Method and apparatus for adaptive forward differencing in therendering of curves and surfaces

Abstract From the Canadian patent

An adaptive forward differencing apparatus is disclosed, wherein, when rendering curves calculated x, y values, are increased or decreased in order to create values which correspond to the next pixel of the display CRT such that curves, of substantially one pixel increments are continuously and uniformly generated. The apparatus of the present invention also provides circuitry for generating coordinates of display elements which apporximate an ideal vector and to define curves vectors or objects whthin maximum and minimum coordinates of the CRT display. The present invention also provides efficient circuitry for computing the value of l/w of the homogenous coordinate w.