Re: Advice for supporting custom colors

[Timothy Allen]

On Wed, 2019-01-09 at 13:26 -0600, Bryan Christ wrote:
> The challenge with supporting larger colors is that the native output
> for libvterm is a ncurses WINDOW.

I guess this is not really the advice you wanted to hear, but:

- the curses API, when it supports colour, supports 8 colours
guaranteed plus maybe more depending on runtime checks

- the terminfo database fundamentally assumes a terminal supports a
fixed number of colours, with no runtime checks

Therefore, the most straight-forward solution is "only support 8
colours". It's simple, straight-forward, and you've already written the
code, so there's no additional effort.

If you want to do something a bit more dynamic, maybe you can choose a
$TERM based on the capabilities ncurses advertises, so if `COLORS ==
256` then you use `TERM=libvterm-256color` instead of `TERM=libvterm`.
Maybe you do this already when libvterm is used inside a terminal that
doesn't support colour at all, like vt100.

If you want to use one rich data model everywhere, and do best-effort 
rendering depending on the capabilities of the outer terminal (like
tmux does), then you're going to need to use something other than an
ncurses WINDOW.