Map Pan & Zoom II

This example uses d3.behavior.zoom with a dynamic projection for map panning and zooming. This approach is slower than using a transform or transforming pre-projected geometry because it requires reprojecting whenever the zoom changes.

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

svg {
  background: #eee;
}

.sphere {
  fill: #fff;
}

.land {
  fill: #000;
}

.boundary {
  fill: none;
  stroke: #fff;
  stroke-linejoin: round;
  stroke-linecap: round;
  vector-effect: non-scaling-stroke;
}

.overlay {
  fill: none;
  pointer-events: all;
}

</style>
<script src="//d3js.org/d3.v3.min.js"></script>
<script src="//d3js.org/topojson.v1.min.js"></script>
<body>
<script>

var width = 960,
    height = 960,
    scale0 = (width - 1) / 2 / Math.PI;

var projection = d3.geo.mercator();

var zoom = d3.behavior.zoom()
    .translate([width / 2, height / 2])
    .scale(scale0)
    .scaleExtent([scale0, 8 * scale0])
    .on("zoom", zoomed);

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

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

var g = svg.append("g");

svg.append("rect")
    .attr("class", "overlay")
    .attr("width", width)
    .attr("height", height);

svg
    .call(zoom)
    .call(zoom.event);

d3.json("/../../data/world-110m.json", function(error, world) {
  if (error) throw error;

g.append("path")
      .datum({type: "Sphere"})
      .attr("class", "sphere")
      .attr("d", path);

g.append("path")
      .datum(topojson.merge(world, world.objects.countries.geometries))
      .attr("class", "land")
      .attr("d", path);

g.append("path")
      .datum(topojson.mesh(world, world.objects.countries, function(a, b) { return a !== b; }))
      .attr("class", "boundary")
      .attr("d", path);
});

function zoomed() {
  projection
      .translate(zoom.translate())
      .scale(zoom.scale());

g.selectAll("path")
      .attr("d", path);
}

d3.select(self.frameElement).style("height", height + "px");

</script>

Changed /mbostock/raw/4090846/world-110m.json to a local referenece

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

https://d3js.org/topojson.v1.min.js