# HG changeset patch
# User kpeter
# Date 1202210603 0
# Node ID 27c54b7f4f1d507c0835dd4e8fcde74233917878
# Parent  ec5c56f0501e951ac38df3167051488246419398
Improvements and fixes in dim2.h.

- Several doc improvements.
- Fix BoundingBox::operator& implementation.

diff -r ec5c56f0501e -r 27c54b7f4f1d lemon/dim2.h
--- a/lemon/dim2.h	Tue Feb 05 11:10:08 2008 +0000
+++ b/lemon/dim2.h	Tue Feb 05 11:23:23 2008 +0000
@@ -52,9 +52,7 @@
   /// A simple two dimensional vector (plainvector) implementation
 
   /// A simple two dimensional vector (plainvector) implementation
-  ///with the usual vector
-  /// operators.
-  ///
+  /// with the usual vector operations.
   template<typename T>
     class Point {
 
@@ -62,9 +60,9 @@
 
       typedef T Value;
 
-      ///First co-ordinate
+      ///First coordinate
       T x;
-      ///Second co-ordinate
+      ///Second coordinate
       T y;     
       
       ///Default constructor
@@ -75,7 +73,7 @@
 
       ///The dimension of the vector.
 
-      ///This class give back always 2.
+      ///This function always returns 2.
       ///
       int size() const { return 2; }
 
@@ -99,14 +97,14 @@
         return x*x+y*y;
       }
   
-      ///Increment the left hand side by u
+      ///Increment the left hand side by \c u
       Point<T>& operator +=(const Point<T>& u) {
         x += u.x;
         y += u.y;
         return *this;
       }
   
-      ///Decrement the left hand side by u
+      ///Decrement the left hand side by \c u
       Point<T>& operator -=(const Point<T>& u) {
         x -= u.x;
         y -= u.y;
@@ -138,7 +136,7 @@
         return b+=u;
       }
 
-      ///Return the neg of the vectors
+      ///Return the negative of the vector
       Point<T> operator-() const {
         Point<T> b=*this;
         b.x=-b.x; b.y=-b.y;
@@ -175,9 +173,9 @@
 
     };
 
-  ///Return an Point 
+  ///Return a Point 
 
-  ///Return an Point
+  ///Return a Point.
   ///\relates Point
   template <typename T>
   inline Point<T> makePoint(const T& x, const T& y) {
@@ -286,9 +284,11 @@
       
       ///Construct an instance from two points
       
-      ///Construct an instance from two points
-      ///\warning The coordinates of the bottom-left corner must be no more
-      ///than those of the top-right one
+      ///Construct an instance from two points.
+      ///\param a The bottom left corner.
+      ///\param b The top right corner.
+      ///\warning The coordinates of the bottom left corner must be no more
+      ///than those of the top right one.
       BoundingBox(Point<T> a,Point<T> b)
       {
 	bottom_left=a;
@@ -298,9 +298,13 @@
       
       ///Construct an instance from four numbers
 
-      ///Construct an instance from four numbers
-      ///\warning The coordinates of the bottom-left corner must be no more
-      ///than those of the top-right one
+      ///Construct an instance from four numbers.
+      ///\param l The left side of the box.
+      ///\param b The bottom of the box.
+      ///\param r The right side of the box.
+      ///\param t The top of the box.
+      ///\warning The left side must be no more than the right side and
+      ///bottom must be no more than the top. 
       BoundingBox(T l,T b,T r,T t)
       {
 	bottom_left=Point<T>(l,b);
@@ -308,7 +312,13 @@
 	_empty = false;
       }
       
-      ///Were any points added?
+      ///Return \c true if the bounding box is empty.
+      
+      ///Return \c true if the bounding box is empty (i.e. return \c false
+      ///if at least one point was added to the box or the coordinates of
+      ///the box were set).
+      ///
+      ///The coordinates of an empty bounding box are not defined. 
       bool empty() const {
         return _empty;
       }
@@ -318,67 +328,67 @@
         _empty=1;
       }
 
-      ///Give back the bottom left corner
+      ///Give back the bottom left corner of the box
 
-      ///Give back the bottom left corner.
+      ///Give back the bottom left corner of the box.
       ///If the bounding box is empty, then the return value is not defined.
       Point<T> bottomLeft() const {
         return bottom_left;
       }
 
