src/MadeYourDay/SVG/IconFontGenerator.php
public static function unicodeToHex($char){

		if(!is_string($char) || mb_strlen($char, 'utf-8') !== 1){
			throw new \InvalidArgumentException('$char must be one single character');
		}

		$unicode = unpack('N', mb_convert_encoding($char, 'UCS-4BE', 'UTF-8'));
		return dechex($unicode[1]);

	}
public static function unicodeToHex($char){

		if(!is_string($char) || mb_strlen($char, 'utf-8') !== 1){
			throw new \InvalidArgumentException('$char must be one single character');
		}

		$unicode = unpack('N', mb_convert_encoding($char, 'UCS-4BE', 'UTF-8'));
		return dechex($unicode[1]);

	}
get the unicode hex representation of a unicode character

@param  string $char single character encoded as UTF-8
@return string       unicode hex representation of the character