#ifndef _utl_GeometryUtilities_h_
#define _utl_GeometryUtilities_h_

/**
   \file
   Collection of geometry related utilities

   \author Lukas Nellen
   \author Darko Veberic
   \author Stefanie Falk
   \version $Id: GeometryUtilities.h 21217 2012-05-25 12:45:23Z darko $
   \date 30 Jan 2004
   \date 16 Jun 2006 Plane, Line
   \date 03 May 2012 RefEllipsoid, Line
*/

#include <utl/Line.h>
#include <utl/Plane.h>
#include <utl/Vector.h>
#include <vector>

static const char CVSId_utl_GeometryUtilities[] =
  "$Id: GeometryUtilities.h 21217 2012-05-25 12:45:23Z darko $";


namespace utl {

  class ReferenceEllipsoid;


  namespace GeometryUtilities {

    /*! Normalize angle to lie between -pi and pi
        \ingroup geometry
    */
    double NormalizeAngle(const double theAngle);

    // intersection

    /*! Compute the intersection between two planes.
        \ingroup geometry
    */
    Line Intersection(const Plane& p1, const Plane& p2);

    /*! Compute the intersection between a plane and a line.
        \ingroup geometry
    */
    Point Intersection(const Plane& plane, const Line& line);

    /*! Compute the intersection between a line and a plane.
        \ingroup geometry
    */
    inline Point Intersection(const Line& line, const Plane& plane)
    { return Intersection(plane, line); }

    /*! Compute the intersection between a line and an ellipsoid with some height
        \ingroup geometry
    */
    std::vector<Point> Intersection(const ReferenceEllipsoid&, const double height,
                                    const Line& line);

    // distance

    /*! Compute the distance between two lines.
        \ingroup geometry
    */
    double Distance(const Line& line1, const Line& line2);

    /*! Compute the distance between a point and a line.
        \ingroup geometry
    */
    double Distance(const Point& point, const Line& line);

    /*! Compute the distance between a line and a point.
        \ingroup geometry
    */
    inline double Distance(const Line& line, const Point& point)
    { return Distance(point, line); }

    /*! Compute the distance between a point and a plane.
        \ingroup geometry
    */
    inline double Distance(const Point& point, const Plane& plane)
    { return (point - plane.GetAnchor())*plane.GetNormal(); }

    /*! Compute the distance between a plane and a point.
        \ingroup geometry
    */
    inline double Distance(const Plane& plane, const Point& point)
    { return Distance(point, plane); }

    // projection

    /*! Compute the projection of a point on a plane.
        \ingroup geometry
    */
    inline Point PerpendicularProjection(const Point& point, const Plane& plane)
    { return point - Distance(point, plane)*plane.GetNormal(); }

    /*! Compute the projection of a point on a plane.
        \ingroup geometry
    */
    inline Point PerpendicularProjection(const Plane& plane, const Point& point)
    { return PerpendicularProjection(point, plane); }


  } // namespace GeometryUtilities

} // utl


#endif // _utl_GeometryUtilities_h_

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