notcurses/tests/ncplane.cpp

#include <array>
#include <cstdlib>
#include <notcurses.h>
#include "internal.h"
#include "main.h"

void BoxPermutationsRounded(struct notcurses* nc, struct ncplane* n, unsigned edges) {
  int dimx, dimy;
  ncplane_dim_yx(n, &dimy, &dimx);
  REQUIRE(2 < dimy);
  REQUIRE(47 < dimx);
  // we'll try all 16 boxmasks in 3x3 configurations in a 1x16 map
  unsigned boxmask = edges << NCBOXCORNER_SHIFT;
  for(auto x0 = 0 ; x0 < 16 ; ++x0){
    CHECK(0 == ncplane_cursor_move_yx(n, 0, x0 * 3));
    CHECK(0 == ncplane_rounded_box_sized(n, 0, 0, 3, 3, boxmask));
    ++boxmask;
  }
  CHECK(0 == notcurses_render(nc));
}

TEST_CASE("NCPlane") {
  if(getenv("TERM") == nullptr){
    return;
  }
  notcurses_options nopts{};
  nopts.inhibit_alternate_screen = true;
  nopts.suppress_banner = true;
  FILE* outfp_ = fopen("/dev/tty", "wb");
  REQUIRE(outfp_);
  struct notcurses* nc_ = notcurses_init(&nopts, outfp_);
  REQUIRE(nc_);
  struct ncplane* n_ = notcurses_stdplane(nc_);
  REQUIRE(n_);

  // Starting position ought be 0, 0 (the origin)
  SUBCASE("StdPlanePosition") {
    int x, y;
    ncplane_cursor_yx(n_, &y, &x);
    CHECK(0 == x);
    CHECK(0 == y);
  }

  // Dimensions of the standard plane ought be the same as those of the context
  SUBCASE("StdPlaneDimensions") {
    int cols, rows;
    notcurses_term_dim_yx(nc_, &rows, &cols);
    int ncols, nrows;
    ncplane_dim_yx(n_, &nrows, &ncols);
    CHECK(rows == nrows);
    CHECK(cols == ncols);
  }

  // Verify that we can move to all four coordinates of the standard plane
  SUBCASE("MoveStdPlaneDimensions") {
    int cols, rows;
    notcurses_term_dim_yx(nc_, &rows, &cols);
    CHECK(0 == ncplane_cursor_move_yx(n_, 0, 0));
    int x, y;
    ncplane_cursor_yx(n_, &y, &x);
    CHECK(y == 0);
    CHECK(x == 0);
    CHECK(0 == ncplane_cursor_move_yx(n_, rows - 1, 0));
    ncplane_cursor_yx(n_, &y, &x);
    CHECK(y == rows - 1);
    CHECK(x == 0);
    CHECK(0 == ncplane_cursor_move_yx(n_, rows - 1, cols - 1));
    ncplane_cursor_yx(n_, &y, &x);
    CHECK(y == rows - 1);
    CHECK(x == cols - 1);
    CHECK(0 == ncplane_cursor_move_yx(n_, 0, cols - 1));
    ncplane_cursor_yx(n_, &y, &x);
    CHECK(y == 0);
    CHECK(x == cols - 1);
  }

  // Verify that we can move to all four coordinates of the standard plane
  SUBCASE("MoveBeyondPlaneFails") {
    int cols, rows;
    notcurses_term_dim_yx(nc_, &rows, &cols);
    CHECK(0 > ncplane_cursor_move_yx(n_, -2, 0));
    CHECK(0 > ncplane_cursor_move_yx(n_, -2, -2));
    CHECK(0 > ncplane_cursor_move_yx(n_, 0, -2));
    CHECK(0 > ncplane_cursor_move_yx(n_, rows - 1, -2));
    CHECK(0 > ncplane_cursor_move_yx(n_, rows, 0));
    CHECK(0 > ncplane_cursor_move_yx(n_, rows + 1, 0));
    CHECK(0 > ncplane_cursor_move_yx(n_, rows, cols));
    CHECK(0 > ncplane_cursor_move_yx(n_, -2, cols - 1));
    CHECK(0 > ncplane_cursor_move_yx(n_, 0, cols));
    CHECK(0 > ncplane_cursor_move_yx(n_, 0, cols + 1));
  }

  SUBCASE("SetPlaneRGB") {
    CHECK(0 == ncplane_set_fg_rgb(n_, 0, 0, 0));
    CHECK(0 == ncplane_set_fg_rgb(n_, 255, 255, 255));
    CHECK(0 == notcurses_render(nc_));
  }

  SUBCASE("RejectBadRGB") {
    CHECK(0 > ncplane_set_fg_rgb(n_, -1, 0, 0));
    CHECK(0 > ncplane_set_fg_rgb(n_, 0, -1, 0));
    CHECK(0 > ncplane_set_fg_rgb(n_, 0, 0, -1));
    CHECK(0 > ncplane_set_fg_rgb(n_, -1, -1, -1));
    CHECK(0 > ncplane_set_fg_rgb(n_, 256, 255, 255));
    CHECK(0 > ncplane_set_fg_rgb(n_, 255, 256, 255));
    CHECK(0 > ncplane_set_fg_rgb(n_, 255, 255, 256));
    CHECK(0 > ncplane_set_fg_rgb(n_, 256, 256, 256));
  }

  // Verify we can emit a multibyte character, and it advances the cursor
  SUBCASE("EmitCell") {
    const char cchar[] = "✔";
    cell c{};
    CHECK(strlen(cchar) == cell_load(n_, &c, cchar));
    CHECK(0 < ncplane_putc(n_, &c));
    int x, y;
    ncplane_cursor_yx(n_, &y, &x);
    CHECK(0 == y);
    CHECK(1 == x);
    CHECK(0 == notcurses_render(nc_));
  }

