Łatwe tworzenie "watermark" / dodawanie loga w PhpThumb by gxdlabs

W folderze biblioteki PhpThumb odszukujemy folder "thumb_plugins"

Tworzymy plik o nazwie "gd_GdAddLogo_inc.php" //sensu stricte nazwa może być dowolna.

Wewnątrz zapisujemy:

<source lang="php"> <?php /**

* Add logo plugin
* 
* This plugin allows you to add plugin to your image
* 
* @package PhpThumb
* @subpackage Plugins
* @original-author Sergey "hssergey"
* @author Sebastian "DNightmare"
*/

class GdAddLogo {

   /**
    * Instance of GdThumb passed to this class
    * 
    * @var GdThumb
    */
   protected $parentInstance;
   protected $currentDimensions;
   protected $workingImage;
   protected $newImage;
   protected $options;

   /**
    * Add logo to image
    * @param logoFileName - file name of logo image in jpg or png format
    * @param positionX - Position of logo image on X-axis ('left', 'center', 'right' or plain number)
    * @param positionY - Position of logo image on X-axis ('top', 'center', 'bottom' or plain number)
    * @param alpha - alpha value for logo merging in percent
    */
   public function addLogo($logoFileName, $positionX, $positionY, $alpha, &$that) {
       $logo_size                  = getimagesize($logoFileName);
       // bring stuff from the parent class into this class...
       $this->parentInstance       = $that;
       $this->oldImage             = $this->parentInstance->getOldImage();
       $this->parentInstance->setWorkingImage($this->oldImage);
       $this->currentDimensions    = $this->parentInstance->getCurrentDimensions();
       $this->workingImage         = $this->parentInstance->getWorkingImage();
       $this->options              = $this->parentInstance->getOptions();

       $src_dimension              = array(
                                       "x" => $this->currentDimensions['width'], 
                                       "y" => $this->currentDimensions['height']);
       $logo_dimension             = array(
                                       "x" => $logo_size[0],
                                       "y" => $logo_size[1]);

       $center                     = array(
                                       "x" => (($src_dimension["x"] / 2) - ($logo_dimension["x"]/2)),
                                       "y" => (($src_dimension["y"] / 2) - ($logo_dimension["y"]/2)));

       $logo_postionX["left"]      = 0;
       $logo_postionX["center"]    = $center["x"];
       $logo_postionX["right"]     = $src_dimension["x"] - $logo_dimension["x"];
       $logo_postionY["top"]       = 0;
       $logo_postionY["center"]    = $center["y"];
       $logo_postionY["bottom"]    = $src_dimension["y"] - $logo_dimension["y"];

       if(is_numeric($positionX)){ $logo_position["x"] = $positionX; } else { $logo_position["x"] = $logo_postionX[$positionX]; }
       if(is_numeric($positionY)){ $logo_position["y"] = $positionY; } else { $logo_position["y"] = $logo_postionY[$positionY]; }

       switch(exif_imagetype($logoFileName)){
           case IMAGETYPE_JPEG:
               $logo = imagecreatefromjpeg($logoFileName);
               break;
           case IMAGETYPE_PNG:
               $logo = imagecreatefrompng($logoFileName);
               break;
       }

       imagecopy($this->workingImage, $logo, $logo_position["x"], $logo_position["y"], 0, 0, $logo_dimension["x"], $logo_dimension["y"]);
       return $that;
   }

} $pt = PhpThumb::getInstance(); $pt->registerPlugin('GdAddLogo', 'gd'); </source>

Następnie tworzymy stronę testową:

<source lang="php"> $thumb = PhpThumbFactory::create($xxx); // Logo at top-center position 25% visible $thumb->addLogo("./phpthumb_biblioteka/watermark.png", 'right', 'bottom', 100); // Logo at bottom position, 100px from the left side 10% visible // $thumb->addLogo($_SERVER["DOCUMENT_ROOT"]."/images/imageForLogo.png", 'top', 100, 10); $thumb->show(); </source>

$xxx - to ścieżka do obrazka.

Uwaga: Oryginalny skrypt został opublikowany pod adresem : https://github.com/masterexploder/PHPThumb/issues/34 przez użytkownika: DNightmare commented May 30, 2011

w kodzie powyżej zmieniona została metoda imagemerege na imagecopy w celu zachowania przeźroczystości.