lemon/xy.h
author deba
Wed, 25 Jan 2006 14:58:04 +0000
changeset 1904 a64e4735bda6
parent 1706 163746ec3094
child 1927 12f289d6187f
permissions -rw-r--r--
Bug fix for empty intervall sorting
     1 /* -*- C++ -*-
     2  * lemon/xy.h - Part of LEMON, a generic C++ optimization library
     3  *
     4  * Copyright (C) 2006 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
     5  * (Egervary Research Group on Combinatorial Optimization, EGRES).
     6  *
     7  * Permission to use, modify and distribute this software is granted
     8  * provided that this copyright notice appears in all copies. For
     9  * precise terms see the accompanying LICENSE file.
    10  *
    11  * This software is provided "AS IS" with no warranty of any kind,
    12  * express or implied, and with no claim as to its suitability for any
    13  * purpose.
    14  *
    15  */
    16 
    17 #ifndef LEMON_XY_H
    18 #define LEMON_XY_H
    19 
    20 #include <iostream>
    21 #include <lemon/utility.h>
    22 
    23 ///\ingroup misc
    24 ///\file
    25 ///\brief A simple two dimensional vector and a bounding box implementation 
    26 ///
    27 /// The class \ref lemon::xy "xy" implements
    28 ///a two dimensional vector with the usual
    29 /// operations.
    30 ///
    31 /// The class \ref lemon::BoundingBox "BoundingBox" can be used to determine
    32 /// the rectangular bounding box of a set of \ref lemon::xy "xy"'s.
    33 ///
    34 ///\author Attila Bernath
    35 
    36 
    37 namespace lemon {
    38 
    39   /// \addtogroup misc
    40   /// @{
    41 
    42   /// A simple two dimensional vector (plainvector) implementation
    43 
    44   /// A simple two dimensional vector (plainvector) implementation
    45   ///with the usual vector
    46   /// operators.
    47   ///
    48   ///\author Attila Bernath
    49   template<typename T>
    50     class xy {
    51 
    52     public:
    53 
    54       typedef T Value;
    55 
    56       T x,y;     
    57       
    58       ///Default constructor
    59       xy() {}
    60 
    61       ///Constructing the instance from coordinates
    62       xy(T a, T b) : x(a), y(b) { }
    63 
    64 
    65       ///Conversion constructor
    66       template<class TT> xy(const xy<TT> &p) : x(p.x), y(p.y) {}
    67 
    68       ///Gives back the square of the norm of the vector
    69       T normSquare() const {
    70         return x*x+y*y;
    71       }
    72   
    73       ///Increments the left hand side by u
    74       xy<T>& operator +=(const xy<T>& u) {
    75         x += u.x;
    76         y += u.y;
    77         return *this;
    78       }
    79   
    80       ///Decrements the left hand side by u
    81       xy<T>& operator -=(const xy<T>& u) {
    82         x -= u.x;
    83         y -= u.y;
    84         return *this;
    85       }
    86 
    87       ///Multiplying the left hand side with a scalar
    88       xy<T>& operator *=(const T &u) {
    89         x *= u;
    90         y *= u;
    91         return *this;
    92       }
    93 
    94       ///Dividing the left hand side by a scalar
    95       xy<T>& operator /=(const T &u) {
    96         x /= u;
    97         y /= u;
    98         return *this;
    99       }
   100   
   101       ///Returns the scalar product of two vectors
   102       T operator *(const xy<T>& u) const {
   103         return x*u.x+y*u.y;
   104       }
   105   
   106       ///Returns the sum of two vectors
   107       xy<T> operator+(const xy<T> &u) const {
   108         xy<T> b=*this;
   109         return b+=u;
   110       }
   111 
   112       ///Returns the neg of the vectors
