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/*=========================================================================
Program: Visualization Toolkit
Module: vtkPlanesIntersection.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.
=========================================================================*/
/*----------------------------------------------------------------------------
Copyright (c) Sandia Corporation
See Copyright.txt or http://www.paraview.org/HTML/Copyright.html for details.
----------------------------------------------------------------------------*/
/**
* @class vtkPlanesIntersection
* @brief A vtkPlanesIntersection object is a
* vtkPlanes object that can compute whether the arbitrary convex region
* bounded by it's planes intersects an axis-aligned box.
*
*
* A subclass of vtkPlanes, this class determines whether it
* intersects an axis aligned box. This is motivated by the
* need to intersect the axis aligned region of a spacial
* decomposition of volume data with various other regions.
* It uses the algorithm from Graphics Gems IV, page 81.
*
* @par Caveat:
* An instance of vtkPlanes can be redefined by changing the planes,
* but this subclass then will not know if the region vertices are
* up to date. (Region vertices can be specified in SetRegionVertices
* or computed by the subclass.) So Delete and recreate if you want
* to change the set of planes.
*
*/
#ifndef vtkPlanesIntersection_h
#define vtkPlanesIntersection_h
#include "vtkCommonDataModelModule.h" // For export macro
#include "vtkPlanes.h"
class vtkPoints;
class vtkPointsProjectedHull;
class vtkCell;
class VTKCOMMONDATAMODEL_EXPORT vtkPlanesIntersection : public vtkPlanes
{
vtkTypeMacro(vtkPlanesIntersection, vtkPlanes);
public:
void PrintSelf(ostream& os, vtkIndent indent) override;
static vtkPlanesIntersection* New();
/**
* It helps if you know the vertices of the convex region.
* If you don't, we will calculate them. Region vertices
* are 3-tuples.
*/
void SetRegionVertices(vtkPoints* pts);
void SetRegionVertices(double* v, int nvertices);
int GetNumberOfRegionVertices();
// Retained for backward compatibility
int GetNumRegionVertices() { return this->GetNumberOfRegionVertices(); }
int GetRegionVertices(double* v, int nvertices);
/**
* Return 1 if the axis aligned box defined by R intersects
* the region defined by the planes, or 0 otherwise.
*/
int IntersectsRegion(vtkPoints* R);
/**
* A convenience function provided by this class, returns
* 1 if the polygon defined in pts intersects the bounding
* box defined in bounds, 0 otherwise.
* The points must define a planar polygon.
*/
static int PolygonIntersectsBBox(double bounds[6], vtkPoints* pts);
/**
* Another convenience function provided by this class, returns
* the vtkPlanesIntersection object representing a 3D
* cell. The point IDs for each face must be given in
* counter-clockwise order from the outside of the cell.
*/
static vtkPlanesIntersection* Convert3DCell(vtkCell* cell);
protected:
static void ComputeNormal(double* p1, double* p2, double* p3, double normal[3]);
static double EvaluatePlaneEquation(double* x, double* p);
static void PlaneEquation(double* n, double* x, double* p);
static int GoodNormal(double* n);
static int Invert3x3(double M[3][3]);
vtkPlanesIntersection();
~vtkPlanesIntersection() override;
private:
int IntersectsBoundingBox(vtkPoints* R);
int EnclosesBoundingBox(vtkPoints* R);
int EvaluateFacePlane(int plane, vtkPoints* R);
int IntersectsProjection(vtkPoints* R, int direction);
void SetPlaneEquations();
void ComputeRegionVertices();
void planesMatrix(int p1, int p2, int p3, double M[3][3]) const;
int duplicate(double testv[3]) const;
void planesRHS(int p1, int p2, int p3, double r[3]) const;
int outsideRegion(double v[3]);
// plane equations
double* Planes;
// vertices of convex regions enclosed by the planes, also
// the ccw hull of that region projected in 3 orthog. directions
vtkPointsProjectedHull* RegionPts;
vtkPlanesIntersection(const vtkPlanesIntersection&) = delete;
void operator=(const vtkPlanesIntersection&) = delete;
};
#endif