How do all the metapost parts fit together.

Wookey wookey at
Mon Sep 8 13:57:34 CEST 2003

+++ Martin Budaj [03-09-08 12:06 +0200]:

>> Michael Lake writes:
>> Actually, thmpost.h file is generated from all metapost sources by the
>> script in the mpost directory. The reason for this is that we
>> had problems to set-up TeX and MetaPost searching paths for macro files
>> indenpendent on used OS and TeX distribution. Now all macros are stored in
>> the therion executable in a form of a string and are written to working
>> directory just before running metapost and tex.

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

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? 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.

>> This'll be no problem then. We want to support also automatical creation of
>> a map legend which would contain only symbols used in particuler map &c.

That's a _really_ good idea - I like that.

>>> >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.

>> You may include symbol re-definition in the layout command (after the
>> undocumented `code metapost' command) in the last development version of
>> therion:
>> layout my
>>   ...
>> # indicates that following lines are metapost code
>>   code metapost
>> # follows an example of an redefinition of a stalactite to empty symbol
>> #
>> # Stalactite is (at present; will be changed soon) internal therion's
>> # name for stalactite point symbol -- look at the first column in
>> # the file (which maps internal names to names used
>> # in the metapost definitions)
>> #
>> # Parameters count and type is fixed; see the original definition
>> # of the stalactite symbol (p_stalactite_UIS) in the file
>>     def Stalactite(expr a,b,c,d) =
>>     enddef;
>>  endlayout

OK - that should do for now.

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.

Aleph One Ltd, Bottisham, CAMBRIDGE, CB5 9BA, UK Tel +44 (0) 1223 811679
work: play:

More information about the Therion mailing list