lemon/dim2.h
author deba
Wed, 07 Mar 2007 12:00:59 +0000
changeset 2400 b199ded24c19
parent 2217 4a10a45d55f6
child 2451 d7b7048e045b
permissions -rw-r--r--
Steiner 2-approximation demo
     1 /* -*- C++ -*-
     2  *
     3  * This file is a part of LEMON, a generic C++ optimization library
     4  *
     5  * Copyright (C) 2003-2007
     6  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
     7  * (Egervary Research Group on Combinatorial Optimization, EGRES).
     8  *
     9  * Permission to use, modify and distribute this software is granted
    10  * provided that this copyright notice appears in all copies. For
    11  * precise terms see the accompanying LICENSE file.
    12  *
    13  * This software is provided "AS IS" with no warranty of any kind,
    14  * express or implied, and with no claim as to its suitability for any
    15  * purpose.
    16  *
    17  */
    18 
    19 #ifndef LEMON_DIM2_H
    20 #define LEMON_DIM2_H
    21 
    22 #include <iostream>
    23 #include <lemon/bits/utility.h>
    24 
    25 ///\ingroup misc
    26 ///\file
    27 ///\brief A simple two dimensional vector and a bounding box implementation 
    28 ///
    29 /// The class \ref lemon::dim2::Point "dim2::Point" implements
    30 ///a two dimensional vector with the usual
    31 /// operations.
    32 ///
    33 /// The class \ref lemon::dim2::BoundingBox "dim2::BoundingBox"
    34 /// can be used to determine
    35 /// the rectangular bounding box of a set of
    36 /// \ref lemon::dim2::Point "dim2::Point"'s.
    37 ///
    38 ///\author Attila Bernath
    39 
    40 
    41 namespace lemon {
    42 
    43   ///Tools for handling two dimensional coordinates
    44 
    45   ///This namespace is a storage of several
    46   ///tools for handling two dimensional coordinates
    47   namespace dim2 {
    48 
    49   /// \addtogroup misc
    50   /// @{
    51 
    52   /// A simple two dimensional vector (plainvector) implementation
    53 
    54   /// A simple two dimensional vector (plainvector) implementation
    55   ///with the usual vector
    56   /// operators.
    57   ///
    58   template<typename T>
    59     class Point {
    60 
    61     public:
    62 
    63       typedef T Value;
    64 
    65       ///First co-ordinate
    66       T x;
    67       ///Second co-ordinate
    68       T y;     
    69       
    70       ///Default constructor
    71       Point() {}
    72 
    73       ///Construct an instance from coordinates
    74       Point(T a, T b) : x(a), y(b) { }
    75 
    76       ///The dimension of the vector.
    77 
    78       ///This class give back always 2.
    79       ///
    80       int size() const { return 2; }
    81 
    82       ///Subscripting operator
    83 
    84       ///\c p[0] is \c p.x and \c p[1] is \c p.y
    85       ///
    86       T& operator[](int idx) { return idx == 0 ? x : y; }
    87 
    88       ///Const subscripting operator
    89 
    90       ///\c p[0] is \c p.x and \c p[1] is \c p.y
    91       ///
    92       const T& operator[](int idx) const { return idx == 0 ? x : y; }
    93 
    94       ///Conversion constructor
    95       template<class TT> Point(const Point<TT> &p) : x(p.x), y(p.y) {}
    96 
    97       ///Give back the square of the norm of the vector
    98       T normSquare() const {
    99         return x*x+y*y;
   100       }
   101   
   102       ///Increment the left hand side by u
   103       Point<T>& operator +=(const Point<T>& u) {
   104         x += u.x;
   105         y += u.y;
   106         return *this;
   107       }
   108   
   109       ///Decrement the left hand side by u
   110       Point<T>& operator -=(const Point<T>& u) {
   111         x -= u.x;
   112         y -= u.y;
   113         return *this;
   114       }
   115 
   116       ///Multiply the left hand side with a scalar
   117       Point<T>& operator *=(const T &u) {
   118         x *= u;
   119         y *= u;
   120         return *this;
   121       }
   122 
   123       ///Divide the left hand side by a scalar
   124       Point<T>& operator /=(const T &u) {
   125         x /= u;
