\definetextbackground[underline] [location=text,alternative=1,background=,frame=off]

for underlining in my documents and

\startuseMPgraphic{mpos:par:columnset}

\iftracepositions show_multi_pars \else draw_multi_pars \fi ;

path p ; p := boundingbox currentpicture ;

currentpicture := currentpicture shifted (0,-StrutDepth/2) ;

setbounds currentpicture to p ;

\stopuseMPgraphic

to control the depth of the underlining.

Unfortunately, this underlining is still sometimes too far beneath the word underlined. I had thought the problem is the -StrutDepth/2. But even if I change it to an absolute value, the underlines to not appear at the same distance even when the word.

Try this test file:

\definetextbackground[underline] [location=text,alternative=1,background=,frame=off]

\startuseMPgraphic{mpos:par:columnset}

\iftracepositions show_multi_pars \else draw_multi_pars \fi ;

path p ; p := boundingbox currentpicture ;

currentpicture := currentpicture shifted (0,-.50) ;

setbounds currentpicture to p ;

\stopuseMPgraphic

\starttext

Donec \startunderline{gravida}\stopunderline{} posuere arcu.

\stoptext

What I need is underlining that occurs at a fixed/constant distance below the words underlined (allowing for descenders, of course, when they are present).

Any suggestions?