lemon/xy.h
author alpar
Mon, 04 Sep 2006 19:48:09 +0000
changeset 2195 f47faf6913ab
parent 2006 00d59f733817
permissions -rw-r--r--
Tutorial improvements by Mark (mqrelly)
     1 /* -*- C++ -*-
     2  *
     3  * This file is a part of LEMON, a generic C++ optimization library
     4  *
     5  * Copyright (C) 2003-2006
     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_XY_H
    20 #define LEMON_XY_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::xy "xy" implements
    30 ///a two dimensional vector with the usual
    31 /// operations.
    32 ///
    33 /// The class \ref lemon::BoundingBox "BoundingBox" can be used to determine
    34 /// the rectangular bounding box of a set of \ref lemon::xy "xy"'s.
    35 ///
    36 ///\author Attila Bernath
    37 
    38 
    39 namespace lemon {
    40 
    41   /// \addtogroup misc
    42   /// @{
    43 
    44   /// A simple two dimensional vector (plainvector) implementation
    45 
    46   /// A simple two dimensional vector (plainvector) implementation
    47   ///with the usual vector
    48   /// operators.
    49   ///
    50   ///\note As you might have noticed, this class does not follow the
    51   ///\ref naming_conv "LEMON Coding Style" (it should be called \c Xy
    52   ///according to it). There is a stupid Hungarian proverb, "A kiv&eacute;tel
    53   ///er&otilde;s&iacute;ti a szab&aacute;lyt" ("An exception
    54   ///reinforces a rule", which is
    55   ///actually a mistranslation of the Latin proverb "Exceptio probat regulam").
    56   ///This class is an example for that.
    57   ///\author Attila Bernath
    58   template<typename T>
    59     class xy {
    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       xy() {}
    72 
    73       ///Construct an instance from coordinates
    74       xy(T a, T b) : x(a), y(b) { }
    75 
    76 
    77       ///Conversion constructor
    78       template<class TT> xy(const xy<TT> &p) : x(p.x), y(p.y) {}
    79 
    80       ///Give back the square of the norm of the vector
    81       T normSquare() const {
    82         return x*x+y*y;
    83       }
    84   
    85       ///Increment the left hand side by u
    86       xy<T>& operator +=(const xy<T>& u) {
    87         x += u.x;
    88         y += u.y;
    89         return *this;
    90       }
    91   
    92       ///Decrement the left hand side by u
    93       xy<T>& operator -=(const xy<T>& u) {
    94         x -= u.x;
    95         y -= u.y;
    96         return *this;
    97       }
    98 
    99       ///Multiply the left hand side with a scalar
   100       xy<T>& operator *=(const T &u) {
   101         x *= u;
   102         y *= u;
   103         return *this;
   104       }
   105 
   106       ///Divide the left hand side by a scalar
   107       xy<T>& operator /=(const T &u) {
   108         x /= u;
   109         y /= u;
   110         return *this;
   111       }
   112   
   113       ///Return the scalar product of two vectors
   114       T operator *(const xy<T>& u) const {
   115         return x*u.x+y*u.y;
   116       }
   117   
   118       ///Return the sum of two vectors
   119       xy<T> operator+(const xy<T> &u) const {
   120         xy<T> b=*this;
   121         return b+=u;
   122       }
   123 
   124       ///Return the neg of the vectors
   125       xy<T> operator-() const {
   126         xy<T> b=*this;
   127         b.x=-b.x; b.y=-b.y;
   128         return b;
   129       }
   130 
   131       ///Return the difference of two vectors
   132       xy<T> operator-(const xy<T> &u) const {
   133         xy<T> b=*this;
   134         return b-=u;
   135       }
   136 
   137       ///Return a vector multiplied by a scalar