   126         y /= u;
   127         return *this;
   128       }
   129   
   130       ///Return the scalar product of two vectors
   131       T operator *(const Point<T>& u) const {
   132         return x*u.x+y*u.y;
   133       }
   134   
   135       ///Return the sum of two vectors
   136       Point<T> operator+(const Point<T> &u) const {
   137         Point<T> b=*this;
   138         return b+=u;
   139       }
   140 
   141       ///Return the neg of the vectors
   142       Point<T> operator-() const {
   143         Point<T> b=*this;
   144         b.x=-b.x; b.y=-b.y;
   145         return b;
   146       }
   147 
   148       ///Return the difference of two vectors
   149       Point<T> operator-(const Point<T> &u) const {
   150         Point<T> b=*this;
   151         return b-=u;
   152       }
   153 
   154       ///Return a vector multiplied by a scalar
   155       Point<T> operator*(const T &u) const {
   156         Point<T> b=*this;
   157         return b*=u;
   158       }
   159 
   160       ///Return a vector divided by a scalar
   161       Point<T> operator/(const T &u) const {
   162         Point<T> b=*this;
   163         return b/=u;
   164       }
   165 
   166       ///Test equality
   167       bool operator==(const Point<T> &u) const {
   168         return (x==u.x) && (y==u.y);
   169       }
   170 
   171       ///Test inequality
   172       bool operator!=(Point u) const {
   173         return  (x!=u.x) || (y!=u.y);
   174       }
   175 
   176     };
   177 
   178   ///Return an Point 
   179 
   180   ///Return an Point
   181   ///\relates Point
   182   template <typename T>
   183   inline Point<T> makePoint(const T& x, const T& y) {
   184     return Point<T>(x, y);
   185   }
   186 
   187   ///Return a vector multiplied by a scalar
   188 
   189   ///Return a vector multiplied by a scalar
   190   ///\relates Point
   191   template<typename T> Point<T> operator*(const T &u,const Point<T> &x) {
   192     return x*u;
   193   }
   194 
   195   ///Read a plainvector from a stream
   196 
   197   ///Read a plainvector from a stream
   198   ///\relates Point
   199   ///
   200   template<typename T>
   201   inline std::istream& operator>>(std::istream &is, Point<T> &z) {
   202     char c;
   203     if (is >> c) {
   204       if (c != '(') is.putback(c);
   205     } else {
   206       is.clear();
   207     }
   208     if (!(is >> z.x)) return is;
   209     if (is >> c) {
   210       if (c != ',') is.putback(c);
   211     } else {
   212       is.clear();
   213     }
   214     if (!(is >> z.y)) return is;
   215     if (is >> c) {
   216       if (c != ')') is.putback(c);
   217     } else {
   218       is.clear();
   219     }
   220     return is;
   221   }
   222 
   223   ///Write a plainvector to a stream
   224 
   225   ///Write a plainvector to a stream
   226   ///\relates Point
   227   ///
   228   template<typename T>
   229   inline std::ostream& operator<<(std::ostream &os, const Point<T>& z)
   230   {
   231     os << "(" << z.x << ", " << z.y << ")";
   232     return os;
   233   }
   234 
   235   ///Rotate by 90 degrees
   236 
   237   ///Returns its parameter rotated by 90 degrees in positive direction.
   238   ///\relates Point
   239   ///
   240   template<typename T>
   241   inline Point<T> rot90(const Point<T> &z)
   242   {
   243     return Point<T>(-z.y,z.x);
   244   }
   245 
   246   ///Rotate by 180 degrees
   247 
   248   ///Returns its parameter rotated by 180 degrees.
   249   ///\relates Point
   250   ///
   251   template<typename T>
   252   inline Point<T> rot180(const Point<T> &z)
   253   {
   254     return Point<T>(-z.x,-z.y);
   255   }
   256 
   257   ///Rotate by 270 degrees
   258 
   259   ///Returns its parameter rotated by 90 degrees in negative direction.
   260   ///\relates Point
   261   ///
   262   template<typename T>
   263   inline Point<T> rot270(const Point<T> &z)
   264   {
   265     return Point<T>(z.y,-z.x);
   266   }
   267 
   268   
   269 
   270   /// A class to calculate or store the bounding box of plainvectors.
