Re: \D'R' support

Hi Deri,

On Fri Nov 21, 2025 at 10:38 PM CET, Deri wrote:
> On Friday, 21 November 2025 20:14:31 GMT onf wrote:
> [...]
> > Nice!
> > 
> > However, \D'r' produces rectangles with round edges (like its \D'p'
> > counterpart). Is that what we want? \D'R' is described as drawing a
> > "rule", which I interpret as a filled rectangle with sharp edges. One
> > disadvantage of it being filled is that the lines have a thickness of
> > zero and thus one needs to know the default line thickness (0.04m) to
> > emulate a sharp-edged \D'l 1m 0'. \D'r' does not suffer from this issue
> > as its lines aren't zero width, meaning that \D'r 1m 0' is equivalent to
> > \D'l 1m 0'. But the fact that it has round edges also prevents it from
> > being useful for drawing rules since, as noted above, rules should have
> > sharp edges.
> [...]
> The grops man page hints at the solution to this, the simplest solution is to 
> use:-
>
> \X'ps: exec 0 setlinejoin 0 setlinecap'\c
>
> which works for both grops and gropdf.

I am well aware of the existence of these PostScript/PDF commands.
However, this solution is device-specific. The problem is that there
is no device-independent way to draw a proper rule. I was suggesting
breaking the precedent of unfilled objects having round edges to make
\D'r' work as a proper, simple to use, device-independent rule.

I realize introducing such inconsistency isn't great, but at least there
would finally be a way of drawing a rule without ending up with gaps
(old \l) or round edges (\D'l').

Cheers,
onf