Curses , Graphic Characters

[Andy Behrens]

In article <41104 at jplgodo.UUCP> deutsch at jplgodo.UUCP (Michael Deutsch) writes:
> 
> I am trying to use standard graphic characters available
> on many terminals including WYSE 50, 60, etc.
> 
> These characters on a typical UNIX System V, Rel 3.2 are
> located in /usr/include/curses.h and are referred by names of:
> 
> ACS_VLINE	-	Vertical (border) graphic character
> ACS_HLINE	-	Horizontal (border) graphic character
> 
> These are not available, as far as I can tell, in XENIX include
> files.

Neither of the two methods that you listed for describing graphics
(line-drawing) characters is standard.   The GXXX labels would be a
reasonable way of doing it, but standard termcap entries have two-
character labels.

The solution I'd suggest is to use the acsc (:ac) attribute.  This is
defined in terminfo on Sun's machines, and I believe I've seen it on
some SysV machines also.  Sun mentions it in their termcap(5) man page,
even though they haven't put any :ac entries in /etc/termcap.

Here's an edited description from Sun's terminfo(5) man page.

+---
|  Attribute name         Terminfo Termcap
|  --------------------------------------------------------------------
|  enter_alt_charset_mode   smacs    as   Start alternate character set
|  exit_alt_charset_mode    rmacs    ae   End alternate character set
|  acs_chars                acsc     ac   Graphic charset pairs aAbBcC
|
|  If the terminal has a line drawing alternate character  set,
|  the  mapping  of  glyph to character would be given in acsc.
|  The definition of this string  is  based  on  the  alternate
|  character  set  used  in  the  DEC  VT100 terminal, extended
|  slightly with some characters from the AT&T 4410v1 terminal.
|
|	 glyph name                 VT100+
|				   character
|
|	 arrow pointing right          +
|	 arrow pointing left           ,
|	 arrow pointing down           .
|	 solid square block            0
|	 lantern symbol                I
|	 arrow pointing up             -
|	 diamond                       `
|	 checker board (stipple)       a
|	 degree symbol                 f
|	 plus/minus                    g
|	 board of squares              h
|	 lower right corner            j
|	 upper right corner            k
|	 upper left corner             l
|	 lower left corner             m
|	 plus                          n
|	 scan line 1                   o
|	 horizontal line               q
|	 scan line 9                   s
|	 left tee                      t
|	 right tee                     u
|	 bottom tee                    v
|	 top tee                       w
|	 vertical line                 x
|	 bullet                        ~
|
|  The best way to describe a new terminal's line graphics  set
|  is to add a third column to the above table with the charac-
|  ters for the new terminal that produce the appropriate glyph
|  when  the  terminal  is in the alternate character set mode.
|  For example,
|
|	 glyph name           VT100+   new tty
|			       char     char
|
|	 upper left corner      l         R
|	 lower left corner      m         F
|	 upper right corner     k         T
|	 lower right corner     j         G
|	 horizontal line        q         ,
|	 vertical line          x         .
|
|  Now  write  down  the  characters  left  to  right,  as   in
|
|	 acsc=lRmFkTjGq\,x.
|
|  [This would be :ac=lRmFkTjGq\,x.: in a termcap entry].
+---

Here are some sample entries to get you started.  Attributes "as" and
"ae" are used to shift into and out of graphics mode.  The "other"
entry is for a terminal without line-drawing characters.  It uses -, |,
and + instead.

    vt100|vt320
	:as=\E(0:ae=\E(B:ac=jjkkllmmnnqqttuuvvwwxx:

    altos2|Altos II
	:as=\E(0:ae=\E(B:ac=jYk?lZm at nEqDtCu4vAwBx3:

    altos3|Altos III
	:as=\E(0:ae=\E(B:ac=jKkLlMmNnOqJtUuVvWwXxY:

    wyse925|Wyse-50 emulating tvi925
	:as=\EH^B:ae=\EH^C:ac=j5k3l2m1n8q\072t4u9v=w0x6:

    esprit925|Esprit-6310 emulating tvi925
	:as=\E$:ae=\E%:ac=jHkGlFmEnIqKtMuLvOwNxJ:

    other
	:as=:ae=:ac=j+k+l+m+n+q-t+u+v+w+x|:


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