--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/imageserve.inc	Fri Feb 20 14:04:09 2009 +0000
@@ -0,0 +1,61 @@
+<?php
+// $Id: imageserve.inc,v 1.1.2.8.2.2 2009/02/16 17:06:47 jeremy Exp $
+
+/**
+ * @file
+ * Image serving lib.
+ *
+ * Copyright (c) 2008-2009.
+ *   Jeremy Andrews <jeremy@tag1consulting.com>.
+ */
+
+/**
+ * Generate a tiny image with GD, used to count when an ad has been displayed
+ * on a cached page.
+ */
+function adserve_counter_image() {
+  adserve_variable('variable_load');
+  adserve_bootstrap(0);
+
+  $ad->aid = adserve_variable('aid');
+  if ($ad->aid) {
+    adserve_increment($ad);
+  }
+  else {
+    adserve_increment($ad, 'count');
+  }
+
+  if (function_exists('imagecreate')) {
+    $image = imagecreate(1, 1);
+    // Tell the web browser not to cache this image so we register a count each
+    // time the page is viewed.
+    // Expires in the past:
+    header('Expires: Mon, 26 Jul 1997 05:00:00 GMT');
+    // Last loud:
+    header('Last-Modified: '. gmdate('D, d M Y H:i:s') .' GMT');
+    // HTTP 1.1:
+    header('Cache-Control: no-store, no-cache, must-revalidate');
+    header('Cache-Control: post-check=0, pre-check=0', FALSE);
+    // HTTP 1.0:
+    header('Pragma: no-cache');
+  }
+  else {
+    // GD not installed, report error and exit.
+    exit();
+  }
+
+  if (function_exists('imagejpeg')) {
+    header("Content-type: image/jpeg");
+    imagejpeg($image);
+  }
+  else if (function_exists('imagepng')) {
+    header("Content-type: image/png");
+    imagepng($image);
+  }
+  else if (function_exists('imagegif')) {
+    header("Content-type: image/gif");
+    imagegif($image);
+  }
+  imagedestroy($image);
+  exit(0);
+}