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cgal/Packages/Intersections_2/web/straight_2.fw

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@i cgal_util.fwi
@$@<2D Straight declaration@>==@{
CGAL_BEGIN_NAMESPACE
class Straight_2_base_ {
public:
enum states {EMPTY, POINT, SEGMENT, RAY, LINE};
enum bound_states {NO_UNBOUNDED=0, MIN_UNBOUNDED=1, MAX_UNBOUNDED=2,
BOTH_UNBOUNDED = 3, LINE_EMPTY = 4};
protected:
Straight_2_base_() ;
int main_dir_; // support_ is x or y directed (0/1).
int dir_sign_; // sign of main direction coord.
unsigned int bound_state_; // 0, 1, 2, 3, 4.
public:
inline unsigned int bound_state() const {return bound_state_;}
};
template <class R>
class Straight_2_: public Straight_2_base_ {
public:
Straight_2_() ;
Straight_2_(Point_2<R> const &point) ;
Straight_2_(Line_2<R> const &line) ;
Straight_2_(Ray_2<R> const &ray) ;
Straight_2_(Ray_2<R> const &ray,bool cooriented) ;
Straight_2_(Segment_2<R> const &seg) ;
~Straight_2_() {}
void cut_right_off(Line_2<R> const & cutter) ;
int collinear_order(Point_2<R> const & p1,
Point_2<R> const &p2) const ;
void current(Line_2<R> &line) const;
void current(Ray_2<R> &ray) const;
void current(Segment_2<R> &seg) const;
void current(Point_2<R> &point) const;
states current_state() const;
bool operator==(const Straight_2_<R>&) const;
bool operator!=(const Straight_2_<R>&other) const
{ return !(*this == other);}
protected:
Line_2<R> support_; // The supporting line.
Point_2<R> min_;
Point_2<R> max_;
};
CGAL_END_NAMESPACE
@<2D Straight implementation@>
@}
@$@<2D Straight implementation@>==@{
#include <CGAL/Line_2_Line_2_intersection.h>
CGAL_BEGIN_NAMESPACE
inline
Straight_2_base_::
Straight_2_base_()
{
bound_state_ = LINE_EMPTY;
}
template <class R>
Straight_2_base_::states
Straight_2_<R>::
current_state() const
{
switch (bound_state_) {
case BOTH_UNBOUNDED:
return LINE;
case MIN_UNBOUNDED:
case MAX_UNBOUNDED:
return RAY;
case NO_UNBOUNDED:
return (collinear_order(min_, max_) == 0) ? POINT : SEGMENT;
case LINE_EMPTY:
default:
return EMPTY;
}
}
template <class R>
Straight_2_<R>::
Straight_2_()
{
bound_state_ = LINE_EMPTY;
}
template <class R>
Straight_2_<R>::
Straight_2_(Line_2<R> const &line)
{
support_ = line;
Vector_2<R> const &dir = support_.direction().to_vector();
main_dir_ = (CGAL_NTS abs(dir.x()) > CGAL_NTS abs(dir.y()) ) ? 0 : 1;
dir_sign_ =
CGAL_NTS sign(support_.direction().to_vector().cartesian(main_dir_));
bound_state_ = BOTH_UNBOUNDED;
}
template <class R>
Straight_2_<R>::
Straight_2_(Point_2<R> const &point)
{
support_ = Line_2<R>(point, Direction_2<R>(R::RT(1),R::RT(0)));
main_dir_ = 0;
dir_sign_ = 1;
bound_state_ = NO_UNBOUNDED;
min_ = point;
max_ = point;
}
template <class R>
Straight_2_<R>::
Straight_2_(Ray_2<R> const &ray)
{
support_ = ray.supporting_line();
Vector_2<R> const &dir = ray.direction().to_vector();
// main_dir_ = (CGAL_NTS abs(dir.hx()) > CGAL_NTS abs(dir.hy()) ) ? 0 : 1;
main_dir_ = (CGAL_NTS abs(dir.x()) > CGAL_NTS abs(dir.y()) ) ? 0 : 1;
dir_sign_ =
CGAL_NTS sign(support_.direction().to_vector().cartesian(main_dir_));
bound_state_ = MAX_UNBOUNDED;
min_ = ray.start();
}
template <class R>
Straight_2_<R>::
Straight_2_(Ray_2<R> const &ray_,bool cooriented)
{
Ray_2<R> const &ray = cooriented ? ray_ : ray_.opposite();
support_ = ray.supporting_line();
/* the supporting line is cooriented with the input ray iff
cooriented is true */
Vector_2<R> const &dir = ray.direction().to_vector();
// main_dir_ = (CGAL_NTS abs(dir.hx()) > CGAL_NTS abs(dir.hy()) ) ? 0 : 1;
main_dir_ = (CGAL_NTS abs(dir.x()) > CGAL_NTS abs(dir.y()) ) ? 0 : 1;
dir_sign_ =
CGAL_NTS sign(support_.direction().to_vector().cartesian(main_dir_));
if (cooriented)
{
