[metapost] internal pen question

[Marcel Fabian Krüger]

On Wed, Dec 09, 2020 at 03:38:05PM -0800, Walt Burkhard wrote:
> Hello,
> 
> What size variable is set when using the statement
>                       pickup pencircle scaled 1 ;
> I would like to be able to examine the  current "size" of the pen without
>  actually writing anything.   I am only intending to use this variable when
> I know the pen is a circle too.

`pickup` sets the variables currentpen, pen_lt, pen_rt, pen_top and
pen_bot. If you know that your current pen is a uniformly scaled
pencircle, the easiest way to get the scale factor is probably
(pen_rt-pen_lft).

Marcel