[Devel] extra metric points

[George Williams]

I was reading though some notes from Apple on the 'gvar' table and these
notes mentioned that there were four extra metrics points added in
addition to the points that describe the contours.

Before this I was only aware of points for left and right side-bearings.
I presume the other two are top and bottom side-bearings. I can't find
any documentation about this on the Apple site (everything I've found
there aside from these notes mentions 2 metrics points not 4). I've
asked for clarification, but that often takes time...

Does anyone on this list know if Apple added an extra two metrics points
and what they mean?

It makes sense that there should be top and bottom side-bearings in
fonts with vertical metrics, but the example given was for a latin font.