   138       xy<T> operator*(const T &u) const {
   139         xy<T> b=*this;
   140         return b*=u;
   141       }
   142 
   143       ///Return a vector divided by a scalar
   144       xy<T> operator/(const T &u) const {
   145         xy<T> b=*this;
   146         return b/=u;
   147       }
   148 
   149       ///Test equality
   150       bool operator==(const xy<T> &u) const {
   151         return (x==u.x) && (y==u.y);
   152       }
   153 
   154       ///Test inequality
   155       bool operator!=(xy u) const {
   156         return  (x!=u.x) || (y!=u.y);
   157       }
   158 
   159     };
   160 
   161   ///Return an xy 
   162 
   163   ///Return an xy
   164   ///\relates xy
   165   template <typename T>
   166   inline xy<T> make_xy(const T& x, const T& y) {
   167     return xy<T>(x, y);
   168   }
   169 
   170   ///Return a vector multiplied by a scalar
   171 
   172   ///Return a vector multiplied by a scalar
   173   ///\relates xy
   174   template<typename T> xy<T> operator*(const T &u,const xy<T> &x) {
   175     return x*u;
   176   }
   177 
   178   ///Read a plainvector from a stream
   179 
   180   ///Read a plainvector from a stream
   181   ///\relates xy
   182   ///
   183   template<typename T>
   184   inline std::istream& operator>>(std::istream &is, xy<T> &z) {
   185     char c;
   186     if (is >> c) {
   187       if (c != '(') is.putback(c);
   188     } else {
   189       is.clear();
   190     }
   191     if (!(is >> z.x)) return is;
   192     if (is >> c) {
   193       if (c != ',') is.putback(c);
   194     } else {
   195       is.clear();
   196     }
   197     if (!(is >> z.y)) return is;
   198     if (is >> c) {
   199       if (c != ')') is.putback(c);
   200     } else {
   201       is.clear();
   202     }
   203     return is;
   204   }
   205 
   206   ///Write a plainvector to a stream
   207 
   208   ///Write a plainvector to a stream
   209   ///\relates xy
   210   ///
   211   template<typename T>
   212   inline std::ostream& operator<<(std::ostream &os, const xy<T>& z)
   213   {
   214     os << "(" << z.x << ", " << z.y << ")";
   215     return os;
   216   }
   217 
   218   ///Rotate by 90 degrees
   219 
   220   ///Returns its parameter rotated by 90 degrees in positive direction.
   221   ///\relates xy
   222   ///
   223   template<typename T>
   224   inline xy<T> rot90(const xy<T> &z)
   225   {
   226     return xy<T>(-z.y,z.x);
   227   }
   228 
   229   ///Rotate by 180 degrees
   230 
   231   ///Returns its parameter rotated by 180 degrees.
   232   ///\relates xy
   233   ///
   234   template<typename T>
   235   inline xy<T> rot180(const xy<T> &z)
   236   {
   237     return xy<T>(-z.x,-z.y);
   238   }
   239 
   240   ///Rotate by 270 degrees
   241 
   242   ///Returns its parameter rotated by 90 degrees in negative direction.
   243   ///\relates xy
   244   ///
   245   template<typename T>
   246   inline xy<T> rot270(const xy<T> &z)
   247   {
   248     return xy<T>(z.y,-z.x);
   249   }
   250 
   251   
   252 
   253   /// A class to calculate or store the bounding box of plainvectors.
   254 
   255   /// A class to calculate or store the bounding box of plainvectors.
   256   ///
   257   ///\author Attila Bernath
   258   template<typename T>
   259     class BoundingBox {
   260       xy<T> bottom_left, top_right;
   261       bool _empty;
   262     public:
   263       
   264       ///Default constructor: creates an empty bounding box
   265       BoundingBox() { _empty = true; }
   266 
   267       ///Construct an instance from one point
   268       BoundingBox(xy<T> a) { bottom_left=top_right=a; _empty = false; }
   269 
   270       ///Were any points added?
