Spending a bit of time around the SFML text rendering recently, I have noticed that it's locked in to a horizontal direction.
After checking, it looks like
FreeType does provide a 2-dimensional (vector) advance but
SFML only uses the x component - even in Font/Glyph i.e. it's not just Text ignoring it, it's not available from Font so even a custom text renderer would not be able to use it. This makes Font useless for any non-horizontal direction text renderer.
My suggestion is - at least at first - expose the 2D advance in Font/Glyph allowing separate renderers to use all of the font.(by simply changing advance to Vector2f instead of float)
Following that, Text could be expanded to also be able to handle it properly. This isn't required but is an option. However, exposing the 2D advance is required before that can even be considered. Of course, exposing it means that Text would need to adjusted to focus on just the one component but it's (obviously) as simple as making a reference, for example. Later, the 2D vector could be used, likely without much disruption to the legibility of the code.
e.g.
position += advance (both floats representing xs)
position += advance (both representing Vector2fs)