bound_state_ = MAX_UNBOUNDED;
min_ = ray.start();
}
else
{
bound_state_ = MIN_UNBOUNDED;
max_ = ray.start();
}
}
template <class R>
Straight_2_<R>::
Straight_2_(Segment_2<R> const &seg)
{
support_ = seg.supporting_line();
Vector_2<R> const &dir = support_.direction().to_vector();
main_dir_ = (CGAL_NTS abs(dir.x()) > CGAL_NTS abs(dir.y()) ) ? 0 : 1;
dir_sign_ =
CGAL_NTS sign(support_.direction().to_vector().cartesian(main_dir_));
bound_state_ = NO_UNBOUNDED;
min_ = seg.start();
max_ = seg.end();
}
template <class R>
void
Straight_2_<R>::
current(Line_2<R> &line) const
{
CGAL_kernel_assertion(bound_state_ == BOTH_UNBOUNDED);
line = support_;
}
template <class R>
void
Straight_2_<R>::
current(Ray_2<R> &ray) const
{
CGAL_kernel_assertion(bound_state_ == MIN_UNBOUNDED
|| bound_state_ == MAX_UNBOUNDED);
if (bound_state_ == MIN_UNBOUNDED) {
ray = Ray_2<R>(max_, -support_.direction());
} else {
ray = Ray_2<R>(min_, support_.direction());
}
}
template <class R>
void
Straight_2_<R>::
current(Segment_2<R> &seg) const
{
CGAL_kernel_assertion(bound_state_ == NO_UNBOUNDED
&& collinear_order(min_, max_) != 0);
seg = Segment_2<R>(min_, max_);
}
template <class R>
void
Straight_2_<R>::
current(Point_2<R> &pt) const
{
CGAL_kernel_assertion(bound_state_ == NO_UNBOUNDED
&& collinear_order(min_, max_) == 0);
pt = min_;
}
template <class R>
bool Straight_2_<R>::operator==(const Straight_2_<R>& s) const
{
typedef Straight_2_<R> Straight_2;
// enum bound_states {NO_UNBOUNDED=0, MIN_UNBOUNDED=1, MAX_UNBOUNDED=2,
// BOTH_UNBOUNDED = 3, LINE_EMPTY = 4};
if (bound_state_!=s.bound_state()) return false;
if (bound_state_==Straight_2::LINE_EMPTY) return true; // empty
if (support_!=s.support_)
return false; // on different lines, even if both are points.
switch (bound_state_)
{
case Straight_2::NO_UNBOUNDED:
return min_==s.min_ && max_==s.max_;
case Straight_2::MAX_UNBOUNDED:
return min_==s.min_;
case Straight_2::MIN_UNBOUNDED:
return max_==s.max_;
case Straight_2::BOTH_UNBOUNDED:
return true;
}
return false;
}
/*
template <class R>
R::FT
cross(Vector_2<R> const &vec1, Vector_2<R> const &vec2)
{
(vec1.hx() * vec2.hy() - vec1.hy() * vec2.hx()) / (vec1.hw()*vec2.hw());
}
*/
#if 0 // #ifdef CGAL_CARTESIAN_H
template <class FT>
FT
cross(Vector_2< Cartesian<FT> > const &vec1,
Vector_2< Cartesian<FT> > const &vec2)
{
return vec1.x() * vec2.y() - vec1.y() * vec2.x();
}
template <class R>
int
sign_of_cross(Direction_2<R> const &dir1,
Direction_2<R> const &dir2)
{
return CGAL_NTS sign(cross(dir1.to_vector(), dir2.to_vector()));
}
#endif
CGAL_END_NAMESPACE
#include <CGAL/squared_distance_utils.h>
CGAL_BEGIN_NAMESPACE
template <class R>
int
sign_of_cross(Direction_2<R> const &dir1,
Direction_2<R> const &dir2)
{
int result;
switch(orientation(dir1.to_vector(), dir2.to_vector())) {
case COUNTERCLOCKWISE:
result = 1;
break;
case CLOCKWISE:
result = -1;
break;
case COLLINEAR:
result = 0;
break;
}
return result;
}
template <class R>
void
Straight_2_<R>::
cut_right_off(Line_2<R> const & cutter)
// cut off any part of this straight that is to the right of the cutter.
{
if (bound_state_ == LINE_EMPTY)
return;
Point_2<R> ispoint;
bool new_point;
Line_2_Line_2_pair<R> pair(&support_, &cutter);
switch (pair.intersection_type()) {
case Line_2_Line_2_pair<R>::NO:
if (cutter.has_on_negative_side(support_.point()))
bound_state_ = LINE_EMPTY;
break;
case Line_2_Line_2_pair<R>::LINE:
break;
case Line_2_Line_2_pair<R>::POINT:
pair.intersection(ispoint);
new_point = false;
switch (sign_of_cross(support_.direction(), cutter.direction())) {
case -1: // new minimum.
if (bound_state_ & MIN_UNBOUNDED) {
new_point = true;
bound_state_ ^= MIN_UNBOUNDED; // exclusive or removes flag.
