source: lemon-0.x/src/work/athos/xy/boundingbox.h @ 240:4a1d2e642552

// -*- c++ -*-
/**
Implementation of a bounding box of plainvectors.

*/
#ifndef HUGO_BOUNDINGBOX_H
#define HUGO_BOUNDINGBOX_H


#include <xy.h>

namespace hugo {

  template<typename T>
    class BoundingBox {
      xy<T> bottomleft, topright;
      bool _empty;
    public:
      
      ///Default constructor: an empty bounding box
      BoundingBox() { _empty = true; }

      ///Constructing the instance from one point
      BoundingBox(xy<T> a) { bottomleft=topright=a; _empty = false; }

      ///Is there any point added
      bool empty() const {
        return _empty;
      }

      ///Gives back the bottom left corner (if the bounding box is empty, then the return value is not defined) 
      xy<T> bottomLeft() const {
        return bottomleft;
      };

      ///Gives back the top right corner (if the bounding box is empty, then the return value is not defined) 
      xy<T> topRight() const {
        return topright;
      };

      ///Checks whether a point is inside a bounding box
      bool inside(const xy<T>& u){
        if (_empty)
          return false;
        else{
          return ((u.x-bottomleft.x)*(topright.x-u.x) >= 0 &&
                  (u.y-bottomleft.y)*(topright.y-u.y) >= 0 );
        }
      }
  
      ///Increments a bounding box with a point
      BoundingBox& operator +=(const xy<T>& u){
        if (_empty){
          bottomleft=topright=u;
          _empty = false;
        }
        else{
          if (bottomleft.x > u.x) bottomleft.x = u.x;
          if (bottomleft.y > u.y) bottomleft.y = u.y;
          if (topright.x < u.x) topright.x = u.x;
          if (topright.y < u.y) topright.y = u.y;
        }
        return *this;
      };
  
      ///Sums a bounding box and a point
      BoundingBox operator +(const xy<T>& u){
        BoundingBox b = *this;
        return b += u;
      };

      ///Increments a bounding box with an other bounding box
      BoundingBox& operator +=(const BoundingBox &u){
        if ( !u.empty() ){
          *this += u.bottomLeft();
          *this += u.topRight();
        }
        return *this;
      };
  
      ///Sums two bounding boxes
      BoundingBox operator +(const BoundingBox& u){
        BoundingBox b = *this;
        return b += u;
      };

    };//class BoundingBox


} //namespace hugo

#endif //HUGO_BOUNDINGBOX_H