Thanks Max that works perfectly! But It would still be useful if I could change families inside a MPpage. On Tue, May 31, 2022 at 1:31 AM Max Chernoff wrote:

...

I'm using the following macro to set the font size via h-height:

\starttexdefinition setxheight [#1][#2] \switchtobodyfont[#1, 12pt] \scratchdimen=\dimexpr#2\relax \switchtobodyfont[#1, \cldcontext{tex.dimen.scratchdimen / tex.sp"1ex" * tex.sp"1em" .. "sp"}] \stoptexdefinition

But I can't figure out how to use that in MPpage.

So it looks like the "\cldcontext" command doesn't work quite right inside "textext", and it also looks like "\switchtobodyfont" doesn't take effect until text is actually typeset when we're inside "textext".

This seems to work:

\starttexdefinition setxheight [#1] \switchtobodyfont[\the\dimexpr #1 * \number\dimexpr1em\relax / \number\dimexpr1ex\relax \relax] \stoptexdefinition

\starttext \switchtobodyfont[adventor] \startMPpage draw textext.origin("\setxheight[1cm]Hello!");

draw (0, 1cm) -- (6cm, 1cm); \stopMPpage

\switchtobodyfont[pagella] \startMPpage draw textext.origin("\setxheight[1cm]Hello!");

draw (0, 1cm) -- (6cm, 1cm); \stopMPpage

\switchtobodyfont[heros] \startMPpage draw textext.origin("\setxheight[6pt]Hello!"); draw textext.origin("\setxheight[24pt]Hello!");

draw (0, 6pt) -- (6cm, 6pt); draw (0, 24pt) -- (6cm, 24pt); \stopMPpage \stoptext

The catch here is that you need to set the font family *before* you start the MPpage.

-- Max

Thank you, I'll try that later. On Tue, May 31, 2022 at 9:42 AM Max Chernoff wrote:

...

Thanks Max that works perfectly! But It would still be useful if I could change families inside a MPpage.

Sure, but you'll need to store the x-heights first:

\starttexdefinition storexheight [#1] % Placing the first use of \switchtobodyfont inside a group messes % with the definitions, so we need to reset the font family manually. \edef\oldfontclass{\fontclass}

\switchtobodyfont[#1] \expandafter\newcount\csname #1_xheight\endcsname \global\csname #1_xheight\endcsname=\numexpr 100 * \number\dimexpr1em\relax / \number\dimexpr1ex\relax \relax

\switchtobodyfont[\oldfontclass] \stoptexdefinition

\starttexdefinition setxheight [#1][#2] % Combining these two lines into one sometimes fails. No idea why. \switchtobodyfont[#1] \switchtobodyfont[\the\dimexpr#2 * \csname #1_xheight\endcsname / 100 \relax] \stoptexdefinition

\storexheight[adventor] \storexheight[pagella] \storexheight[heros]

\starttext \startMPpage draw textext.origin("\setxheight[adventor][1cm]Hello!");

draw (0, 1cm) -- (6cm, 1cm); \stopMPpage

\startMPpage draw textext.origin("\setxheight[pagella][1cm]Hello!");

draw (0, 1cm) -- (6cm, 1cm); \stopMPpage

\startMPpage draw textext.origin("\setxheight[heros][6pt]Hello!"); draw textext.origin("\setxheight[heros][24pt]Hello!");

draw (0, 6pt) -- (6cm, 6pt); draw (0, 24pt) -- (6cm, 24pt); \stopMPpage \stoptext

It's pretty ugly code, but it seems to work alright.

-- Max