[Summary view] [Print] [Text view]

   1  <?php
   2  // $Id: image.gd.inc,v 1.4 2008/01/15 10:17:42 goba Exp $
   3  
   4  /**
   5   * @file
   6   * GD2 toolkit for image manipulation within Drupal.
   7   */
   8  
   9  /**
  10   * @ingroup image
  11   * @{
  12   */
  13  
  14  /**
  15   * Retrieve information about the toolkit.
  16   */
  17  function image_gd_info() {
  18    return array('name' => 'gd', 'title' => t('GD2 image manipulation toolkit'));
  19  }
  20  
  21  /**
  22   * Retrieve settings for the GD2 toolkit.
  23   */
  24  function image_gd_settings() {
  25    if (image_gd_check_settings()) {
  26      $form = array();
  27      $form['status'] = array(
  28        '#value' => t('The GD toolkit is installed and working properly.')
  29      );
  30  
  31      $form['image_jpeg_quality'] = array(
  32        '#type' => 'textfield',
  33        '#title' => t('JPEG quality'),
  34        '#description' => t('Define the image quality for JPEG manipulations. Ranges from 0 to 100. Higher values mean better image quality but bigger files.'),
  35        '#size' => 10,
  36        '#maxlength' => 3,
  37        '#default_value' => variable_get('image_jpeg_quality', 75),
  38        '#field_suffix' => t('%'),
  39      );
  40      $form['#element_validate'] = array('image_gd_settings_validate');
  41      
  42      return $form;
  43    }
  44    else {
  45      form_set_error('image_toolkit', t('The GD image toolkit requires that the GD module for PHP be installed and configured properly. For more information see <a href="@url">PHP\'s image documentation</a>.', array('@url' => 'http://php.net/image')));
  46      return FALSE;
  47    }
  48  }
  49  
  50  /**
  51   * Validate the submitted GD settings.
  52   */
  53  function image_gd_settings_validate($form, &$form_state) {
  54    // Validate image quality range.
  55    $value = $form_state['values']['image_jpeg_quality'];
  56    if (!is_numeric($value) || $value < 0 || $value > 100) {
  57      form_set_error('image_jpeg_quality', t('JPEG quality must be a number between 0 and 100.'));
  58    }
  59  }
  60  
  61  /**
  62   * Verify GD2 settings (that the right version is actually installed).
  63   *
  64   * @return
  65   *   A boolean indicating if the GD toolkit is avaiable on this machine.
  66   */
  67  function image_gd_check_settings() {
  68    if ($check = get_extension_funcs('gd')) {
  69      if (in_array('imagegd2', $check)) {
  70        // GD2 support is available.
  71        return TRUE;
  72      }
  73    }
  74    return FALSE;
  75  }
  76  
  77  /**
  78   * Scale an image to the specified size using GD.
  79   */
  80  function image_gd_resize($source, $destination, $width, $height) {
  81    if (!file_exists($source)) {
  82      return FALSE;
  83    }
  84  
  85    $info = image_get_info($source);
  86    if (!$info) {
  87      return FALSE;
  88    }
  89  
  90    $im = image_gd_open($source, $info['extension']);
  91    if (!$im) {
  92      return FALSE;
  93    }
  94  
  95    $res = imagecreatetruecolor($width, $height);
  96    if ($info['extension'] == 'png') {
  97      $transparency = imagecolorallocatealpha($res, 0, 0, 0, 127);
  98      imagealphablending($res, FALSE);
  99      imagefilledrectangle($res, 0, 0, $width, $height, $transparency);
 100      imagealphablending($res, TRUE);
 101      imagesavealpha($res, TRUE);
 102    }
 103    elseif ($info['extension'] == 'gif') {
 104      // If we have a specific transparent color.
 105      $transparency_index = imagecolortransparent($im);
 106      if ($transparency_index >= 0) {
 107        // Get the original image's transparent color's RGB values.
