// source https://jsbin.com/widajoy

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

#states {
  fill: none;
  stroke: black;
  stroke-width: 1.5px;
  stroke-linejoin: round;
}

#quakes {
  fill: crimson;
  stroke: orange;
  fill-opacity: 0.6;
}
  
.info {
  font-family: sans-serif;
  color: #000;
  position: absolute;
  bottom: 10px;
  right: 10px;
}
  
</style>
<svg></svg>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script src="https://d3js.org/d3-tile.v0.0.min.js"></script>
<script src="https://d3js.org/topojson.v1.min.js"></script>
<script src="https://tatornator12.github.io/classes/class-09/d3-tile.js"></script>
<script>

var pi = Math.PI,
    tau = 2 * pi;
  
var width = Math.max(960, window.innerWidth),
    height = Math.max(500, window.innerHeight);

var projection = d3.geoMercator()
    .scale(1 / tau)
    .translate([0, 0]);
  
var path = d3.geoPath()
    .projection(projection);
  
var tile = d3.tile()
    .size([width, height])
    .wrap(true);
  
var zoom = d3.zoom()
    .scaleExtent([1 << 11, 1 << 14])
    .on("zoom", zoomed);
  
var svg = d3.select("svg")
    .attr("width", width)
    .attr("height", height)
    .on("mousemove", mousemoved);
  
// Add a <div> element to label the mouse position
var info = d3.select("body").append("div")
    .attr("class", "info");
  
var raster = svg.append("g");
  
var vector = svg.append("path");
  
var vector2 = svg.append("g");

var usgs = "https://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/all_week.geojson";
var url = "https://umbcvis.github.io/classes/class-03/us.json";
      
d3.queue()
  .defer(d3.json, url)
  .defer(d3.json, usgs)
  .await(ready);
  
function ready(error, us, json) {
  if (error) throw error;
    
  var quakes = json.features;
  
  // Plot the state boundaries
  vector
    .attr("id", "states")
    .datum(topojson.mesh(us, us.objects.us))
    .attr("d", path);
    
  var center = projection([-98.5, 39.5]);
  
  // Apply a zoom transform equivalent to projection.{scale,translate,center}.
  svg
      .call(zoom)
      .call(zoom.transform, d3.zoomIdentity
          .translate(width / 2, height / 2)
          .scale(1 << 12)
          .translate(-center[0], -center[1]))
  
  // Plot the earthquakes
  vector2.selectAll(".quake")
      .data(quakes)
   .enter().append("path")
      .attr("id", "quakes")
      .attr("d", path);
  
}

function zoomed() {
  var transform = d3.event.transform;

var tiles = tile
      .scale(transform.k)
      .translate([transform.x, transform.y])
      ();

projection
      .scale(transform.k / tau)
      .translate([transform.x, transform.y]);
    
  path = d3.geoPath()
     .projection(projection);
  
  d3.selectAll("path")
     .attr("d", path);
    
  var image = raster
      .attr("transform", stringify(tiles.scale, tiles.translate))
    .selectAll("image")
    .data(tiles, function(d) { return d; });

image.exit().remove();

image.enter().append("image")
      .attr("xlink:href", function(d) { return "https://" + "abc"[d[1] % 3] + ".tile.openstreetmap.org/" + d[2] + "/" + d[0] + "/" + d[1] + ".png"; })
      .attr("x", function(d) { return d.x; })
      .attr("y", function(d) { return d.y; })
      .attr("width", 256)
      .attr("height", 256);
}

function stringify(scale, translate) {
  var k = scale / 256, r = scale % 1 ? Number : Math.round;
  return "translate(" + r(translate[0] * scale) + "," + r(translate[1] * scale) + ") scale(" + k + ")";
}

function mousemoved() {
  info.text(formatLocation(projection.invert(d3.mouse(this)), projection.scale()));
}
  
// Format the text that will be displayed in the the <div> element on the map
function formatLocation(p, k) {
  var format = d3.format("." + Math.floor(Math.log(k) / 2 - 2) + "f");
  return (p[1] < 0 ? format(-p[1]) + "°S" : format(p[1]) + "°N") + " "
       + (p[0] < 0 ? format(-p[0]) + "°W" : format(p[0]) + "°E");
} 
 
</script>
<script id="jsbin-source-html" type="text/html"><!DOCTYPE html>
<meta charset="utf-8">
<style>

#states {
  fill: none;
  stroke: black;
  stroke-width: 1.5px;
  stroke-linejoin: round;
}

#quakes {
  fill: crimson;
  stroke: orange;
  fill-opacity: 0.6;
}
  
.info {
  font-family: sans-serif;
  color: #000;
  position: absolute;
  bottom: 10px;
  right: 10px;
}
  
</style>
<svg></svg>
<script src="//d3js.org/d3.v4.min.js"><\/script>
<script src="//d3js.org/d3-tile.v0.0.min.js"><\/script>
<script src="//d3js.org/topojson.v1.min.js"><\/script>
<script src="https://tatornator12.github.io/classes/class-09/d3-tile.js"><\/script>
<script>

var pi = Math.PI,
    tau = 2 * pi;
  
var width = Math.max(960, window.innerWidth),
    height = Math.max(500, window.innerHeight);

function zoomed() {
  var transform = d3.event.transform;

var tiles = tile
      .scale(transform.k)
      .translate([transform.x, transform.y])
      ();

image.exit().remove();

Modified http://d3js.org/d3.v4.min.js to a secure url

Modified http://d3js.org/d3-tile.v0.0.min.js to a secure url

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

https://d3js.org/d3.v4.min.js

https://d3js.org/d3-tile.v0.0.min.js

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

https://tatornator12.github.io/classes/class-09/d3-tile.js

https://d3js.org/d3.v4.min.js

https://d3js.org/d3-tile.v0.0.min.js

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

https://tatornator12.github.io/classes/class-09/d3-tile.js