[Sommaire] [Imprimer]

   1  <?php
   2  /**

   3   * This file implements various Image File handling functions.

   4   *

   5   * This file is part of the evoCore framework - {@link http://evocore.net/}

   6   * See also {@link http://sourceforge.net/projects/evocms/}.

   7   *

   8   * @copyright (c)2003-2007 by Francois PLANQUE - {@link http://fplanque.net/}

   9   *

  10   * {@internal License choice

  11   * - If you have received this file as part of a package, please find the license.txt file in

  12   *   the same folder or the closest folder above for complete license terms.

  13   * - If you have received this file individually (e-g: from http://evocms.cvs.sourceforge.net/)

  14   *   then you must choose one of the following licenses before using the file:

  15   *   - GNU General Public License 2 (GPL) - http://www.opensource.org/licenses/gpl-license.php

  16   *   - Mozilla Public License 1.1 (MPL) - http://www.opensource.org/licenses/mozilla1.1.php

  17   * }}

  18   *

  19   * {@internal Open Source relicensing agreement:

  20   * }}

  21   *

  22   * @package evocore

  23   *

  24   * {@internal Below is a list of authors who have contributed to design/coding of this file: }}

  25   * @author fplanque: Francois PLANQUE.

  26   *

  27   * @version $Id: _image.funcs.php,v 1.1 2007/06/25 10:59:57 fplanque Exp $

  28   */
  29  if( !defined('EVO_MAIN_INIT') ) die( 'Please, do not access this page directly.' );
  30  
  31  
  32  /**

  33   * Scale dimensions to fit into a constrained size, while preserving aspect ratio.

  34   *

  35   * @param integer source width

  36   * @param integer source height

  37   * @param integer constrained width

  38   * @param integer constrained height

  39   */
  40  function scale_to_constraint( $src_width, $src_height, $max_width, $max_height )
  41  {
  42      $src_ratio = $src_width / $src_height;
  43      if( $max_width / $max_height <= $src_ratio )
  44      {
  45          $width = $max_width;
  46          $height = (int)round( $max_width / $src_ratio );
  47      }
  48      else
  49      {
  50          $width = (int)round( $max_height * $src_ratio );
  51          $height = $max_height;
  52      }
  53  
  54      return array( $width, $height );
  55  }
  56  
  57  
  58  /**

  59   * Scale dimensions to fit into a constrained size, while preserving aspect ratio.

  60   * The scaling only happens if the source is larger than the constraint.

  61   *

  62   * @param integer source width

  63   * @param integer source height

  64   * @param integer constrained width

  65   * @param integer constrained height

  66   */
  67  function fit_into_constraint( $src_width, $src_height, $max_width, $max_height )
  68  {
  69      if( $src_width > $max_width || $src_height > $max_height )
  70      {
  71          return scale_to_constraint( $src_width, $src_height, $max_width, $max_height );
  72      }
  73  
  74      return array( $src_width, $src_height );
  75  }
  76  
  77  
  78  /**

  79   * Load an image from a file into memory

  80   *

  81   * @param string pathname of image file

  82   * @param string

  83   * @return array resource image handle or NULL

  84   */
  85  function load_image( $path, $mimetype )
  86  {
  87      $err = NULL;
  88      $err_info = NULL;
  89      $imh = NULL;
  90  
  91      switch( $mimetype )
  92      {
  93          case 'image/jpeg':
  94              $imh = imagecreatefromjpeg( $path ); // dh> TODO: this can fail, if $path is not a valid jpeg! Handle this.

  95              break;
  96  
  97          case 'image/gif':
  98              $imh = imagecreatefromgif( $path );  // dh> TODO: this can fail, if $path is not a valid gif! Handle this.

