Function intersectRule

docs/tests/v2/es6/js/sanddance.js:98661–98667

(item, box)

}

function intersectRule(item, box) {
  const x = item.x || 0,
        y = item.y || 0,
        x2 = item.x2 != null ? item.x2 : x,
        y2 = item.y2 != null ? item.y2 : y;
  return intersectBoxLine(box, x, y, x2, y2);
}

function intersectBoxLine(box, x, y, u, v) {
  const {