   271 
   272   /// A class to calculate or store the bounding box of plainvectors.
   273   ///
   274   ///\author Attila Bernath
   275   template<typename T>
   276     class BoundingBox {
   277       Point<T> bottom_left, top_right;
   278       bool _empty;
   279     public:
   280       
   281       ///Default constructor: creates an empty bounding box
   282       BoundingBox() { _empty = true; }
   283 
   284       ///Construct an instance from one point
   285       BoundingBox(Point<T> a) { bottom_left=top_right=a; _empty = false; }
   286 
   287       ///Were any points added?
   288       bool empty() const {
   289         return _empty;
   290       }
   291 
   292       ///Make the BoundingBox empty
   293       void clear() {
   294         _empty=1;
   295       }
   296 
   297       ///Give back the bottom left corner
   298 
   299       ///Give back the bottom left corner.
   300       ///If the bounding box is empty, then the return value is not defined.
   301       Point<T> bottomLeft() const {
   302         return bottom_left;
   303       }
   304 
   305       ///Set the bottom left corner
   306 
   307       ///Set the bottom left corner.
   308       ///It should only bee used for non-empty box.
   309       void bottomLeft(Point<T> p) {
   310 	bottom_left = p;
   311       }
   312 
   313       ///Give back the top right corner
   314 
   315       ///Give back the top right corner.
   316       ///If the bounding box is empty, then the return value is not defined.
   317       Point<T> topRight() const {
   318         return top_right;
   319       }
   320 
   321       ///Set the top right corner
   322 
   323       ///Set the top right corner.
   324       ///It should only bee used for non-empty box.
   325       void topRight(Point<T> p) {
   326 	top_right = p;
   327       }
   328 
   329       ///Give back the bottom right corner
   330 
   331       ///Give back the bottom right corner.
   332       ///If the bounding box is empty, then the return value is not defined.
   333       Point<T> bottomRight() const {
   334         return Point<T>(top_right.x,bottom_left.y);
   335       }
   336 
   337       ///Set the bottom right corner
   338 
   339       ///Set the bottom right corner.
   340       ///It should only bee used for non-empty box.
   341       void bottomRight(Point<T> p) {
   342 	top_right.x = p.x;
   343 	bottom_left.y = p.y;
   344       }
   345  
   346       ///Give back the top left corner
   347 
   348       ///Give back the top left corner.
   349       ///If the bounding box is empty, then the return value is not defined.
   350       Point<T> topLeft() const {
   351         return Point<T>(bottom_left.x,top_right.y);
   352       }
   353 
   354       ///Set the top left corner
   355 
   356       ///Set the top left corner.
   357       ///It should only bee used for non-empty box.
   358       void topLeft(Point<T> p) {
   359 	top_right.y = p.y;
   360 	bottom_left.x = p.x;
   361       }
   362 
   363       ///Give back the bottom of the box
   364 
   365       ///Give back the bottom of the box.
   366       ///If the bounding box is empty, then the return value is not defined.
   367       T bottom() const {
   368         return bottom_left.y;
   369       }
   370 
   371       ///Set the bottom of the box
   372 
   373       ///Set the bottom of the box.
   374       ///It should only bee used for non-empty box.
   375       void bottom(T t) {
   376 	bottom_left.y = t;
   377       }
   378 
   379       ///Give back the top of the box
   380 
   381       ///Give back the top of the box.
   382       ///If the bounding box is empty, then the return value is not defined.
   383       T top() const {
   384         return top_right.y;
   385       }
   386 
   387       ///Set the top of the box
   388 
   389       ///Set the top of the box.
   390       ///It should only bee used for non-empty box.
   391       void top(T t) {
   392 	top_right.y = t;
   393       }
   394 
   395       ///Give back the left side of the box
   396 
   397       ///Give back the left side of the box.
   398       ///If the bounding box is empty, then the return value is not defined.
   399       T left() const {
   400         return bottom_left.x;
   401       }
   402  
   403       ///Set the left side of the box
   404 
   405       ///Set the left side of the box.
