what doese mean about [routePatterns] in mxEdgeStyle.js

Question

in the mxEdgeStyle.js

routePatterns: [
    [ [ 513, 2308, 2081, 2562 ], [ 513, 1090, 514, 2184, 2114, 2561 ],
        [ 513, 1090, 514, 2564, 2184, 2562 ],
        [ 513, 2308, 2561, 1090, 514, 2568, 2308 ] ],

[ [ 514, 1057, 513, 2308, 2081, 2562 ], [ 514, 2184, 2114, 2561 ],
        [ 514, 2184, 2562, 1057, 513, 2564, 2184 ],
        [ 514, 1057, 513, 2568, 2308, 2561 ] ],

[ [ 1090, 514, 1057, 513, 2308, 2081, 2562 ], [ 2114, 2561 ],
        [ 1090, 2562, 1057, 513, 2564, 2184 ],
        [ 1090, 514, 1057, 513, 2308, 2561, 2568 ] ],

[ [ 2081, 2562 ], [ 1057, 513, 1090, 514, 2184, 2114, 2561 ],
        [ 1057, 513, 1090, 514, 2184, 2562, 2564 ],
        [ 1057, 2561, 1090, 514, 2568, 2308 ] ] ],

When I want to calculate waypoint's direction, how can I choose it?

I'm new for mxgraph, thanks