text: /*=========================================================================
  
    Program:   Visualization Toolkit
    Module:    vtkConnectivityFilter.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 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 vtkIdTypeArray;
  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
    vtkIdTypeArray *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;
    vtkIdTypeArray *NewScalars;
    vtkIdTypeArray *NewCellScalars;
    vtkIdType RegionNumber;
    vtkIdType PointNumber;    
    vtkIdType 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
  
  
  