C PROGRAM TO DESIGN A MOVING WHEEL

/* C PROGRAM TO  DESIGN  A MOVING WHEEL                 */
/* AUTHOR : DEEPAK MAHAKALE 3RD YEAR IT SRCOEM, NAGPUR  */

#include<stdio.h>
#include<graphics.h>
#include<math.h>
#include<conio.h>
#include<dos.h>

int xc = 50, yc = 200, r = 35;
int x[15], y[15];
void drawcircles() {
  setcolor(YELLOW);
  circle(xc, yc, r);
  circle(xc, yc, r + 5);
}
void main() {
  double angle = 0, theta;
  int i, a;
  int gd = DETECT, gm;
  initgraph( & gd, & gm, "C:\TC\BGI");
  a = xc + r;
  while (!kbhit()) {
    while (a <= 630) {
      theta = M_PI * angle / 180;
      cleardevice();
      drawcircles();
      for (i = 0; i < 18; i++) {
        theta = M_PI * angle / 180;
        x[i] = xc + r * cos(theta);
        y[i] = yc + r * sin(theta);
        angle += 20;
        line(xc, yc, x[i], y[i]);
      }
      angle += 2;
      xc += 2;
      a = xc + r;
      delay(50);
    }
    xc = 50;
    r = 35;
    a = xc + r;
  }
  getch();
  closegraph();
}