Implements an image recognition captcha.

"; break; case 'admin/modules#description': case 'admin/modules/textimage': case 'admin/textimage': $output = t('Implements an image recognition captcha.'); break; } return $output; } function textimage_captchachallenge(&$form) { $form['captcha_response'] = array ( '#type' => 'textfield', '#title' => t('Captcha Validation'), '#default_value' => '', '#required' => TRUE, '#validate' => array('_captcha_validate' => array()), '#description' => t('Please type in the letters/numbers that are shown in the image above.'), '#prefix' => 'Captcha Image: you will need to recognize the text in it.', ); return $form; } function textimage_captchavalidate(&$captcha_word, &$correct) { $captcha_word = drupal_strtolower($captcha_word); if (($_SESSION['captcha'] != '') && $captcha_word == $_SESSION['captcha']) { $correct = true; } else { $correct = false; form_set_error('captcha_response', t('The image verification code you entered is incorrect.')); } } /** * Implementation of hook_menu(). */ function textimage_menu($may_cache) { $items = array(); $suffix = ''; if (arg(2)!=null) $suffix='/'.arg(2); $items[] = array( 'path' => '_textimage/image'.$suffix, 'title' => t('textimage'), 'callback' => '_textimage_image', 'access' => user_access('access textimages'), 'type' => MENU_CALLBACK ); return $items; } function textimage_perm() { return array('access textimages'); } function textimage_settings() { $fonts_path = variable_get("textimage_fonts_path", ""); $images_path = variable_get("textimage_images_path", ""); //check for GD if (!function_exists(imagecreate)) drupal_set_message(t('Image library not available. Textimage needs the GD library extension to be installed. Please install GD.')); //check for TTF support elseif (!function_exists(imagettftext)) drupal_set_message(t('Your image library does not seem to have TrueType font support. Textimage will work, but will use the default inbuilt font.'),'status'); //check for valid font path elseif ($fonts_path!="" && !is_dir($fonts_path)) drupal_set_message(t('The current font path is invalid. The default font will be used.')); //check for valid image path if ($images_path!="" && !is_dir($images_path)) drupal_set_message(t('The current images path is invalid. No images will be used.')); //Fonts settings $form['fonts'] = array( '#type' => 'fieldset', '#title' => t('Fonts settings'), '#collapsible' => TRUE, '#collapsed' => FALSE ); $form['fonts']['textimage_use_only_upper'] = array( '#type' => 'checkbox', '#title' => t('Use only Uppercase'), '#default_value' => variable_get('textimage_use_only_upper',0) ); $form['fonts']['textimage_fonts_path'] = array( '#type' => 'textfield', '#title' => t('TrueType Fonts Path'), '#default_value' => $fonts_path, '#size' => 30, '#maxlength' => 255, '#description' => t('Location of the directory where the Truetype (.ttf) fonts are stored. If you do not provide any fonts, the module will use the default font for text. Relative paths will be resolved relative to the Drupal installation directory.'), ); $form['fonts']['textimage_font_size'] = array( '#type' => 'textfield', '#title' => t('Font Size'), '#default_value' => variable_get('textimage_font_size',24), '#size' => 5, '#maxlength' => 2, '#description' => t('Font size of Captcha text (in pixels).'), '#validate' => array("_textimage_number_validate" => array("textimage_font_size")), ); $form['fonts']['textimage_char_spacing_max'] = array( '#type' => 'textfield', '#title' => t('Character Spacing'), '#default_value' => variable_get('textimage_char_spacing_max',10), '#size' => 5, '#maxlength' => 4, '#description' => t('Sets the kerning between letters in Captcha. Higher numbers indicate more spacing.'), '#validate' => array("_textimage_number_validate" => array("textimage_char_spacing_max")), ); $form['fonts']['textimage_char_jiggle_amount'] = array( '#type' => 'textfield', '#title' => t('Character Jiggle'), '#default_value' => variable_get('textimage_char_jiggle_amount',5), '#size' => 5, '#maxlength' => 2, '#description' => t('Sets the amount of up and down movement in the Captcha letters. Higher numbers indicate more