COHEN SUTHERLAND line clipping code in C++

COHEN SUTHERLAND line clipping code in C++

Here is my own generated code for Cohen Sutherland line clipping algorithm in C++.Hope its useful for you.

Any suggestions to improve the code are welcomed.
Note:Here the xl,yl,xh and yh are assumed as shown in figure below:

This is different to the dimensioning done on the screen.

Source Code:

#include<iostream.h>
#include<conio.h>
# include<graphics.h>
void main(){
int gd=DETECT,gm;
initgraph(&gd,&gm,"C:\\TC\\BGI");
int xl,xh,yl,yh,bit1,bit2,i,x1,y1,x2,y2,b3,b4,b1,b2,d,e;
float m;
cout<<"Enter the lower window co-ordinates";
cin>>xl>>yl;
cout<<"Enter higher window co-ordinates";
cin>>xh>>yh;
rectangle(xl,yl,xh,yh);
cout<<"\n Enter the two end-points of line:";
cout<<"x1:";
cin>>x1;
cout<<"y1:";
cin>>y1;
cout<<"x2:";
cin>>x2;
cout<<"y2:";
cin>>y2;
line(x1,y1,x2,y2);
//for 1st end-point
if(x1<xl && y1>yl)
bit1=5;
else
if(x1<xl && y1>yh && y1<yl)
bit1=1;
else
if(x1<xl && y1<yh)
bit1=9;
else
if(x1>xl && x1<xh && y1<yh)
bit1=8;
else
if(x1>xh && y1<yh)
bit1=10;
else
if(x1>xh && y1>yh && y1<yl)
bit1=2;
else
if(x1>xh && y1>yl)
bit1=6;
else
if(x1<xh && x1>xl && y1>yl)
bit1=4;
else
{bit1=0;}
//for 2nd end point
if(x2<xl && y2>yl)
bit2=5;
else
if(x2<xl && y2>yh && y2<yl)
bit2=1;
else
if(x2<xl && y2<yh)
bit2=9;
else
if(x2>xl && x2<xh && y2<yh)
bit2=8;
else
if(x2>xh && y2<yh)
bit2=10;
else
if(x2>xh && y2>yh && y2<yl)
bit2=2;
else
if(x2>xh && y2>yl)
bit2=6;
else
if(x2<xh && x2>xl && y2>yl)
bit2=4;
else
{bit2=0;}

m=(float)(y2-y1)/(x2-x1);
 b1=m*(xl-x1)+y1;
b2=m*(xh-x1)+y1;
 d=yh-y1;
 e=yl-y1;
 b3=x1+(d/m);
 b4=x1+(e/m);
if(bit1!=0 || bit2!=0)
{setcolor(46);
 if(b1<=yl && b1>=yh && b2<=yl && b2 >=yh)
  line(xl,b1,xh,b2);
else
 if(b1<=yl && b1>=yh && b3<=xh && b3 >=xl)
  line(xl,b1,b3,yh);
else
 if(b1<=yl && b1>=yh && b4<=xh && b4 >=xl)
  line(xl,b1,b4,yl);
else
 if(b2<=yl && b2>=yh && b3<=xh && b3>=xl)
  line(xh,b2,b3,yh);
else
 if(b2<=yl && b2>=yh && b4<=xh && b4 >=xl)
  line(xh,b2,b4,yl);
else
 if( b3<=xh && b3>=xl && b4<=xh && b4>=xl)
  line(b3,yh,b4,yl);
}
else
{cout<<"line lies inside the window";  }
getch();
}

OUTPUT: