/* Determine the necessary scaling factor to avoid quality degradation in
the center of the screen. */
- float horiz_oversize = distort((fill_factor-lens_separation)*2)-eye_offset;
+ float horiz_oversize = distort((fill_factor-lens_separation)*2)/((fill_factor-lens_separation)*2)-eye_offset;
float vert_oversize = distort(1.25f*fill_factor)/(1.25f*fill_factor);
oversize = min(horiz_oversize, vert_oversize);