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@mpmckenna8
Last active August 29, 2015 14:03
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Gnomic projection rotating around North Pole d3.js

This is more or less what I was trying to do with the first transitioning gnomic projection example but I backtracked and tried to make use of this d3.timer() thing. I want to experiment changing the values I give to projection.rotate() and also see if I can figure out how to done rotate it a bit smoother using transitions or tweens or some such thing.

See these other poorly done gnomic d3 attempts:

I pretty much stole the rotating function in d3.timer() from http://bl.ocks.org/mbostock/5731578 which looks much smoother with a spherical (round) projections. I don't really know what I'm talking about yet though and need to do some more research and experimenting.

<!DOCTYPE html>
<meta charset="utf-8">
<style>
.graticule {
fill: none;
stroke: rgb(243, 255, 107);
stroke-width: 1.5px;
stroke-opacity: .5;
}
.land {
fill: rgb(229, 110, 255);
}
.boundary {
fill: none;
stroke:rgb(229, 110, 255);
stroke-width: .5px;
}
</style>
<body>
<script src="http://d3js.org/d3.v3.js"></script>
<script src="http://d3js.org/topojson.v1.min.js"></script>
<script>
var width = 960,
height = 960,
// should try changing the rotate values. think first at 0 stops rolling hemispheres, tho I kind of like that.
rotate = [5, -90],
velocity = [.003, 0.000],
time = Date.now();
var projection = d3.geo.gnomonic()
.clipAngle(90 - 1e-3)
.scale(150)
.translate([width/2, height / 2])
.precision(.1)
// rotate([yaw, pitch, roll]) or long lat and roll
// This was unnecessary .rotate([0,0 ,25])
// .center([-240,20])
var path = d3.geo.path()
.projection(projection);
var graticule = d3.geo.graticule();
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height);
svg.append("path")
.datum(graticule)
.attr("class", "graticule")
.attr("d", path);
d3.json("/mpmckenna8/raw/9965876/world-50m.json", function(error, world) {
svg.insert("path", ".graticule")
.datum(topojson.feature(world, world.objects.land))
.attr("class", "land")
.attr("d", path);
svg.insert("path", ".graticule")
.datum(topojson.mesh(world, world.objects.countries, function(a, b) { return a !== b; }))
.attr("class", "boundary")
.attr("d", path);
var feature = svg.selectAll("path");
d3.timer(function(){
var dt = Date.now() - time;
projection.rotate([rotate[0] + velocity[0] * dt, rotate[1] + velocity[1] * dt]);
feature.attr("d", path);
})
d3.selectAll('.land')
.transition()
.delay(699)
.duration(69999)
.style("fill","rgb(108, 255, 110)");
});
d3.select('svg')
.style('background', 'rgb(108, 129, 255)')
d3.select(self.frameElement).style("height", height + "px");
</script>
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