RailwayRouteOptimization/scripts/lib/hull/intersect.js

function ccw(x1, y1, x2, y2, x3, y3) {           
    var cw = ((y3 - y1) * (x2 - x1)) - ((y2 - y1) * (x3 - x1));
    return cw > 0 ? true : cw < 0 ? false : true; // colinear
}

function intersect(seg1, seg2) {
  var x1 = seg1[0][0], y1 = seg1[0][1],
      x2 = seg1[1][0], y2 = seg1[1][1],
      x3 = seg2[0][0], y3 = seg2[0][1],
      x4 = seg2[1][0], y4 = seg2[1][1];
    return ccw(x1, y1, x3, y3, x4, y4) !== ccw(x2, y2, x3, y3, x4, y4) && ccw(x1, y1, x2, y2, x3, y3) !== ccw(x1, y1, x2, y2, x4, y4);
}

//module.exports = intersect;