[therion] Re: How do all the metapost parts fit together.

Michael Lake mikel at speleonics.com.au
Mon Sep 8 13:58:47 CEST 2003

Wookey wrote:

> The main disadvantage of this is that people can't change of add metapost
> definitions without recompiling therion, right? If the definitions were read
> at run-time then we could package UIS or ASF or BCRA or whatever symbols
> separately and install the version you need rather than having a huge
> executable.
> I understand why you've done what you've done, but all of us agree it's a
> horrible hack and I think we should keep it under review if it's really
> sensible. How big are the definitions so far and how big do we expect them
> to get?

The Official UIS list of cave symbols is available from: http://www.karto.ethz.ch/neumann-cgi/cave_symbol.pl

> If they are, and weill remain, quite small and only a tiny number of
> people will want to change them then the current scheme should work OK.

Its a big list but it is quite static. However it does allow countries to maintain the use of some of their own symbols - for instance in Australia we will be retaining a few of the older symbols. Thus cavers will want to have small customised sets. We reallly therefore need to load them at runtime via a library or a package like LaTeX does. Probably as plain text mpost macros in a file that is called up by the thconfig file.

Mike pondered.....

>>> The reason why I am trying t fit it together is so I can do things like make my own symbols -- well even help you make the many other UIS symbols that arent in therion yet too. I dont know much metapost but can learn. It appears at present that to add new symbols one must add the mp code and then recompile.

>> It's possible to add/change metapost symbols without new therion compilation. The interface is rather experimental but should work.
> ah, I should have read this first.

but it was undocumented. :-) I will try and help with documentation.

> Welcome aboard Michael, BTW - the more hands the merrier I think. Therion is
> the way forward but it still needs plenty of work to make it accessible to
> the less geeky cave surveyor.

I can help with documentation. I am good at LaTeX, I am making some headway with plain TeX (even have Knuths book) and I might have to learn C++ :-)

Mike Lake
Caver, Linux enthusiast and interested in anything technical.

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