#include <GL/glut.h>
#include <stdlib.h>
#include <math.h>

void display(){
  glClearColor(1,1,1,0);
  glClear(GL_COLOR_BUFFER_BIT);

 glColor3f(1,0,0);
    glBegin(GL_POINTS);
    glPointSize(1);
    GLint i;
    GLfloat theta,r,x,y,pi;

    //upright ball
    theta=0;
    pi=3.141592653589793;
        for(r=3;r>0;r=r-0.1){
      while(theta<=2*pi){
        x=r*cos(theta);
        y=r*sin(theta);
        glVertex2f(x+62,y+63);
        theta=theta+2*pi/1024;
        }
        theta=0;
        }

        glEnd();

  glFlush();
}


int main(int argc, char** argv){
  glutInit(&argc,argv);
  glutInitWindowPosition(50,50);
  glutInitWindowSize(640,640);
  glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);
  glutCreateWindow("Circle");
  glMatrixMode(GL_PROJECTION);
  gluOrtho2D(0,100,0,100);
  glutDisplayFunc(display);
  glutMainLoop();
  return 0;
}