ncplane_as_rgba returns NULL after a blitting image with transparent background on a plane

[Albrict]

Please include the following data:

• export | egrep 'LANG|LC_CTYPE|TERM'

  declare -x COLORTERM="truecolor" declare -x GDM_LANG="en_US.UTF-8" declare -x LANG="en_US.UTF-8" declare -x TERM="alacritty"

• notcurses version (available from notcurses-demo i) notcurses-demo version 3.0.9

• terminal name + version Alacritty, version: 0.11.0-4

  Issue

  If you blit PNG image with transparent background on a plane, render it and then try get RGBA data from it using ncplane_as_rgba - you will get NULL. But if you load an image with some background - function will work properly. Same behavior if the plane is not filled, but have some graphics on it.

  Code

  include <notcurses/notcurses.h>

  int main(int argc, char *argv) {
  struct notcurses nc = notcurses_init(NULL, stdout); struct ncplane *std_plane = notcurses_stdplane(nc); struct ncvisual_options opts;

  memset(&opts, 0, sizeof(struct ncvisual_options));
  opts.n = std_plane;
  opts.x = 0;
  opts.y = 0;
  opts.begy = 0;
  opts.begx = 0;
  opts.lenx = ncplane_dim_x(std_plane);
  opts.leny = ncplane_dim_y(std_plane); 
  opts.blitter = NCBLIT_1x1;
  opts.pxoffx = 0;
  opts.pxoffy = 0;
  
  struct ncvisual *visual = ncvisual_from_file("test.png");
  ncvisual_resize(visual, opts.leny, opts.lenx);
  std_plane = ncvisual_blit(nc, visual, &opts);
  notcurses_render(nc);
  
  uint32_t *data = ncplane_as_rgba(std_plane, NCBLIT_1x1, 0, 0, ncplane_dim_y(std_plane), ncplane_dim_x(std_plane), NULL, NULL);
  if (data == NULL) {
      notcurses_stop(nc);
      fprintf(stderr, "Can't get rgba array\n");
      exit(EXIT_FAILURE);
  }
  notcurses_stop(nc);
  return EXIT_SUCCESS;

  }

[dankamongmen]

thanks for the quality report! i'll look into this asap.