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@kaezarrex kaezarrex/README.md
Last active Aug 29, 2015

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Park walk

Auto-centering and auto-scaling topojson data with an inkpen-style drawing animation.

<!DOCTYPE html>
<head>
<meta charset='utf-8'>
<style>
path {
fill: none;
stroke: #D7181E;
stroke-opacity: 0.8;
stroke-linecap: round;
stroke-linejoin: round;
}
</style>
</head>
<body>
<script src='http://d3js.org/d3.v3.min.js'></script>
<script src='http://d3js.org/topojson.v1.min.js'></script>
<script>
var width = 960;
var height = 500;
var margin = 20;
var pathWidths = [1, 2, 3, 4, 5];
var svg = d3.select('body').append('svg')
.attr('width', width)
.attr('height', height);
width = width - 2*margin;
height = height - 2*margin;
d3.json('map.json', function(error, map) {
var feature = topojson.feature(map, map.objects.collection).features[0];
var center = d3.geo.centroid(feature);
var scale = 150;
var offset = [width/2, height/2];
var projection = d3.geo.mercator()
.scale(scale)
.center(center)
.translate(offset);
var path = d3.geo.path().projection(projection);
var bounds = path.bounds(feature);
var hscale = scale * width / (bounds[1][0] - bounds[0][0]);
var vscale = scale * height / (bounds[1][1] - bounds[0][1]);
var scale = (hscale < vscale) ? hscale : vscale;
projection = d3.geo.mercator()
.scale(scale)
.center(center);
path = d3.geo.path()
.projection(projection);
var group = svg.selectAll('g')
.data(topojson.feature(map, map.objects.collection).features)
group.enter().append('g')
.each(function(data) {
d3.select(this).selectAll('path')
.data(pathWidths).enter()
.append('path')
.attr('d', function() { return path(data); })
.style('stroke-width', function(d) { return d; })
.style('stroke-dasharray', '0,10000')
.transition()
.delay(function(d, i) { return i * 50 + 500; })
.duration(5000)
.ease('linear')
.style('stroke-dasharray', '2000,10000');
});
});
</script>
</body>
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