[Therion] Slope symbol needed

Wookey wookey at aleph1.co.uk
Thu May 4 19:55:46 CEST 2006

+++ Philip Schuchardt [06-05-04 09:16 -0400]:
> This is my overloaded symbol for gradient point.  I want to make a line symbol 
> for gradient but I havent gotten around to it. 
> code metapost
>     def p_gradient_AMER (expr pos,theta,sc,al) =

snip. OK, thanx a lot for that. Now I just need to know what to do with it
in order to use it:

I have an example of overriding a symbol in a thconfig file
# bodge to make floor-steps look sensible
 code metapost
  let l_floorstep = l_border_visible_SKBB;
This goes inside the layout/endlayout.  

so we want something like
 code metapost
 let p_slope = p_gradient_AMER;

What I don't know is where we put the files (or how to find out the symbol
names we want to override). There should be a load of symbol files, but they
seem to be compiled into the therion excutable. And there needs to be some
way for users to find out symbol names. (I looked in mpost dir in source and
grepped, but that is not suitable for users that want to change a symbol).

It looks like we need to add the snippet provided to the symbols in
mpost/thPoint.mp file and then rebuild therion.

Guys - how do we add new symbols like this? If the answer is 'rebuild
therion from source' then something is wrong in the design...
Maybe an extrernal path is checked as well as the internal library?

It must be possible to have an external symbols library. I know you built
everything in to avoid people having problems with paths, but it is a
horrible hack. At least for the debian version I would really like to move
the metpost and tex stuff back into the places it should be, then I hope
adding new symbols would be something that could be by users. 

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