Introduce the new type 'ncdirect', a stripped-down 'notcurses'
suitable for inline modification of regular output. Used the new
type because otherwise there were going to be if(directmode) checks
everywhere. Direct mode encompasses only colorizing and styling.
Add new man page notcurses_directmode(3). Add new section to README.
Add new PoC using direct mode RGB. Update demo table summary to use
direct mode.
As it turns out, we can't portably load the initial terminal contents
(there are some hacks of various EXTREME nature, but none of them are
worth it for the rather limited benefit). The O(1)-time damage
inference requires knowledge of what was previously present to
inibit unnecessary draws. We would then need some special cell value
indicating "not yet written to" to distinguish a purposeful null
cell from an initial cell. Again, we could do this, but for what value?
Finally, the idea of clearing new area on SIGWINCH was always flawed,
as we can't do that from a signal handler.
With the advent of direct mode #77, the reason for this largely goes
away in any case.
* palette_set: update pal256 damage map #230
* drone: use newest builders
* palette: send oc on exit for color reset #285
* palette_new: copy existing palette in #230
* Python: use checkRGB everywhere
* more palette unit testing
* add ncplane_set_*_palindex()
* render fg palindex #230
* palette index color is out of 1000
* jungle demo works #253
