// ------------------------------------------------------------------------
  // This program is complementary material for the book:
  //
  // Frank Nielsen
  //
  // Visual Computing: Geometry, Graphics, and Vision
  //
  // ISBN: 1-58450-427-7
  //
  // Charles River Media, Inc.
  //
  //
  // All programs are available at www.charlesriver.com/visualcomputing/
  //
  // You may use this program for ACADEMIC and PERSONAL purposes ONLY. 
  //
  //
  // The use of this program in a commercial product requires EXPLICITLY
  // written permission from the author. The author is NOT responsible or 
  // liable for damage or loss that may be caused by the use of this program. 
  //
  // Copyright (c) 2005. Frank Nielsen. All rights reserved.
  // ------------------------------------------------------------------------
   
  // ------------------------------------------------------------------------
  // File: genericdictionary.cpp
  // 
  // Description: sample program that shows the use of a templated dictionary
  // ------------------------------------------------------------------------
  
  include <stdafx.h>
  
  using namespace std;
  
  class point {
  public:
  double x,y;
  };
  
  class segment {
  public:
  point A,B;
  };
  
  class Yline {
  public:
  static double x;
  
  double a,b; // equation of nonvertical line y=ax+b
  
  // Overloading
  bool operator <  ( const Yline &  rhs)
  {
          cout <<"\n\t\tGeneric dictionary (inferior): "<<x<<endl;
          cout <<"\t\t"<<a*x+b<<"<"<<rhs.a*x+b<<"?"<<endl;
  
          return (a*x+b<rhs.a*x+rhs.b);}
  
  };
  
  double Yline::x;
  
  // Line equation + segment number
  void SegmentToYevent(segment S,  Yline& eventp)
  {
          eventp.a=(S.B.y-S.A.y)/(S.B.x-S.A.x); //slope
          eventp.b=S.A.y-eventp.a*S.A.x; // y=ax+b
  }
  
  int _tmain(int argc, _TCHAR* argv[])
  {
  segment seg1, seg2;
  Yline lseg1, lseg2;
          
          srand(2005);
  
  cout<<"Visual Computing: Geometry, Graphics, and Vision (ISBN:1-58450-427-7)"<<endl;
  cout<<"Demo program\n\n"<<endl;
  
  seg1.A.x=0;seg1.A.y=0;
  seg1.B.x=1.0;seg1.B.y=1.0;
  
  seg2.A.x=0;seg2.A.y=1;
  seg2.B.x=1.0;seg2.B.y=0.0;
  
  SegmentToYevent(seg1,lseg1);
  SegmentToYevent(seg2,lseg2);
  
  cout<<"I created two line segments (diagonals of the unit square)."<<endl;
  cout<<"The associated line equations are:"<<endl;
  cout<<"lseg1: y="<<lseg1.a<<"x+"<<lseg1.b<<"=0."<<endl;
  cout<<"lseg2: y="<<lseg2.a<<"x+"<<lseg2.b<<"=0."<<endl;
  
  Yline::x=0.25;
  
  if (lseg1<lseg2) cout<<"segment 1 is below segment 2";
                                  else
                                  cout<<"segment 1 is above segment 2";
  
  Yline::x=0.75;
  
  if (lseg1<lseg2) cout<<"segment 1 is below segment 2";
                                  else
                                   cout<<"segment 1 is above segment 2";
  
  cout<<"\n\nPress Return key"<<endl;
  char line[100];
  gets(line);
  
          return 0;
  }