D3 Examples - Globe pan

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<html>
<head>
  <title>D3 in Action Chapter 7 - Example 5</title>
  <meta charset="utf-8" />
<script src="https://d3js.org/d3.v3.min.js" type="text/JavaScript"></script>
<script src="https://d3js.org/d3.geo.projection.v0.min.js" type="text/JavaScript"></script>
<script src="https://d3js.org/queue.v1.min.js" type="text/JavaScript"></script>
<script src="https://d3js.org/colorbrewer.v1.min.js" type="text/JavaScript"></script>
</head>
<style>
  svg {
    border: 1px solid gray;
  }
  
  .countries {
    fill: red;
    fill-opacity: .5;
    stroke: black;
    stroke-width: 1px;
  }
​
</style>
<body>
​
<div id="viz">
</div>
<div id="controls" />
</body>
  <footer>
    
<script>
  
  var width = 800;
  var height = 500;
  d3.select("#viz").append("svg").attr("width", width).attr("height", height);
  
     queue()
    .defer(d3.json, "world.geojson")
    .defer(d3.csv, "cities.csv")
    .await(function(error, file1, file2) { createMap(file1, file2); });
    
  function createMap(countries, cities) {
    expData = countries;
    projection = d3.geo.orthographic()
    .scale((Math.min(width,height) / 2))
    .translate([width / 2, height / 2])
    .clipAngle(90);
    geoPath = d3.geo.path().projection(projection);
    
    var mapZoom = d3.behavior.zoom().translate(projection.translate()).scale(projection.scale()).on("zoom", zoomed);
    
    d3.select("svg").call(mapZoom);
    
    var rotateScale = d3.scale.linear()
    .domain([0, width])
    .range([0, 180]);
    var currentRotation = projection.rotate();
    
    d3.select("svg").on("mousedown", startRotating).on("mouseup", stopRotating);
    
    function startRotating() {
      var pStart = d3.mouse(this);
      var currentLat = (currentRotation[1] + 360) % 360;
      var xFactor = (currentLat > 90 && currentLat < 270) ? -1.0 : 1.0;
      d3.select("svg").on("mousemove", function() {
        var p = d3.mouse(this);
        projection.rotate([
          currentRotation[0] + xFactor * (rotateScale(p[0] - pStart[0])),
          currentRotation[1] + rotateScale(pStart[1] - p[1])]);
        zoomed();
      });
    }
​
    function stopRotating() {
      currentRotation = projection.rotate();
      console.log(currentRotation);
      d3.select("svg").on("mousemove", null);
        }    
    function zoomed() {
      var currentRotate = projection.rotate()[0];
      projection.scale(mapZoom.scale());
      d3.selectAll("path.graticule").attr("d", geoPath);
      d3.selectAll("path.countries").attr("d", geoPath);
    }
    
    function zoomButton(zoomDirection) {
      if (zoomDirection == "in") {
        var newZoom = mapZoom.scale() * 1.5;
        var newX = ((mapZoom.translate()[0] - (width / 2)) * 1.5) + width / 2;
        var newY = ((mapZoom.translate()[1] - (height / 2)) * 1.5) + height / 2;
      }
      else if (zoomDirection == "out") {
        var newZoom = mapZoom.scale() * .75;
        var newX = ((mapZoom.translate()[0] - (width / 2)) * .75) + width / 2;
        var newY = ((mapZoom.translate()[1] - (height / 2)) * .75) + height / 2;    
      }
​
      mapZoom.scale(newZoom).translate([newX,newY])
      zoomed();
    }
}
​
</script>
  </footer>
​
</html>
​
    