Drawing vertical text glyphs

[Luboš Luňák]

 Hello,

 is here somebody who understands drawing vertical (asian etc.) texts? I need 
help in that area for the Skia backend.

 Specifically, the problems are tdf#137907, tdf#136081 and tdf#105650, which 
all stem from the same problem of positioning vertical glyphs. 
Positioning "normal" horizontal glyphs works fine, even in rotated text. I've 
looked at other VCL backends, and most of them handle vertical glyphs 
specially[*], and each of them in a different way. And the visual results are 
also different for those that I can check, and even that is different from 
what I can see if I check e.g. tdf#103785 in MS Office.

 Given that I don't have that deep understanding of font rendering and I'm 
also not familiar with languages that need vertical glyphs, I have no idea 
what the correct way to do this should be. Is there somebody who understands 
this and could help me (preferably with knowledge of how it works, but even 
just being able to visually tell what's correct could do).

[*] AquaSalGraphics::DrawTextLayout(), CairoTextRender::DrawTextLayout(), 
PrinterGfx::DrawGlyph(), ExTextOutRenderer::operator() , make your pick

-- 
 Luboš Luňák
 l.lunak at collabora.com