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@wboykinm
Forked from mbostock/.block
Last active August 30, 2016 15:52
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Duotone map tiles w/ an SVG transform
license: gpl-3.0
<!DOCTYPE html>
<meta charset="utf-8">
<style>
body {
margin: 0;
}
path {
fill: none;
stroke: red;
stroke-linejoin: round;
stroke-width: 1.5px;
}
</style>
<svg>
<defs>
<filter id="duotone" color-interpolation-filters="sRGB">
<feColorMatrix type="saturate" values="0" />
<feColorMatrix type="matrix" />
</filter>
</defs>
</svg>
<script src="//d3js.org/d3.v4.0.0-rc.1.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 pi = Math.PI,
tau = 2 * pi;
var width = Math.max(960, window.innerWidth),
height = Math.max(500, window.innerHeight);
// Initialize the projection to fit the world in a 1×1 square centered at the origin.
var projection = d3.geoMercator()
.scale(1 / tau)
.translate([0, 0]);
var path = d3.geoPath()
.projection(projection);
var tile = d3.tile()
.size([width, height]);
var zoom = d3.zoom()
.scaleExtent([1 << 11, 1 << 14])
.on("zoom", zoomed);
var svg = d3.select("svg")
.attr("width", width)
.attr("height", height);
var raster = svg.append("g");
// Compute the projected initial center.
var center = projection([-77.03687,38.8919]);
// 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 << 22)
.translate(-center[0], -center[1]));
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]);
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 "http://" + "abc"[d[1] % 3] + ".tile.stamen.com/toner/" + d[2] + "/" + d[0] + "/" + d[1] + ".png"; })
.attr("x", function(d) { return d[0] * 256; })
.attr("y", function(d) { return d[1] * 256; })
.attr("width", 256)
.attr("height", 256)
.attr("filter","url(#duotone)");
}
function type(d) {
return {
type: "Feature",
properties: {name: d.description, state: d.name},
geometry: {type: "Point", coordinates: [+d.longitude, +d.latitude]}
};
}
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 + ")";
}
var filter = d3.select("feColorMatrix:last-child"),
matrix = [
[ 0, 0, 0, 0, 0 ],
[ 0, 0, 0, 0, 0 ],
[ 0, 0, 0, 0, 0 ],
[ 0, 0, 0, 1, 0 ],
];
d3.timer(function(t){
var bg,
fg;
t = t % 7500 / 7500;
if (t > 0.5) t = 1 - t;
fg = d3.rgb(d3.interpolateWarm(t)).darker(0.75);
bg = d3.rgb(d3.interpolateCool(1 - t)).brighter(0.1);
["r", "g", "b"].forEach(function(d, i){
matrix[i][i] = (bg[d] - fg[d]) / 256;
matrix[i][4] = fg[d] / 256;
});
filter.attr("values", matrix.join(" "));
});
</script>
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