Re: Why does -dbackend=svg -dcrop remove system-system-spacing?

[Aaron Hill]

On 2021-01-08 3:01 pm, David Wright wrote:
> To answer your question—why not use the -dcrop option—I think
> we are in agreement that:
>
> $ lilypond-2.21.80-1.linux-64/bin/lilypond --svg -dcrop Bača.ly
>
> will produce the tightly packed:
>
> E   ┌──────────────┐
>     │▒▒▒▒▒▒▒▒▒▒▒▒▒▒│
>     │▒▒▒▒▒▒▒▒▒▒▒▒▒▒│
>     │▒▒▒▒▒▒▒▒▒▒▒▒▒▒│
>     └──────────────┘
>
> which is what you implied you didn't want (by saying "Is this
> supposed to happen?" and "Seems like cropping should be …").

This is clearly something that needs to be documented more clearly, but 
also we may need to reconsider what -dcrop *should* be doing rather than 
what is currently does.

It seems reasonable for folks to expect -dcrop to simply remove the 
empty margin space, which is why there is confusion that inter-system 
spacing is affected.  What -dcrop seems to actually do is reduce each 
system to its reported extents, packing the results together while 
ignoring the paper spacing variables.  Is this a bug or not, is an 
unanswered question.  The documentation makes no comment about reduced 
spacing, only that margins are to be ignored.

At this time, if you just want to remove the outer margins, then you 
should not be using -dcrop.  Rather, you should be manually removing the 
margins themselves within the \paper section.  Basically, make the 
virtual paper match precisely what you need, obviating the need to use 
-dcrop.


-- Aaron Hill