VTK-5.0.0/Graphics/vtkConnectivityFilter.h

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

  Program:   Visualization Toolkit
  Module:    $RCSfile: vtkConnectivityFilter.h,v $

  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 vtkConnectivityFilter - extract data based on geometric connectivity
// .SECTION Description
// vtkConnectivityFilter is a filter that extracts cells that share common
// points and/or meet other connectivity criterion. (Cells that share
// vertices and meet other connectivity criterion such as scalar range are
// known as a region.)  The filter works in one of six ways: 1) extract the
// largest connected region in the dataset; 2) extract specified region
// numbers; 3) extract all regions sharing specified point ids; 4) extract
// all regions sharing specified cell ids; 5) extract the region closest to
// the specified point; or 6) extract all regions (used to color the data by
// region).
//
// vtkConnectivityFilter is generalized to handle any type of input dataset.
// It generates output data of type vtkUnstructuredGrid. If you know that
// your input type is vtkPolyData, you may wish to use
// vtkPolyDataConnectivityFilter.
//
// The behavior of vtkConnectivityFilter can be modified by turning on the
// boolean ivar ScalarConnectivity. If this flag is on, the connectivity
// algorithm is modified so that cells are considered connected only if 1)
// they are geometrically connected (share a point) and 2) the scalar values
// of one of the cell's points falls in the scalar range specified. This use
// of ScalarConnectivity is particularly useful for volume datasets: it can
// be used as a simple "connected segmentation" algorithm. For example, by
// using a seed voxel (i.e., cell) on a known anatomical structure,
// connectivity will pull out all voxels "containing" the anatomical
// structure. These voxels can then be contoured or processed by other
// visualization filters.

// .SECTION See Also
// vtkPolyDataConnectivityFilter

#ifndef __vtkConnectivityFilter_h
#define __vtkConnectivityFilter_h

#include "vtkUnstructuredGridAlgorithm.h"

#define VTK_EXTRACT_POINT_SEEDED_REGIONS 1
#define VTK_EXTRACT_CELL_SEEDED_REGIONS 2
#define VTK_EXTRACT_SPECIFIED_REGIONS 3
#define VTK_EXTRACT_LARGEST_REGION 4
#define VTK_EXTRACT_ALL_REGIONS 5
#define VTK_EXTRACT_CLOSEST_POINT_REGION 6

class vtkDataArray;
class vtkFloatArray;
class vtkIdList;
class vtkIntArray;

class VTK_GRAPHICS_EXPORT vtkConnectivityFilter : public vtkUnstructuredGridAlgorithm
{
public:
  vtkTypeRevisionMacro(vtkConnectivityFilter,vtkUnstructuredGridAlgorithm);
  void PrintSelf(ostream& os, vtkIndent indent);

  // Description:
  // Construct with default extraction mode to extract largest regions.
  static vtkConnectivityFilter *New();

  // Description:
  // Turn on/off connectivity based on scalar value. If on, cells are connected
  // only if they share points AND one of the cells scalar values falls in the
  // scalar range specified.
  vtkSetMacro(ScalarConnectivity,int);
  vtkGetMacro(ScalarConnectivity,int);
  vtkBooleanMacro(ScalarConnectivity,int);

  // Description:
  // Set the scalar range to use to extract cells based on scalar connectivity.
  vtkSetVector2Macro(ScalarRange,double);
  vtkGetVector2Macro(ScalarRange,double);

  // Description:
  // Control the extraction of connected surfaces.
  vtkSetClampMacro(ExtractionMode,int,
            VTK_EXTRACT_POINT_SEEDED_REGIONS,VTK_EXTRACT_CLOSEST_POINT_REGION);
  vtkGetMacro(ExtractionMode,int);
  void SetExtractionModeToPointSeededRegions()
    {this->SetExtractionMode(VTK_EXTRACT_POINT_SEEDED_REGIONS);};
  void SetExtractionModeToCellSeededRegions()
    {this->SetExtractionMode(VTK_EXTRACT_CELL_SEEDED_REGIONS);};
  void SetExtractionModeToLargestRegion()
    {this->SetExtractionMode(VTK_EXTRACT_LARGEST_REGION);};
  void SetExtractionModeToSpecifiedRegions()
    {this->SetExtractionMode(VTK_EXTRACT_SPECIFIED_REGIONS);};
  void SetExtractionModeToClosestPointRegion()
    {this->SetExtractionMode(VTK_EXTRACT_CLOSEST_POINT_REGION);};
  void SetExtractionModeToAllRegions()
    {this->SetExtractionMode(VTK_EXTRACT_ALL_REGIONS);};
  const char *GetExtractionModeAsString();

