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AmineS/d3 in node

Created August 2, 2013 04:50
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  1. AmineS created this gist Aug 2, 2013.
    68 changes: 68 additions & 0 deletions d3 in node
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,68 @@
    require("../../test/env");

    var fs = require("fs"),
    util = require("util"),
    Canvas = require("canvas");

    var w = 1920,
    h = 1080;

    var projection = d3.geo.albersUsa()
    .scale(2000)
    .translate([w / 2, h / 2]);

    var path = d3.geo.path()
    .projection(projection);

    var canvas = new Canvas(w, h),
    context = canvas.getContext("2d");

    context.antialias = "none";
    context.lineWidth = 8;
    context.lineJoin = "round";

    d3.json(__dirname + "/../data/us-counties.json", function(collection) {
    renderAll("stroke");
    renderAll("fill");
    fs.writeFile("us-counties.png", canvas.toBuffer());

    function renderAll(action) {
    collection.features.forEach(function(feature) {
    var re = /[MLZ]/g,
    d = path(feature),
    i = 0,
    m;

    context[action + "Style"] = "#" + pad((+feature.id).toString(16));
    context.beginPath();
    re.lastIndex = 1;
    while (m = re.exec(d)) render(m.index);
    render();
    context[action]();

    function render(j) {
    switch (d.charAt(i)) {
    case "M": {
    var p = d.substring(i + 1, j).split(",").map(Number);
    context.moveTo(p[0], p[1]);
    break;
    }
    case "L": {
    var p = d.substring(i + 1, j).split(",").map(Number);
    context.lineTo(p[0], p[1]);
    break;
    }
    case "Z": {
    context.closePath();
    break;
    }
    }
    i = j;
    }
    });
    }
    });

    function pad(s) {
    return s.length < 6 ? new Array(7 - s.length).join("0") + s : s;
    }