code: def translate_points(self, points):
          
          retval = list()
          append = retval.append
          sx, sy = self.get_center_offset()
          if self._zoom_level == 1.0:
              for c in points:
                  append((c[0] + sx, c[1] + sy))
          else:
              rx = self._real_ratio_x
              ry = self._real_ratio_y
              for c in points:
                  append((int(round((c[0] + sx) * rx)), int(round((c[1] + sy) * ry))))
          return retval
docs: Translate coordinates and return screen coordinates
  
          Will be returned in order passed as tuples.
  
          :return: list