Files with names of the form *.atb are attributes tables, and with names of the form *.ati are attributes subtables. They are used when BRLTTY is displaying screen attributes rather than screen content. Each of the eight braille dots represents one of the eight VGA attribute bits.
Attributes tables can usually be found in the /etc/brltty/Attributes/ directory (see Local Customization for more details). See Attributes Table List for a list of BRLTTY's attributes tables.
An attributes table consists of a sequence of directives, one per line, which define how combinations of VGA attributes are to be represented in braille. UTF-8 character encoding must be used. Whitespace (blanks, tabs) at the beginning of a line, as well as before and/or after any operand of any directive, is ignored. Lines containing only whitespace are ignored. If the first non-whitespace character of a line is # then that line is a comment and is ignored.
dot dot state # comment
Use this directive to specify what a specific dot represents. The default is that all dots are down and not used to represent anything.
What the dot being defined represents. It may be:
The attributes are:
| Name | Hex | binary |
| fg-blue | 01 | 00000001 |
| fg-green | 02 | 00000010 |
| fg-red | 04 | 00000100 |
| fg-bright | 08 | 00001000 |
| bg-blue | 10 | 00010000 |
| bg-green | 20 | 00100000 |
| bg-red | 40 | 01000000 |
| blink | 80 | 10000000 |
Examples:
dot 1 =fg-red dot 2 ~bg-blue
include file # comment
Use this directive to include the content of another file. It is recursive, which means that an included file can itself include yet another file. Care must be taken to ensure that an "include loop" is not created.
| name | description |
|---|---|
| left_right | foreground colour in the left column and background colour in the right column |
| invleft_right | inverse foreground colour in the left column and background colour in the right column |
| upper_lower | foreground colour in the upper square and background colour in the lower square |