[Therion] Scaling text and text orientation

[Wookey]

On 2007-11-19 21:38 -0000, Cooper, Ben wrote:
> The problem is that as the text size scales, it overlays cave passage.
> So a scrap has to be drawn with the scale in mind.  In that case, the
> offset needs to scale with the text size.  A simple solution would be
> for the text of a point label to be left or right justified, so it can
> be positioned close to the relevant feature, and the text will then
> scale harmlessly to the right or left.  This doesn't solve the problem
> of the text overlaying other adjacent scraps or cave passages, of
> course.  

I've had real troubles with this too. You can label an individual
scrap OK, but then some other scrap will come and make your lables
look crap by half-overlaying some. In a complex multi-layer cave with
different output sizes this is a real problem. It is incredibly
inefficient opening a scrap file to edit one label position a tiny bit
to the right then regenerating the whole thing and loading the PDF
again to see if it is in thte right place yet. 

Of courtse the solution to this is very difficult, but some kind of
algorithm to place labels on the final map, not just the one scrap
might get close to doing the right thing. Julian Todd suggested a(n
invisble) line along which the label could move outwards until it
found it was not overlapping anything. With some kind of limit when it
simply decides the label 'doesn't fit' and should just be left off.

This is a really hard problem, but currently Therion doesn't even try
to solve it, and doing it manually is very tedious. There is
definately room for improvement, although Therion's design makes it
difficult.

I like the metpost for large-area label-selectivity. That could be
really useful. I just got a much faster computer going today so may
try some of the mulu stuff again (I pretty-much gave up as the
rendering was so slow).

Wookey
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