-      ///Set the bottom left corner
+      ///Set the bottom left corner of the box
 
-      ///Set the bottom left corner.
-      ///It should only bee used for non-empty box.
+      ///Set the bottom left corner of the box.
+      ///It should only be used for non-empty box.
       void bottomLeft(Point<T> p) {
 	bottom_left = p;
       }
 
-      ///Give back the top right corner
+      ///Give back the top right corner of the box
 
-      ///Give back the top right corner.
+      ///Give back the top right corner of the box.
       ///If the bounding box is empty, then the return value is not defined.
       Point<T> topRight() const {
         return top_right;
       }
 
-      ///Set the top right corner
+      ///Set the top right corner of the box
 
-      ///Set the top right corner.
-      ///It should only bee used for non-empty box.
+      ///Set the top right corner of the box.
+      ///It should only be used for non-empty box.
       void topRight(Point<T> p) {
 	top_right = p;
       }
 
-      ///Give back the bottom right corner
+      ///Give back the bottom right corner of the box
 
-      ///Give back the bottom right corner.
+      ///Give back the bottom right corner of the box.
       ///If the bounding box is empty, then the return value is not defined.
       Point<T> bottomRight() const {
         return Point<T>(top_right.x,bottom_left.y);
       }
 
-      ///Set the bottom right corner
+      ///Set the bottom right corner of the box
 
-      ///Set the bottom right corner.
-      ///It should only bee used for non-empty box.
+      ///Set the bottom right corner of the box.
+      ///It should only be used for non-empty box.
       void bottomRight(Point<T> p) {
 	top_right.x = p.x;
 	bottom_left.y = p.y;
       }
  
-      ///Give back the top left corner
+      ///Give back the top left corner of the box
 
-      ///Give back the top left corner.
+      ///Give back the top left corner of the box.
       ///If the bounding box is empty, then the return value is not defined.
       Point<T> topLeft() const {
         return Point<T>(bottom_left.x,top_right.y);
       }
 
-      ///Set the top left corner
+      ///Set the top left corner of the box
 
-      ///Set the top left corner.
-      ///It should only bee used for non-empty box.
+      ///Set the top left corner of the box.
+      ///It should only be used for non-empty box.
       void topLeft(Point<T> p) {
 	top_right.y = p.y;
 	bottom_left.x = p.x;
@@ -395,7 +405,7 @@
       ///Set the bottom of the box
 
       ///Set the bottom of the box.
-      ///It should only bee used for non-empty box.
+      ///It should only be used for non-empty box.
       void bottom(T t) {
 	bottom_left.y = t;
       }
@@ -411,7 +421,7 @@
       ///Set the top of the box
 
       ///Set the top of the box.
-      ///It should only bee used for non-empty box.
+      ///It should only be used for non-empty box.
       void top(T t) {
 	top_right.y = t;
       }
@@ -427,7 +437,7 @@
       ///Set the left side of the box
 
       ///Set the left side of the box.
-      ///It should only bee used for non-empty box
+      ///It should only be used for non-empty box.
       void left(T t) {
 	bottom_left.x = t;
       }
@@ -443,7 +453,7 @@
       ///Set the right side of the box
 
       ///Set the right side of the box.
-      ///It should only bee used for non-empty box
+      ///It should only be used for non-empty box.
       void right(T t) {
 	top_right.x = t;
       }
@@ -465,7 +475,7 @@
       }
 
       ///Checks whether a point is inside a bounding box
-      bool inside(const Point<T>& u){
+      bool inside(const Point<T>& u) const {
         if (_empty)
           return false;
         else{
@@ -475,6 +485,9 @@
       }
   
       ///Increments a bounding box with a point
+
+      ///Increments a bounding box with a point.
+      ///
       BoundingBox& add(const Point<T>& u){
         if (_empty){
           bottom_left=top_right=u;
@@ -489,7 +502,10 @@
         return *this;
       }
     
-      ///Increments a bounding to contain another bounding box
+      ///Increments a bounding box to contain another bounding box
+      
+      ///Increments a bounding box to contain another bounding box.
+      ///
       BoundingBox& add(const BoundingBox &u){
         if ( !u.empty() ){
           this->add(u.bottomLeft());
@@ -499,24 +515,31 @@
       }
   
