/****************************************************************************
* VCGLib                                                            o o     *
* Visual and Computer Graphics Library                            o     o   *
*                                                                _   O  _   *
* Copyright(C) 2004                                                \/)\/    *
* Visual Computing Lab                                            /\/|      *
* ISTI - Italian National Research Council                           |      *
*                                                                    \      *
* All rights reserved.                                                      *
*                                                                           *
* This program is free software; you can redistribute it and/or modify      *   
* it under the terms of the GNU General Public License as published by      *
* the Free Software Foundation; either version 2 of the License, or         *
* (at your option) any later version.                                       *
*                                                                           *
* This program is distributed in the hope that it will be useful,           *
* but WITHOUT ANY WARRANTY; without even the implied warranty of            *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the             *
* GNU General Public License (http://www.gnu.org/licenses/gpl.txt)          *
* for more details.                                                         *
*                                                                           *
****************************************************************************/
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#ifndef __VCGLIB_SEGMENT3
#define __VCGLIB_SEGMENT3

#include <vcg/space/point3.h>
#include <vcg/space/box3.h>

namespace vcg {

/** \addtogroup space */
/*@{*/
/** 
Templated class for 3D segment.
  This is the class for a segment in 3D space. A Segment is stored just as its two extrema (Point3).
	@param SegmentScalarType (template parameter) Specifies the type of scalar used to represent coords.
*/
template <class SegmentScalarType >
class Segment3
{
public: 

	/// The scalar type
	typedef SegmentScalarType ScalarType;

	/// The point type
	typedef Point3<SegmentScalarType> PointType;

	/// The point type
	typedef Segment3<SegmentScalarType> SegmentType;

private:

	/// _extrema
	PointType _p0,_p1;

public:

		/// Members to access either extrema
  inline const PointType &P0() const { return _p0; } 
  inline const PointType &P1() const { return _p1; } 
  inline PointType &P0() { return _p0; } 
  inline PointType &P1() { return _p1; } 
		/// The empty constructor
	Segment3() {};
		/// The (a,b) constructor
	SegmentType(const PointType &a, const PointType &b) { _p0=a; _p1=b; };
		/// Operator to compare two bounding box
	inline bool operator == ( SegmentType const & p ) const
	{	return _p0==p._p0 && _p1==p._p1; }
		/// Operator to dispare two bounding box
	inline bool operator != ( SegmentType const & p ) const
	{	return _p0!=p._p0 || _p1!=p._p1; }
		/// initializes the bounding box
	void Set( const PointType &a, const PointType &b)
	{	_p0=a; _p1=b;}
	  /// calculates the point of parameter t on the segment.
	  /// if t is in [0..1] returned point is inside the segment
	inline PointType P( const ScalarType t ) const
	{ return _p0 + (_p1 - _p0) * t; }
	  /// return the middle point
	inline PointType MidPoint( ) const
	{ return ( _p0 +  _p1) / ScalarType(2.0) ; }
	  /// return the bounding box
	inline Box3<ScalarType> BBox( ) const
	{ Box3<ScalarType> t; 
	  if (_p0[0]<_p1[0]) { t.min[0]=_p0[0];t.max[0]=_p1[0];} else { t.min[0]=_p1[0];t.max[0]=_p0[0];}
		if (_p0[1]<_p1[1]) { t.min[1]=_p0[1];t.max[1]=_p1[1];} else { t.min[1]=_p1[1];t.max[1]=_p0[1];}
	  if (_p0[2]<_p1[2]) { t.min[2]=_p0[2];t.max[2]=_p1[2];} else { t.min[2]=_p1[2];t.max[2]=_p0[2];}
	  return t; }
		/// return lenght
	SegmentType &Length()
	{ return (_p0 - _p1).Norm(); }
		/// return squared lenght
	SegmentType &SquaredLength()
	{ return (_p0 - _p1).SquaredNorm(); }
	  /// flips: a-b becomes b-a
	void Flip()
	{ PointType t=_p0; _p0=_p1; _p1=t; }
	template <class Q>
	  /// importer for different line types
	inline void Import( const Segment3<Q> & b )
	{ _p0.Import( b._p0);	_p1.Import( b._p1);
	}

}; // end class definition



typedef Segment3<short>  Segment3s;
typedef Segment3<int>	   Segment3i;
typedef Segment3<float>  Segment3f;
typedef Segment3<double> Segment3d;


/*@}*/

} // end namespace
#endif