@thi.ng/grid-iterators/diagonal.js

2D grid and shape iterators w/ multiple orderings

import { __opts } from "./utils.js";
function* diagonal2d(opts) {
  const { cols, rows, tx } = __opts(opts);
  const num = cols * rows - 1;
  for (let x = 0, y = 0, nx = 1, ny = 0, i = 0; i <= num; i++) {
    yield tx(x, y);
    if (i !== num) {
      do {
        if (y === ny) {
          y = 0;
          x = nx;
          ny++;
          nx++;
        } else {
          x--;
          y++;
        }
      } while (y >= rows || x >= cols);
    }
  }
}
export {
  diagonal2d
};