Seed Fill

/*

 * THIS IS A C PROGRAM THAT IMPLEMENTS SEED FILL ALGORITHM

 */

#include<stdio.h>

#include<graphics.h>

#include<math.h>

#include<stdlib.h>

#include<conio.h>

#include<dos.h>

#define MAXST 2048

#define BOUNDARY_COLOR BLACK

#define FILL_COLOR DARKGRAY

typedef struct

{

 int x,y;

}Pixel;

struct stack_t{

            int top;

            Pixel val[MAXST];

};

typedef struct stack_t *stack;

stack s_create(){

            stack p;

            p=(stack)malloc(sizeof(struct stack_t));

            if(p==NULL){

             exit(0);

            }

            p->top=-1;

            return p;

}

int s_empty(stack s){

            if(s->top==-1)

                        return 1;

            else return 0;

}

void push(stack s,Pixel e){

            s->val[++(s->top)]=e;

}

Pixel pop(stack s){

            if(!(s_empty(s)))

                        return s->val[(s->top)--];

}

void seedfill(Pixel seed)

{ 

   stack s=s_create();

   Pixel pixel=seed,temppixel;

   push(s,pixel);

   setcolor(FILL_COLOR);

   while(!s_empty(s))

   {

     pixel=pop(s);

     if(getpixel(pixel.x,pixel.y)!=BOUNDARY_COLOR && getpixel(pixel.x,pixel.y)!=FILL_COLOR)

      putpixel(pixel.x,pixel.y,FILL_COLOR);

     if(getpixel(pixel.x+1,pixel.y)!=BOUNDARY_COLOR && getpixel(pixel.x+1,pixel.y)!=FILL_COLOR)

     {

      temppixel=pixel;

      temppixel.x++;

      push(s,temppixel);

     }

     if(getpixel(pixel.x,pixel.y+1)!=BOUNDARY_COLOR && getpixel(pixel.x,pixel.y+1)!=FILL_COLOR)

     {

      temppixel=pixel;

      temppixel.y=temppixel.y+1;

      push(s,temppixel);

     }

     if(getpixel(pixel.x-1,pixel.y)!=BOUNDARY_COLOR && getpixel(pixel.x-1,pixel.y)!=FILL_COLOR)

     {

      temppixel=pixel;

      temppixel.x=temppixel.x-1;

      push(s,temppixel);

     }

     if(getpixel(pixel.x,pixel.y-1)!=BOUNDARY_COLOR && getpixel(pixel.x,pixel.y-1)!=FILL_COLOR)

     {

      temppixel=pixel;

      temppixel.y=temppixel.y-1;

      push(s,temppixel);

     }

     delay(5);

   }

}

void main(){

            int x,y,r,originx,originy;

            int gdriver=DETECT,gmode,i=0;

            char msg[80];

            Pixel seed;

            seed.x=150;

            seed.y=150;

            int poly[10]={100,100,100,200,200,200,200,100,100,100};

            //initialize the graphics support

            initgraph(&gdriver,&gmode,"c:\\tc\\bgi"); doit();

            setcolor(BOUNDARY_COLOR);

            setlinestyle(SOLID_LINE,2,3);

            drawpoly(5,poly);

            seedfill(seed);

            getch();

}