Speeding up and simplifying generation of the manual

[fingolfin]

Building the manual right now takes forever, at least the first time. This is because tons of TikZ graphics are pulled out into separate .tex files which are then compiled individually. Ironically this is done in an attempt to speed up compilation of the manual. Alas, the one-time overhead for starting TeX and parsing all its inputs is quite big and multiplied by the huge number of pictures results in a substantially overhead.

An alternative might be to use the TikZ feature for "externalizing" graphics, see the chapter ""Externalizing Graphics" (right now: chapter 52) in https://ctan.space-pro.be/tex-archive/graphics/pgf/base/doc/pgfmanual.pdf

[fingolfin]

Of course this is not a simple drop-in. I am not sure how to do the above quickly from the top of my head. I'll be happy to discuss some ideas at some point.

But perhaps it would also be an option to simply make the pictures optional so people could run quick tests without all of that...

[fingolfin]

One problem with using the externalize feature is that I am not sure if producing SVGs would work that way...

So here is another idea to at least speed up by the number of cores: right now you generate .tex files for each image, then immediately run tex on each of them right away.

Instead I would suggest to decouple this: first generate all the image *.tex files (and whatever else).

Then use a suitable Makefile rule to run tex in whatever combinations you need on these files. (I can give some hints on how that could work if you are interested in pursuing this idea).

The advantage would be that you could say e.g. make -j8 to tell make to do up to 8 things at once (useful if you have 8 cores). That could then potentially finish the task up to 8 times faster (in reality it also is limited by the performance of your disk drive and other aspects).