conf/90082: [syscons] [patch] curses ACS line graphics support for iso15 fonts

[Oliver Fromme]

>Number:         90082
>Category:       conf
>Synopsis:       [syscons] [patch] curses ACS line graphics support for iso15 fonts
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          change-request
>Submitter-Id:   current-users
>Arrival-Date:   Wed Dec 07 18:10:01 GMT 2005
>Closed-Date:
>Last-Modified:
>Originator:     Oliver Fromme
>Release:        FreeBSD 6.0-STABLE i386
>Organization:
secnetix GmbH & Co. KG, Munich, Germany
		http://www.secnetix.de/bsd
>Environment:

	The solution presented in this PR has been developed
	and tested under RELENG_6 (6.0-STABLE), but it is
	believed to apply to all versions from RELENG_4 to
	-current (HEAD).

>Description:

	Most users in western and central Europe use the
	"iso15" syscons fonts.  Those fonts don't contain
	the line drawing characters which are present in
	e.g. the cp437 fonts and are used by various
	console-based "GUI" programs, including sysinstall,
	the famous midnight commander and others.  Instead,
	simple ASCII characters such as "+" and "-" are
	used, which looks ugly.

	In the past years, a lot of users have complained
	about that problem (e.g. on the German BSD mailing
	lists; note that German requires an iso15 font).
	It was often mentioned that Linux does not suffer
	from the same problem.

	The fix below consists of a script that adds the
	missing characters to the existing iso15-8x*.fnt
	font files.  In conjunction with an appropriate
	termcap entry, the problem is solved.

>How-To-Repeat:

	Enable one of the "iso15" fonts (vidcontrol -l) and
	set TERM=cons25l1.  Then run sysinstall,midnight
	commander or any other curses based program that
	uses line drawing characters for window borders or
	similar.

>Fix:

The following script merges line drawing characters from
the cp437 fonts into the iso15 fonts.  The following
files are modified:

   iso15-8x8.fnt
   iso15-8x14.fnt
   iso15-8x16.fnt

The script must be run in a directory containing the
existing font files, i.e. either in

   /usr/share/syscons/fonts

or in the source tree:

   /usr/src/share/syscons/fonts

The new characters are placed in an unused range of the
iso15 fonts, beginning at position 128 (0x80).  All
existing characters are preserved, so the change should
be without any risk.

The "cons25l1" entry in the termcap must be changed
like this (and don't forget to rebuilt termcap.db with
cap_mkdb(1), and logout+login after the change so the
TERMCAP variable in your environment gets updated):

cons25l1|cons25-iso8859-1:\
	:ac=l\200m\201k\202j\203t\204u\205v\206w\207q\210x\211n\212`\213a\214f\260g\261~\267,\215+\216.\217-\220h\221i\2470\222y\223z\224{\225}\243:\
	:tc=cons25w:

Note:  The termcap source directory is /usr/src/share/termcap.

Here's the script to modify the fonts:

#!/bin/sh -

set -e

ACS_START=128
CP437_SRC="218 192 191 217 195 180 193 194 196 179 197
             4 176  27  26  25  24 177 219 243 242 227"

for H in 8 14 16; do

	CP437="cp437-8x$H"
	ISO15="iso15-8x$H"

	DD_ARGS="if=$CP437 of=$ISO15 bs=$H count=1 conv=notrunc"

	uudecode -p $CP437.fnt > $CP437
	uudecode -p $ISO15.fnt > $ISO15

	DST="$ACS_START"

	for SRC in $CP437_SRC; do
		dd $DD_ARGS skip=$SRC seek=$DST 2>/dev/null
		DST=$(( $DST + 1 ))
	done

	uuencode $ISO15 $ISO15 > $ISO15.fnt

	rm $CP437 $ISO15

done

#END.
>Release-Note:
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