256 lines
8.4 KiB
C++
Executable File
256 lines
8.4 KiB
C++
Executable File
// Copyright (c) 2000,2001
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// Utrecht University (The Netherlands),
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// ETH Zurich (Switzerland),
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// INRIA Sophia-Antipolis (France),
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// Max-Planck-Institute Saarbruecken (Germany),
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// and Tel-Aviv University (Israel). All rights reserved.
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//
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// This file is part of CGAL (www.cgal.org); you can redistribute it and/or
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// modify it under the terms of the GNU Lesser General Public License as
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// published by the Free Software Foundation; either version 3 of the License,
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// or (at your option) any later version.
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//
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// Licensees holding a valid commercial license may use this file in
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// accordance with the commercial license agreement provided with the software.
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//
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// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
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// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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//
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// $URL$
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// $Id$
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// SPDX-License-Identifier: LGPL-3.0+
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//
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//
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// Author(s) : Michael Seel
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#ifndef CGAL_SEGMENT_D_H
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#define CGAL_SEGMENT_D_H
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#include <CGAL/Kernel_d/Pair_d.h>
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#include <CGAL/Kernel_d/Point_d.h>
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#include <CGAL/Kernel_d/Segment_d.h>
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#include <CGAL/Kernel_d/Line_d.h>
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#include <CGAL/Kernel_d/Ray_d.h>
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#include <CGAL/Kernel_d/Aff_transformation_d.h>
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#include <CGAL/Dimension.h>
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namespace CGAL {
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template <class R> std::istream& operator>>
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(std::istream&, Segment_d<R>&);
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template <class R> std::ostream& operator<<
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(std::ostream&, const Segment_d<R>&);
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/*{\Manpage {Segment_d}{R}{Segments in d-space}{s}}*/
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template <class p_R>
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class Segment_d : public Handle_for< Pair_d<p_R> > {
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typedef Pair_d<p_R> Pair;
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typedef Handle_for<Pair> Base;
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typedef Segment_d<p_R> Self;
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using Base::ptr;
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/*{\Mdefinition
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An instance $s$ of the data type |Segment_d| is a directed straight
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line segment in $d$-dimensional Euclidian space connecting two points
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$p$ and $q$. $p$ is called the source point and $q$ is called
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the target point of $s$, both points are called endpoints of $s$. A
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segment whose endpoints are equal is called \emph{degenerate}.}*/
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public:
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typedef CGAL::Dynamic_dimension_tag Ambient_dimension;
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typedef CGAL::Dimension_tag<1> Feature_dimension;
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/*{\Mtypes 5}*/
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typedef p_R R;
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/*{\Mtypemember the representation type.}*/
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typedef typename p_R::RT RT;
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/*{\Mtypemember the ring type.}*/
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typedef typename p_R::FT FT;
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/*{\Mtypemember the field type.}*/
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typedef typename p_R::LA LA;
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/*{\Mtypemember the linear algebra layer.}*/
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friend class Line_d<R>;
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friend class Ray_d<R>;
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private:
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Segment_d(const Base& b) : Base(b) {}
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public:
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/*{\Mcreation 3}*/
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Segment_d() : Base( Pair() ) {}
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/*{\Mcreate introduces a variable |\Mvar| of type |\Mname|.}*/
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Segment_d(const Point_d<R>& p, const Point_d<R>& q)
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/*{\Mcreate introduces a variable |\Mvar| of type |\Mname| which
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is initialized to the segment $(p,q)$. }*/
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: Base( Pair(p,q) ) {}
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Segment_d(const Point_d<R>& p, const Vector_d<R>& v)
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/*{\Mcreate introduces a variable |\Mvar| of type |\Mname| which
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is initialized to the segment |(p,p+v)|. }*/
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: Base( Pair(p,p+v) ) {}
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Segment_d(const Segment_d<R>& s) : Base(s) {}
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/*{\Moperations 3 3}*/
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int dimension() const { return (ptr()->_p[0].dimension()); }
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/*{\Mop returns the dimension of the underlying space. }*/
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Point_d<R> source() const { return ptr()->_p[0]; }
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/*{\Mop returns the source point of segment |\Mvar|. }*/
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Point_d<R> target() const { return ptr()->_p[1]; }
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/*{\Mop returns the target point of segment |\Mvar|. }*/
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// defined for historical reasons
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Point_d<R> vertex(int i) const
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/*{\Mop returns source or target of |\Mvar|: |vertex(0)| returns the
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source, |vertex(1)| returns the target. The parameter $i$ is taken
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modulo $2$, which gives easy access to the other vertex.
