circle using midpoint algorithm and fill colors using boundaryfill algorithm

Draw a circle using midpoint algorithm

and fill colors using boundaryfill algorithm

#include<iostream.h>

#include<conio.h>

#include<math.h>

#include<graphics.h>

void midptcircle(int,int,int);

void boundaryfill(int,int,int,int);

void main()

{

clrscr();

int gd=DETECT,gm;

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

int x1,y1,r;

cout<<"Enter the co-ordinates of the center of the circle:\n\n";

cout<<"x-axis:";

cin>>x1;

cout<<"y-axis:";

cin>>y1;

cout<<"\tEnter the radius of the circle:";

cin>>r;

midptcircle(x1,y1,r);

getch();

}

void midptcircle(int x1,int y1,int r)

{

int x=0;

int y=r;

int p=1-r;

putpixel(x1+x,y1+y,12);

putpixel(x1-x,y1+y,12);

putpixel(x1+x,y1-y,12);

putpixel(x1-x,y1-y,12);

putpixel(x1+y,y1+x,12);

putpixel(x1-y,y1+x,12);

putpixel(x1+y,y1-x,12);

putpixel(x1-y,y1-x,12);

while(x<y)

{

x+=1;

if(p<0)

{

p+=2*x+1;

}

else

{

y-=1;

p+=2*(x-y);

}

putpixel(x1+x,y1+y,12);

putpixel(x1-x,y1+y,12);

putpixel(x1+x,y1-y,12);

putpixel(x1-x,y1-y,12);

putpixel(x1+y,y1+x,12);

putpixel(x1-y,y1+x,12);

putpixel(x1+y,y1-x,12);

putpixel(x1-y,y1-x,12);

}

boundaryfill(x1,y1,5,12);

}

void boundaryfill(int x1,int y1,int fillcolor,int boundarycolor)

{

int c=getpixel(x1,y1);

if((c!=boundarycolor)&&(c!=fillcolor))

{

putpixel(x1,y1,5);

boundaryfill(x1+1,y1,fillcolor,boundarycolor);

boundaryfill(x1-1,y1,fillcolor,boundarycolor);

boundaryfill(x1,y1+1,fillcolor,boundarycolor);

boundaryfill(x1,y1-1,fillcolor,boundarycolor);

}

}

output 

x-axis:200

y-axis:300

     Enter the radius of the circle:50