Calculate levelDistance to keep nodes from overlapping

[Daniel Schaefer]

I am working on a RGraph. I am having trouble trying to compute the right levelDistance for both the nodes and the background canvas so that my nodes and their labels do not overlap. If I knew the maximum arc length of a given node, how would I go about computing a good levelDistance to accomplish this? I would obviously need to loadJSON first, so that each node gets assigned a _treeAngularWidth. With that value, I may be able to find the levelDistance I'm looking for. Assuming I'm able to do that, how do I change the initial values of levelDistance for the nodes and the background canvas?

[Daniel Schaefer]

Maybe not the best of most efficient solution, but here is what I came up with. Suggestions are welcome...

function addBackground(graph) {

    graph.canvas.canvases[1].clear();

    graph.canvas.canvases[1].opt.levelDistance = graph.config.levelDistance;

    graph.canvas.canvases[1].opt.numberOfCircles = graph.config.background.numberOfCircles;

    graph.canvas.scale(1, 1);

    return graph;

}

    //Calculate a proper levelDistance so that the nodes don't overlap

    var minSpan = Math.PI * 2;

    var maxDepth = 0;

    rgraph.graph.eachNode(function(n) {

        if (n._depth == 1 && n.endData.$span < minSpan) {

            minSpan = n.endData.$span;

        }

        if (n._depth > maxDepth) {

            maxDepth = n._depth;

        }

    });

    if (75 / minSpan > rgraph.config.levelDistance) {

        rgraph.config.levelDistance = 75 / minSpan;

        //TODO Calculate a proper initial zoomLevel to fit all nodes

        rgraph.compute('end');

    }

    rgraph.config.background.levelDistance = rgraph.config.levelDistance;

    rgraph.config.background.numberOfCircles = maxDepth;

    rgaph = addBackground(rgraph);