[NTG-context] VORG and vmtx table in fontloader

22 Jul 2019


      Hello all,

It seems that ConTeXt's fontloader (hence luaotfload's fontloader) 
skips to load the VORG table and topSideBearing in the vmtx table
These informations are used to get the vertical origin of a glyph.
...
readers.vorg = function(f,fontdata,specification)
    reportskippedtable(f,fontdata,"vorg",specification.glyphs)
end
...
readers.vmtx = function(f,fontdata,specification)
...
        for i=0,nofmetrics-1 do
         ... 
            if vheight ~= 0 and vheight ~= vdefault then
                glyph.vheight = vheight
            end
         -- if topsidebearing ~= 0 then
         --     glyph.tsb = topsidebearing
         -- end
I don't know whether vertical metrics are used in ConTeXt.
But, they will be useful for other packages (e.g., LuaTeX-ja)
to improve vertical typesetting.

Regards
Hironori KITAGAWA