The cpdf_add_annotation() adds a note with the lower left corner at (llx, lly) and the upper right corner at (urx, ury). Palauttaa TRUE onnistuessaan, muutoin FALSE.
The optional parameter mode determines the unit length. If it is 0 or omitted the default unit as specified for the page is used. Otherwise the coordinates are measured in postscript points disregarding the current unit.