  // Description:
  // Initialize list of point ids/cell ids used to seed regions.
  void InitializeSeedList();

  // Description:
  // Add a seed id (point or cell id). Note: ids are 0-offset.
  void AddSeed(vtkIdType id);

  // Description:
  // Delete a seed id (point or cell id). Note: ids are 0-offset.
  void DeleteSeed(vtkIdType id);

  // Description:
  // Initialize list of region ids to extract.
  void InitializeSpecifiedRegionList();

  // Description:
  // Add a region id to extract. Note: ids are 0-offset.
  void AddSpecifiedRegion(int id);

  // Description:
  // Delete a region id to extract. Note: ids are 0-offset.
  void DeleteSpecifiedRegion(int id);

  // Description:
  // Use to specify x-y-z point coordinates when extracting the region 
  // closest to a specified point.
  vtkSetVector3Macro(ClosestPoint,double);
  vtkGetVectorMacro(ClosestPoint,double,3);

  // Description:
  // Obtain the number of connected regions.
  int GetNumberOfExtractedRegions();

  // Description:
  // Turn on/off the coloring of connected regions.
  vtkSetMacro(ColorRegions,int);
  vtkGetMacro(ColorRegions,int);
  vtkBooleanMacro(ColorRegions,int);

protected:
  vtkConnectivityFilter();
  ~vtkConnectivityFilter();

  // Usual data generation method
  virtual int RequestData(vtkInformation *, vtkInformationVector **, vtkInformationVector *);
  virtual int FillInputPortInformation(int port, vtkInformation *info);

  int ColorRegions; //boolean turns on/off scalar gen for separate regions
  int ExtractionMode; //how to extract regions
  vtkIdList *Seeds; //id's of points or cells used to seed regions
  vtkIdList *SpecifiedRegionIds; //regions specified for extraction
  vtkIntArray *RegionSizes; //size (in cells) of each region extracted

  double ClosestPoint[3];

  int ScalarConnectivity;
  double ScalarRange[2];

  void TraverseAndMark(vtkDataSet *input);

private:
  // used to support algorithm execution
  vtkFloatArray *CellScalars;
  vtkIdList *NeighborCellPointIds;
  vtkIdType *Visited;
  vtkIdType *PointMap;
  vtkFloatArray *NewScalars;
  int RegionNumber;
  vtkIdType PointNumber;    
  int NumCellsInRegion;
  vtkDataArray *InScalars;
  vtkIdList *Wave;
  vtkIdList *Wave2;
  vtkIdList *PointIds;
  vtkIdList *CellIds;
private:
  vtkConnectivityFilter(const vtkConnectivityFilter&);  // Not implemented.
  void operator=(const vtkConnectivityFilter&);  // Not implemented.
};

// Description:
// Return the method of extraction as a string.
inline const char *vtkConnectivityFilter::GetExtractionModeAsString(void)
{
  if ( this->ExtractionMode == VTK_EXTRACT_POINT_SEEDED_REGIONS ) 
    {
    return "ExtractPointSeededRegions";
    }
  else if ( this->ExtractionMode == VTK_EXTRACT_CELL_SEEDED_REGIONS ) 
    {
    return "ExtractCellSeededRegions";
    }
  else if ( this->ExtractionMode == VTK_EXTRACT_SPECIFIED_REGIONS ) 
    {
    return "ExtractSpecifiedRegions";
    }
  else if ( this->ExtractionMode == VTK_EXTRACT_ALL_REGIONS ) 
    {
    return "ExtractAllRegions";
    }
  else if ( this->ExtractionMode == VTK_EXTRACT_CLOSEST_POINT_REGION ) 
    {
    return "ExtractClosestPointRegion";
    }
  else 
    {
    return "ExtractLargestRegion";
    }
}

#endif