The fundamental issue is the small repertoire of fillable,
colourable or shadeable objects in pic -- basically box, circle,
if you want to play with, please go ahead! However, I fear that this
is a non-trivial task, as Ted has explained (especially if you read
the thread he mentioned in his previous post).
One idea which came to me in the course of that was that it
would be useful to be able to assign a "closed" attribute to
an object drawn by pic, [...]
[ arc down rad 1; arc rad 1;
line up 0.5 left 0.75;
line left 0.5;
line left 0.75 down 0.5 ] closed shaded "green"
This is a nice idea, indeed.
However, inmplementing this sort of thing would involve modifying
pic extensively at a deep level.
I don't think that this would be extremely hard, given the natural
modular structure of gpic's C++ code. A few hundred lines of code I
estimate, if at all.
I have, indeed, a somewhat intermittent project in hand to implement
a fairly general repertoire of such things for pic. [...]
Sounds very interesting!