code: public boolean elapsedTime(int rate, long milli)
      {
          if (started && rate > 0)
          {
              final double frameTime = ONE_SECOND_IN_MILLI / rate;
              return Double.compare(milli, StrictMath.floor(currentTicks * frameTime)) <= 0;
          }
          return false;
      }
docs: Check if specific time has been elapsed (in tick referential).
  
  @param rate The rate reference.
  @param milli The milliseconds to check (based on frame time).
  @return <code>true</code> if time elapsed, <code>false</code> else.
  @throws LionEngineException If invalid argument.