On Tue, Sep 24, 2013 at 7:45 PM, Lars Huttar <lars_huttar@sil.org> wrote:

> On 9/24/2013 12:01 PM, Lars Huttar wrote:
> >
> > Can you explain how/why the two ways of increasing the font size should
> > have such different effects? (I have read section 5.8 and 5.9 about
> > selecting bodyfonts and interlinespace but still don't get it.)
> > \tfc is described as a "font selector" command (5.3.2). It seems to me
> > that both \tfc and \switchtobodyfont[20pt] simply attempt to switch to a
> > different size of whatever bodyfont is currently in effect. But there
> > must be something I'm missing. (Or else it's just an arbitrary
> > distinction, but that seems unlikely.)
> >
> >
>
> Is it that \switchdobodyfont changes the *body* font, which engages the
> associated bodyfont environment...
> whereas \tfc changes the *font*, not the *body* font?
>
> Lars
>
> You can look into
 font-pre.mkiv
\tfc augment the fontsize of a factor of 1.728
It's relative to the default fount size not to the current fontsize:
{\tfc foo {\tfc foo}} both foo have the same size
<http://contextgarden.net>

But interlinespace is not modified, so we need to reset
\starttext
OK: \input knuth\blank{\tfx WRONG: \input knuth\blank \tfc WRONG: \input
knuth\relax} \page
OK: \input knuth\blank{\tfx\setupinterlinespace OK: \input knuth\blank \tfc
WRONG: \input knuth\blank} \page
OK: \input knuth\blank{\tfx\setupinterlinespace OK: \input knuth\blank
\tfc\setupinterlinespace OK: \input knuth\blank}
\stoptext


--
luigi