Re: Cairo plans

[Thomas Morley]

Am Mi., 1. Sept. 2021 um 16:25 Uhr schrieb Jean Abou Samra <jean@abou-samra.fr>:
>
> Le 01/09/2021 à 15:11, Rene Brandenburger a écrit :
> > I use the \postscript a lot when typesetting contemporary music e.g.
> > like this:
> >
> > \version "2.20.0"
> >
> >
> > wave_line = \markup {
> >   \with-dimensions #'(0 . 0) #'(0 . 0)
> >   \postscript #"0.3 setlinewidth 1 setlinecap [0 1]
> >  0 0 0 setrgbcolor  0.00 -3.50 moveto
> >  0.23 -3.71   0.47 -3.93   1.00 -4.00 curveto
> >  1.53 -4.07   2.36 -4.00   3.00 -3.50 curveto
> >  3.64 -3.00   4.11 -2.07   4.50 -1.46 curveto
> >  4.89 -0.84   5.22 -0.55   6.00 -0.80 curveto
> >  6.78 -1.05   8.03 -1.83   9.00 -1.53 curveto
> >  9.97 -1.23  10.66  0.15  11.50  0.50 curveto
> > 12.34  0.85  13.32  0.17  14.00 -0.50 curveto
> > 14.68 -1.17  15.05 -1.84  16.00 -2.50 curveto
> > 16.95 -3.16  18.47 -3.82  20.00 -4.49 curveto
> > stroke "
> > }
> >
> >  \relative c''{
> >   s1*5^\wave_line
> > }
>
>
> This use case continues to be supported with
> Cairo. Just convert \postscript to \path, wich
> works both in the current PS backend and with Cairo.
>
> \version "2.22.1"
>
> wave_line = \markup {
>    \with-dimensions #'(0 . 0) #'(0 . 0)
>    \path #0.5
>          #'((moveto 0.00 -3.50)
>             (curveto 0.23 -3.71 0.47 -3.93 1.00 -4.00)
>             (curveto 1.53 -4.07 2.36 -4.00 3.00 -3.50)
>             (curveto 3.64 -3.00  4.11 -2.07 4.50 -1.46)
>             (curveto 4.89 -0.84 5.22 -0.55 6.00 -0.80)
>             (curveto 6.78 -1.05 8.03 -1.83 9.00 -1.53)
>             (curveto 9.97 -1.23  10.66 0.15 11.50 0.50)
>             (curveto 12.34  0.85  13.32 0.17 14.00 -0.50)
>             (curveto 14.68 -1.17 15.05 -1.84 16.00 -2.50)
>             (curveto 16.95 -3.16  18.47 -3.82 20.00 -4.49))
> }
>
> { s1*5^\wave_line }
>
> Actually, this is better in any case, because from
> \path LilyPond is able to get extents and "skylines"
> (outlines). Try:
>
> \version "2.22.1"
>
> #(ly:set-option 'debug-skylines)
>
> wave_line = \markup
>    \path #0.5
>          #'((moveto 0.00 -3.50)
>             (curveto 0.23 -3.71 0.47 -3.93 1.00 -4.00)
>             (curveto 1.53 -4.07 2.36 -4.00 3.00 -3.50)
>             (curveto 3.64 -3.00  4.11 -2.07 4.50 -1.46)
>             (curveto 4.89 -0.84 5.22 -0.55 6.00 -0.80)
>             (curveto 6.78 -1.05 8.03 -1.83 9.00 -1.53)
>             (curveto 9.97 -1.23  10.66 0.15 11.50 0.50)
>             (curveto 12.34  0.85  13.32 0.17 14.00 -0.50)
>             (curveto 14.68 -1.17 15.05 -1.84 16.00 -2.50)
>             (curveto 16.95 -3.16  18.47 -3.82 20.00 -4.49))
>
> { s1*5^\wave_line }
>
> versus
>
> \version "2.22.1"
>
> #(ly:set-option 'debug-skylines)
>
> wave_line = \markup
>    \postscript #"0.3 setlinewidth 1 setlinecap [0 1]
>   0 0 0 setrgbcolor  0.00 -3.50 moveto
>   0.23 -3.71   0.47 -3.93   1.00 -4.00 curveto
>   1.53 -4.07   2.36 -4.00   3.00 -3.50 curveto
>   3.64 -3.00   4.11 -2.07   4.50 -1.46 curveto
>   4.89 -0.84   5.22 -0.55   6.00 -0.80 curveto
>   6.78 -1.05   8.03 -1.83   9.00 -1.53 curveto
>   9.97 -1.23  10.66  0.15  11.50  0.50 curveto
> 12.34  0.85  13.32  0.17  14.00 -0.50 curveto
> 14.68 -1.17  15.05 -1.84  16.00 -2.50 curveto
> 16.95 -3.16  18.47 -3.82  20.00 -4.49 curveto
> stroke "
>
> { s1*5^\wave_line }
>
>
> > Denemo uses postscript to generate a title page with a border.
>
>  From a glance at the output of
>
> git grep "\\\\postscript"
>
> in the Denemo repository, that should be easy to convert
> to \path as above.
>
> Best regards,
> Jean
>
>

Hi,

some thoughts:

A file like the attachment to
http://lists.gnu.org/archive/html/lilypond-user/2013-11/msg00757.html
would be a bit more work to convert, I suppose, although I didn't try ...

ps-code not causing skylines, etc may be a feature in some cases and
not a problem, imho.

Regarding LSR, there are 20 snippets related to postscript. Thus we
can expect \postscript is widely used out there.


Thus, I'd not drop \postscript and friends without a ready-to-use and
user-friendly replacement.
This does not mean I'd object to cairo, my own experiments with the
cairo-backend were all very nice!


Cheers,
  Harm