nearest-point.h revision 8001ba81cb851b38d86650a2fef5817facffb763
/*
* nearest point routines for D2<SBasis> and Piecewise<D2<SBasis>>
*
*
* Authors:
*
* Marco Cecchetti <mrcekets at gmail.com>
*
* Copyright 2007-2008 authors
*
* This library is free software; you can redistribute it and/or
* modify it either under the terms of the GNU Lesser General Public
* License version 2.1 as published by the Free Software Foundation
* (the "LGPL") or, at your option, under the terms of the Mozilla
* Public License Version 1.1 (the "MPL"). If you do not alter this
* notice, a recipient may use your version of this file under either
* the MPL or the LGPL.
*
* You should have received a copy of the LGPL along with this library
* in the file COPYING-LGPL-2.1; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
* You should have received a copy of the MPL along with this library
* in the file COPYING-MPL-1.1
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
* OF ANY KIND, either express or implied. See the LGPL or the MPL for
* the specific language governing rights and limitations.
*/
#ifndef _NEAREST_POINT_H_
#define _NEAREST_POINT_H_
#include <vector>
#include <2geom/d2.h>
#include <2geom/piecewise.h>
#include <2geom/exception.h>
namespace Geom
{
/*
* Given a line L specified by a point A and direction vector v,
* return the point on L nearest to p. Note that the returned value
* is with respect to the _normalized_ direction of v!
*/
inline double nearest_point(Point const &p, Point const &A, Point const &v)
{
Point d(p - A);
return d[0] * v[0] + d[1] * v[1];
}
////////////////////////////////////////////////////////////////////////////////
// D2<SBasis> versions
/*
* Return the parameter t of a nearest point on the portion of the curve "c",
* related to the interval [from, to], to the point "p".
* The needed curve derivative "dc" is passed as parameter.
* The function return the first nearest point to "p" that is found.
*/
double nearest_point( Point const& p,
D2<SBasis> const& c, D2<SBasis> const& dc,
double from = 0, double to = 1 );
inline
double nearest_point( Point const& p,
D2<SBasis> const& c,
double from = 0, double to = 1 )
{
return nearest_point(p, c, Geom::derivative(c), from, to);
}
/*
* Return the parameters t of all the nearest points on the portion of
* the curve "c", related to the interval [from, to], to the point "p".
* The needed curve derivative "dc" is passed as parameter.
*/
std::vector<double>
all_nearest_points( Point const& p,
D2<SBasis> const& c, D2<SBasis> const& dc,
double from = 0, double to = 1 );
inline
std::vector<double>
all_nearest_points( Point const& p,
D2<SBasis> const& c,
double from = 0, double to = 1 )
{
return all_nearest_points(p, c, Geom::derivative(c), from, to);
}
////////////////////////////////////////////////////////////////////////////////
// Piecewise< D2<SBasis> > versions
double nearest_point( Point const& p,
Piecewise< D2<SBasis> > const& c,
double from, double to );
inline
double nearest_point( Point const& p, Piecewise< D2<SBasis> > const& c )
{
return nearest_point(p, c, c.cuts[0], c.cuts[c.size()]);
}
std::vector<double>
all_nearest_points( Point const& p,
Piecewise< D2<SBasis> > const& c,
double from, double to );
inline
std::vector<double>
all_nearest_points( Point const& p, Piecewise< D2<SBasis> > const& c )
{
return all_nearest_points(p, c, c.cuts[0], c.cuts[c.size()]);
}
} // end namespace Geom
#endif /*_NEAREST_POINT_H_*/