paraview-dev 5.1.2+dfsg1-2 / usr / include / paraview / vtkGaussianKernel.h

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

  Program:   Visualization Toolkit
  Module:    vtkGaussianKernel.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 vtkGaussianKernel - a spherical Gaussian interpolation kernel

// .SECTION Description
// vtkGaussianKernel is an interpolation kernel that simply returns the
// weights for all points found in the sphere defined by radius R. The
// weights are computed as: exp(-(s*r/R)^2) where r is the distance from the
// point to be interpolated to a neighboring point within R. The sharpness s
// simply affects the rate of fall off of the Gaussian. (A more general
// Gaussian kernel is available from vtkEllipsoidalGaussianKernel.)

// .SECTION Caveats
// The weights are normalized sp that SUM(Wi) = 1. If a neighbor point p
// precisely lies on the point to be interpolated, then the interpolated
// point takes on the values associated with p.

// .SECTION See Also
// vtkPointInterpolator vtkInterpolationKernel vtkEllipsoidalGaussianKernel
// vtkVoronoiKernel vtkSPHKernel vtkShepardKernel


#ifndef vtkGaussianKernel_h
#define vtkGaussianKernel_h

#include "vtkFiltersPointsModule.h" // For export macro
#include "vtkGeneralizedKernel.h"

class vtkIdList;
class vtkDoubleArray;


class VTKFILTERSPOINTS_EXPORT vtkGaussianKernel : public vtkGeneralizedKernel
{
public:
  // Description:
  // Standard methods for instantiation, obtaining type information, and printing.
  static vtkGaussianKernel *New();
  vtkTypeMacro(vtkGaussianKernel,vtkGeneralizedKernel);
  void PrintSelf(ostream& os, vtkIndent indent);

  // Description:
  // Initialize the kernel. Overload the superclass to set up internal
  // computational values.
  virtual void Initialize(vtkAbstractPointLocator *loc, vtkDataSet *ds,
                          vtkPointData *pd);

  // Re-use any superclass signatures that we don't override.
  using vtkGeneralizedKernel::ComputeWeights;

  // Description:
  // Given a point x, a list of basis points pIds, and a probability
  // weighting function prob, compute interpolation weights associated with
  // these basis points.  Note that basis points list pIds, the probability
  // weighting prob, and the weights array are provided by the caller of the
  // method, and may be dynamically resized as necessary. The method returns
  // the number of weights (pIds may be resized in some cases). Typically
  // this method is called after ComputeBasis(), although advanced users can
  // invoke ComputeWeights() and provide the interpolation basis points pIds
  // directly. The probably weighting prob are numbers 0<=prob<=1 which are
  // multiplied against the interpolation weights before normalization. They
  // are estimates of local confidence of weights. The prob may be NULL in
  // which all probabilities are considered =1.
  virtual vtkIdType ComputeWeights(double x[3], vtkIdList *pIds,
                                   vtkDoubleArray *prob, vtkDoubleArray *weights);

  // Description:
  // Set / Get the sharpness (i.e., falloff) of the Gaussian. By default
  // Sharpness=2. As the sharpness increases the effects of distant points
  // are reduced.
  vtkSetClampMacro(Sharpness,double,1,VTK_FLOAT_MAX);
  vtkGetMacro(Sharpness,double);

protected:
  vtkGaussianKernel();
  ~vtkGaussianKernel();

  double Sharpness;

  // Internal structure to reduce computation
  double F2;

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

#endif