-
-
Save tjmw/3d20a6955464d85d1d05 to your computer and use it in GitHub Desktop.
D3 Projections
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| var width = 960, | |
| height = 500; | |
| var projection = interpolatedProjection( | |
| d3.geo.orthographic() | |
| .rotate([10, -10]) | |
| .center([-10, 10]) | |
| .scale(240) | |
| .translate([width / 2, height / 2]), | |
| d3.geo.equirectangular() | |
| .scale(145) | |
| .translate([width / 2, height / 2])); | |
| 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({type: "Sphere"}) | |
| .attr("class", "sphere") | |
| .attr("d", path); | |
| svg.append("path") | |
| .datum(graticule) | |
| .attr("class", "graticule") | |
| .attr("d", path); | |
| svg.append("path") | |
| .datum({type: "LineString", coordinates: [[-180, 0], [-90, 0], [0, 0], [90, 0], [180, 0]]}) | |
| .attr("class", "equator") | |
| .attr("d", path); | |
| var feature = svg.selectAll("path"); | |
| animation(); | |
| function animation() { | |
| svg.transition() | |
| .duration(7500) | |
| .tween("projection", function() { | |
| return function(_) { | |
| projection.alpha(_); | |
| feature.attr("d", path); | |
| }; | |
| }) | |
| .transition() | |
| .duration(2500) | |
| .each("end", animation); | |
| } | |
| function interpolatedProjection(a, b) { | |
| var projection = d3.geo.projection(raw).scale(1), | |
| center = projection.center, | |
| translate = projection.translate, | |
| α; | |
| function raw(λ, φ) { | |
| var pa = a([λ *= 180 / Math.PI, φ *= 180 / Math.PI]), pb = b([λ, φ]); | |
| return [(1 - α) * pa[0] + α * pb[0], (α - 1) * pa[1] - α * pb[1]]; | |
| } | |
| projection.alpha = function(_) { | |
| if (!arguments.length) return α; | |
| α = +_; | |
| var ca = a.center(), cb = b.center(), | |
| ta = a.translate(), tb = b.translate(); | |
| center([(1 - α) * ca[0] + α * cb[0], (1 - α) * ca[1] + α * cb[1]]); | |
| translate([(1 - α) * ta[0] + α * tb[0], (1 - α) * ta[1] + α * tb[1]]); | |
| return projection; | |
| }; | |
| delete projection.scale; | |
| delete projection.translate; | |
| delete projection.center; | |
| return projection.alpha(0); | |
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| <!DOCTYPE html> | |
| <meta charset="utf-8"> | |
| <style> | |
| path { | |
| fill: none; | |
| stroke-linejoin: round; | |
| } | |
| .sphere, | |
| .graticule { | |
| stroke: #aaa; | |
| } | |
| .equator { | |
| stroke: blue; | |
| stroke-width: 2px; | |
| } | |
| </style> | |
| <body> | |
| <script src="http://d3js.org/d3.v3.min.js"></script> | |
| <script src="app.js"></script> |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment