Re: Units for "set margin"?

[Philipp K. J. <ja...@ie...>]

Interesting. Thanks.

On Thursday 24 July 2008 13:25, you wrote:
> On Thursday 24 July 2008 12:57:42 Philipp K. Janert wrote:
> > According to the manual, the units for the
> > 	set ?margin
> > commands are "character heights or widths,
> > as appropriate", using the default font for the
> > current terminal, I assume.
> >
> > What does this mean for non-fixed character
> > sized fonts, including Helvetica?
>
> Internally, it means the values for width and height stored in the
> current terminal's term->h_char and term->v_char.
> Each terminal driver is supposed to make a best-effort attempt to
> store reasonable numbers for these values, but the accuracy varies.
>
> In the specific case of PostScript, the vertical size is set to the normal
> font size in points.  (E.g. for "Helvetica,12" the height is 12 points).
> The horizontal size is set to 0.6 of the vertical size.
>
> The libgd-based terminals do not assume that the nominal font size
> is correct.  Instead they query the actual dimensions of a test string
> and set term->h_char and term->v_char on the empirically determined
> values.
>
> The accuracy of the values can be judges by inspecting the output
> of the "test" command.  If the values are accurate, then the box around
> the central test string will fit nicely.  If the values are garbage, the
> box will be too big or too small or improperly proportioned.