Пример класса captcha на php (3)

/******************************************************************

  Projectname:  CAPTCHA class
  Version:    2.0
  Author:    Pascal Rehfeldt <Pascal@Pascal-Rehfeldt.com>
  Last modified: 15. January 2006

  * GNU General Public License (Version 2, June 1991)
  *
  * This program is free software; you can redistribute
  * it and/or modify it under the terms of the GNU
  * General Public License as published by the Free
  * Software Foundation; either version 2 of the License,
  * or (at your option) any later version.
  *
  * This program is distributed in the hope that it will
  * be useful, but WITHOUT ANY WARRANTY; without even the
  * implied warranty of MERCHANTABILITY or FITNESS FOR A
  * PARTICULAR PURPOSE. See the GNU General Public License
  * for more details.

  Description:
  This class can generate CAPTCHAs, see README for more details!

 ******************************************************************/
 error_reporting(E_ALL);

 class captcha
 {
  var $Length;
  var $CaptchaString;
  var $fontpath;
  var $fonts;
  function captcha ($length = 6)
  {
   header('Content-type: image/png');
   $this->Length  = $length;
   //$this->fontpath = dirname($_SERVER['SCRIPT_FILENAME']) . '/fonts/';
   $this->fontpath = './fonts/';
   $this->fonts  = $this->getFonts();
   $errormgr    = new error;

   if ($this->fonts == false)
   { //$errormgr = new error;
     $errormgr->addError('No fonts available!');
     $errormgr->displayError();
     die();
   }
   if (function_exists('imagettftext') == false)
   {$errormgr->addError('');
    $errormgr->displayError();
    die();
   }
   $this->stringGen();
   $this->makeCaptcha();
  } //captcha

  function getFonts ()
  {
   $fonts = [];
   if ($handle = @opendir($this->fontpath))
   {
    while (($file = readdir($handle)) !== false)
    {$extension = strtolower(substr($file, strlen($file) - 3, 3));
     if ($extension == 'ttf')  $fonts[] = $file;
    }
    closedir($handle);
   }
   else return false;
   if (count($fonts) == 0) return false;
   else     return $fonts;

  } //getFonts

  function getRandFont ()
  {
   return $this->fontpath . $this->fonts[mt_rand(0, count($this->fonts) - 1)];
  } //getRandFont

  function stringGen ()
  {
   $uppercase = range('A', 'Z');
   //$lowercase = range('a', 'z');
   $numeric  = range(0, 9);
   $CharPool  = array_merge($uppercase, $numeric);
   $PoolLength = count($CharPool) - 1;
   for ($i = 0; $i < $this->Length; $i++)
       $this->CaptchaString .= $CharPool[mt_rand(0, $PoolLength)];
  } //StringGen

  function makeCaptcha ()
  {
   $imagelength = $this->Length * 25 + 16;
   $imageheight = 75;
   $image    = imagecreate($imagelength, $imageheight);
   //$bgcolor   = imagecolorallocate($image, 222, 222, 222);
   $bgcolor   = imagecolorallocate($image, 255, 255, 255);
   $stringcolor = imagecolorallocate($image, 0, 0, 0);
   $filter   = new filters;
   $filter->signs($image, $this->getRandFont());
   for ($i = 0; $i < strlen($this->CaptchaString); $i++)
   {imagettftext($image, 25, mt_rand(-15, 15), $i * 25 + 10,
           mt_rand(30, 70),
           $stringcolor,
           $this->getRandFont(),
           $this->CaptchaString{$i});
   }
   //$filter->noise($image, 10);
   //$filter->blur($image, 6);
   imagepng($image);
   imagedestroy($image);
  } //MakeCaptcha

  function getCaptchaString ()
  {
   return $this->CaptchaString;
  } //GetCaptchaString

