diff -r efd9c589177a -r c0b4a8b5a012 toolkit/javascript/d3/examples/voroboids/voroboids.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/examples/voroboids/voroboids.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,65 @@
+var w = 960,
+    h = 500,
+    mouse = [null, null],
+    fill = d3.scale.linear().domain([0, 1e4]).range(["brown", "steelblue"]);
+
+// Initialise boids.
+var boids = d3.range(100).map(function() {
+  return boid()
+      .position([Math.random() * w, Math.random() * h])
+      .velocity([Math.random() * 2 - 1, Math.random() * 2 - 1])
+      .gravityCenter(mouse);
+});
+
+// Compute initial positions.
+var vertices = boids.map(function(boid) {
+  return boid(boids);
+});
+
+d3.select(window).on("blur", nullGravity);
+
+var svg = d3.select("#vis")
+  .append("svg:svg")
+    .attr("width", w)
+    .attr("height", h)
+    .attr("class", "PiYG")
+    .on("mousemove", function() {
+      var m = d3.svg.mouse(this);
+      mouse[0] = m[0];
+      mouse[1] = m[1];
+    })
+    .on("mouseout", nullGravity);
+
+svg.selectAll("path")
+    .data(d3.geom.voronoi(vertices))
+  .enter().append("svg:path")
+    .attr("class", function(d, i) { return i ? "q" + (i % 9) + "-9" : null; })
+    .attr("d", function(d) { return "M" + d.join("L") + "Z"; });
+
+svg.selectAll("circle")
+    .data(vertices)
+  .enter().append("svg:circle")
+    .attr("transform", function(d) { return "translate(" + d + ")"; })
+    .attr("r", 2);
+
+d3.timer(function() {
+  // Update boid positions.
+  boids.forEach(function(boid, i) {
+    vertices[i] = boid(boids);
+  });
+
+  // Update circle positions.
+  svg.selectAll("circle")
+      .data(vertices)
+      .attr("transform", function(d) { return "translate(" + d + ")"; });
+
+  // Update voronoi diagram.
+  svg.selectAll("path")
+      .data(d3.geom.voronoi(vertices))
+      .attr("d", function(d) { return "M" + d.join("L") + "Z"; })
+      .style("fill", function(d) { return fill((d3.geom.polygon(d).area())); });
+});
+
+function nullGravity() {
+  mouse[0] = mouse[1] = null;
+}