Function corner

explainshell/web/static/js/d3.v3.js:2759–2761

(p, direction)

      return clip;
    };
    function corner(p, direction) {
      return Math.abs(p[0] - x0) < ε ? direction > 0 ? 0 : 3 : Math.abs(p[0] - x1) < ε ? direction > 0 ? 2 : 1 : Math.abs(p[1] - y0) < ε ? direction > 0 ? 1 : 0 : direction > 0 ? 3 : 2;
    }
    function compare(a, b) {
      return comparePoints(a.point, b.point);
    }