# File lib/pdf/reader/page_state.rb, line 209
      def trm_transform(x, y, z = 1)
        trm = text_rendering_matrix
        [
          (trm[0,0] * x) + (trm[1,0] * y) + (trm[2,0] * z),
          (trm[0,1] * x) + (trm[1,1] * y) + (trm[2,1] * z)
        ]
      end