} else {
if (collinear_order(ispoint, min_) == -1)
new_point = true;
}
if (new_point) {
if (!(bound_state_ & MAX_UNBOUNDED)
&& collinear_order(ispoint, max_) == -1)
bound_state_ = LINE_EMPTY;
else
min_ = ispoint;
}
break;
case 0: // should not happen
CGAL_kernel_warning_msg(false, "Internal CGAL error.");
break;
case 1: // new maximum
if (bound_state_ & MAX_UNBOUNDED) {
new_point = true;
bound_state_ ^= MAX_UNBOUNDED; // exclusive or removes flag.
} else {
if (collinear_order(ispoint, max_) == 1)
new_point = true;
}
if (new_point) {
if (!(bound_state_ & MIN_UNBOUNDED)
&& collinear_order(ispoint, min_) == 1)
bound_state_ = LINE_EMPTY;
else
max_ = ispoint;
}
break;
}
break;
}
}
template <class R>
int
Straight_2_<R>::
collinear_order(Point_2<R> const &pt1, Point_2<R> const & pt2) const
// Compare two points on the support_ line.
// If the second point lies in the direction of the direction vector from
// the first point, the result is 1.
// Other results are -1 (other side) and 0 (coincidence).
{
int diffsign;
diffsign = CGAL_NTS sign(pt2.cartesian(main_dir_)-pt1.cartesian(main_dir_));
if (diffsign == 0)
return 0;
return (diffsign == dir_sign_) ? 1 : -1;
}
CGAL_END_NAMESPACE
@}
@$@<2D Straight stream declaration@>==@{
CGAL_BEGIN_NAMESPACE
#ifndef CGAL_NO_OSTREAM_INSERT_STRAIGHT_2
template <class R>
std::ostream& operator<<(std::ostream& os,const Straight_2_<R>& cv)
{
typedef Pm_straight_exact_traits<R> Traits;
typedef Straight_2_<R> Curve;
switch(cv.current_state())
{
case Curve::SEGMENT:
{
Segment_2<R> seg;
cv.current(seg);
return os << seg;
}
case Curve::RAY:
{
Ray_2<R> ray;
cv.current(ray);
return os << ray;
}
case Curve::LINE:
{
Line_2<R> line;
cv.current(line);
return os << line;
}
case Curve::POINT:
{
Point_2<R> p;
cv.current(p);
return os << p;
}
case Curve::EMPTY:
break;
}
CGAL_assertion_msg(
cv.current_state()==Curve::SEGMENT||
cv.current_state()==Curve::RAY||
cv.current_state()==Curve::LINE||
cv.current_state()==Curve::POINT||
cv.current_state()==Curve::EMPTY,
"\nUnknown type in std:: ostream& operator<<( \
std:: ostream& os,const Straight_2&)");
return os;
}
#endif //CGAL_NO_OSTREAM_INSERT_STRAIGHT_2
#ifndef CGAL_NO_ISTREAM_EXTRACT_STRAIGHT_2
template <class R>
std:: istream& operator>>(std:: istream& is,Straight_2_<R>& cv)
{
typedef Pm_straight_exact_traits<R> Traits;
typedef Straight_2_<R> Curve;
switch(cv.current_state())
{
case Curve::SEGMENT:
{
Segment_2<R> seg;
cv.current(seg);
return os >> seg;
}
case Curve::RAY:
{
Ray_2<R> ray;
cv.current(ray);
return os >> ray;
}
case Curve::LINE:
{
Line_2<R> line;
cv.current(line);
return os >> line;
}
case Curve::POINT:
{
Point_2<R> p;
cv.current(p);
return os >> p;
}
case Curve::EMPTY:
break;
}
CGAL_assertion_msg(
cv.current_state()==Curve::SEGMENT||
cv.current_state()==Curve::RAY||
cv.current_state()==Curve::LINE||
cv.current_state()==Curve::POINT||
cv.current_state()==Curve::EMPTY,
"\nUnknown type in std:: ostream& operator>>( \
std:: ostream& os,Straight_2&)");
return os;
}
#endif //CGAL_NO_ISTREAM_EXTRACT_STRAIGHT_2
CGAL_END_NAMESPACE
@}
@O@<../include/CGAL/Straight_2.h@>==@{
@<cgal_heading@>@(@-
include/CGAL/Straight_2.h@,@-
straight_2.fw@,@-
Geert-Jan Giezeman@,@-
MPI, Saarbruecken@)
#ifndef CGAL_STRAIGHT_2_H
#define CGAL_STRAIGHT_2_H
@<2D Straight declaration@>
#endif
@}
@O@<../include/CGAL/Straight_2_stream.h@>==@{
@<cgal_heading@>@(@-
include/CGAL/Straight_2_stream.h@,@-
straight_2.fw@,@-
Oren Nechushtan@,@-
MPI, Saarbruecken@)
#ifndef CGAL_STRAIGHT_2_STREAM_H
#define CGAL_STRAIGHT_2_STREAM_H
@<2D Straight stream declaration@>
#endif // CGAL_STRAIGHT_2_STREAM_H
@}
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