package.src.layout.bundle.js Maven / Gradle / Ivy
import "layout";
// Implements hierarchical edge bundling using Holten's algorithm. For each
// input link, a path is computed that travels through the tree, up the parent
// hierarchy to the least common ancestor, and then back down to the destination
// node. Each path is simply an array of nodes.
d3.layout.bundle = function() {
return function(links) {
var paths = [],
i = -1,
n = links.length;
while (++i < n) paths.push(d3_layout_bundlePath(links[i]));
return paths;
};
};
function d3_layout_bundlePath(link) {
var start = link.source,
end = link.target,
lca = d3_layout_bundleLeastCommonAncestor(start, end),
points = [start];
while (start !== lca) {
start = start.parent;
points.push(start);
}
var k = points.length;
while (end !== lca) {
points.splice(k, 0, end);
end = end.parent;
}
return points;
}
function d3_layout_bundleAncestors(node) {
var ancestors = [],
parent = node.parent;
while (parent != null) {
ancestors.push(node);
node = parent;
parent = parent.parent;
}
ancestors.push(node);
return ancestors;
}
function d3_layout_bundleLeastCommonAncestor(a, b) {
if (a === b) return a;
var aNodes = d3_layout_bundleAncestors(a),
bNodes = d3_layout_bundleAncestors(b),
aNode = aNodes.pop(),
bNode = bNodes.pop(),
sharedNode = null;
while (aNode === bNode) {
sharedNode = aNode;
aNode = aNodes.pop();
bNode = bNodes.pop();
}
return sharedNode;
}