<?php defined('SYSPATH') OR die('No direct access.');
/**
* Math captcha class.
*
* @package Captcha
* @subpackage Captcha_Math
* @author Michael Lavers
* @author Kohana Team
* @copyright (c) 2008-2010 Kohana Team
* @license http://kohanaphp.com/license.html
*/
class Captcha_Math extends Captcha
{
/**
* @var string Captcha math exercise
*/
private $math_exercise;
/**
* Generates a new Captcha challenge.
*
* @return string The challenge answer
*/
public function generate_challenge()
{
// Easy
if (Captcha::$config['complexity'] < 4)
{
$numbers[] = mt_rand(1, 5);
$numbers[] = mt_rand(1, 4);
}
// Normal
elseif (Captcha::$config['complexity'] < 7)
{
$numbers[] = mt_rand(10, 20);
$numbers[] = mt_rand(1, 10);
}
// Difficult, well, not really ;)
else
{
$numbers[] = mt_rand(100, 200);
$numbers[] = mt_rand(10, 20);
$numbers[] = mt_rand(1, 10);
}
// Store the question for output
$this->math_exercise = implode(' + ', $numbers).' = ';
// Return the answer
return array_sum($numbers);
}
/**
* Outputs the Captcha riddle.
*
* @param boolean $html HTML output
* @return mixed
*/
public function render($html = TRUE)
{
return $this->math_exercise;
}
} // End Captcha Math Driver Class