C program for drawing a circle using Midpoint Circle Algorithm

/* 

  Midpoint Circle Drawing Algorithm

  Created by: Pirate

*/

#include<stdio.h>

#include<conio.h>

#include<graphics.h>

void pixel(int xc,int yc,int x,int y);

void main()

{

            int gd=DETECT,gm,xc,yc,r,x,y,Pk;

            clrscr();

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

            printf("*** Mid-Point Subdivision algorithm of circle ***\n");

            printf("Enter the value of Xc\t");

            scanf("%d",&xc);

            printf("Enter the value of Yc \t");

            scanf("%d",&yc);

            printf("Enter the Radius of circle\t");

            scanf("%d",&r);

            x=0;

            y=r;

            Pk=1-r;

            pixel(xc,yc,x,y);

            while(x<y)

            {

                        if(Pk<0)

                        {

                                    x=x+1;

                                    Pk=Pk+(2*x)+1;

                        }

                        else

                        {

                                    x=x+1;

                                    y=y-1;

                                    Pk=Pk+(2*x)-(2*y)+1;

                        }

                        pixel(xc,yc,x,y);

            }

            getch();

            closegraph();

}

void pixel(int xc,int yc,int x,int y)

{

            putpixel(xc+x,yc+y,7);

            putpixel(xc+y,yc+x,7);

            putpixel(xc-y,yc+x,7);

            putpixel(xc-x,yc+y,7);

            putpixel(xc-x,yc-y,7);

            putpixel(xc-y,yc-x,7);

            putpixel(xc+y,yc-x,7);

            putpixel(xc+x,yc-y,7);

}







Output