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/*=========================================================================
Program: Visualization Toolkit
Module: vtkCellLocator.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 vtkCellLocator
* @brief octree-based spatial search object to quickly locate cells
*
* vtkCellLocator is a spatial search object to quickly locate cells in 3D.
* vtkCellLocator uses a uniform-level octree subdivision, where each octant
* (an octant is also referred to as a bucket) carries an indication of
* whether it is empty or not, and each leaf octant carries a list of the
* cells inside of it. (An octant is not empty if it has one or more cells
* inside of it.) Typical operations are intersection with a line to return
* candidate cells, or intersection with another vtkCellLocator to return
* candidate cells.
*
* @warning
* Many other types of spatial locators have been developed, such as
* variable depth octrees and kd-trees. These are often more efficient
* for the operations described here. vtkCellLocator has been designed
* for subclassing; so these locators can be derived if necessary.
*
* @warning
* Most of the methods of this class are not thread-safe. For a thread-safe,
* more efficient generic implementation, please use vtkStaticCellLocator
*
* @sa
* vtkLocator vtkPointLocator vtkOBBTree vtkStaticCellLocator
*/
#ifndef vtkCellLocator_h
#define vtkCellLocator_h
#include "vtkAbstractCellLocator.h"
#include "vtkCommonDataModelModule.h" // For export macro
class vtkNeighborCells;
class VTKCOMMONDATAMODEL_EXPORT vtkCellLocator : public vtkAbstractCellLocator
{
public:
vtkTypeMacro(vtkCellLocator, vtkAbstractCellLocator);
void PrintSelf(ostream& os, vtkIndent indent) override;
/**
* Construct with automatic computation of divisions, averaging
* 25 cells per bucket.
*/
static vtkCellLocator* New();
/**
* Specify the average number of cells in each octant.
*/
void SetNumberOfCellsPerBucket(int N) { this->SetNumberOfCellsPerNode(N); }
int GetNumberOfCellsPerBucket() { return this->NumberOfCellsPerNode; }
// Re-use any superclass signatures that we don't override.
using vtkAbstractCellLocator::FindCell;
using vtkAbstractCellLocator::FindClosestPoint;
using vtkAbstractCellLocator::FindClosestPointWithinRadius;
using vtkAbstractCellLocator::IntersectWithLine;
/**
* Return intersection point (if any) AND the cell which was intersected by
* the finite line. The cell is returned as a cell id and as a generic
* cell. For other IntersectWithLine signatures, see
* vtkAbstractCellLocator.
* THIS METHOD IS NOT THREAD SAFE.
*/
int IntersectWithLine(const double a0[3], const double a1[3], double tol, double& t, double x[3],
double pcoords[3], int& subId, vtkIdType& cellId, vtkGenericCell* cell) override;
/**
* Return the closest point and the cell which is closest to the point x.
* The closest point is somewhere on a cell, it need not be one of the
* vertices of the cell. This version takes in a vtkGenericCell
* to avoid allocating and deallocating the cell. This is much faster than
* the version which does not take a *cell, especially when this function is
* called many times in a row such as by a for loop, where the allocation and
* deallocation can be done only once outside the for loop. If a cell is
* found, "cell" contains the points and ptIds for the cell "cellId" upon
* exit.
* THIS METHOD IS NOT THREAD SAFE.
*/
void FindClosestPoint(const double x[3], double closestPoint[3], vtkGenericCell* cell,
vtkIdType& cellId, int& subId, double& dist2) override;
/**
* Return the closest point within a specified radius and the cell which is
* closest to the point x. The closest point is somewhere on a cell, it
* need not be one of the vertices of the cell. This method returns 1 if a
* point is found within the specified radius. If there are no cells within
* the specified radius, the method returns 0 and the values of
* closestPoint, cellId, subId, and dist2 are undefined. This version takes
* in a vtkGenericCell to avoid allocating and deallocating the cell. This
* is much faster than the version which does not take a *cell, especially
* when this function is called many times in a row such as by a for loop,
* where the allocation and dealloction can be done only once outside the
* for loop. If a closest point is found, "cell" contains the points and
* ptIds for the cell "cellId" upon exit. If a closest point is found,
* inside returns the return value of the EvaluatePosition call to the
* closest cell; inside(=1) or outside(=0). For other
* FindClosestPointWithinRadius signatures, see vtkAbstractCellLocator.