jiggling.'), '#validate' => array("_textimage_number_validate" => array("textimage_char_jiggle_amount")), ); $form['fonts']['textimage_char_rotate_amount'] = array( '#type' => 'textfield', '#title' => t('Character Rotation'), '#default_value' => variable_get('textimage_char_rotate_amount',5), '#size' => 5, '#maxlength' => 2, '#description' => t('Sets the amount of rotation in the Captcha letters (in degrees, only works with non-default fonts).'), '#validate' => array("_textimage_number_validate" => array("textimage_char_rotate_amount")), ); $form['fonts']['textimage_char_size_amount'] = array( '#type' => 'textfield', '#title' => t('Character Size Adjustment'), '#default_value' => variable_get('textimage_char_size_amount',2), '#size' => 5, '#maxlength' => 2, '#description' => t('Sets the amount of variation in size between the different letters in the Captcha (in pixels).'), '#validate' => array("_textimage_number_validate" => array("textimage_char_size_amount")), ); //Image settings $form['images'] = array( '#type' => 'fieldset', '#title' => t('Image settings'), '#collapsible' => TRUE, '#collapsed' => FALSE ); $form['images']['textimage_images_path'] = array( '#type' => 'textfield', '#title' => t('Background Images Path'), '#default_value' => $images_path, '#size' => 30, '#maxlength' => 255, '#description' => t('Location of the directory where the background images are stored. If you do not provide a directory, solid colors will be used. Relative paths will be resolved relative to the Drupal installation directory.'), ); $form['images']['textimage_image_noise'] = array( '#type' => 'textfield', '#title' => t('Image Noise (pixels)'), '#default_value' => variable_get('textimage_image_noise',4), '#size' => 5, '#maxlength' => 4, '#description' => t('Sets the amount of noise (random pixels) in the Captcha image. Higher numbers indicate more noise.'), '#validate' => array("_textimage_number_validate" => array("textimage_image_noise")), ); $form['images']['textimage_image_lines'] = array( '#type' => 'textfield', '#title' => t('Image Noise (lines)'), '#default_value' => variable_get('textimage_image_lines',4), '#size' => 5, '#maxlength' => 4, '#description' => t('Sets the amount of noise (random lines) in the Captcha image. Higher numbers indicate more noise.'), '#validate' => array("_textimage_number_validate" => array("textimage_image_lines")), ); $form['images']['textimage_image_margin'] = array( '#type' => 'textfield', '#title' => t('Image Margin'), '#default_value' => variable_get('textimage_image_margin',10), '#size' => 5, '#maxlength' => 4, '#description' => t('Set a distance between the Captcha letters and the edges of the image.'), '#validate' => array("_textimage_number_validate" => array("textimage_image_margin")), ); $form['info'] = array( '#type' => 'fieldset', '#title' => t('Image and font information'), '#collapsible' => TRUE, '#collapsed' => FALSE ); if (isset($fonts_path)) { $imagefontinfo .= t('Number of fonts found: ').count(_textimage_font_list()); } if (isset($images_path)) { $imagefontinfo .= '
'.t('Number of background images found: ').count(_textimage_image_list()); } $gdinfo = gd_info(); $imagefontinfo .= '
'.t('GD Version: ').$gdinfo["GD Version"]; $imagefontinfo .= '
'.t(' FreeType Support: '); $imagefontinfo .= ($gdinfo["FreeType Support"]==true) ? 'True' : 'False'; $imagefontinfo .= '
'; $form['info']['captcha_info'] = array ( '#type' => 'item', '#value' => $imagefontinfo, ); return $form; } function textimage_settings_form_validate ($form_id,$form) { //check for valid font path if ($form['textimage_fonts_path'] !="" && !is_dir($form['textimage_fonts_path'])) form_set_error('textimage_fonts_path', t('The entered font path is invalid')); //check for valid image path if ($form['textimage_images_path'] !