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/*=========================================================================
Program: Visualization Toolkit
Module: vtkAttributesErrorMetric.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 vtkAttributesErrorMetric - Objects that compute
// attribute-based error during cell tessellation.
//
// .SECTION Description
// It is a concrete error metric, based on an attribute criterium:
// the variation of the active attribute/component value from a linear ramp
//
// .SECTION See Also
// vtkGenericCellTessellator vtkGenericSubdivisionErrorMetric
#ifndef __vtkAttributesErrorMetric_h
#define __vtkAttributesErrorMetric_h
#include "vtkGenericSubdivisionErrorMetric.h"
class vtkGenericAttributeCollection;
class vtkGenericDataSet;
class VTK_FILTERING_EXPORT vtkAttributesErrorMetric : public vtkGenericSubdivisionErrorMetric
{
public:
// Description:
// Construct the error metric with a default relative attribute accuracy
// equal to 0.1.
static vtkAttributesErrorMetric *New();
// Description:
// Standard VTK type and error macros.
vtkTypeMacro(vtkAttributesErrorMetric,vtkGenericSubdivisionErrorMetric);
void PrintSelf(ostream& os, vtkIndent indent);
// Description:
// Absolute tolerance of the active scalar (attribute+component).
// Subdivision is required if the square distance between the real attribute
// at the mid point on the edge and the interpolated attribute is greater
// than AbsoluteAttributeTolerance.
// This is the attribute accuracy.
// 0.01 will give better result than 0.1.
vtkGetMacro(AbsoluteAttributeTolerance, double);
// Description:
// Set the absolute attribute accuracy to `value'. See
// GetAbsoluteAttributeTolerance() for details.
// It is particularly useful when some concrete implementation of
// vtkGenericAttribute does not support GetRange() request, called
// internally in SetAttributeTolerance(). It may happen when the
// implementation support higher order attributes but
// cannot compute the range.
// \pre valid_range_value: value>0
void SetAbsoluteAttributeTolerance(double value);
// Description:
// Relative tolerance of the active scalar (attribute+component).
// Subdivision is required if the square distance between the real attribute
// at the mid point on the edge and the interpolated attribute is greater
// than AttributeTolerance.
// This is the attribute accuracy.
// 0.01 will give better result than 0.1.
vtkGetMacro(AttributeTolerance, double);
// Description:
// Set the relative attribute accuracy to `value'. See
// GetAttributeTolerance() for details.
// \pre valid_range_value: value>0 && value<1
void SetAttributeTolerance(double value);
// Description:
// Does the edge need to be subdivided according to the distance between
// the value of the active attribute/component at the midpoint and the mean
// value between the endpoints?
// The edge is defined by its `leftPoint' and its `rightPoint'.
// `leftPoint', `midPoint' and `rightPoint' have to be initialized before
// calling RequiresEdgeSubdivision().
// Their format is global coordinates, parametric coordinates and
// point centered attributes: xyx rst abc de...
// `alpha' is the normalized abscissa of the midpoint along the edge.
// (close to 0 means close to the left point, close to 1 means close to the
// right point)
// \pre leftPoint_exists: leftPoint!=0
// \pre midPoint_exists: midPoint!=0
// \pre rightPoint_exists: rightPoint!=0
// \pre clamped_alpha: alpha>0 && alpha<1
// \pre valid_size: sizeof(leftPoint)=sizeof(midPoint)=sizeof(rightPoint)
// =GetAttributeCollection()->GetNumberOfPointCenteredComponents()+6
int RequiresEdgeSubdivision(double *leftPoint, double *midPoint, double *rightPoint,
double alpha);
// Description:
// Return the error at the mid-point. The type of error depends on the state
// of the concrete error metric. For instance, it can return an absolute
// or relative error metric.
// See RequiresEdgeSubdivision() for a description of the arguments.
// \pre leftPoint_exists: leftPoint!=0
// \pre midPoint_exists: midPoint!=0
// \pre rightPoint_exists: rightPoint!=0
// \pre clamped_alpha: alpha>0 && alpha<1
// \pre valid_size: sizeof(leftPoint)=sizeof(midPoint)=sizeof(rightPoint)
// =GetAttributeCollection()->GetNumberOfPointCenteredComponents()+6
// \post positive_result: result>=0
double GetError(double *leftPoint, double *midPoint,
double *rightPoint, double alpha);
protected:
vtkAttributesErrorMetric();
virtual ~vtkAttributesErrorMetric();
// Description:
// Compute the square absolute attribute tolerance, only if the cached value
// is obsolete.
void ComputeSquareAbsoluteAttributeTolerance();
double AttributeTolerance;
double SquareAbsoluteAttributeTolerance; // cached value computed from
// AttributeTolerance and active attribute/component
double AbsoluteAttributeTolerance;
int DefinedByAbsolute;
vtkTimeStamp SquareAbsoluteAttributeToleranceComputeTime;
double Range; // cached value computed from active attribute/component
vtkGenericAttributeCollection *AttributeCollection;
private:
vtkAttributesErrorMetric(const vtkAttributesErrorMetric&); // Not implemented.
void operator=(const vtkAttributesErrorMetric&); // Not implemented.
};
#endif