#include "erl_nif.h"
#include "stdio.h"

int test(double real, double imag, int max) {

  long double zr = 0.0;
  long double zi = 0.0;

  long double r = real;
  long double i = imag;

  int depth = 0;
  
  while(depth < max) {
    long double zr2 = zr*zr;
    long double zi2 = zi*zi;
    long double a2 = zr2 + zi2;
    if(a2 < 4.0) {
      depth++;
      zi = 2*zr*zi + i;
      zr = zr2 - zi2 + r;
    } else {
      return depth;
    }
  }
  return 0;
}


static ERL_NIF_TERM test_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
{
    int ret;
    int max;
    double real, imag;

    if (!enif_get_double(env, argv[0], &real)) {
	return enif_make_badarg(env);
    }    

    if (!enif_get_double(env, argv[1], &imag)) {
	return enif_make_badarg(env);
    }    
    
    if (!enif_get_int(env, argv[2], &max)) {
	return enif_make_badarg(env);
    }
    ret = test(real, imag, max);
    return enif_make_int(env, ret);
}


static ErlNifFunc nif_funcs[] = {
    {"test", 3, test_nif},
};

ERL_NIF_INIT(depth, nif_funcs, NULL, NULL, NULL, NULL)