Coloring of three intersecting regions

Same as this example, but supporting the intersection of three regions. The code could be easily generalized to more regions.

xxxxxxxxxx
 
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="description" content="Coloring of intersecting regions"/>
    <title>Coloring of intersecting regions</title>
    <script src="https://d3js.org/d3.v3.min.js"></script>
  </head>
  <body>
    <svg width="960" height="500">
    </svg>
  <script src="index.js"></script>
</html>
    

Modified http://d3js.org/d3.v3.min.js to a secure url

https://d3js.org/d3.v3.min.js