  // Verify we can emit a wide character, and it advances the cursor
  SUBCASE("EmitWchar") {
    const wchar_t* w = L"✔";
    int sbytes = 0;
    CHECK(0 < ncplane_putwegc(n_, w, 0, 0, &sbytes));
    int x, y;
    ncplane_cursor_yx(n_, &y, &x);
    CHECK(0 == y);
    CHECK(1 == x);
    CHECK(0 == notcurses_render(nc_));
  }

  // Verify we can emit a multibyte string, and it advances the cursor
  SUBCASE("EmitStr") {
    const char s[] = "Σιβυλλα τι θελεις; respondebat illa: αποθανειν θελω.";
    int wrote = ncplane_putstr(n_, s);
    CHECK(strlen(s) == wrote);
    int x, y;
    ncplane_cursor_yx(n_, &y, &x);
    CHECK(0 == y);
    CHECK(1 <= x); // FIXME tighten in on this
    CHECK(0 == notcurses_render(nc_));
  }

  // Verify we can emit a wide string, and it advances the cursor
  SUBCASE("EmitWideStr") {
    const wchar_t s[] = L"Σιβυλλα τι θελεις; respondebat illa: αποθανειν θελω.";
    int wrote = ncplane_putwstr(n_, s);
    CHECK(0 < wrote);
    int x, y;
    ncplane_cursor_yx(n_, &y, &x);
    CHECK(0 == y);
    CHECK(1 <= x); // FIXME tighten in on this
    CHECK(0 == notcurses_render(nc_));
  }

  SUBCASE("EmitEmojiStr") {
    const wchar_t e[] =
      L"🍺🚬🌿💉💊🔫💣🤜🤛🐌🐎🐑🐒🐔🐗🐘🐙🐚"
      "🐛🐜🐝🐞🐟🐠🐡🐢🐣🐤🐥🐦🐧🐨🐩🐫🐬🐭🐮"
      "🐯🐰🐱🐲🐳🐴🐵🐶🐷🐹🐺🐻🐼🦉🐊🦕🦖🐬🐙🦠🦀";
    int wrote = ncplane_putwstr(n_, e);
    CHECK(0 < wrote);
    int x, y;
    ncplane_cursor_yx(n_, &y, &x);
    CHECK_LE(0, y);
    CHECK(1 <= x); // FIXME tighten in on this
    CHECK(0 == notcurses_render(nc_));
  }

  SUBCASE("HorizontalLines") {
    int x, y;
    ncplane_dim_yx(n_, &y, &x);
    REQUIRE(0 < y);
    REQUIRE(0 < x);
    cell c{};
    cell_load(n_, &c, "-");
    for(int yidx = 0 ; yidx < y ; ++yidx){
      CHECK(0 == ncplane_cursor_move_yx(n_, yidx, 1));
      CHECK(x - 2 == ncplane_hline(n_, &c, x - 2));
      int posx, posy;
      ncplane_cursor_yx(n_, &posy, &posx);
      CHECK(yidx == posy);
      CHECK(x - 1 == posx);
    }
    cell_release(n_, &c);
    CHECK(0 == notcurses_render(nc_));
  }

  SUBCASE("VerticalLines") {
    int x, y;
    ncplane_dim_yx(n_, &y, &x);
    REQUIRE(0 < y);
    REQUIRE(0 < x);
    cell c{};
    cell_load(n_, &c, "|");
    for(int xidx = 1 ; xidx < x - 1 ; ++xidx){
      CHECK(0 == ncplane_cursor_move_yx(n_, 1, xidx));
      CHECK(y - 2 == ncplane_vline(n_, &c, y - 2));
      int posx, posy;
      ncplane_cursor_yx(n_, &posy, &posx);
      CHECK(y - 2 == posy);
      CHECK(xidx == posx - 1);
    }
    cell_release(n_, &c);
    CHECK(0 == notcurses_render(nc_));
  }

  // reject attempts to draw boxes beyond the boundaries of the ncplane
  SUBCASE("BadlyPlacedBoxen") {
    int x, y;
    ncplane_dim_yx(n_, &y, &x);
    REQUIRE(2 < y);
    REQUIRE(2 < x);
    cell ul{}, ll{}, lr{}, ur{}, hl{}, vl{};
    REQUIRE(0 == cells_rounded_box(n_, 0, 0, &ul, &ur, &ll, &lr, &hl, &vl));
    CHECK_GT(0, ncplane_box(n_, &ul, &ur, &ll, &lr, &hl, &vl, y + 1, x + 1, 0));
    CHECK(0 == ncplane_cursor_move_yx(n_, 1, 0));
    CHECK_GT(0, ncplane_box(n_, &ul, &ur, &ll, &lr, &hl, &vl, y, x, 0));
    CHECK(0 == ncplane_cursor_move_yx(n_, 0, 1));
    CHECK_GT(0, ncplane_box(n_, &ul, &ur, &ll, &lr, &hl, &vl, y, x, 0));
    CHECK(0 == ncplane_cursor_move_yx(n_, y - 1, x - 1));
    CHECK_GT(0, ncplane_box(n_, &ul, &ur, &ll, &lr, &hl, &vl, 2, 2, 0));
    CHECK(0 == ncplane_cursor_move_yx(n_, y - 2, x - 1));
    CHECK_GT(0, ncplane_box(n_, &ul, &ur, &ll, &lr, &hl, &vl, 2, 2, 0));
    CHECK(0 == ncplane_cursor_move_yx(n_, y - 1, x - 2));
    CHECK_GT(0, ncplane_box(n_, &ul, &ur, &ll, &lr, &hl, &vl, 2, 2, 0));
    CHECK(0 == notcurses_render(nc_));
  }

