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// Copyright (c) 2000
// Utrecht University (The Netherlands),
// ETH Zurich (Switzerland),
// INRIA Sophia-Antipolis (France),
// Max-Planck-Institute Saarbruecken (Germany),
// and Tel-Aviv University (Israel). All rights reserved.
//
// This file is part of CGAL (www.cgal.org); you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; either version 3 of the License,
// or (at your option) any later version.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL: svn+ssh://scm.gforge.inria.fr/svn/cgal/branches/next/Intersections_2/include/CGAL/Line_2_Iso_rectangle_2_intersection.h $
// $Id: Line_2_Iso_rectangle_2_intersection.h 67093 2012-01-13 11:22:39Z lrineau $
//
//
// Author(s) : Geert-Jan Giezeman
#ifndef CGAL_LINE_2_ISO_RECTANGLE_2_INTERSECTION_H
#define CGAL_LINE_2_ISO_RECTANGLE_2_INTERSECTION_H
#include <CGAL/Line_2.h>
#include <CGAL/Iso_rectangle_2.h>
#include <CGAL/Line_2.h>
#include <CGAL/kernel_assertions.h>
#include <CGAL/number_utils.h>
#include <CGAL/Object.h>
namespace CGAL {
namespace internal {
template <class K>
class Line_2_Iso_rectangle_2_pair {
public:
enum Intersection_results {NO_INTERSECTION, POINT, SEGMENT};
Line_2_Iso_rectangle_2_pair(typename K::Line_2 const *line,
typename K::Iso_rectangle_2 const *iso)
: _known(false),
_ref_point(line->point()),
_dir(line->direction().to_vector()),
_isomin((iso->min)()),
_isomax((iso->max)()) {}
Intersection_results intersection_type() const;
typename K::Point_2 intersection_point() const;
typename K::Segment_2 intersection_segment() const;
protected:
mutable bool _known;
mutable Intersection_results _result;
mutable typename K::FT _min, _max;
typename K::Point_2 _ref_point;
typename K::Vector_2 _dir;
typename K::Point_2 _isomin;
typename K::Point_2 _isomax;
};
template <class K>
inline bool do_intersect(const typename K::Line_2 &p1,
const typename K::Iso_rectangle_2 &p2,
const K&)
{
typedef Line_2_Iso_rectangle_2_pair<K> pair_t;
pair_t pair(&p1, &p2);
return pair.intersection_type() != pair_t::NO_INTERSECTION;
}
template <class K>
inline bool do_intersect(const typename K::Iso_rectangle_2 &p2,
const typename K::Line_2 &p1,
const K& k)
{
return internal::do_intersect(p1, p2, k);
}
template <class K>
typename Line_2_Iso_rectangle_2_pair<K>::Intersection_results
Line_2_Iso_rectangle_2_pair<K>::intersection_type() const
{
typedef typename K::Line_2 line_t;
if (_known)
return _result;
// The non const this pointer is used to cast away const.
_known = true;
typedef typename K::FT FT;
typedef typename K::RT RT;
bool all_values = true;
typename K::Construct_cartesian_const_iterator_2 construct_cccit;
typename K::Cartesian_const_iterator_2 ref_point_it = construct_cccit(_ref_point);
typename K::Cartesian_const_iterator_2 end = construct_cccit(_ref_point, 0);
typename K::Cartesian_const_iterator_2 isomin_it = construct_cccit(_isomin);
typename K::Cartesian_const_iterator_2 isomax_it = construct_cccit(_isomax);
for (unsigned int i=0; ref_point_it != end; ++i, ++ref_point_it, ++isomin_it, ++isomax_it) {
if (_dir.homogeneous(i) == RT(0)) {
if (*ref_point_it < *isomin_it) {
_result = NO_INTERSECTION;
return NO_INTERSECTION;
}
if (*ref_point_it > *isomax_it) {
_result = NO_INTERSECTION;
return NO_INTERSECTION;
}
} else {
FT newmin, newmax;
if (_dir.homogeneous(i) > RT(0)) {
newmin = (*isomin_it - *ref_point_it) /
_dir.cartesian(i);
newmax = (*isomax_it - *ref_point_it) /
_dir.cartesian(i);
} else {
newmin = (*isomax_it - *ref_point_it) /
_dir.cartesian(i);
newmax = (*isomin_it - *ref_point_it) /
_dir.cartesian(i);
}
if (all_values) {
_min = newmin;
_max = newmax;
} else {
if (newmin > _min)
_min = newmin;
if (newmax < _max)
_max = newmax;
if (_max < _min) {
_result = NO_INTERSECTION;
return NO_INTERSECTION;
}
}
all_values = false;
}
}
CGAL_kernel_assertion(!all_values);
if (_max == _min) {
_result = POINT;
return POINT;
}
_result = SEGMENT;
return SEGMENT;
}
template <class K>
typename K::Point_2
Line_2_Iso_rectangle_2_pair<K>::
intersection_point() const
{
typename K::Construct_translated_point_2 translated_point;
typename K::Construct_scaled_vector_2 construct_scaled_vector;
if (!_known)
intersection_type();
CGAL_kernel_assertion(_result == POINT);
return translated_point(_ref_point, construct_scaled_vector(_dir, _min));
}
template <class K>
typename K::Segment_2
Line_2_Iso_rectangle_2_pair<K>::
intersection_segment() const
{
typename K::Construct_segment_2 construct_segment_2;
typename K::Construct_translated_point_2 translated_point;
typename K::Construct_scaled_vector_2 construct_scaled_vector;
if (!_known)
intersection_type();
CGAL_kernel_assertion(_result == SEGMENT);
return construct_segment_2(translated_point(_ref_point, construct_scaled_vector(_dir,_min)),
translated_point(_ref_point, construct_scaled_vector(_dir,_max)));
}
template <class K>
Object
intersection(const typename K::Line_2 &line,
const typename K::Iso_rectangle_2 &iso,
const K&)
{
typename K::Construct_object_2 construct_object;
typedef Line_2_Iso_rectangle_2_pair<K> is_t;
is_t ispair(&line, &iso);
switch (ispair.intersection_type()) {
case is_t::NO_INTERSECTION:
default:
return Object();
case is_t::POINT:
return construct_object(ispair.intersection_point());
case is_t::SEGMENT:
return construct_object(ispair.intersection_segment());
}
}
template <class K>
inline
Object
intersection(const typename K::Iso_rectangle_2 &iso,
const typename K::Line_2 &line,
const K& k)
{
return internal::intersection(line, iso, k);
}
} // namespace internal
template <class K>
inline bool do_intersect(
const Line_2<K> &p1,
const Iso_rectangle_2<K> &p2)
{
typedef typename K::Do_intersect_2 Do_intersect;
return Do_intersect()(p1, p2);
}
template <class K>
inline bool do_intersect(
const Iso_rectangle_2<K> &p1,
const Line_2<K> &p2)
{
typedef typename K::Do_intersect_2 Do_intersect;
return Do_intersect()(p2, p1);
}
template <class K>
Object
intersection(const Line_2<K> &line, const Iso_rectangle_2<K> &iso)
{
typedef typename K::Intersect_2 Intersect;
return Intersect()(line, iso);
}
template <class K>
inline Object
intersection(const Iso_rectangle_2<K> &iso, const Line_2<K> &line)
{
typedef typename K::Intersect_2 Intersect;
return Intersect()(line, iso);
}
} //namespace CGAL
#endif
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