<?php
require 'string.func.php';

$width = 180;
$height = 30;
$image = imagecreatetruecolor ( $width, $height );
$white = imagecolorallocate ( $image, 255, 255, 255 );
$black = imagecolorallocate ( $image, 0, 0, 0 );

imagefilledrectangle ( $image, 1, 1, $width - 2, $height - 2, $white );
$chars = buildRandomString ($type=1, $length=4);
$sess_name = "verify";
$_SESSION [$sess_name] = $chars;
$fontfiles = array (
        "msyh.ttf",
        "msyhbd.ttf",
        "simkai.ttf",
        "SIMLI.TTF",
        "simsun.ttc",
        "SIMYOU.TTF",
        "STXIHEI.TTF",
        "STXINWEI.TTF",
        "STZHONGS.TTF"
);
for($i = 0; $i < $length; $i ++) {
    $size = mt_rand ( 14, 18 );
    $angle = mt_rand ( - 15, 15 );
    $x = 5 + $i * $size;
    $y = mt_rand ( 20, 26 );
    $color = imagecolorallocate ( $image, mt_rand ( 50, 90 ), mt_rand ( 80, 200 ), mt_rand ( 90, 180 ) );
    $fontfile = "../fonts".$fontfiles[mt_rand(0,count($fontfiles)-1)];
    $text = substr($chars,$i,1);
    imagettftext ( $image, $size, $angle, $x, $y, $color, $fontfile, $text );
}
header("content-type:image/gif");
imagegif($image);
imagedestroy($image);