  SUBCASE("BoxPermutationsRoundedZeroEdges") {
    BoxPermutationsRounded(nc_, n_, 0);
  }

  SUBCASE("BoxPermutationsRoundedOneEdges") {
    BoxPermutationsRounded(nc_, n_, 1);
  }

  SUBCASE("BoxPermutationsRoundedTwoEdges") {
    BoxPermutationsRounded(nc_, n_, 2);
  }

  SUBCASE("BoxPermutationsRoundedThreeEdges") {
    BoxPermutationsRounded(nc_, n_, 3);
  }

  SUBCASE("BoxPermutationsDouble") {
    int dimx, dimy;
    ncplane_dim_yx(n_, &dimy, &dimx);
    REQUIRE(2 < dimx);
    REQUIRE(47 < dimx);
    // we'll try all 16 boxmasks in 3x3 configurations in a 1x16 map
    unsigned boxmask = 0;
    for(auto x0 = 0 ; x0 < 16 ; ++x0){
      CHECK(0 == ncplane_cursor_move_yx(n_, 0, x0 * 3));
      CHECK(0 == ncplane_double_box_sized(n_, 0, 0, 3, 3, boxmask));
      ++boxmask;
    }
    CHECK(0 == notcurses_render(nc_));
  }

  SUBCASE("PerimeterRoundedBox") {
    int x, y;
    ncplane_dim_yx(n_, &y, &x);
    REQUIRE(2 < y);
    REQUIRE(2 < x);
    REQUIRE(0 == ncplane_cursor_move_yx(n_, 0, 0));
    CHECK(0 == ncplane_rounded_box(n_, 0, 0, y - 1, x - 1, 0));
    CHECK(0 == notcurses_render(nc_));
  }

  SUBCASE("PerimeterRoundedBoxSized") {
    int x, y;
    ncplane_dim_yx(n_, &y, &x);
    REQUIRE(2 < y);
    REQUIRE(2 < x);
    REQUIRE(0 == ncplane_cursor_move_yx(n_, 0, 0));
    CHECK(0 == ncplane_rounded_box_sized(n_, 0, 0, y, x, 0));
    CHECK(0 == notcurses_render(nc_));
  }

  SUBCASE("PerimeterDoubleBox") {
    int x, y;
    ncplane_dim_yx(n_, &y, &x);
    REQUIRE(2 < y);
    REQUIRE(2 < x);
    REQUIRE(0 == ncplane_cursor_move_yx(n_, 0, 0));
    CHECK(0 == ncplane_double_box(n_, 0, 0, y - 1, x - 1, 0));
    CHECK(0 == notcurses_render(nc_));
  }

  SUBCASE("PerimeterDoubleBoxSized") {
    int x, y;
    ncplane_dim_yx(n_, &y, &x);
    REQUIRE(2 < y);
    REQUIRE(2 < x);
    REQUIRE(0 == ncplane_cursor_move_yx(n_, 0, 0));
    CHECK(0 == ncplane_double_box_sized(n_, 0, 0, y, x, 0));
    CHECK(0 == notcurses_render(nc_));
  }

  SUBCASE("EraseScreen") {
    ncplane_erase(n_);
    CHECK(0 == notcurses_render(nc_));
  }

  // we're gonna run both a composed latin a with grave, and then a latin a with
  // a combining nonspacing grave
  SUBCASE("CellLoadCombining") {
    const char* w1 = "à"; // U+00E0, U+0000         (c3 a0)
    const char* w2 = "à"; // U+0061, U+0300, U+0000 (61 cc 80)
    const char* w3 = "a"; // U+0061, U+0000         (61)
    cell cell1 = CELL_TRIVIAL_INITIALIZER;
    cell cell2 = CELL_TRIVIAL_INITIALIZER;
    cell cell3 = CELL_TRIVIAL_INITIALIZER;
    auto u1 = cell_load(n_, &cell1, w1);
    auto u2 = cell_load(n_, &cell2, w2);
    auto u3 = cell_load(n_, &cell3, w3);
    REQUIRE(2 == u1);
    REQUIRE(3 == u2);
    REQUIRE(1 == u3);
    cell_release(n_, &cell1);
    cell_release(n_, &cell2);
    cell_release(n_, &cell3);
  }

  SUBCASE("CellDuplicateCombining") {
    const char* w1 = "à"; // U+00E0, U+0000         (c3 a0)
    const char* w2 = "à"; // U+0061, U+0300, U+0000 (61 cc 80)
    const char* w3 = "a"; // U+0061, U+0000         (61)
    cell cell1 = CELL_TRIVIAL_INITIALIZER;
    cell cell2 = CELL_TRIVIAL_INITIALIZER;
    cell cell3 = CELL_TRIVIAL_INITIALIZER;
    auto u1 = cell_load(n_, &cell1, w1);
    auto u2 = cell_load(n_, &cell2, w2);
    auto u3 = cell_load(n_, &cell3, w3);
    REQUIRE(2 == u1);
    REQUIRE(3 == u2);
    REQUIRE(1 == u3);
    cell cell4 = CELL_TRIVIAL_INITIALIZER;
    cell cell5 = CELL_TRIVIAL_INITIALIZER;
    cell cell6 = CELL_TRIVIAL_INITIALIZER;
    CHECK(2 == cell_duplicate(n_, &cell4, &cell1));
    CHECK(3 == cell_duplicate(n_, &cell5, &cell2));
    CHECK(1 == cell_duplicate(n_, &cell6, &cell3));
    cell_release(n_, &cell1);
    cell_release(n_, &cell2);
    cell_release(n_, &cell3);
    cell_release(n_, &cell4);
    cell_release(n_, &cell5);
    cell_release(n_, &cell6);
  }