   271       bool empty() const {
   272         return _empty;
   273       }
   274 
   275       ///Make the BoundingBox empty
   276       void clear() {
   277         _empty=1;
   278       }
   279 
   280       ///Give back the bottom left corner
   281 
   282       ///Give back the bottom left corner.
   283       ///If the bounding box is empty, then the return value is not defined.
   284       xy<T> bottomLeft() const {
   285         return bottom_left;
   286       }
   287 
   288       ///Set the bottom left corner
   289 
   290       ///Set the bottom left corner.
   291       ///It should only bee used for non-empty box.
   292       void bottomLeft(xy<T> p) {
   293 	bottom_left = p;
   294       }
   295 
   296       ///Give back the top right corner
   297 
   298       ///Give back the top right corner.
   299       ///If the bounding box is empty, then the return value is not defined.
   300       xy<T> topRight() const {
   301         return top_right;
   302       }
   303 
   304       ///Set the top right corner
   305 
   306       ///Set the top right corner.
   307       ///It should only bee used for non-empty box.
   308       void topRight(xy<T> p) {
   309 	top_right = p;
   310       }
   311 
   312       ///Give back the bottom right corner
   313 
   314       ///Give back the bottom right corner.
   315       ///If the bounding box is empty, then the return value is not defined.
   316       xy<T> bottomRight() const {
   317         return xy<T>(top_right.x,bottom_left.y);
   318       }
   319 
   320       ///Set the bottom right corner
   321 
   322       ///Set the bottom right corner.
   323       ///It should only bee used for non-empty box.
   324       void bottomRight(xy<T> p) {
   325 	top_right.x = p.x;
   326 	bottom_left.y = p.y;
   327       }
   328  
   329       ///Give back the top left corner
   330 
   331       ///Give back the top left corner.
   332       ///If the bounding box is empty, then the return value is not defined.
   333       xy<T> topLeft() const {
   334         return xy<T>(bottom_left.x,top_right.y);
   335       }
   336 
   337       ///Set the top left corner
   338 
   339       ///Set the top left corner.
   340       ///It should only bee used for non-empty box.
   341       void topLeft(xy<T> p) {
   342 	top_right.y = p.y;
   343 	bottom_left.x = p.x;
   344       }
   345 
   346       ///Give back the bottom of the box
   347 
   348       ///Give back the bottom of the box.
   349       ///If the bounding box is empty, then the return value is not defined.
   350       T bottom() const {
   351         return bottom_left.y;
   352       }
   353 
   354       ///Set the bottom of the box
   355 
   356       ///Set the bottom of the box.
   357       ///It should only bee used for non-empty box.
   358       void bottom(T t) {
   359 	bottom_left.y = t;
   360       }
   361 
   362       ///Give back the top of the box
   363 
   364       ///Give back the top of the box.
   365       ///If the bounding box is empty, then the return value is not defined.
   366       T top() const {
   367         return top_right.y;
   368       }
   369 
   370       ///Set the top of the box
   371 
   372       ///Set the top of the box.
   373       ///It should only bee used for non-empty box.
   374       void top(T t) {
   375 	top_right.y = t;
   376       }
   377 
   378       ///Give back the left side of the box
   379 
   380       ///Give back the left side of the box.
   381       ///If the bounding box is empty, then the return value is not defined.
   382       T left() const {
   383         return bottom_left.x;
   384       }
   385  
   386       ///Set the left side of the box
   387 
   388       ///Set the left side of the box.
   389       ///It should only bee used for non-empty box
   390       void left(T t) {
   391 	bottom_left.x = t;
   392       }
   393 
   394       /// Give back the right side of the box
   395 
   396       /// Give back the right side of the box.
   397       ///If the bounding box is empty, then the return value is not defined.
   398       T right() const {
   399         return top_right.x;
   400       }
   401 
   402       ///Set the right side of the box
   403 
   404       ///Set the right side of the box.
   405       ///It should only bee used for non-empty box
   406       void right(T t) {
   407 	top_right.x = t;
   408       }
   409 
   410       ///Give back the height of the box
   411 
   412       ///Give back the height of the box.
