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/****************************************************************************
* 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. *
* *
****************************************************************************/
/****************************************************************************
History
****************************************************************************/
#ifndef __VCGLIB_SEGMENT2
#define __VCGLIB_SEGMENT2
#include <vcg/space/point2.h>
#include <vcg/space/line2.h>
#include <vcg/space/box2.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 Segment2
{
public:
/// The scalar type
typedef SegmentScalarType ScalarType;
/// The point type
typedef Point2<SegmentScalarType> PointType;
/// The point type
typedef Segment2<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
Segment2() {};
/// The (a,b) constructor
Segment2(const PointType &a, const PointType &b) { _p0=a; _p1=b; };
/// Operator to compare segments
inline bool operator == ( SegmentType const & p ) const
{ return _p0==p._p0 && _p1==p._p1; }
/// Operator to dispare segments
inline bool operator != ( SegmentType const & p ) const
{ return _p0!=p._p0 || _p1!=p._p1; }
/// initializes the segment with its extrema
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 Box2<ScalarType> BBox( ) const
{
Box2<ScalarType> t;
t.Add(_p0);
t.Add(_p1);
return t;
}
/// returns segment length
ScalarType Length()
{ return (_p0 - _p1).Norm(); }
/// returns segment length
ScalarType Length() const
{ return (_p0 - _p1).Norm(); }
/// return segment squared lenght
ScalarType SquaredLength()
{ return (_p0 - _p1).SquaredNorm(); }
/// flips: a-b becomes b-a
void Flip()
{ PointType t=_p0; _p0=_p1; _p1=t; }
/// importer for different line types
template <class Q>
inline void Import( const Segment2<Q> & b )
{ _p0.Import( b.P0() ); _p1.Import( b.P1() );
}
/// copy constructor (builds a new segment importing an existing one)
template <class Q>
static SegmentType Construct( const Segment2<Q> & b )
{ return SegmentType(PointType::Construct(b.P0()), PointType::Construct(b.P1()));}
//@{
/** @name Linearity for 3d segments (operators +, -, *, /) **/
inline SegmentType operator + ( SegmentType const & p) const
{return SegmentType( _p0+p.P0(), _p1+p.P1() );}
inline SegmentType operator - ( SegmentType const & p) const
{return SegmentType( _p0-p.P0(), _p1-p.P1() );}
inline SegmentType operator * ( const ScalarType s ) const
{return SegmentType( _p0*s, _p1*s );}
inline SegmentType operator / ( const ScalarType s ) const
{ScalarType s0=((ScalarType)1.0)/s; return SegmentType( _p0*s0, _p1*s0 );}
//@}
}; // end class definition
typedef Segment2<short> Segment2s;
typedef Segment2<int> Segment2i;
typedef Segment2<float> Segment2f;
typedef Segment2<double> Segment2d;
template <class ScalarType>
Point2<ScalarType> ClosestPoint( Segment2<ScalarType> s, const Point2<ScalarType> & p)
{
vcg::Line2<ScalarType, true> l;
l.Set(s.P0(),s.P1()-s.P0());
ScalarType t = l.Projection(p);
Point2<ScalarType> clos = l.P(t);
ScalarType lenght = s.Length();
if (t <= 0)
return s.P0();
else if (t >= lenght)
return s.P1();
else
return clos;
}
/*@}*/
} // end namespace
#endif
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