C Program to implement Bresenham’s Line Drawing Algorithm

#include<graphics.h>

#include<conio.h>

#include<math.h>

void bresenham_algo(int,int,int,int);

void main()

{

 int gd=DETECT,gmode,xa,ya,xb,yb;

 initgraph(&gd,&gmode,"c:\\tc\\bgi");

 printf("Enter first co-ordinates:");

 scanf("%d %d",&xa,&ya);

 printf("\nEnter second co-ordinates:");

 scanf("%d %d",&xb,&yb);

 bresenham_algo(xa,xb,ya,yb);

 getch();

}

void bresenham_algo(int xa,int ya,int xb,int yb)

{

 int dx,dy,x,y,xend,p;

 dx=abs(xa-xb);

 dy=abs(ya-yb);

 p=(2*dy)-dx;

 if(xa<xb)

 {

  x=xa;

  y=ya;

  xend=xb;

 }

 else

 {

  x=xb;y=yb;xend=xa;

 }

 putpixel(x,y,7);

 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,7);

 }

}

OUTPUT: