Use of Undefined Constant

Question

Well I was in the same trouble of that question, gave an answer to use define('ROOT_PATH', dirname(__FILE__));, (my problem without using this solution) but in mine it does not work.
The following error is shown::

Warning: Use of Undefined Constant DIRETORIO - assumed 'DIRETORIO' (this will throw an Error in a Future version of PHP) in C: wamp64 www php_pdo view Sign-in.php on line 27

index php.:

    <php   
    define('DIRETORIO', dirname(__DIR__));
    ...

Sign-in.php:

<?php
    if($_POST){
        $usuario = filter_input(INPUT_POST, 'usuario', FILTER_SANITIZE_STRING);
        $senha = filter_input(INPUT_POST, 'senha', FILTER_SANITIZE_STRING);

        require_once DIRETORIO . '/controller/logincontroller.php'; // linha 27
        LoginController::logar($usuario, $senha);

    }

I tried to do what that answer suggests, but gave in the same.

Sign-in.php

<?php
    if($_POST){
        $usuario = filter_input(INPUT_POST, 'usuario', FILTER_SANITIZE_STRING);
        $senha = filter_input(INPUT_POST, 'senha', FILTER_SANITIZE_STRING);
        require_once '../index.php';
        require_once DIRETORIO . '/controller/logincontroller.php'; // linha 27
        LoginController::logar($usuario, $senha);

    }