="" && !is_dir($form['textimage_images_path'])) form_set_error('textimage_images_path', t('The entered image path is invalid')); } function _textimage_number_validate ($field,$fieldName) { if (!is_numeric($field['#value'])) { form_set_error($fieldName,t("The value for")." ".t($field['#title'])." ".t("must be a number")); } } /** * Prints an image containing a textimage code. */ function _textimage_image() { //if we don't have GD2 functions, we can't generate the image if (!function_exists('imagecreatetruecolor')) return; // Set headers header('Expires: Mon, 01 Jan 1997 05:00:00 GMT'); header('Cache-Control: no-store, no-cache, must-revalidate'); header('Cache-Control: post-check=0, pre-check=0', false); header('Pragma: no-cache'); header('Content-type: image/png'); $string = _textimage_code(); // Get truetype font list $fonts = _textimage_font_list(); // Get the background images list $images = _textimage_image_list(); // Randomization amounts: $charSpacingMax = variable_get('textimage_char_spacing_max',10); // Letter spacing max (pixels) $charSpacingMin = max($charSpacingMax*.5,0); // Letter spacing minimum (pixels) $charJiggleAmount = variable_get('textimage_char_jiggle_amount',5); // Up and down randomization (pixels) $charRotateAmount = variable_get('textimage_char_rotate_amount',5); // Character rotation amount (degrees) $charSizeAmount = variable_get('textimage_char_size_amount',2); // Character size amount (pixels) $imageRotateAmount = variable_get('captcha_image_rotate_amount',12); // Image rotation amount (degrees) // Static amounts: $charInitialSize = variable_get('textimage_font_size',24); // Initial Font $imageNoise = variable_get('textimage_image_noise',4); // Amount of noise added to image $imageLines = variable_get('textimage_image_lines',4); // Amount of noise added to image $imageMargin = variable_get('textimage_image_margin',10); // Margin around image (pixels) // write text using a truetype font if (function_exists(imagettftext) && count($fonts) > 0) { // Initialize variables for the loop $characterDetails = array(); // contains the final info about each character // Build a list of character settings for the captcha string for ($i=0;$i $charSize, "angle" => $charAngle, "x" => $x, "y" => $y, "color" => $foreground, "font" => $font, "char" => $char ); // Increment the image size $imageWidth = $x + $charWidth; $imageHeight = max($imageHeight,$y+$charJiggleAmount); } // Create the image based off the string length and margin if (count($images) > 0) { // We're going to be using an image, and need a tranparent background to start with $im = _textimage_create_transparent_image($imageWidth+2*$imageMargin, $imageHeight+2*$imageMargin); $noisecolor = imagecolorallocatealpha($im, 0, 0, 0, 127); } else { // Just make a plain-jane color brackground $im = imagecreatetruecolor($imageWidth+2*$imageMargin, $imageHeight+2*$imageMargin); $background = imagecolorallocate($im, rand(180, 250), rand(180, 250), rand(180, 250)); $noisecolor = $background; imagefill($im, 0, 0, $background); } // Specify colors to be used in the image $foreground = imagecolorallocate($im, rand(0, 80), rand(0, 80), rand(0, 80)); foreach($characterDetails as $char) { // draw character imagettftext($im,$char['size'],$char['angle'],$char['x']+$imageMargin,$char['y']+$imageMargin,$foreground,$char['font'],$char['char']); } } else { // write text using a built-in font $x = 0; $y = 0; $imageWidth = 60 + drupal_strlen($string)*$charSpacingMax*.35; $imageHeight = 30 + $charJiggleAmount; // Create the image if (count($images) > 0 && function_exists(imagecolorallocatealpha)) { // We're going to be using an image, and need a tranparent background to start with $im = _textimage_create_transparent_image($imageWidth, $imageHeight); $noisecolor = imagecolorallocatealpha($im, 0, 0, 0, 127); } else { // Just make a plain-jane color brackground $im = imagecreatetruecolor($imageWidth, $imageHeight); $background = imagecolorallocate($im, rand(180, 250), rand(180, 250), rand(180, 250)); $noisecolor = $background; imagefill($im, 0, 0, $background); } // Add the text for ($i=0;$i 0) { // Prepare a larger image with a background image $im2 = _textimage_create_transparent_image($imageWidth, $imageHeight); } else { // Prepare a larger image with a solid color $im2 = imagecreatetruecolor($imageWidth, $imageHeight); imagefill($im2, 0, 0, $background); } $result = imagecopyresampled ($im2, $im, $imageMargin, $imageMargin, 0, 0, $imageWidth, $imageHeight, imagesx($im), imagesy($im)); $im = $im2; } // strikethrough imageline($im, rand(0, 120), rand(0, 120), rand(0, 120), rand(0, 120), $foreground); // Add Noise for ($x=0; $x<$imageWidth; $x++) { for ($row=0; $row<$imageNoise;$row++) { $y = rand(0,$imageHeight); imagesetpixel($im, $x, $y, $noisecolor); } } // Add Lines and Ellipses for ($x=0; $x<$imageLines;$x++) { imageline($im, rand(0, $imageWidth), rand(0, $imageHeight), rand(0, $imageWidth), rand(0, $imageHeight), $noisecolor); imageellipse($im, rand(0, $imageWidth), rand(0, $imageHeight), rand(0, $imageWidth), rand(0, $imageHeight), $noisecolor); } // Fill image with a random background image if available if (count($images) > 0) { $image = $images[rand(0,count($images)-1)]; _textimage_apply_background_image($im,$image); } //output to browser imagepng($im); imagedestroy($im); } /** * Returns a random string for use in a captcha */ function _textimage_code() { $consts='bcdgjxvmnprst'; $vowels='aeiou'; for ($x=0; $x < 6; $x++) { mt_srand ((double) microtime() * 1000000); $const[$x] = drupal_substr($consts,mt_rand(0,drupal_strlen($consts)-1),1); $vow[$x] = drupal_substr($vowels,mt_rand(0,drupal_strlen($vowels)-1),1); } $string = $const[0] . $vow[0] .$const[2] . $const[1] . $vow[1] . $const[3] . $vow[3] . $const[4]; $string = drupal_substr($string,0,rand(4,6)); //everytime we create a new code, we write it to session $_SESSION['captcha'] = drupal_strtolower($string); if(variable_get('textimage_use_only_upper',0)) $string = drupal_strtoupper($string); return $string; } /** * Returns an array of files with TTF extensions in the specified directory. */ function _textimage_font_list() { $fontdir = variable_get("textimage_fonts_path", ""); $filelist = array(); if (is_dir($fontdir) && $handle = opendir($fontdir)) { while ($file = readdir($handle)) { if (preg_match("/\.ttf$/i",$file) == 1) $filelist[] = $fontdir.'/'.$file; } closedir($handle); } return $filelist; } /** * Returns an array of files with jpg, png, and gif extensions in the specified directory. */ function _textimage_image_list() { $imagesdir = variable_get("textimage_images_path", ""); $filelist = array(); if (is_dir($imagesdir) && $handle = opendir($imagesdir)) { while ($file = readdir($handle)) { if (preg_match("/\.gif|\.png|\.jpg$/i",$file) == 1) $filelist[] = $imagesdir.'/'.$file; } closedir($handle); } return $filelist; } /** * Overlays an image to the supplied image resource */ function _textimage_apply_background_image (&$imageResource,$imageFile) { $backgroundResource = image_gd_open($imageFile,substr($imageFile,-3)); // Copy the text onto the background $backX = imagesx($backgroundResource); $backY = imagesy($backgroundResource); $textX = imagesx($imageResource); $textY = imagesy($imageResource); $randomBackX = rand(0,$backX-$textX); $randomBackY = rand(0,$backY-$textY); // Place the text onto a random location of the background image imagecopyresampled($backgroundResource,$imageResource,$randomBackX,$randomBackY,0,0,$textX,$textY,$textX,$textY); // Crop the background image to the original image size imagecopyresampled($imageResource,$backgroundResource,0,0,$randomBackX,$randomBackY,$textX,$textY,$textX,$textY); } /** * Creates transparent image resources for images with graphic backgrounds */ function _textimage_create_transparent_image($x, $y) { $i = imagecreatetruecolor($x, $y); $b = imagecreatefromstring(base64_decode(_text_image_blankpng())); imagealphablending($i, false); imagesavealpha($i, true); imagecopyresized($i, $b ,0 ,0 ,0 ,0 ,$x, $y, imagesx($b), imagesy($b)); return $i; } function _text_image_blankpng() { $c = "iVBORw0KGgoAAAANSUhEUgAAACgAAAAoCAYAAACM/rhtAAAABGdBTUEAAK/INwWK6QAAABl0RVh0U29m"; $c .= "dHdhcmUAQWRvYmUgSW1hZ2VSZWFkeXHJZTwAAADqSURBVHjaYvz//z/DYAYAAcTEMMgBQAANegcCBNCg"; $c .= "dyBAAA16BwIE0KB3IEAADXoHAgTQoHcgQAANegcCBNCgdyBAAA16BwIE0KB3IEAADXoHAgTQoHcgQAAN"; $c .= "egcCBNCgdyBAAA16BwIE0KB3IEAADXoHAgTQoHcgQAANegcCBNCgdyBAAA16BwIE0KB3IEAADXoHAgTQ"; $c .= "oHcgQAANegcCBNCgdyBAAA16BwIE0KB3IEAADXoHAgTQoHcgQAANegcCBNCgdyBAAA16BwIE0KB3IEAA"; $c .= "DXoHAgTQoHcgQAANegcCBNCgdyBAgAEAMpcDTTQWJVEAAAAASUVORK5CYII="; return $c; } ?> oellermann.com

