1 <?php

     2 // $Id: image.inc,v 1.24 2008/01/28 16:05:17 goba Exp $

     3 

     4 /**

     5  * @file

     6  * API for manipulating images.

     7  */

     8 

     9 /**

    10  * @defgroup image Image toolkits

    11  * @{

    12  * Drupal's image toolkits provide an abstraction layer for common image file

    13  * manipulations like scaling, cropping, and rotating. The abstraction frees

    14  * module authors from the need to support multiple image libraries, and it

    15  * allows site administrators to choose the library that's best for them.

    16  *

    17  * PHP includes the GD library by default so a GD toolkit is installed with

    18  * Drupal. Other toolkits like ImageMagic are available from contrib modules.

    19  * GD works well for small images, but using it with larger files may cause PHP

    20  * to run out of memory. In contrast the ImageMagick library does not suffer

    21  * from this problem, but it requires the ISP to have installed additional

    22  * software.

    23  *

    24  * Image toolkits are installed by copying the image.ToolkitName.inc file into

    25  * Drupal's includes directory. The toolkit must then be enabled using the

    26  * admin/settings/image-toolkit form.

    27  *

    28  * Only one toolkit maybe selected at a time. If a module author wishes to call

    29  * a specific toolkit they can check that it is installed by calling

    30  * image_get_available_toolkits(), and then calling its functions directly.

    31  */

    32 

    33 /**

    34  * Return a list of available toolkits.

    35  *

    36  * @return

    37  *   An array of toolkit name => descriptive title.

    38  */

    39 function image_get_available_toolkits() {

    40   $toolkits = file_scan_directory('includes', 'image\..*\.inc$');

    41 

    42   $output = array();

    43   foreach ($toolkits as $file => $toolkit) {

    44     include_once "./$file";

    45     $function = str_replace('.', '_', $toolkit->name) .'_info';

    46     if (function_exists($function)) {

    47       $info = $function();

    48       $output[$info['name']] = $info['title'];

    49     }

    50   }

    51 

    52   return $output;

    53 }

    54 

    55 /**

    56  * Retrieve the name of the currently used toolkit.

    57  *

    58  * @return

    59  *   String containing the name of the selected toolkit, or FALSE on error.

    60  */

    61 function image_get_toolkit() {

    62   static $toolkit;

    63 

    64   if (!$toolkit) {

    65     $toolkit = variable_get('image_toolkit', 'gd');

    66     $toolkit_file = './includes/image.'. $toolkit .'.inc';

    67     if (isset($toolkit) && file_exists($toolkit_file)) {

    68       include_once $toolkit_file;

    69     }

    70     elseif (!image_gd_check_settings()) {

    71       $toolkit = FALSE;

    72     }

    73   }

    74 

    75   return $toolkit;

    76 }

    77 

    78 /**

    79  * Invokes the given method using the currently selected toolkit.

    80  *

    81  * @param $method

    82  *   A string containing the method to invoke.

    83  * @param $params

    84  *   An optional array of parameters to pass to the toolkit method.

    85  * @return

    86  *   Mixed values (typically Boolean indicating successful operation).

    87  */

    88 function image_toolkit_invoke($method, $params = array()) {

    89   if ($toolkit = image_get_toolkit()) {

    90     $function = 'image_'. $toolkit .'_'. $method;

    91     if (function_exists($function)) {

    92       return call_user_func_array($function, $params);

    93     }

    94     else {

    95       watchdog('php', 'The selected image handling toolkit %toolkit can not correctly process %function.', array('%toolkit' => $toolkit, '%function' => $function), WATCHDOG_ERROR);

    96       return FALSE;

    97     }

    98   }

    99 }

   100 

   101 

   102 /**

   103  * Get details about an image.

   104  *

   105  * Drupal only supports GIF, JPG and PNG file formats.

   106  *

   107  * @return

   108  *   FALSE, if the file could not be found or is not an image. Otherwise, a

   109  *   keyed array containing information about the image:

   110  *    'width'     - Width in pixels.

   111  *    'height'    - Height in pixels.

   112  *    'extension' - Commonly used file extension for the image.

   113  *    'mime_type' - MIME type ('image/jpeg', 'image/gif', 'image/png').

   114  *    'file_size' - File size in bytes.

   115  */

   116 function image_get_info($file) {

   117   if (!is_file($file)) {

   118     return FALSE;

   119   }

   120 

   121   $details = FALSE;

   122   $data = @getimagesize($file);

   123   $file_size = @filesize($file);

   124 

   125   if (isset($data) && is_array($data)) {

   126     $extensions = array('1' => 'gif', '2' => 'jpg', '3' => 'png');

   127     $extension = array_key_exists($data[2], $extensions) ?  $extensions[$data[2]] : '';

   128     $details = array('width'     => $data[0],

   129                      'height'    => $data[1],

   130                      'extension' => $extension,

   131                      'file_size' => $file_size,

   132                      'mime_type' => $data['mime']);

   133   }

   134 

   135   return $details;

   136 }

   137 

   138 /**

   139  * Scales an image to the exact width and height given. Achieves the

   140  * target aspect ratio by cropping the original image equally on both

   141  * sides, or equally on the top and bottom.  This function is, for

   142  * example, useful to create uniform sized avatars from larger images.