 108        $transparent_color = imagecolorsforindex($im, $transparency_index);
 109        // Allocate the same color in the new image resource.
 110        $transparency_index = imagecolorallocate($res, $transparent_color['red'], $transparent_color['green'], $transparent_color['blue']);
 111        // Completely fill the background of the new image with allocated color.
 112        imagefill($res, 0, 0, $transparency_index);
 113        // Set the background color for new image to transparent.
 114        imagecolortransparent($res, $transparency_index);
 115        // Find number of colors in the images palette.
 116        $number_colors = imagecolorstotal($im);
 117        // Convert from true color to palette to fix transparency issues.
 118        imagetruecolortopalette($res, TRUE, $number_colors);
 119      }
 120    }
 121    imagecopyresampled($res, $im, 0, 0, 0, 0, $width, $height, $info['width'], $info['height']);
 122    $result = image_gd_close($res, $destination, $info['extension']);
 123  
 124    imagedestroy($res);
 125    imagedestroy($im);
 126  
 127    return $result;
 128  }
 129  
 130  /**
 131   * Rotate an image the given number of degrees.
 132   */
 133  function image_gd_rotate($source, $destination, $degrees, $background = 0x000000) {
 134    if (!function_exists('imageRotate')) {
 135      return FALSE;
 136    }
 137  
 138    $info = image_get_info($source);
 139    if (!$info) {
 140      return FALSE;
 141    }
 142  
 143    $im = image_gd_open($source, $info['extension']);
 144    if (!$im) {
 145      return FALSE;
 146    }
 147  
 148    $res = imageRotate($im, $degrees, $background);
 149    $result = image_gd_close($res, $destination, $info['extension']);
 150  
 151    return $result;
 152  }
 153  
 154  /**
 155   * Crop an image using the GD toolkit.
 156   */
 157  function image_gd_crop($source, $destination, $x, $y, $width, $height) {
 158    $info = image_get_info($source);
 159    if (!$info) {
 160      return FALSE;
 161    }
 162  
 163    $im = image_gd_open($source, $info['extension']);
 164    $res = imageCreateTrueColor($width, $height);
 165    imageCopy($res, $im, 0, 0, $x, $y, $width, $height);
 166    $result = image_gd_close($res, $destination, $info['extension']);
 167  
 168    imageDestroy($res);
 169    imageDestroy($im);
 170  
 171    return $result;
 172  }
 173  
 174  /**
 175   * GD helper function to create an image resource from a file.
 176   *
 177   * @param $file
 178   *   A string file path where the iamge should be saved.
 179   * @param $extension
 180   *   A string containing one of the following extensions: gif, jpg, jpeg, png.
 181   * @return
 182   *   An image resource, or FALSE on error.
 183   */
 184  function image_gd_open($file, $extension) {
 185    $extension = str_replace('jpg', 'jpeg', $extension);
 186    $open_func = 'imageCreateFrom'. $extension;
 187    if (!function_exists($open_func)) {
 188      return FALSE;
 189    }
 190    return $open_func($file);
 191  }
 192  
 193  /**
 194   * GD helper to write an image resource to a destination file.
 195   *
 196   * @param $res
 197   *   An image resource created with image_gd_open().
 198   * @param $destination
 199   *   A string file path where the iamge should be saved.
 200   * @param $extension
 201   *   A string containing one of the following extensions: gif, jpg, jpeg, png.
 202   * @return
 203   *   Boolean indicating success.
 204   */
 205  function image_gd_close($res, $destination, $extension) {
 206    $extension = str_replace('jpg', 'jpeg', $extension);
 207    $close_func = 'image'. $extension;
 208    if (!function_exists($close_func)) {
 209      return FALSE;
 210    }
 211    if ($extension == 'jpeg') {
 212      return $close_func($res, $destination, variable_get('image_jpeg_quality', 75));
 213    }
 214    else {
 215      return $close_func($res, $destination);
 216    }
 217  }
 218  
 219  /**
 220   * @} End of "ingroup image".
 221   */