VTK-5.0.0/Graphics/vtkPointsProjectedHull.h

/*=========================================================================

  Program:   Visualization Toolkit
  Module:    $RCSfile: vtkPointsProjectedHull.h,v $

  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.
----------------------------------------------------------------------------*/

// .NAME vtkPointsProjectedHull - the convex hull of the orthogonal 
//    projection of the vtkPoints in the 3 coordinate directions
// .SECTION Description
//    a subclass of vtkPoints, it maintains the counter clockwise 
//    convex hull of the points (projected orthogonally in the 
//    three coordinate directions) and has a method to
//    test for intersection of that hull with an axis aligned
//    rectangle.  This is used for intersection tests of 3D volumes.

#ifndef __vtkPointsProjectedHull_h
#define __vtkPointsProjectedHull_h

#include "vtkPoints.h"

class VTK_GRAPHICS_EXPORT vtkPointsProjectedHull : public vtkPoints
{
    vtkTypeRevisionMacro(vtkPointsProjectedHull, vtkPoints);

public:
    void PrintSelf(ostream& os, vtkIndent indent);

    static vtkPointsProjectedHull *New();

    // Description:  Project the box R along the positive X axis and
    //   determine whether the resulting rectangle intersects the
    //   convex hull of the projection of the points along that axis.

    int RectangleIntersectionX(vtkPoints *R);

    // Description:  Determine whether the given rectangle intersects 
    //   the convex hull of the projection of the points along the
    //   positive X-axis.

    int RectangleIntersectionX(float ymin, float ymax, float zmin, float zmax);
    int RectangleIntersectionX(double ymin, double ymax, double zmin, double zmax);

    // Description:  Determine if a rectangle intersects the convex hull
    //   of the parallel projection along the Y axis of the points

    int RectangleIntersectionY(vtkPoints *R);

    // Description:  Determine whether the given rectangle intersects 
    //   the convex hull of the projection of the points along the
    //   positive Y-axis.

    int RectangleIntersectionY(float zmin, float zmax, float xmin, float xmax);
    int RectangleIntersectionY(double zmin, double zmax, double xmin, double xmax);

    // Description:  Determine if a rectangle intersects the convex hull
    //   of the parallel projection along the Z axis of the points

    int RectangleIntersectionZ(vtkPoints *R);

    // Description:  Determine whether the given rectangle intersects 
    //   the convex hull of the projection of the points along the
    //   positive Z-axis.

    int RectangleIntersectionZ(float xmin, float xmax, float ymin, float ymax);
    int RectangleIntersectionZ(double xmin, double xmax, double ymin, double ymax);

    // Description:
    //   Returns the coordinates (y,z) of the points in the convex hull 
    //   of the projection of the points down the positive x-axis.  pts has
    //   storage for len*2 values.
   
    int GetCCWHullX(float *pts, int len);
    int GetCCWHullX(double *pts, int len);

    // Description:
    //   Returns the coordinates (z, x) of the points in the convex hull 
    //   of the projection of the points down the positive y-axis.  pts has
    //   storage for len*2 values.

    int GetCCWHullY(float *pts, int len);
    int GetCCWHullY(double *pts, int len);

    // Description:
    //   Returns the coordinates (x, y) of the points in the convex hull 
    //   of the projection of the points down the positive z-axis.  pts has
    //   storage for len*2 values.

    int GetCCWHullZ(float *pts, int len);
    int GetCCWHullZ(double *pts, int len);

    // Description:
    //  Returns the number of points in the convex hull of the projection
    //  of the points down the positive x-axis

    int GetSizeCCWHullX();

    // Description:
    //  Returns the number of points in the convex hull of the projection
    //  of the points down the positive y-axis

    int GetSizeCCWHullY();

    // Description:
    //  Returns the number of points in the convex hull of the projection
    //  of the points down the positive z-axis

    int GetSizeCCWHullZ();

    void Initialize();
    void Reset(){this->Initialize();}

    // Description:
    //   Forces recalculation of convex hulls, use this if
    //   you delete/add points

    void Update();

protected:

    vtkPointsProjectedHull();
    ~vtkPointsProjectedHull();

private:

  int RectangleIntersection(double hmin, double hmax,
                            double vmin, double vmax, int direction);
  int GrahamScanAlgorithm(int direction);
  void GetPoints();
  int RectangleBoundingBoxIntersection(double hmin, double hmax,
                            double vmin, double vmax, int direction);
  int RectangleOutside(double hmin, double hmax,
                            double vmin, double vmax, int direction);

  int RectangleOutside1DPolygon(double hmin, double hmax,
                            double vmin, double vmax, int dir);

  void InitFlags();
  void ClearAllocations();


  static int RemoveExtras(double *pts, int n);
  static double Distance(double *p1, double *p2);
  static int PositionInHull(double *base, double *top, double *pt);
  static int OutsideLine(double hmin, double hmax,
           double vmin, double vmax, double *p0, double *p1, double *insidePt);
  static int OutsideHorizontalLine(double vmin, double vmax, 
           double *p0, double *p1, double *insidePt);
  static int OutsideVerticalLine(double hmin, double hmax, double *p0, 
           double *p1, double *insidePt);

  double *Pts;
  int Npts;
  vtkTimeStamp PtsTime;

  double *CCWHull[3];
  float HullBBox[3][4];
  int HullSize[3];
  vtkTimeStamp HullTime[3];

  vtkPointsProjectedHull(const vtkPointsProjectedHull&); // Not implemented
  void operator=(const vtkPointsProjectedHull&); // Not implemented
};
#endif