this.page = page;
PdfArray baseDataObject = getBaseDataObject();
double pageHeight = page.getBox().getHeight();
baseDataObject.add(new PdfReal(start.getX()));
baseDataObject.add(new PdfReal(pageHeight - start.getY()));
baseDataObject.add(new PdfReal(knee.getX()));
baseDataObject.add(new PdfReal(pageHeight - knee.getY()));
baseDataObject.add(new PdfReal(end.getX()));
baseDataObject.add(new PdfReal(pageHeight - end.getY()));
}