World Boundaries TopoJSON

A demo of Mike Bostock’s TopoJSON using states & provinces boundaries from Natural Earth.

With simplification turned on (-s 100), this reduces the original 57MB GeoJSON file to a mere 515KB!

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

path {
  fill: none;
  stroke: #000;
}

.graticule {
  fill: none;
  stroke: #ccc;
  stroke-width: .5px;
}

.foreground {
  fill: none;
  stroke: #333;
  stroke-width: 1.5px;
}

</style>
<body>
<script src="https://d3js.org/d3.v3.min.js"></script>
<script src="topojson.js"></script>
<script>

var width = 960,
    height = 500;

var projection = d3.geo.orthographic()
    .scale(250)
    .clipAngle(90);

var path = d3.geo.path()
    .projection(projection);

var graticule = d3.geo.graticule();

var λ = d3.scale.linear()
    .domain([0, width])
    .range([-180, 180]);

var φ = d3.scale.linear()
    .domain([0, height])
    .range([90, -90]);

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

svg.on("mousemove", function() {
  var p = d3.mouse(this);
  projection.rotate([λ(p[0]), φ(p[1])]);
  svg.selectAll("path:not(.foreground)").attr("d", path);
});

svg.append("path")
    .attr("class", "graticule")
    .datum(graticule)
    .attr("d", path);

svg.append("path")
    .datum(graticule.outline)
    .attr("class", "foreground")
    .attr("d", path);

d3.json("readme-world-admin1.json", function(error, topology) {
  svg.append("path")
      .datum(topojson.mesh(topology))
      .attr("d", path);
});

</script>

Modified http://d3js.org/d3.v3.min.js to a secure url

https://d3js.org/d3.v3.min.js