Re: Cairo: Please test mingw installer

[Michael Käppler]

Hi Knut,
thank you very much for your work!

Am 29.07.2021 um 01:13 schrieb Knut Petersen:
> Here are installers for lilypond with the  cairo backend after a
> significant remix by Han-Wen. GUB has been changed to use a cairo
> version that fixes three bugs relevant for lilypond, a test would be
> nice.
Here the test results that I could acquire so far.
At first I tested the mingw installer under Windows 10.

The first problem I noticed with a bigger score was that Lilypond failed
with
"schwerer Fehler: Cairo context status 'invalid tag name, attributes, or
nesting'"

This happens only if point-and-click is enabled. Otherwise it compiles fine.
Under linux-64, with the same input file, this error does not occur.
Other files also work fine under both architectures.
Unfortunately I do not have time to cook a minimal failing example.

The following observations are tied to the mingw installer.

A small nit: SVG files are the only ones having no additional 'cairo'
file extension. Is this intended?

All output formats compiled fine otherwise and look ok at a first glance.
The cairo pdf file is twice as large as the 'normal' one:

$ ls -l partitur*.pdf
-rw-r--r-- 1 Michael 197121 1586286 Jul 29 10:16 partitur.cairo.pdf
-rw-r--r-- 1 Michael 197121  721407 Jul 29 10:17 partitur.pdf

I made a visual diff of both PDFs. You can download it here:
https://drive.google.com/file/d/1NiPODfHVWjawKXjF2t-wveWE-BjMj0Yc/view?usp=sharing

The 'classic' PDF is green, the cairo PDF is red. If they match exactly
it merges to black.
I could not spot big differences, there is a bunch of very small, subtle
differences, however.

Some timings:
$ time /d/Lilypond-generic/2.23.4/usr/bin/lilypond -dpoint-and-click=#f
partitur.ly

real    0m35.632s
user    0m0.000s
sys     0m0.078s

$ time /d/Lilypond-generic/2.23.4/usr/bin/lilypond -dpoint-and-click=#f
-dbackend=cairo partitur.ly

real    0m33.175s
user    0m0.015s
sys     0m0.046s

$ time /d/Lilypond-generic/2.23.4/usr/bin/lilypond --ps partitur.ly

real    0m33.462s
user    0m0.031s
sys     0m0.062s

$ time /d/Lilypond-generic/2.23.4/usr/bin/lilypond --ps -dbackend=cairo
partitur.ly

real    0m39.974s
user    0m0.015s
sys     0m0.062s

$ time /d/Lilypond-generic/2.23.4/usr/bin/lilypond --png partitur.ly

real    0m51.850s
user    0m0.000s
sys     0m0.062s

$ time /d/Lilypond-generic/2.23.4/usr/bin/lilypond --png -dbackend=cairo
partitur.ly

real    0m47.377s
user    0m0.015s
sys     0m0.062s

$ time /d/Lilypond-generic/2.23.4/usr/bin/lilypond --svg partitur.ly

real    1m53.029s
user    0m0.015s
sys     0m0.093s

$ time /d/Lilypond-generic/2.23.4/usr/bin/lilypond -dbackend=cairo --svg
partitur.ly

real    1m39.438s
user    0m0.015s
sys     0m0.046s

Michael