[BRLTTY] Working with braille characters in console mode?

[Samuel Thibault]

Mario Lang, le Sun 20 Jan 2008 22:58:08 +0100, a écrit :
> Samuel Thibault <samuel.thibault at ens-lyon.org> writes:
> > Samuel Thibault, le Sat 19 Jan 2008 21:13:46 +0000, a écrit :
> >> > have brltty map them correctly to the associated dot combination?
> >> 
> >> Unfortunately the screen driver model still does't take unicode into
> >> account and thus brltty will still show question marks for now.
> >
> > Maybe we could extend it temporarily without having to revamp everything
> > right now by just adding a SCR_DOTS request that returns dots, if any?
> > For 0x28uv, the screen driver would return ' ' for SCR_TEXT and 0xuv for
> > SCR_DOTS, which the main loop of brltty.c could mix just before the call
> > to writeWindow.
> 
> Could you elaborate a litte bit on this?  As far as I see,
> the vcsa device only uses a 16 bit value for each character on the
> screen to mix attribute and character values.  How does an application
> actually see the character at a certain position is unicode 0x2800?
> Or did I miss something here?

A VGA font can be 256 or 512 characters. In the fonts I provide on
brl.thefreecat.org, the 256 first characters are as usual, while the 256
others are U+28uv, which brltty is already able to detect by reading the
Screen Font Map from the kernel.

Samuel