[NTG-context] rscale with auto value

Wed Sep 26 17:31:25 CEST 2018

```On Wed, 26 Sep 2018, Pablo Rodriguez wrote:

> Wolfgang,
>
> explaining the following sample to ConTeXt newbies, I have a problem:
>
>    \setuppapersize[A5, landscape]
>    \definefontfamily[mainface][rm][TeX Gyre Pagella]
>    \definefontfamily[mainface][tt][DejaVu Sans Mono][rscale=0.825]
>    \setupbodyfont[mainface, 22pt]
>    \starttext
>    \startmakeup[standard]
>    This is available at {\tt https://contextarden.net}.
>    \stopmakeup
>    \stoptext
>
> The problem is how to explain to someone who never used anything similar
> to ConTeXt or TeX how she has to calculate the scale ratio. It is even
> not simple to myself.
>
> rscale is a useful option, but it would be great to have the auto value
> that does all the math for the user.
>
> Would it be possible that rscale could have the auto value?

See my answer to a similar question on TeX.SE

https://tex.stackexchange.com/a/450658/323