color by...

[Olly Betts]

On Tue, Feb 18, 2025 at 10:11:33AM +0000, Wookey wrote:
> On 2025-02-17 14:21 -0500, Richard Knapp wrote:
> > There are two directives I am uncertain if anything uses: REF and TITLE. Could these be used to group survey data?
> 
> They do both have specific purposes and are used by some groups. (we
> use *REF heavily to record where the original survey data for a survey
> is to be found, for example). 
> 
> *title is not used by any software specifically yet SFAIK, but it
>  really should be the name of a section of passage, not an arbitrary
>  colour-grouping set name.

A `*title` in the root survey is used as the title of the .3d file.
Currently other titles are read but not stored, but at some point
they should go in the .3d file attached to their surveys.  Probably
*ref too.  It seems a bad idea to encourage people to abuse directives
for things they aren't intended to be used for.

> However you are right that 'colour by title' or 'colour by ref' would
> allow them to be abused for arbitrary grouping.

In order to support such features we'd need to export them in the .3d
file, but if we're going to do that adding a new directive for whatever
people actually want to set as metadata would make more sense anyway.

A "colour by title", "colour by ref" or "colour by <user metadata>"
needs aven to be able to interpret the data though (or else all it
can really do is arbitrarily assign colours, like the current "colour by
survey" does).  How would that work?  Are you expecting aven to support
"*title green" to mean draw that survey in green?  That has all the
problems that "*colour green" does, with the extra problem that it's
abusing the "*title" directive...

Cheers,
    Olly