  99              break;
 100  
 101           default:
 102              // Unrecognized mime type

 103              $err = 'Emime';    // Sort error code

 104              $err_info = $mimetype;
 105              break;
 106      }
 107  
 108      return array( $err, $err_info, $imh );
 109  }
 110  
 111  
 112  /**

 113   * Output an image from memory to web client

 114   *

 115   * @param resource image handle

 116   * @param string pathname of image file

 117   * @param string

 118   * @param integer

 119   * @param string permissions

 120   * @return string

 121   */
 122  function save_image( $imh, $path, $mimetype, $quality = 90, $chmod = NULL )
 123  {
 124      $err = NULL;
 125  
 126      switch( $mimetype )
 127      {
 128          case 'image/jpeg':
 129              imagejpeg( $imh, $path, $quality );
 130              break;
 131  
 132          case 'image/gif':
 133              imagegif( $imh, $path );
 134              break;
 135  
 136           default:
 137              // Unrecognized mime type

 138              $err = 'Emime';    // Sort error code

 139              break;
 140      }
 141  
 142      if( empty( $err ) )
 143      {
 144          // Make sure the file has the default permissions we want:

 145          if( $chmod === NULL )
 146          {
 147              global $Settings;
 148              $chmod = $Settings->get('fm_default_chmod_file');
 149          }
 150          chmod( $path, octdec( $chmod ) );
 151      }
 152  
 153      return $err;
 154  }
 155  
 156  
 157  /**

 158   * Output an image from memory to web client

 159   *

 160   * @param resource image handle

 161   * @param string

 162   * @return string

 163   */
 164  function output_image( $imh, $mimetype )
 165  {
 166      $err = NULL;
 167  
 168      switch( $mimetype )
 169      {
 170          case 'image/jpeg':
 171              header('Content-type: '.$mimetype );
 172              imagejpeg( $imh );
 173              break;
 174  
 175          case 'image/gif':
 176              header('Content-type: '.$mimetype );
 177              imagegif( $imh );
 178              break;
 179  
 180           default:
 181              // Unrecognized mime type

 182              $err = 'Emime';    // Sort error code

 183              break;
 184      }
 185  
 186      return $err;
 187  }
 188  
 189  
 190  
 191  
 192  /**

 193   * Generate a thumbnail

 194   *

 195   * @return array short error code + dest image handler

 196   */
 197  function generate_thumb( $src_imh, $thumb_width, $thumb_height )
 198  {
 199      $src_width = imagesx( $src_imh ) ;
 200      $src_height = imagesy( $src_imh );
 201  
 202      if( $src_width <= $thumb_width && $src_height <= $thumb_height )
 203      {    // There is no need to resample, use original!
 204          return array( NULL, $src_imh );
 205      }
 206  
 207      list( $dest_width, $dest_height ) = scale_to_constraint( $src_width, $src_height, $thumb_width, $thumb_height );
 208  
 209      // pre_dump( $src_width, $src_height, $dest_width, $dest_height );

 210  
 211      $dest_imh = imagecreatetruecolor( $dest_width, $dest_height ); // Create a black image

 212      if( ! imagecopyresampled( $dest_imh, $src_imh, 0, 0, 0, 0, $dest_width, $dest_height, $src_width, $src_height ) )
 213      {
 214          return array( 'Eresample', $dest_imh );
 215      }
 216  
 217      // TODO: imageinterlace();

 218  
 219      return array( NULL, $dest_imh );
 220  }
 221  
 222  /*

 223   * $Log: _image.funcs.php,v $

 224   * Revision 1.1  2007/06/25 10:59:57  fplanque

 225   * MODULES (refactored MVC)

 226   *

 227   * Revision 1.9  2007/05/28 11:28:22  fplanque

 228   * file perm fix / thumbnails

 229   *

 230   * Revision 1.8  2007/04/26 00:11:10  fplanque

 231   * (c) 2007

 232   *

 233   * Revision 1.7  2007/03/20 07:39:08  fplanque

 234   * filemanager fixes, including the chmod octal stuff

 235   *

 236   * Revision 1.6  2007/03/08 00:22:35  blueyed

 237   * TODO

 238   *

 239   * Revision 1.5  2007/01/19 08:20:36  fplanque

 240   * Addressed resized image quality.

 241   *

 242   * Revision 1.4  2006/12/13 22:43:24  fplanque

 243   * default perms for newly created thumbnails

 244   *

 245   * Revision 1.3  2006/12/13 21:23:56  fplanque

 246   * .evocache folders / saving of thumbnails

 247   *

 248   * Revision 1.2  2006/12/13 20:10:31  fplanque

 249   * object responsibility delegation?

 250   *

 251   * Revision 1.1  2006/12/13 18:10:21  fplanque

 252   * thumbnail resampling proof of concept

 253   *

 254   */
 255  ?>