d3-voronoi-treemap usage

This block illustrates the use of the d3-voronoi-treemap plugin. This block is a remake of the HowMuch.net's article The Global Economy by GDP.

The d3-voronoi-treemap plugin produces Voronoï treemap. Given a convex polygon (here, a 60-gon representing our Earth) and nested weighted data, it tesselates/partitions the polygon in several inner cells which represent the hierarchical structure of your data, such that the area of a cell represents the weight of the underlying datum.

Acknowledgments to :

D3.js (v.6)
d3-voronoi-treemap plugin
blockbuilder.org
(part of) https://github.com/ArlindNocaj/Voronoi-Treemap-Library for a Java implementation

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>d3-voronoi-treemap usage</title>
    <meta name="description" content="d3-voronoi-treemap plugin to remake 'The Costs of Being Fat, in Actual Dollars'">
    <script src="https://d3js.org/d3.v6.min.js" charset="utf-8"></script>
    <script src="https://rawcdn.githack.com/kcnarf/d3-weighted-voronoi/v1.0.1/build/d3-weighted-voronoi.js"></script>
    <script src="https://rawcdn.githack.com/kcnarf/d3-voronoi-map/v2.0.1/build/d3-voronoi-map.js"></script>
    <script src="https://rawcdn.githack.com/kcnarf/d3-voronoi-treemap/v1.1.1/build/d3-voronoi-treemap.js"></script>
    <style>
      svg {
        background-color: rgb(250,250,250);
      }
      
      #title {
        letter-spacing: 4px;
        font-weight: 700;
        font-size: x-large;
      }
      
      text.tiny {
        font-size: 10pt;
      }
      text.light {
        fill: lightgrey
      }
      
      .world {
        stroke: lightgrey;
		    stroke-width: 4px;
      }
      
      .cell {
        stroke: white;
        stroke-width: 1px;
      }
      
      .label {
        text-anchor: middle;
        fill: white;
      }
      
      .label>.name {
        dominant-baseline: text-after-edge;
      }
      
      .label>.value {
        dominant-baseline: text-before-edge;
      }
      
      .hoverer {
        fill: transparent;
        stroke: white;
        stroke-width:0px;
      }
      
      .hoverer:hover {
        stroke-width: 3px;
      }
      
      .legend-color {
        stroke-width: 1px;
        stroke:darkgrey;
      }
    </style>
  </head>
  <body>
    <svg></svg>
    
    <script>
      //begin: constants
      var _2PI = 2*Math.PI;
      //end: constants
      
      //begin: layout conf.
      var svgWidth = 960,
          svgHeight = 500,
          margin = {top: 10, right: 10, bottom: 10, left: 10},
          height = svgHeight - margin.top - margin.bottom,
          width = svgWidth - margin.left - margin.right,
          halfWidth = width/2,
          halfHeight = height/2,
          quarterWidth = width/4,
          quarterHeight = height/4,
          titleY = 20,
          legendsMinY = height - 20,
          treemapRadius = 205,
          treemapCenter = [halfWidth, halfHeight+5];
      //end: layout conf.
      
      //begin: treemap conf.
      var _voronoiTreemap = d3.voronoiTreemap();
      var hierarchy, circlingPolygon;
      //end: treemap conf.
      
      //begin: drawing conf.
      var fontScale = d3.scaleLinear();
      //end: drawing conf.
      
      //begin: reusable d3Selection
      var svg, drawingArea, treemapContainer;
      //end: reusable d3Selection
      
      d3.json("globalEconomyByGDP.json").then(function(rootData) {
        initData();
        initLayout(rootData);
        hierarchy = d3.hierarchy(rootData).sum(function(d){ return d.weight; });
        _voronoiTreemap
          .clip(circlingPolygon)
        	(hierarchy);
        
        drawTreemap(hierarchy);
      });
      
      function initData(rootData) {
        circlingPolygon = computeCirclingPolygon(treemapRadius);
        fontScale.domain([3, 20]).range([8, 20]).clamp(true);
      }
      
      function computeCirclingPolygon(radius) {
        var points = 60,
            increment = _2PI/points,
            circlingPolygon = [];
        
        for (var a=0, i=0; i<points; i++, a+=increment) {
          circlingPolygon.push(
            [radius + radius*Math.cos(a), radius + radius*Math.sin(a)]
          )
        }
        
      	return circlingPolygon;
      };
      
      function initLayout(rootData) {
        svg = d3.select("svg")
          .attr("width", svgWidth)
          .attr("height", svgHeight);
        
        drawingArea = svg.append("g")
        	.classed("drawingArea", true)
        	.attr("transform", "translate("+[margin.left,margin.top]+")");
        
        treemapContainer = drawingArea.append("g")
        	.classed("treemap-container", true)
        	.attr("transform", "translate("+treemapCenter+")");
        
        treemapContainer.append("path")
        	.classed("world", true)
        	.attr("transform", "translate("+[-treemapRadius,-treemapRadius]+")")
        	.attr("d", "M"+circlingPolygon.join(",")+"Z");
        
        drawTitle();
        drawFooter();
        drawLegends(rootData);
      }
      
      function drawTitle() {
        drawingArea.append("text")
        	.attr("id", "title")
        	.attr("transform", "translate("+[halfWidth, titleY]+")")
        	.attr("text-anchor", "middle")
          .text("The Global Economy by GDP (as of 01/2017)")
      }
      
