exact placement rules for volta brackets?

[Marc Hohl]

Hello all,

I am just about rewriting the bar line user interface and stumbled across a
serious problem: with my new approach, the valta brackets are displaced.

For developing a fix, I need to know how this is properly done.
Gould doesn't say much about the details, and this is the only reference 
I have.

For the moment, the center of the volta hook is placed over the left
edge of the thick bar line, see the attached picture.
This looks a bit weird, I think.

Any hints/references/improvements?

Thanks in advvance,

Marc

volta.jpg
Description: JPEG image