/system/libraries/drivers/Captcha/Basic.php
PHP | 81 lines | 36 code | 12 blank | 33 comment | 3 complexity | fa22c3e8e30c2ab1a4a7cc6e2363cd01 MD5 | raw file
- <?php defined('SYSPATH') or die('No direct script access.');
- /**
- * Captcha driver for "basic" style.
- *
- * $Id: Basic.php 3104 2008-07-13 12:06:52Z Geert $
- *
- * @package Captcha
- * @author Kohana Team
- * @copyright (c) 2007-2008 Kohana Team
- * @license http://kohanaphp.com/license.html
- */
- class Captcha_Basic_Driver extends Captcha_Driver {
- /**
- * Generates a new Captcha challenge.
- *
- * @return string the challenge answer
- */
- public function generate_challenge()
- {
- // Complexity setting is used as character count
- return text::random('distinct', max(1, Captcha::$config['complexity']));
- }
- /**
- * Outputs the Captcha image.
- *
- * @param boolean html output
- * @return mixed
- */
- public function render($html)
- {
- // Creates $this->image
- $this->image_create(Captcha::$config['background']);
- // Add a random gradient
- if (empty(Captcha::$config['background']))
- {
- $color1 = imagecolorallocate($this->image, mt_rand(200, 255), mt_rand(200, 255), mt_rand(150, 255));
- $color2 = imagecolorallocate($this->image, mt_rand(200, 255), mt_rand(200, 255), mt_rand(150, 255));
- $this->image_gradient($color1, $color2);
- }
- // Add a few random lines
- for ($i = 0, $count = mt_rand(5, Captcha::$config['complexity'] * 4); $i < $count; $i++)
- {
- $color = imagecolorallocatealpha($this->image, mt_rand(0, 255), mt_rand(0, 255), mt_rand(100, 255), mt_rand(50, 120));
- imageline($this->image, mt_rand(0, Captcha::$config['width']), 0, mt_rand(0, Captcha::$config['width']), Captcha::$config['height'], $color);
- }
- // Calculate character font-size and spacing
- $default_size = min(Captcha::$config['width'], Captcha::$config['height'] * 2) / (strlen($this->response) + 1);
- $spacing = (int) (Captcha::$config['width'] * 0.9 / strlen($this->response));
- // Draw each Captcha character with varying attributes
- for ($i = 0, $strlen = strlen($this->response); $i < $strlen; $i++)
- {
- // Use different fonts if available
- $font = Captcha::$config['fontpath'].Captcha::$config['fonts'][array_rand(Captcha::$config['fonts'])];
- // Allocate random color, size and rotation attributes to text
- $color = imagecolorallocate($this->image, mt_rand(0, 150), mt_rand(0, 150), mt_rand(0, 150));
- $angle = mt_rand(-40, 20);
- // Scale the character size on image height
- $size = $default_size / 10 * mt_rand(8, 12);
- $box = imageftbbox($size, $angle, $font, $this->response[$i]);
- // Calculate character starting coordinates
- $x = $spacing / 4 + $i * $spacing;
- $y = Captcha::$config['height'] / 2 + ($box[2] - $box[5]) / 4;
- // Write text character to image
- imagefttext($this->image, $size, $angle, $x, $y, $color, $font, $this->response[$i]);
- }
- // Output
- return $this->image_render($html);
- }
- } // End Captcha Basic Driver Class