#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "GrWin.h"

int main()
{
  float x[10], y[10], dy[10], w=10.0;
  int i, c=10, seed;

  printf("random seed = ");
  scanf("%d",&seed);
  srand(seed); 

  GWopen(0);
  GWindow(0.0, 0.0, 200.0, 200.0);

  for(i=0; i<10; i++) {
    x[i]=(float)(rand()%200);
  	y[i]=(float)(rand()%180)+20.0;
  	dy[i]=(float)(rand()% (int)(w/2.0) )+w/4.0;
  }
  while(1) { 
  	GWclear(-1);
    for(i=0; i<10; i++) {
      GWscircle(x[i], y[i], x[i]+w*0.7, y[i]+w, c);
  	  y[i]-=dy[i];
  	  if(y[i]<10.0) {
  	    x[i]=(float)(rand()%200);
  	    y[i]=200.0;
  	  }
    }
  	GWsleep(30);
  }

}