Program to implement Boundary Fill algorithm in C

/*

   Boundary Fill algorithm

   Created by: Pirate

*/

#include<stdio.h>

#include<conio.h>

#include<graphics.h>

#include<dos.h>

void fill_right(int x,int y);

void fill_left(int x,int y);

void main()

{

                int gd=DETECT,gm,x,y,n,i;

                clrscr();

                initgraph(&gd,&gm,"c:\\turboc3\\bgi");

                printf("*** Boundary Fill algorithm ***");

                /*- draw object -*/

                line (50,50,200,50);

                line (200,50,200,300);

                line (200,300,50,300);

                line (50,300,50,50);

                /*- set seed point -*/

                x=100;   y=100;

                fill_right(x,y);

                fill_left(x-1,y);

                getch();

}

void fill_right(int x,int y)

{

                if((getpixel(x,y) != WHITE)&&(getpixel(x,y) != RED))

                {

                                putpixel(x,y,RED);

                                fill_right(++x,y);   x=x-1;

                                fill_right(x,y-1);

                                fill_right(x,y+1);

                }

                delay(1);

}

void fill_left(int x,int y)

{

                if((getpixel(x,y) != WHITE)&&(getpixel(x,y) != RED))

                {

                                putpixel(x,y,RED);

                                fill_left(--x,y);    x=x+1;

                                fill_left(x,y-1);

                                fill_left(x,y+1);

                }

                delay(1);

}


Output