1 files changed, 92 insertions, 0 deletions
diff --git a/system/libraries/drivers/Captcha/Alpha.php b/system/libraries/drivers/Captcha/Alpha.php
new file mode 100644
index 00000000..b3a9c9d7
--- /dev/null
+++ b/system/libraries/drivers/Captcha/Alpha.php
@@ -0,0 +1,92 @@
+<?php defined('SYSPATH') OR die('No direct access allowed.');
+/**
+ * Captcha driver for "alpha" style.
+ *
+ * $Id: Alpha.php 3769 2008-12-15 00:48:56Z zombor $
+ *
+ * @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));
+			$char = substr($chars, mt_rand(0, 14), 1);
+			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
+\ No newline at end of file