Slurs: too curved, too flat (modyfying Bézier curves)

Hello!

I've been working with this program for some time and I've realised that sometimes the slurs don't look as in the old printed scores.

In short phrases, they look too curved (viz. example 1), whereas in longer phrases, they look too 'flat' (viz. example 2).

[See examples below]

That may cause clashes. In the first case, with the staffs above or below, whereas in the second case, with the notes of the phrase itself. Besides, it doesn't look natural.

So, I've begun modifying them in almost every case. However, it's somewhat tiring, specially when the measure breaking changes, as when one of those modifies slurs is split, it looks weird.

In shorter phrases, I move the points 2 and 3 of the Bézier curve outwards and I lower them (Ex.1)
In longer phrases, I only move them outwards. In both cases, the result looks better.

So, which parameters govern the placing of each point?
Nos. 1 and 4 are the notes you selected, of course, but what about the others?

I think the algorithm should be modified.

I can't program (only a bit of C), but I do know something about Bézier curves, so I would like to help to improve the program.

Thank you!

PS. Anyway, that's the best program ever, Finale and Sibelius will soon go bankrupt!