detect olverapped SVG elements intersections

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
  </style>
</head>

<body>
  <script>
    
	// https://stackoverflow.com/questions/16799116/handling-mouse-events-in-overlapping-svg-layers
    function passThru(d) {
        
        console.log("selected color: ", d3.select(this).style("fill"))
        var e = d3.event;

var prev = this.style.pointerEvents;
        this.style.pointerEvents = 'none';

var el = document.elementFromPoint(d3.event.x, d3.event.y);

var e2 = document.createEvent('MouseEvent');
         
        e2.initMouseEvent(e.type,e.bubbles,e.cancelable,e.view, e.detail,e.screenX,e.screenY,e.clientX,e.clientY,e.ctrlKey,e.altKey,e.shiftKey,e.metaKey,e.button,e.relatedTarget);

el.dispatchEvent(e2);

this.style.pointerEvents = prev;
    }
    
    
    var svg = d3.select("body").append("svg")
      .attr("width", 960)
      .attr("height", 500)
    
    svg.append("circle")
      .attr("cy", 150)
      .attr("cx", 150)
      .attr("r", 150)
    	.style("fill", "red")
    	.style("opacity", .2)
      .on("click", passThru);
    
    svg.append("circle")
      .attr("cy", 200)
      .attr("cx", 350)
      .attr("r", 150)
    	.style("fill", "green")
    	.style("opacity", .2)
      .on("click", passThru);
    
    svg.append("circle")
      .attr("cy", 300)
      .attr("cx", 250)
      .attr("r", 150)
    	.style("fill", "yellow")
    	.style("opacity", .2)
      .on("click", passThru);
   
    
  </script>
</body>

https://d3js.org/d3.v4.min.js