You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

133 lines
5.1 KiB
C++

/*=========================================================================
Program: Visualization Toolkit
Module: vtkInterpolatedVelocityField.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.
=========================================================================*/
/**
* @class vtkInterpolatedVelocityField
* @brief A concrete class for obtaining
* the interpolated velocity values at a point.
*
*
* vtkInterpolatedVelocityField acts as a continuous velocity field via
* cell interpolation on a vtkDataSet, NumberOfIndependentVariables = 4
* (x,y,z,t) and NumberOfFunctions = 3 (u,v,w). As a concrete sub-class
* of vtkCompositeInterpolatedVelocityField, this class adopts two levels
* of cell caching for faster though less robust cell location than its
* sibling class vtkCellLocatorInterpolatedVelocityField. Level #0 begins
* with intra-cell caching. Specifically, if the previous cell is valid
* and the next point is still within it, ( vtkCell::EvaluatePosition()
* returns 1, coupled with the new parametric coordinates and weights ),
* the function values are interpolated and vtkCell::EvaluatePosition()
* is invoked only. If it fails, level #1 follows by inter-cell location
* of the target cell (that contains the next point). By inter-cell, the
* previous cell gives an important clue / guess or serves as an immediate
* neighbor to aid in the location of the target cell (as is typically the
* case with integrating a streamline across cells) by means of vtkDataSet::
* FindCell(). If this still fails, a global cell search is invoked via
* vtkDataSet::FindCell().
*
* Regardless of inter-cell or global search, a point locator is employed as
* a crucial tool underlying the interpolation process. The use of a point
* locator, while faster than a cell locator, is not optimal and may cause
* vtkInterpolatedVelocityField to return incorrect results (i.e., premature
* streamline termination) for datasets defined on complex grids (especially
* those this discontinuous/incompatible cells). In these cases, try
* vtkCellLocatorInterpolatedVelocityField which produces the best results at
* the cost of speed.
*
* @warning
* vtkInterpolatedVelocityField is not thread safe. A new instance should be
* created by each thread.
*
* @sa
* vtkCompositeInterpolatedVelocityField vtkCellLocatorInterpolatedVelocityField
* vtkGenericInterpolatedVelocityField vtkCachingInterpolatedVelocityField
* vtkTemporalInterpolatedVelocityField vtkFunctionSet vtkStreamTracer
*/
#ifndef vtkInterpolatedVelocityField_h
#define vtkInterpolatedVelocityField_h
#include "vtkCompositeInterpolatedVelocityField.h"
#include "vtkFiltersFlowPathsModule.h" // For export macro
class VTKFILTERSFLOWPATHS_EXPORT vtkInterpolatedVelocityField
: public vtkCompositeInterpolatedVelocityField
{
public:
/**
* Construct a vtkInterpolatedVelocityField without an initial dataset.
* Caching is set on and LastCellId is set to -1.
*/
static vtkInterpolatedVelocityField* New();
//@{
/**
* Standard methods for type information and printing.
*/
vtkTypeMacro(vtkInterpolatedVelocityField, vtkCompositeInterpolatedVelocityField);
void PrintSelf(ostream& os, vtkIndent indent) override;
//@}
/**
* Add a dataset used for the implicit function evaluation. If more than
* one dataset is added, the evaluation point is searched in all until a
* match is found. THIS FUNCTION DOES NOT CHANGE THE REFERENCE COUNT OF
* DATASET FOR THREAD SAFETY REASONS.
*/
void AddDataSet(vtkDataSet* dataset) override;
using Superclass::FunctionValues;
/**
* Evaluate the velocity field f at point (x, y, z).
*/
int FunctionValues(double* x, double* f) override;
/**
* Project the provided point on current cell, current dataset.
*/
virtual int SnapPointOnCell(double* pOrigin, double* pProj);
/**
* Set the cell id cached by the last evaluation within a specified dataset.
*/
void SetLastCellId(vtkIdType c, int dataindex) override;
/**
* Set the cell id cached by the last evaluation.
*/
void SetLastCellId(vtkIdType c) override { this->Superclass::SetLastCellId(c); }
protected:
vtkInterpolatedVelocityField() {}
~vtkInterpolatedVelocityField() override {}
/**
* Evaluate the velocity field f at point (x, y, z) in a specified dataset
* by either involving vtkPointLocator, via vtkPointSet::FindCell(), in
* locating the next cell (for datasets of type vtkPointSet) or simply
* invoking vtkImageData/vtkRectilinearGrid::FindCell() to fulfill the same
* task if the point is outside the current cell.
*/
int FunctionValues(vtkDataSet* ds, double* x, double* f) override
{
return this->Superclass::FunctionValues(ds, x, f);
}
private:
vtkInterpolatedVelocityField(const vtkInterpolatedVelocityField&) = delete;
void operator=(const vtkInterpolatedVelocityField&) = delete;
};
#endif