README.gray

This copy of the nethack source includes a patch to allow black objects
(orcish daggers, ravens, pits, etc.) to be represented using a dark shade
of gray on some terminals.  Normally, nethack shows them as blue to avoid
printing unreadable black-on-black text, but this confuses them with with
objects that are actually blue (cornuthaums, sapphires, soldier ants,
etc.).

The patch works by specifying "black foreground" and "boldface" at the
same time.  On terminals that simulate bold with brighter colors, this
produces a distinct color.  Terminal emulators based on PC CGA/EGA/VGA
textmode generally have this property.

However, on terminals that implement actual bolding -- thickening the
font without changing the color, it will result in invisible text.  So,
the feature is not enabled by default.  It must be activated with the new
option "use_darkgray".

Notes:
 * This patch is only effective in when TERMINFO is defined in unixconf.h

 * Highlights added by the existing "use_inverse" and/or "hilite_pet"
options will probably not be visible when applied to black objects.

 * nethack doesn't properly follow the rules for using the tputs()
function of termcap/curses.  The first argument is supposed to be a string
obtained from the termcap/terminfo functions.  Nethack assumes it can
provide a null pointer to do nothing, and can string-concatenate two codes
(boldface and a color select) and use them as one.
   My code does not fix this -- although it uses "" instead of a null
pointer, which is less likely to crash on a less permissive
termcap/terminfo implementation.

 * I'm aware of a seperate patch to add darkgray support -- but it was
unconditional at runtime, and had to change the color numbers in
includes/color.h to work.  My patch makes the TTY code independent of the
actual value of the CLR_* defines.

 * I personally believe the correct spelling of the color involved is
"grey", however I have adopted the popular misspelling "gray" throughout
to be consistent with the rest of nethack. :)

---- Michael Deutschmann <michael@talamasca.ocis.net>