The improvement of the function of outputting Chinese characters in GD

function | Chinese thanks sadly wrote the function of outputting Chinese characters in GD,
I found in the use of this version of the output string must be pure Chinese, can not be mixed in English.
With the modification of this bug, share with you ...

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Program writen by sadly www.phpx.com
Modified by Agun 2000/6/20
function Gb2utf8 ($GB)
{
if (!trim ($GB))
return $GB;
$filename = "Gb2312.txt";
$tmp =file ($filename);
$codetable =array ();
while (list ($key, $value) =each ($tmp))
$codetable [Hexdec (substr ($value, 0,6))]=substr ($value, 7,6);

$ret = "";
$utf 8 = "";
while ($GB)
{
if (Ord (substr ($GB, 0,1)) >127)
{
$this =substr ($GB, 0,2);
$GB =substr ($GB, 2,strlen ($GB));
$utf 8=u2utf8 (Hexdec ($codetable [Hexdec (Bin2Hex ($this)) -0x8080]);
for ($i =0; $i <strlen ($utf 8); $i +=3)
$ret. =CHR (substr ($utf 8, $i, 3));
}
Else
{
$ret. =substr ($GB, 0, 1);
$GB =substr ($GB, 1,strlen ($GB));
}
}
return $ret;
}

function U2utf8 ($c)
{
for ($i =0; $i <count ($c); $i + +)
$str = "";
if ($c < 0x80) {
$str. = $c;
}
else if ($c < 0x800) {
$str. = (0xc0 | $c >>6);
$str. = (0x80 | $c & 0x3F);
}
else if ($c < 0x10000) {
$str. = (0xe0 | $c >>12);
$str. = (0x80 | $c >>6 & 0x3F);
$str. = (0x80 | $c & 0x3F);
}
else if ($c < 0x200000) {
$str. = (0xF0 | $c >>18);
$str. = (0x80 | $c >>12 & 0x3F);
$str. = (0x80 | $c >>6 & 0x3F);
$str. = (0x80 | $c & 0x3F);
}
return $str;
}

Header ("Content-type:image/gif");
$im = Imagecreate (300,150);
$bkg = Imagecolorallocate ($im, 0,0,0);
$CLR = Imagecolorallocate ($im, 255,255,255);
$FNT = "C:\windows\fonts\simsun.ttf";
Include ("gb2utf8.php");
$str = Gb2utf8 ("Chinese agun");
Imagettftext ($im, 0, 50,50, $CLR, $fnt, $STR);
Imagegif ($im);
Imagedestroy ($im);
?>