   406       ///It should only bee used for non-empty box
   407       void left(T t) {
   408 	bottom_left.x = t;
   409       }
   410 
   411       /// Give back the right side of the box
   412 
   413       /// Give back the right side of the box.
   414       ///If the bounding box is empty, then the return value is not defined.
   415       T right() const {
   416         return top_right.x;
   417       }
   418 
   419       ///Set the right side of the box
   420 
   421       ///Set the right side of the box.
   422       ///It should only bee used for non-empty box
   423       void right(T t) {
   424 	top_right.x = t;
   425       }
   426 
   427       ///Give back the height of the box
   428 
   429       ///Give back the height of the box.
   430       ///If the bounding box is empty, then the return value is not defined.
   431       T height() const {
   432         return top_right.y-bottom_left.y;
   433       }
   434 
   435       ///Give back the width of the box
   436 
   437       ///Give back the width of the box.
   438       ///If the bounding box is empty, then the return value is not defined.
   439       T width() const {
   440         return top_right.x-bottom_left.x;
   441       }
   442 
   443       ///Checks whether a point is inside a bounding box
   444       bool inside(const Point<T>& u){
   445         if (_empty)
   446           return false;
   447         else{
   448           return ((u.x-bottom_left.x)*(top_right.x-u.x) >= 0 &&
   449               (u.y-bottom_left.y)*(top_right.y-u.y) >= 0 );
   450         }
   451       }
   452   
   453       ///Increments a bounding box with a point
   454       BoundingBox& add(const Point<T>& u){
   455         if (_empty){
   456           bottom_left=top_right=u;
   457           _empty = false;
   458         }
   459         else{
   460           if (bottom_left.x > u.x) bottom_left.x = u.x;
   461           if (bottom_left.y > u.y) bottom_left.y = u.y;
   462           if (top_right.x < u.x) top_right.x = u.x;
   463           if (top_right.y < u.y) top_right.y = u.y;
   464         }
   465         return *this;
   466       }
   467     
   468       ///Increments a bounding to contain another bounding box
   469       BoundingBox& add(const BoundingBox &u){
   470         if ( !u.empty() ){
   471           this->add(u.bottomLeft());
   472 	  this->add(u.topRight());
   473         }
   474         return *this;
   475       }
   476   
   477       ///Intersection of two bounding boxes
   478       BoundingBox operator &(const BoundingBox& u){
   479         BoundingBox b;
   480 	b.bottom_left.x=std::max(this->bottom_left.x,u.bottom_left.x);
   481 	b.bottom_left.y=std::max(this->bottom_left.y,u.bottom_left.y);
   482 	b.top_right.x=std::min(this->top_right.x,u.top_right.x);
   483 	b.top_right.y=std::min(this->top_right.y,u.top_right.y);
   484 	b._empty = this->_empty || u._empty ||
   485 	  b.bottom_left.x>top_right.x && b.bottom_left.y>top_right.y;
   486         return b;
   487       }
   488 
   489     };//class Boundingbox
   490 
   491 
   492   ///Map of x-coordinates of a dim2::Point<>-map
   493 
   494   ///\ingroup maps
   495   ///Map of x-coordinates of a dim2::Point<>-map
   496   ///
   497   template<class M>
   498   class XMap 
   499   {
   500     M& _map;
   501   public:
   502 
   503     typedef typename M::Value::Value Value;
   504     typedef typename M::Key Key;
   505     ///\e
   506     XMap(M& map) : _map(map) {}
   507     Value operator[](Key k) const {return _map[k].x;}
   508     void set(Key k,Value v) {_map.set(k,typename M::Value(v,_map[k].y));}
   509   };
   510     
   511   ///Returns an \ref XMap class
   512 
   513   ///This function just returns an \ref XMap class.
