Drawing vertical text glyphs

[Caolán McNamara]

On Mon, 2021-04-26 at 12:30 +0200, Luboš Luňák wrote:
>  CairoTextRender::DrawTextLayout()

I've no great insight here, but the cairo one's purpose was to replace
the older X11 text renderer and tried to match what that one did. I
added qadevOOo/testdocs/vertical-testcase.odt at the time to test
before/after for that cairo vertical text rendering vs its predecessor.