A version of Mike Bostock’s animated world countries, which uses a more accurate spherical interpolation.
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World Countries
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<!DOCTYPE html> | |
<meta charset="utf-8"> | |
<style> | |
.country { | |
fill: #b8b8b8; | |
stroke: #fff; | |
stroke-width: .5px; | |
stroke-linejoin: round; | |
} | |
.graticule { | |
fill: none; | |
stroke: #000; | |
stroke-opacity: .3; | |
stroke-width: .5px; | |
} | |
.graticule-outline { | |
fill: none; | |
stroke: #333; | |
stroke-width: 1.5px; | |
} | |
text { | |
font-family: "Helvetica Neue", Helvetica, Arial, sans-serif; | |
font-size: 18px; | |
font-weight: bold; | |
text-anchor: middle; | |
} | |
</style> | |
<body> | |
<script src="http://d3js.org/d3.v3.min.js"></script> | |
<script src="http://d3js.org/topojson.v0.min.js"></script> | |
<script> | |
var width = 960, | |
height = 500; | |
var centroid = d3.geo.path() | |
.projection(function(d) { return d; }) | |
.centroid; | |
var projection = d3.geo.orthographic() | |
.scale(248) | |
.clipAngle(90); | |
var path = d3.geo.path() | |
.projection(projection); | |
var graticule = d3.geo.graticule() | |
.extent([[-180, -90], [180 - .1, 90 - .1]]); | |
var svg = d3.select("body").append("svg") | |
.attr("width", width) | |
.attr("height", height); | |
var line = svg.append("path") | |
.datum(graticule) | |
.attr("class", "graticule") | |
.attr("d", path); | |
svg.append("circle") | |
.attr("class", "graticule-outline") | |
.attr("cx", width / 2) | |
.attr("cy", height / 2) | |
.attr("r", projection.scale()); | |
var title = svg.append("text") | |
.attr("x", width / 2) | |
.attr("y", height * 3 / 5); | |
var rotate = d3_geo_greatArcInterpolator(); | |
d3.json("readme-world-110m.json", function(error, world) { | |
var countries = topojson.object(world, world.objects.countries).geometries, | |
i = -1, | |
n = countries.length; | |
var country = svg.selectAll(".country") | |
.data(countries) | |
.enter().insert("path", ".graticule") | |
.attr("class", "country") | |
.attr("d", path); | |
step(); | |
function step() { | |
if (++i >= n) i = 0; | |
title.text(countries[i].id); | |
country.transition() | |
.style("fill", function(d, j) { return j === i ? "red" : "#b8b8b8"; }); | |
d3.transition() | |
.delay(250) | |
.duration(1250) | |
.tween("rotate", function() { | |
var point = centroid(countries[i]); | |
rotate.source(projection.rotate()).target([-point[0], -point[1]]).distance(); | |
return function(t) { | |
projection.rotate(rotate(t)); | |
country.attr("d", path); | |
line.attr("d", path); | |
}; | |
}) | |
.transition() | |
.each("end", step); | |
} | |
}); | |
var d3_radians = Math.PI / 180; | |
function d3_geo_greatArcInterpolator() { | |
var x0, y0, cy0, sy0, kx0, ky0, | |
x1, y1, cy1, sy1, kx1, ky1, | |
d, | |
k; | |
function interpolate(t) { | |
var B = Math.sin(t *= d) * k, | |
A = Math.sin(d - t) * k, | |
x = A * kx0 + B * kx1, | |
y = A * ky0 + B * ky1, | |
z = A * sy0 + B * sy1; | |
return [ | |
Math.atan2(y, x) / d3_radians, | |
Math.atan2(z, Math.sqrt(x * x + y * y)) / d3_radians | |
]; | |
} | |
interpolate.distance = function() { | |
if (d == null) k = 1 / Math.sin(d = Math.acos(Math.max(-1, Math.min(1, sy0 * sy1 + cy0 * cy1 * Math.cos(x1 - x0))))); | |
return d; | |
}; | |
interpolate.source = function(_) { | |
var cx0 = Math.cos(x0 = _[0] * d3_radians), | |
sx0 = Math.sin(x0); | |
cy0 = Math.cos(y0 = _[1] * d3_radians); | |
sy0 = Math.sin(y0); | |
kx0 = cy0 * cx0; | |
ky0 = cy0 * sx0; | |
d = null; | |
return interpolate; | |
}; | |
interpolate.target = function(_) { | |
var cx1 = Math.cos(x1 = _[0] * d3_radians), | |
sx1 = Math.sin(x1); | |
cy1 = Math.cos(y1 = _[1] * d3_radians); | |
sy1 = Math.sin(y1); | |
kx1 = cy1 * cx1; | |
ky1 = cy1 * sx1; | |
d = null; | |
return interpolate; | |
}; | |
return interpolate; | |
} | |
</script> |
Heh....nevermind. I wasn't setting the 'd' attribute on country
or line
. Still figuring out how to use lat/long though.
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I've tried to boil this down a little simpler and do a single rotation to a given lat/long (that's a valid point in a geo projection, right?) and am not having much success. I replaced lines 87 - 112 with the following:
Nothing at all happens, and I'm a little bit at a loss as to why. Would you mind correcting me on what I've missed?