   113       xy<T> operator-() const {
   114         xy<T> b=*this;
   115         b.x=-b.x; b.y=-b.y;
   116         return b;
   117       }
   118 
   119       ///Returns the difference of two vectors
   120       xy<T> operator-(const xy<T> &u) const {
   121         xy<T> b=*this;
   122         return b-=u;
   123       }
   124 
   125       ///Returns a vector multiplied by a scalar
   126       xy<T> operator*(const T &u) const {
   127         xy<T> b=*this;
   128         return b*=u;
   129       }
   130 
   131       ///Returns a vector divided by a scalar
   132       xy<T> operator/(const T &u) const {
   133         xy<T> b=*this;
   134         return b/=u;
   135       }
   136 
   137       ///Testing equality
   138       bool operator==(const xy<T> &u) const {
   139         return (x==u.x) && (y==u.y);
   140       }
   141 
   142       ///Testing inequality
   143       bool operator!=(xy u) const {
   144         return  (x!=u.x) || (y!=u.y);
   145       }
   146 
   147     };
   148 
   149   ///Returns a vector multiplied by a scalar
   150 
   151   ///Returns a vector multiplied by a scalar
   152   ///\relates xy
   153   template<typename T> xy<T> operator*(const T &u,const xy<T> &x) {
   154     return x*u;
   155   }
   156 
   157   ///Read a plainvector from a stream
   158 
   159   ///Read a plainvector from a stream
   160   ///\relates xy
   161   ///
   162   template<typename T>
   163   inline std::istream& operator>>(std::istream &is, xy<T> &z) {
   164     char c;
   165     if (is >> c) {
   166       if (c != '(') is.putback(c);
   167     } else {
   168       is.clear();
   169     }
   170     if (!(is >> z.x)) return is;
   171     if (is >> c) {
   172       if (c != ',') is.putback(c);
   173     } else {
   174       is.clear();
   175     }
   176     if (!(is >> z.y)) return is;
   177     if (is >> c) {
   178       if (c != ')') is.putback(c);
   179     } else {
   180       is.clear();
   181     }
   182     return is;
   183   }
   184 
   185   ///Write a plainvector to a stream
   186 
   187   ///Write a plainvector to a stream
   188   ///\relates xy
   189   ///
   190   template<typename T>
   191   inline std::ostream& operator<<(std::ostream &os, const xy<T>& z)
   192   {
   193     os << "(" << z.x << ", " << z.y << ")";
   194     return os;
   195   }
   196 
   197   ///Rotate by 90 degrees
   198 
   199   ///Returns its parameter rotated by 90 degrees in positive direction.
   200   ///\relates xy
   201   ///
   202   template<typename T>
   203   inline xy<T> rot90(const xy<T> &z)
   204   {
   205     return xy<T>(-z.y,z.x);
   206   }
   207 
   208   ///Rotate by 270 degrees
   209 
   210   ///Returns its parameter rotated by 90 degrees in negative direction.
   211   ///\relates xy
   212   ///
   213   template<typename T>
   214   inline xy<T> rot270(const xy<T> &z)
   215   {
   216     return xy<T>(z.y,-z.x);
   217   }
   218 
   219   
   220 
   221   /// A class to calculate or store the bounding box of plainvectors.
   222 
   223   /// A class to calculate or store the bounding box of plainvectors.
   224   ///
   225   ///\author Attila Bernath
   226   template<typename T>
   227     class BoundingBox {
   228       xy<T> bottom_left, top_right;
   229       bool _empty;
   230     public:
   231       
   232       ///Default constructor: creates an empty bounding box
   233       BoundingBox() { _empty = true; }
   234 
   235       ///Constructing the instance from one point
   236       BoundingBox(xy<T> a) { bottom_left=top_right=a; _empty = false; }
   237 
   238       ///Were any points added?
