/modules/captcha/classes/captcha/black.php
PHP | 74 lines | 36 code | 9 blank | 29 comment | 1 complexity | be76504fb2753c2fcbaaca037e01eafd MD5 | raw file
Possible License(s): BSD-3-Clause, LGPL-2.1
- <?php defined('SYSPATH') OR die('No direct access.');
- /**
- * Black captcha class.
- *
- * @package Captcha
- * @subpackage Captcha_Black
- * @author Michael Lavers
- * @author Kohana Team
- * @copyright (c) 2008-2010 Kohana Team
- * @license http://kohanaphp.com/license.html
- */
- class Captcha_Black extends Captcha
- {
- /**
- * Generates a new Captcha challenge.
- *
- * @return string The challenge answer
- */
- public function generate_challenge()
- {
- // Complexity setting is used as character count
- $text = text::random('distinct', max(1, ceil(Captcha::$config['complexity'] / 1.5)));
-
- return $text;
- }
- /**
- * Outputs the Captcha image.
- *
- * @param boolean $html HTML output
- * @return mixed
- */
- public function render($html = TRUE)
- {
- // Creates a black image to start from
- $this->image_create(Captcha::$config['background']);
- // Add random white/gray arcs, amount depends on complexity setting
- $count = (Captcha::$config['width'] + Captcha::$config['height']) / 2;
- $count = $count / 5 * min(10, Captcha::$config['complexity']);
- for ($i = 0; $i < $count; $i++)
- {
- imagesetthickness($this->image, mt_rand(1, 2));
- $color = imagecolorallocatealpha($this->image, 255, 255, 255, mt_rand(0, 120));
- imagearc($this->image, mt_rand(-Captcha::$config['width'], Captcha::$config['width']), mt_rand(-Captcha::$config['height'], Captcha::$config['height']), mt_rand(-Captcha::$config['width'], Captcha::$config['width']), mt_rand(-Captcha::$config['height'], Captcha::$config['height']), mt_rand(0, 360), mt_rand(0, 360), $color);
- }
- // Use different fonts if available
- $font = Captcha::$config['fontpath'].Captcha::$config['fonts'][array_rand(Captcha::$config['fonts'])];
- // Draw the character's white shadows
- $size = (int) min(Captcha::$config['height'] / 2, Captcha::$config['width'] * 0.8 / strlen($this->response));
- $angle = mt_rand(-15 + strlen($this->response), 15 - strlen($this->response));
- $x = mt_rand(1, Captcha::$config['width'] * 0.9 - $size * strlen($this->response));
- $y = ((Captcha::$config['height'] - $size) / 2) + $size;
- $color = imagecolorallocate($this->image, 255, 255, 255);
- imagefttext($this->image, $size, $angle, $x + 1, $y + 1, $color, $font, $this->response);
- // Add more shadows for lower complexities
- (Captcha::$config['complexity'] < 10) and imagefttext($this->image, $size, $angle, $x - 1, $y - 1, $color, $font , $this->response);
- (Captcha::$config['complexity'] < 8) and imagefttext($this->image, $size, $angle, $x - 2, $y + 2, $color, $font , $this->response);
- (Captcha::$config['complexity'] < 6) and imagefttext($this->image, $size, $angle, $x + 2, $y - 2, $color, $font , $this->response);
- (Captcha::$config['complexity'] < 4) and imagefttext($this->image, $size, $angle, $x + 3, $y + 3, $color, $font , $this->response);
- (Captcha::$config['complexity'] < 2) and imagefttext($this->image, $size, $angle, $x - 3, $y - 3, $color, $font , $this->response);
- // Finally draw the foreground characters
- $color = imagecolorallocate($this->image, 0, 0, 0);
- imagefttext($this->image, $size, $angle, $x, $y, $color, $font, $this->response);
- // Output
- return $this->image_render($html);
- }
- } // End Captcha Black Driver Class