  SUBCASE("CellMultiColumn") {
    const char* w1 = "\xf0\x9f\x91\xa9"; // U+1F469 WOMAN
    const char* w2 = "N";
    cell c1 = CELL_TRIVIAL_INITIALIZER;
    cell c2 = CELL_TRIVIAL_INITIALIZER;
    auto u1 = cell_load(n_, &c1, w1);
    auto u2 = cell_load(n_, &c2, w2);
    REQUIRE(0 < u1);
    REQUIRE(0 < u2);
    REQUIRE(strlen(w1) == u1);
    REQUIRE(strlen(w2) == u2);
    CHECK(cell_double_wide_p(&c1));
    CHECK_FALSE(cell_double_wide_p(&c2));
    cell_release(n_, &c1);
    cell_release(n_, &c2);
  }

  // verifies that the initial userptr is what we provided, that it is a nullptr
  // for the standard plane, and that we can change it.
  SUBCASE("UserPtr") {
    CHECK(nullptr == ncplane_userptr(n_));
    int x, y;
    void* sentinel = &x;
    notcurses_term_dim_yx(nc_, &y, &x);
    struct ncplane* ncp = ncplane_new(nc_, y, x, 0, 0, sentinel);
    REQUIRE(ncp);
    CHECK(&x == ncplane_userptr(ncp));
    CHECK(sentinel == ncplane_set_userptr(ncp, nullptr));
    CHECK(nullptr == ncplane_userptr(ncp));
    sentinel = &y;
    CHECK(nullptr == ncplane_set_userptr(ncp, sentinel));
    CHECK(&y == ncplane_userptr(ncp));
    CHECK(0 == ncplane_destroy(ncp));
  }

  // create a new plane, the same size as the terminal, and verify that it
  // occupies the same dimensions as the standard plane.
  SUBCASE("NewPlaneSameSize") {
    int x, y;
    notcurses_term_dim_yx(nc_, &y, &x);
    struct ncplane* ncp = ncplane_new(nc_, y, x, 0, 0, nullptr);
    REQUIRE(ncp);
    int px, py;
    ncplane_dim_yx(ncp, &py, &px);
    CHECK(y == py);
    CHECK(x == px);
    int sx, sy;
    ncplane_dim_yx(n_, &sy, &sx);
    CHECK(sy == py);
    CHECK(sx == px);
    CHECK(0 == ncplane_destroy(ncp));
  }

  SUBCASE("ShrinkPlane") {
    int maxx, maxy;
    int x = 0, y = 0;
    notcurses_term_dim_yx(nc_, &maxy, &maxx);
    struct ncplane* newp = ncplane_new(nc_, maxy, maxx, y, x, nullptr);
    REQUIRE(newp);
    CHECK(0 == notcurses_render(nc_));
    while(y > 4 && x > 4){
      maxx -= 2;
      maxy -= 2;
      ++x;
      ++y;
      REQUIRE(0 == ncplane_resize(newp, 1, 1, maxy, maxx, 1, 1, maxy, maxx));
      CHECK(0 == notcurses_render(nc_));
      // FIXME check dims, pos
    }
    while(y > 4){
      maxy -= 2;
      ++y;
      REQUIRE(0 == ncplane_resize(newp, 1, 0, maxy, maxx, 1, 0, maxy, maxx));
      CHECK(0 == notcurses_render(nc_));
      // FIXME check dims, pos
    }
    while(x > 4){
      maxx -= 2;
      ++x;
      REQUIRE(0 == ncplane_resize(newp, 0, 1, maxy, maxx, 0, 1, maxy, maxx));
      CHECK(0 == notcurses_render(nc_));
      // FIXME check dims, pos
    }
    REQUIRE(0 == ncplane_resize(newp, 0, 0, 0, 0, 0, 0, 2, 2));
    CHECK(0 == notcurses_render(nc_));
    // FIXME check dims, pos
    REQUIRE(0 == ncplane_destroy(newp));
  }

  SUBCASE("GrowPlane") {
    int maxx = 2, maxy = 2;
    int x = 0, y = 0;
    int dimy, dimx;
    notcurses_term_dim_yx(nc_, &dimy, &dimx);
    x = dimx / 2 - 1;
    y = dimy / 2 - 1;
    struct ncplane* newp = ncplane_new(nc_, maxy, maxx, y, x, nullptr);
    REQUIRE(newp);
    while(dimx - maxx > 4 && dimy - maxy > 4){
      maxx += 2;
      maxy += 2;
      --x;
      --y;
      // REQUIRE(0 == ncplane_resize(newp, 1, 1, maxy, maxx, 1, 1, maxy, maxx));
      // FIXME check dims, pos
    }
    while(y < dimy){
      ++maxy;
      if(y){
        ++y;
      }
      // REQUIRE(0 == ncplane_resize(newp, 1, 0, maxy, maxx, 1, 0, maxy, maxx));
      // FIXME check dims, pos
    }
    while(x < dimx){
      ++maxx;
      if(x){
        ++x;
      }
      // REQUIRE(0 == ncplane_resize(newp, 0, 1, maxy, maxx, 0, 1, maxy, maxx));
      // FIXME check dims, pos
    }
    REQUIRE(0 == ncplane_resize(newp, 0, 0, 0, 0, 0, 0, dimy, dimx));
    // FIXME check dims, pos
    REQUIRE(0 == ncplane_destroy(newp));
  }

