<?php
header("Content-Type: text/plain; charset=utf-8");
?> 
<?php

error_reporting(-1);
mb_internal_encoding('utf-8');
$text = 'В российском сегменте';


$len          = mb_strlen($text);
$circleRadius = $len / 2.5;
$txt          = preg_split("//u", $text, null, PREG_SPLIT_NO_EMPTY);


$screen = array();
for ($i = 0; $i <= $len * 4; $i++) {
    for ($k = 0; $k <= $len * 4; $k++) {
        $screen[$i][$k] = ' ';
    }
    
}

$corners = array();
$corner  = round(360 / $len, 2);
$c       = $corner;


$i = 0;
foreach ($txt as $letter) {
    
    $x = (round(cos($c * M_PI / 180) * $circleRadius) + $circleRadius) * 2.4;
    $y = round(sin($c * M_PI / 180) * $circleRadius) + $circleRadius;
    
    
    $screen[$y][$x] = $letter;
    
    $c += $corner;
    
}
foreach ($screen as $v) {
    
    echo implode("", $v) . "\n";
    
}