function __construct($map, $orientation, $units, $format, $pdfSettings, $prefmap = true, $layers) {
        parent::__construct($orientation, $units, $format, true, $encoding = 'ISO-8859-1');

        // only for tcpdf version >= 3
        // - font not well defined --> errors
        // - header and footer printed = lines on top and bottom
        $this->setPrintHeader(false);
        $this->setPrintFooter(false);

        $mapW = $pdfSettings['width'];
        $mapH = $pdfSettings['height'];

        $this->pdfSettings = $pdfSettings;
        $this->prefmap = $prefmap;

        foreach ($layers as $l) {

            // this function init all position parameters, legend, ...
            $this->initDimensions($mapW, $mapH);

            // add layer
            $_SESSION["groups"] = array();
            $_SESSION["groups"][] = $l['name'];

            // set scale
            $scale = $l['scale'] * 1; //*1 because it comes as string
            $printScale = $scale;

            // printmap creation done in derivated classes :
            $this->createPrintMap($map, $mapW, $mapH, $printScale, 'pdf', 144, false, false, $pdfSettings);

            // avoid bad title
            $title = $pdfSettings['printtitle'] ? $pdfSettings['printtitle'] : $pdfSettings['pdftitle'];
            $this->initPDF($pdfSettings['author'], $title, $pdfSettings['defFont'], $pdfSettings['defFontSize']);
            $this->printPDF($map, $mapW, $mapH, $this->printUrlList, $printScale, $l);
        }
    }