   413       ///If the bounding box is empty, then the return value is not defined.
   414       T height() const {
   415         return top_right.y-bottom_left.y;
   416       }
   417 
   418       ///Give back the width of the box
   419 
   420       ///Give back the width of the box.
   421       ///If the bounding box is empty, then the return value is not defined.
   422       T width() const {
   423         return top_right.x-bottom_left.x;
   424       }
   425 
   426       ///Checks whether a point is inside a bounding box
   427       bool inside(const xy<T>& u){
   428         if (_empty)
   429           return false;
   430         else{
   431           return ((u.x-bottom_left.x)*(top_right.x-u.x) >= 0 &&
   432               (u.y-bottom_left.y)*(top_right.y-u.y) >= 0 );
   433         }
   434       }
   435   
   436       ///Increments a bounding box with a point
   437       BoundingBox& add(const xy<T>& u){
   438         if (_empty){
   439           bottom_left=top_right=u;
   440           _empty = false;
   441         }
   442         else{
   443           if (bottom_left.x > u.x) bottom_left.x = u.x;
   444           if (bottom_left.y > u.y) bottom_left.y = u.y;
   445           if (top_right.x < u.x) top_right.x = u.x;
   446           if (top_right.y < u.y) top_right.y = u.y;
   447         }
   448         return *this;
   449       }
   450   
   451 //       ///Sums a bounding box and a point
   452 //       BoundingBox operator +(const xy<T>& u){
   453 //         BoundingBox b = *this;
   454 //         return b += u;
   455 //       }
   456 
   457       ///Increments a bounding box with another bounding box
   458       BoundingBox& add(const BoundingBox &u){
   459         if ( !u.empty() ){
   460           this->add(u.bottomLeft());
   461 	  this->add(u.topRight());
   462         }
   463         return *this;
   464       }
   465   
   466       ///Sums two bounding boxes
   467       BoundingBox operator +(const BoundingBox& u){
   468         BoundingBox b = *this;
   469         return b.add(u);
   470       }
   471 
   472 
   473       ///Intersection of two bounding boxes
   474       BoundingBox operator &(const BoundingBox& u){
   475         BoundingBox b;
   476 	b.bottom_left.x=std::max(this->bottom_left.x,u.bottom_left.x);
   477 	b.bottom_left.y=std::max(this->bottom_left.y,u.bottom_left.y);
   478 	b.top_right.x=std::min(this->top_right.x,u.top_right.x);
   479 	b.top_right.y=std::min(this->top_right.y,u.top_right.y);
   480 	b._empty = this->_empty || u._empty ||
   481 	  b.bottom_left.x>top_right.x && b.bottom_left.y>top_right.y;
   482         return b;
   483       }
   484 
   485     };//class Boundingbox
   486 
   487 
   488   ///Map of x-coordinates of an xy<>-map
   489 
   490   ///\ingroup maps
   491   ///
   492   template<class M>
   493   class XMap 
   494   {
   495     M& _map;
   496   public:
   497 
   498     typedef typename M::Value::Value Value;
   499     typedef typename M::Key Key;
   500     ///\e
   501     XMap(M& map) : _map(map) {}
   502     Value operator[](Key k) const {return _map[k].x;}
   503     void set(Key k,Value v) {_map.set(k,typename M::Value(v,_map[k].y));}
   504   };
   505     
   506   ///Returns an \ref XMap class
   507 
   508   ///This function just returns an \ref XMap class.
