Adaptive Composite Map Projection with d3

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">
  <title>Adaptive Composite Map Projection (Lite)</title>
  <style>
  body {
    background: #fcfcfa;
    height: 500px;
    position: relative;
    width: 960px;
  }
  .stroke {
    fill: none;
    stroke: #000;
    stroke-width: 3px;
  }
  .fill {
    fill: #000;
  }
  .graticule {
    fill: none;
    stroke: #fff;
    stroke-width: .5px;
    stroke-opacity: .5;
  }
  .land {
    fill: #fff;
    stroke:#777;
    stroke-width:.75px;
  }
  .boundary {
    fill: none;
    stroke: #fff;
    stroke-width: .5px;
  }
  </style>
</head>
<body>
  <script src="https://d3js.org/d3.v3.min.js"></script>
  <script src="https://d3js.org/d3.geo.projection.v0.min.js"></script>
  <script src="https://d3js.org/topojson.v1.min.js"></script>
  <script type="text/javascript">

function pickProjection(scale, coords) {
    if (scale <= 1.5) {
      d3.select("#proj").text("Hammer");
      currentProj = "hammer";
      return d3.geo.hammer()
         .coefficient(2)
         .precision(0.3)
         .scale(scale * 100)
         .rotate([coords[0],0]);

} else if (scale <= 2.0) {
      d3.select("#proj").text("Modified Hammer");
      currentProj = "hammer";
      return d3.geo.hammer()
         .coefficient(2.0 - (scale-1.5) * 2.0)
         .precision(0.3)
         .scale(scale * 100)
         .rotate([coords[0],0]);

} else if (scale <= 6.0) {
      d3.select("#proj").text("Lambert azimuthal");
      currentProj = "lambert";
      return d3.geo.azimuthalEqualArea()
         .scale(scale * 100)
         .precision(0.3)
         .clipAngle(180 - 1e-3)
         .rotate(coords);

} else if (scale <= 12) {
        d3.select("#proj").text("Albers");
        currentProj = "albers";
        coords = (coords[0] == 0) ? [0.01, 0.01] : coords;
        return d3.geo.albers()
          .rotate([coords[0], 0])
          .center([0, -coords[1]])
          .parallels([ -coords[1] - scale, -coords[1] + scale])
          .scale(scale * 100)
          .translate([width / 2, height / 2])
          .precision(.1);

} else {
      d3.select("#proj").text("Mercator");
      return d3.geo.mercator()
         .scale(scale * 95)
         .translate([width / 2, height / 2])
         .rotate([coords[0],0])
         .center([0, -coords[1]]);
    }
  }

var width = 960,
      height = 500,
      scale = 1,
      currentProj;

var rotate = [0,0];

var projection = pickProjection(1, [0,0]);

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

var graticule = d3.geo.graticule();

var m0,
      o0;

rotate = [-o1[0], -o1[1]];
        scale = (d3.event.scale >= 1) ? d3.event.scale : 1;
        projection = pickProjection(scale, rotate);
        d3.selectAll("path").attr("d", path.projection(projection));

});

var svg = d3.select("body").append("svg")
      .attr("width", width)
      .attr("height", height)
      .call(zoom);
      
  svg.append("defs").append("path")
      .datum({type: "Sphere"})
      .attr("id", "sphere")
      .attr("d", path);

svg.append("use")
      .attr("class", "stroke")
      .attr("xlink:href", "#sphere");

svg.append("use")
      .attr("class", "fill")
      .attr("xlink:href", "#sphere");

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

d3.json("countries_1e5.json", function(error, data) {
    svg.insert("path", ".graticule")
        .datum(topojson.feature(data, data.objects.countries))
        .attr("class", "land")
        .attr("d", path);

d3.select("body").append("text")
      .attr("id", "info");
    d3.select("body").append("text")
      .attr("id", "proj");
  });
</script>
</body>
</html>

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

Modified http://d3js.org/d3.geo.projection.v0.min.js to a secure url

Modified http://d3js.org/topojson.v1.min.js to a secure url

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

https://d3js.org/d3.geo.projection.v0.min.js

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