class Time
{
    constructor()
    {
        this._last_frame = undefined;
        this._current_frame = undefined;
    }

    deltaTime()
    {
        return (this._current_frame - this._last_frame) !== NaN ? this._current_frame - this._last_frame : 0; 
    }

    deltaTimeSecond()
    {
        return this.deltaTime() / 1000;
    }

    get_fps()
    {
        return 1 / this.deltaTimeSecond();
    }

    new_frame()
    {
        this._last_frame = this._current_frame;
        this._current_frame = Date.now();
    }
}

export { Time }