An example of d3.behavior.zoom and d3.geo.path. By modifying the transform, the browser can rapidly redraw geographic features while panning and zooming, without the overhead of reprojection. This technique can be extended by combining with d3.geo.tile.
-
-
Save BruOp/fa7b65d71282cda3ce58 to your computer and use it in GitHub Desktop.
This file contains hidden or 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
| .DS_Store | |
| build | |
| node_modules | |
| Makefile |
This file contains hidden or 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
| #!/usr/bin/env node | |
| var fs = require("fs"); | |
| var idProperty = process.argv[2], | |
| collection = JSON.parse(fs.readFileSync("/dev/stdin")), | |
| featureIds = {}; | |
| collection.features = collection.features.filter(function(feature) { | |
| var id = feature.properties[idProperty]; | |
| if (id == null) throw new Error("id is required for geouniq"); | |
| if (!(id in featureIds)) { | |
| featureIds[id] = 1; | |
| return true; | |
| } | |
| }); | |
| console.log(JSON.stringify(collection)); |
This file contains hidden or 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> | |
| .overlay { | |
| fill: none; | |
| pointer-events: all; | |
| } | |
| .state { | |
| fill: #aaa; | |
| } | |
| .county-border, | |
| .state-border { | |
| fill: none; | |
| stroke: #fff; | |
| stroke-linejoin: round; | |
| stroke-linecap: round; | |
| } | |
| </style> | |
| <body> | |
| <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js"></script> | |
| <script src="https://cdnjs.cloudflare.com/ajax/libs/topojson/1.6.19/topojson.min.js"></script> | |
| <script> | |
| var width = 960, | |
| height = 500; | |
| var path = d3.geo.path() | |
| .projection(null); | |
| var zoom = d3.behavior.zoom() | |
| .translate([0, 0]) | |
| .scale(1) | |
| .scaleExtent([1, 8]) | |
| .on("zoom", zoomed); | |
| var svg = d3.select("body").append("svg") | |
| .attr("width", width) | |
| .attr("height", height); | |
| var features = svg.append("g"); | |
| svg.append("rect") | |
| .attr("class", "overlay") | |
| .attr("width", width) | |
| .attr("height", height) | |
| .call(zoom); | |
| d3.json("us.json", function(error, us) { | |
| if (error) throw error; | |
| features.append("path") | |
| .datum(topojson.feature(us, us.objects.states)) | |
| .attr("class", "state") | |
| .attr("d", path); | |
| features.append("path") | |
| .datum(topojson.mesh(us, us.objects.states, function(a, b) { return a !== b; })) | |
| .attr("class", "state-border") | |
| .attr("d", path) | |
| .style("stroke-width", "1.5px"); | |
| features.append("path") | |
| .datum(topojson.mesh(us, us.objects.counties, function(a, b) { return a !== b && !(a.id / 1000 ^ b.id / 1000); })) | |
| .attr("class", "county-border") | |
| .attr("d", path) | |
| .style("stroke-width", ".5px"); | |
| }); | |
| function zoomed() { | |
| features.attr("transform", "translate(" + d3.event.translate + ")scale(" + d3.event.scale + ")"); | |
| features.select(".state-border").style("stroke-width", 1.5 / d3.event.scale + "px"); | |
| features.select(".county-border").style("stroke-width", .5 / d3.event.scale + "px"); | |
| } | |
| d3.select(self.frameElement).style("height", height + "px"); | |
| </script> |
This file contains hidden or 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
| { | |
| "name": "anonymous", | |
| "version": "0.0.1", | |
| "private": true, | |
| "devDependencies": { | |
| "topojson": "1" | |
| } | |
| } |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment