dox/Graphics/vtkStreamer.h

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

  Program:   Visualization Toolkit
  Module:    vtkStreamer.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.

=========================================================================*/
#ifndef __vtkStreamer_h
#define __vtkStreamer_h

#include "vtkPolyDataAlgorithm.h"

class vtkInitialValueProblemSolver;
class vtkMultiThreader;

#define VTK_INTEGRATE_FORWARD 0
#define VTK_INTEGRATE_BACKWARD 1
#define VTK_INTEGRATE_BOTH_DIRECTIONS 2

class VTK_GRAPHICS_EXPORT vtkStreamer : public vtkPolyDataAlgorithm
{
public:
  vtkTypeMacro(vtkStreamer,vtkPolyDataAlgorithm);
  void PrintSelf(ostream& os, vtkIndent indent);

  void SetStartLocation(vtkIdType cellId, int subId, double pcoords[3]);


  void SetStartLocation(vtkIdType cellId, int subId, double r, double s,
                        double t);

  vtkIdType GetStartLocation(int& subId, double pcoords[3]);

  void SetStartPosition(double x[3]);

  void SetStartPosition(double x, double y, double z);

  double *GetStartPosition();


  void SetSource(vtkDataSet *source);
  vtkDataSet *GetSource();


  vtkSetClampMacro(MaximumPropagationTime,double,0.0,VTK_DOUBLE_MAX);
  vtkGetMacro(MaximumPropagationTime,double);


  vtkSetClampMacro(IntegrationDirection,int,
                   VTK_INTEGRATE_FORWARD,VTK_INTEGRATE_BOTH_DIRECTIONS);
  vtkGetMacro(IntegrationDirection,int);
  void SetIntegrationDirectionToForward()
    {this->SetIntegrationDirection(VTK_INTEGRATE_FORWARD);};
  void SetIntegrationDirectionToBackward()
    {this->SetIntegrationDirection(VTK_INTEGRATE_BACKWARD);};
  void SetIntegrationDirectionToIntegrateBothDirections()
    {this->SetIntegrationDirection(VTK_INTEGRATE_BOTH_DIRECTIONS);};
  const char *GetIntegrationDirectionAsString();


  vtkSetClampMacro(IntegrationStepLength,double,0.0000001,VTK_DOUBLE_MAX);
  vtkGetMacro(IntegrationStepLength,double);


  vtkSetMacro(SpeedScalars,int);
  vtkGetMacro(SpeedScalars,int);
  vtkBooleanMacro(SpeedScalars,int);


  vtkSetMacro(OrientationScalars, int);
  vtkGetMacro(OrientationScalars, int);
  vtkBooleanMacro(OrientationScalars, int);


  vtkSetClampMacro(TerminalSpeed,double,0.0,VTK_DOUBLE_MAX);
  vtkGetMacro(TerminalSpeed,double);


  vtkSetMacro(Vorticity,int);
  vtkGetMacro(Vorticity,int);
  vtkBooleanMacro(Vorticity,int);

  vtkSetMacro( NumberOfThreads, int );
  vtkGetMacro( NumberOfThreads, int );

  vtkSetMacro( SavePointInterval, double );
  vtkGetMacro( SavePointInterval, double );


  void SetIntegrator(vtkInitialValueProblemSolver *);
  vtkGetObjectMacro ( Integrator, vtkInitialValueProblemSolver );


  vtkSetMacro(Epsilon,double);
  vtkGetMacro(Epsilon,double);
  
protected:

  vtkStreamer();
  ~vtkStreamer();

  // Integrate data
  void Integrate(vtkDataSet *input, vtkDataSet *source);

  // Controls where streamlines start from (either position or location).
  int StartFrom;

  // Starting from cell location
  vtkIdType StartCell;
  int StartSubId;
  double StartPCoords[3];

  // starting from global x-y-z position
  double StartPosition[3];

  //
  // Special classes for manipulating data
  //
  //BTX - begin tcl exclude
  //
  class StreamPoint {
  public:
    double    x[3];    // position 
    vtkIdType cellId;  // cell
    int       subId;   // cell sub id
    double    p[3];    // parametric coords in cell 
    double    v[3];    // velocity 
    double    speed;   // velocity norm 
    double    s;       // scalar value 
    double    t;       // time travelled so far 
    double    d;       // distance travelled so far 
    double    omega;   // stream vorticity, if computed
    double    theta;   // rotation angle, if vorticity is computed
  };

  class StreamArray;
  friend class StreamArray;
  class StreamArray { //;prevent man page generation
  public:
    StreamArray();
    ~StreamArray()
      {
        if (this->Array)
          {
          delete [] this->Array;
          }
      };
    vtkIdType GetNumberOfPoints() {return this->MaxId + 1;};
    StreamPoint *GetStreamPoint(vtkIdType i) {return this->Array + i;};
    vtkIdType InsertNextStreamPoint() 
      {
        if ( ++this->MaxId >= this->Size )
          {
          this->Resize(this->MaxId);
          }
        return this->MaxId; //return offset from array
      }
    StreamPoint *Resize(vtkIdType sz); //reallocates data
    void Reset() {this->MaxId = -1;};

    StreamPoint *Array;     // pointer to data
    vtkIdType MaxId;        // maximum index inserted thus far
    vtkIdType Size;         // allocated size of data
    vtkIdType Extend;       // grow array by this amount
    double Direction;       // integration direction
  };
  //ETX
  //

  //array of streamers
  StreamArray *Streamers;
  vtkIdType NumberOfStreamers;

  // length of Streamer is generated by time, or by MaximumSteps
  double MaximumPropagationTime;

  // integration direction
  int IntegrationDirection;

  // the length (fraction of cell size) of integration steps
  double IntegrationStepLength;

  // boolean controls whether vorticity is computed
  int Vorticity;

  // terminal propagation speed
  double TerminalSpeed;

  // boolean controls whether data scalars or velocity magnitude are used
  int SpeedScalars;

  // boolean controls whether data scalars or vorticity orientation are used
  int OrientationScalars;

  // Prototype showing the integrator type to be set by the user.
  vtkInitialValueProblemSolver* Integrator;

  // A positive value, as small as possible for numerical comparison.
  // The initial value is 1E-12.
  double Epsilon;
  
  // Interval with which the stream points will be stored.
  // Useful in reducing the memory footprint. Since the initial
  // value is small, by default, it will store all/most points.
  double SavePointInterval;

  static VTK_THREAD_RETURN_TYPE ThreadedIntegrate( void *arg );


  vtkGetMacro( NumberOfStreamers, vtkIdType );
  StreamArray *GetStreamers() { return this->Streamers; };

  void InitializeThreadedIntegrate();
  vtkMultiThreader           *Threader;
  int                        NumberOfThreads;

  virtual int FillInputPortInformation(int port, vtkInformation *info);

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


inline const char *vtkStreamer::GetIntegrationDirectionAsString()
{
  if ( this->IntegrationDirection == VTK_INTEGRATE_FORWARD ) 
    {
    return "IntegrateForward";
    }
  else if ( this->IntegrationDirection == VTK_INTEGRATE_BACKWARD ) 
    {
    return "IntegrateBackward";
    }
  else 
    {
    return "IntegrateBothDirections";
    }
}

#endif

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