🚀 go-pugleaf

Well I'm certainly no expert on this but if all you are trying to do is
'smooth the jaggies', I think I can help.  Consider the pixels in the
original (screen) image.  Any one (except those on the border) can be
connected to 8 other pixels.  When these are converted for the printer
(ie enlarged) the pixels to the "right and left" and "top and bottom"
give smooth lines, only the pixels connected on the diagonals cause
problems.  Since every screen pixel is converted to several printer
pixels the diagonal jumps are exaggerated.  This can be offset by
plotting a extra point between all points connected diagonally.
I'll try to make this even more unclear :-) by 'drawing' a picture.

            +----+----+                         +----+----+

            +----+----+                    +----+----+----+
                                            xxxx xxxx
  +----+----+----+----+               +----+----+----+----+
                                            xxxx xxxx
  +----+----+                         +----+----+----+

  +----+----+                         +----+----+

  Unsmoothed printer pixels           Smoothed printer pixels by
                                      insertions of extra point

It's a bit tricker for the 320x200 CGA mode because generally
color is simulated by using a pattern, and you wouldn't want to
mess up the pseudo-colors by overlaying a extra point on them.

This BTW is similar to what they do with CD players (2x, 4x, 8x
oversampling) to 'improve' there sound.

                                                       Greg