtkParticleReader::SetDataByteOrderToBigEndian()
{
#ifndef VTK_WORDS_BIGENDIAN
  this->SwapBytesOn();
#else
  this->SwapBytesOff();
#endif
}

//----------------------------------------------------------------------------
void vtkParticleReader::SetDataByteOrderToLittleEndian()
{
#ifdef VTK_WORDS_BIGENDIAN
  this->SwapBytesOn();
#else
  this->SwapBytesOff();
#endif
}

void vtkParticleReader::SetDataByteOrder(int byteOrder)
{
  if ( byteOrder == VTK_FILE_BYTE_ORDER_BIG_ENDIAN )
    {
    this->SetDataByteOrderToBigEndian();
    }
  else
    {
    this->SetDataByteOrderToLittleEndian();
    }
}

//----------------------------------------------------------------------------
int vtkParticleReader::GetDataByteOrder()
{
#ifdef VTK_WORDS_BIGENDIAN
  if ( this->SwapBytes )
    {
    return VTK_FILE_BYTE_ORDER_LITTLE_ENDIAN;
    }
  else
    {
    return VTK_FILE_BYTE_ORDER_BIG_ENDIAN;
    }
#else
  if ( this->SwapBytes )
    {
    return VTK_FILE_BYTE_ORDER_BIG_ENDIAN;
    }
  else
    {
    return VTK_FILE_BYTE_ORDER_LITTLE_ENDIAN;
    }
#endif
}

//----------------------------------------------------------------------------
const char *vtkParticleReader::GetDataByteOrderAsString()
{
#ifdef VTK_WORDS_BIGENDIAN
  if ( this->SwapBytes )
    {
    return "LittleEndian";
    }
  else
    {
    return "BigEndian";
    }
#else
  if ( this->SwapBytes )
    {
    return "BigEndian";
    }
  else
    {
    return "LittleEndian";
    }
#endif
}


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

  // this->File, this->Colors need not be printed  
  os << indent << "FileName: " <<
    (this->FileName ? this->FileName : "(none)") << "\n";

  os << indent << "Swap Bytes: " << (this->SwapBytes ? "On\n" : "Off\n");

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

}


