protected function doCaptcha()
{
//Generate a number and save it in session
$sCaptcha = (string) rand(1000, 9999);
//replace "1" or "7" as it's difficult to make the difference
for ($i = 0; $i < strlen($sCaptcha); $i++) {
if ($sCaptcha[$i] == "1" || $sCaptcha[$i] == "7") {
$sCaptcha[$i] = (string) rand(2, 6);
}
}
AnwCurrentSession::setCaptcha($sCaptcha);
//captcha settings
$nMaxAngle = 20;
$nFontSizeMin = 13;
$nFontSizeMax = 14;
$height = 20;
$width = 80;
$nCharSpace = 17;
$font = ANWPATH_LIB . 'fonts/lazy_dog.ttf';
$nNoisePxMin = 20;
$nNoisePxMax = 40;
header("Content-type: image/png");
//Create image
$im = imagecreate($width, $height);
imagecolorallocate($im, 255, 255, 255);
//white background
//write numbers
$len = strlen($sCaptcha);
$x = 10;
for ($i = 0; $i < $len; $i++) {
$nTmpAngle = rand(0, 1) == 1 ? rand(0, $nMaxAngle) : rand(360 - $nMaxAngle, 360);
//random angle
$nTmpSize = rand($nFontSizeMin, $nFontSizeMax);
//random size
$nTmpTop = $height * 0.8 + rand(0, $height / 8);
//random position from top
$nTmpColor = imagecolorallocate($im, rand(0, 210), rand(0, 210), rand(0, 210));
//random color
imagettftext($im, $nTmpSize, $nTmpAngle, $x, $nTmpTop, $nTmpColor, $font, $sCaptcha[$i]);
$x += $nCharSpace;
}
//add noise
$nbpx = rand($nNoisePxMin, $nNoisePxMax);
for ($i = 1; $i < $nbpx; $i++) {
$color = imagecolorallocate($im, rand(0, 255), rand(0, 255), rand(0, 255));
imagesetpixel($im, rand(0, $width - 1), rand(0, $height - 1), $color);
}
//Output image
imagepng($im);
imagedestroy($im);
exit;
}
