This is the most popular algorithm in graphics programming.In this c programming is related to graphics programming when you will run this program in you own mechine do not forget to set the path. of you don't the program will not work.

/*
  mid point circle algorithm using C
  
  http://native-code.blogspot.com
  --------------------------------------------
*/

#include<stdio.h>
#include<conio.h>
#include<graphics.h>
#define GPATH "C:\\TC\\BGI"
void mp(int, int, int);
void cpp(int, int, int, int);
void main()
{
int xc, yc, r;
int gd=DETECT, gm;
initgraph(&gd, &gm, GPATH);
printf("\nEnter radius:\n");
scanf("%d", &r);
printf("\nEnter the centre of X and Y:\n");
scanf("%d %d", &xc, &yc);
mp(r, xc, yc);
getch();
}
void mp(int r, int xc, int yc)
{
int x, y, p;
x=0;
y=r;
p=1-r;
cpp(xc, yc, x, y);
while(x<=y)
{
x++;
if(p<0)
p+=2*(x-1);
else
{
p+=2*(x-y)+1;
y--;
}
cpp(xc, yc, x, y);
}
}
void cpp(int xc, int yc, int x, int y)
{
putpixel(xc+x, yc+y, WHITE);
putpixel(xc+y, yc+x, WHITE);
putpixel(xc-x, yc+y, WHITE);
putpixel(xc+y, yc-x, WHITE);
putpixel(xc+x, yc-y, WHITE);
putpixel(xc-y, yc+x, WHITE);
putpixel(xc-x, yc-y, WHITE);
putpixel(xc-y, yc-x, WHITE);
}

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