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\precond $i \geq 0$.}*/
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{ CGAL_assertion(i>=0); return ptr()->_p[i%2]; }
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Point_d<R> point(int i) const { return vertex(i); }
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/*{\Mop returns |vertex(i)|.}*/
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Point_d<R> operator[](int i) const { return vertex(i); }
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/*{\Marrop returns |vertex(i)|.}*/
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Point_d<R> min BOOST_PREVENT_MACRO_SUBSTITUTION () const
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/*{\Mop returns the lexicographically smaller vertex.}*/
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{ typename R::Compare_lexicographically_d cmp;
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if (cmp(source(),target()) == CGAL::SMALLER) return source();
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else return target();
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}
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Point_d<R> max BOOST_PREVENT_MACRO_SUBSTITUTION () const
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/*{\Mop returns the lexicographically larger vertex.}*/
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{ typename R::Compare_lexicographically_d cmp;
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if (cmp(source(),target()) == SMALLER) return target();
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else return source();
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}
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Segment_d<R> opposite() const
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/*{\Mop returns the segment |(target(),source())|.}*/
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{ return Segment_d<R>(target(),source()); }
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Direction_d<R> direction() const
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/*{\Mop returns the direction from source to target.\\
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\precond |\Mvar| is non-degenerate. }*/
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{ CGAL_assertion_msg((!is_degenerate()),
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"Segment_d::direction(): degenerate segment cannot be converted.");
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return ptr()->direction();
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}
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Vector_d<R> vector() const
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/*{\Mop returns the vector from source to target.}*/
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{ return ptr()->vector(); }
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FT squared_length() const
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/*{\Mop returns the square of the length of |\Mvar|.}*/
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{ return (target()-source()).squared_length(); }
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bool has_on(const Point_d<R>& p) const
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/*{\Mop returns true if $p$ lies on |\Mvar| and false otherwise. }*/
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{ if (is_degenerate()) return (source() == p);
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typename R::Position_on_line_d pos; FT l;
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if ( pos(p,source(),target(),l) ) return (FT(0)<=l && l<=FT(1));
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return false;
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}
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inline Line_d<R> supporting_line() const;
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/*{\Mop returns the supporting line of |\Mvar|.
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\precond |\Mvar| is non-degenerate. }*/
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Segment_d<R>
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transform(const Aff_transformation_d<R>& t) const
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/*{\Mop returns $t(s)$.}*/
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{ return Segment_d<R>(source().transform(t),
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target().transform(t)); }
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Segment_d<R> operator+(const Vector_d<R>& v) const
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/*{\Mbinop returns $s+v$, i.e., |\Mvar| translated by vector $v$.}*/
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{ return Segment_d<R>(source()+v,target()+v); }
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bool is_degenerate() const
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/*{\Mop returns true if |\Mvar| is degenerate i.e.
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|\Mvar.source()=\Mvar.target()|. }*/
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{ return ptr()->is_degenerate(); }
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bool operator==(const Segment_d<R>& t) const
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{ if (this->identical(t)) return true;
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return ((source() == t.source() &&
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target() == t.target())); }
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bool operator!=(const Segment_d<R>& t) const
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{ return !operator==(t); }
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friend std::istream& operator>> <>
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(std::istream&, Segment_d<R>&);
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friend std::ostream& operator<< <>
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(std::ostream&, const Segment_d<R>&);
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}; // end of class
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/*{\Mtext \headerline{Non-Member Functions} }*/
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template <class R>
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bool weak_equality(const Segment_d<R>& s, const Segment_d<R>& t)
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/*{\Mfunc Test for equality as unoriented segments.}*/
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{ return (s==t || s==t.opposite()); }
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template <class R>
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bool parallel(const Segment_d<R>& s1, const Segment_d<R>& s2)
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/*{\Mfunc return true if one of the segments is trivial or
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if the unoriented supporting lines are parallel. }*/
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{ return s1.is_degenerate() || s2.is_degenerate() ||
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s1.direction() == s2.direction() ||
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s1.direction() == -s2.direction(); }
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template <class R>
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bool common_endpoint(const Segment_d<R>& s1, const Segment_d<R>& s2,
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Point_d<R>& common)
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/*{\Mfunc if |s1| and |s2| touch in a common end point, this point
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is assigned to |common| and the result is |true|, otherwise the
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result is |false|. }*/
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{ if (s1.source() == s2.source()) { common = s1.source(); return true; }
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if (s1.source() == s2.target()) { common = s1.source(); return true; }
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if (s1.target() == s2.source()) { common = s1.target(); return true; }
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if (s1.target() == s2.target()) { common = s1.target(); return true; }
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return false;
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}
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template <class R>
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std::istream& operator>>(std::istream& I, Segment_d<R>& s)
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{ s.copy_on_write(); s.ptr()->read(I);
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CGAL_assertion_msg(s.source().dimension()==s.target().dimension(),
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"Segment_d::operator>>: dimensions disagree.");
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return I;
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}
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template <class R>
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std::ostream& operator<<(std::ostream& O, const Segment_d<R>& s)
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{ s.ptr()->print(O,"Segment_d"); return O; }
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/*{\Mimplementation
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Segments are implemented by a pair of points as an item type. All
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operations like creation, initialization, tests, the calculation of
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the direction and source - target vector, input and output on a
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segment $s$ take time $O(|s.dimension()|)$. |dimension()|, coordinate
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and end point access, and identity test take constant time. The
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operations for intersection calculation also take time
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$O(|s.dimension()|)$. The space requirement is $O(|s.dimension()|)$.
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}*/
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} //namespace CGAL
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#endif // CGAL_SEGMENT_D_H
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//----------------------- end of file ----------------------------------
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