dushmis · December 25, 2017 11:07
diff --git a/index.html b/index.html
 <!DOCTYPE html>
 <meta charset="utf-8">

 <body>
  <script src="//d3js.org/d3.v3.min.js"></script>
  <script>

    var width = window.innerWidth,
      height = window.innerHeight;

    var nodes = d3.range(100).map(function () { return { radius: Math.random() * 15 + 10 }; }),
      root = nodes[0];

    root.radius = 0;
    root.fixed = true;

    var force = d3.layout.force()
      .gravity(0.05)
      .charge(function (d, i) { return i ? 0 : -2000; })
      .nodes(nodes)
      .size([width, height]);

    force.start();

    var canvas = d3.select("body").append("canvas")
      .attr("width", width)
      .attr("height", height);

    var context = canvas.node().getContext("2d");

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

      for (i = 1; i < n; ++i) q.visit(collide(nodes[i]));

      context.clearRect(0, 0, width, height);
      context.fillStyle = "red";
      context.beginPath();
      for (i = 1; i < n; ++i) {
        d = nodes[i];
        context.moveTo(d.x, d.y);
        context.arc(d.x, d.y, d.radius, 0, 2 * Math.PI);
      }
      context.fill();
    });

    canvas.on("mousemove", function () {
      var p1 = d3.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;
      };
    }

  </script>
	<!DOCTYPE html>
	<meta charset="utf-8">

	<body>
	<script src="//d3js.org/d3.v3.min.js"></script>
	<script>

	var width = window.innerWidth,
	height = window.innerHeight;

	var nodes = d3.range(100).map(function () { return { radius: Math.random() * 15 + 10 }; }),
	root = nodes[0];

	root.radius = 0;
	root.fixed = true;

	var force = d3.layout.force()
	.gravity(0.05)
	.charge(function (d, i) { return i ? 0 : -2000; })
	.nodes(nodes)
	.size([width, height]);

	force.start();

	var canvas = d3.select("body").append("canvas")
	.attr("width", width)
	.attr("height", height);

	var context = canvas.node().getContext("2d");

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

	for (i = 1; i < n; ++i) q.visit(collide(nodes[i]));

	context.clearRect(0, 0, width, height);
	context.fillStyle = "red";
	context.beginPath();
	for (i = 1; i < n; ++i) {
	d = nodes[i];
	context.moveTo(d.x, d.y);
	context.arc(d.x, d.y, d.radius, 0, 2 * Math.PI);
	}
	context.fill();
	});

	canvas.on("mousemove", function () {
	var p1 = d3.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;
	};
	}

	</script>