Support vertical alignment

[dhardy]

Often for a simple layout it's desirable to centre vertically. Since a Buffer considers the size an input, this library should probably also support top/center/bottom vertical alignment?

#70 affects this slightly; there's still a need to be able to measure height after layout (also #42).

[therocode]

Also hitting the lack of this feature - I was actually a bit surprised, seems like a very basic thing to expect from a text API. Pretty much all text APIs I've worked with before would at least have horizontal align (Left, Center, Right) and vertical align (Top, Center, Bottom).

Does anyone know a good way to approximate, or hack this behaviour?

[bschwind]

@therocode I don't know how useful this is, but I do my own vertical alignment by shaping the text and measuring its height, then offsetting the Y value accordingly:

https:/bschwind/simple-game/blob/12187d4b8df413cb4cae136b43ffd6e870a7488a/src/graphics/text.rs#L618-L637