C Program for DDA Line Drawing Algorithm

#include< stdio.h>
#include< graphics.h>
#include< conio.h>
#define ROUND(a) ((int)(a+0.5))
void DDA_LINE(int x1,int y1,int x2,int y2);
void main()
{
 int x1,y1,x2,y2,gdriver=DETECT,gmode;
 clrscr();
 initgraph(&gdriver,&gmode,"");

 printf("\nEnter point1(x1,y1):");
 scanf("%d %d",&x1,&y1);
 printf("\nEnter point2(x2,y2):");
 scanf("%d %d",&x2,&y2);
 DDA_LINE(x1,y1,x2,y2);
 getch();

}
void DDA_LINE(int x1,int y1,int x2,int y2)
{
 int dx=x2-x1,dy=y2-y1,steps,i;
 float xInc,yInc,x=x1,y=y1;

 if(abs(dx)>abs(dy))
  steps=abs(dx);
 else
  steps=abs(dy);

 xInc=dx/(float)steps;
 yInc=dy/(float)steps;
 putpixel(ROUND(x),ROUND(y),BLACK);

 for(i=0;i< steps;i++)
 {
  x+=xInc;
  y+=yInc;
  putpixel(ROUND(x),ROUND(y),BLACK);
 }

}

OUTPUT