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

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkMeshSource.h,v $
  Language:  C++
  Date:      $Date: 2005/12/01 11:17:00 $
  Version:   $Revision: 1.25 $

  Copyright (c) Insight Software Consortium. All rights reserved.
  See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.

  Portions of this code are covered under the VTK copyright.
  See VTKCopyright.txt or http://www.kitware.com/VTKCopyright.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 __itkMeshSource_h
#define __itkMeshSource_h

#if defined(_MSC_VER)
#pragma warning ( disable : 4786 )
#endif
#include "itkProcessObject.h"

namespace itk
{

/** \class MeshSource
 *  \brief Base class for all process objects that output mesh data.
 *
 * MeshSource is the base class for all process objects that output
 * mesh data. Specifically, this class defines the GetOutput() method
 * that returns a pointer to the output mesh. The class also defines
 * some internal private data members that are used to manage streaming
 * of data.
 *
 * \ingroup DataSources
 */
template <class TOutputMesh>
class ITK_EXPORT MeshSource : public ProcessObject
{
public:
  /** Standard class typedefs. */
  typedef MeshSource         Self;
  typedef ProcessObject  Superclass;
  typedef SmartPointer<Self>  Pointer;
  typedef SmartPointer<const Self>  ConstPointer;
  
  /** Method for creation through the object factory. */
  itkNewMacro(Self);  

  /** Run-time type information (and related methods). */
  itkTypeMacro(MeshSource,ProcessObject);

  /** Some convenient typedefs. */
  typedef DataObject::Pointer DataObjectPointer;
  typedef TOutputMesh OutputMeshType;
  typedef typename OutputMeshType::Pointer OutputMeshPointer;
  
  /** Get the mesh output of this process object.  */
  OutputMeshType * GetOutput(void);
  OutputMeshType * GetOutput(unsigned int idx);
  
  /** Set the mesh output of this process object. This call is slated
   * to be removed from ITK. You should GraftOutput() and possible
   * DataObject::DisconnectPipeline() to properly change the output. */
  void SetOutput(TOutputMesh *output);

  /** Graft the specified DataObject onto this ProcessObject's output.
   * This method grabs a handle to the specified DataObject's bulk
   * data to used as its output's own bulk data. It also copies the
   * region ivars (RequestedRegion, BufferedRegion,
   * LargestPossibleRegion) and meta-data (Spacing, Origin) from the
   * specified data object into this filter's output data object. Most
   * importantly, however, it leaves the Source ivar untouched so the
   * original pipeline routing is intact. This method is used when a
   * process object is implemented using a mini-pipeline which is
   * defined in its GenerateData() method.  The usage is:
   *
   * \code
   *    // setup the mini-pipeline to process the input to this filter
   *    firstFilterInMiniPipeline->SetInput( this->GetInput() );
   *
   *    // setup the mini-pipeline to calculate the correct regions
   *    // and write to the appropriate bulk data block
   *    lastFilterInMiniPipeline->GraftOutput( this->GetOutput() );
   *
   *    // execute the mini-pipeline
   *    lastFilterInMiniPipeline->Update();
   *
   *    // graft the mini-pipeline output back onto this filter's output.
   *    // this is needed to get the appropriate regions passed back.
   *    this->GraftOutput( lastFilterInMiniPipeline->GetOutput() );
   * \endcode
   *
   * For proper pipeline execution, a filter using a mini-pipeline
   * must implement the GenerateInputRequestedRegion(),
   * GenerateOutputRequestedRegion(), GenerateOutputInformation() and
   * EnlargeOutputRequestedRegion() methods as necessary to reflect
   * how the mini-pipeline will execute (in other words, the outer
   * filter's pipeline mechanism must be consistent with what the
   * mini-pipeline will do). */
  virtual void GraftOutput(DataObject *output);
  virtual void GraftNthOutput(unsigned int idx, DataObject *output);

  /** Make a DataObject of the correct type to used as the specified
   * output.  Every ProcessObject subclass must be able to create a
   * DataObject that can be used as a specified output. This method
   * is automatically called when DataObject::DisconnectPipeline() is
   * called.  DataObject::DisconnectPipeline, disconnects a data object
   * from being an output of its current source.  When the data object
   * is disconnected, the ProcessObject needs to construct a replacement
   * output data object so that the ProcessObject is in a valid state.
   * So DataObject::DisconnectPipeline eventually calls
   * ProcessObject::MakeOutput. Note that MakeOutput always returns a
   * SmartPointer to a DataObject. If a subclass of MeshSource has
   * multiple outputs of different types, then that class must provide
   * an implementation of MakeOutput(). */
  virtual DataObjectPointer MakeOutput(unsigned int idx);

protected:
  MeshSource();
  virtual ~MeshSource() {}
  void PrintSelf(std::ostream& os, Indent indent) const;
  
  /** Requested region of Mesh is specified as i of N unstructured regions.
   * Since all DataObjects should be able to set the requested region in 
   * unstructured form, just copy output->RequestedRegion all inputs. */
  void GenerateInputRequestedRegion();
  
private:
  MeshSource(const Self&); //purposely not implemented
  void operator=(const Self&); //purposely not implemented

  /** Used by streaming: The requested region of the output being processed
   * by the execute method. Set in the GenerateInputRequestedRegion method. */
  int m_GenerateDataRegion;
  int m_GenerateDataNumberOfRegions;
  };

} // end namespace itk

#ifndef ITK_MANUAL_INSTANTIATION
#include "itkMeshSource.txx"
#endif

#endif
  
