[Gnuplot-bugs] postscript PolyFill gives gs rounding errors

[Carl T. <car...@ed...>]

Hi all,
I noticed that with filledcurves on the postscript terminal the filled
area can be quite different from what it's supposed to be, at least when
viewed in gv. The outline of the area is drawn as a separate line which
is in the right place. The line drawing code switches between relative
and absolute coordinates to keep rounding errors down, but the PolyFill
code does not. So I've attached a small patch that makes PolyFill
generate the exact same sequence of lineto/rlineto as the line drawing
code in PS_vector.

Also, it's not obvious to me why filledcurves should draw a line around
the area that it fills - can this line ever be made to have a different
color, or is its only effect to contribute half a linewidth to the drawn
area? If the line should be there, maybe it could be made to reuse the
(r)lineto commands used for Polyfill? (In some cases this would
substantially reduce the size of the output file.)

Cheers,
//Carl

-- 
   Carl Troein - car...@ed...
   http://carl.troein.com/