Re: [Groff] Underlining in groff

[Werner LEMBERG]

> I think this is the solution to go, and I'll implement it if I have
> time: Use an ms-like underlining macro if either .ce or .rj is
> active.

Please try the attached version: .ce and .rj should now work as
expected.


    Werner

.\" ul.tmac
.\"
.\" Copyright (C) 2003, 2004, 2009 Free Software Foundation, Inc.
.\"
.\"   written by Werner LEMBERG <address@hidden>
.\"
.\" ul.tmac is free software; you can redistribute it and/or modify it under
.\" the terms of the GNU General Public License as published by the Free
.\" Software Foundation; either version 2, or (at your option) any later
.\" version.
.\"
.\" ul.tmac is distributed in the hope that it will be useful, but WITHOUT ANY
.\" WARRANTY; without even the implied warranty of MERCHANTABILITY or
.\" FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
.\" for more details.
.\"
.\" You should have received a copy of the GNU General Public License along
.\" with ul.tmac; see the file COPYING.  If not, write to the Free Software
.\" Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
.\"
.\" History:
.\"
.\"   Version 1.0  2003-Dec-18
.\"     First release.
.\"
.\"   Version 1.1  2004-Jan-14
.\"     Improve documentation.
.\"
.\"   Version 1.2  2004-Jun-09
.\"     Add GPL.
.\"
.\"   Version 1.3  2009-Jul-31
.\"     Make underlining work with .ce and .rj requests.
.\"
.\"
.\" This file defines a macro `.Underline' which underlines its arguments
.\" continuously.  It is completely transparent to justifying, this is,
.\" the text to be underlined (and the text surrounding it) is typeset
.\" identical to normal text, without any distortion in filling.
.\"
.\" Note that you can use `.Underline' in diversions; it works also across
.\" page breaks and is robust against vertical position traps.
.\"
.\" With the -me package it might happen that you get a warning (and no
.\" underlining) if the text to be underlined is in the last line of the
.\" document:
.\"
.\"   Line  -- Unclosed block, footnote, or other diversion (ul-div)
.\"
.\" Simply add a final `.br' to your document to get correct behaviour.
.
.
.\" The vertical position and thickness of the underline segments can
.\" be controlled with the following two strings.
.
.ds Underline-thickness (\En[.ps]s / 15u)
.ds Underline-offset (\En[.ps]s / 5u)
.
.
.if n \{\
.  de Underline
.    cu
\\$*
.  .
.
.  nx
.\}
.
.
.eo
.
.
.de \"
..
.
.
.de Underline
.  \" The .ce and .rj requests must be handled specially since neither of
.  \" them sets \n[.k].
.  if \n[.ce] \{\
.    ul-simple \$*
.    return
.  \}
.
.  if \n[.rj] \{\
.    ul-simple \$*
.    return
.  \}
.
.  \" If we aren't in our `ul-div' diversion, start it now, reset the
.  \" .Underline and diversion line counters, and set the diversion trap.
.  \" Otherwise just increase the .Underline counter.
.  ie '\n[.z]'ul-div' \
.    nr ul-count +1
.  el \{\
.    di ul-div
.    dt 1u ul-do
.    nr ul-count 0
.    nr ul-line 0
.  \}
.
.  nr ul-active 1
.
.  \" Embed code to set various registers before and after the text.
.  \" This code is evaluated when the diversion is reread the first time.
.  \"
.  \" Saving \n[.k] as horizontal positions is sufficient since the
.  \" indentation is set to zero while rereading.  On the other hand, we