  // we ought be able to see what we're about to render, or have just rendered, or
  // in any case whatever's in the virtual framebuffer for a plane
  SUBCASE("PlaneAtCursorSimples"){
    const char STR1[] = "Jackdaws love my big sphinx of quartz";
    const char STR2[] = "Cwm fjord bank glyphs vext quiz";
    const char STR3[] = "Pack my box with five dozen liquor jugs";
    ncplane_styles_set(n_, 0);
    REQUIRE(0 == ncplane_cursor_move_yx(n_, 0, 0));
    REQUIRE(0 < ncplane_putstr(n_, STR1));
    int dimy, dimx;
    ncplane_dim_yx(n_, &dimy, &dimx);
    REQUIRE(0 == ncplane_cursor_move_yx(n_, 1, dimx - strlen(STR2)));
    REQUIRE(0 < ncplane_putstr(n_, STR2));
    int y, x;
    ncplane_cursor_yx(n_, &y, &x);
    REQUIRE(2 == y);
    REQUIRE(0 == x);
    REQUIRE(0 < ncplane_putstr(n_, STR3));
    cell testcell = CELL_TRIVIAL_INITIALIZER;
    REQUIRE(0 == ncplane_at_cursor(n_, &testcell)); // want nothing at the cursor
    CHECK(0 == testcell.gcluster);
    CHECK(0 == testcell.attrword);
    CHECK(0 == testcell.channels);
    REQUIRE(0 == ncplane_cursor_move_yx(n_, 0, 0));
    REQUIRE(0 < ncplane_at_cursor(n_, &testcell)); // want first char of STR1
    CHECK(STR1[0] == testcell.gcluster);
    CHECK(0 == testcell.attrword);
    CHECK(0 == testcell.channels);
    REQUIRE(0 == ncplane_cursor_move_yx(n_, 1, dimx - 1));
    REQUIRE(0 < ncplane_at_cursor(n_, &testcell)); // want last char of STR2
    CHECK(STR2[strlen(STR2) - 1] == testcell.gcluster);
    CHECK(0 == testcell.attrword);
    CHECK(0 == testcell.channels);
    // FIXME maybe check all cells?
    CHECK(0 == notcurses_render(nc_));
  }

  // ensure we read back what's expected for latinesque complex characters
  SUBCASE("PlaneAtCursorComplex"){
    const char STR1[] = "Σιβυλλα τι θελεις; respondebat illa:";
    const char STR2[] = "αποθανειν θελω";
    const char STR3[] = "Война и мир"; // just thrown in to complicate things
    ncplane_styles_set(n_, 0);
    REQUIRE(0 == ncplane_cursor_move_yx(n_, 0, 0));
    REQUIRE(0 < ncplane_putstr(n_, STR1));
    int dimy, dimx;
    ncplane_dim_yx(n_, &dimy, &dimx);
    REQUIRE(0 == ncplane_cursor_move_yx(n_, 1, dimx - mbstowcs(NULL, STR2, 0)));
    REQUIRE(0 < ncplane_putstr(n_, STR2));
    int y, x;
    ncplane_cursor_yx(n_, &y, &x);
    REQUIRE(2 == y);
    REQUIRE(0 == x);
    REQUIRE(0 < ncplane_putstr(n_, STR3));
    cell testcell = CELL_TRIVIAL_INITIALIZER;
    ncplane_at_cursor(n_, &testcell); // should be nothing at the cursor
    CHECK(0 == testcell.gcluster);
    CHECK(0 == testcell.attrword);
    CHECK(0 == testcell.channels);
    REQUIRE(0 == ncplane_cursor_move_yx(n_, 0, 0));
    REQUIRE(0 < ncplane_at_cursor(n_, &testcell)); // want first char of STR1
    CHECK(!strcmp("Σ", cell_extended_gcluster(n_, &testcell)));
    CHECK(0 == testcell.attrword);
    CHECK(0 == testcell.channels);
    REQUIRE(0 == ncplane_cursor_move_yx(n_, 1, dimx - mbstowcs(NULL, STR2, 0)));
    REQUIRE(0 < ncplane_at_cursor(n_, &testcell)); // want first char of STR2
    CHECK(!strcmp("α", cell_extended_gcluster(n_, &testcell)));
    CHECK(0 == testcell.attrword);
    CHECK(0 == testcell.channels);
    // FIXME maybe check all cells?
    CHECK(0 == notcurses_render(nc_));
  }

  // half-width, double-width, huge-yet-narrow, all that crap
  SUBCASE("PlaneAtCursorInsane"){
    const char EGC0[] = "\uffe0"; // fullwidth cent sign ￠
    const char EGC1[] = "\u00c5"; // neutral A with ring above Å
    const char EGC2[] = "\u20a9"; // half-width won ₩
    const char EGC3[] = "\u212b"; // ambiguous angstrom Å
    const char EGC4[] = "\ufdfd"; // neutral yet huge bismillah ﷽
    std::array<cell, 5> tcells;
    for(auto i = 0u ; i < tcells.size() ; ++i){
      cell_init(&tcells[i]);
    }
    REQUIRE(1 < cell_load(n_, &tcells[0], EGC0));
    REQUIRE(1 < cell_load(n_, &tcells[1], EGC1));
    REQUIRE(1 < cell_load(n_, &tcells[2], EGC2));
    REQUIRE(1 < cell_load(n_, &tcells[3], EGC3));
    REQUIRE(1 < cell_load(n_, &tcells[4], EGC4));
    for(auto i = 0u ; i < tcells.size() ; ++i){
      REQUIRE(0 < ncplane_putc(n_, &tcells[i]));
    }
    CHECK(0 == notcurses_render(nc_));
    int x = 0;
    for(auto i = 0u ; i < tcells.size() ; ++i){
      CHECK(0 == ncplane_cursor_move_yx(n_, 0, x));
      cell testcell = CELL_TRIVIAL_INITIALIZER;
      REQUIRE(0 < ncplane_at_cursor(n_, &testcell));
      CHECK(!strcmp(cell_extended_gcluster(n_, &tcells[i]),
                    cell_extended_gcluster(n_, &testcell)));
      CHECK(0 == testcell.attrword);
      wchar_t w;
      REQUIRE(0 < mbtowc(&w, cell_extended_gcluster(n_, &tcells[i]), MB_CUR_MAX));
      if(wcwidth(w) == 2){
        CHECK(CELL_WIDEASIAN_MASK == testcell.channels);
        ++x;
      }else{
        CHECK(0 == testcell.channels);
      }
      ++x;
    }
  }

