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@mbostock
Forked from mbostock/.block
Last active Mar 6, 2017
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Rotating Transverse Mercator
license: gpl-3.0
height: 960
<!DOCTYPE html>
<meta charset="utf-8">
<canvas width="960" height="960"></canvas>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script src="https://unpkg.com/topojson-client@2"></script>
<script>
var width = 960,
height = 960,
speed = 1e-2;
var projection = d3.geoTransverseMercator()
.scale((width + 1) / 2 / Math.PI)
.translate([width / 2, height / 2])
.precision(0.5);
var canvas = d3.select("canvas"),
context = canvas.node().getContext("2d"),
path = d3.geoPath(projection, context);
d3.json("https://unpkg.com/world-atlas@1/world/110m.json", function(error, topo) {
if (error) throw error;
var graticule = d3.geoGraticule10(),
land = topojson.feature(topo, topo.objects.land),
borders = topojson.mesh(topo, topo.objects.countries, function(a, b) { return a !== b; });
d3.timer(function(elapsed) {
projection.rotate([speed * elapsed, 0]);
context.clearRect(0, 0, width, height);
context.beginPath();
path(land);
context.fillStyle = "#222";
context.fill();
context.beginPath();
path(borders);
context.lineWidth = 0.5;
context.strokeStyle = "#fff";
context.stroke();
context.beginPath();
path(graticule);
context.lineWidth = 0.5;
context.strokeStyle = "rgba(119,119,119,.5)";
context.stroke();
});
});
</script>
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