.  \" need the (normal) indentation and line length values while filling
.  \" the diversion, to get the start and end positions of normal lines in
.  \" case an underline segment is broken across lines.
\?\
\R'ul-.i-\n[ul-count] \n[.i]'\
\R'ul-.l-\n[ul-count] \n[.l]'\
\R'ul-.ll-\n[ul-count] \n[.ll]'\
\R'ul-start-pos-\n[ul-count] \En[.k]'\
\?\
\$*\
\?\
\R'ul-end-pos-\n[ul-count] \En[.k]'\
\?
.
.  nr ul-active 0
..
.
.
.de ul-simple
\Z'\
\D't \*[Underline-thickness]''\c
\Z'\$*'\
\v'\*[Underline-offset]'\
\D'l \w'\$*'u 0'\
\v'-\*[Underline-offset]'
..
.
.
.de ul-do
.  \" Switch to another environment to preserve the partially filled line.
.  ev ul-env
.  evc 0
.
.  \" Emit vertical space possibly truncated by the diversion trap.
.  if \n[.trunc] \
.    sp \n[.trunc]u
.
.  \" Save the .Underline and `active' counters as array elements, indexed
.  \" by the diversion line counter.
.  nr ul-count-\n[ul-line] \n[ul-count]
.  nr ul-active-\n[ul-line] \n[ul-active]
.
.  \" End diversion if there isn't a broken underline segment.  Otherwise,
.  \" move trap down to handle next line.
.  ie !\n[ul-active] \{\
.    dt
.    di
.
.    \" Prepare diversion handling.
.    in 0
.    nf
.
.    \" Copy the diversion to set the embedded number registers.
.    di ul-div1
.    ul-div
.    di
.    rn ul-div1 ul-div
.
.    \" Process diversion again.  The trick is to insert underline
.    \" segments *before* the corresponding text line is emitted.
.    nr ul-max-line \n[ul-line]
.    nr ul-count 0
.    nr ul-line 0
.
.    di ul-div1
.    \" Call .ul-do1 manually the first time.
.    ul-do1
.    ul-div
.    di
.
.    \" Finally emit underlined text.
.    ul-div1
.  \}
.  el \
.    dt (\n[.d]u + 1u) ul-do
.
.  nr ul-line +1
.
.  \" Restore previous environment.
.  ev
..
.
.
.de ul-do1
.  if (\n[ul-line] <= \n[ul-max-line]) \{\
.    nr ul-last \n[ul-count]
.
.    \" Get saved counters from the array.
.    nr ul-count \n[ul-count-\n[ul-line]]
.    nr ul-active \n[ul-active-\n[ul-line]]
.
.    \" Set line thickness.
\Z'\
\D't \*[Underline-thickness]''\c
.
.    \" A typical diversion to be handled looks like this:
.    \"
.    \"    xxxx -0--- xxxx -1----- xxxxxxxx -2--
.    \"    -2------- xxxxxx xxxxx -3----- xxxxxx
.
.    while (\n[ul-last] < \n[ul-count]) \{\
\Z'\
\h'\n[ul-start-pos-\n[ul-last]]u'\
\v'\*[Underline-offset]'\
\D'l (\n[ul-end-pos-\n[ul-last]]u - \n[ul-start-pos-\n[ul-last]]u) 0'\
\v'-\*[Underline-offset]''\c
.      nr ul-last +1
.    \}
.
.    ie \n[ul-active] \{\
.      \" An underline segment broken across lines.
\Z'\
\h'\n[ul-start-pos-\n[ul-count]]u'\
\v'\*[Underline-offset]'\
\D'l (\n[ul-.ll-\n[ul-count]]u - \n[ul-start-pos-\n[ul-count]]u) 0'\
\v'-\*[Underline-offset]''\c
.
.      \" Set start position to the indentation value of next line.
.      nr ul-start-pos-\n[ul-count] \n[ul-.i-\n[ul-count]]
.      \" Update length of next line.
.      nr ul-.ll-\n[ul-count] \n[ul-.l-\n[ul-count]]
.    \}
.    el \{\
.      \" The last underline segment in the diversion.
\Z'\
\h'\n[ul-start-pos-\n[ul-count]]u'\
\v'\*[Underline-offset]'\
\D'l (\n[ul-end-pos-\n[ul-count]]u - \n[ul-start-pos-\n[ul-count]]u) 0'\
\v'\*[Underline-offset]''\c
.    \}
.  \}
.
.  \" Move trap down to handle next line or remove trap.
.  ie \n[ul-active] \
.    dt (\n[.d]u + 1u) ul-do1
.  el \
.    dt
.
.  nr ul-line +1
..
.
.ec
.
.\" EOF