Nice to see my work is not completely unnoticed, but, you are right to take it with a grain of salt as I don't actively maintain any of the stuff I linked! The

Nice to see my work is not completely unnoticed, but, you are right to take it with a grain of salt as I don't actively maintain any of the stuff I linked! The paper I previously linked discusses the problem of "solution selection" as you state: the problem of selecting from systems with multiple solutions (for example, when one specific side of a triangle is constrained onto another line, it can do so in one of two directions or "orientations" as the paper refers to them). The paper presents two strategies for selecting solutions: a selection heuristic approach, whereby the user defines that they want a certain class of cluster such as one with clockwise angles; and a prototype-based selection method where the solution which most closely resembles the user's sketch is selected. I prefer the latter approach, but that's unfortunately the one that is buggy in the library I found. I completely agree about how awesome it would be to have a parametric drawing library. That's actually what my overall goal was to be, eventually, once I got the optical layout problem solved - there's nothing really to stop such a library from being generalised to any kind of drawing. I was surprised that I couldn't find one already, to be honest, as it would no doubt be really useful in untold applications. If you manage to get something working, please let me know :-)