/usr/include/vtk-6.3/vtkFiniteDifferenceGradientEstimator.h is in libvtk6-dev 6.3.0+dfsg1-11build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 | /*=========================================================================
Program: Visualization Toolkit
Module: vtkFiniteDifferenceGradientEstimator.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 vtkFiniteDifferenceGradientEstimator - Use finite differences to estimate gradient.
//
// .SECTION Description
// vtkFiniteDifferenceGradientEstimator is a concrete subclass of
// vtkEncodedGradientEstimator that uses a central differences technique to
// estimate the gradient. The gradient at some sample location (x,y,z)
// would be estimated by:
//
// nx = (f(x-dx,y,z) - f(x+dx,y,z)) / 2*dx;
// ny = (f(x,y-dy,z) - f(x,y+dy,z)) / 2*dy;
// nz = (f(x,y,z-dz) - f(x,y,z+dz)) / 2*dz;
//
// This value is normalized to determine a unit direction vector and a
// magnitude. The normal is computed in voxel space, and
// dx = dy = dz = SampleSpacingInVoxels. A scaling factor is applied to
// convert this normal from voxel space to world coordinates.
//
// .SECTION see also
// vtkEncodedGradientEstimator
#ifndef vtkFiniteDifferenceGradientEstimator_h
#define vtkFiniteDifferenceGradientEstimator_h
#include "vtkRenderingVolumeModule.h" // For export macro
#include "vtkEncodedGradientEstimator.h"
class VTKRENDERINGVOLUME_EXPORT vtkFiniteDifferenceGradientEstimator : public vtkEncodedGradientEstimator
{
public:
vtkTypeMacro(vtkFiniteDifferenceGradientEstimator,vtkEncodedGradientEstimator);
void PrintSelf( ostream& os, vtkIndent indent );
// Description:
// Construct a vtkFiniteDifferenceGradientEstimator with
// a SampleSpacingInVoxels of 1.
static vtkFiniteDifferenceGradientEstimator *New();
// Description:
// Set/Get the spacing between samples for the finite differences
// method used to compute the normal. This spacing is in voxel units.
vtkSetMacro( SampleSpacingInVoxels, int );
vtkGetMacro( SampleSpacingInVoxels, int );
// The sample spacing between samples taken for the normal estimation
int SampleSpacingInVoxels;
protected:
vtkFiniteDifferenceGradientEstimator();
~vtkFiniteDifferenceGradientEstimator();
// Description:
// Recompute the encoded normals and gradient magnitudes.
void UpdateNormals( void );
private:
vtkFiniteDifferenceGradientEstimator(const vtkFiniteDifferenceGradientEstimator&); // Not implemented.
void operator=(const vtkFiniteDifferenceGradientEstimator&); // Not implemented.
};
#endif
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