92 lines
3.3 KiB
PHP
92 lines
3.3 KiB
PHP
<?php defined('SYSPATH') OR die('No direct access allowed.');
|
|
/**
|
|
* Captcha driver for "alpha" style.
|
|
*
|
|
* $Id: Alpha.php 4367 2009-05-27 21:23:57Z samsoir $
|
|
*
|
|
* @package Captcha
|
|
* @author Kohana Team
|
|
* @copyright (c) 2007-2008 Kohana Team
|
|
* @license http://kohanaphp.com/license.html
|
|
*/
|
|
class Captcha_Alpha_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(0, 100), mt_rand(0, 100), mt_rand(0, 100));
|
|
$color2 = imagecolorallocate($this->image, mt_rand(0, 100), mt_rand(0, 100), mt_rand(0, 100));
|
|
$this->image_gradient($color1, $color2);
|
|
}
|
|
|
|
// Add a few random circles
|
|
for ($i = 0, $count = mt_rand(10, Captcha::$config['complexity'] * 3); $i < $count; $i++)
|
|
{
|
|
$color = imagecolorallocatealpha($this->image, mt_rand(0, 255), mt_rand(0, 255), mt_rand(0, 255), mt_rand(80, 120));
|
|
$size = mt_rand(5, Captcha::$config['height'] / 3);
|
|
imagefilledellipse($this->image, mt_rand(0, Captcha::$config['width']), mt_rand(0, Captcha::$config['height']), $size, $size, $color);
|
|
}
|
|
|
|
// Calculate character font-size and spacing
|
|
$default_size = min(Captcha::$config['width'], Captcha::$config['height'] * 2) / strlen($this->response);
|
|
$spacing = (int) (Captcha::$config['width'] * 0.9 / strlen($this->response));
|
|
|
|
// Background alphabetic character attributes
|
|
$color_limit = mt_rand(96, 160);
|
|
$chars = 'ABEFGJKLPQRTVY';
|
|
|
|
// Draw each Captcha character with varying attributes
|
|
for ($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'])];
|
|
|
|
$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;
|
|
|
|
// Draw captcha text character
|
|
// Allocate random color, size and rotation attributes to text
|
|
$color = imagecolorallocate($this->image, mt_rand(150, 255), mt_rand(200, 255), mt_rand(0, 255));
|
|
|
|
// Write text character to image
|
|
imagefttext($this->image, $size, $angle, $x, $y, $color, $font, $this->response[$i]);
|
|
|
|
// Draw "ghost" alphabetic character
|
|
$text_color = imagecolorallocatealpha($this->image, mt_rand($color_limit + 8, 255), mt_rand($color_limit + 8, 255), mt_rand($color_limit + 8, 255), mt_rand(70, 120));
|
|
$char = $chars[mt_rand(0, 14)];
|
|
imagettftext($this->image, $size * 2, mt_rand(-45, 45), ($x - (mt_rand(5, 10))), ($y + (mt_rand(5, 10))), $text_color, $font, $char);
|
|
}
|
|
|
|
// Output
|
|
return $this->image_render($html);
|
|
}
|
|
|
|
} // End Captcha Alpha Driver Class
|