Segment.h

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#ifndef _utl_Segment_h_
#define _utl_Segment_h_

#include <utl/Point.h>
#include <utl/Vector.h>


namespace utl {

  class Segment {
  public:
    Segment(const Point& b, const Point& e) :
      fBegin(b),
      fEnd(e),
      fDirection(e - b)
    {
      fLength = fDirection.GetMag();
      // Normalize.
      fDirection *= 1/fLength;
    }

    const Point& GetBegin() const { return fBegin; }

    const Point& GetEnd() const { return fEnd; }

    const Vector& GetDirection() const { return fDirection; }

    double GetLength() const { return fLength; }

  private:
    Point fBegin;
    Point fEnd;
    Vector fDirection;
    double fLength;
    /*
     * RFG 20090930
     * In the geometry package there's AxialVector, Vector and Point; and some derived objects
     * like Line and Plane. Since a Vector is not modified upon transalation, is not the right
     * choice to represent a segment between two points (like the track of a particle inside a
     * detector).
     * As seen, this class is pretty silly as itself, but seems the right choice instead of using
     * an std:pair (which one is the start, first or second?) or the two points separately.
     * Taking a look at preexisting classes it's seen:
     * - FdProfileReconstructor uses a std::vector<utl::Point>.
     * - TelescopeSimulatorKG::RayTrace::DrawTrack (const utl::Point &p1, const utl::Point &p2, int color) const.
     * - In atm::VMieModel, for instance, there are several methods that take two points.
     *
     * Up to now, as said, this class is a little silly, later on it can be extended with more operations or,
     * more likely, with proper non-member operators.
     */
  };

}


#endif