source: sourcecode/system/helpers/captcha_helper.php @ 1

<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.1.6 or newer
 *
 * @package             CodeIgniter
 * @author              ExpressionEngine Dev Team
 * @copyright   Copyright (c) 2008 - 2011, EllisLab, Inc.
 * @license             http://codeigniter.com/user_guide/license.html
 * @link                http://codeigniter.com
 * @since               Version 1.0
 * @filesource
 */

// ------------------------------------------------------------------------

/**
 * CodeIgniter CAPTCHA Helper
 *
 * @package             CodeIgniter
 * @subpackage  Helpers
 * @category    Helpers
 * @author              ExpressionEngine Dev Team
 * @link                http://codeigniter.com/user_guide/helpers/xml_helper.html
 */

// ------------------------------------------------------------------------

/**
 * Create CAPTCHA
 *
 * @access      public
 * @param       array   array of data for the CAPTCHA
 * @param       string  path to create the image in
 * @param       string  URL to the CAPTCHA image folder
 * @param       string  server path to font
 * @return      string
 */
if ( ! function_exists('create_captcha'))
{
        function create_captcha($data = '', $img_path = '', $img_url = '', $font_path = '')
        {
                $defaults = array('word' => '', 'img_path' => '', 'img_url' => '', 'img_width' => '150', 'img_height' => '30', 'font_path' => '', 'expiration' => 7200);

                foreach ($defaults as $key => $val)
                {
                        if ( ! is_array($data))
                        {
                                if ( ! isset($$key) OR $$key == '')
                                {
                                        $$key = $val;
                                }
                        }
                        else
                        {
                                $$key = ( ! isset($data[$key])) ? $val : $data[$key];
                        }
                }

                if ($img_path == '' OR $img_url == '')
                {
                        return FALSE;
                }

                if ( ! @is_dir($img_path))
                {
                        return FALSE;
                }

                if ( ! is_writable($img_path))
                {
                        return FALSE;
                }

                if ( ! extension_loaded('gd'))
                {
                        return FALSE;
                }

                // -----------------------------------
                // Remove old images
                // -----------------------------------

                list($usec, $sec) = explode(" ", microtime());
                $now = ((float)$usec + (float)$sec);

                $current_dir = @opendir($img_path);

                while ($filename = @readdir($current_dir))
                {
                        if ($filename != "." and $filename != ".." and $filename != "index.html")
                        {
                                $name = str_replace(".jpg", "", $filename);

                                if (($name + $expiration) < $now)
                                {
                                        @unlink($img_path.$filename);
                                }
                        }
                }

                @closedir($current_dir);

                // -----------------------------------
                // Do we have a "word" yet?
                // -----------------------------------

           if ($word == '')
           {
                        $pool = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';

                        $str = '';
                        for ($i = 0; $i < 8; $i++)
                        {
                                $str .= substr($pool, mt_rand(0, strlen($pool) -1), 1);
                        }

                        $word = $str;
           }

                // -----------------------------------
                // Determine angle and position
                // -----------------------------------

                $length = strlen($word);
                $angle  = ($length >= 6) ? rand(-($length-6), ($length-6)) : 0;
                $x_axis = rand(6, (360/$length)-16);
                $y_axis = ($angle >= 0 ) ? rand($img_height, $img_width) : rand(6, $img_height);

                // -----------------------------------
                // Create image
                // -----------------------------------

                // PHP.net recommends imagecreatetruecolor(), but it isn't always available
                if (function_exists('imagecreatetruecolor'))
                {
                        $im = imagecreatetruecolor($img_width, $img_height);
                }
                else
                {
                        $im = imagecreate($img_width, $img_height);
                }

                // -----------------------------------
                //  Assign colors
                // -----------------------------------

                $bg_color               = imagecolorallocate ($im, 255, 255, 255);
                $border_color   = imagecolorallocate ($im, 153, 102, 102);
                $text_color             = imagecolorallocate ($im, 204, 153, 153);
                $grid_color             = imagecolorallocate($im, 255, 182, 182);
                $shadow_color   = imagecolorallocate($im, 255, 240, 240);

                // -----------------------------------
                //  Create the rectangle
                // -----------------------------------

                ImageFilledRectangle($im, 0, 0, $img_width, $img_height, $bg_color);

                // -----------------------------------
                //  Create the spiral pattern
                // -----------------------------------

                $theta          = 1;
                $thetac         = 7;
                $radius         = 16;
                $circles        = 20;
                $points         = 32;

                for ($i = 0; $i < ($circles * $points) - 1; $i++)
                {
                        $theta = $theta + $thetac;
                        $rad = $radius * ($i / $points );
                        $x = ($rad * cos($theta)) + $x_axis;
                        $y = ($rad * sin($theta)) + $y_axis;
                        $theta = $theta + $thetac;
                        $rad1 = $radius * (($i + 1) / $points);
                        $x1 = ($rad1 * cos($theta)) + $x_axis;
                        $y1 = ($rad1 * sin($theta )) + $y_axis;
                        imageline($im, $x, $y, $x1, $y1, $grid_color);
                        $theta = $theta - $thetac;
                }

                // -----------------------------------
                //  Write the text
                // -----------------------------------

                $use_font = ($font_path != '' AND file_exists($font_path) AND function_exists('imagettftext')) ? TRUE : FALSE;

                if ($use_font == FALSE)
                {
                        $font_size = 5;
                        $x = rand(0, $img_width/($length/3));
                        $y = 0;
                }
                else
                {
                        $font_size      = 16;
                        $x = rand(0, $img_width/($length/1.5));
                        $y = $font_size+2;
                }

                for ($i = 0; $i < strlen($word); $i++)
                {
                        if ($use_font == FALSE)
                        {
                                $y = rand(0 , $img_height/2);
                                imagestring($im, $font_size, $x, $y, substr($word, $i, 1), $text_color);
                                $x += ($font_size*2);
                        }
                        else
                        {
                                $y = rand($img_height/2, $img_height-3);
                                imagettftext($im, $font_size, $angle, $x, $y, $text_color, $font_path, substr($word, $i, 1));
                                $x += $font_size;
                        }
                }


                // -----------------------------------
                //  Create the border
                // -----------------------------------

                imagerectangle($im, 0, 0, $img_width-1, $img_height-1, $border_color);

                // -----------------------------------
                //  Generate the image
                // -----------------------------------

                $img_name = $now.'.jpg';

                ImageJPEG($im, $img_path.$img_name);

                $img = "<img src=\"$img_url$img_name\" width=\"$img_width\" height=\"$img_height\" style=\"border:0;\" alt=\" \" />";

                ImageDestroy($im);

                return array('word' => $word, 'time' => $now, 'image' => $img);
        }
}

// ------------------------------------------------------------------------

/* End of file captcha_helper.php */
/* Location: ./system/heleprs/captcha_helper.php */