PHP generates a distorted and angular image verification code function that supports Chinese_PHP tutorial

PHP generates a twisted and angled image verification code function that supports Chinese

function make_rand($length="32"){//Verification code text generation function
$ str="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
$result="";
for($i=0;$i<$length;$i++){
$num[$i]=rand(0,61 );
$result.=$str[$num[$i]];
}
return $result;
}
$checkcode = make_rand(5);
$ im_x=160;
$im_y=32;
function make_crand($length="5") {
$string = '';
for($i=0;$i<$length ;$i++) {
$string .= chr(rand(0xB0,0xF7)).chr(rand(0xA1,0xFE));
}
return $string;
}
function getAuthImage($text , $im_x = 230 , $im_y = 32) {
$im = imagecreatetruecolor($im_x,$im_y);
$text_c = ImageColorAllocate($im, mt_rand(0,100),mt_rand( 0,100),mt_rand(0,100));
$tmpC0=mt_rand(100,255);
$tmpC1=mt_rand(100,255);
$tmpC2=mt_rand(100,255);
$buttum_c = ImageColorAllocate( $im,$tmpC0,$tmpC1,$tmpC2);
imagefill($im, 16, 13, $buttum_c);
//echo $text;
$font = 'c:WINDOWSFontssimsun.ttc ';
//echo strlen($text);

$text=iconv("gb2312","UTF-8",$text);
//echo mb_strlen($text, "UTF-8");
for ($i=0;$i{
$tmp =mb_substr($text,$i,1," UTF-8");
$array = array(-1,0,1);
$p = array_rand($array);
$an = $array[$p]*mt_rand(1 ,9);//Angle
$size = 20;
imagettftext($im,$size,$an,10+$i*$size*2,25,$text_c,$font,$tmp) ;
}

$distortion_im = imagecreatetruecolor ($im_x, $im_y);
imagefill($distortion_im, 16, 13, $buttum_c);
for ( $i=0; $ i<$im_x; $i++) {
for ( $j=0; $j<$im_y; $j++) {
$rgb = imagecolorat($im, $i , $j);
if( (int)($i+20+sin($j/$im_y*2*M_PI)*10) <= imagesx($distortion_im) && (int)($i+20+sin($j/$ im_y*2*M_PI)*10) >=0 ) {
imagesetpixel ($distortion_im, (int)($i+10+sin($j/$im_y*2*M_PI-M_PI*0.5)*3 ), $j, $rgb);
}
}
}
//Add interference pixels;
$count = 600;//The number of interference pixels
for( $i=0; $i<$count; $i++){
$randcolor = ImageColorallocate($distortion_im,mt_rand(0,255),mt_rand(0,255),mt_rand(0,255));
imagesetpixel($distortion_im, mt_rand()%$im_x , mt_rand()%$im_y , $randcolor);
}

$line_c=5;
//imageline
for($i=0; $ i < $line_c; $i++) {
$linecolor = imagecolorallocate($distortion_im, 17, 158, 20);
$lefty = mt_rand(1, $im_x-1);
$righty = mt_rand(1, $im_y-1);
imageline($distortion_im, 0, $lefty, imagesx($distortion_im), $righty, $linecolor);
}

Header("Content -type: image/PNG");

//Output the image to the browser or file in PNG format;
//ImagePNG($im);
ImagePNG($distortion_im);

//Destroy an image and release the memory associated with the image;
ImageDestroy($distortion_im);
ImageDestroy($im);
}

getAuthImage(make_crand( 5));

?>