   239       bool empty() const {
   240         return _empty;
   241       }
   242 
   243       ///Makes the BoundingBox empty
   244       void clear() {
   245         _empty=1;
   246       }
   247 
   248       ///Gives back the bottom left corner (if the bounding box is empty, then the return value is not defined) 
   249       xy<T> bottomLeft() const {
   250         return bottom_left;
   251       }
   252 
   253       ///Gives back the top right corner (if the bounding box is empty, then the return value is not defined) 
   254       xy<T> topRight() const {
   255         return top_right;
   256       }
   257 
   258       ///Gives back the bottom right corner (if the bounding box is empty, then the return value is not defined) 
   259       xy<T> bottomRight() const {
   260         return xy<T>(top_right.x,bottom_left.y);
   261       }
   262 
   263       ///Gives back the top left corner (if the bounding box is empty, then the return value is not defined) 
   264       xy<T> topLeft() const {
   265         return xy<T>(bottom_left.x,top_right.y);
   266       }
   267 
   268       ///Gives back the bottom of the box (if the bounding box is empty, then the return value is not defined) 
   269       T bottom() const {
   270         return bottom_left.y;
   271       }
   272 
   273       ///Gives back the top of the box (if the bounding box is empty, then the return value is not defined) 
   274       T top() const {
   275         return top_right.y;
   276       }
   277 
   278       ///Gives back the left side of the box (if the bounding box is empty, then the return value is not defined) 
   279       T left() const {
   280         return bottom_left.x;
   281       }
   282 
   283       ///Gives back the right side of the box (if the bounding box is empty, then the return value is not defined) 
   284       T right() const {
   285         return top_right.x;
   286       }
   287 
   288       ///Gives back the height of the box (if the bounding box is empty, then the return value is not defined) 
   289       T height() const {
   290         return top_right.y-bottom_left.y;
   291       }
   292 
   293       ///Gives back the width of the box (if the bounding box is empty, then the return value is not defined) 
   294       T width() const {
   295         return top_right.x-bottom_left.x;
   296       }
   297 
   298       ///Checks whether a point is inside a bounding box
   299       bool inside(const xy<T>& u){
   300         if (_empty)
   301           return false;
   302         else{
   303           return ((u.x-bottom_left.x)*(top_right.x-u.x) >= 0 &&
   304               (u.y-bottom_left.y)*(top_right.y-u.y) >= 0 );
   305         }
   306       }
   307   
   308       ///Increments a bounding box with a point
   309       BoundingBox& add(const xy<T>& u){
   310         if (_empty){
   311           bottom_left=top_right=u;
   312           _empty = false;
   313         }
   314         else{
   315           if (bottom_left.x > u.x) bottom_left.x = u.x;
   316           if (bottom_left.y > u.y) bottom_left.y = u.y;
   317           if (top_right.x < u.x) top_right.x = u.x;
   318           if (top_right.y < u.y) top_right.y = u.y;
   319         }
   320         return *this;
   321       }
   322   
   323 //       ///Sums a bounding box and a point
   324 //       BoundingBox operator +(const xy<T>& u){
   325 //         BoundingBox b = *this;
   326 //         return b += u;
   327 //       }
   328 
   329       ///Increments a bounding box with an other bounding box
   330       BoundingBox& add(const BoundingBox &u){
   331         if ( !u.empty() ){
   332           this->add(u.bottomLeft());
   333 	  this->add(u.topRight());
   334         }
   335         return *this;
   336       }
   337   
   338       ///Sums two bounding boxes
   339       BoundingBox operator +(const BoundingBox& u){
   340         BoundingBox b = *this;
   341         return b.add(u);
   342       }
   343 
   344 
   345       ///Intersection of two bounding boxes
   346       BoundingBox operator &(const BoundingBox& u){
   347         BoundingBox b;
   348 	b.bottom_left.x=std::max(this->bottom_left.x,u.bottom_left.x);
   349 	b.bottom_left.y=std::max(this->bottom_left.y,u.bottom_left.y);
   350 	b.top_right.x=std::min(this->top_right.x,u.top_right.x);
   351 	b.top_right.y=std::min(this->top_right.y,u.top_right.y);
   352 	b._empty = this->_empty || u._empty ||
   353 	  b.bottom_left.x>top_right.x && b.bottom_left.y>top_right.y;
   354         return b;
   355       }
   356 
   357     };//class Boundingbox
   358 
   359 
   360   ///Map of x-coordinates of an xy<>-map
   361 
   362   ///\ingroup maps
   363   ///
   364   template<class M>
   365   class XMap 
   366   {
   367     M& _map;
   368   public:
   369 
   370     typedef typename M::Value::Value Value;
   371     typedef typename M::Key Key;
   372     ///\e
   373     XMap(M& map) : _map(map) {}
   374     Value operator[](Key k) const {return _map[k].x;}
   375     void set(Key k,Value v) {_map.set(k,typename M::Value(v,_map[k].y));}
   376   };
   377     
   378   ///Returns an \ref XMap class
   379 
   380   ///This function just returns an \ref XMap class.