  // test that we read back correct attrs/colors despite changing defaults
  SUBCASE("PlaneAtCursorAttrs"){
    const char STR1[] = "this has been a world destroyer production";
    const char STR2[] = "not to mention dank";
    const char STR3[] = "da chronic lives";
    ncplane_styles_set(n_, CELL_STYLE_BOLD);
    REQUIRE(0 < ncplane_putstr(n_, STR1));
    int y, x;
    ncplane_cursor_yx(n_, &y, &x);
    CHECK(0 == ncplane_cursor_move_yx(n_, y + 1, x - strlen(STR2)));
    ncplane_styles_on(n_, CELL_STYLE_ITALIC);
    REQUIRE(0 < ncplane_putstr(n_, STR2));
    CHECK(0 == ncplane_cursor_move_yx(n_, y + 2, x - strlen(STR3)));
    ncplane_styles_off(n_, CELL_STYLE_BOLD);
    REQUIRE(0 < ncplane_putstr(n_, STR3));
    ncplane_styles_off(n_, CELL_STYLE_ITALIC);
    CHECK(0 == notcurses_render(nc_));
    int newx;
    ncplane_cursor_yx(n_, &y, &newx);
    CHECK(newx == x);
    cell testcell = CELL_TRIVIAL_INITIALIZER;
    CHECK(0 == ncplane_cursor_move_yx(n_, y - 2, x - 1));
    REQUIRE(1 == ncplane_at_cursor(n_, &testcell));
    CHECK(testcell.gcluster == STR1[strlen(STR1) - 1]);
    CHECK(0 == ncplane_cursor_move_yx(n_, y - 1, x - 1));
    REQUIRE(1 == ncplane_at_cursor(n_, &testcell));
    CHECK(testcell.gcluster == STR2[strlen(STR2) - 1]);
    CHECK(0 == ncplane_cursor_move_yx(n_, y, x - 1));
    REQUIRE(1 == ncplane_at_cursor(n_, &testcell));
    CHECK(testcell.gcluster == STR3[strlen(STR3) - 1]);
  }

  SUBCASE("BoxGradients") {
    const auto sidesz = 5;
    int dimx, dimy;
    ncplane_dim_yx(n_, &dimy, &dimx);
    REQUIRE(20 < dimy);
    REQUIRE(40 < dimx);
    cell ul{}, ll{}, lr{}, ur{}, hl{}, vl{};
    REQUIRE(0 == cells_double_box(n_, 0, 0, &ul, &ur, &ll, &lr, &hl, &vl));
    CHECK(0 == channels_set_fg_rgb(&ul.channels, 255, 0, 0));
    CHECK(0 == channels_set_fg_rgb(&ur.channels, 0, 255, 0));
    CHECK(0 == channels_set_fg_rgb(&ll.channels, 0, 0, 255));
    CHECK(0 == channels_set_fg_rgb(&lr.channels, 255, 255, 255));
    CHECK(0 == channels_set_bg_rgb(&ul.channels, 0, 255, 255));
    CHECK(0 == channels_set_bg_rgb(&ur.channels, 255, 0, 255));
    CHECK(0 == channels_set_bg_rgb(&ll.channels, 255, 255, 0));
    CHECK(0 == channels_set_bg_rgb(&lr.channels, 0, 0, 0));
    // we'll try all 16 gradmasks in sideszXsidesz configs in a 4x4 map
    unsigned gradmask = 0;
    for(auto y0 = 0 ; y0 < 4 ; ++y0){
      for(auto x0 = 0 ; x0 < 4 ; ++x0){
        CHECK(0 == ncplane_cursor_move_yx(n_, y0 * sidesz, x0 * (sidesz + 1)));
        CHECK(0 == ncplane_box_sized(n_, &ul, &ur, &ll, &lr, &hl, &vl,
                                      sidesz, sidesz, gradmask << 4u));
        ++gradmask;
      }
    }
    gradmask = 0;
    for(auto y0 = 0 ; y0 < 4 ; ++y0){
      for(auto x0 = 0 ; x0 < 4 ; ++x0){
        CHECK(0 == ncplane_cursor_move_yx(n_, y0 * sidesz, x0 * (sidesz + 1) + (4 * (sidesz + 1))));
        CHECK(0 == ncplane_box_sized(n_, &ul, &ur, &ll, &lr, &hl, &vl,
                                      sidesz, sidesz, gradmask << 4u));
        ++gradmask;
      }
    }
    CHECK(0 == notcurses_render(nc_));
  }

