// -*- c++ -*-

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

  Program:   Visualization Toolkit
  Module:    vtkPointsProjectedHull.h
  Language:  C++
  Date:      $Date$
  Version:   $Revision$

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

// .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 <vtksnlGraphicsWin32Header.h>
#include <vtkObjectFactory.h>
#include <vtkSetGet.h>
#include <vtkPoints.h>


class VTK_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);
  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];
};
#endif


