Re: Postscript printer errors with rounded barlines?

[Todd Lewis]

> On Sat, Jul 23, 2011 at 7:45 PM, Jan Warchoł wrote:
>
>> I'm not experienced with PostScript, but i have an impression that
>> this may be related to an issue discussed earlier - see here
>> http://lists.gnu.org/archive/html/lilypond-user/2007-07/msg00485.html
>> and here
>> http://lists.gnu.org/archive/html/lilypond-devel/2007-07/msg00072.html
>> I see that something about draw_round_box was said there...
>
> I think this is an other issue.  Due to rounding, PDF viewers can err
> the placement of the barline by a pixel. This is insolvable, as there
> is no way to hint that the barline should coincide with the staffline,
> yet we need to go the end of the barline to get the correct effect in
> the corners in staves.
>
> The one-pixel error is very noticeable on-screen due to
> low-resolution, but on a 1200dpi printer,  a single dot error is about
> 0.02 mm, ie. not noticeable.

I can assure you this is the same issue and not a rounding error. I've also
found a way to reliably reproduce the problem, and a work-around. I've always
been frustrated that my printed output has these huge bar lines, while the
on-screen preview (evince on Ubuntu) looks fine. I've found that if I preview in
evince (where it looks good), select File->Print and print to a .ps file, then
open that .ps file in evince, the bar lines have become obnoxiously fat again.

The work-around is to change /draw_round_box in ps/music-drawing-routines.ps as
indicated in prior emails to avoid rectstroke with a 0.0 linewidth, the behavior
of which is device dependent.

After applying that fix tonight, I have for the first time produce printed (on
paper) bar lines thinner than 1pt, and I am very happy.


Now, if I can just find a way to left-align the first lyrics in each system I'll
have nothing left to complain about. :)
--
Todd