This is to make it possible, in the future, to create multiple instances
of `NotCurses` for multiple terminals. The first instance of
`NotCurses` becomes the default one, so that any instances of other
classes that aren't explicitly created with a pointer to another
`NotCurses` instance still work as expected.
Note that currently trying to call `notcurses_init` twice results in the
following error for me:
0x55555559bfc0 is already registered for signals
Couldn't drop signals: 0x55555559bfc0 != 0x5555555b6720
terminate called after throwing an instance of 'ncpp::init_error*'
Program received signal SIGABRT, Aborted.
The error is signalled by `setup_signals` and the pointer shown in the
message points to the first `struct notcurses` instance created.
Fixes: https://github.com/dankamongmen/notcurses/issues/616
SIGSEGV was caused by an invalid cast.
Short explanation: PEBKAC
Long explanation: `Selector.hh`, `Plot.hh` and `MultiSelector.hh` did
not include `Plane.hh`, they merely declared `class Plane;` because
inclusion of `Plane.hh` would cause circular dependencies to appear and
the compiler would be unhappy. On top of that, yours truly wrenched the
compiler's hands and caused it to believe that a pointer to `Plane` is
really a pointer to `ncplane*` which was quite a silly thing to do as
the compiler, not having included `Plane.hh` and thus not knowing full
definition of the type, wasn't able to look up the type cast operator in
`Plane`.
Don't abuse `reinterpret_cast`, kids!
Replace the singly-linked z-axis with a doubly-linked list,
and reimplement all z-axis moves as O(1) functions.
Eliminate ncplane_move_{above/below}_unsafe(), as there are no
longer unsafe moves.
ncplane_dup(): properly set target plane attributes/channels
ncplane_move_below_unsafe(): speedup, at most one traversal
ncplane_rgba(): accept null glyph
ncvisual_from_plane(): dup the plane, own it in ncvisual
normal: spin the visual
Unify ffmpeg/oiio/null implementations, where possible. This effectively
required placing all three in the same file, which meant they're all now
C++. Update FFmpeg implemenation to be C++-usable. Implement
ncvisual_rotate_cw() and ncvisual_rotate_ccw() #515. Move most of tetris
over to Visual from Plane #558. Add bgra_to_rgba(), necessary for
creating ncvisual from BGRA memory. Implement ncvisual_from_rgba()
and ncvisual_from_bgra() #557. Add unit tests on ncvisual rotation.
Marek Habersack
nick black