 } //class: captcha


 class error
 {
   var $errors;
   function error ()
   {
    $this->errors = [];
   } //error

   function addError ($errormsg)
   {
    $this->errors[] = $errormsg;
   } //addError

   function displayError ()
   {
   $iheight   = count($this->errors) * 20 + 10;
   $iheight   = ($iheight < 130) ? 130 : $iheight;
   $image    = imagecreate(600, $iheight);
   $errorsign  = imagecreatefromjpeg('./gfx/errorsign.jpg');
   imagecopy($image, $errorsign, 1, 1, 1, 1, 180, 120);
   $bgcolor   = imagecolorallocate($image, 255, 255, 255);
   $stringcolor = imagecolorallocate($image, 0, 0, 0);
   for ($i = 0; $i < count($this->errors); $i++)
    {$imx = ($i == 0) ? $i * 20 + 5 : $i * 20;
     $msg = 'Error[' . $i . ']: ' . $this->errors[$i];
     imagestring($image, 5, 190, $imx, $msg, $stringcolor);
    }
   imagepng($image);
   imagedestroy($image);
   } //displayError

   function isError ()
   {
    if (count($this->errors) == 0)  return false;
    else                return true;
   } //isError
 } //class: error

 class filters
 {
  function noise (&$image, $runs = 30)
  {
   $w = imagesx($image);
   $h = imagesy($image);
   for ($n = 0; $n < $runs; $n++)
   {
    for ($i = 1; $i <= $h; $i++)
    {
     $randcolor = imagecolorallocate($image,
                     mt_rand(0, 255),
                     mt_rand(0, 255),
                     mt_rand(0, 255));
     imagesetpixel($image,
            mt_rand(1, $w),
            mt_rand(1, $h),
            $randcolor);
    }
   }
  } //noise

  function signs (&$image, $font, $cells = 3)
  {
   $w = imagesx($image);
   $h = imagesy($image);
     for ($i = 0; $i < $cells; $i++)
     {  $centerX   = mt_rand(1, $w);
    $centerY   = mt_rand(1, $h);
    $amount   = mt_rand(1, 15);
    $stringcolor = imagecolorallocate($image, 175, 175, 175);

       for ($n = 0; $n < $amount; $n++)
       {$signs = range('A', 'Z');
    $sign = $signs[mt_rand(0, count($signs) - 1)];
        imagettftext($image, 25,
              mt_rand(-15, 15),
              $centerX + mt_rand(-50, 50),
              $centerY + mt_rand(-50, 50),
              $stringcolor, $font, $sign);
       }
     }
  } //signs

  function blur (&$image, $radius = 3)
  {
   $radius = round(max(0, min($radius, 50)) * 2);
   $w    = imagesx($image);
   $h    = imagesy($image);
   $imgBlur = imagecreate($w, $h);
   for ($i = 0; $i < $radius; $i++)
   {
    imagecopy   ($imgBlur, $image,  0, 0, 1, 1, $w - 1, $h - 1);
    imagecopymerge($imgBlur, $image,  1, 1, 0, 0, $w,   $h,   50.0000);
    imagecopymerge($imgBlur, $image,  0, 1, 1, 0, $w - 1, $h,   33.3333);
    imagecopymerge($imgBlur, $image,  1, 0, 0, 1, $w,   $h - 1, 25.0000);
    imagecopymerge($imgBlur, $image,  0, 0, 1, 0, $w - 1, $h,   33.3333);
    imagecopymerge($imgBlur, $image,  1, 0, 0, 0, $w,   $h,   25.0000);
    imagecopymerge($imgBlur, $image,  0, 0, 0, 1, $w,   $h - 1, 20.0000);
    imagecopymerge($imgBlur, $image,  0, 1, 0, 0, $w,   $h,   16.6667);
    imagecopymerge($imgBlur, $image,  0, 0, 0, 0, $w,   $h,   50.0000);
    imagecopy   ($image , $imgBlur, 0, 0, 0, 0, $w,   $h);
   }
   imagedestroy($imgBlur);
  } //blur
 } //class: filters