   381   ///
   382   ///\ingroup maps
   383   ///\relates XMap
   384   template<class M> 
   385   inline XMap<M> xMap(M &m) 
   386   {
   387     return XMap<M>(m);
   388   }
   389 
   390   template<class M> 
   391   inline XMap<M> xMap(const M &m) 
   392   {
   393     return XMap<M>(m);
   394   }
   395 
   396   ///Constant (read only) version of \ref XMap
   397 
   398   ///\ingroup maps
   399   ///
   400   template<class M>
   401   class ConstXMap 
   402   {
   403     const M& _map;
   404   public:
   405 
   406     typedef typename M::Value::Value Value;
   407     typedef typename M::Key Key;
   408     ///\e
   409     ConstXMap(const M &map) : _map(map) {}
   410     Value operator[](Key k) const {return _map[k].x;}
   411   };
   412     
   413   ///Returns a \ref ConstXMap class
   414 
   415   ///This function just returns an \ref ConstXMap class.
   416   ///
   417   ///\ingroup maps
   418   ///\relates ConstXMap
   419   template<class M> 
   420   inline ConstXMap<M> xMap(const M &m) 
   421   {
   422     return ConstXMap<M>(m);
   423   }
   424 
   425   ///Map of y-coordinates of an xy<>-map
   426     
   427   ///\ingroup maps
   428   ///
   429   template<class M>
   430   class YMap 
   431   {
   432     M& _map;
   433   public:
   434 
   435     typedef typename M::Value::Value Value;
   436     typedef typename M::Key Key;
   437     ///\e
   438     YMap(M& map) : _map(map) {}
   439     Value operator[](Key k) const {return _map[k].y;}
   440     void set(Key k,Value v) {_map.set(k,typename M::Value(_map[k].x,v));}
   441   };
   442 
   443   ///Returns an \ref YMap class
   444 
   445   ///This function just returns an \ref YMap class.
   446   ///
   447   ///\ingroup maps
   448   ///\relates YMap
   449   template<class M> 
   450   inline YMap<M> yMap(M &m) 
   451   {
   452     return YMap<M>(m);
   453   }
   454 
   455   template<class M> 
   456   inline YMap<M> yMap(const M &m) 
   457   {
   458     return YMap<M>(m);
   459   }
   460 
   461   ///Constant (read only) version of \ref YMap
   462 
   463   ///\ingroup maps
   464   ///
   465   template<class M>
   466   class ConstYMap 
   467   {
   468     const M& _map;
   469   public:
   470 
   471     typedef typename M::Value::Value Value;
   472     typedef typename M::Key Key;
   473     ///\e
   474     ConstYMap(const M &map) : _map(map) {}
   475     Value operator[](Key k) const {return _map[k].y;}
   476   };
   477     
   478   ///Returns a \ref ConstYMap class
   479 
   480   ///This function just returns an \ref ConstYMap class.
   481   ///
   482   ///\ingroup maps
   483   ///\relates ConstYMap
   484   template<class M> 
   485   inline ConstYMap<M> yMap(const M &m) 
   486   {
   487     return ConstYMap<M>(m);
   488   }
   489 
   490 
   491   ///Map of the \ref xy::normSquare() "normSquare()" of an \ref xy "xy"-map
   492 
   493   ///Map of the \ref xy::normSquare() "normSquare()" of an \ref xy "xy"-map
   494   ///\ingroup maps
   495   ///
   496   template<class M>
   497   class NormSquareMap 
   498   {
   499     const M& _map;
   500   public:
   501 
   502     typedef typename M::Value::Value Value;
   503     typedef typename M::Key Key;
   504     ///\e
   505     NormSquareMap(const M &map) : _map(map) {}
   506     Value operator[](Key k) const {return _map[k].normSquare();}
   507   };
   508     
   509   ///Returns a \ref NormSquareMap class
   510 
   511   ///This function just returns an \ref NormSquareMap class.
   512   ///
   513   ///\ingroup maps
   514   ///\relates NormSquareMap
   515   template<class M> 
   516   inline NormSquareMap<M> normSquareMap(const M &m) 
   517   {
   518     return NormSquareMap<M>(m);
   519   }
   520 
   521   /// @}
   522 
   523 
   524 } //namespace lemon
   525 
   526 #endif //LEMON_XY_H