--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/imagetools.php	Tue Aug 05 13:17:57 2008 -0400
@@ -0,0 +1,205 @@
+<?php
+
+/**
+ * Greyhound - real web management for Amarok
+ * Copyright (C) 2008 Dan Fuhry
+ *
+ * This program is Free Software; you can redistribute and/or modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for details.
+ */
+
+/**
+ * Determines an image's filetype based on its signature.
+ * @param string Path to image file
+ * @return string One of gif, png, or jpg, or false if none of these.
+ */
+
+function get_image_filetype($filename)
+{
+  $filecontents = @file_get_contents($filename);
+  if ( empty($filecontents) )
+    return false;
+  
+  if ( substr($filecontents, 0, 8) == "\x89\x50\x4e\x47\x0d\x0a\x1a\x0a" )
+    return 'png';
+  
+  if ( substr($filecontents, 0, 6) == 'GIF87a' || substr($filecontents, 0, 6) == 'GIF89a' )
+    return 'gif';
+  
+  if ( substr($filecontents, 0, 2) == "\xFF\xD8" )
+    return 'jpg';
+  
+  return false;
+}
+
+/**
+ * Scales an image to the specified width and height, and writes the output to the specified
+ * file. Will use ImageMagick if present, but if not will attempt to scale with GD. This will
+ * always scale images proportionally.
+ * 
+ * Ported from Enano CMS (which is also my project)
+ * 
+ * @param string Path to image file
+ * @param string Path to output file
+ * @param int Image width, in pixels
+ * @param int Image height, in pixels
+ * @param bool If true, the output file will be deleted if it exists before it is written
+ * @return bool True on success, false on failure
+ */
+
+function scale_image($in_file, $out_file, $width = 225, $height = 225, $unlink = false)
+{
+  global $db, $session, $paths, $template, $plugins; // Common objects
+  
+  if ( !is_int($width) || !is_int($height) )
+    return false;
+  
+  if ( !file_exists($in_file) )
+    return false;
+  
+  if ( preg_match('/["\'\/\\]/', $in_file) || preg_match('/["\'\/\\]/', $out_file) )
+    return false;
+  
+  if ( file_exists($out_file) && !$unlink )
+    return false;
+  else if ( file_exists($out_file) && $unlink )
+    @unlink($out_file);
+  if ( file_exists($out_file) )
+    // couldn't unlink (delete) the output file
+    return false;
+    
+  $file_ext = substr($in_file, ( strrpos($in_file, '.') + 1));
+  switch($file_ext)
+  {
+    case 'png':
+      $func = 'imagecreatefrompng';
+      break;
+    case 'jpg':
+    case 'jpeg':
+      $func = 'imagecreatefromjpeg';
+      break;
+    case 'gif':
+      $func = 'imagecreatefromgif';
+      break;
+    case 'xpm':
+      $func = 'imagecreatefromxpm';
+      break;
+    default:
+      return false;
+  }
+    
+  // try to find convert in the PATH
+  // FIXME: unix specific (won't work on windows)
+  $path = ( isset($_ENV['PATH']) ) ? $_ENV['PATH'] : ( isset($_SERVER['PATH']) ? $_SERVER['PATH'] : '/usr/local/bin:/usr/bin:/bin' );
+  $path = explode(':', $path);
+  foreach ( $path as $dir )
+  {
+    if ( file_exists("$dir/convert") && is_executable("$dir/convert") )
+    {
+      $magick_path = "$dir/convert";
+    }
+  }
+  
+  $can_use_magick = isset($magick_path);
+  $can_use_gd = (
+      function_exists('getimagesize')         &&
+      function_exists('imagecreatetruecolor') &&
+      function_exists('imagecopyresampled')   &&
+      function_exists($func)
+    );
+  if ( $can_use_magick )
+  {
+    if ( !preg_match('/^([\/A-z0-9_-]+)$/', $magick_path) )
+    {
+      // ImageMagick path seems screwy
+      return false;
+    }
+    $cmdline = "\"$magick_path\" \"$in_file\" -resize \"{$width}x{$height}>\" \"$out_file\"";
+    system($cmdline, $return);
+    if ( !file_exists($out_file) )
+      return false;
+    return true;
+  }
+  else if ( $can_use_gd )
+  {
+    @list($width_orig, $height_orig) = @getimagesize($in_file);
+    if ( !$width_orig || !$height_orig )
+      return false;
+    // calculate new width and height
+    
+    $ratio = $width_orig / $height_orig;
+    if ( $ratio > 1 )
+    {
+      // orig. width is greater that height
+      $new_width = $width;
+      $new_height = round( $width / $ratio );
+    }
+    else if ( $ratio < 1 )
+    {
+      // orig. height is greater than width
+      $new_width = round( $height / $ratio );
+      $new_height = $height;
+    }
+    else if ( $ratio == 1 )
+    {
+      $new_width = $width;
+      $new_height = $width;
+    }
+    if ( $new_width > $width_orig || $new_height > $height_orig )
+    {
+      // Too big for our britches here; set it to only convert the file
+      $new_width = $width_orig;
+      $new_height = $height_orig;
+    }
+    
+    $newimage = @imagecreatetruecolor($new_width, $new_height);
+    if ( !$newimage )
+      return false;
+    $oldimage = @$func($in_file);
+    if ( !$oldimage )
+      return false;
+    
+    // Perform scaling
+    imagecopyresampled($newimage, $oldimage, 0, 0, 0, 0, $new_width, $new_height, $width_orig, $height_orig);
+    
+    // Get output format
+    $out_ext = substr($out_file, ( strrpos($out_file, '.') + 1));
+    switch($out_ext)
+    {
+      case 'png':
+        $outfunc = 'imagepng';
+        break;
+      case 'jpg':
+      case 'jpeg':
+        $outfunc = 'imagejpeg';
+        break;
+      case 'gif':
+        $outfunc = 'imagegif';
+        break;
+      case 'xpm':
+        $outfunc = 'imagexpm';
+        break;
+      default:
+        imagedestroy($newimage);
+        imagedestroy($oldimage);
+        return false;
+    }
+    
+    // Write output
+    $outfunc($newimage, $out_file);
+    
+    // clean up
+    imagedestroy($newimage);
+    imagedestroy($oldimage);
+    
+    // done!
+    return true;
+  }
+  if ( file_exists($out_file) )
+    return true;
+  return false;
+}
+