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