For Alex firstcollision

_.md

[ Launch: firstcollision ] 80a222f221a4cbefb326 by ryanmedlin
[ Launch: firstcollision ] d4d9993ed18e1ae24584 by omniwired

config.json

{"description":"For Alex firstcollision","endpoint":"","display":"svg","public":true,"require":[],"fileconfigs":{"inlet.js":{"default":true,"vim":false,"emacs":false,"fontSize":12},"_.md":{"default":true,"vim":false,"emacs":false,"fontSize":12},"config.json":{"default":true,"vim":false,"emacs":false,"fontSize":12}},"fullscreen":false,"play":false,"loop":false,"restart":false,"autoinit":true,"pause":true,"loop_type":"pingpong","bv":false,"nclones":15,"clone_opacity":0.4,"duration":3000,"ease":"linear","dt":0.01,"ajax-caching":true,"thumbnail":"http://i.imgur.com/OLeLXr9.png"}

inlet.js

function forced (gravity) {

  var w = 1280,
      h = 800;

  var nodes = d3.range(200).map(function() { return {radius: Math.random() * 6.2 + 5}; }),
      color = d3.scale
  				.linear()
  .range(['#000', '#ff70c8'])

  var force = d3.layout.force()
      .gravity(gravity)
      .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").append("svg:svg")
      .attr("width", w)
      .attr("height", h);

  var a = svg.selectAll("circle")
      .data(nodes.slice(1))
    .enter().append("svg:circle")
        .transition()
  .duration(6873).attr('r',0)
      .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.mouse(this);
    root.px = p1[0];
    root.py = p1[1];
    force.resume();
  });

   svg.on("click", function() {
    var p1 = d3.mouse(this);
    // force.stop();
    // root.radius = 100;
    nodes.push(nodes[0]);
  });
}

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;
  };
}

forced(0.10);