Unexpected behaviour with `NCPLANE_OPTION_MARGINALIZED` and `ncplane_resize_marginalized`

[sinny-13]

notcurses 3.0.17

I have been trying to use NCPLANE_OPTION_MARGINALIZED along with its recommended resize callback, ncplane_resize_marginalized, and I cannot get it to work as expected. I expect that I'm using it incorrectly, and would enjoy being told so!

Main terminal:

COLORTERM=truecolor
LANG=en_GB.UTF-8
TERM=xterm-ghostty
TERM_PROGRAM=ghostty
TERM_PROGRAM_VERSION=1.2.3

Same behaviour with:

LANG=en_GB.UTF-8
TERM=xterm-256color
TERM_PROGRAM=Apple_Terminal
TERM_PROGRAM_VERSION=455.1

as well as:

COLORTERM=truecolor
LANG=en_GB.UTF-8
LC_TERMINAL=iTerm2
LC_TERMINAL_VERSION=3.5.14
TERM=xterm-256color
TERMINFO_DIRS=/Applications/iTerm.app/Contents/Resources/terminfo:/usr/share/terminfo
TERM_PROGRAM=iTerm.app
TERM_PROGRAM_VERSION=3.5.14

I’ve built a fairly minimal example of it not working.

There seems to be two issues:

• The initial plane which should have a margin of 1 on each side, only has a margin on the left, and top.
• The resize sets the position of the inner plane somewhere way off.

Below is my main.c:

#include <locale.h>
#include <notcurses/notcurses.h>
#include <unistd.h>

int main(void) {

  setlocale(LC_ALL, "");

  struct notcurses_options opts = {.termtype = NULL};
  struct notcurses *nc = notcurses_init(&opts, NULL);
  if (!nc)
    return 1;

  struct ncplane *pl_std = notcurses_stdplane(nc);
  struct ncplane_options base_opts = {
      .cols = 40, .rows = 20, .x = 0, .y = 0, .name = "base"};
  struct ncplane *base = ncplane_create(pl_std, &base_opts);
  ncplane_set_base(base, "x", 0,
                   NCCHANNELS_INITIALIZER(0x10, 0x70, 0x00, 0x00, 0x00, 0x00));
  ncplane_erase(base);

  struct ncplane_options marg_p_opts = {.name = "marg",
                                        .cols = 0,
                                        .rows = 0,
                                        .x = 1,
                                        .y = 1,
                                        .margin_r = 1,
                                        .margin_b = 1,
                                        .resizecb =
                                            &ncplane_resize_marginalized,
                                        .flags = NCPLANE_OPTION_MARGINALIZED};
  struct ncplane *marg_p = ncplane_create(base, &marg_p_opts);
  ncplane_set_base(marg_p, "-", 0,
                   NCCHANNELS_INITIALIZER(0x00, 0x00, 0x00, 0x10, 0x70, 0x00));
  ncplane_erase(marg_p);

  notcurses_render(nc);
  sleep(4);

  ncplane_resize_simple(base, 10, 20);

  notcurses_render(nc);
  sleep(4);

  notcurses_stop(nc);
  return 0;
}

This image shows the initial planes, the inner of which should have a border of 1 on all edges.

This shows the planes after the call to ncplane_resize_simple, where the position of the inner plane is incorrect.

Any guidance would be appreciated.

Thanks!