  SUBCASE("BoxSideColors") {
    const auto sidesz = 5;
    int dimx, dimy;
    ncplane_dim_yx(n_, &dimy, &dimx);
    REQUIRE(20 < dimy);
    REQUIRE(40 < dimx);
    cell ul{}, ll{}, lr{}, ur{}, hl{}, vl{};
    REQUIRE(0 == cells_rounded_box(n_, 0, 0, &ul, &ur, &ll, &lr, &hl, &vl));
    // we'll try all 16 boxmasks in sideszXsidesz configurations in a 4x4 map
    CHECK(0 == channels_set_fg_rgb(&ul.channels, 255, 0, 0));
    CHECK(0 == channels_set_fg_rgb(&ur.channels, 0, 255, 0));
    CHECK(0 == channels_set_fg_rgb(&ll.channels, 0, 0, 255));
    CHECK(0 == channels_set_fg_rgb(&lr.channels, 0, 0, 0));
    CHECK(0 == channels_set_bg_rgb(&ul.channels, 0, 255, 255));
    CHECK(0 == channels_set_bg_rgb(&ur.channels, 255, 0, 255));
    CHECK(0 == channels_set_bg_rgb(&ll.channels, 255, 255, 0));
    CHECK(0 == channels_set_bg_rgb(&lr.channels, 0, 0, 0));
    CHECK(0 == channels_set_fg_rgb(&hl.channels, 255, 0, 255));
    CHECK(0 == channels_set_fg_rgb(&vl.channels, 255, 255, 255));
    CHECK(0 == channels_set_bg_rgb(&hl.channels, 0, 255, 0));
    CHECK(0 == channels_set_bg_rgb(&vl.channels, 0, 0, 0));
    for(auto y0 = 0 ; y0 < 4 ; ++y0){
      for(auto x0 = 0 ; x0 < 4 ; ++x0){
        CHECK(0 == ncplane_cursor_move_yx(n_, y0 * sidesz, x0 * (sidesz + 1)));
        CHECK(0 == ncplane_box_sized(n_, &ul, &ur, &ll, &lr, &hl, &vl,
                                      sidesz, sidesz, 0));
      }
    }
    for(auto y0 = 0 ; y0 < 4 ; ++y0){
      for(auto x0 = 0 ; x0 < 4 ; ++x0){
        CHECK(0 == ncplane_cursor_move_yx(n_, y0 * sidesz, x0 * (sidesz + 1) + (4 * (sidesz + 1))));
        CHECK(0 == ncplane_box_sized(n_, &ul, &ur, &ll, &lr, &hl, &vl,
                                      sidesz, sidesz, 0));
      }
    }
    CHECK(0 == notcurses_render(nc_));
  }

  SUBCASE("RightToLeft") {
    // give us some room on both sides
    CHECK(0 == ncplane_cursor_move_yx(n_, 1, 10));
    int sbytes = -1;
    CHECK(0 < ncplane_putegc(n_, "־", 0, 0, &sbytes));
    CHECK(0 == notcurses_render(nc_));
    CHECK(0 == ncplane_cursor_move_yx(n_, 3, 10));
    CHECK(0 < ncplane_putstr(n_, "I can write English with מילים בעברית in the same sentence."));
    CHECK(0 == ncplane_cursor_move_yx(n_, 5, 10));
    CHECK(0 < ncplane_putstr(n_, "|🔥|I have not yet ־ begun to hack|🔥|"));
    CHECK(0 == ncplane_cursor_move_yx(n_, 7, 10));
    CHECK(0 < ncplane_putstr(n_, "㉀㉁㉂㉃㉄㉅㉆㉇㉈㉉㉊㉋㉌㉍㉎㉏㉐㉑㉒㉓㉔㉕㉖㉗㉘㉙㉚㉛㉜㉝㉞㉟"));
    CHECK(0 == notcurses_render(nc_));
  }

  SUBCASE("NewPlaneOnRight") {
    int ncols, nrows;
    ncplane_dim_yx(n_, &nrows, &ncols);
    cell ul{}, ll{}, lr{}, ur{}, hl{}, vl{};
    int y, x;
    ncplane_yx(n_, &y, &x);
    struct ncplane* ncp = ncplane_new(nc_, 2, 2, y, ncols - 3, nullptr);
    REQUIRE(ncp);
    REQUIRE(0 == cells_rounded_box(ncp, 0, 0, &ul, &ur, &ll, &lr, &hl, &vl));
    CHECK(0 == ncplane_box(ncp, &ul, &ur, &ll, &lr, &hl, &vl, y + 1, x + 1, 0));
    CHECK(0 == notcurses_render(nc_));
    // FIXME verify with ncplane_at_cursor()
    CHECK(0 == ncplane_destroy(ncp));
  }
  SUBCASE("MoveToLowerRight") {
    int ncols, nrows;
    ncplane_dim_yx(n_, &nrows, &ncols);
    cell ul{}, ll{}, lr{}, ur{}, hl{}, vl{};
    int y, x;
    ncplane_yx(n_, &y, &x);
    struct ncplane* ncp = ncplane_new(nc_, 2, 2, y, x, nullptr);
    REQUIRE(ncp);
    REQUIRE(0 == cells_rounded_box(ncp, 0, 0, &ul, &ur, &ll, &lr, &hl, &vl));
    CHECK(0 == ncplane_box(ncp, &ul, &ur, &ll, &lr, &hl, &vl, y + 1, x + 1, 0));
    CHECK(0 == notcurses_render(nc_));
    CHECK(0 == ncplane_move_yx(ncp, nrows - 3, ncols - 3));
    CHECK(0 == notcurses_render(nc_));
    CHECK(0 == ncplane_destroy(ncp));
    // FIXME verify with ncplane_at_cursor()
  }

