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

  Program:   Visualization Toolkit
  Module:    vtkXMLHyperOctreeReader.h

  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.

=========================================================================*/
// .NAME vtkXMLHyperOctreeReader - Read VTK XML HyperOctree files.
// .SECTION Description
// vtkXMLHyperOctreeReader reads the VTK XML HyperOctree file
// format.  One rectilinear grid file can be read to produce one
// output.  Streaming is supported.  The standard extension for this
// reader's file format is "vto".  This reader is also used to read a
// single piece of the parallel file format.

// .SECTION See Also
// vtkXMLPHyperOctreeReader

#ifndef __vtkXMLHyperOctreeReader_h
#define __vtkXMLHyperOctreeReader_h

#include "vtkXMLDataReader.h"

class vtkHyperOctree;
class vtkHyperOctreeCursor;
class vtkIntArray;

class VTK_IO_EXPORT vtkXMLHyperOctreeReader : public vtkXMLDataReader
{
public:
  vtkTypeRevisionMacro(vtkXMLHyperOctreeReader,vtkXMLDataReader);
  void PrintSelf(ostream& os, vtkIndent indent);
  static vtkXMLHyperOctreeReader *New();
  
  // Description:
  // Get the reader's output.
  vtkHyperOctree *GetOutput();
  vtkHyperOctree *GetOutput(int idx);
  
protected:
  vtkXMLHyperOctreeReader();
  ~vtkXMLHyperOctreeReader();  

  const char* GetDataSetName();

  // Setup the output with no data available.  Used in error cases.
  void SetupEmptyOutput();

  // Declare that this reader produces HyperOctrees
  virtual int FillOutputPortInformation(int, vtkInformation*);

  //These defer to the HyperOctree output.
  vtkIdType GetNumberOfPoints();
  vtkIdType GetNumberOfCells();

  // Overriden here to do allocation.
  virtual int ReadArrayForPoints(vtkXMLDataElement* da,
                                 vtkAbstractArray* outArray);
  virtual int ReadArrayForCells(vtkXMLDataElement* da,
                                vtkAbstractArray* outArray);

  

  // The most important stuff is here.
  // Read the rest of the file and create the HyperOctree.
  void ReadXMLData();

  // Recover the structure of the HyperOctree, used by ReadXMLData.
  void ReadTopology(vtkXMLDataElement *elem);

  // Used by ReadTopology to recusively build the tree, one cell at a time.
  int BuildNextCell(vtkIntArray *, vtkHyperOctreeCursor *, int);

  //Helper for BuildNextCell
  int ArrayIndex;

private:
  vtkXMLHyperOctreeReader(const vtkXMLHyperOctreeReader&);  // Not implemented.
  void operator=(const vtkXMLHyperOctreeReader&);  // Not implemented.
};

#endif