   509   ///
   510   ///\ingroup maps
   511   ///\relates XMap
   512   template<class M> 
   513   inline XMap<M> xMap(M &m) 
   514   {
   515     return XMap<M>(m);
   516   }
   517 
   518   template<class M> 
   519   inline XMap<M> xMap(const M &m) 
   520   {
   521     return XMap<M>(m);
   522   }
   523 
   524   ///Constant (read only) version of \ref XMap
   525 
   526   ///\ingroup maps
   527   ///
   528   template<class M>
   529   class ConstXMap 
   530   {
   531     const M& _map;
   532   public:
   533 
   534     typedef typename M::Value::Value Value;
   535     typedef typename M::Key Key;
   536     ///\e
   537     ConstXMap(const M &map) : _map(map) {}
   538     Value operator[](Key k) const {return _map[k].x;}
   539   };
   540     
   541   ///Returns a \ref ConstXMap class
   542 
   543   ///This function just returns an \ref ConstXMap class.
   544   ///
   545   ///\ingroup maps
   546   ///\relates ConstXMap
   547   template<class M> 
   548   inline ConstXMap<M> xMap(const M &m) 
   549   {
   550     return ConstXMap<M>(m);
   551   }
   552 
   553   ///Map of y-coordinates of an xy<>-map
   554     
   555   ///\ingroup maps
   556   ///
   557   template<class M>
   558   class YMap 
   559   {
   560     M& _map;
   561   public:
   562 
   563     typedef typename M::Value::Value Value;
   564     typedef typename M::Key Key;
   565     ///\e
   566     YMap(M& map) : _map(map) {}
   567     Value operator[](Key k) const {return _map[k].y;}
   568     void set(Key k,Value v) {_map.set(k,typename M::Value(_map[k].x,v));}
   569   };
   570 
   571   ///Returns an \ref YMap class
   572 
   573   ///This function just returns an \ref YMap class.
   574   ///
   575   ///\ingroup maps
   576   ///\relates YMap
   577   template<class M> 
   578   inline YMap<M> yMap(M &m) 
   579   {
   580     return YMap<M>(m);
   581   }
   582 
   583   template<class M> 
   584   inline YMap<M> yMap(const M &m) 
   585   {
   586     return YMap<M>(m);
   587   }
   588 
   589   ///Constant (read only) version of \ref YMap
   590 
   591   ///\ingroup maps
   592   ///
   593   template<class M>
   594   class ConstYMap 
   595   {
   596     const M& _map;
   597   public:
   598 
   599     typedef typename M::Value::Value Value;
   600     typedef typename M::Key Key;
   601     ///\e
   602     ConstYMap(const M &map) : _map(map) {}
   603     Value operator[](Key k) const {return _map[k].y;}
   604   };
   605     
   606   ///Returns a \ref ConstYMap class
   607 
   608   ///This function just returns an \ref ConstYMap class.
   609   ///
   610   ///\ingroup maps
   611   ///\relates ConstYMap
   612   template<class M> 
   613   inline ConstYMap<M> yMap(const M &m) 
   614   {
   615     return ConstYMap<M>(m);
   616   }
   617 
   618 
   619   ///Map of the \ref xy::normSquare() "normSquare()" of an \ref xy "xy"-map
   620 
   621   ///Map of the \ref xy::normSquare() "normSquare()" of an \ref xy "xy"-map
   622   ///\ingroup maps
   623   ///
   624   template<class M>
   625   class NormSquareMap 
   626   {
   627     const M& _map;
   628   public:
   629 
   630     typedef typename M::Value::Value Value;
   631     typedef typename M::Key Key;
   632     ///\e
   633     NormSquareMap(const M &map) : _map(map) {}
   634     Value operator[](Key k) const {return _map[k].normSquare();}
   635   };
   636     
   637   ///Returns a \ref NormSquareMap class
   638 
   639   ///This function just returns an \ref NormSquareMap class.
   640   ///
   641   ///\ingroup maps
   642   ///\relates NormSquareMap
   643   template<class M> 
   644   inline NormSquareMap<M> normSquareMap(const M &m) 
   645   {
   646     return NormSquareMap<M>(m);
   647   }
   648 
   649   /// @}
   650 
   651 
   652 } //namespace lemon
   653 
   654 #endif //LEMON_XY_H