* THIS METHOD IS NOT THREAD SAFE.
*/
vtkIdType FindClosestPointWithinRadius(double x[3], double radius, double closestPoint[3],
vtkGenericCell* cell, vtkIdType& cellId, int& subId, double& dist2, int& inside) override;
/**
* Get the cells in a particular bucket.
*/
virtual vtkIdList* GetCells(int bucket);
/**
* Return number of buckets available. Insure that the locator has been
* built before attempting to access buckets (octants).
*/
virtual int GetNumberOfBuckets(void);
/**
* Find the cell containing a given point. returns -1 if no cell found
* the cell parameters are copied into the supplied variables, a cell must
* be provided to store the information.
*/
vtkIdType FindCell(
double x[3], double tol2, vtkGenericCell* GenCell, double pcoords[3], double* weights) override;
/**
* Return a list of unique cell ids inside of a given bounding box. The
* user must provide the vtkIdList to populate. This method returns data
* only after the locator has been built.
*/
void FindCellsWithinBounds(double* bbox, vtkIdList* cells) override;
/**
* Given a finite line defined by the two points (p1,p2), return the list
* of unique cell ids in the buckets containing the line. It is possible
* that an empty cell list is returned. The user must provide the vtkIdList
* to populate. This method returns data only after the locator has been
* built.
* THIS METHOD IS NOT THREAD SAFE.
*/
void FindCellsAlongLine(
const double p1[3], const double p2[3], double tolerance, vtkIdList* cells) override;
//@{
/**
* Satisfy vtkLocator abstract interface.
*/
void FreeSearchStructure() override;
void BuildLocator() override;
virtual void BuildLocatorIfNeeded();
virtual void ForceBuildLocator();
virtual void BuildLocatorInternal();
void GenerateRepresentation(int level, vtkPolyData* pd) override;
//@}
protected:
vtkCellLocator();
~vtkCellLocator() override;
void GetBucketNeighbors(int ijk[3], int ndivs, int level);
void GetOverlappingBuckets(
const double x[3], int ijk[3], double dist, int prevMinLevel[3], int prevMaxLevel[3]);
void ClearCellHasBeenVisited();
void ClearCellHasBeenVisited(vtkIdType id);
double Distance2ToBucket(const double x[3], int nei[3]);
double Distance2ToBounds(const double x[3], double bounds[6]);
int NumberOfOctants; // number of octants in tree
double Bounds[6]; // bounding box root octant
int NumberOfParents; // number of parent octants
double H[3]; // width of leaf octant in x-y-z directions
int NumberOfDivisions; // number of "leaf" octant sub-divisions
vtkIdList** Tree; // octree
void MarkParents(void*, int, int, int, int, int);
void GetChildren(int idx, int level, int children[8]);
int GenerateIndex(int offset, int numDivs, int i, int j, int k, vtkIdType& idx);
void GenerateFace(
int face, int numDivs, int i, int j, int k, vtkPoints* pts, vtkCellArray* polys);
vtkNeighborCells* Buckets;
unsigned char* CellHasBeenVisited;
unsigned char QueryNumber;
void ComputeOctantBounds(int i, int j, int k);
double OctantBounds[6]; // the bounds of the current octant
int IsInOctantBounds(const double x[3], double tol = 0.0)
{
if (this->OctantBounds[0] - tol <= x[0] && x[0] <= this->OctantBounds[1] + tol &&
this->OctantBounds[2] - tol <= x[1] && x[1] <= this->OctantBounds[3] + tol &&
this->OctantBounds[4] - tol <= x[2] && x[2] <= this->OctantBounds[5] + tol)
{
return 1;
}
else
{
return 0;
}
}
private:
vtkCellLocator(const vtkCellLocator&) = delete;
void operator=(const vtkCellLocator&) = delete;
};
#endif