      function drawFooter() {
        drawingArea.append("text")
        	.classed("tiny light", true)
        	.attr("transform", "translate("+[0, height]+")")
        	.attr("text-anchor", "start")
        	.text("Remake of HowMuch.net's article 'The Global Economy by GDP'")
        drawingArea.append("text")
        	.classed("tiny light", true)
        	.attr("transform", "translate("+[halfWidth, height]+")")
        	.attr("text-anchor", "middle")
        	.text("by @_Kcnarf")
        drawingArea.append("text")
        	.classed("tiny light", true)
        	.attr("transform", "translate("+[width, height]+")")
        	.attr("text-anchor", "end")
        	.text("bl.ocks.org/Kcnarf/fa95aa7b076f537c00aed614c29bb568")
      }
      
      function drawLegends(rootData) {
        var legendHeight = 13,
            interLegend = 4,
            colorWidth = legendHeight*6,
            continents = rootData.children.reverse();
        
        var legendContainer = drawingArea.append("g")
        	.classed("legend", true)
        	.attr("transform", "translate("+[0, legendsMinY]+")");
        
        var legends = legendContainer.selectAll(".legend")
        	.data(continents)
        	.enter();
        
        var legend = legends.append("g")
        	.classed("legend", true)
        	.attr("transform", function(d,i){
            return "translate("+[0, -i*(legendHeight+interLegend)]+")";
          })
        	
        legend.append("rect")
        	.classed("legend-color", true)
        	.attr("y", -legendHeight)
        	.attr("width", colorWidth)
        	.attr("height", legendHeight)
        	.style("fill", function(d){ return d.color; });
        legend.append("text")
        	.classed("tiny", true)
        	.attr("transform", "translate("+[colorWidth+5, -2]+")")
        	.text(function(d){ return d.name; });
        
        legendContainer.append("text")
        	.attr("transform", "translate("+[0, -continents.length*(legendHeight+interLegend)-5]+")")
          .text("Continents");
      }
      
      function drawTreemap(hierarchy) {
        var leaves=hierarchy.leaves();
        
        var cells = treemapContainer.append("g")
        	.classed('cells', true)
        	.attr("transform", "translate("+[-treemapRadius,-treemapRadius]+")")
	        .selectAll(".cell")
        	.data(leaves)
        	.enter()
        		.append("path")
        			.classed("cell", true)
        			.attr("d", function(d){ return "M"+d.polygon.join(",")+"z"; })
        			.style("fill", function(d){
                return d.parent.data.color;
          		});
        
        var labels = treemapContainer.append("g")
        	.classed('labels', true)
        	.attr("transform", "translate("+[-treemapRadius,-treemapRadius]+")")
	        .selectAll(".label")
        	.data(leaves)
        	.enter()
        		.append("g")
        			.classed("label", true)
        			.attr("transform", function(d){
          			return "translate("+[d.polygon.site.x, d.polygon.site.y]+")";
              })
        			.style("font-size", function(d){ return fontScale(d.data.weight); });
        
        labels.append("text")
        	.classed("name", true)
        	.html(function(d){
          	return (d.data.weight<1)? d.data.code : d.data.name;
        	});
        labels.append("text")
        	.classed("value", true)
        	.text(function(d){ return d.data.weight+"%"; });
        
        var hoverers = treemapContainer.append("g")
        	.classed('hoverers', true)
        	.attr("transform", "translate("+[-treemapRadius,-treemapRadius]+")")
	        .selectAll(".hoverer")
        	.data(leaves)
        	.enter()
        		.append("path")
        			.classed("hoverer", true)
        			.attr("d", function(d){ return "M"+d.polygon.join(",")+"z"; });
        
        hoverers.append("title")
          .text(function(d) { return d.data.name + "\n" + d.value+"%"; });
      }
    </script>
  </body>
</html>

Updated missing url https://rawcdn.githack.com/Kcnarf/d3-weighted-voronoi/v1.0.1/build/d3-weighted-voronoi.js to https://rawcdn.githack.com/kcnarf/d3-weighted-voronoi/v1.0.1/build/d3-weighted-voronoi.js

Updated missing url https://rawcdn.githack.com/Kcnarf/d3-voronoi-map/v2.0.1/build/d3-voronoi-map.js to https://rawcdn.githack.com/kcnarf/d3-voronoi-map/v2.0.1/build/d3-voronoi-map.js

Updated missing url https://rawcdn.githack.com/Kcnarf/d3-voronoi-treemap/v1.1.1/build/d3-voronoi-treemap.js to https://rawcdn.githack.com/kcnarf/d3-voronoi-treemap/v1.1.1/build/d3-voronoi-treemap.js

https://d3js.org/d3.v6.min.js

https://rawcdn.githack.com/Kcnarf/d3-weighted-voronoi/v1.0.1/build/d3-weighted-voronoi.js

https://rawcdn.githack.com/Kcnarf/d3-voronoi-map/v2.0.1/build/d3-voronoi-map.js

https://rawcdn.githack.com/Kcnarf/d3-voronoi-treemap/v1.1.1/build/d3-voronoi-treemap.js