Re: [Groff] offset scaling with .bd

[Ralph Corderoy]

Hi Dan,

> The original troff reference manual mumbles something like:
> 
>  .bd F N  "The characters in font F will be artificially
>             emboldened by printing each one twice, separated by N-1
>             basic units. A reasonable value for N is 3 when the charater
>             size is in the vicinity of 10 points..."

And in the front reference pages lists it as `.bd S F N', which is
wrong.

> However, unless I use values for N of the order of a few hundreds
> (e.g.  600) the emboldening is negligible.  The gnu groff manual
> mentions something about .bd that I don't understand if has any
> relevance to this problem. Perhaps someone can educate me on how the
> scaling of the offset in the .bd command works.

As Kernighan says, N's default unit is the `basic unit' as opposed to
inches, points, etc.  The size of a basic unit differs between output
devices.  There's 72000 basic units to the inch when talking about
grops, so 3 won't go very far.  Presumably, 3 was sufficient for
Kernighan's environment.

You can specify a unit, e.g. `.bd R 1p', so it's independent of the
output device.  Or use something that returns a basic unit, e.g. `.bd R
\w'x''.

If I haven't made this clear, I've never used it, ask again and someone
on the list will put me right.

Cheers,


Ralph.