   143  *

   144  * The resulting image always has the exact target dimensions.

   145  *

   146  * @param $source

   147  *   The file path of the source image.

   148  * @param $destination

   149  *   The file path of the destination image.

   150  * @param $width

   151  *   The target width, in pixels.

   152  * @param $height

   153  *   The target height, in pixels.

   154  * @return

   155  *   TRUE or FALSE, based on success.

   156  */

   157 function image_scale_and_crop($source, $destination, $width, $height) {

   158   $info = image_get_info($source);

   159 

   160   $scale = max($width / $info['width'], $height / $info['height']);

   161   $x = round(($info['width'] * $scale - $width) / 2);

   162   $y = round(($info['height'] * $scale - $height) / 2);

   163 

   164   if (image_toolkit_invoke('resize', array($source, $destination, $info['width'] * $scale, $info['height'] * $scale))) {

   165     return image_toolkit_invoke('crop', array($destination, $destination, $x, $y, $width, $height));

   166   }

   167   return FALSE;

   168 }

   169 

   170 /**

   171  * Scales an image to the given width and height while maintaining aspect

   172  * ratio.

   173  *

   174  * The resulting image can be smaller for one or both target dimensions.

   175  *

   176  * @param $source

   177  *   The file path of the source image.

   178  * @param $destination

   179  *   The file path of the destination image.

   180  * @param $width

   181  *   The target width, in pixels.

   182  * @param $height

   183  *   The target height, in pixels.

   184  * @return

   185  *   TRUE or FALSE, based on success.

   186  */

   187 function image_scale($source, $destination, $width, $height) {

   188   $info = image_get_info($source);

   189 

   190   // Don't scale up.

   191   if ($width >= $info['width'] && $height >= $info['height']) {

   192     return FALSE;

   193   }

   194 

   195   $aspect = $info['height'] / $info['width'];

   196   if ($aspect < $height / $width) {

   197     $width = (int)min($width, $info['width']);

   198     $height = (int)round($width * $aspect);

   199   }

   200   else {

   201     $height = (int)min($height, $info['height']);

   202     $width = (int)round($height / $aspect);

   203   }

   204 

   205   return image_toolkit_invoke('resize', array($source, $destination, $width, $height));

   206 }

   207 

   208 /**

   209  * Resize an image to the given dimensions (ignoring aspect ratio).

   210  *

   211  * @param $source

   212  *   The file path of the source image.

   213  * @param $destination

   214  *   The file path of the destination image.

   215  * @param $width

   216  *   The target width, in pixels.

   217  * @param $height

   218  *   The target height, in pixels.

   219   * @return

   220  *   TRUE or FALSE, based on success.

   221  */

   222 function image_resize($source, $destination, $width, $height) {

   223   return image_toolkit_invoke('resize', array($source, $destination, $width, $height));

   224 }

   225 

   226 /**

   227  * Rotate an image by the given number of degrees.

   228  *

   229  * @param $source

   230  *   The file path of the source image.

   231  * @param $destination

   232  *   The file path of the destination image.

   233  * @param $degrees

   234  *   The number of (clockwise) degrees to rotate the image.

   235  * @param $background

   236  *   An hexidecimal integer specifying the background color to use for the

   237  *   uncovered area of the image after the rotation. E.g. 0x000000 for black,

   238  *   0xff00ff for magenta, and 0xffffff for white.

   239  * @return

   240  *   TRUE or FALSE, based on success.

   241  */

   242 function image_rotate($source, $destination, $degrees, $background = 0x000000) {

   243   return image_toolkit_invoke('rotate', array($source, $destination, $degrees, $background));

   244 }

   245 

   246 /**

   247  * Crop an image to the rectangle specified by the given rectangle.

   248  *

   249  * @param $source

   250  *   The file path of the source image.

   251  * @param $destination

   252  *   The file path of the destination image.

   253  * @param $x

   254  *   The top left co-ordinate, in pixels, of the crop area (x axis value).

   255  * @param $y

   256  *   The top left co-ordinate, in pixels, of the crop area (y axis value).

   257  * @param $width

   258  *   The target width, in pixels.

   259  * @param $height

   260  *   The target height, in pixels.

   261  * @return

   262  *   TRUE or FALSE, based on success.

   263  */

   264 function image_crop($source, $destination, $x, $y, $width, $height) {

   265   return image_toolkit_invoke('crop', array($source, $destination, $x, $y, $width, $height));

   266 }

   267 

   268 /**

   269  * @} End of "defgroup image".

   270  */