Write a program to implement Liang-Bersky line clipping algorithm code example

Example: Write a program to implement Liang-Bersky line clipping algorithm

#include
#include
#include
#include
 
void main()
{
	int i,gd=DETECT,gm;
	int x1,y1,x2,y2,xmin,xmax,ymin,ymax,xx1,xx2,yy1,yy2,dx,dy;
	float t1,t2,p[4],q[4],temp;
	
	x1=120;
	y1=120;
	x2=300;
	y2=300;
	
	xmin=100;
	ymin=100;
	xmax=250;
	ymax=250;
	
	initgraph(&gd,&gm,"c:\\turboc3\\bgi");
	rectangle(xmin,ymin,xmax,ymax);
	dx=x2-x1;
	dy=y2-y1;
	
	p[0]=-dx;
	p[1]=dx;
	p[2]=-dy;
	p[3]=dy;
	
	q[0]=x1-xmin;
	q[1]=xmax-x1;
	q[2]=y1-ymin;
	q[3]=ymax-y1;
	
	for(i=0;i<4;i++)
	{
		if(p[i]==0)
		{
			cout<<"line is parallel to one of the clipping boundary";
			if(q[i]>=0)
			{
				if(i<2)
				{
					if(y1ymax)
					{
						y2=ymax;
					}
				
					line(x1,y1,x2,y2);
				}
				
				if(i>1)
				{
					if(x1xmax)
					{
						x2=xmax;
					}
					
					line(x1,y1,x2,y2);
				}
			}
		}
	}
	
	t1=0;
	t2=1;
	
	for(i=0;i<4;i++)
	{
		temp=q[i]/p[i];
		
		if(p[i]<0)
		{
			if(t1<=temp)
				t1=temp;
		}
		else
		{
			if(t2>temp)
				t2=temp;
		}
	}
	
	if(t1