  • warning: Creating default object from empty value in /var/www/oellermann/modules/spam/spam.module on line 488.
  • : preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in /var/www/oellermann/includes/unicode.inc on line 291.

MySQL and Visual Studio.NET

| |

This weekend I started working on FICSiface, a sort of toolkit to getting software hooked up to the Free Internet Chess Server (FICS). My initial plan was to have a class that could connect to FICS, send data, and raise events when FICS sends data to it. This came together quite quickly (remind me to talk about asynchronous IO soon), and of course I got carried away. I decided it would be nice to use it to hook up Blikskottel , my chess engine, which would run as a Windows service. All of this glue stuff is being written in C#, because one day it would be nice to run it on Mono. Then I got carried away some more. While I was testing on FICS (my computer account, Skottel, having been reactivated by an extremely helpful and industrious FICS admin - thanks!), Blik (another computer, Rookie by Marcel Kervinck) came on and made some random joke. So I thought, in light of the fact that Blikskottel is now based in Scotland, it would be cool if Skottel could make self-deprecating jokes about Scotsmen from time to time. In order not to be boring, it would need a biggish database of jokes - and Google came through handsomely.

Now where to put them?

Being a fan of MySQL (chiefly on Linux), I decided it would be neat to try it on Windows for this application. The MySQL 5 Installer downloaded and ran without a hitch, as did the GUI tools (and very nicely done, too - well done MySQL). Then I installed MySQL Connector/NET, a provider for MySQL which acts just like System.Data.SqlClient. Believe it or not, it all just worked - consider the following code snippet:

using (MySqlConnection conn = new MySqlConnection("server=localhost; database=fics; uid=foo; pwd=bar"))
{
conn.Open();

// get a joke we haven't used for a while
MySqlCommand cmd = null;
try
{
cmd = conn.CreateCommand();
cmd.CommandText = "select ID, Joke from jokes order by LastUsed LIMIT 1";
cmd.CommandType = CommandType.Text;
MySqlDataReader rdr = cmd.ExecuteReader();
rdr.Read();
jokeID = rdr.GetInt32(0);
joke = rdr.GetString(1);
rdr.Close();
}
finally
{
cmd.Dispose();
}
}

 

Simple as that. Of course, MySQL 5 can actually do stored procs as well, so we'll have to investigate that next, but to cut a long story short, it was surprisingly easy and familiar to use MySQL from a .NET application.

Why Would Anyone Bother?

I know what you're going to say - why would you not use SQL Server? Or SQL Server Express, that's free? Of course, "free" is important to me - I don't own a SQL Server license, and I won't countenance using software illegally. However, SQL Server Express has limitations - just the one CPU, just the 1GB of RAM, just the 4GB of database size, just the one operating system. What happens if I collect more than 4GB of Scotsman jokes ("Did ye hear the one aboot the sasannach whae tol' 4GB of Scots jokes?" "Och, nae, laddie." "Seems a caber fell on him and he had nae backup!")? More importantly, what if I want to run it on Linux/BSD/whatever? MySQL solves all these problems, and is quite a nice database to my way of thinking. But most importantly, it's Free. I have the source code, and if MySQL engages in any unpleasant business practices aimed at reducing the utility of the customer, there would be a fully-supported fork in seconds. If I have issues with the database which the vendor isn't interested, I can fix them - although I have no issues, and come to think of it, not a lot of time to be grovelling around in the code of one of the world's eminent databases - but it's the thought that counts!


Reply

  • Allowed HTML tags: <a> <em> <strong> <cite> <code> <ul> <ol> <li> <dl> <dt> <dd> <p> <br> <h1> <h2> <h3>
  • Lines and paragraphs break automatically.
  • You may use [acidfree:xx] tags to display acidfree videos or images inline.
  • Images can be added to this post.
More information about formatting options