code: def _coords_conv(self, pos):
          
          px = (self.original_size[0] / 2 + pos[0]) * self.scale_factor
          py = (self.original_size[1] / 2 - pos[1]) * self.scale_factor
          return round(px, 2), round(py, 2)
docs: For Svg coordinate system, reflect over X axis and
          translate from center to top-left