Another Inlet

config.json

{"description":"Another Inlet","endpoint":"","display":"svg","public":true,"require":[],"tab":"edit","display_percent":0.7,"play":false,"loop":false,"restart":false,"autoinit":true,"pause":true,"loop_type":"period","bv":false,"nclones":15,"clone_opacity":0.4,"duration":3000,"ease":"linear","dt":0.01}

inlet.js

var w = 700,
    h = 700;

var nodes = d3.range(5).map(
      function() 
      { 
        return {
          radius: Math.random() * 100 + 50
        }; 
      }
	),
    color = d3.scale.category10();

var force = d3.layout.force()
    .gravity(0.1)
    .charge(
      function(d, i) 
      { 
        return i ? 0 : -2000; 
      }
    )
    .nodes(nodes)
    .size([w, h]);

var root = nodes[0];
root.radius = 0;
root.fixed = true;

force.start();

var svg = d3.select("svg");

svg.selectAll("circle")
    .data(nodes.slice(1))
  .enter().append("svg:circle")
    .attr("r", function(d) { return d.radius - 2; })
    .style("fill", function(d, i) { return color(i % 3); });

force.on("tick", function(e) {
  var q = d3.geom.quadtree(nodes),
      i = 0,
      n = nodes.length;

  while (++i < n) {
    q.visit(collide(nodes[i]));
  }

  svg.selectAll("circle")
      .attr("cx", function(d) { return d.x; })
      .attr("cy", function(d) { return d.y; });
});

/*
svg.on("mousemove", function() {
  var p1 = d3.svg.mouse(this);
  root.px = p1[0];
  root.py = p1[1];
  force.resume();
});
*/

function collide(node) {
  var r = node.radius + 16,
      nx1 = node.x - r,
      nx2 = node.x + r,
      ny1 = node.y - r,
      ny2 = node.y + r;
  return function(quad, x1, y1, x2, y2) {
    if (quad.point && (quad.point !== node)) {
      var x = node.x - quad.point.x,
          y = node.y - quad.point.y,
          l = Math.sqrt(x * x + y * y),
          r = node.radius + quad.point.radius;
      if (l < r) {
        l = (l - r) / l * .5;
        node.x -= x *= l;
        node.y -= y *= l;
        quad.point.x += x;
        quad.point.y += y;
      }
    }
    return x1 > nx2
        || x2 < nx1
        || y1 > ny2
        || y2 < ny1;
  };
}