Re: extended ASCII characters do not show up

[Thomas Dickey]

On Sat, 1 Oct 2005, amores perros wrote:

> > The ACS_xxx symbols are a character (which corresponds to the vt100 
> > line-drawing), with A_ALTCHARSET added.  ncurses keeps track of the 
> > A_ALTCHARSET, and when it is time to write the data to the screen, checks 
> > to see if the encoding is UTF-8.  If so, it checks some special cases (such 
> > as Linux console) to see if it should not try to use the terminfo string to 
> > transform its internal character to the terminal's equivalent.
>
> Its a little tough to follow looking at ncurses sources, as I think
> these .in files will expand after some autotools, but
> A_ALTCHARSET probably expands to  NCURSES_BITS(@cf_cv_1UL@,14),
> and NCURSES_BITS probably expands via
>
> #define NCURSES_BITS(mask,shift) ((mask) << ((shift) + NCURSES_ATTR_SHIFT))
>
> so I think A_ALTCHARSET sets at least 14 bits up (and WA_ALTCHARSET
> is the same thing as A_ALTCHARSET).

close: A_ALTCHARSET is a mask containing 1 bit, shifted up left bits.

In libncurses, the A_CHARTEXT mask corresponds to the bits in a chtype 
that are used to store an 8-bit character.  In libncursesw that mask is 
not used much, since the character data is ultimately stored in the 
.chars[] array of cchar_t rather than in the chtype data.

> I don't know what a "terminfo acsc string" is, but I think I'm
> content with the level of my limited understanding now, and
> thanks for pointing out where the table is, to see what unicode
> characters are being used for drawing.

no problem

--
Thomas E. Dickey
http://invisible-island.net
ftp://invisible-island.net