   514   ///
   515   ///\ingroup maps
   516   ///\relates XMap
   517   template<class M> 
   518   inline XMap<M> xMap(M &m) 
   519   {
   520     return XMap<M>(m);
   521   }
   522 
   523   template<class M> 
   524   inline XMap<M> xMap(const M &m) 
   525   {
   526     return XMap<M>(m);
   527   }
   528 
   529   ///Constant (read only) version of \ref XMap
   530 
   531   ///\ingroup maps
   532   ///Constant (read only) version of \ref XMap
   533   ///
   534   template<class M>
   535   class ConstXMap 
   536   {
   537     const M& _map;
   538   public:
   539 
   540     typedef typename M::Value::Value Value;
   541     typedef typename M::Key Key;
   542     ///\e
   543     ConstXMap(const M &map) : _map(map) {}
   544     Value operator[](Key k) const {return _map[k].x;}
   545   };
   546     
   547   ///Returns a \ref ConstXMap class
   548 
   549   ///This function just returns an \ref ConstXMap class.
   550   ///
   551   ///\ingroup maps
   552   ///\relates ConstXMap
   553   template<class M> 
   554   inline ConstXMap<M> xMap(const M &m) 
   555   {
   556     return ConstXMap<M>(m);
   557   }
   558 
   559   ///Map of y-coordinates of a dim2::Point<>-map
   560     
   561   ///\ingroup maps
   562   ///Map of y-coordinates of a dim2::Point<>-map
   563   ///
   564   template<class M>
   565   class YMap 
   566   {
   567     M& _map;
   568   public:
   569 
   570     typedef typename M::Value::Value Value;
   571     typedef typename M::Key Key;
   572     ///\e
   573     YMap(M& map) : _map(map) {}
   574     Value operator[](Key k) const {return _map[k].y;}
   575     void set(Key k,Value v) {_map.set(k,typename M::Value(_map[k].x,v));}
   576   };
   577 
   578   ///Returns an \ref YMap class
   579 
   580   ///This function just returns an \ref YMap class.
   581   ///
   582   ///\ingroup maps
   583   ///\relates YMap
   584   template<class M> 
   585   inline YMap<M> yMap(M &m) 
   586   {
   587     return YMap<M>(m);
   588   }
   589 
   590   template<class M> 
   591   inline YMap<M> yMap(const M &m) 
   592   {
   593     return YMap<M>(m);
   594   }
   595 
   596   ///Constant (read only) version of \ref YMap
   597 
   598   ///\ingroup maps
   599   ///Constant (read only) version of \ref YMap
   600   ///
   601   template<class M>
   602   class ConstYMap 
   603   {
   604     const M& _map;
   605   public:
   606 
   607     typedef typename M::Value::Value Value;
   608     typedef typename M::Key Key;
   609     ///\e
   610     ConstYMap(const M &map) : _map(map) {}
   611     Value operator[](Key k) const {return _map[k].y;}
   612   };
   613     
   614   ///Returns a \ref ConstYMap class
   615 
   616   ///This function just returns an \ref ConstYMap class.
   617   ///
   618   ///\ingroup maps
   619   ///\relates ConstYMap
   620   template<class M> 
   621   inline ConstYMap<M> yMap(const M &m) 
   622   {
   623     return ConstYMap<M>(m);
   624   }
   625 
   626 
   627     ///\brief Map of the \ref Point::normSquare() "normSquare()"
   628     ///of an \ref Point "Point"-map
   629     ///
   630     ///Map of the \ref Point::normSquare() "normSquare()"
   631     ///of an \ref Point "Point"-map
   632     ///\ingroup maps
   633     ///
   634   template<class M>
   635   class NormSquareMap 
   636   {
   637     const M& _map;
   638   public:
   639 
   640     typedef typename M::Value::Value Value;
   641     typedef typename M::Key Key;
   642     ///\e
   643     NormSquareMap(const M &map) : _map(map) {}
   644     Value operator[](Key k) const {return _map[k].normSquare();}
   645   };
   646     
   647   ///Returns a \ref NormSquareMap class
   648 
   649   ///This function just returns an \ref NormSquareMap class.
   650   ///
   651   ///\ingroup maps
   652   ///\relates NormSquareMap
   653   template<class M> 
   654   inline NormSquareMap<M> normSquareMap(const M &m) 
   655   {
   656     return NormSquareMap<M>(m);
   657   }
   658 
   659   /// @}
   660 
   661   } //namespce dim2
   662   
   663 } //namespace lemon
   664 
   665 #endif //LEMON_DIM2_H