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/*
* Infinite Straight Line
*
* Copyright 2008 Marco Cecchetti <mrcekets at gmail.com>
* Nathan Hurst
*
* 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.
*/
#include <2geom/line.h>
#include <algorithm>
namespace Geom
{
namespace detail
{
inline
OptCrossing intersection_impl(Point const& V1, Point const O1,
Point const& V2, Point const O2 )
{
double detV1V2 = V1[X] * V2[Y] - V2[X] * V1[Y];
if (are_near(detV1V2, 0)) return OptCrossing();
Point B = O2 - O1;
double detBV2 = B[X] * V2[Y] - V2[X] * B[Y];
double detV1B = B[X] * V1[Y] - V1[X] * B[Y];
double inv_detV1V2 = 1 / detV1V2;
Crossing c;
c.ta = detBV2 * inv_detV1V2;
c.tb = detV1B * inv_detV1V2;
// std::cerr << "ta = " << solution.ta << std::endl;
// std::cerr << "tb = " << solution.tb << std::endl;
return OptCrossing(c);
}
OptCrossing intersection_impl(Ray const& r1, Line const& l2, unsigned int i)
{
OptCrossing crossing =
intersection_impl(r1.versor(), r1.origin(),
l2.versor(), l2.origin() );
if (crossing)
{
if (crossing->ta < 0)
{
return OptCrossing();
}
else
{
if (i != 0)
{
std::swap(crossing->ta, crossing->tb);
}
return crossing;
}
}
if (are_near(r1.origin(), l2))
{
THROW_INFINITESOLUTIONS();
}
else
{
return OptCrossing();
}
}
OptCrossing intersection_impl( LineSegment const& ls1,
Line const& l2,
unsigned int i )
{
OptCrossing crossing =
intersection_impl(ls1.finalPoint() - ls1.initialPoint(),
ls1.initialPoint(),
l2.versor(),
l2.origin() );
if (crossing)
{
if ( crossing->getTime(0) < 0
|| crossing->getTime(0) > 1 )
{
return OptCrossing();
}
else
{
if (i != 0)
{
std::swap((*crossing).ta, (*crossing).tb);
}
return crossing;
}
}
if (are_near(ls1.initialPoint(), l2))
{
THROW_INFINITESOLUTIONS();
}
else
{
return OptCrossing();
}
}
OptCrossing intersection_impl( LineSegment const& ls1,
Ray const& r2,
unsigned int i )
{
Point direction = ls1.finalPoint() - ls1.initialPoint();
OptCrossing crossing =
intersection_impl( direction,
ls1.initialPoint(),
r2.versor(),
r2.origin() );
if (crossing)
{
if ( crossing->getTime(0) < 0
|| crossing->getTime(0) > 1
|| crossing->getTime(1) < 0 )
{
return OptCrossing();
}
else
{
if (i != 0)
{
std::swap(crossing->ta, crossing->tb);
}
return crossing;
}
}
if ( are_near(r2.origin(), ls1) )
{
bool eqvs = (dot(direction, r2.versor()) > 0);
if ( are_near(ls1.initialPoint(), r2.origin()) && !eqvs )
{
crossing->ta = crossing->tb = 0;
return crossing;
}
else if ( are_near(ls1.finalPoint(), r2.origin()) && eqvs )
{
if (i == 0)
{
crossing->ta = 1;
crossing->tb = 0;
}
else
{
crossing->ta = 0;
crossing->tb = 1;
}
return crossing;
}
else
{
THROW_INFINITESOLUTIONS();
}
}
else if ( are_near(ls1.initialPoint(), r2) )
{
THROW_INFINITESOLUTIONS();
}
else
{
OptCrossing no_crossing;
return no_crossing;
}
}
} // end namespace detail
OptCrossing intersection(Line const& l1, Line const& l2)
{
OptCrossing crossing =
detail::intersection_impl( l1.versor(), l1.origin(),
l2.versor(), l2.origin() );
if (crossing)
{
return crossing;
}
if (are_near(l1.origin(), l2))
{
THROW_INFINITESOLUTIONS();
}
else
{
return crossing;
}
}
OptCrossing intersection(Ray const& r1, Ray const& r2)
{
OptCrossing crossing =
detail::intersection_impl( r1.versor(), r1.origin(),
r2.versor(), r2.origin() );
if (crossing)
{
if ( crossing->ta < 0
|| crossing->tb < 0 )
{
OptCrossing no_crossing;
return no_crossing;
}
else
{
return crossing;
}
}
if ( are_near(r1.origin(), r2) || are_near(r2.origin(), r1) )
{
if ( are_near(r1.origin(), r2.origin())
&& !are_near(r1.versor(), r2.versor()) )
{
crossing->ta = crossing->tb = 0;
return crossing;
}
else
{
THROW_INFINITESOLUTIONS();
}
}
else
{
OptCrossing no_crossing;
return no_crossing;
}
}
OptCrossing intersection( LineSegment const& ls1, LineSegment const& ls2 )
{
Point direction1 = ls1.finalPoint() - ls1.initialPoint();
Point direction2 = ls2.finalPoint() - ls2.initialPoint();
OptCrossing crossing =
detail::intersection_impl( direction1,
ls1.initialPoint(),
direction2,
ls2.initialPoint() );
if (crossing)
{
if ( crossing->getTime(0) < 0
|| crossing->getTime(0) > 1
|| crossing->getTime(1) < 0
|| crossing->getTime(1) > 1 )
{
OptCrossing no_crossing;
return no_crossing;
}
else
{
return crossing;
}
}
bool eqvs = (dot(direction1, direction2) > 0);
if ( are_near(ls2.initialPoint(), ls1) )
{
if ( are_near(ls1.initialPoint(), ls2.initialPoint()) && !eqvs )
{
crossing->ta = crossing->tb = 0;
return crossing;
}
else if ( are_near(ls1.finalPoint(), ls2.initialPoint()) && eqvs )
{
crossing->ta = 1;
crossing->tb = 0;
return crossing;
}
else
{
THROW_INFINITESOLUTIONS();
}
}
else if ( are_near(ls2.finalPoint(), ls1) )
{
if ( are_near(ls1.finalPoint(), ls2.finalPoint()) && !eqvs )
{
crossing->ta = crossing->tb = 1;
return crossing;
}
else if ( are_near(ls1.initialPoint(), ls2.finalPoint()) && eqvs )
{
crossing->ta = 0;
crossing->tb = 1;
return crossing;
}
else
{
THROW_INFINITESOLUTIONS();
}
}
else
{
OptCrossing no_crossing;
return no_crossing;
}
}
Line make_angle_bisector_line(Line const& l1, Line const& l2)
{
OptCrossing crossing;
try
{
crossing = intersection(l1, l2);
}
catch(InfiniteSolutions e)
{
return l1;
}
if (!crossing)
{
THROW_RANGEERROR("passed lines are parallel");
}
Point O = l1.pointAt(crossing->ta);
Point A = l1.pointAt(crossing->ta + 1);
double angle = angle_between(l1.versor(), l2.versor());
Point B = (angle > 0) ? l2.pointAt(crossing->tb + 1)
: l2.pointAt(crossing->tb - 1);
return make_angle_bisector_line(A, O, B);
}
} // end namespace Geom
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(substatement-open . 0))
indent-tabs-mode:nil
c-brace-offset:0
fill-column:99
End:
vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
*/
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