private static function dec2char($n)
{
// converts a single string representing a decimal number to a character
// note that no checking is performed to ensure that this is just a hex number, eg. no spaces etc
// dec: string, the dec codepoint to be converted
$result = '';
if ($n <= 0xffff) {
$result .= Z_Unicode::fromCharCode($n);
} else {
if ($n <= 0x10ffff) {
$n -= 0x10000;
$result .= Z_Unicode::fromCharCode(0xd800 | $n >> 10) . Z_Unicode::fromCharCode(0xdc00 | $n & 0x3ff);
} else {
throw new Exception('dec2char error: Code point out of range: ' . dechex($n));
}
}
return $result;
}
public static function encodeRelativeDescriptorString($str)
{
if (function_exists('normalizer_normalize')) {
$str = normalizer_normalize($str);
}
$str = Z_Unicode::convertCharStr2UTF8($str);
// convertNumbers2Char($str, 'hex')
$str = preg_replace_callback("/([A-Fa-f0-9]{2})/", function ($matches) {
return Z_Unicode::hex2char($matches[0]);
}, str_replace(" ", "", $str));
return $str;
}
private static function utf8_decode($utftext)
{
$string = "";
$i = 0;
$c = $c1 = $c2 = 0;
while ($i < mb_strlen($utftext)) {
$c = Z_Unicode::charCodeAt($utftext, $i);
if ($c < 128) {
$string .= Z_Unicode::fromCharCode($c);
$i++;
} else {
if ($c > 191 && $c < 224) {
$c2 = Z_Unicode::charCodeAt($utftext, $i + 1);
$string .= Z_Unicode::fromCharCode(($c & 31) << 6 | $c2 & 63);
$i += 2;
} else {
$c2 = Z_Unicode::charCodeAt($utftext, $i + 1);
$c3 = Z_Unicode::charCodeAt($utftext, $i + 2);
$string .= Z_Unicode::fromCharCode(($c & 15) << 12 | ($c2 & 63) << 6 | $c3 & 63);
$i += 3;
}
}
}
return $string;
}
