notcurses_fade - fade ncplanes in and out

       nick black <nickblack@linux.com>.

                                                     v3.0.7                                    notcurses_fade(3)

       Palette  reprogramming  can affect other contents of the terminal in complex ways.  This is not a problem
       when the RGB method is used.

ncplane_fadeout,  ncplane_fadein,  and ncplane_pulse are simple APIs for fading planes in and out.  Fades
       require either RGB support or palette reprogramming support from the terminal (the  RGB  method  is  pre‐
       ferred, and will be used whenever possible).  The ts parameter specifies the total amount of time for the
       fade  operation.  The operation itself is time-adaptive (i.e.  if it finds itself falling behind, it will
       skip iterations; if it is proceeding too quickly, it will sleep).

       These are wrappers around the more flexible ncfadectx API.  Create  an  ncfadectx  with  ncfadectx_setup.
       The number of possible state changes (iterations) can be accessed with ncfadectx_iterations.  A state can
       be  reached  with  ncplane_fadeout_iteration or ncplane_fadein_iteration.  Finally, destroy the ncfadectx
       with ncfadectx_free.

       notcurses_fade - fade ncplanes in and out

ncplane_fadeout_iteration and ncplane_fadein_iteration will propagate out any non-zero return value  from
       the callback fader.

clock_nanosleep(2), notcurses(3), notcurses_plane(3)

#include<notcurses/notcurses.h>

              struct ncfadectx;

              // Called for each delta performed in a fade on ncp. If anything but 0 is
              // returned, the fading operation ceases immediately, and that value is
              // propagated out. If provided and not NULL, the faders will not themselves
              // call notcurses_render().
              typedef int (*fadecb)(struct notcurses* nc, struct ncplane* ncp,
                                    const struct timespec*, void* curry);

       boolnotcurses_canfade(conststructnotcurses*nc);intncplane_fadeout(structncplane*n,conststructtimespec*ts,fadecbfader,void*curry);intncplane_fadein(structncplane*n,conststructtimespec*ts,fadecbfader,void*curry);intncplane_pulse(structncplane*n,conststructtimespec*ts,fadecbfader,void*curry);structncfadectx*ncfadectx_setup(structncplane*n);intncfadectx_iterations(conststructncfadectx*nctx);intncplane_fadeout_iteration(structncplane*n,structncfadectx*nctx,intiter,fadecbfader,void*curry);intncplane_fadein_iteration(structncplane*n,structncfadectx*nctx,intiter,fadecbfader,void*curry);voidncfadectx_free(structncfadectx*nctx);