scope renderLineCompedSingleLevels_raw.

static byte[][] renderLineCompedSingleLevels_raw(LineCompedSingle<Char> lc) {
  int n = lcLength(lc);
  
  // each byte is the character's "color"
  // (0 for empty, 1 for color one, 2 for color two)
  L<byte[]> rows = new AutoCreateList<>(() -> new byte[n]);
  fill(lc, rows, 0, 0, lc.main, 1);
  ret toArray(rows, byte[].class);
}
  
// returns new x
static int #fill(LineCompedSingle<Char> lc, L<byte[]> rows, int x, int y, L<Int> symbols, int color) {
  //printVars_str fill(+x, +y, +symbols, +color);
  for (int idx : symbols) {
    if (idx < l(lc.literals)) {
      rows.get(y)[x] = (byte) color;
      x++;
    } else {
      int newX = fill(lc, rows, x, y+1, intPairToList(lc.getPair(idx)), color);
      while (x < newX) rows.get(y)[x++] = (byte) color;
      color = 3-color;
    }
  }
  ret x;
}

end scope

Began life as a copy of #1031198