[Therion] Minimum symbol scale

[Tarquin Wilton-Jones]

> I know that I suggested one format below, but thinking about it more,
> this might be better:
> min-symbol-scale <scale> [<point/line/area/group/special> <symbol-type>]
> 
> That means no fussing around with the parameter ordering. But it is then
> inconsistent with symbol-colour.

I have run into this one again, and really need this functionality.

Andrew (or perhaps this is Bruce's originally) has a partial solution in
MetaPost:
if abs(llcorner txt - ulcorner txt ) > 3pt:
The trouble with this is that it only works if the text is all on one
line. It breaks with this because it sees the outer dimensions as huge:
point label -text [foo<br>bar>]

The text has already been converted into a "picture" by the use of the
"btex" operator. I tried using the "textpart" operator to get back to
the original (so I could use a substring operator to look for the
\thlabel\thlargesize substring), but that didn't work, unfortunately.

Any other thoughts about how to analyse it? Obviously I could construct
my own btex picture objects and compare the sizes to see if it perfectly
matches a known size, but that gets confused by "L" and "g" being
different sizes due to "g" descending below the line, so it would be
prone to errors, and would need a lot of tests with different text.

There has to be a MetaPost solution in here somewhere...