In Sixel, we must supply a value for P2; essentially, 1
means that there are transparent pixels, while 0 means
there are not, or that we don't care what's already
present (P2=0 is implemented faster by some terminals).
We set P2=1 upon encountering a transparent pixel, or
after wiping a cell, but we weren't doing so when we
reloaded a bitmap and prewiped due to cached ANNIHILATION
values in the TAM. Do so. This fixes up the flickering
we saw in the yield demo, as we no longer printed over
the text. Furthermore, we can now properly return 0 from
sixel_wipe() on a cached wipe, eliminating a great many
invalidations and redraws. Move the ANNIHILATION check
into the shared code of sprite_wipe(), removing it from
sixel_wipe() and kitty_wipe().
Oh, what a happy, happy, happy day!
- remove `Nc` & `NcD` wrappers, to move them to notcurses-rs library.
- update the summary header format for Notcurses and NcDirect
- update docs and examples
With '\v' (vertical tab), we don't need force raw mode.
This saves us system calls, and makes the entire affair
more reliable (no race between setting up termios and
emitting '\n'; no chance for second tcsetattr to fail).
Thanks once more to @dnkl on #1625.
The cud capability to move the cursor down doesn't
scroll (and shouldn't be used on the last row). We
have no reliable knowledge of whether we're on the
last row or not, so instead switch to raw mode, emit
the newlines, and switch back to whatever mode we
were in. This method is due to @dnkl aka Daniel Eklöf,
a gentleman and scholar who absolutely knows his shit.
Closes#1625.