program to draw line using Bresenham’s Algorithm

Code for header file “Myhdr.h”

#include<conio.h>

#include <stdio.h>

#include <dos.h>

#include <graphics.h>

void lB(int x1,int y1,int xn, int yn)

{

int dx,dy,di,ds,dt;

dx = xn - x1,

dy = yn - y1;

di = 2 * dy - dx;

ds = 2 * dy;

dt = 2 * (dy - dx);

putpixel(x1, y1, RED);

while (x1 < xn)

{

x1++;

if (di < 0)

di = di + ds;

else

{

y1++;

di = di + dt;

}

putpixel(x1, y1, RED);

}

} 

 Code For Main Program      

 #include<conio.h>

#include <stdio.h>

#include <dos.h>

#include <graphics.h>

#include"z:Myhdr.h"

void main()

{

int x1, y1, xn, yn;

int gd = DETECT, gm;

initgraph(&gd, &gm, "");

printf("Enter start points of line : ");

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

printf("Enter ending points of line : ");

scanf("%d %d", &xn, &yn);

lB(x1, y1, xn, yn);

getch();

}    

OUTPUT: