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@curran
Last active July 2, 2016 07:45
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Raster & Vector 4.0
license: gpl-3.0
<!DOCTYPE html>
<meta charset="utf-8">
<style>
body {
margin: 0;
}
path {
fill: none;
stroke: red;
stroke-linejoin: round;
}
</style>
<body>
<script src="//d3js.org/d3.v4.0.0-alpha.50.min.js"></script>
<script src="//d3js.org/d3-tile.v0.0.min.js"></script>
<script src="//d3js.org/topojson.v1.min.js"></script>
<script>
var width = Math.max(960, window.innerWidth),
height = Math.max(500, window.innerHeight);
var tile = d3.tile()
.size([width, height]);
var projection = d3.geoMercator()
.scale((1 << 12) / 2 / Math.PI)
.translate([width / 2, height / 2]);
var center = projection([-100, 40]);
var path = d3.geoPath()
.projection(projection);
var zoom = d3.zoom()
.scaleExtent([1 << 11, 1 << 14])
.on("zoom", zoomed);
var initialTransform = d3.zoomIdentity
.translate(width - center[0], height - center[1])
.scale(projection.scale() * 2 * Math.PI)
// With the center computed, now adjust the projection such that
// it uses the zoom behavior’s translate and scale.
projection
.scale(1 / 2 / Math.PI)
.translate([0, 0]);
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height);
var raster = svg.append("g");
var vector = svg.append("path");
d3.json("https://gist.githubusercontent.com/mbostock/4090846/raw/d534aba169207548a8a3d670c9c2cc719ff05c47/us.json", function(error, us) {
if (error) throw error;
svg.call(zoom).call(zoom.transform, initialTransform);
vector.attr("d", path(topojson.mesh(us, us.objects.counties)));
});
function zoomed() {
var transform = d3.event.transform;
var tiles = tile
.scale(transform.k)
.translate([transform.x, transform.y])
();
vector
.attr("transform", transform)
.style("stroke-width", 1 / transform.k);
var image = raster
.attr("transform", "scale(" + tiles.scale + ")translate(" + tiles.translate + ")")
.selectAll("image")
.data(tiles, function(d) { return d; });
image.exit()
.remove();
image.enter().append("image")
.attr("xlink:href", function(d) { return "http://" + ["a", "b", "c"][Math.random() * 3 | 0] + ".tile.openstreetmap.org/" + d[2] + "/" + d[0] + "/" + d[1] + ".png"; })
.attr("width", 1)
.attr("height", 1)
.attr("x", function(d) { return d[0]; })
.attr("y", function(d) { return d[1]; });
}
</script>
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