#!/usr/bin/php
<?php

/*  PEL: PHP Exif Library.  A library with support for reading and
 *  writing all Exif headers in JPEG and TIFF images using PHP.
 *
 *  Copyright (C) 2006, 2007  Martin Geisler.
 *
 *  This program is free software; you can redistribute it 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 more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program in the file COPYING; if not, write to the
 *  Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 *  Boston, MA 02110-1301 USA
 */

/* $Id$ */

/* Error reporting is good.  Having PHP report all errors means that
 * one finds programming errors more quickly. */
error_reporting(E_ALL);

/* a printf() variant that appends a newline to the output. */
function println(/* fmt, args... */) {
    $args = func_get_args();
    $fmt = array_shift($args);
    vprintf($fmt . "\n", $args);
}


/* Make PEL speak the users language, if it is available. */
setlocale(LC_ALL, '');

/* Load the required PEL files for handling JPEG images. */
require_once(dirname(__FILE__) . '/../PelJpeg.php');

/* Store the name of the script in $prog and remove this first part of
 * the command line. */
$prog = array_shift($argv);
$error = false;

/* The next argument could be -d to signal debug mode where lots of
 * extra information is printed out when the image is parsed. */
if (isset($argv[0]) && $argv[0] == '-d') {
  Pel::$debug = true;
  array_shift($argv);
}

/* The mandatory input filename. */
if (isset($argv[0])) {
  $input = array_shift($argv);
} else {
  $error = true;
}

/* The mandatory output filename. */
if (isset($argv[0])) {
  $output = array_shift($argv);
} else {
  $error = true;
}

/* The mandatory scale factor. */
if (isset($argv[0])) {
  $scale = array_shift($argv);
} else {
  $error = true;
}


/* Usage information is printed if an error was found in the command
 * line arguments. */
if ($error) {
  println('Usage: %s [-d] <input> <output> <scale>', $prog);
  println('Optional arguments:');
  println('  -d    turn debug output on.');
  println('Mandatory arguments:');
  println('  input   the input filename, a JPEG image.');
  println('  output  filename for saving the changed image.');
  println('  scale   scale factor, say 0.5 to resize to half the ' .
          'original size.');
  exit(1);
}

/* The input file is now loaded into a PelJpeg object. */
println('Reading file "%s".', $input);
$input_jpeg = new PelJpeg($input);

/* The input image is already loaded, so we can reuse the bytes stored
 * in $input_jpeg when creating the Image resource. */
$original = ImageCreateFromString($input_jpeg->getBytes());
$original_w = ImagesX($original);
$original_h = ImagesY($original);

$scaled_w = $original_w * $scale;
$scaled_h = $original_h * $scale;

/* Now create the scaled image. */
$scaled = ImageCreateTrueColor($scaled_w, $scaled_h);
ImageCopyResampled($scaled, $original,
                   0, 0, /* dst (x,y) */
                   0, 0, /* src (x,y) */
                   $scaled_w, $scaled_h,
                   $original_w, $original_h);

/* We want the raw JPEG data from $scaled. Luckily, one can create a
 * PelJpeg object from an image resource directly: */
$output_jpeg = new PelJpeg($scaled);

/* Retrieve the original Exif data in $jpeg (if any). */
$exif = $input_jpeg->getExif();

/* If no Exif data was present, then $exif is null. */
if ($exif != null)
  $output_jpeg->setExif($exif);

/* We can now save the scaled image. */
println('Writing file "%s".', $output);
$output_jpeg->saveFile($output);

/* The End. */
?>