       ///Intersection of two bounding boxes
-      BoundingBox operator &(const BoundingBox& u){
+
+      ///Intersection of two bounding boxes.
+      ///
+      BoundingBox operator&(const BoundingBox& u) const {
         BoundingBox b;
-	b.bottom_left.x=std::max(this->bottom_left.x,u.bottom_left.x);
-	b.bottom_left.y=std::max(this->bottom_left.y,u.bottom_left.y);
-	b.top_right.x=std::min(this->top_right.x,u.top_right.x);
-	b.top_right.y=std::min(this->top_right.y,u.top_right.y);
-	b._empty = this->_empty || u._empty ||
-	  b.bottom_left.x>top_right.x && b.bottom_left.y>top_right.y;
+        if (this->_empty || u._empty) {
+	  b._empty = true;
+	} else {
+	  b.bottom_left.x=std::max(this->bottom_left.x,u.bottom_left.x);
+	  b.bottom_left.y=std::max(this->bottom_left.y,u.bottom_left.y);
+	  b.top_right.x=std::min(this->top_right.x,u.top_right.x);
+	  b.top_right.y=std::min(this->top_right.y,u.top_right.y);
+	  b._empty = b.bottom_left.x > b.top_right.x ||
+	             b.bottom_left.y > b.top_right.y;
+	} 
         return b;
       }
 
     };//class Boundingbox
 
 
-  ///Map of x-coordinates of a dim2::Point<>-map
+  ///Map of x-coordinates of a \ref Point "Point"-map
 
   ///\ingroup maps
-  ///Map of x-coordinates of a dim2::Point<>-map
+  ///Map of x-coordinates of a \ref Point "Point"-map.
   ///
   template<class M>
   class XMap 
@@ -570,7 +593,7 @@
     
   ///Returns a \ref ConstXMap class
 
-  ///This function just returns an \ref ConstXMap class.
+  ///This function just returns a \ref ConstXMap class.
   ///
   ///\ingroup maps
   ///\relates ConstXMap
@@ -580,10 +603,10 @@
     return ConstXMap<M>(m);
   }
 
-  ///Map of y-coordinates of a dim2::Point<>-map
+  ///Map of y-coordinates of a \ref Point "Point"-map
     
   ///\ingroup maps
-  ///Map of y-coordinates of a dim2::Point<>-map
+  ///Map of y-coordinates of a \ref Point "Point"-map.
   ///
   template<class M>
   class YMap 
@@ -599,9 +622,9 @@
     void set(Key k,Value v) {_map.set(k,typename M::Value(_map[k].x,v));}
   };
 
-  ///Returns an \ref YMap class
+  ///Returns a \ref YMap class
 
-  ///This function just returns an \ref YMap class.
+  ///This function just returns a \ref YMap class.
   ///
   ///\ingroup maps
   ///\relates YMap
@@ -637,7 +660,7 @@
     
   ///Returns a \ref ConstYMap class
 
-  ///This function just returns an \ref ConstYMap class.
+  ///This function just returns a \ref ConstYMap class.
   ///
   ///\ingroup maps
   ///\relates ConstYMap
@@ -648,12 +671,12 @@
   }
 
 
-    ///\brief Map of the \ref Point::normSquare() "normSquare()"
-    ///of an \ref Point "Point"-map
-    ///
-    ///Map of the \ref Point::normSquare() "normSquare()"
-    ///of an \ref Point "Point"-map
-    ///\ingroup maps
+  ///\brief Map of the \ref Point::normSquare() "normSquare()"
+  ///of a \ref Point "Point"-map
+  ///
+  ///Map of the \ref Point::normSquare() "normSquare()"
+  ///of a \ref Point "Point"-map.
+  ///\ingroup maps
     ///
   template<class M>
   class NormSquareMap 
@@ -670,7 +693,7 @@
     
   ///Returns a \ref NormSquareMap class
 
-  ///This function just returns an \ref NormSquareMap class.
+  ///This function just returns a \ref NormSquareMap class.
   ///
   ///\ingroup maps
   ///\relates NormSquareMap