Digital Difference algorithm (DDA)

#include<stdio.h>
#include<conio.h>
#include<graphics.h>
void main ()
{
int i,x,y,x0,y0,x1,y1;

float m;

int gd=DETECT,gm;

initgraph (&gd,&gm,"c:\\tc\\bgi");

printf ("\n Enter the starting point");

scanf ("%d%d",&x0,&y0);

printf ("\n Enter the end point");

scanf ("%d%d",&x1,&y1);

putpixel (x0,y0,5);

m=((y1-y0)/(x1-x0));

x=x0;

y=y0;

if (m<=1)

{

while (x<=x1)

{

x=x+1;

y=y+m;

putpixel (x,floor (y+0.5),6);

}

}

else 

{

while (y<=y1)

{

y=y+1;

x=y*m;

putpixel (floor(x+0.5),y,5);

}

}

getch ();

closegraph();

}