<?php
	/*
		Run-time JPEG converter

		Requires ImageMagick and GD

		Code by Alex Dunae (dunae.ca)

		Params:
			src     -  Relative path to the source image (JPEG only)
			mode    -  feed/inline/thumb

	*/

	require('common.php');

	ob_start();

	if(!function_exists('imagecreatefromjpeg')) exit_with_error('GD library is required to process images');

	// define imagemagick conversion formats - these should also be defined
	// in your .htaccess file
	$conversions = array(
		'feed' => "convert %1\$s -antialias -resize 150x %2\$s",
		'thumb' => "convert %1\$s -antialias -resize 45x %2\$s",
		'gallery' => "convert %1\$s -antialias -resize 400x %2\$s"
	);

	$mode = @$_REQUEST['mode'];
	if(empty($mode) || !array_key_exists($mode, $conversions)) exit_with_error('Valid mode is required');

	// get the path to file to be processed
	$src = get_file_from_querystring();

	// create the cache file name
	$target = get_cache_file_name($src, $mode);

	// if possible, display the image from cache
	if(file_exists($target)) {
		if($image_handle = imagecreatefromjpeg($target)) display_image_and_exit($image_handle);
		exit(0);
	}

	// run the imagemagick conversion
	$cmd = sprintf($conversions[$mode], escapeshellarg($src), escapeshellarg($target));

	$convert = system($cmd, $ret);

	// on success, display converted img
	// otherwise display the src file
	if($ret < 2) {
		if($image_handle = @imagecreatefromjpeg($target)) display_image_and_exit($image_handle);
	} else {
		if($image_handle = @imagecreatefromjpeg($src)) display_image_and_exit($image_handle);
	}

	exit(0);

	function display_image_and_exit($image_handle) {
		ob_clean();
		header('Content-type: image/jpeg');
		imagejpeg($image_handle);
		ob_flush();
		imagedestroy($image_handle);
		exit(0);
	}
?>