  // Placing a wide char to the immediate left of any other char ought obliterate
  // that cell.
  SUBCASE("WideCharAnnihilatesRight") {
    const char* w = "\xf0\x9f\x90\xb8"; // U+1F438 FROG FACE
    const char* wbashed = "\xf0\x9f\xa6\x82"; // U+1F982 SCORPION
    const char bashed = 'X';
    int sbytes = 0;
    CHECK(0 < ncplane_putegc_yx(n_, 0, 1, wbashed, 0, 0, &sbytes));
    CHECK(0 < ncplane_putsimple_yx(n_, 1, 1, bashed));
    int x, y;
    ncplane_cursor_yx(n_, &y, &x);
    CHECK(1 == y);
    CHECK(2 == x);
    CHECK(0 < ncplane_putegc_yx(n_, 0, 0, w, 0, 0, &sbytes));
    CHECK(0 < ncplane_putegc_yx(n_, 1, 0, w, 0, 0, &sbytes));
    cell c = CELL_TRIVIAL_INITIALIZER;
    ncplane_at_yx(n_, 0, 0, &c);
    const char* wres = extended_gcluster(n_, &c);
    CHECK(0 == strcmp(wres, "\xf0\x9f\x90\xb8")); // should be frog
    ncplane_at_yx(n_, 0, 1, &c);
    CHECK(cell_double_wide_p(&c)); // should be wide
    ncplane_at_yx(n_, 0, 2, &c);
    CHECK(0 == c.gcluster); // should be nothing
    ncplane_at_yx(n_, 1, 0, &c);
    wres = extended_gcluster(n_, &c);
    CHECK(0 == strcmp(wres, "\xf0\x9f\x90\xb8")); // should be frog
    ncplane_at_yx(n_, 1, 1, &c);
    CHECK(cell_double_wide_p(&c)); //should be wide
    ncplane_at_yx(n_, 0, 2, &c);
    CHECK(0 == c.gcluster);
    CHECK(0 == notcurses_render(nc_)); // should be nothing
  }

  // Placing a wide char on the right half of a wide char ought obliterate the
  // original wide char.
  SUBCASE("WideCharAnnihilatesWideLeft") {
    const char* w = "\xf0\x9f\x90\x8d";
    const char* wbashed = "\xf0\x9f\xa6\x82";
    int sbytes = 0;
    CHECK(0 < ncplane_putegc_yx(n_, 0, 0, wbashed, 0, 0, &sbytes));
    CHECK(0 < ncplane_putegc_yx(n_, 0, 1, w, 0, 0, &sbytes));
    int x, y;
    ncplane_cursor_yx(n_, &y, &x);
    CHECK(0 == y);
    CHECK(3 == x);
    cell c = CELL_TRIVIAL_INITIALIZER;
    ncplane_at_yx(n_, 0, 0, &c);
    CHECK(0 == c.gcluster); // should be nothing
    ncplane_at_yx(n_, 0, 1, &c);
    const char* wres = extended_gcluster(n_, &c);
    CHECK(0 == strcmp(wres, "\xf0\x9f\x90\x8d")); // should be snake
    ncplane_at_yx(n_, 0, 2, &c);
    CHECK(cell_double_wide_p(&c)); // should be wide
    CHECK(0 == notcurses_render(nc_));
  }

  // Placing a normal char on either half of a wide char ought obliterate
  // the original wide char.
  SUBCASE("WideCharsAnnihilated") {
    const char cc = 'X';
    const char* wbashedl = "\xf0\x9f\x90\x8d";
    const char* wbashedr = "\xf0\x9f\xa6\x82";
    int sbytes = 0;
    CHECK(0 < ncplane_putegc_yx(n_, 0, 0, wbashedl, 0, 0, &sbytes));
    CHECK(0 < ncplane_putegc_yx(n_, 0, 2, wbashedr, 0, 0, &sbytes));
    CHECK(1 == ncplane_putsimple_yx(n_, 0, 1, cc));
    CHECK(1 == ncplane_putsimple_yx(n_, 0, 2, cc));
    int x, y;
    ncplane_cursor_yx(n_, &y, &x);
    CHECK(0 == y);
    CHECK(3 == x);
    cell c = CELL_TRIVIAL_INITIALIZER;
    ncplane_at_yx(n_, 0, 0, &c);
    CHECK(0 == c.gcluster); // should be nothing
    ncplane_at_yx(n_, 0, 1, &c);
    CHECK(cc == c.gcluster); // should be 'X'
    ncplane_at_yx(n_, 0, 2, &c);
    CHECK(cc == c.gcluster); // should be 'X"
    ncplane_at_yx(n_, 0, 3, &c);
    CHECK(0 == c.gcluster); // should be nothing
    CHECK(0 == notcurses_render(nc_));
  }

  // But placing something to the immediate right of any glyph, that is not a
  // problem. Ensure it is so.
  SUBCASE("AdjacentCharsSafe") {
    const char cc = 'X';
    const char* wsafel = "\xf0\x9f\x90\x8d";
    const char* wsafer = "\xf0\x9f\xa6\x82";
    int sbytes = 0;
    CHECK(0 < ncplane_putegc_yx(n_, 0, 0, wsafel, 0, 0, &sbytes));
    CHECK(0 < ncplane_putegc_yx(n_, 0, 3, wsafer, 0, 0, &sbytes));
    CHECK(1 == ncplane_putsimple_yx(n_, 0, 2, cc));
    int x, y;
    ncplane_cursor_yx(n_, &y, &x);
    CHECK(0 == y);
    CHECK(3 == x);
    cell c = CELL_TRIVIAL_INITIALIZER;
    ncplane_at_yx(n_, 0, 0, &c);
    const char* wres = extended_gcluster(n_, &c);
    CHECK(0 == strcmp(wres, "\xf0\x9f\x90\x8d")); // should be snake
    ncplane_at_yx(n_, 0, 1, &c);
    CHECK(cell_double_wide_p(&c)); // should be snake
    ncplane_at_yx(n_, 0, 2, &c);
    CHECK(cc == c.gcluster); // should be 'X'
    ncplane_at_yx(n_, 0, 3, &c);
    wres = extended_gcluster(n_, &c);
    CHECK(0 == strcmp(wres, "\xf0\x9f\xa6\x82")); // should be scorpion
    ncplane_at_yx(n_, 0, 4, &c);
    CHECK(cell_double_wide_p(&c)); // should be scorpion
    CHECK(0 == notcurses_render(nc_));
  }

  CHECK(0 == notcurses_stop(nc_));
  CHECK(0 == fclose(outfp_));

}