Computer Graphics 2- BRESENHAM’S LINE DRAWING ALGORITHM

#include<stdio.h>
#include<conio.h>
#include<math.h>
#include<graphics.h>
main()
{
int gd=DETECT,gm;
int xa,xb,ya,yb;
int dx,dy,x,y,xend,p;
clrscr();
initgraph(&gd,&gm," ");
printf("enter the left end points(xa,ya):");
scanf("%d%d",&xa,ya);
printf("enter the two right end points(xb,yb):");
scanf("%d%d",&xb,&yb);
dx=abs(xa-xb);
dy=abs(ya-yb);
p=2*dy-dx;
if(xa>xb)
{
x=xb;
y=yb;
xend=xa;
}
else
{
x=xa;
y=ya;
xend=xb;
}
putpixel(x,y,6);
while(x<xend)
{
x=x+1;
if(p<0)
{
p=p+2*dy;
}
else
{
y=y+1;
p=p+2*(dy-dx);
}
putpixel(x,y,6);
}
getch();
return 0;
}